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Vincent Kam Wai Wong

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DOI: 10.1038/s41467-021-23448-7
2021
Cited 99 times
A small molecule HIF-1α stabilizer that accelerates diabetic wound healing
Abstract Impaired wound healing and ulcer complications are a leading cause of death in diabetic patients. In this study, we report the design and synthesis of a cyclometalated iridium(III) metal complex 1a as a stabilizer of hypoxia-inducible factor-1α (HIF-1α). In vitro biophysical and cellular analyses demonstrate that this compound binds to Von Hippel-Lindau (VHL) and inhibits the VHL–HIF-1α interaction. Furthermore, the compound accumulates HIF-1α levels in cellulo and activates HIF-1α mediated gene expression, including VEGF , GLUT1 , and EPO . In in vivo mouse models, the compound significantly accelerates wound closure in both normal and diabetic mice, with a greater effect being observed in the diabetic group. We also demonstrate that HIF-1α driven genes related to wound healing (i.e. HSP-90 , VEGFR-1 , SDF-1 , SCF , and Tie-2 ) are increased in the wound tissue of 1a -treated diabetic mice (including, db / db , HFD/STZ and STZ models). Our study demonstrates a small molecule stabilizer of HIF-1α as a promising therapeutic agent for wound healing, and, more importantly, validates the feasibility of treating diabetic wounds by blocking the VHL and HIF-1α interaction.
DOI: 10.1016/j.jhep.2020.09.019
2021
Cited 76 times
Dicoumarol, an NQO1 inhibitor, blocks cccDNA transcription by promoting degradation of HBx
•Dicoumarol, a competitive NADPH quinone oxidoreductase (NQO1) inhibitor, is identified as an inhibitor of HBx expression.•NQO1 stabilises HBx protein by inhibiting 20S proteasome-mediated protein degradation.•NQO1 knockdown or dicoumarol treatment blocks cccDNA transcription by establishing a repressive chromatin structure.•Dicoumarol exhibits potent antiviral activity in HBV-infected hepatocytes and a humanised liver mouse model. Background & AimsCurrent antiviral therapies help keep HBV under control, but they are not curative, as they are unable to eliminate the intracellular viral replication intermediate termed covalently closed circular DNA (cccDNA). Therefore, there remains an urgent need to develop strategies to cure CHB. Functional silencing of cccDNA is a crucial curative strategy that may be achieved by targeting the viral protein HBx.MethodsWe screened 2,000 small-molecule compounds for their ability to inhibit HiBiT-tagged HBx (HiBiT-HBx) expression by using a HiBiT lytic detection system. The antiviral activity of a candidate compound and underlying mechanism of its effect on cccDNA transcription were evaluated in HBV-infected cells and a humanised liver mouse model.ResultsDicoumarol, an inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), significantly reduced HBx expression. Moreover, dicoumarol showed potent antiviral activity against HBV RNAs, HBV DNA, HBsAg and HBc protein in HBV-infected cells and a humanised liver mouse model. Mechanistic studies demonstrated that endogenous NQO1 binds to and protects HBx protein from 20S proteasome-mediated degradation. NQO1 knockdown or dicoumarol treatment significantly reduced the recruitment of HBx to cccDNA and inhibited the transcriptional activity of cccDNA, which was associated with the establishment of a repressive chromatin state. The absence of HBx markedly blocked the antiviral effect induced by NQO1 knockdown or dicoumarol treatment in HBV-infected cells.ConclusionsHerein, we report on a novel small molecule that targets HBx to combat chronic HBV infection; we also reveal that NQO1 has a role in HBV replication through the regulation of HBx protein stability.Lay summaryCurrent antiviral therapies for hepatitis B are not curative because of their inability to eliminate covalently closed circular DNA (cccDNA), which persists in the nuclei of infected cells. HBV X (HBx) protein has an important role in regulating cccDNA transcription. Thus, targeting HBx to silence cccDNA transcription could be an important curative strategy. We identified that the small molecule dicoumarol could block cccDNA transcription by promoting HBx degradation; this is a promising therapeutic strategy for the treatment of chronic hepatitis B. Current antiviral therapies help keep HBV under control, but they are not curative, as they are unable to eliminate the intracellular viral replication intermediate termed covalently closed circular DNA (cccDNA). Therefore, there remains an urgent need to develop strategies to cure CHB. Functional silencing of cccDNA is a crucial curative strategy that may be achieved by targeting the viral protein HBx. We screened 2,000 small-molecule compounds for their ability to inhibit HiBiT-tagged HBx (HiBiT-HBx) expression by using a HiBiT lytic detection system. The antiviral activity of a candidate compound and underlying mechanism of its effect on cccDNA transcription were evaluated in HBV-infected cells and a humanised liver mouse model. Dicoumarol, an inhibitor of NAD(P)H:quinone oxidoreductase 1 (NQO1), significantly reduced HBx expression. Moreover, dicoumarol showed potent antiviral activity against HBV RNAs, HBV DNA, HBsAg and HBc protein in HBV-infected cells and a humanised liver mouse model. Mechanistic studies demonstrated that endogenous NQO1 binds to and protects HBx protein from 20S proteasome-mediated degradation. NQO1 knockdown or dicoumarol treatment significantly reduced the recruitment of HBx to cccDNA and inhibited the transcriptional activity of cccDNA, which was associated with the establishment of a repressive chromatin state. The absence of HBx markedly blocked the antiviral effect induced by NQO1 knockdown or dicoumarol treatment in HBV-infected cells. Herein, we report on a novel small molecule that targets HBx to combat chronic HBV infection; we also reveal that NQO1 has a role in HBV replication through the regulation of HBx protein stability.
DOI: 10.1002/anie.201807305
2018
Cited 128 times
Selective Inhibition of Lysine‐Specific Demethylase 5A (KDM5A) Using a Rhodium(III) Complex for Triple‐Negative Breast Cancer Therapy
Abstract Lysine‐specific demethylase 5A (KDM5A) has recently become a promising target for epigenetic therapy. In this study, we designed and synthesized metal complexes bearing ligands with reported demethylase and p27 modulating activities. The Rh(III) complex 1 was identified as a direct, selective and potent inhibitor of KDM5A that directly abrogate KDM5A demethylase activity via antagonizing the KDM5A‐tri‐/di‐methylated histone 3 protein–protein interaction (PPI) in vitro and in cellulo. Complex 1 induced accumulation of H3K4me3 and H3K4me2 levels in cells, causing growth arrest at G1 phase in the triple‐negative breast cancer (TNBC) cell lines, MDA‐MB‐231 and 4T1. Finally, 1 exhibited potent anti‐tumor activity against TNBC xenografts in an in vivo mouse model, presumably via targeting of KDM5A and hence upregulating p27. Moreover, complex 1 was less toxic compared with two clinical drugs, cisplatin and doxorubicin. To our knowledge, complex 1 is the first metal‐based KDM5A inhibitor reported in the literature. We anticipate that complex 1 may be used as a novel scaffold for the further development of more potent epigenetic agents against cancers, including TNBC.
DOI: 10.1016/j.phrs.2021.105820
2021
Cited 60 times
Identification of natural compounds as SARS-CoV-2 entry inhibitors by molecular docking-based virtual screening with bio-layer interferometry
Coronavirus Disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which enter the host cells through the interaction between its receptor binding domain (RBD) of spike glycoprotein with angiotensin-converting enzyme 2 (ACE2) receptor on the plasma membrane of host cell. Neutralizing antibodies and peptide binders of RBD can block viral infection, however, the concern of accessibility and affordability of viral infection inhibitors has been raised. Here, we report the identification of natural compounds as potential SARS-CoV-2 entry inhibitors using the molecular docking-based virtual screening coupled with bilayer interferometry (BLI). From a library of 1871 natural compounds, epigallocatechin gallate (EGCG), 20(R)-ginsenoside Rg3 (RRg3), 20(S)-ginsenoside Rg3 (SRg3), isobavachalcone (Ibvc), isochlorogenic A (IscA) and bakuchiol (Bkc) effectively inhibited pseudovirus entry at concentrations up to 100 μM. Among these compounds, four compounds, EGCG, Ibvc, salvianolic acid A (SalA), and isoliensinine (Isl), were effective in inhibiting SARS-CoV-2-induced cytopathic effect and plaque formation in Vero E6 cells. The EGCG was further validated with no observable animal toxicity and certain antiviral effect against SARS-CoV-2 pseudovirus mutants (D614G, N501Y, N439K & Y453F). Interestingly, EGCG, Bkc and Ibvc bind to ACE2 receptor in BLI assay, suggesting a dual binding to RBD and ACE2. Current findings shed some insight into identifications and validations of SARS-CoV-2 entry inhibitors from natural compounds.
DOI: 10.1016/j.apsb.2021.10.024
2022
Cited 33 times
Inhibition of the CDK9–cyclin T1 protein–protein interaction as a new approach against triple-negative breast cancer
Cyclin-dependent kinase 9 (CDK9) activity is correlated with worse outcomes of triple-negative breast cancer (TNBC) patients. The heterodimer between CDK9 with cyclin T1 is essential for maintaining the active state of the kinase and targeting this protein-protein interaction (PPI) may offer promising avenues for selective CDK9 inhibition. Herein, we designed and generated a library of metal complexes bearing the 7-chloro-2-phenylquinoline CˆN ligand and tested their activity against the CDK9-cyclin T1 PPI. Complex 1 bound to CDK9 via an enthalpically-driven binding mode, leading to disruption of the CDK9-cyclin T1 interaction in vitro and in cellulo. Importantly, complex 1 showed promising anti-metastatic activity against TNBC allografts in mice and was comparably active compared to cisplatin. To our knowledge, 1 is the first CDK9-cyclin T1 PPI inhibitor with anti-metastatic activity against TNBC. Complex 1 could serve as a new platform for the future design of more efficacious kinase inhibitors against cancer, including TNBC.
DOI: 10.1158/1078-0432.ccr-05-0209
2005
Cited 104 times
Pseudolaric Acid B, a Novel Microtubule-Destabilizing Agent That Circumvents Multidrug Resistance Phenotype and Exhibits Antitumor Activity <i>In vivo</i>
Abstract Purpose: Pseudolaric acid B (PAB) is the major bioactive constituent in the root bark of Pseudolarix kaempferi that has been used as an antifungal remedy in traditional Chinese medicine. Previous studies showed that PAB exhibited substantial cytotoxicity. The aims of this study were to elucidate the molecular target of PAB, to examine its mechanism of action, and to evaluate the efficacy of this compound in vivo. Experimental Design: The effect of PAB on cell growth inhibition toward a panel of cancer cell lines was assayed. Cell cycle analysis, Western blotting, immunocytochemistry, and apoptosis analysis were carried out to examine the mechanism of action. Tubulin polymerization assays were conducted to examine the interaction between PAB and tubulin. A P-glycoprotein–overexpressing cell line was used to evaluate the efficacy of PAB toward multidrug-resistant phenotypes. In vivo efficacy of PAB was evaluated by the murine xenograft model. Results: PAB induces cell cycle arrest at G2-M transition, leading to apoptosis. The drug disrupts cellular microtubule networks and inhibits the formation of mitotic spindles. Polymerization of purified bovine brain tubulin was dose-dependently inhibited by PAB. Furthermore, PAB circumvents the multidrug resistance mechanism, displaying notable potency also in P-glycoprotein–overexpressing cells. Finally, we showed that PAB is effective in inhibiting tumor growth in vivo. Conclusions: We identified the microtubules as the molecular target of PAB. Furthermore, we showed that PAB circumvents P-glycoprotein overexpression-induced drug resistance and is effective in inhibiting tumor growth in vivo. Our work will facilitate the future development of PAB as a cancer therapeutic.
DOI: 10.3389/fphar.2021.634176
2021
Cited 36 times
1,2,3,4,6-Pentagalloyl Glucose, a RBD-ACE2 Binding Inhibitor to Prevent SARS-CoV-2 Infection
The outbreak of SARS-CoV-2 virus caused more than 80,155,187 confirmed COVID-19 cases worldwide, which has posed a serious threat to global public health and the economy. The development of vaccines and discovery of novel drugs for COVID-19 are urgently needed. Although the FDA-approved SARS-CoV-2 vaccines has been launched in many countries recently, the strength of safety, stringent storage condition and the possibly short-term immunized efficacy remain as the major challenges in the popularity and recognition of using vaccines against SARS-CoV-2. With the spike-receptor binding domain (RBD) of SARS-CoV-2 being responsible for binding to human angiotensin-converting enzyme 2 receptor (hACE2), ACE2 is identified as the receptor for the entry and viral infection of SARS-CoV-2. In this study, molecular docking and biolayer interferometry (BLI) binding assay were adopted to determine the direct molecular interactions between natural small-molecule, 1,2,3,4,6-Pentagalloyl glucose (PGG) and the spike-RBD of the SARS-CoV-2. Our results showed that PGG preferentially binds to a pocket that contains residues Glu 340 to Lys 356 of spike-RBD with a relatively low binding energy of -8 kcal/mol. BLI assay further confirmed that PGG exhibits a relatively strong binding affinity to SARS-CoV-2-RBD protein in comparison to hACE2. In addition, both ELISA and immunocytochemistry assay proved that PGG blocks SARS-CoV-2-RBD binding to hACE2 dose dependently in cellular level. Notably, PGG was confirmed to abolish the infectious property of RBD-pseudotyped lentivirus in hACE2 overexpressing HEK293 cells, which mimicked the entry of wild type SARS-CoV-2 virus in human host cells. Finally, maximal tolerated dose (MTD) studies revealed that up to 200 mg/kg/day of PGG was confirmed orally safe in mice. Our findings suggest that PGG may be a safe and potential antiviral agent against the COVID-19 by blockade the fusion of SARS-CoV-2 spike-RBD to hACE2 receptors. Therefore, PGG may be considered as a safe and natural antiviral agent for its possible preventive application in daily anti-virus hygienic products such as a disinfectant spray or face mask.
DOI: 10.1016/j.phrs.2021.105696
2021
Cited 32 times
Potential therapeutic compounds from traditional Chinese medicine targeting endoplasmic reticulum stress to alleviate rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease which affects about 0.5-1% of people with symptoms that significantly impact a sufferer's lifestyle. The cells involved in propagating RA tend to display pro-inflammatory and cancer-like characteristics. Medical drug treatment is currently the main avenue of RA therapy. However, drug options are limited due to severe side effects, high costs, insufficient disease retardation in a majority of patients, and therapeutic effects possibly subsiding over time. Thus there is a need for new drug therapies. Endoplasmic reticulum (ER) stress, a condition due to accumulation of misfolded proteins in the ER, and subsequent cellular responses have been found to be involved in cancer and inflammatory pathologies, including RA. ER stress protein markers and their modulation have therefore been suggested as therapeutic targets, such as GRP78 and CHOP, among others. Some current RA therapeutic drugs have been found to have ER stress-modulating properties. Traditional Chinese Medicines (TCMs) frequently use natural products that affect multiple body and cellular targets, and several medicines and/or their isolated compounds have been found to also have ER stress-modulating capabilities, including TCMs used in RA treatment by Chinese Medicine practitioners. This review encourages, in light of the available information, the study of these RA-treating, ER stress-modulating TCMs as potential new pharmaceutical drugs for use in clinical RA therapy, along with providing a list of other ER stress-modulating TCMs utilized in treatment of cancers, inflammatory diseases and other diseases, that have potential use in RA treatment given similar ER stress-modulating capacity.
DOI: 10.1016/j.phrs.2022.106082
2022
Cited 20 times
Traditional Patchouli essential oil modulates the host’s immune responses and gut microbiota and exhibits potent anti-cancer effects in Apc mice
Patchouli Essential Oil (PEO) has been used as a scent for various healing purposes since the ancient Egyptian period. The primary source of the oil is Pogostemon cablin (PC), a medicinal plant for treating gastrointestinal symptoms. However, the pharmacological function has not been addressed. Here, we report the cancer prevention and gut microbiota (GM) modulating property of PEO and its derivatives patchouli alcohol (PA) and pogostone (PO) in the ApcMin /+ colorectal cancer mice model. We found that PEO, PA, and PO significantly reduced the tumor burden. At the same time, it strengthened the epithelial barrier, evidenced by substantially increasing the number of the goblet and Paneth cells and upregulation of tight junction and adhesion molecules. In addition, PEO, PA, and PO shifted M1 to M2 macrophage phenotypes and remodeled the inflammatory milieu of ApcMin /+ mice. We also found suppression of CD4+CD25+ and stimulation CD4+ CD8+ cells in the spleen, blood, mesenteric lymph nodes (MLNs), and Peyer's patches (PPs) of the treated mice. The composition of the gut microbiome of the drug-treated mice was distinct from the control mice. The drugs stimulated the short-chain fatty acids (SCFAs)-producers and the key SCFA-sensing receptors (GPR41, GPR43, and GPR109a). The activation of SCFAs/GPSs also triggered the alterations of PPAR-γ, PYY, and HSDCs signaling mediators in the treated mice. Our work showed that PEO and its derivatives exert potent anti-cancer effects by modulating gut microbiota and improving the intestinal microenvironment of the ApcMmin /+ mice.
DOI: 10.1016/j.phymed.2022.153941
2022
Cited 19 times
Natural Citrus flavanone 5-demethylnobiletin stimulates melanogenesis through the activation of cAMP/CREB pathway in B16F10 cells
5-demethylnobiletin is a natural polymethoxyflavone which is isolated from the extract of citrus fruits peels. It exhibits a broad spectrum of biological activities such as anti-cancer, anti-inflammatory, cardiovascular protective and neuroprotective effects, however, its effect in melanogenesis remains uninvestigated.Melanin synthesis is a very important biological process in curing disease such as vitiligo with depigmentation on the skin. In the current work, we aim to confirm the bioactivity and mechanism of 5-demethylnobiletin in stimulating melanogenesis.To confirm the mechanistic role of 5-demethylnobiletin in enhancing melanogenesis, its effect on the activity of tyrosinase, together with the level of microphthalmia-associated transcription factor (MITF), Trp-1, Trp-2, melanocyte-specific marker protein PMEL17, Rab27a, Melanophilin and Myosin VA were studied in B16F10 melanoma cells.Multiple biological assays on melanogenesis-associated proteins such as melanin content detection, tyrosinase activity colorimetric assay, qPCR, western blot analysis, dual-luciferase reporter assay, cAMP activity assay and Fontana-Masson ammoniacal silver staining were used to confirm the role of 5-demethylnobiletin in stimulating melanin synthesis and the transportation of melanosomes.As confirmed by multiple biological assays, 5-demethylnobiletin is found to stimulate dendrite structure formation in cells, melanin synthesis and the transportation of melanosomes, via inducing the phosphorylation of cAMP response element-binding protein (CREB) and increasing the intracellular levels of cAMP in vitro through the PKA-dependent pathway.The findings suggested that 5-demethylnobiletin may be considered as a potential natural product candidate for patients with pigment disorder.
DOI: 10.1002/cmdc.201700804
2018
Cited 46 times
Novel Peroxides as Promising Anticancer Agents with Unexpected Depressed Antimalarial Activity
Abstract Twenty six peroxides belonging to bridged 1,2,4,5‐tetraoxanes, bridged 1,2,4‐trioxolanes (ozonides), and tricyclic monoperoxides were evaluated for their in vitro antimalarial activity against Plasmodium falciparum (3D7) and for their cytotoxic activities against immortalized human normal fibroblast (CCD19Lu), liver (LO 2 ), and lung (BEAS‐2B) cell lines as well as human liver (HepG2) and lung (A549) cancer‐cell lines. Synthetic ozonides were shown to have the highest cytotoxicity on HepG2 (IC 50 =0.19–0.59 μ m ), and some of these compounds selectively targeted liver cancer (selectivity index values for compounds 13 a and 14 a are 20 and 28, respectively) at levels that, in some cases, were higher than those of paclitaxel, artemisinin, and artesunic acid. In contrast some ozonides showed only moderate antimalarial activity against the chloroquine‐sensitive 3D7 strain of P. falciparum (IC 50 from 2.76 to 24.2 μ m ; 12 b , IC 50 =2.76 μ m ; 13 a , IC 50 =20.14 μ m ; 14 a , IC 50 =6.32 μ m ). These results suggest that these derivatives have divergent mechanisms of action against cancer cells and malaria‐infected cells. A cyclic voltammetry study of the peroxides was performed, but most of the compounds did not show direct correlation in oxidative capacity–activity. Our findings offer a new source of antimalarial and anticancer agents through structural modification of peroxide compounds.
DOI: 10.1002/cmdc.202000042
2020
Cited 32 times
Synthetic Peroxides Promote Apoptosis of Cancer Cells by Inhibiting P‐Glycoprotein ABCB5
Abstract This article discloses a new horizon for the application of peroxides in medical chemistry. Stable cyclic peroxides are demonstrated to have cytotoxic activity against cancer cells; in addition a mechanism of cytotoxic action is proposed. Synthetic bridged 1,2,4,5‐tetraoxanes and ozonides were effective against HepG2 cancer cells and some ozonides selectively targeted liver cancer cells (the selectivity indexes for compounds 11 b and 12 a are 8 and 5, respectively). In some cases, tetraoxanes and ozonides were more selective than paclitaxel, artemisinin, and artesunic acid. Annexin V flow‐cytometry analysis revealed that the active ozonides 22 a and 23 a induced cell death of HepG2 by apoptosis. Further study showed that compounds 22 a and 23 a exhibited a strong inhibitory effect on P‐glycoprotein (P‐gp/ABCB5)‐overexpressing HepG2 cancer cells. ABCB5 is a key player in the multidrug‐resistant phenotype of liver cancer. Peroxides failed to demonstrate a direct correlation between oxidative potential and their biological activity. To our knowledge this is the first time that peroxide diastereoisomers have been found to show stereospecific antimalarial action against the chloroquine‐sensitive 3D7 strain of Plasmodium falciparum . Stereoisomeric ozonide 12 b is 11 times more active than stereoisomeric ozonide 12 a (IC 50 =5.81 vs 65.18 μ m ). Current findings mean that ozonides merit further investigation as potential therapeutic agents for drug‐resistant hepatocellular carcinoma.
DOI: 10.1016/j.phrs.2021.105587
2021
Cited 26 times
Icariin enhances youth-like features by attenuating the declined gut microbiota in the aged mice
We previously reported the neuroprotective effects of icariin in rat cortical neurons. Here, we present a study on icariin's anti-aging effect in 24-month aged mice by treating them with a single daily dose of 100 mg/kg of icariin for 15 consecutive days. Icariin treatment improved motor coordination and learning skills while lowered oxidative stress biomarkers in the serum, brain, kidney, and liver of the aged mice. In addition, icariin improved the intestinal integrity of the aged mice by upregulating tight junction adhesion molecules and the Paneth and goblet cells, along with the reduction of iNOS and pro-inflammatory cytokines (IL-1β, TNF-α, IL-2 and IL-6, and IL-12). Icariin treatments also significantly upregulated aging-related signaling molecules, Sirt 1, 3 & 6, Pot1α, BUB1b, FOXO1, Ep300, ANXA3, Calb1, SNAP25, and BDNF in old mice. Through gut microbiota (GM) analysis, we observed icariin-associated improvements in GM composition of aged mice by reinstating bacteria found in the young mice, while suppressing some bacteria found in the untreated old mice. To clarify whether icariin's anti-aging effect is rooted in the GM, we performed fecal microbiota transfer (FMT) from icariin-treated old mice to the old mice. FMT-recipients exhibited similar improvements in the rotarod score and age-related biomarkers as observed in the icariin-treated old mice. Equal or better improvement on the youth-like features was noticed when aged mice were FMT with feces from young mice. Our study shows that both direct treatments with icariin and fecal transplant from the icariin-treated aged mice produce similar anti-aging phenotypes in the aged mice. We prove that GM plays a pivotal role in the healing abilities of icariin. Icariin has the potentials to be developed as a medicine for the wellness of the aged adults.
DOI: 10.1186/s41232-022-00209-7
2022
Cited 17 times
Targeting microglial autophagic degradation of the NLRP3 inflammasome for identification of thonningianin A in Alzheimer’s disease
NLRP3 inflammasome-mediated neuroinflammation plays a critical role in the pathogenesis and development of Alzheimer's disease (AD). Microglial autophagic degradation not only decreases the deposits of extracellular Aβ fibrils but also inhibits the activation of NRLP3 inflammasome. Here, we aimed to identify the potent autophagy enhancers from Penthorum chinense Pursh (PCP) that alleviate the pathology of AD via inhibiting the NLRP3 inflammasome.At first, autophagic activity-guided isolation was performed to identify the autophagy enhancers in PCP. Secondly, the autophagy effect was monitored by detecting LC3 protein expression using Western blotting and the average number of GFP-LC3 puncta per microglial cell using confocal microscopy. Then, the activation of NLRP3 inflammasome was measured by detecting the protein expression and transfected fluorescence intensity of NLRP3, ASC, and caspase-1, as well as the secretion of proinflammatory cytokines. Finally, the behavioral performance was evaluated by measuring the paralysis in C. elegans, and the cognitive function was tested by Morris water maze (MWM) in APP/PS1 mice.Four ellagitannin flavonoids, including pinocembrin-7-O-[4″,6″-hexahydroxydiphenoyl]-glucoside (PHG), pinocembrin-7-O-[3″-O-galloyl-4″,6″-hexahydroxydiphenoyl]-glucoside (PGHG), thonningianin A (TA), and thonningianin B (TB), were identified to be autophagy enhancers in PCP. Among these, TA exhibited the strongest autophagy induction effect, and the mechanistic study demonstrated that TA activated autophagy via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways. In addition, TA effectively promoted the autophagic degradation of NLRP3 inflammasome in Aβ(1-42)-induced microglial cells and ameliorated neuronal damage via autophagy induction. In vivo, TA activated autophagy and improved behavioral symptoms in C. elegans. Furthermore, TA might penetrate the blood-brain barrier and could improve cognitive function and ameliorate the Aβ pathology and the NLRP3 inflammasome-mediated neuroinflammation via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways in APP/PS1 mice.We identified TA as a potent microglial autophagy enhancer in PCP that promotes the autophagic degradation of the NLRP3 inflammasome to alleviate the pathology of AD via the AMPK/ULK1 and Raf/MEK/ERK signaling pathways, which provides novel insights for TA in the treatment of AD.
DOI: 10.1016/j.phrs.2022.106549
2022
Cited 15 times
The role of non-coding RNAs (miRNA and lncRNA) in the clinical management of rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder which is associated with the dysregulation of autoimmune response. In recent years, early diagnosis, aggressive treatment and alternative therapeutic options of disease-modifying anti-rheumatic drugs (DMARDs) markedly improve both the management and long-term prognosis of RA. Since the discovery of non-coding RNA (ncRNA) including microRNA (miRNA), long non-coding RNA (lncRNA) and others, their altered expressions have been unraveled to be deregulated in various diseases including RA. Several lines of evidence are emerging that ncRNA may contribute to the pathogenesis, disease progression and treatment of RA. For example, SNP rs2850711 within lnc00305 was indicated to associate with RA development susceptibility, whereas a higher level of miR-10a represented a good response to methotrexate (MTX) treatment in RA patients. In the aspect of refractory RA, ncRNA also plays an important role by affecting or regulating drug sensitivity in RA patients. Of note, lower expression of miR-20a in rheumatoid arthritis synovial fibroblast (RASFs) was demonstrated to activate the Janus Kinase (JAK)- signal transducer and activator of transcription 3(STAT3)-mediated inflammation, thereby promoting cell proliferation and apoptosis-resistant. In this review, we have illustrated the changes of ncRNAs and their underlying mechanisms in the whole developing period of RA pathogenesis and disease progression, as well as highlighted the novel therapeutic targets/strategies and bio-markers for RA therapy.
DOI: 10.1016/j.jff.2023.105962
2024
Melanogenic effects of 5-demethylnobiletin on mouse model of chemical-induced vitiligo
A phytochemical 5-demethylnobiletin from Citrus reticulata Blanco has a broad spectrum of pharmacological effects on anti-inflammatory, cardiovascular and neuroprotective effects, however, its in vivo effect on depigmentation remains unknown. To investigate how 5-demethylnobiletin regulates melanogenesis, both in vitro and in vivo experiments were conducted to evaluate its efficacy and mechanisms in human epidermal melanocyte and mice model of chemical-induced vitiligo. C57BL/6 mice were induced with 1% hydroquinone (HQ) to shaved dorsal skin and applied with 5-demethylnobiletin or 8-methoxypsoralen (8-MOP, positive control). Melanin contents measurement, immunohistochemistry, Fontana-Masson and HE histological analysis were used to determine melanin contents in follicles. q-PCR, Western blot, dichlorofluorescein (DCF) assay and computational docking were adopted to investigate the molecular mechanisms of 5-demethylnobiletin in the vitiligo mice model. Besides, acute dermal irritation test was conducted to evaluate the biological safety of 5-demethylnobiletin in mice. 5-demethylnobiletin possessed in vitro anti-oxidative effect, significantly increased melanin content in hair and ameliorated hypopigmentation in mice. The expression level of melanogenesis-related genes such as MITF, tyrosinase, Trp-1 and Trp-2 were significantly upregulated in 5-demethylnobiletin-treated groups. Molecular docking results support that 5-demethylnobiletin is able to bind to tyrosinase, the key enzyme for regulating melanogenesis, suggesting the potential molecular target of 5-demethylnobiletin. 5-demethylnobiletin has potential therapeutic effect on delaying the onset of depigmentation in vivo, lessened depigmentation incidence which contributes to melanogenesis. The newly revealed biological activity indicates 5-demethylnobiletin may be a potential natural pharmaceutical for the treatment and prevention of chemical-induced depigmentation disorders, and as the components for anti-gray hair products.
DOI: 10.1016/j.freeradbiomed.2019.10.417
2020
Cited 26 times
The active components derived from Penthorum chinense Pursh protect against oxidative-stress-induced vascular injury via autophagy induction
Oxidative stress-induced damage has been proposed as a major risk factor for cardiovascular disease and is a pathogenic feature of atherosclerosis. Although autophagy was reported to have a protective effect against atherosclerosis, its mechanism for reducing oxidative stress remains un-elucidated. In this study, we have identified 4 novel autophagic compounds from traditional Chinese medicines (TCMs), which activated the AMPK mediated autophagy pathway for the recovery of mitochondrial membrane potential (MMP) to reduce the production of reactive oxygen species (ROS) in Human umbilical vein endothelial cells (HUVECs). In this study, 4 compounds (TA, PG, TB and PG1) identified from Penthorum chinense Pursh (PCP) were demonstrated for the first time to possess binding affinity to HUVECs cell membranes via cell membrane chromatography (CMC) accompanied by UHPLC-TOF-MS analysis, and the 4 identified compounds induce autophagy in HUVECs. Among the 4 autophagic activators identified from PCP, TA (Thonningianin A, Pinocembrin dihydrochalcone-7-O-[3″-O-galloyl-4″,6″-hexahydroxydiphenoyl]-glucoside) is the major chemcial component in PCP, which possesses the most potent autophagy effect via a Ca2+/AMPK-dependent and mTOR-independent pathways. Moreover, TA efficiently reduced the level of ROS in HUVECs induced by H2O2. Additionally, the expression of pro- and cleaved-IL-1β in the aortic artery of ApoE-KO mice were also alleviated at the transcription and post-transcription levels after the administration of TA, which might be correlated to the reduction of oxidative-stress induced inflammasome-related Nod-like receptor protein3 (NLRP3) in the aortic arteries of ApoE-KO mice. This study has pinpointed the novel autophagic role of TA in alleviating the oxidative stress of HUVECs and aortic artery of ApoE-KO mice, and provided insight into the therapeutic application of TA in treatment of atherosclerosis or other cardiovascular diseases.
DOI: 10.1016/j.redox.2023.102637
2023
Cited 5 times
Hyperoside alleviates toxicity of β-amyloid via endoplasmic reticulum-mitochondrial calcium signal transduction cascade in APP/PS1 double transgenic Alzheimer's disease mice
Alzheimer's disease is a neurodegenerative disorder characterized by a decline in cognitive function. The β-amyloid (Aβ) hypothesis suggests that Aβ peptides can spontaneously aggregate into β-fragment-containing oligomers and protofibrils, and this activation of the amyloid pathway alters Ca2+ signaling in neurons, leading to neurotoxicity and thus apoptosis of neuronal cells. In our study, a blood-brain barrier crossing flavonol glycoside hyperoside was identified with anti-Aβ aggregation, BACE inhibitory, and neuroprotective effect in cellular or APP/PSEN1 double transgenic Alzheimer's disease mice model. While our pharmacokinetic data confirmed that intranasal administration of hyperoside resulted in a higher bio-availability in mice brain, further in vivo studies revealed that it improved motor deficit, spatial memory and learning ability of APP/PSEN1 mice with reducing level of Aβ plaques and GFAP in the cortex and hippocampus. Bioinformatics, computational docking and in vitro assay results suggested that hyperoside bind to Aβ and interacted with ryanodine receptors, then regulated cellular apoptosis via endoplasmic reticulum-mitochondrial calcium (Ca2+) signaling pathway. Consistently, it was confirmed that hyperoside increased Bcl2, decreased Bax and cyto-c protein levels, and ameliorated neuronal cell death in both in vitro and in vivo model. By regulating Aβ-induced cell death via regulation on Ca2+ signaling cascade and mitochondrial membrane potential, our study suggested that hyperoside may work as a potential therapeutic agent or preventive remedy for Alzheimer's disease.
DOI: 10.1016/j.phymed.2010.06.012
2010
Cited 39 times
Total ginsenosides increase coronary perfusion flow in isolated rat hearts through activation of PI3K/Akt-eNOS signaling
Ginseng is the most popular herb used for treatment of ischemic heart diseases in Chinese community; ginsenosides are considered to be the major active ingredients. However, whether ginsenosides can enhance the coronary artery flow of ischemic heart and, if so, by what mechanisms they do this, remains unclear. Isolated rat hearts with ischemia/reperfusion injury in Langendorff system were employed for examining the effect of total ginsenosides (TGS) on coronary perfusion flow (CPF). In addition, human aortic endothelial cells (HAECs) were used for mechanistic study. Levels of various vasodilative molecules, intracellular calcium concentration ([Ca2+]i), and expressions and activation of proteins involving regulation of nitric oxide (NO) signaling pathways in heart tissues and HAECs were determined. TGS dose-dependently and significantly increased CPF and improved systolic and diastolic function of the ischemia/reperfused rat heart, while inhibitors of NO synthase (NOS), soluble guanylate cyclase (sGC), heme oxygenase (HO), cyclooxygenase (COX), and potassium channel abolished the vasodilation effect of TGS. Positive control verapamil was effective only in increasing CPF. TGS elevated levels of NO and 6-keto-prostaglandin F1α, a stable hydrolytic product of prostacyclin I2 (PGI2), in both coronary effluents and supernatants of HAECs culturing medium, and augmented [Ca2+]i in HAECs. TGS significantly up-regulated expression of phosphoinositide 3-kinase (PI3K) and phosphorylations of Akt and endothelial NOS (eNOS) as well. TGS significantly increased CPF of ischemia/reperfused rat hearts through elevation of NO production via activation of PI3K/Akt-eNOS signaling. In addition, PGI2, EDHF and CO pathways also partially participated in vasodilation induced by TGS.
DOI: 10.18632/oncotarget.18991
2017
Cited 30 times
New perspectives of cobalt tris(bipyridine) system: anti-cancer effect and its collateral sensitivity towards multidrug-resistant (MDR) cancers
Platinating compounds including cisplatin, carboplatin, and oxaliplatin are common chemotherapeutic agents, however, patients developed resistance to these clinical agents after initial therapeutic treatments.Therefore, different approaches have been applied to identify novel therapeutic agents, molecular mechanisms, and targets for overcoming drug resistance.In this study, we have identified a panel of cobalt complexes that were able to specifically induce collateral sensitivity in taxol-resistant and p53-deficient cancer cells.Consistently, our reported anti-cancer functions of cobalt complexes 1-6 towards multidrug-resistant cancers have suggested the protective and non-toxic properties of cobalt metal-ions based compounds in anti-cancer therapies.As demonstrated in xenograft mouse model, our results also confirmed the identified cobalt complex 2 was able to suppress tumor growth in vivo.The anti-cancer effect of the cobalt complex 2 was further demonstrated to be exerted via the induction of autophagy, cell cycle arrest, and inhibition of cell invasion and P-glycoprotein (P-gp) activity.These data have provided alternative metal ion compounds for targeting drug resistance cancers in chemotherapies.
DOI: 10.3389/fphar.2019.01427
2019
Cited 27 times
Bavachin Protects Human Aortic Smooth Muscle Cells Against β-Glycerophosphate-Mediated Vascular Calcification and Apoptosis via Activation of mTOR-Dependent Autophagy and Suppression of β-Catenin Signaling
Vascular calcification is a major complication of cardiovascular disease and chronic renal failure. Autophagy help to maintain a stable internal and external environment that is important for modulating arteriosclerosis, but its underlying mechanism is still unclear. In this study, we aimed to identify the bioactive compounds from traditional Chinese medicines (TCM) that exhibit an anti-arteriosclerosis effect. In β-glycerophosphate (β-GP)-stimulated human aortic smooth muscle cells (HASMCs), the calcium level was increased and the expression of the calcification-related proteins OPG, OPN, Runx2, and BMP2 were all up-regulated, followed by autophagy induction and apoptosis. Meanwhile, we further revealed that β-GP induced apoptosis and promoted osteogenic differentiation of human osteoblastic cells via Wnt/β-Catenin signaling. Bavachin, a natural compound from Psoralea corylifolia, dose-dependently reduced the level of intracellular calcium and the expression of calcification-related proteins OPG, OPN, Runx2 and BMP2, thus inhibiting cell apoptosis. In addition, Bavachin increased LC3-II and beclin1 expression, along with intracellular LC3-II puncta formation, which autophagy induction is Atg7-dependent and is regulated by suppression of mTOR signaling. Furthermore, addition of autophagy inhibitor, wortmannin (WM) attenuated the inhibitory effect of Bavachin on β-GP-induced calcification and apoptosis in HASMCs. Collectively, the present study revealed that Bavachin protects HASMCs against apoptosis and calcification by activation of the Atg7/mTOR‐autophagy pathway and suppression of the Wnt/β-catenin signaling, our findings provide a potential clinical application for Bavachin in the therapy of cardiovascular disease.
DOI: 10.1016/j.bioorg.2019.03.034
2019
Cited 25 times
Semi-synthetic isoflavones as BACE-1 inhibitors against Alzheimer’s disease
BACE-1 is considered to be one of the targets for prevention and treatment of Alzheimer’s disease (AD). We here report a novel class of semi-synthetic derivatives of prenylated isoflavones, obtained from the derivatization of natural flavonoids from Maclura pomifera. In vitro anti-AD effect of the synthesized compounds were evaluated via human recombinant BACE-1 inhibition assay. Compound 7, 8 and 13 were found to be the most active candidates which demonstrates good correlation between the computational docking and pharmacokinetic predictions. Moreover, cytotoxic studies demonstrated that the compounds are not toxic against normal and cancer cell lines. Among these three compounds, compound 7 enhance the activity of P-glycoprotein (P-gp) on A549 cancer cells and increases the activity of P-gp ATPase with a possible role on the efflux of amyloid-β across the blood- brain barrier. In conclusion, the present findings may pave the way for the discovery of a novel class of compounds to prevent and/or treat AD.
DOI: 10.1016/j.coph.2020.08.002
2020
Cited 21 times
Drug-resistance in rheumatoid arthritis: the role of p53 gene mutations, ABC family transporters and personal factors
Rheumatoid arthritis (RA) is an autoimmune disease that is associated with chronic inflammation in joints, which contribute to synovial membrane hyperplasia and cartilage damage. Conventional disease-modifying antirheumatic drugs (DMARDs), such as methotrexate (MTX) and leflunomide (LEF), are the common RA therapy to reduce inflammation and disease progression. Recently, drug-resistance in RA with conventional treatment has become an issue. Mutations in p53 tumor suppressor gene and overexpression of ABCB1/MDR-1/P-gp transporters may contribute to antirheumatic drug-resistance in RA. Biologic DMARDs (bDMARDs) are often prescribed, when conventional DMARDs fail to treat RA, by targeting proinflammatory mediators such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-6. The efficacy of bDMARDs is affected by personal factors, for example, age, smoking, body mass index (BMI), immunogenicity, and genetic polymorphisms. This review highlights the role of p53 gene mutations, ABC family transporters and personal factors in antirheumatic drug-resistance, which may lead to new personalized therapies against RA with an increased drug-sensitivity.
DOI: 10.1186/s13020-022-00667-8
2022
Cited 11 times
Poria cocos polysaccharides exert prebiotic function to attenuate the adverse effects and improve the therapeutic outcome of 5-FU in ApcMin/+ mice
As a first-line chemotherapeutic agent, 5-fluorouracil (5-FU) exhibits many side effects, weakening its efficacy in cancer treatment. In this study, we hypothesize that Poria cocos polysaccharides (PCP), a traditional Chinese herbal medicine with various bioactivities and prebiotic effects, might improve the therapeutic effect of 5-FU by restoring the homeostasis of the gut microenvironment and the commensal gut microflora.ApcMin/+ mice were employed to evaluate the anti-cancer effect of 5-FU in conjunction with PCP treatment. Body weight and food consumption were monitored weekly. Polyp count was used to assess the anti-cancer effect of PCP and 5-FU. Expressions of mucosal cytokines and gut epithelial junction molecules were measured using qRT-PCR. 16S rRNA gene sequencing of fecal DNAs was used to evaluate the compositional changes of gut microbiota (GM). Transplantation of Lactobacillus johnsonii and Bifidobacterium animalis were performed to verify the prebiotic effects of PCP in improving the efficacy of 5-FU.The results showed that PCP treatment alleviated the weight loss caused by 5-FU treatment and reduced the polyp burden in ApcMin/+ mice. Additionally, PCP treatment eased the cytotoxic effects of 5-FU by reducing the expressions of pro-inflammatory cytokines, increasing the anti-inflammatory cytokines; and significantly improving the gut barriers by enhancing the tight junction proteins and associated adhesion molecules. Furthermore, 16S rRNA gene sequencing data showed that PCP alone or with 5-FU could stimulate the growth of probiotic bacteria (Bacteroides acidifaciens, Bacteroides intestinihominis, Butyricicoccus pullicaecorum, and the genera Lactobacillus, Bifidobacterium, Eubacterium). At the same time, it inhibited the growth of potential pathogens (e.g., Alistipes finegoldii, Alistipes massiliensis, Alistipes putredinis., Citrobacter spp., Desulfovibrio spp., and Desulfovibrio desulfuricans). Moreover, the results showed that transplantation of L.johnsonii and B.animalis effectively reduced the polyp burden in ApcMin/+ mice being treated with 5-FU.Our study showed that PCP could effectively improve the anti-cancer effect of 5-FU by attenuating its side effects, modulating intestinal inflammation, improving the gut epithelial barrier, and modulating the gut microbiota of ApcMin/+ mice.
DOI: 10.1016/j.phymed.2021.153826
2022
Cited 10 times
Nimbolide inhibits 2D and 3D prostate cancer cells migration, affects microtubules and angiogenesis and suppresses B-RAF/p.ERK-mediated in vivo tumor growth
Prostate cancer (PCa) is the most prominent malignancy among men worldwide. PCa cells have a high tendency to metastasize to various distant organs, and this activity is the main cause of PCa mortality. Nimbolide is a promising phytochemical constituent of neem Azadirachta indica (Meliaceae). Previous studies showed that nimbolide exhibited potent anticancer activity however, its role against PCa tumorigenesis has not been fully elucidated.Our work aims to explore the role of nimbolide in regulating the essential tumor-associated processes involved in the metastatic cascade in PCa cells.Cytotoxicity assay, wound healing and spheroid invasion assays, western blotting, immunofluorescence, tube-formation assay, in vivo and immunohistochemistry.The cytotoxicity of nimbolide towards PCa cell lines was assessed by resazurin assays. The cell mobility and migration of nimbolide-treated DU145 cells were determined by wound healing and spheroid invasion assays. Tubulin network was visualized using U2OS cells and DU145 cells. The effect of nimbolide on E-cadherin, β-catenin, acetylated α-tubulin and HDAC6 protein expressions levels were measured by Western blot. The potentiality of nimbolide to inhibit angiogenesis was revealed by HUVEC tube-formation assay. Nimbolide antitumor effect was studied in a syngeneic model of murine prostate cancer.The current study indicated that nimbolide negatively affected the migratory and invasive capacity of DU145 prostate cancer cells in 2D and three-dimensional (3D) spheroid cultures. Interestingly, nimbolide induced downregulation of E-cadherin without any influence on the expression level of β-catenin. Additionally, we demonstrated that nimbolide influenced the microtubule network which was supported by the upregulation of acetylated α-tubulin and the reduction in HDAC6 protein. Moreover, the inhibitory effect of nimbolide on angiogenesis was clearly observed in HUVEC tube formation assay. In vivo experiments revealed the significant suppression of PCa growth and targeting of the B-RAF/p.ERK signaling pathway by nimbolide.Our results showed that nimbolide inhibited 2D and 3D prostate cancer cells migration and downregulated E-cadherin protein expression, a marker for metastatic chemoresistance and tumor recurrence. Nimbolide stabilized the microtubules, combated angiogenesis and suppressed B.RAF/ERK-mediated in vivo tumor growth. Nimbolide may be considered as potential therapeutic agent for metastatic and advanced PCa patients and merits further investigations.
DOI: 10.1002/jev2.12279
2022
Cited 10 times
Suppression of PD‐L1 release from small extracellular vesicles promotes systemic anti‐tumor immunity by targeting ORAI1 calcium channels
Blockade of immune checkpoints as a strategy of cancer cells to overcome the immune response has received ample attention in cancer research recently. In particular, expression of PD-L1 by various cancer cells has become a paradigm in this respect. Delivery of PD-L1 to its site of action occurs either by local diffusion, or else by transport via small extracellular vesicles (sEVs, commonly referred to as exosomes). Many steps of sEVs formation, their packaging with PD-L1 and their release into the extracellular space have been studied in detail. The likely dependence of release on Ca2+ -signaling, however, has received little attention. This is surprising, since the intracellular Ca2+ -concentration is known as a prominent regulator of many secretory processes. Here, we report on the roles of three Ca2+ -dependent proteins in regulating release of PD-L1-containing sEVs, as well as on the growth of tumors in mouse models. We show that sEVs release in cancer cell lines is Ca2+ -dependent and the knockdown of the gene coding the Ca2+ -channel protein ORAI1 reduces Ca2+ -signals and release of sEVs. Consequently, the T cell response is reinvigorated and tumor progression in mouse models is retarded. Furthermore, analysis of protein expression patterns in samples from human cancer tissue shows that the ORAI1 gene is significantly upregulated. Such upregulation is identified as an unfavorable prognostic factor for survival of patients with non-small-cell lung cancer. We show that reduced Ca2+ -signaling after knockdown of ORAI1 gene also compromises the activity of melanophilin and Synaptotagmin-like protein 2, two proteins, which are important for correct localization of secretory organelles within cancer cells and their transport to sites of exocytosis. Thus, the Ca2+ -channel ORAI1 and Ca2+ -dependent proteins of the secretion pathway emerge as important targets for understanding and manipulating immune checkpoint blockade by PD-L1.
DOI: 10.3389/fbioe.2023.1150290
2023
Cited 4 times
External stimulation: A potential therapeutic strategy for tendon-bone healing
Injuries at the tendon-bone interface are very common in the field of sports medicine, and healing at the tendon-bone interface is complex. Injuries to the tendon-bone interface can seriously affect a patient's quality of life, so it is essential to restore stability and promote healing of the tendon-bone interface. In addition to surgical treatment, the healing of tendons and bones can also be properly combined with extracorporeal stimulation therapy during the recovery process. In this review, we discuss the effects of extracorporeal shock waves (ESWs), low-intensity pulsed ultrasound (LIPUS), and mechanical stress on tendon-bone healing, focusing on the possible mechanisms of action of mechanical stress on tendon-bone healing in terms of transcription factors and biomolecules. The aim is to provide possible therapeutic approaches for subsequent clinical treatment.
DOI: 10.1016/j.phrs.2023.106769
2023
Cited 4 times
Pomiferin targets SERCA, mTOR, and P-gp to induce autophagic cell death in apoptosis-resistant cancer cells, and reverses the MDR phenotype in cisplatin-resistant tumors in vivo
Drug resistance in cancer has been classified as innate resistance or acquired resistance, which were characterized by apoptotic defects and ABC transporters overexpression respectively. Therefore, to preclude or reverse these resistance mechanisms could be a promising strategy to improve chemotherapeutic outcomes. In this study, a natural product from Osage Orange, pomiferin, was identified as a novel autophagy activator that circumvents innate resistance by triggering autophagic cell death via SERCA inhibition and activation of the CaMKKβ-AMPK-mTOR signaling cascade. In addition, pomiferin also directly inhibited the P-gp (MDR1/ABCB1) efflux and reversed acquired resistance by potentiating the accumulation and efficacy of the chemotherapeutic agent, cisplatin. In vivo study demonstrated that pomiferin triggered calcium-mediated tumor suppression and exhibited an anti-metastatic effect in the LLC-1 lung cancer-bearing mouse model. Moreover, as an adjuvant, pomiferin potentiated the anti-tumor effect of the chemotherapeutic agent, cisplatin, in RM-1 drug-resistant prostate cancer-bearing mouse model by specially attenuating ABCB1-mediated drug efflux, but not ABCC5, thereby promoting the accumulation of cisplatin in tumors. Collectively, pomiferin may serve as a novel effective agent for circumventing drug resistance in clinical applications.
DOI: 10.1016/j.jpha.2023.04.010
2023
Cited 4 times
A robust luminescent assay for screening alkyladenine DNA glycosylase inhibitors to overcome DNA repair and temozolomide drug resistance
Temozolomide (TMZ) is an anticancer agent used to treat glioblastoma, typically following radiation therapy and/or surgical resection. However, despite its effectiveness, at least 50% of patients do not respond to TMZ, which is associated with repair and/or tolerance of TMZ-induced DNA lesions. Studies have demonstrated that alkyladenine DNA glycosylase (AAG), an enzyme that triggers the base excision repair (BER) pathway by excising TMZ-induced N3-methyladenine (3meA) and N7-methylguanine lesions, is overexpressed in glioblastoma tissues compared to normal tissues. Therefore, it is essential to develop a rapid and efficient screening method for AAG inhibitors to overcome TMZ resistance in glioblastomas. Herein, we report a robust time-resolved photoluminescence platform for identifying AAG inhibitors with improved sensitivity compared to conventional steady-state spectroscopic methods. As a proof-of-concept, this assay was used to screen 1440 food and drug administration-approved drugs against AAG, resulting in the repurposing of sunitinib as a potential AAG inhibitor. Sunitinib restored glioblastoma (GBM) cancer cell sensitivity to TMZ, inhibited GBM cell proliferation and stem cell characteristics, and induced GBM cell cycle arrest. Overall, this strategy offers a new method for the rapid identification of small-molecule inhibitors of BER enzyme activities that can prevent false negatives due to a fluorescent background.
DOI: 10.3892/ijo.2016.3644
2016
Cited 25 times
Autophagic degradation of epidermal growth factor receptor in gefitinib-resistant lung cancer by celastrol
Drug resistance of non-small cell lung cancer (NSCLC) is highly correlated to the mutation of the epidermal growth factor receptor (EGFR). Although EGFR tyrosine kinase inhibitors (TKIs) are available clinically, the molecular complexity of NSCLC has made it necessary to search for alternative therapeutic approaches to overcome the drug resistance of NSCLC. In the present study, we identified a triterpene molecule derived from the herbal plant Tripterygium wilfordii, celastrol, as a novel autophagy inducer. We demonstrate that celastrol exhibited selective cytotoxic effect towards EGFR mutant NSCLCs. In addition, celastrol also facilitated the autophagic degradation of Hsp90 client protein including EGFR and Akt on both EGFR wild-type and mutant NSCLCs via calcium-mediated autophagy. Blockage of celastrol-induced autophagic degradation of EGFR by autophagic inhibitor or calcium chelator decreased celastrol-mediated cell death in gefitinib-resistant NSCLCs. Overall, our findings suggest that celastrol may be developed as an effective anticancer agent for treatment of gefitinib-resistant NSCLC in the future.
DOI: 10.1016/j.canlet.2020.03.028
2020
Cited 18 times
Overexpression of ubiquitin-conjugating enzyme E2 L3 in hepatocellular carcinoma potentiates apoptosis evasion by inhibiting the GSK3β/p65 pathway
UBE2L3 is a ubiquitin-conjugating protein belonging to the E2 family that consists of 153 amino acid residues. In this study, we found that UBE2L3 was generally upregulated in clinical HCC samples compared to non-tumour samples and that there was a strong association between high UBE2L3 expression and tumour size, clinical grade and prognosis in HCC patients. UBE2L3 depletion inhibited the proliferation and induced the apoptosis of HCC cells. At the molecular level, we observed that UBE2L3 depletion enhanced the protein stability of GSK3β, thus promoting the expression and activation of GSK3β. Subsequently, activated GSK3β phosphorylated p65 and promoted its nuclear translocation to increase the expression of target genes, including PUMA, Bax, Bim, Bad, and Bid. In vivo, knockout of UBE2L3 in HCC cells inhibited tumour growth in orthotopic liver injection nude mouse models. Moreover, inhibition of p65 or GSK3β significantly restored the effects induced by UBE2L3 knockout in HCC. Together, this study reveals the stimulatory effect of UBE2L3 on HCC cell proliferation, suggesting that UBE2L3 may be an important pro-tumorigenic factor in liver carcinogenesis and a potential therapeutic target of HCC.
DOI: 10.1002/cmdc.202000045
2020
Cited 18 times
Design, Synthesis, Structure‐Activity Relationship and Docking Studies of Novel Functionalized Arylvinyl‐1,2,4‐Trioxanes as Potent Antiplasmodial as well as Anticancer Agents
Abstract A novel series of synthetic functionalized arylvinyl‐1,2,4‐trioxanes ( 8 a – p ) has been prepared and assessed for their in vitro antiplasmodial activity against the chloroquine‐resistant Pf INDO strain of Plasmodium falciparum by using a SYBR green‐I fluorescence assay. Compounds 8 g (IC 50 =0.051 μM; SI=589.41) and 8 m (IC 50 =0.059 μM; SI=55.93) showed 11‐fold and &gt;9‐fold more potent antiplasmodial activity, respectively, as compared to chloroquine (IC 50 =0.546 μM; SI=36.63). Different in silico docking studies performed on many target proteins revealed that the most active arylvinyl‐1,2,4‐trioxanes ( 8 g and 8 m ) showed dihydrofolate reductase (DHFR) binding affinities on a par with those of chloroquine and artesunate. The in vitro cytotoxic potentials of 8 a – p were also evaluated against human lung (A549) and liver (HepG2) cancer cell lines along with immortalized normal lung (BEAS‐2B) and liver (LO2) cell lines. Following screening, five derivatives viz. 8 a , 8 h , 8 l , 8 m and 8 o (IC 50 =1.65–31.7 μM; SI=1.08–10.96) were found to show potent cytotoxic activity against (A549) lung cancer cell lines, with selectivity superior to that of the reference compounds artemisinin (IC 50 =100 μM), chloroquine (IC 50 =100 μM) and artesunic acid (IC 50 =9.85 μM; SI=0.76). In fact, the most active 4‐naphthyl‐substituted analogue 8 l (IC 50 =1.65 μM; SI &gt;10) exhibited &gt;60 times more cytotoxicity than the standard reference, artemisinin, against A549 lung cancer cell lines. In silico docking studies of the most active anticancer compounds, 8 l and 8 m , against EGFR were found to validate the wet lab results. In summary, a new series of functionalized aryl‐vinyl‐1,2,4‐trioxanes ( 8 a – p ) has been shown to display dual potency as promising antiplasmodial and anticancer agents.
DOI: 10.3390/ph14100954
2021
Cited 16 times
A Drug Repurposing Approach for Antimalarials Interfering with SARS-CoV-2 Spike Protein Receptor Binding Domain (RBD) and Human Angiotensin-Converting Enzyme 2 (ACE2)
Host cell invasion by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is mediated by the interaction of the viral spike protein (S) with human angiotensin-converting enzyme 2 (ACE2) through the receptor-binding domain (RBD). In this work, computational and experimental techniques were combined to screen antimalarial compounds from different chemical classes, with the aim of identifying small molecules interfering with the RBD-ACE2 interaction and, consequently, with cell invasion. Docking studies showed that the compounds interfere with the same region of the RBD, but different interaction patterns were noted for ACE2. Virtual screening indicated pyronaridine as the most promising RBD and ACE2 ligand, and molecular dynamics simulations confirmed the stability of the predicted complex with the RBD. Bio-layer interferometry showed that artemisone and methylene blue have a strong binding affinity for RBD (KD = 0.363 and 0.226 μM). Pyronaridine also binds RBD and ACE2 in vitro (KD = 56.8 and 51.3 μM). Overall, these three compounds inhibit the binding of RBD to ACE2 in the μM range, supporting the in silico data.
DOI: 10.1016/j.ejmech.2021.113676
2021
Cited 15 times
Synthesis, computational docking and biological evaluation of celastrol derivatives as dual inhibitors of SERCA and P-glycoprotein in cancer therapy
A series of eleven celastrol derivatives was designed, synthesized, and evaluated for their in vitro cytotoxic activities against six human cancer cell lines (A549, HepG2, HepAD38, PC3, DLD-1 Bax-Bak WT and DKO) and three human normal cells (LO2, BEAS-2B, CCD19Lu). To our knowledge, six derivatives were the first example of dipeptide celastrol derivatives. Among them, compound 3 was the most promising derivative, as it exhibited a remarkable anti-proliferative activity and improved selectivity in liver cancer HepAD38 versus human normal hepatocytes, LO2. Compound 6 showed higher selectivity in liver cancer cells against human normal lung fibroblasts, CCD19Lu cell line. The Ca2+ mobilizations of 3 and 6 were also evaluated in the presence and absence of thapsigargin to demonstrate their inhibitory effects on SERCA. Derivatives 3 and 6 were found to induce apoptosis on LO2, HepG2 and HepAD38 cells. The potential docking poses of all synthesized celastrol dipeptides and other known inhibitors were proposed by molecular docking. Finally, 3 inhibited P-gp-mediated drug efflux with greater efficiency than inhibitor verapamil in A549 lung cancer cells. Therefore, celastrol-dipeptide derivatives are potent drug candidates for the treatment of drug-resistant cancer.
DOI: 10.1016/j.gendis.2023.01.034
2023
Cited 3 times
Development of a dual targeting scaffold of SET7/MLL inhibitor for castration-resistant prostate cancer treatment
DOI: 10.1016/j.molstruc.2023.135707
2023
Cited 3 times
Artemisinin-inspired novel functionalized aryloxy-arylvinyl-1,2,4-trioxanes as potent anticancer agents: Design, synthesis, bioevaluation, SAR and in silico studies
Herein, a range of substituted aryloxy-arylvinyl-1,2,4-trioxanes (8a-8i), inspired from naturally occurring artemisinin, has been synthesized and then evaluated for their in vitro anticancer activity against human lung (A549) and liver (HepG2) cancer cell lines along with immortalized normal lung (BEAS-2B) and liver (LO2) cell lines. Out of the 34 synthesized aryloxy-arylvinyl-1,2,4-trioxanes, six compounds (8b2, 8d1, 8f2, 8f3, 8g1, 8h1) (IC50=11-37.73 µM; SI=1.7-9.6) displays promising in vitro anticancer activity. While these six compounds were proven to be more efficient and selective than those of reference standards such as artemisinin (IC50 = 100 µM) and chloroquine (IC50 = 100 µM), at the same time these were showing comparable in vitro anticancer activity with respect to one of standard reference compound artesunic acid (IC50 = 9.85 µM; SI = 0.76) against (A549) lung cancer cell line. Compound 8d1 from the series of synthesized aryloxy-arylvinyl-1,2,4-trioxanes was found out to be equipotent (IC50 = 11 µM; SI > 9) with respect to standard reference compound artesunic acid and likewise compound 8g1 (IC50 = 17.7 µM; SI > 2.4) also showed promising anticancer activity. In silico molecular docking studies of potent aryloxy-arylvinyl-1,2,4-trioxanes (8d1 & 8g1) along with standard drug molecules against the epidermal growth factor receptor (EGFR; PDB ID: 1M17) revealed a strong virtual interaction.
DOI: 10.1002/cmdc.200700065
2007
Cited 33 times
Preparation of <i>N</i>‐Sulfonyl‐ and <i>N</i>‐Carbonyl‐11‐Azaartemisinins with Greatly Enhanced Thermal Stabilities: in vitro Antimalarial Activities
As the clinically used artemisinins do not withstand the thermal stress testing required to evaluate shelf life for storage in tropical countries where malaria is prevalent, there is a need to develop thermally more robust artemisinin derivatives. Herein we describe the attachment of electron-withdrawing arene- and alkanesulfonyl and -carbonyl groups to the nitrogen atom of the readily accessible Ziffer 11-azaartemisinin to provide the corresponding N-sulfonyl- and -carbonylazaartemisinins. Two acylurea analogues were also prepared by treatment of the 11-azaartemisinin with arylisocyanates. Several of the N-sulfonylazaartemisinins have melting points above 200 degrees C and possess substantially greater thermal stabilities than the artemisinins in current clinical use, with the antimalarial activities of several of the arylsulfonyl derivatives being similar to that of artesunate against the drug-sensitive 3D7 clone of the NF54 isolate and the multidrug-resistant K1 strain of P. falciparum. The compounds possess relatively low cytotoxicities. The carbonyl derivatives are less crystalline than the N-sulfonyl derivatives, but are generally more active as antimalarials. The N-nitroarylcarbonyl and arylurea derivatives possess sub-ng ml(-1) activities. Although several of the azaartemisinins possess log P values below 3.5, the compounds have poor aqueous solubility (<1 mg L(-1) at pH 7). The greatly enhanced thermal stability of our artemisinins suggests that strategic incorporation of electron-withdrawing polar groups into both new artemisinin derivatives and totally synthetic trioxanes or trioxolanes may assist in the generation of practical new antimalarial drugs which will be stable to storage conditions in the field, while retaining favorable physicochemical properties.
DOI: 10.1002/jcb.22230
2009
Cited 30 times
Pseudolaric acid B suppresses T lymphocyte activation through inhibition of NF‐κB signaling pathway and p38 phosphorylation
Pseudolaric acid B (PAB) is a major bioactive component of the medicinal plant Pseudolarix kaempferi. Traditional medicine practitioners in Asia have been using the roots of this plant to treat inflammatory and microbial skin diseases for centuries. In the current study, in vitro immunosuppressive effect of PAB and the underlying mechanisms have been investigated. The results showed that PAB dose-dependently suppressed human T lymphocyte proliferation, IL-2 production and CD25 expression induced by co-stimulation of PMA plus ionomycin or of anti-OKT-3 plus anti-CD28. Mechanistic studies showed that PAB significantly inhibited nuclear translocation of NF-kappaB p65 and phosphorylation and degradation of IkappaB-alpha evoked by co-stimulation of PMA plus ionomycin. PAB could also suppress the phosphorylation of p38 in the MAPKs pathway. Based on these evidences, we conclude that PAB suppressed T lymphocyte activation through inhibition of NF-kappaB and p38 signaling pathways; this would make PAB a strong candidate for further study as an anti-inflammatory agent.
DOI: 10.1248/bpb.33.40
2010
Cited 28 times
Matrine Induces Cell Anergy in Human Jurkat T Cells through Modulation of Mitogen-Activated Protein Kinases and Nuclear Factor of Activated T-Cells Signaling with Concomitant Up-Regulation of Anergy-Associated Genes Expression
Induction of immunotolerance has become a new strategy for treating autoimmune conditions in recent decades. However, so far there is no ideal therapeutics available for clinical use. Medicinal herbs are a promising potential source of immunotolerance inducers. In the current study, we sought first to optimize conditions for a validated cellular model of human Jurkat cells; and then used this model to screen bioactive compounds derived from medicinal plants for inducing T cell anergy in comparison with the effect of well-known T cell anergy inducer, ionomycin. The results showed that passage of the cells, and concentration and stimulation time of ionomycin on the cells could influence the ability of T cell anergy induction. Matrine, a small molecule derived from the root of Sophora flavescens AIT., was demonstrated to be effective in inducing T cell anergy in human Jurkat cells. The cells exposed to matrine showed markedly decreased mRNA expression of interleukin-2, an indicator of T cell anergy, when the cells were stimulated by antigens, anti-OKT3 plus anti-CD28. Mechanistic study showed that ionomycin and matrine could up-regulate the anergy-associated gene expressions of CD98 and Jumonji and activate nuclear factor of activated T-cells (NFAT) nuclear translocation in absence of cooperation of AP-1 in Jurkat cells. Pre-incubation with matrine or ionomycin could also shorten extracellular signal-regulated kinase (ERK) and suppress c-Jun NH(2)-terminal kinase (JNK) expression on the anergic Jurkat cells when the cells were stimulated with anti-OKT-3 plus anti-CD28 antibodies. Thus, matrine is a strong candidate for further investigation as a T cell immunotolerance inducer.
DOI: 10.18632/oncotarget.5567
2015
Cited 22 times
Mutation of cysteine 46 in IKK-beta increases inflammatory responses
Activation of IκB kinase β (IKK-β) and nuclear factor (NF)-κB signaling contributes to cancer pathogenesis and inflammatory disease; therefore, the IKK-β-NF-κB signaling pathway is a potential therapeutic target. Current drug design strategies focus on blocking NF-κB signaling by binding to specific cysteine residues on IKK-β. However, mutations in IKK-β have been found in patients who may eventually develop drug resistance. For these patients, a new generation of IKK-β inhibitors are required to provide novel treatment options. We demonstrate in vitro that cysteine-46 (Cys-46) is an essential residue for IKK-β kinase activity. We then validate the role of Cys-46 in the pathogenesis of inflammation using delayed-type hypersensitivity (DTH) and an IKK-β C46A transgenic mouse model. We show that a novel IKK-β inhibitor, dihydromyricetin (DMY), has anti-inflammatory effects on WT DTH mice but not IKK-β C46A transgenic mice. These findings reveal the role of Cys-46 in the promotion of inflammatory responses, and suggest that Cys-46 is a novel drug-binding site for the inhibition of IKK-β.
DOI: 10.1002/ange.201807305
2018
Cited 19 times
Selective Inhibition of Lysine‐Specific Demethylase 5A (KDM5A) Using a Rhodium(III) Complex for Triple‐Negative Breast Cancer Therapy
Abstract Lysine‐specific demethylase 5A (KDM5A) has recently become a promising target for epigenetic therapy. In this study, we designed and synthesized metal complexes bearing ligands with reported demethylase and p27 modulating activities. The Rh(III) complex 1 was identified as a direct, selective and potent inhibitor of KDM5A that directly abrogate KDM5A demethylase activity via antagonizing the KDM5A‐tri‐/di‐methylated histone 3 protein–protein interaction (PPI) in vitro and in cellulo. Complex 1 induced accumulation of H3K4me3 and H3K4me2 levels in cells, causing growth arrest at G1 phase in the triple‐negative breast cancer (TNBC) cell lines, MDA‐MB‐231 and 4T1. Finally, 1 exhibited potent anti‐tumor activity against TNBC xenografts in an in vivo mouse model, presumably via targeting of KDM5A and hence upregulating p27. Moreover, complex 1 was less toxic compared with two clinical drugs, cisplatin and doxorubicin. To our knowledge, complex 1 is the first metal‐based KDM5A inhibitor reported in the literature. We anticipate that complex 1 may be used as a novel scaffold for the further development of more potent epigenetic agents against cancers, including TNBC.
DOI: 10.1038/s41419-020-02881-4
2020
Cited 17 times
Novel ginsenoside derivative 20(S)-Rh2E2 suppresses tumor growth and metastasis in vivo and in vitro via intervention of cancer cell energy metabolism
Abstract Increased energy metabolism is responsible for supporting the abnormally upregulated proliferation and biosynthesis of cancer cells. The key cellular energy sensor AMP-activated protein kinase (AMPK) and the glycolytic enzyme alpha-enolase (α-enolase) have been identified as the targets for active components of ginseng. Accordingly, ginseng or ginsenosides have been demonstrated with their potential values for the treatment and/or prevention of cancer via the regulation of energy balance. Notably, our previous study demonstrated that the R -form derivative of 20( R )-Rh2, 20( R )-Rh2E2 exhibits specific and potent anti-tumor effect via suppression of cancer energy metabolism. However, the uncertain pharmacological effect of S -form derivative, 20( S )-Rh2E2, the by-product during the synthesis of 20( R )-Rh2E2 from parental compound 20( R/S )-Rh2 (with both R - and S -form), retarded the industrialized production, research and development of this novel effective candidate drug. In this study, 20( S )-Rh2E2 was structurally modified from pure 20( S )-Rh2, and this novel compound was directly compared with 20( R )-Rh2E2 for their in vitro and in vivo antitumor efficacy. Results showed that 20( S )-Rh2E2 effectively inhibited tumor growth and metastasis in a lung xenograft mouse model. Most importantly, animal administrated with 20( S )-Rh2E2 up to 320 mg/kg/day survived with no significant body weight lost or observable toxicity upon 7-day treatment. In addition, we revealed that 20( S )-Rh2E2 specifically suppressed cancer cell energy metabolism via the downregulation of metabolic enzyme α-enolase, leading to the reduction of lactate, acetyl-coenzyme (acetyl CoA) and adenosine triphosphate (ATP) production in Lewis lung cancer cells (LLC-1), but not normal cells. These findings are consistent to the results obtained from previous studies using a similar isomer 20( R )-Rh2E2. Collectively, current results suggested that 20( R / S )-Rh2E2 isomers could be the new and safe anti-metabolic agents by acting as the tumor metabolic suppressors, which could be generated from 20( R/S )-Rh2 in industrialized scale with low cost.
DOI: 10.1016/j.phrs.2021.105697
2021
Cited 13 times
Saponins isolated from Radix polygalae extent lifespan by modulating complement C3 and gut microbiota
With the increase in human lifespan, population aging is one of the major problems worldwide. Aging is an irreversible progressive process that affects humans via multiple factors including genetic, immunity, cellular oxidation and inflammation. Progressive neuroinflammation contributes to aging, cognitive malfunction, and neurodegenerative diseases. However, precise mechanisms or drugs targeting age-related neuroinflammation and cognitive impairment remain un-elucidated. Traditional herbal plants have been prescribed in many Asian countries for anti-aging and the modulation of aging-related symptoms. In general, herbal plants' efficacy is attributed to their safety and polypharmacological potency via the systemic manipulation of the body system. Radix polygalae (RP) is a herbal plant prescribed for anti-aging and the relief of age-related symptoms; however, its active components and biological functions remained un-elucidated. In this study, an active methanol fraction of RP containing 17 RP saponins (RPS), was identified. RPS attenuates the elevated C3 complement protein in aged mice to a level comparable to the young control mice. The active RPS also restates the aging gut microbiota by enhancing beneficial bacteria and suppressing harmful bacteria. In addition, RPS treatment improve spatial reference memory in aged mice, with the attenuation of multiple molecular markers related to neuroinflammation and aging. Finally, the RPS improves the behavior and extends the lifespan of C. elegans, confirming the herbal plant's anti-aging ability. In conclusion, through the mouse and C. elegas models, we have identified the beneficial RPS that can modulate the aging process, gut microbiota diversity and rectify several aging-related phenotypes.
DOI: 10.1016/j.jare.2021.08.015
2022
Cited 8 times
Far infrared irradiation suppresses experimental arthritis in rats by down-regulation of genes involved inflammatory response and autoimmunity
Far-infrared radiation (FIR) is widely used in the treatment of various diseases such as insomnia and cardiovascular risk. Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease in which the therapeutic potential of FIR in RA is unclear. To determine the therapeutic potential and mechanistic actions of FIR in treatment of RA. Adjuvant-induced arthritis (AIA) rat models were established to assess the therapeutic potency of FIR in RA treatment. The scoring parameters such as arthritis score, swelling of the hind paw, spleen and thymus indices, micro-CT analysis indices were adopted to estimate the beneficial effects of FIR during RA treatment in AIA model. PCR gene expression arrays were used to analyze inflammatory and autoimmune genes expression profiles in rat synovium. The inflammatory and immunity genes profiling was further analyzed through transcription factor prediction using PROMO. A signaling network map of possible molecular circuits connecting the identified differential genes to the RA's pathogenesis was constructed based on extensive literature reviews, and the major signaling pathways were validated by Western blotting. Thirty minutes of FIR treatment significantly improved the symptoms of AIA in rats. Gene expression profiling indicated that 27 out of 370 genes were down-regulated by FIR. AP-1, CEBPα, CEBPβ, c-Fos, GR, HNF-3β, USF-1, and USF-2 were predicted as key transcription factors that regulated the identified differential genes. In addition, MAPK, PI3K-Akt, and NF-κB signaling are the major molecular pathways down-regulated by FIR treatment. FIR may provide beneficial effects on the AIA rat model of arthritis by suppression of the MAPK, PI3K-Akt and NF-κB signaling pathways. Therefore, we believe that FIR may provide an alternative non-pharmacological and non-surgical therapeutic approach for the treatment of RA.
DOI: 10.3390/ph15030360
2022
Cited 7 times
Biological Evaluation in Resistant Cancer Cells and Study of Mechanism of Action of Arylvinyl-1,2,4-Trioxanes
1,2,4-trioxane is a pharmacophore, which possesses a wide spectrum of biological activities, including anticancer effects. In this study, the cytotoxic effect and anticancer mechanism of action of a set of 10 selected peroxides were investigated on five phenotypically different cancer cell lines (A549, A2780, HCT8, MCF7, and SGC7901) and their corresponding drug-resistant cancer cell lines. Among all peroxides, only 7 and 8 showed a better P-glycoprotein (P-gp) inhibitory effect at a concentration of 100 nM. These in vitro results were further validated by in silico docking and molecular dynamic (MD) studies, where compounds 7 and 8 exhibited docking scores of -7.089 and -8.196 kcal/mol, respectively, and remained generally stable in 100 ns during MD simulation. Further experiments revealed that peroxides 7 and 8 showed no significant effect on ROS accumulations and caspase-3 activity in A549 cells. Peroxides 7 and 8 were also found to decrease cell membrane potential. In addition, peroxides 7 and 8 were demonstrated to oxidize a flavin cofactor, possibly elucidating its mechanism of action. In conclusion, apoptosis induced by 1,2,4-trioxane was shown to undergo via a ROS- and caspase-3-independent pathway with hyperpolarization of cell membrane potential.
DOI: 10.1016/j.ejphar.2023.176084
2023
L-type calcium ion channel-mediated activation of autophagy in vascular smooth muscle cells via thonningianin A (TA) alleviates vascular calcification in type 2 diabetes mellitus
Vascular calcification (VC) is associated with increased morbidity and mortality, especially among people with type 2 diabetes mellitus (T2DM). The pathogenesis of vascular calcification is incompletely understood, and until now, there have been no effective therapeutics for vascular calcification. The L-type calcium ion channel in the cell membrane is vital for Ca2+ influx. The effect of L-type calcium ion channels on autophagy remains to be elucidated. Here, the natural compound thonningianin A (TA) was found to ameliorate vascular calcification in T2DM via the activation of L-type calcium ion channels. The results showed that TA had a concentration-dependent ability to decrease the transcriptional and translational expression of the calcification-related proteins runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteopontin (OPN) (P < 0.01) via ATG7-dependent autophagy in β-glycerophosphate (β-GP)- and high glucose (HG)-stimulated primary mouse aortic smooth muscle cells (MASMCs) and alleviate aortic vascular calcification in VitD3-stimulated T2DM mice. However, nifedipine, an inhibitor of L-type calcium ion channels, reversed TA-induced autophagy and Ca2+ influx in MASMCs. Molecular docking analysis revealed that TA was located in the hydrophobic pocket of Cav1.2 α1C and was mainly composed of the residues Ile, Phe, Ala and Met, which confirmed the efficacy of TA in targeting the L-type calcium channel of Cav1.2 on the cell membrane. Moreover, in an in vivo model of vascular calcification in T2DM mice, nifedipine reversed the protective effects of TA on aortic calcification and the expression of the calcification-related proteins RUNX2, BMP2 and OPN (P < 0.01). Collectively, the present results reveal that the activation of cell membrane L-type calcium ion channels can induce autophagy and ameliorate vascular calcification in T2DM. Thonningianin A (TA) can target and act as a potent activator of L-type calcium ion channels. Thus, this research revealed a novel mechanism for autophagy induction via L-type calcium ion channels and provided a potential therapeutic for vascular calcification in T2DM.
DOI: 10.1038/srep36044
2016
Cited 15 times
Antagonizing STAT5B dimerization with an osmium complex
Abstract Targeting STAT5 is an appealing therapeutic strategy for the treatment of hematologic malignancies and inflammation. Here, we present the novel osmium(II) complex 1 as the first metal-based inhibitor of STAT5B dimerization. Complex 1 exhibited superior inhibitory activity against STAT5B DNA binding compared to STAT5A DNA binding. Moreover, 1 repressed STAT5B transcription and blocked STAT5B dimerization via binding to the STAT5B protein, thereby inhibiting STAT5B translocation to the nucleus. Furthermore, 1 was able to selectively inhibit STAT5B phosphorylation without affecting the expression level of STAT5B.
DOI: 10.5530/pc.2020.1.8
2019
Cited 14 times
Antiproliferative Activity of Secondary Metabolites from Zanthoxylum zanthoxyloides Lam: In vitro and in silico Studies
DOI: 10.1038/s41423-020-0380-4
2020
Cited 13 times
Sirtuin 5 deficiency increases disease severity in rats with adjuvant-induced arthritis
DOI: 10.1016/j.gendis.2023.02.007
2023
The potential development of drug resistance in rheumatoid arthritis patients identified with p53 mutations
DOI: 10.1016/j.phrs.2023.106874
2023
Tricin promoted ATG-7 dependent autophagic degradation of α-synuclein and dopamine release for improving cognitive and motor deficits in Parkinson's disease
Tricin, a natural nontoxic flavonoid distributed in grasses and euphorbia plants, has been reported to scavenge free radicals, possess anti-inflammatory and antioxidative effects. However, its autophagic effect on Parkinson's disease (PD) has not been elucidated. By adopting cellular and C. elegans models of PD, the autophagic effect of tricin was identified based on the level of autophagy markers (LC3-II and p62). Besides, the pharmacological effects on neurotransmitters (dopamine), inflammatory cytokines (IFN γ, TNFα, MCP-1, IL-10, IL-6 and IL-17A), histology (hematoxylin & eosin and Nissl staining) and behavioural pathology (open-field test, hindlimb clasping, Y-maze, Morris water-maze and nest building test) were also confirmed in the A53T-α-synuclein transgenic PD mouse model. Further experiments demonstrated that tricin induced autophagic flux and lowered the level of α-synuclein through AMPK-p70s6K- and ATG7-dependent mechanism. Compared to the existing clinical PD drugs, tricin mitigated pathogenesis and symptoms of PD with no observable side effects. In summary, tricin is proposed as a potential adjuvant remedy or nutraceutical for the prevention and treatment of PD.
DOI: 10.1016/j.molstruc.2024.138158
2024
Synthesis and in vitro characterization of naproxen derivatives as novel anti-inflammatory agents
Naproxen, one type of non-steroidal anti-inflammatory drugs, has excellent anti-inflammatory activity. However, long-term use of it causes serious adverse effects. Inspired by the biological diversification of cinnamic acid, novel naproxen derivatives containing cinnamic acid are synthesized and used to improve their anti-inflammatory activity and safety. Our results indicated that thirty naproxen derivatives have different inhibitory effects on RAW264.7 macrophage cells. It is showed that most of the target naproxen derivatives possess the lower degree of cytotoxicity than that of naproxen. Further studies indicated that compound 22 (IC50 = 8.74 ± 2.13 μM) concentration-dependently inhibits the over-expression of iNOS, COX-2 and IL-1β by blocking the activation of nuclear factor kappa-B (NF-κB) signaling pathway and NLRP-3 inflammasome, respectively. Docking studies showed that the binding of compound 22 to NLRP3 using a well-fitting mode. It is found that compound 22 will be a novel anti-inflammatory agent to treat inflammatory diseases with an improved safety profile.
DOI: 10.2139/ssrn.4826319
2024
Gynostemma Pentaphyllum Saponins Shield Mice from Peanut Allergy by Modulation of Gut Microbiota: A Novel Approach for Peanut Allergy Management
DOI: 10.1177/2211068216645292
2017
Cited 14 times
Polypeptide-Based Gold Nanoshells for Photothermal Therapy
Targeted killing of cancer cells by engineered nanoparticles holds great promise for noninvasive photothermal therapy applications. We present the design and generation of a novel class of gold nanoshells with cores composed of self-assembled block copolypeptide vesicles with photothermal properties. Specifically, poly(L-lysine)60-block-poly(L-leucine)20 (K60L20) block copolypeptide vesicles coated with a thin layer of gold demonstrate enhanced absorption of light due to surface plasmon resonance (SPR) in the near-infrared range. We show that the polypeptide-based K60L20 gold nanoshells have low toxicity in the absence of laser exposure, significant heat generation upon exposure to near-infrared light, and, as a result, localized cytotoxicity within the region of laser irradiation in vitro. To gain a better understanding of our gold nanoshells in the context of photothermal therapy, we developed a comprehensive mathematical model for heat transfer and experimentally validated this model by predicting the temperature as a function of time and position in our experimental setup. This model can be used to predict which parameters of our gold nanoshells can be manipulated to improve heat generation for tumor destruction. To our knowledge, our results represent the first ever use of block copolypeptide vesicles as the core material of gold nanoshells.
DOI: 10.1016/j.ejmech.2021.113685
2021
Cited 9 times
Novel halogenated arylvinyl-1,2,4 trioxanes as potent antiplasmodial as well as anticancer agents: Synthesis, bioevaluation, structure-activity relationship and in-silico studies
Herein, we have synthesized a series of lipophilic, halogenated-arylvinyl-1,2,4-trioxanes 8a-g (28 compounds) and assessed for their in vitro anti-plasmodial activity in Plasmodium falciparum culture using SYBRgreen-I fluorescence assay against chloroquine-resistant Pf INDO and artemisinin-resistant Pf Cam 3.1R539T (MRA-1240) strains. Alongside, the cell cytotoxic potential of 8a-g has also been determined against the HEK293 cell line in vitro. Out of twenty-eight halogenated-arylvinyl-1,2,4-trioxanes; ten analogues (8a2, 8a4, 8b2, 8b4, 8d4, 8e1, 8e2, 8e4,8f2, and 8g4) have shown potent in vitro antiplasmodial activity with IC50 < 27 nM (IC50 range = 4.48-26.58 nM). Also, the selectivity index (SI) for these ten analogues were found in the range of 72.00-3972.50 which indicates their selective potential towards Plasmodium cells. Results of the cell cycle stage specificity with two of the most potent compounds 8a4 {(IC50 = 4.48 nM; SI = 3972.50) more potent than chloroquine (IC50 = 546 nM; SI = 36.64) and artesunate (IC50 = 6.6 nM; SI = 4333.33)} and 8e2 (IC50 = 9.69 nM; SI = 1348) against Pf INDO indicated all three stages to be the target of the action of 8e2 while only rings and trophozoites appeared to be targeted by 8a4. Ring stage survival assay against artemisinin-resistant Pf Cam 3.1R539T indicated that 8a4 may be well suited to replace artemisinin from current ACTs which are experiencing in vivo delayed parasite clearance. With intraperitoneal (i.p.) and oral (p.o.) route at the dose of 50 mg/kg/day × 4 days; 8a4 has also shown 100% suppression of parasitemia in P. berghei ANKA infected Balb C mice. Further, the in vitro anticancer activity of 8a-g performed against human lung (A549) and liver (HepG2) cancer cell lines as also against immortalized normal lung (BEAS-2B) and liver (LO2) cell lines has revealed that most of the derivatives are endowed also with promising anticancer activity (IC50 = 0.69-15 μM; SI = 1.02-20.61) in comparison with standard drugs such as chloroquine (IC50 = 100 μM; SI = 0.03), artemisinin (IC50 = 100 μM), and artesunic acid (IC50 = 9.85 μM; SI = 0.76), respectively. All the derivatives have shown moderate anticancer activity against liver (HepG2) cancer cell lines. Arylvinyl-1,2,4-trioxanes 8f2 (IC50 = 0.69 μM; SI = 16.66), the most active compound of the series, has shown ∼145 fold more cytotoxic potential with higher selectivity in comparison to reference drugs chloroquine (IC50 = 100 μM; SI = 0.03) and artemisinin (IC50 = 100 μM), respectively against the lung (A549) cancer cell line. Finally, the in-silico docking studies of the potent halogenated 1,2,4-trioxanes along with reference drug molecules against epidermal growth factor receptor (EGFR; PDB ID: 1M17) have demonstrated the strong virtual interaction.
DOI: 10.3390/molecules22091514
2017
Cited 12 times
Four Prenylflavone Derivatives with Antiplasmodial Activities from the Stem of Tephrosia purpurea subsp. leptostachya
Four new flavones with modified prenyl groups, namely (E)-5-hydroxytephrostachin (1), purleptone (2), (E)-5-hydroxyanhydrotephrostachin (3), and terpurlepflavone (4), along with seven known compounds (5–11), were isolated from the CH2Cl2/MeOH (1:1) extract of the stem of Tephrosia purpurea subsp. leptostachya, a widely used medicinal plant. Their structures were elucidated on the basis of NMR spectroscopic and mass spectrometric evidence. Some of the isolated compounds showed antiplasmodial activity against the chloroquine-sensitive D6 strains of Plasmodium falciparum, with (E)-5-hydroxytephrostachin (1) being the most active, IC50 1.7 ± 0.1 μM, with relatively low cytotoxicity, IC50 > 21 μM, against four cell-lines.
DOI: 10.1177/2211068216669710
2017
Cited 11 times
Engineering A11 Minibody-Conjugated, Polypeptide-Based Gold Nanoshells for Prostate Stem Cell Antigen (PSCA)–Targeted Photothermal Therapy
Currently, there is no curative treatment for advanced metastatic prostate cancer, and options, such as chemotherapy, are often nonspecific, harming healthy cells and resulting in severe side effects. Attaching targeting ligands to agents used in anticancer therapies has been shown to improve efficacy and reduce nonspecific toxicity. Furthermore, the use of triggered therapies can enable spatial and temporal control over the treatment. Here, we combined an engineered prostate cancer-specific targeting ligand, the A11 minibody, with a novel photothermal therapy agent, polypeptide-based gold nanoshells, which generate heat in response to near-infrared light. We show that the A11 minibody strongly binds to the prostate stem cell antigen that is overexpressed on the surface of metastatic prostate cancer cells. Compared to nonconjugated gold nanoshells, our A11 minibody-conjugated gold nanoshell exhibited significant laser-induced, localized killing of prostate cancer cells in vitro. In addition, we improved upon a comprehensive heat transfer mathematical model that was previously developed by our laboratory. By relaxing some of the assumptions of our earlier model, we were able to generate more accurate predictions for this particular study. Our experimental and theoretical results demonstrate the potential of our novel minibody-conjugated gold nanoshells for metastatic prostate cancer therapy.
DOI: 10.1038/s41598-020-59340-5
2020
Cited 9 times
TAK1 signaling regulates p53 through a mechanism involving ribosomal stress
Abstract Triple-negative breast cancer (TNBC) is among the most aggressive forms of breast cancer with limited therapeutic options. TAK1 is implicated in aggressive behavior of TNBC, while means are not fully understood. Here, we report that pharmacological blockade of TAK1 signaling hampered ribosome biogenesis (RBG) by reducing expression of RBG regulators such as RRS1, while not changing expression of ribosomal core proteins. Notably, TAK1 blockade upregulated expression of p53 target genes in cell lines carrying wild type (wt) TP53 but not in p53-mutant cells, suggesting involvement of ribosomal stress in the response. Accordingly, p53 activation by blockade of TAK1 was prevented by depletion of ribosomal protein RPL11. Further, siRNA-mediated depletion of TAK1 or RELA resulted in RPL11-dependent activation of p53 signaling. Knockdown of RRS1 was sufficient to disrupt nucleolar structures and resulted in activation of p53. TCGA data showed that TNBCs express high levels of RBG regulators, and elevated RRS1 levels correlate with unfavorable prognosis. Cytotoxicity data showed that TNBC cell lines are more sensitive to TAK1 inhibitor compared to luminal and HER2 + cell lines. These results show that TAK1 regulates p53 activation by controlling RBG factors, and the TAK1-ribosome axis is a potential therapeutic target in TNBC.
DOI: 10.20892/j.issn.2095-3941.2020.0128
2020
Cited 9 times
HM30181A, a potent P-glycoprotein inhibitor, potentiates the absorption and &lt;i&gt;in vivo&lt;/i&gt; antitumor efficacy of paclitaxel in an orthotopic brain tumor model
<h3>Objective:</h3> Delivery of chemotherapeutic drugs to the brain has remained a major obstacle in the treatment of glioma, owing to the presence of the blood-brain barrier and the activity of P-gp, which pumps its substrate back into the systemic circulation. The aim of the present study was to develop an intravenous formulation of HM30181A (HM) to inhibit P-gp in the brain to effectively deliver paclitaxel (PTX) for the treatment of malignant glioma. <h3>Methods:</h3> Two formulations of solubilized HM were designed on the basis of different solid dispersion strategies: i) spray-drying [polyvinlypyrrolidone (PVP)-HM] and ii) solvent evaporation [HP-β-cyclodextrin (cyclodextrin)-HM]. The P-gp inhibition of these 2 formulations was assessed on the basis of rhodamine 123 uptake in cancer cells. Blood and brain pharmacokinetic parameters were also determined, and the antitumor effect of cyclodextrin-HM with PTX was evaluated in an orthotopic glioma xenograft mouse model. <h3>Results:</h3> Although both PVP-HM and cyclodextrin-HM formulations showed promising P-gp inhibition activity <i>in vitro</i>, cyclodextrin-HM had a higher maximum tolerated dose in mice than did PVP-HM. Pharmacokinetic study of cyclodextrin-HM revealed a plasma concentration plateau at 20 mg/kg, and the mice began to lose weight at doses above this level. Cyclodextrin-HM (10 mg/kg) administered with PTX at 10 mg/kg showed optimal antitumor activity in a mouse model, according to both tumor volume measurement and survival time (<i>P</i> &lt; 0.05). <h3>Conclusions:</h3> In a mouse orthotopic brain tumor model, the intravenous co-administration of cyclodextrin-HM with PTX showed potent antitumor effects and therefore may have potential for glioma therapy in humans.
DOI: 10.1080/14786419.2022.2057492
2022
Cited 5 times
Exploring SARS-CoV-2 Delta variant spike protein receptor-binding domain (RBD) as a target for tanshinones and antimalarials
The interaction of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain (RBD) of spike protein with angiotensin-converting enzyme 2 (ACE2) mediates cell invasion. While this interaction mechanism is conserved, the RBD is affected by amino acid mutations in variants such as Delta and Omicron, resulting in enhanced transmissibility and altered ligand binding. Tanshinones are currently investigated as multi-target antiviral agents, but the studies were limited to the original SARS-CoV-2. This study aims at investigating the interaction of tanshinones with the Delta RBD. Chloroquine, methylene blue and pyronaridine, antimalarials previously identified as SARS-CoV-2 RBD binders, were studied for reference. Docking indicated the best scores for tanshinones, while bio-layer interferometry and molecular dynamics highlighted methylene blue as the best Delta RBD binder, although with decreased affinity with respect to the original strain.
DOI: 10.1016/0736-5845(95)00026-7
1996
Cited 22 times
The practical implementation of time-optimal control for robotic manipulators
This paper presents experimental results for time-optimal control of robotic manipulators along specified paths. The implementation of time-optimal control represents several unique problems: (1) the control is generally discontinuous (bang-bang), (2) actuator dynamics are usually ignored in order to reduce the system order, and (3) the optimal control leaves no control authority to compensate for tracking errors caused by unmodeled dynamic and the delays introduced by the on-line feedback controller. To overcome these difficulties, we compensate for motor dynamics using a simplified friction model, and account for the dynamics of the feedback controller using trajectory preshaping. Implemented for the UCLA Direct Drive Arm, this is shown to drastically reduce the tracking errors compared to the errors obtained with no preshaping and no compensation for motor dynamics. The experimental results demonstrate the merit of time optimal control for reducing motion time as well as for increasing tracking accuracy.
DOI: 10.1016/j.bmcl.2004.04.053
2004
Cited 20 times
Design, synthesis, and evaluation of a new class of noncyclic 1,3-dicarbonyl compounds as PPARα selective activators
Lipid accumulation in nonadipose tissues is increasingly linked to the development of type 2 diabetes in obese individuals. We report here the design, synthesis, and evaluation of a series of novel PPARα selective activators containing 1,3-dicarbonyl moieties. Structure–activity relationship studies led to the identification of PPARα selective activators (compounds 10, 14, 17, 18, and 21) with stronger potency and efficacy to activate PPARα over PPARγ and PPARδ. Experiments in vivo showed that compounds 10, 14, and 17 had blood glucose lowering effect in diabetic db/db mouse model after two weeks oral dosing. The data strongly support further testing of these lead compounds in other relevant disease animal models to evaluate their potential therapeutic benefits.
DOI: 10.3390/m1213
2021
Cited 7 times
N-[7-Chloro-4-[4-(phenoxymethyl)-1H-1,2,3-triazol-1-yl]quinoline]-acetamide
The 1,2,3-triazole is a well-known biologically active pharmacophore constructed by the copper-catalyzed azide–alkyne cycloaddition. We herein reported the synthesis of 4-amino-7-chloro-based [1,2,3]-triazole hybrids via Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition of 4-azido-7-chloroquinoline with an alkyne derivative of acetaminophen. The compound was fully characterized by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV) and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro with different normal and cancer cell lines. The drug likeness of the compound was also investigated by predicting its pharmacokinetic properties.
DOI: 10.3389/fphar.2021.692431
2021
Cited 7 times
AGEs-Induced Calcification and Apoptosis in Human Vascular Smooth Muscle Cells Is Reversed by Inhibition of Autophagy
Vascular calcification (VC) in macrovascular and peripheral blood vessels is one of the main factors leading to diabetes mellitus (DM) and death. Apart from the induction of vascular calcification, advanced glycation end products (AGEs) have also been reported to modulate autophagy and apoptosis in DM. Autophagy plays a role in maintaining the stabilization of the external and internal microenvironment. This process is vital for regulating arteriosclerosis. However, the internal mechanisms of this pathogenic process are still unclear. Besides, the relationship among autophagy, apoptosis, and calcification in HASMCs upon AGEs exposure has not been reported in detail. In this study, we established a calcification model of SMC through the intervention of AGEs. It was found that the calcification was upregulated in AGEs treated HASMCs when autophagy and apoptosis were activated. In the country, AGEs-activated calcification and apoptosis were suppressed in Atg7 knockout cells or pretreated with wortmannin (WM), an autophagy inhibitor. These results provide new insights to conduct further investigations on the potential clinical applications for autophagy inhibitors in the treatment of diabetes-related vascular calcification.
DOI: 10.3389/fphar.2019.00912
2019
Cited 8 times
A Novel Drug Resistance Mechanism: Genetic Loss of Xeroderma Pigmentosum Complementation Group C (XPC) Enhances Glycolysis-Mediated Drug Resistance in DLD-1 Colon Cancer Cells
The pro-apoptotic proteins BAX and BAK are critical regulatory factors constituting the apoptosis machinery. Downregulated expression of BAX and BAK in human colorectal cancer lead to chemotherapeutic failure and poor survival rate in patients. In this study, isogenic DLD-1 colon cancer cells and the BAX and BAK double knockout counterpart were used as the cellular model to investigate the role of BAX/BAK-associated signaling network and the corresponding downstream effects in the development of drug resistance. Our data suggested that DLD-1 colon cancer cells with BAX/BAK double-knockout were selectively resistant to a panel of FDA-approved drugs (27 out of 66), including etoposide. PCR array analysis for the transcriptional profiling of genes related to human cancer drug resistance validated the altered level of 12 genes (3 upregulated and 9 downregulated) in DLD-1 colon cancer cells lack of BAX and BAK expression. Amongst these genes, XPC responsible for DNA repairment and cellular respiration demonstrated the highest tolerance towards etoposide treatment accompanying upregulated glycolysis as revealed by metabolic stress assay in DLD-1 colon cancer cells deficient with XPC. Collectively, our findings provide insight into the search of novel therapeutic strategies and pharmacological targets to against cancer drug resistance genetically associated with BAX, BAK, and XPC, for improving the therapy of colorectal cancer via the glycolytic pathway.
DOI: 10.1080/14786419.2019.1660335
2019
Cited 8 times
Cytotoxicity of isoflavones from <i>Millettia dura</i>
The first phytochemical investigation of the flowers of Millettia dura resulted in the isolation of seven isoflavones, a flavonol and a chalcone. Eleven isoflavones and a flavonol isolated from various plant parts from this plant were tested for cytotoxicity against a panel of cell lines, and six of these showed good activity with IC50 values of 6-14 μM. Durmillone was the most active with IC50 values of 6.6 μM against A549 adenocarcinomic human alveolar basal epithelial cancer cell line with low cytotoxicity against the non-cancerous cell lines BEAS-2B (IC50 = 58.4 μM), LO2 hepatocytes (IC50 78.7 μM) and CCD19Lu fibroblasts (IC50 >100 μM).
DOI: 10.1016/j.bpj.2022.03.027
2022
Cited 4 times
Bromodomains regulate dynamic targeting of the PBAF chromatin-remodeling complex to chromatin hubs
Chromatin remodelers actively target arrays of acetylated nucleosomes at select enhancers and promoters to facilitate or shut down the repeated recruitment of RNA polymerase II during transcriptional bursting. It is poorly understood how chromatin remodelers such as PBAF dynamically target different chromatin states inside a live cell. Our live-cell single-molecule fluorescence microscopy study reveals chromatin hubs throughout the nucleus where PBAF rapidly cycles on and off the genome. Deletion of PBAF's bromodomains impairs targeting and stable engagement of chromatin in hubs. Dual color imaging reveals that PBAF targets both euchromatic and heterochromatic hubs with distinct genome-binding kinetic profiles that mimic chromatin stability. Removal of PBAF's bromodomains stabilizes H3.3 binding within chromatin, indicating that bromodomains may play a direct role in remodeling of the nucleosome. Our data suggests that PBAF's dynamic bromodomain-mediated engagement of a nucleosome may reflect the chromatin-remodeling potential of differentially bound chromatin states.
DOI: 10.29219/fnr.v66.8466
2022
Cited 4 times
Inhibition of plant essential oils and their interaction in binary combinations against tyrosinase
Essential oils (EOs), derived from aromatic plants, exhibit properties beneficial to health, such as anti-inflammatory, anti-oxidative, antidiabetic, and antiaging effects. However, the effect of EOs and their interaction in binary combinations against tyrosinase is not yet known.To evaluate the underlying mechanisms of EOs and their interaction in binary combinations against tyrosinas.We explored to investigate the inhibitory effect of 65 EOs and the interaction among cinnamon, bay, and magnolia officinalis in their binary combinations against tyrosinase. In addition, the main constituents of cinnamon, bay, and magnolia officinalis were analyzed by gas chromatography-mass spectrometry (GC-MS).The results showed that the most potent EOs against tyrosinase were cinnamon, bay, and magnolia officinalis with IC50 values of 25.7, 30.8, and 61.9 μg/mL, respectively. Moreover, the inhibitory mechanism and kinetics studies revealed that cinnamon and bay were reversible and competitive-type inhibitors, and magnolia officinalis was a reversible and mixed-type inhibitor. In addition, these results, assessed in mixtures of three binary combinations, indicated that the combination of cinnamon with bay at different dose and at dose ratio had a strong antagonistic effect against tyrosinase. Magnolia officinalis combined with cinnamon or bay experienced both antagonistic and synergistic effect in anti-tyrosinase activity.It is revealed that natural EOs would be promising to be effective anti-tyrosinase agents, and binary combinations of cinnamon, bay, and magnolia officinalis might not have synergistic effects on tyrosinase under certain condition.
DOI: 10.1080/14786419.2021.1925272
2021
Cited 6 times
A new benzophenone, and the antiplasmodial activities of the constituents of <i>Securidaca longipedunculata</i> fresen (Polygalaceae)
Extracts from Securidaca longipedunculata showed antiplasmodial activities against reference clones and clinical isolates using SYBR Green I method. A new benzophenone, 2,3,4,5-tetramethoxybenzophenone (1) was isolated and characterized along with seven known compounds: 4-hydroxy-2,3-dimethoxybenzophenone (2); 3-hydroxy-5-methoxybiphenyl (3), methyl-2-hydroxy-6-methoxybenzoate (4), benzyl-2-hydroxy-6-methoxybenzoate (5), 2-hydroxy-6-methoxybenzoic acid (6), 2,4,5-trimethoxybenzophenone (7) and 2-methoxy-3,4-methylenedioxybenzophenone (8). Compounds 1 and 2 showed ex vivo antiplasmodial activities (IC50 28.8 μM and 18.6 μM, respectively); while 5 and 8 showed in vivo activities (IC50 19.7 μM and 14.5 μM, respectively) against D6 strain. In a cytotoxicity assay, all the extracts (with an exception of the MeOH extract of the leaves) and pure compounds were not toxic to the normal LO2 and BEAS cell-lines, while the methanol roots extract (IC50 66.4 µg/mL against A549, and 77.4 µg/mL against HepG2), compounds 6 (IC50 22.2 µM against A549) and 7 (IC50 45.2 µM against HepG2) were weakly active against cancerous cell-lines.
DOI: 10.3389/fphar.2021.710679
2021
Cited 5 times
Autophagy Modulators From Chinese Herbal Medicines: Mechanisms and Therapeutic Potentials for Asthma
Asthma has become a global health issue, suffering more than 300 million people in the world, which is a heterogeneous disease, usually characterized by chronic airway inflammation and airway hyperreactivity. Combination of inhaled corticosteroids (ICS) and long acting β-agonists (LABA) can relieve asthma symptoms and reduce the frequency of exacerbations, especially for patients with refractory asthma, but there are limited treatment options for people who do not gain control on combination ICS/LABA. The increase in ICS dose generally provides little additional benefit, and there is an increased risk of side effects. Therefore, therapeutic interventions integrating the use of different agents that focus on different targets are needed to overcome this set of diseases. Some findings suggest autophagy is closely correlated with the severity of asthma through eosinophilic inflammation, and its modulation may provide novel therapeutic approaches for severe allergic asthma. The chinese herbal medicine (CHM) have been demonstrated clinically as potent therapeutic interventions for asthma. Moreover some reports have found that the bioactive components isolated from CHM could modulate autophagy, and exhibit potent Anti-inflammatory activity. These findings have implied the potential for CHMs in asthma or allergic inflammation therapy via the modulation of autophagy. In this review, we discuss the basic pathomechanisms underpinning asthma, and the potential role of CHMs in treating asthma with modulating autophagy.
DOI: 10.1111/cbdd.14187
2022
Cited 3 times
Combining computational and experimental evidence on the activity of antimalarial drugs on <scp>papain‐like</scp> protease of <scp>SARS‐CoV</scp>‐2: A repurposing study
The development of inhibitors that target the papain-like protease (PLpro) has the potential to counteract the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the agent causing coronavirus disease 2019 (COVID-19). Based on a consideration of its several downstream effects, interfering with PLpro would both revert immune suppression exerted by the virus and inhibit viral replication. By following a repurposing strategy, the current study evaluates the potential of antimalarial drugs as PLpro inhibitors, and thereby the possibility of their use for treatment of SARS-CoV-2 infection. Computational tools were employed for structural analysis, molecular docking, and molecular dynamics simulations to screen antimalarial drugs against PLpro, and in silico data were validated by in vitro experiments. Virtual screening highlighted amodiaquine and methylene blue as the best candidates, and these findings were complemented by the in vitro results that indicated amodiaquine as a μM PLpro deubiquitinase inhibitor. The results of this study demonstrate that the computational workflow adopted here can correctly identify active compounds. Thus, the highlighted antimalarial drugs represent a starting point for the development of new PLpro inhibitors through structural optimization.
DOI: 10.3390/m1351
2022
2-Bromo-3-((1-(7-chloroquinolin-4-yl)-1H-1,2,3-triazol-4-yl)-methoxy)-benzaldehyde
The 1,2,3-triazole ring system can be easily obtained by copper-catalyzed click reaction of azides with alkynes. 1,2,3-Triazole exhibits a myriad of biological activities, including antimalarial, antibacterial, and antiviral activities. We herein reported the synthesis of quinoline-based [1,2,3]-triazole hybrid via Cu(I)-catalyzed click reaction of 4-azido-7-chloroquinoline with alkyne derivative of 2-bromobenzaldehyde. The compound was fully characterized by proton nuclear magnetic resonance (1H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), heteronuclear single quantum coherence (HSQC), ultraviolet (UV), and high-resolution mass spectroscopies (HRMS). This compound was screened in vitro against two different normal cell lines. Preliminary studies attempted to evaluate its interaction with Delta RBD of spike protein of SARS-CoV-2 by bio-layer interferometry. Finally, the drug-likeness of the compound was also investigated by predicting its pharmacokinetic properties.
DOI: 10.1016/j.ejmech.2022.114402
2022
Design, synthesis and antitumor evaluation of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein
In this work, a series of novel 1H-indole-2-carboxylic acid derivatives targeting 14-3-3η protein were designed and synthesized for treatment of liver cancer. After structural optimization for several rounds, C11 displayed a relatively better affinity with 14-3-3η, as well as the best inhibitory activities against several typical human liver cancer cell lines, including Bel-7402, SMMC-7721, SNU-387, Hep G2 and Hep 3B cells. Compound C11 also displayed best inhibitory activity against chemotherapy-resistant Bel-7402/5-Fu cells. Besides, C11 was rather safe against hERG and possessed moderate T1/2 and CL values in liver microsomes. In anti-proliferation, trans-well and cell apoptosis assays, C11 also showed its huge potential as a potent antitumor agent. Then, Western blot assay was conducted, following analyzed by molecular docking, the anti-proliferative mechanisms of this small-molecule inhibitor were revealed. Moreover, C11 was demonstrated to induce G1-S phase cell cycle arrest in liver cancer cells.
DOI: 10.3389/fphar.2021.647280
2021
Cited 3 times
Profiling Ribonucleotide and Deoxyribonucleotide Pools Perturbed by Remdesivir in Human Bronchial Epithelial Cells
Remdesivir (RDV) has generated much anticipation for its moderate effect in treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the unsatisfactory survival rates of hospitalized patients limit its application to the treatment of coronavirus disease 2019 (COVID-19). Therefore, improvement of antiviral efficacy of RDV is urgently needed. As a typical nucleotide analog, the activation of RDV to bioactive triphosphate will affect the biosynthesis of endogenous ribonucleotides (RNs) and deoxyribonucleotides (dRNs), which are essential to RNA and DNA replication in host cells. The imbalance of RN pools will inhibit virus replication as well. In order to investigate the effects of RDV on cellular nucleotide pools and on RNA transcription and DNA replication, cellular RNs and dRNs concentrations were measured by the liquid chromatography-mass spectrometry method, and the synthesis of RNA and DNA was monitored using click chemistry. The results showed that the IC 50 values for BEAS-2B cells at exposure durations of 48 and 72 h were 25.3 ± 2.6 and 9.6 ± 0.7 μM, respectively. Ten (10) μM RDV caused BEAS-2B arrest at S-phase and significant suppression of RNA and DNA synthesis after treatment for 24 h. In addition, a general increase in the abundance of nucleotides and an increase of specific nucleotides more than 2 folds were observed. However, the variation of pyrimidine ribonucleotides was relatively slight or even absent, resulting in an obvious imbalance between purine and pyrimidine ribonucleotides. Interestingly, the very marked disequilibrium between cytidine triphosphate (CTP) and cytidine monophosphate might result from the inhibition of CTP synthase. Due to nucleotides which are also precursors for the synthesis of viral nucleic acids, the perturbation of nucleotide pools would block viral RNA replication. Considering the metabolic vulnerability of endogenous nucleotides, exacerbating the imbalance of nucleotide pools imparts great promise to enhance the efficacy of RDV, which possibly has special implications for treatment of COVID-19.
DOI: 10.1016/s0022-5347(18)38080-7
2004
Cited 4 times
831: Temperature Monitored Prostate Cryosurgery: 8 Year Accrued Clinical Experience
You have accessJournal of UrologyDiscussed Poster, Monday, May 10, 2004, 8:00am - 12:00 pm1 Apr 2004831: Temperature Monitored Prostate Cryosurgery: 8 Year Accrued Clinical Experience Douglas O. Chinn, Wilson W. Wong, Mahlon Chinn, Vincent K. Wong, and Michael R. Chinn Douglas O. ChinnDouglas O. Chinn More articles by this author , Wilson W. WongWilson W. Wong More articles by this author , Mahlon ChinnMahlon Chinn More articles by this author , Vincent K. WongVincent K. Wong More articles by this author , and Michael R. ChinnMichael R. Chinn More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)38080-7AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "831: Temperature Monitored Prostate Cryosurgery: 8 Year Accrued Clinical Experience." The Journal of Urology, 171(4S), p. 219 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 171Issue 4SApril 2004Page: 219 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Douglas O. Chinn More articles by this author Wilson W. Wong More articles by this author Mahlon Chinn More articles by this author Vincent K. Wong More articles by this author Michael R. Chinn More articles by this author Expand All Advertisement PDF downloadLoading ...
DOI: 10.1515/bc.2003.127
2003
Cited 4 times
Cloning and Characterization of the Promoter Region of the Mouse Frizzled-Related Protein 4 Gene
Frizzled-related protein (Frp) is a newly identified family of secreted proteins involved in the Wnt signaling pathway. To date, little is known about the underlying mechanisms regulating Frp expression. In this study the promoter region of mouse frizzled related protein 4 (sFrp4) gene was cloned, sequenced, and analyzed using transient reporter assays along with site-directed mutagenesis. Two clusters of cis-acting elements, STAT3/Lyf-1/MZF1 (site 1) and C/EBP-beta/ GATA-1/CREB (site 2) located in the promoter region from -238 to -144 were found to be essential for the promoter activity of sFrp4. In addition to sites 1 and 2, putative transcriptional factor binding sites for TFIID, SP1/GC and ATF/CREB exhibited positive, while the site for NRSE exhibited negative regulatory functions, as determined by the alkaline phosphatase activities of the reporter assay. We also demonstrate that the ATF/CREB site may cooperatively interact with the NRSF-like element in regulating sFrp4 promoter activity. The data of our study, which is the first promoter analysis of mouse Frp genes, provide the basis for understanding the functions and the regulation of Frp and its role in regulating Wnt signals.
DOI: 10.1002/anie.201809461
2018
Inside Back Cover: Selective Inhibition of Lysine‐Specific Demethylase 5A (KDM5A) Using a Rhodium(III) Complex for Triple‐Negative Breast Cancer Therapy (Angew. Chem. Int. Ed. 40/2018)
A rhodium(III)-based inhibitor of lysine-specific demethylase 5A has been developed. In their Commmunication on page 13091 ff., V. K. W. Wong, D. L. Ma, C.-H. Leung et al. report this rhodium(III) complex that exhibited potent anti-tumor activity in an in vivo mouse model of triple-negative breast cancer, one of the most difficult to treat forms of breast cancer. The complex may be used as a novel scaffold for further development of more potent epigenetic agents against cancers, including TNBC.
DOI: 10.1016/j.antiviral.2022.105482
2023
Ciliatoside A, isolated from Peristrophe japonica, inhibits HBsAg expression and cccDNA transcription by inducing autophagy
Hepatitis B surface antigen (HBsAg) loss and seroconversion are considered as an end point of a functional cure. Therefore, it is crucial to find new agents which could efficiently decrease HBsAg. Traditional herbal plants have been considered as an important source of new hepatitis B drugs development for their extensive use in antimicrobial and anti-inflammation. In this study, Peristrophe japonica, which could remarkably reduce HBsAg in the supernatant of HepG2.2.15 cells, was screened out for further extraction. Here, an active ethyl acetate fraction of Peristrophe japonica containing 34 sub-fractions was extracted. Subsequently, the monomeric compound Ciliatoside A was isolated and identified as a potential antiviral reagent with low cytotoxicity from Fraction 30. Ciliatoside A exhibited strong inhibition on intracellular and circulating HBsAg and HBV RNAs in HBV-infected cells and an HBV recombinant-cccDNA mouse model. The mechanistic study revealed that Ciliatoside A exhibited a potent anti-HBV effect through inducing autophagy-lysosomal pathway to autophagic degradation of HBc by activating AMPK-ULK1 axis and inhibiting mTOR activation. In summary, we have identified a novel antiviral compound Ciliatoside A isolated from Peristrophe japonica. This study may provide important direction and new ideas for the discovery of hepatitis B cure drugs.
DOI: 10.3390/molecules28083395
2023
Naproxen-Derived New Compound Inhibits the NF-κB, MAPK and PI3K/Akt Signaling Pathways Synergistically with Resveratrol in RAW264.7 Cells
Naproxen is widely used for anti-inflammatory treatment but it can lead to serious side effects. To improve the anti-inflammatory activity and safety, a novel naproxen derivative containing cinnamic acid (NDC) was synthesized and used in combination with resveratrol. The results showed that the combination of NDC and resveratrol at different ratios have a synergistic anti-inflammatory efficacy in RAW264.7 macrophage cells. It was indicated that the combination of NDC and resveratrol at a ratio of 2:1 significantly inhibited the expression of carbon monoxide (NO), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), induced nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2) and reactive oxygen species (ROS) without detectable side effects on cell viability. Further studies revealed that these anti-inflammatory effects were mediated by the activation of nuclear factor kappa-B (NF-κB), mitogen-activated protein kinase (MAPK) and phosphoinositide-3 kinase (PI3K)/protein kinase B (Akt) signaling pathways, respectively. Taken together, these results highlighted the synergistic NDC and resveratrol anti-inflammatory activity that could be further explored as a strategy for the treatment of inflammatory disease with an improved safety profile.
DOI: 10.3389/fncel.2023.1193362
2023
Potential enhancement of post-stroke angiogenic response by targeting the oligomeric aggregation of p53 protein
Tumor suppressor gene p53 and its aggregate have been found to be involved in many angiogenesis-related pathways. We explored the possible p53 aggregation formation mechanisms commonly occur after ischemic stroke, such as hypoxia and the presence of reactive oxygen species (ROS). The angiogenic pathways involving p53 mainly occur in nucleus or cytoplasm, with one exception that occurs in mitochondria. Considering the high mitochondrial density in brain and endothelial cells, we proposed that the cyclophilin D (CypD)-dependent vascular endothelial cell (VECs) necrosis pathway occurring in the mitochondria is one of the major factors that affects angiogenesis. Hence, targeting p53 aggregation, a key intermediate in the pathway, could be an alternative therapeutic target for post-stroke management.
DOI: 10.1016/j.bioorg.2023.106882
2023
Synthesis, docking studies and biological evaluation of 1H-1,2,3-triazole-7-chloroquinoline derivatives against SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded enveloped positive RNA virus and the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Chloroquine (CQ), an antimalarial drug, was reported to be active against several viruses including coronaviruses. The mechanism of host cell invasion by SARS-CoV-2 involves the interaction of angiotensin-converting enzyme (ACE2) with receptor-binding domain (RBD) of spike protein (S). The main protease (Mpro/3CLpro) is an attractive drug target due to its vital function in regulation of polyprotein translated from viral RNA. In this study, a series of novel quinoline-triazole hybrid compounds was synthesized and subjected to evaluations on their cytotoxicity, interactions with different variants of RBD in SARS-CoV-2 and with 3CLpro enzyme by experimental and computational techniques to identify their ability of counteracting viral infection. The results of bio-layer interferometry showed that quinoline derivative 11 has good interaction with delta plus and omicron RBD variants (KD = 3.46 × 10-5 and 6.38 × 10-5 M) while derivative 1 is the best binder for recent variant omicron (KD = 26.9 µM) among the series. Potent compounds 1-4 and 11 also demonstrated a suppressive effect on 3CLpro activity in a non-dose-dependent manner. Further docking study revealed that these compounds interacted within the same area of RBD, while no correlation was found for 3CLpro. Furthermore, the molecular dynamics simulations were carried out to assess the conformational stability of docked complexes for preliminary verification.
DOI: 10.3390/polym13234133
2021
Synthesis and Coordination Properties of a Water-Soluble Material by Cross-Linking Low Molecular Weight Polyethyleneimine with Armed Cyclotriveratrilene
In this study, a full organic and water-soluble material was synthesized by coupling low molecular weight polyethylenimine (PEI-800) with cyclotriveratrilene (CTV). The water-soluble cross-linked polymer contains hydrophobic holes with a high coordination capability towards different organic drug molecules. The coordinating capability towards hydrophilic drugs (doxorubicin, gatifloxacin and sinomenine) and hydrophobic drugs (camptothecin and celastrol) was analyzed in an aqueous medium by using NMR, UV-Vis and emission spectroscopies. The coordination of drug molecules with the armed CTV unit through hydrophobic interactions was observed. In particular, celastrol exhibited more ionic interactions with the PEI moiety of the hosting system. In the case of doxorubicin, the host-guest detachment was induced by the addition of ammonium chloride, suggesting that the intracellular environment can facilitate the release of the drug molecules.
DOI: 10.29245/2572.942x/2016/7.1070
2016
Comment: New potential pharmacological functions of Chinese herbal medicines via regulation of autophagy: the search of reliable pharmaceutical candidates for chronic disorders therapy
Chronic diseases are the leading causes of physical impairments and mortality in the world. The functional role of autophagy in maintaining cellular homeostasis implies that the molecular machinery is a compelling pharmaceutical target for such disorders involving overall body imbalance. Therefore, autophagy modulators appeared to be the ideal source for hunting of novel and effective pharmaceutical interventions. Law et al., have performed a systematic review on more than 30 different Chinese herbal medicine (CHM)-derived bioactive compounds capable of regulating autophagy activity. The successful experimental and clinical applications of these compounds which have not been previously documented have been discussed. Notably, most of the reported novel applications are associated with chronic dysfunctions.
DOI: 10.1016/s0959-8049(13)70009-1
2013
AOSOP9 TRI001 IS A NOVEL ACTIVATOR OF AUTOPHAGY VIA MTOR-DEPENDENT MECHANISMS
DOI: 10.3389/fphar.2022.837115
2022
Pimobendan Inhibits HBV Transcription and Replication by Suppressing HBV Promoters Activity
Current anti-HBV therapeutic strategy relies on interferon and nucleos(t)ide-type drugs with the limitation of functional cure, inducing hepatitis B surface antigen (HBsAg) loss in very few patients. Notably, the level of HBsAg has been established as an accurate indicator to evaluate the drug efficacy and predict the disease prognosis, thus exploring a novel drug targeting HBsAg will be of great significance. Herein, by screening 978 compounds from an FDA-approved drug library and determining the inhibitory function of each drug on HBsAg level in HepG2.2.15 cells supernatant, we identified that pimobendan (Pim) has a powerful antiviral activity with relatively low cytotoxicity. The inhibitory effect of Pim on HBsAg as well as other HBV markers was validated in HBV-infected cell models and HBV-transgenic mice. Mechanistically, real-time PCR and dual-luciferase reporter assay were applied to identify the partial correlation of transcription factor CAAT enhancer-binding protein α (C/EBPα) with the cccDNA transcription regulated by Pim. This indicates Pim is an inhibitor of HBV transcription through suppressing HBV promoters to reduce HBV RNAs levels and HBsAg production. In conclusion, Pim was identified to be a transcription inhibitor of cccDNA, thereby inhibiting HBsAg and other HBV replicative intermediates both in vitro and in vivo. This report may provide a promising lead for the development of new anti-HBV agent.
DOI: 10.1007/s10068-022-01145-5
2022
Inhibitory effect of plant essential oils on α-glucosidase
Diabetes mellitus, associated with α-glucosidase, has been considered as a chronic metabolic disorder, seriously affecting human health. Thus, searching natural α-glucosidase inhibitors and investigating their inhibition mechanism are urgently important. In this study, sixty-two essential oils (EOs), derived from aromatic plants, were found to exert different inhibition on α-glucosidase. The further study revealed that the most potent EOs against α-glucosidase were chuan-xiong, fructus cnidii, sacha inchi, aloe, ganoderma lucidum spore and ginger with IC50 values of 3.02, 2.88, 7.37, 5.06, 5.32 and 7.40 μg/mL. Moreover, the inhibitory mechanism and kinetics studies found that chuan-xiong and sacha inchi were reversible and mixed-type inhibitors. Fructus cnidii, aloe, ganoderma lucidum spore and ginger were reversible and uncompetitive-type inhibitors. It is suggested that EOs, being of natural origin, would be promising anti-α-glucosidase agents.
DOI: 10.3389/fphar.2022.988748
2022
Antimalarial and antitumour activities of the steroidal quinone-methide celastrol and its combinations with artemiside, artemisone and methylene blue
Artemisinin, isolated from the traditional Chinese medicinal plant qīng hāo (Artemisia annua) and its derivatives are used for treatment of malaria. With treatment failures now being recorded for the derivatives and companion drugs used in artemisinin combination therapies new drug combinations are urgently required. The amino-artemisinins artemiside and artemisone display optimal efficacies in vitro against asexual and sexual blood stages of the malaria parasite Plasmodium falciparum and are active against tumour cell lines. In continuing the evolution of combinations of the amino-artemisinins with new drugs, we examine the triterpenoid quinone methide celastrol isolated from the traditional Chinese medicinal plant léi gōng téng (Tripterygium wilfordii). This compound is redox active, and has attracted considerable attention because of potent biological activities against manifold targets. We report that celastrol displays good IC50 activities ranging from 0.50-0.82 µM against drug-sensitive and resistant asexual blood stage Pf, and 1.16 and 0.28 µM respectively against immature and late stage Pf NF54 gametocytes. The combinations of celastrol with each of artemisone and methylene blue against asexual blood stage Pf are additive. Given that celastrol displays promising antitumour properties, we examined its activities alone and in combinations with amino-artemisinins against human liver HepG2 and other cell lines. IC50 values of the amino-artemisinins and celastrol against HepG2 cancer cells ranged from 0.55-0.94 µM. Whereas the amino-artemisinins displayed notable selectivities (SI > 171) with respect to normal human hepatocytes, in contrast, celastrol displayed no selectivity (SI < 1). The combinations of celastrol with artemiside or artemisone against HepG2 cells are synergistic. Given the promise of celastrol, judiciously designed formulations or structural modifications are recommended for mitigating its toxicity.
2017
Genomic binding dynamics of PBAF are regulated via select chromatin states
ATP-dependent chromatin-remodeling complexes such as PBAF mediate changes in chromatin structure, leading to regulation of transcriptional bursting. PBAF is targeted to genomic loci by histone acetylation. Despite extensive in vitro studies, how these chromatin remodelers rapidly bind and discriminate genomic targets in vivo remains unclear. Therefore, we sought to understand how the PBAF complex interacts with different chromatin states using live-cell single molecule fluorescence microscopy. Dual color tracking revealed that PBAF binds H3.3 marked chromatin within actively transcribed regions for faster time periods relative to binding to HP1α containing heterochromatin. Notably, elevation of histone acetylation levels increased the frequency of PBAF revisiting to genomic foci as defined by clustered binding. Furthermore, deletion of six bromodomains within the BAF180 subunit of PBAF reduced chromatin target search efficiency, clustered binding activity, and anchoring to the genome. These findings suggest that acetyl-lysine dependent clustered binding of PBAF to select genomic loci may facilitate rapid chromatin remodeling in actively transcribed regions. Our work also indicates that the dynamics of PBAF mediated chromatin state alterations proceed at fast timescales that may fine-tune transcription regulation.
DOI: 10.1007/978-981-15-5159-8_6
2020
Tumor Therapeutic Modes
DOI: 10.1016/j.coph.2020.12.002
2020
Editorial overview: New technologies in 2020: Drug resistance
Understanding and targeting of GPCRs remain a critical aspect of airway pharmacology and therapeutics for diseases such as asthma or COPD. Most attention has been on the large Class A GPCRs towards improved bronchodilation and blunting of remodeling. Better known in the central or peripheral nervous system, there is increasing evidence that Class C GPCRs which include metabotropic glutamate and GABA receptors, the calcium sensing receptor, sweet/umami taste receptors and a number of orphan receptors, can contribute to airway structure and function. In this review, we will summarize current state of knowledge regarding the pharmacology of Class C GPCRs, their expression and potential functions in the airways, and the application of pharmacological agents targeting this group in the context of airway diseases.
DOI: 10.20944/preprints202012.0289.v1
2020
Profiling Ribonucleotide and Deoxyribonucleotide Pools Perturbed by Remdesivir in Human Bronchial Epithelial Cells
Remdesivir (RDV) has garnered much hope for its moderate anti-COVID-19 effects, but its limited amelioration of survival in hospitalized patient causes a huge controversy over the applicability of RDV to COVID-19 treatment. Developing strategies to improve its antivirus efficacy is urgently required. As anticipated, RDV exhibits similar behavior with other nucleotide analogs to disrupt the metabolism of natural endogenous ribonucleotides (RNs) and deoxyribonucleotides (dRNs). Alterations in endogenous RNs and dRNs play a critical role in virus replication as well as other key cellular functions. Thus elucidation of the disturbances of RDV on RNs and dRNs could help to understand its exact mechanism of action. Here, the metabolic profiling determined by liquid chromatography&amp;ndash;mass spectrometry method showed a general increase in the abundance of nucleotides and a more than 2-fold increase for specific nucleotides. However, the variation of pyrimidine ribonucleotides was relative slight or even contrary, resulting in obvious imbalance between purine and pyrimidine ribonucleotides, which implied the obstacle of RDV to pyrimidine synthesis and could further block the transcription and replication of viral RNA. Additionally, the extreme disequilibrium between cytidine triphosphate (CTP) and cytidine monophosphate might result from the inhibition of CTP synthase and provide a metabolic target for the treatment of COVID-19 infection. Since nucleotides metabolism pathways are vulnerable to nucleotide analogues and are liable to be the regulation targets, it is promising to enhance the efficacy of RDV through co-administration with CTP synthase inhibitors or de novo pyrimidine synthesis inhibitors to exacerbate the imbalance of nucleotide pools.
DOI: 10.1016/j.bpj.2015.11.2758
2016
Single Molecule Imaging of p53's Dynamic Interaction with Chromatin
P53 is a transcriptional activator that binds to its response elements (REs) on target promoters and activates expression of a large number of genes involved in tumor suppression. Previous genome-wide studies showed that p53 binds to its REs in regions densely populated with nucleosomes. However, it is unknown how p53 accesses its target REs in the context of chromatin to regulate transcription. To better decipher the interaction of p53 with chromatin targets, we utilized a combination of in vivo live cell and in vitro single molecule imaging along with bioinformatics and Next Generation Proteomic screens. Our live cell imaging studies indicate a dynamic interaction between p53 and chromatin that varies in distinct sub-nuclear compartments. In vitro, p53 binds a mononucleosome on a native p53 target gene with nearly identical residence times as our live cell measurements. Strikingly, p53 has a higher affinity for its RE when incorporated into nucleosomes compared to an RE on naked DNA, suggesting a novel role for p53 as a pioneer factor. In addition, p53 transiently interacts and alters the structure of nucleosomal DNA, presumably to facilitate access of additional p53 bound chromatin modifiers. Bioinformatic analysis reveal that p53 REs cluster specifically within 2 regions of the nucleosome. Interestingly, p53 interacts with peptides that have strong homology to histones H2A, H2B, and H4 in our next generation proteomic screens. Furthermore based upon crystal structures, these histone peptides are adjacent to the clustered p53 REs, strongly suggesting localization of two physiologically relevant binding platforms for p53 on the nucleosome. Collectively, our studies indicate that p53/histone contacts combined with p53's interaction with REs may enhance p53 directed transcription by creating a stable multivalent platform for p53's recruitment to target promoters.
DOI: 10.1016/j.bpj.2013.11.4463
2014
Single Molecule Probing of P53's Ability to Dynamically Regulate Chromatin Structure
The tumor suppressor p53 protein is a transcriptional activator that binds to its response elements (REs) on target promoters and activates expression of a large number of genes involved in tumor suppression. Previous ChIP-seq studies indicate that p53 binds to its REs embedded in regions densely populated with nucleosomes. However, it is unknown if nucleosomes help or hinder binding of p53 to its response elements to regulate transcription. To decipher the interaction of p53 with nucleosomes, we have utilized a combination of Next Generation Proteomics, bioinformatics, bulk biochemical and real-time single molecule FRET assays. Our proteomic assays show that p53 interacts with peptides that have strong homology to histones H2A, H2B, and H4. Biochemical assays indicate that p53 can stably interact with histone peptides in the absence of DNA. Genomic maps of p53 REs and nucleosome positions further reveal that p53 REs cluster specifically within 2 regions of the nucleosome. Furthermore these clustered p53 REs are adjacent to histone regions identified in our proteomic studies, suggesting localization of two physiologically relevant binding platforms for p53 on the nucleosome. We have also established a single molecule FRET assay to characterize dynamic structural changes in nucleosomes with and without p53 REs. Interestingly, our studies reveal that p53 can bind to our biochemically defined nucleosomal surface and dynamically alter the structure of nucleosomal DNA independently of the presence of a p53 RE. Intriguingly, p53 has a higher affinity for its RE when incorporated into nucleosomes assembled with native DNA compared to REs on naked DNA. Thus, our studies indicate that histone/p53 contacts may enhance p53 directed transcription by creating a stable platform for p53 promoter recruitment.
DOI: 10.1016/j.bpj.2013.11.4462
2014
Structural and Dynamic Regulation of TFIID-Mediated Transcription Initiation Complex Assembly by the Tumor Suppressor P53 Protein
p53 plays a central role in tumor suppression. To quickly respond to diverse stress stimuli, p53 binds specific elements in various target promoters to induce vast gene networks for maintaining cellular integrity. p53 stimulates transcription in part by aiding promoter recruitment of the transcription machinery. TFIID, a key component within the transcription machinery, is responsible for binding specific core promoter DNA sequences and recruiting other basal factors including RNA Polymerase II to initiate transcription. However, the exact mechanism underlying how p53 facilitates TFIID-mediated transcription is unclear. Each p53 target gene has a unique arrangement of p53-responsive and core promoter elements. How these various arrangements on different gene promoters regulate the structural architecture of TFIID and the positioning of p53/specific elements remains unknown. Moreover, structural information of p53 bound to its various target promoters and other factors remains elusive. Therefore, we aim to decipher the molecular mechanism underlying p53's ability to stimulate transcription by revealing the biochemical, structural and dynamic basis of TFIID bound to p53 and promoter DNA. To this end, we established unique protein purification strategies to generate high-purity native TFIID complex bound to p53/TFIIA/native promoter DNA. We next determined the 3D structures of TFIID/p53/TFIIA co-complexes on two distinct p53 target gene promoters via single particle cryo-electron microscopy. Strikingly, we discovered a common mode of TFIID binding to different types of promoters. Our biochemical studies showed that p53 significantly promotes TFIID's interaction with DNA. To further mechanistically dissect TFIID's enhanced promoter recognition/binding directed by p53, we examined the dynamic interaction between p53, TFIID and promoter DNA via single molecule TIRF microscopy. Taken together, our structural and functional studies elucidate how p53 facilitates TFIID-mediated transcription initiation complex assembly on different p53 target gene promoters.
2015
Re-epitheliazation across ethnic groups with human-like Epidermal Growth Factor (EGF)
DOI: 10.1016/s0959-8049(13)70041-8
2013
AOSP30 SAIKOSAPONIN-D POTENTIATES THE ANTICANCER EFFECT OF TNFα VIA SUPPRESSION OF TNFα-MEDIATED ACTIVATION OF NF-κ SIGNALLING
DOI: 10.1016/s1353-8020(09)70615-7
2009
P3.051 Calcium channel blockers can minimize iron-induced apoptosis in neural stem cells
2017
PBAF’s genomic binding dynamics are regulated via bromodomain-acetyl-lysine interactions and select chromatin states
Rapid changes in chromatin structure via the action of ATP-dependent chromatin-remodeling complexes are thought to dynamically regulate transcriptional bursting. Chromatin-remodeling complexes are targeted to genomic loci by histone post-translational modifications (PTMs) including acetylation. Despite extensive in vitro studies, much is still unknown about how chromatin-remodeling complexes rapidly bind genomic targets and function in vivo. We sought to understand how the PBAF chromatin-remodeling complex interacts with different chromatin states using live-cell single particle tracking of the BAF180 subunit. Dual color tracking of PBAF with either H3.3 or HP1α revealed that PBAF binds chromatin within actively transcribed regions for shorter time periods relative to heterochromatin. We also found that deletion of BAF180's six bromodomains reduced both the association and dissociation of PBAF with chromatin. Finally, elevation of histone acetylation levels increased the frequency of PBAF revisiting to genomic foci. Together, these results suggest that acetyl-lysine dependent clustered binding of PBAF to select genomic loci may facilitate rapid chromatin-remodeling in actively transcribed regions. Overall our work also indicates that the dynamics of chromatin state alterations proceed at fast timescales to potentially regulate transcriptional bursting.
2017
Four flavones with modified prenyl groups from the stem of Tephroisa purpurea subsp. Leptostachya
DOI: 10.1101/111674
2017
Bromodomains regulate dynamic targeting of the PBAF chromatin remodeling complex to chromatin hubs
Abstract Transcriptional bursting involves genes rapidly switching between active and inactive states. Chromatin remodelers actively target arrays of acetylated nucleosomes at select enhancers and promoters to facilitate or shut down the repeated recruitment of RNA Pol II during transcriptional bursting. It is unknown how acetylated chromatin is dynamically targeted and regulated by chromatin remodelers such as PBAF. Thus, we sought to understand how PBAF targets acetylated chromatin using live-cell single molecule fluorescence microscopy. Our work reveals chromatin hubs throughout the nucleus where PBAF rapidly cycles on and off the genome. Deletion of PBAF’s bromodomains impairs targeting, stable engagement and persistent binding on chromatin in hubs. Interestingly, PBAF has a higher probability to stably engage chromatin inside hubs indicating that hubs contain a unique nucleosomal scaffold compared to global chromatin. Dual color imaging of PBAF in hubs near H3.3 or HP1α reveals that PBAF targets both euchromatic and heterochromatic regions with distinct genome binding kinetics that mimic chromatin stability. Removal of PBAF’s bromodomains stabilizes H3.3 and HP1α binding within chromatin indicating that bromodomains may play a direct role in remodeling of the nucleosome. Our data, suggests that PBAF differentially and dynamically engages a variety of chromatin structures involved in both activation and repression of transcription via bromodomains. Furthermore, PBAF’s binding stability on chromatin may reflect the chromatin remodeling potential of different bound chromatin states. Statement of Significance Transcriptional bursting involves a gene rapidly switching between transcriptionally active and inactive states. To regulate transcriptional bursting, chromatin must interchange between euchromatin and heterochromatin to permit or restrict access of transcription factors including RNA Polymerase II to enhancer and gene promoters. However, little is known regarding how chromatin remodelers dynamically read a rapidly changing 4D epigenome. We used live-cell single molecule imaging to characterize the spatiotemporal chromatin binding dynamics of PBAF, a chromatin remodeler that accesses both euchromatin and heterochromatin to regulate transcription. PBAF cycles on and off chromatin hubs in select nuclear regions where it distinctly engages euchromatin and heterochromatin via bromodomains in its BAF180 subunit. Our study provides the framework to understand how the 4D epigenome is regulated.