The effect of celastrol in combination with 5-fluorouracil on proliferation and apoptosis of gastric cancer cell lines

Background:Despite the availability of chemotherapy drugs such as 5-fluorouracil(5-FU),the treatment of some cancers such as gastric cancer remains challenging due to drug resistance and side effects.This study aimed to investigate the effect of celastrol in combination with the chemotherapy drug 5-FU on proliferation and induction of apoptosis in human gastric cancer cell lines(AGS and EPG85-257).Materials and Methods:In this in vitro study,AGS and EPG85-257 cells were treated with different concentrations of celastrol,5-FU,and their combination.Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)assay.The synergistic effect of 5-FU and celastrol was studied using Compusyn software.The DNA content at different phases of the cell cycle and apoptosis rate was measured usingflow cytometry.Results:Co-treatment with low concentrations(10%inhibitory concentration(IC10))of celastrol and 5-FU significantly reduced IC50(p<0.05)so that 48 h after treatment,IC50 was calculated at 3.77 and 6.9μM for celastrol,20.7 and 11.6μM for 5-FU,and 5.03 and 4.57μM for their combination for AGS and EPG85-257 cells,respectively.The mean percentage of apoptosis for AGS cells treated with celastrol,5-FU,and their combination was obtained 23.9,41.2,and 61.9,and for EPG85-257 cells 5.65,46.9,and 55.7,respectively.In addition,the 5-FU and celastrol-5-FU combination induced cell cycle arrest in the synthesis phase.Conclusions:Although celastrol could decrease the concentration of 5-fluorouracil that sufficed to suppress gastric cancer cells,additional studies are required to arrive at conclusive evidence on the anticancer effects of celastrol.

Celastrol activates caspase-3/GSDME-dependent pyroptosis in tumor cells by inducing endoplasmic reticulum stress Author links open overlay panel

Objective:To investigate the pyroptosis-inducing effects of celastrol on tumor cells and to explore the potential mechanisms involved,specifically focusing on the role of the caspase-3/gasdermin E(GSDME)signaling pathway and the impact of endoplasmic reticulum(ER)stress and autophagy.Methods: Necrostatin-1(Nec-1),lactate dehydrogenase release(LDH)assay,and Hoechst/propidium iodide(PI)double staining were employed to validate the mode of cell death.Western blot was used to detect the cleavage of GSDME and the expression of light chain 3(LC3)and BIP.Results: Celastrol induced cell swelling with large bubbles,which is consistent with the pyroptotic phenotype.Moreover,treatment with celastrol induced GSDME cleavage,indicating the activation of GSDME-mediated pyroptosis.GSDME knockout via CRISPR/Cas9 blocked the pyroptotic morphology of celastrol in HeLa cells.In addition,cleavage of GSDME was attenuated by a specific caspase-3 inhibitor in celastrol-treated cells,suggesting that GSDME activation was induced by caspase-3.Mechanistically,celastrol induced endoplasmic reticulum(ER)stress and autophagy in HeLa cells,and other ER stress inducers produced effects consistent with those of celastrol.Conclusion: These findings suggest that celastrol triggers caspase-3/GSDME-dependent pyroptosis via activation of ER stress,which may shed light on the potential antitumor clinical applications of celastrol.

Celastrol promotes apoptosis of breast cancer MDA-MB-231 cells by targeting HSDL2

Objective:Celastrol is a pentacyclic triterpenoid extracted from the traditional Chinese medicinal herb,Tripterygium wilfordii.This study aims to provide a scientific basis for the rational development and use of celastrol in breast cancer.Method:A quantitative chemical biology approach was used to investigate the protein targets and molecular mechanisms of celastrol in breast cancer cells.Results:Low-concentration celastrol exerted an anti-tumor effect by directly binding to hydroxysteroid dehydrogenase-like 2(HSDL2)and inhibiting its expression.Moreover,the expression of the pro-apoptotic protein,Bcl-2-associated X(BaX),increased,the level of the anti-apoptotic protein,B-cell lymphoma-2(Bcl-2),decreased,and the rate of apoptosis increased.After the transfection of cells with si-HSDL2,the apoptosis rate was similar to that observed after the administration of celastrol.However,apoptosis was reversed by the overexpression of HSDL2.Furthermore,our mass spectrometry(MS)data indicated a relationship between HSDL2 and the mitogen-activated protein kinase(MAPK)signaling pathway.We also found that the expression of HSDL2 was directly related to the degree of extracellular signal-regulated kinase(ERK)phosphorylation.Conclusion:Celastrol may promote apoptosis by suppressing the HSDL2/MAPK/ERK signaling pathway.

Celastrol inhibits inflammatory factors expression in glioblastoma

Background:Glioblastoma is one of the most common primary intracranial tumors of the central nervous system in adults.Although chemotherapy is an important component of glioblastoma treatment,its effectiveness remains unsatisfactory.Due to multiple immunosuppressive mechanisms,glioblastoma immunotherapy has not been effective in treating many patients as a result of the clinical breakthroughs in the field.Therefore,the development of cancer immunotherapy relies on the understanding of how tumors interact with the immune system and the analysis of their molecular determinants.This study identified the key interactions between immune cells in the glioma microenvironment using RNA microarrays and single-cell sequencing.Methods:First,we screened differentially expressed genes in tumor and control samples from GSE29796 and GSE50161 datasets using GEO2R.All differentially expressed genes were used to perform enrichment analysis and construct protein-protein interaction topological analysis to analyze the interaction between proteins.Using single-cell RNA sequencing data from the GSE162631 database,we identified immune cell types within the glioblastoma microenvironment,and validated the hub gene expression in these cells.In addition,based on the GEPIA and TIMER databases,hub genes were investigated and compared with immune infiltration to determine differential expression.Finally,CellChat was used to visualize the gene expression distribution and cell-to-cell communication analysis of the proteins between different types of cells.Results:We found that monocytes/macrophages may communicate with each other in the tumor microenvironment through MIF-(CD74+CXCR4)and MIF-(CD74+CD44).In addition,our study indicated that celastrol has the ability to inhibit inflammatory factors expression by MIF/CD74 signaling pathway in U87 cells.Conclusion:This study improved the effectiveness of cancer immunotherapy strategies and developed new ideas for immunotherapy that can be applied to glioblastoma.

The Mechanism of Celastrol in the Treatment of Metastatic Lung Adenocarcinoma Revealed by Network Pharmacology and Molecular Docking

Background: Celastrol is an active ingredient extracted from Traditional Chinese Medicine (TCM), which can restrain the progression of lung cancer, whereas its underlying mechanism is unclear. In our study, the underlying mechanism of celastrol in the treatment of lung adenocarcinoma (LUAD) with metastasis was investigated by network pharmacology and molecular docking. Method: Potential targets of celastrol were collected from TCMSP, Batman-TCM and GeneCard database, and its potential targets were predicted using the STP platform and the TargetNet server. Metastasis marker genes (MGs) were obtained from the HCMDB. The genes correlated with LUAD were gathered from the GeneCard and OMIM database. And the common targets among celastrol potential targets, MGs and LUAD were analyzed. The protein-protein interaction (PPI) networks were obtained from the STRING database. SangerBox and the Xiantao bioinformatics tool were applied to visualize GO and KEGG analysis. Molecular docking tested the binding affinity between celastrol and core genes. Result: A total of 107 targets of celastrol against metastasis LUAD were obtained. The core targets were obtained from the PPI network, namely AKT1, JUN, MYC, STAT3, IL6, TNF, NFKB1, BCL2, IL1B, and HIF1A. GO and KEGG enrichment analysis indicated celastrol for the treatment of metastasis LUAD most refers to cellular response to chemical stress, DNA-binding transcription factor binding, transcription regulator complex and pathways in cancer. And some of these targets are associated with differential expressions and survival rates in LUAD. Moreover, Molecular docking shows celastrol can bind with BCL2 well by hydrogen bond and hydrophobic interaction. Conclusion: This finding roundly expounded the core genes and potential mechanisms of celastrol for the treatment of metastasis LUAD, offering the theoretical basis and antitumor mechanism of TCM in the treatment of lung cancer.

Celastrol targeting Nedd4 reduces Nrf2-mediated oxidative stress in astrocytes after ischemic stroke

Stroke is the second leading cause of death worldwide,and oxidative stress plays a crucial role.Celastrol exhibits strong antioxidant properties in several diseases;however,whether it can affect oxidation in cerebral ischemic-reperfusion injury(CIRI)remains unclear.This study aimed to determine whether celastrol could reduce oxidative damage during CIRI and to elucidate the underlying mechanisms.Here,we found that celastrol attenuated oxidative injury in CIRI by upregulating nuclear factor E2-related factor 2(Nrf2).Using alkynyl-tagged celastrol and liquid chromatography-tandem mass spectrometry,we showed that celastrol directly bound to neuronally expressed developmentally downregulated 4(Nedd4)and then released Nrf2 from Nedd4 in astrocytes.Nedd4 promoted the degradation of Nrf2 through K48-linked ubiquitination and thus contributed to astrocytic reactive oxygen species production in CIRI,which was significantly blocked by celastrol.Furthermore,by inhibiting oxidative stress and astrocyte activation,celastrol effectively rescued neurons from axon damage and apoptosis.Our study uncovered Nedd4 as a direct target of celastrol,and that celastrol exerts an antioxidative effect on astrocytes by inhibiting the interaction between Nedd4 and Nrf2 and reducing Nrf2 degradation in CIRI.

Celastrol mitigates inflammation in sepsis by inhibiting the PKM2-dependent Warburg effect

Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.

Mechanistic engineering of celastrol liposomes induces ferroptosis and apoptosis by directly targeting VDAC2 in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is one of most common and deadliest malignancies.Celastrol(Cel),a natural product derived from the Tripterygium wilfordii plant,has been extensively researched for its potential effectiveness in fighting cancer.However,its clinical application has been hindered by the unclear mechanism of action.Here,we used chemical proteomics to identify the direct targets of Cel and enhanced its targetability and antitumor capacity by developing a Cel-based liposomes in HCC.We demonstrated that Cel selectively targets the voltage-dependent anion channel 2(VDAC2).Cel directly binds to the cysteine residues of VDAC2,and induces cytochrome C release via dysregulating VDAC2-mediated mitochondrial permeability transition pore(mPTP)function.We further found that Cel induces ROS-mediated ferroptosis and apoptosis in HCC cells.Moreover,coencapsulation of Cel into alkyl glucoside-modified liposomes(AGCL)improved its antitumor efficacy and minimized its side effects.AGCL has been shown to effectively suppress the proliferation of tumor cells.In a xenograft nude mice experiment,AGCL significantly inhibited tumor growth and promoted apoptosis.Our findings reveal that Cel directly targets VDAC2 to induce mitochondria-dependent cell death,while the Cel liposomes enhance its targetability and reduces side effects.Overall,Cel shows promise as a therapeutic agent for HCC.

Study of molecular mechanisms underlying the medicinal plant Tripterygium wilfordii-derived compound celastrol in treating diabetic nephropathy based on network pharmacology and molecular docking

Background:Diabetic nephropathy(DN)is a serious complication of diabetes with rising prevalence worldwide.We aimed to explore the anti-DN mechanisms of the compound celastrol derived from the medicinal plant Tripterygium wilfordii.Methods:Celastrol-related targets were obtained from Herbal Ingredients’Targets(HIT)and GeneCards databases.DN-related targets were retrieved from GeneCards,DisGeNET,and Therapeutic Targets Database(TTD).A Protein-protein interaction(PPI)network was established using the Search Tool for the Retrieval of Interacting Genes(STRING)database.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analyses were performed using ClusterProfiler.The cytoHubba plugin was used to select the top 10 hub targets.Molecular docking was performed employing PyMOL and AutoDock software.Cell counting kit-8(CCK-8)and flow cytometry assays were used to detect the viability and apoptosis of NRK-52E cells,respectively.The mRNA expression levels of mitogen-activated protein kinase 3(MAPK3),tumor necrosis factor(TNF),and AKT serine/threonine kinase 1(AKT1)in NRK-52E cells were assessed using quantitative real-time polymerase chain reaction(qRT-PCR).Results:We obtained sixty-six overlapping targets of celastrol and DN.GO and KEGG analyses demonstrated that the core targets of celastrol and DN were mainly involved in the inflammatory and immune response,oxidative stress,advanced glycation end products(AGEs)and their receptors(RAGEs)(AGE-RAGE),TNF,interleukin 17(IL-17),and MAPK signaling pathways.Finally,based on the good binding activity with celastrol,MAPK3,TNF,and AKT1 were identified as the foremost targets of celastrol.We observed that celastrol enhanced the viability of high glucose(HG)-treated NRK-52E cells and inhibited apoptosis in the in vitro assays.Moreover,celastrol decreased the mRNA expression levels of MAPK3,TNF,and AKT1 in high glucose(HG)-treated NRK-52E cells.Conclusion:Celastrol may treat DN by targeting APK3,TNF,and AKT1 and regulating inflammatory responses and oxidative stress through the AGE-RAGE,TNF,IL-17,and MAPK signaling pathways.

Celastrol inhibits migration, proliferation and transforming growth factor-β2-induced epithelial-mesenchymal transition in lens epithelial cells

AIM: To investigate the mechanism of celastrol in inhibiting lens epithelial cells(LECs) fibrosis, which is the pathological basis of cataract.METHODS: Human LEC line SRA01/04 was treated with celastrol and transforming growth factor-β2(TGF-β2). Wound-healing assay, proliferation assay, flow cytometry, real-time polymerase chain reaction(PCR), Western blot and immunocytochemical staining were used to detect the pathological changes of celastrol on LECs. Then, we cultured Sprague-Dawley rat lens in medium as a semi-in vivo model to find the function of celastrol further.RESULTS: We found that celastrol inhibited the migration of LECs, as well as proliferation(P<0.05). In addition, it induced the G2/M phase arrest by cell cyclerelated proteins(P<0.01). Moreover, celastrol inhibited epithelial-mesenchymal transition(EMT) by the blockade of TGF-β/Smad and Jagged/Notch signaling pathways.CONCLUSION: Our study demonstrates that celastrol could inhibit TGF-β2-induced lens fibrosis and raises the possibility that celastrol could be a potential novel drug in prevention and treatment of fibrotic cataract.

Celastrol Induces Apoptosis and Autophagy via the AKT/mTOR Signaling Pathway in the Pituitary ACTH-secreting Adenoma Cells

Objective Pituitary adrenocorticotropic hormone(ACTH)-secreting adenoma is a relatively intractable endocrine adenoma that can cause a range of severe metabolic disorders and pathological changes involving multiple systems.Previous studies have shown that celastrol has antitumor effects on a variety of tumor cells via the AKT/mTOR signaling.However,whether celastrol has pronounced antitumor effects on pituitary ACTH-secreting adenoma is unclear.This study aimed to identify a new effective therapeutic drug for pituitary ACTH-secreting adenoma.Methods Mouse pituitary ACTH-secreting adenoma cells(AtT20 cells)were used as an experimental model in vitro and to establish a xenograft tumor model in mice.Cells and animals were administered doses of celastrol at various levels.The effects of celastrol on cell viability,migration,apoptosis and autophagy were then examined.Finally,the potential involvement of AKT/mTOR signaling in celastrol’s mechanism was assessed.Results Celastrol inhibited the proliferation and migration of pituitary adenoma cells in a time-and concentration-dependent manner.It blocked AtT20 cells in the G0/G1 phase,and induced apoptosis and autophagy by downregulating the AKT/mTOR signaling pathway.Similar results were obtained in mice.Conclusion Celastrol exerts potent antitumor effects on ACTH-secreting adenoma by downregulating the AKT/mTOR signaling in vitro and in vivo.

Celastrol inhibits laser-induced choroidal neovascularization by decreasing VEGF induced proliferation and migration

AIM:To evaluate celastrol's effect on choroidal neovascularization(CNV).METHODS:In this study,neovascular formation in vitro(tube formation and aortic ring culture)and in vivo(laser induced neovascular in mice)was treated with celastrol to evaluate this natural compound's impact on CNV.Western blot was applied to explore the possible mechanism for it.For in vitro assay,triplicate for each group was repeated at least three times.For in vivo assay,each group contains 5 mice.RESULTS:Celastrol supressed tube formation and aortic ring sprout neovascularization.In vitro assay exhibited that celastrol inhibiting vascular endothelial growth factor(VEGF)-induced proliferation and migration of human umbilical vein endothelial cells and human choroidal endothelial cells,and by blocking VEGF signaling.Furthermore,intraperitoneal administration of celastrol significantly reduced the area of laser-induced CNV in an in vivo mouse model.By day 14,the area of CNV had decreased by 49.15%and 80.26%in the 0.1 mg/kg celastrol-treated group(n=5)and in the 0.5 mg/kg celastrol treated group(n=5),respectively,compared to the vehicle-treated group(n=5).CONCLUSION:Celastrol inhibits CNV by inhibiting VEGF-induced proliferation and migration of vascular endothelial cells,indicating that celastrol is a potent,natural therapeutic compound for the prevention of CNV.

Celastrol Protects TGF-β1-induced Endothelial-mesenchymal Transition

The endothelial-to-mesenchymal transition（End MT） in endothelial cells contributes to the development of cardiac fibrosis,ultimately leading to cardiac remodeling.In this study,the effects and molecular mechanisms of celastrol（CEL） on transforming growth factor-β1（TGF-β1）-induced End MT in human umbilical vein endothelial（HUVEC-12） cells were investigated.The presented data demonstrated that CEL significantly blocked the morphology change of HUVEC-12 cells induced by TGF-β1 without cell cytotoxicity.In accordance with these findings,CEL blocked TGF-β1-induced EndM T as evidenced by the inhibition of the mesenchymal markers,including collagen Ⅰ,Ⅲ,α-SMA,fibronectin m RNA expression,and the increase in the m RNA expression of endothelial cell marker CD31.These changes were also confirmed by double immunofluorescence staining of CD31 and vimentin.The in vitro scratch assay showed that CEL inhibited the migration capacity of the transitioned endothelial cells induced by TGF-β1.Further experiments showed that the beneficial effect of CEL on blocking the End MT in HUVEC-12 cells was associated with the suppression of the TGF-β1/Smads signalling pathway,which was also confirmed by the inhibition of its downstream transcription factor snail1,twist1,twist2,ZEB1 and ZEB2.These results indicate that CEL blocks TGF-β1-induced End MT through TGF-β1/Smads signalling pathway and suggest that it may be a feasible therapy for cardiac fibrosis diseases.

Celastrol alleviates arthritis by modulating the inflammatory activities of neutrophils

Objective:Neutrophils play an important role in the pathogenesis of rheumatoid arthritis (RA).In this study,we used the adjuvant-induced arthritis murine model to evaluate the efficacy of celastrol on neutrophil-mediated inflammation in RA.Methods:Freund's complete adjuvant-induced arthritis was used as the murine model of RA.Celastrol was intraperitoneally administrated daily after onset of the disease.The joint diameter and inflammatory score were evaluated daily during the treatment period.Myeloperoxidase (MPO) and neutrophil elastase (NE) activities were evaluated by immunohistochemical analyses.Quantitative PCR and enzyme-linked immunoabsorbent assay were used to quantify the expression of cytokines.The expression of apoptosis-related proteins Bcl-2,Bax and caspase-3 were evaluated by western blot.Results:Celastrol suppressed inflammation in joints of arthritic mice and diminished the expression of MPO and NE in the joint tissue.Celastrol significantly inhibited the expression of TNFα and IL-6 induced by LPS in neutrophils in a dose-dependent manner in vitro.Moreover,celastrol induced apoptosis of LPS-stimulated neutrophils by increasing the expression of Bax and cleaved caspase-3 while decreasing Bcl-2 expression.Conclusion:Our findings show that celastrol significantly alleviates murine arthritis by modulating the inflammatory activities of neutrophils.These results indicate that celastrol could serve as an alternative or adjunct modality for the treatment of RA.

Study of Celastrol on Akt Signaling Pathway and Its Roles in the Apoptosis of K562 Cells

The purpose Celastrol, the main active compound of the Celastrus genus plants, belonging to Celastraceae, has recently marked antitumour potency on solid tumours of various derivations, Methods: We demonstrate here that Celastrol also present powerful antileukaemic potency through both growth arrest and apoptosis induction in K562 cells, which was accompanied by typical apoptotic morphological and sharp decreased expression of phosphorylation level of Caspase family members and Akt signaling pathway related proteins were determined by western blot before and after celastrol treatment, and further the effect of AKT signaling pathway on celastrol-induced-apoptosis was analyzed. However, in vitro treatment with Celastrol resulted in significantly reduced expression of phophorylation of Akt, Survivin and Bcl-2 significantly in K562 cells. Results: 25 nmol/L WORT (PI3K-Akt inhibitor) can significantly augmented cell apoptosis induced by Celastrol in K562 cells in dose-dependent manner, Moreover, most Caspase3,8,6 were activated in K562 cells during Celastrol treatment, 50 μmol/Lz-VAD-fmk (Caspase inhibitor) can to enhance the apoptosis induced by Celastrol. Discussion: These results suggest that the fact that Akt signaling pathway might act as new targets of Celastrol, correlates well with the sensitivity to Celastrol, as well as the rate of apoptosis induced by Celastrol, Mechanisms that regulate Akt signaling pathway may be provide novel opportunities for drug development.

Identification of Genes Involved in Celastrol Biosynthesis by Comparative Transcriptome Analysis in Tripterygium wilfordii

Tripterygium wilfordii has been renowned mostly because of the anticancer effects of its root extracts,which is partly ascribed to the presence of celastrol,a pentacyclic triterpenoid,as one of the main active components.Celastrol also has recently been reported as an effective prodrug in the treatment of obesity.Despite the promising activities,the pathway leading to celastrol biosynthesis,especially cytochrome P450(CYP)enzyme(s)that occur in its downstream steps,are largely unknown.This study conducted a comparative analysis of the T.wilfordii transcriptome derived from its root and leaf tissues.Differential gene expression analysis identified a number of root-specific CYP genes.Further phylogenetic analysis suggested specific family members of CYPs that may participate in the late steps during celastrol biosynthesis.Root-specific transcription factors(TFs)that may play regulatory roles in celastrol biosynthesis were also discussed.This genetic resource will aid in isolating the celastrol biosynthetic genes as well as engineering the celastrol biosynthesis pathway.

Study on Extraction Techniques of Celastrol from Celastrus orbiculatus Thunb.

[Objectives]This study was conducted to investigate the extraction technology of celastrol from Celastrus orbiculatus Thunb.[Methods]Solvent ultrasonic extraction was selected,and with the content of celastrol as the evaluation index,the effects of different solvents,extraction time,temperatures and material-to-liquid ratios on the extraction rate of celastrol were investigated by single factor and orthogonal experiments.[Results]The optimal extraction conditions were as follows:a solvent ratio of petroleum ether to ethyl acetate at 1∶1,a ratio of solvent to material at 10∶1(v/w),extraction time of 30 min,and an extraction temperature at 30℃.[Conclusions]This method has high extraction rate,and is simple and feasible.

TRAIL and Celastrol Combinational Treatment Suppresses Proliferation, Migration, and Invasion of Human Glioblastoma Cells via Targeting Wnt/β-catenin Signaling Pathway

Objective To investigate the mechanistic basis for the anti-proliferation and anti-invasion effect of tumor necrosis factor-related apoptosis-induced ligand(TRAIL)and celastrol combination treatment(TCCT)in glioblastoma cells.Methods Cell counting kit-8 was used to detect the effects of different concentrations of celastrol(0-16µmol/L)and TRAIL(0-500 ng/mL)on the cell viability of glioblastoma cells.U87 cells were randomly divided into 4 groups,namely control,TRAIL(TRAIL 100 ng/mL),Cel(celastrol 0.5µmol/L)and TCCT(TRAIL 100 ng/mL+celastrol 0.5µmol/L).Cell proliferation,migration,and invasion were detected by colony formation,wound healing,and Transwell assays,respectively.Quantitative reverse transcription polymerase chain reaction and Western blotting were performed to assess the levels of epithelial-mesenchymal transition(EMT)markers(zona occludens,N-cadherin,vimentin,zinc finger E-box-binding homeobox,Slug,and β-catenin).Wnt pathway was activated by lithium chloride(LiCl,20 mol/L)and the mechanism for action of TCCT was explored.Results Celastrol and TRAIL synergistically inhibited the proliferation,migration,invasion,and EMT of U87 cells(P<0.01).TCCT up-regulated the expression of GSK-3β and down-regulated the expression of β-catenin and its associated proteins(P<0.05 or P<0.01),including c-Myc,Cyclin-D1,and matrix metalloproteinase(MMP)-2.In addition,LiCl,an activator of the Wnt signaling pathway,restored the inhibitory effects of TCCT on the expression of β-catenin and its downstream genes,as well as the migration and invasion of glioblastoma cells(P<0.05 or P<0.01).Conclusions Celastrol and TRAIL can synergistically suppress glioblastoma cell migration,invasion,and EMT,potentially through inhibition of Wnt/β-catenin pathway.This underlies a novel mechanism of action for TCCT as an effective therapy for glioblastoma.

Ferroptosis inhibitors reduce celastrol toxicity and preserve its insulin sensitizing effects in insulin resistant HepG2 cells

Objective:Research has shown that celastrol can effectively treat a variety of diseases,yet when passing a certain dosage threshold,celastrol becomes toxic,causing complications such as liver and kidney damage and erythrocytopenia,among others.With this dichotomy in mind,it is extremely important to find ways to preserve celastrol’s efficacy while reducing or preventing its toxicity.Methods:In this study,insulin-resistant Hep G2(IR-Hep G2)cells were prepared using palmitic acid and used for in vitro experiments.IR-Hep G2 cells were treated with celastrol alone or in combination with Nacetylcysteine(NAC)or ferrostatin-1(Fer-1)for 12,24 or 48 h,at a range of doses.Cell counting kit-8assay,Western blotting,quantitative reverse transcription-polymerase chain reaction,glucose consumption assessment,and flow cytometry were performed to measure celastrol’s cytotoxicity and whether the cell death was linked to ferroptosis.Results:Celastrol treatment increased lipid oxidation and decreased expression of anti-ferroptosis proteins in IR-Hep G2 cells.Celastrol downregulated glutathione peroxidase 4(GPX4)m RNA.Molecular docking models predicted that solute carrier family 7 member 11(SLC7A11)and GPX4 were covalently bound by celastrol.Importantly,we found for the first time that the application of ferroptosis inhibitors(especially NAC)was able to reduce celastrol’s toxicity while preserving its ability to improve insulin sensitivity in IR-Hep G2 cells.Conclusion:One potential mechanism of celastrol’s cytotoxicity is the induction of ferroptosis,which can be alleviated by treatment with ferroptosis inhibitors.These findings provide a new strategy to block celastrol’s toxicity while preserving its therapeutic effects.

Activation of NRF2 by celastrol increases antioxidant functions and prevents the progression of osteoarthritis in mice

Excessive oxidative stress impairs cartilage matrix metabolism balance,significantly contributing to osteoarthritis(OA)development.Celastrol(CSL),a drug derived from Tripterygium wilfordii,has recognized applications in the treatment of cancer and immune system disorders,yet its antioxidative stress mechanisms in OA remain underexplored.This study aimed to substantiate CSL’s chondroprotective effects and unravel its underlying mechanisms.We investigated CSL’s impact on chondrocytes under both normal and inflammatory conditions.In vitro,CSL mitigated interleukin(IL)-1β-induced activation of proteinases and promoted cartilage extracellular matrix(ECM)synthesis.In vivo,intra-articular injection of CSL ameliorated cartilage degeneration and mitigated subchondral bone lesions in OA mice.Mechanistically,it was found that inhibiting nuclear factor erythroid 2-related factor 2(NRF2)abrogated CSL-mediated antioxidative functions and exacerbated the progression of OA.This study is the first to elucidate the role of CSL in the treatment of OA through the activation of NRF2,offering a novel therapeutic avenue for arthritis therapy.