Identification and validation of novel biomarkers for cold-dampness syndrome of rheumatoid arthritis based on integration of multiple bioinformatics methods / 中国中药杂志

This study aims to identify the novel biomarkers of cold-dampness syndrome(RA-Cold) of rheumatoid arthritis(RA) by gene set enrichment analysis(GSEA), weighted gene correlation network analysis(WGCNA), and clinical validation. Firstly, transcriptome sequencing was carried out for the whole blood samples from RA-Cold patients, RA patients with other traditional Chinese medicine(TCM) syndromes, and healthy volunteers. The differentially expressed gene(DEG) sets of RA-Cold were screened by comparison with the RA patients with other TCM syndromes and healthy volunteers. Then, GSEA and WGCNA were carried out to screen the key DEGs as candidate biomarkers for RA-Cold. Experimentally, the expression levels of the candidate biomarkers were determined by RT-qPCR for an independent clinical cohort(not less than 10 cases/group), and the clinical efficacy of the candidates was assessed using the receiver operating characteristic(ROC) curve. The results showed that 3 601 DEGs associated with RA-Cold were obtained, including 106 up-regulated genes and 3 495 down-regulated genes. The DEGs of RA-Cold were mainly enriched in the pathways associated with inflammation-immunity regulation, hormone regulation, substance and energy metabolism, cell function regulation, and synovial pannus formation. GSEA and WGCNA showed that recombinant proteasome 26S subunit, ATPase 2(PSMC2), which ranked in the top 50% in terms of coefficient of variation, representativeness of pathway, and biological modules, was a candidate biomarker of RA-Cold. Furthermore, the validation results based on the clinical independent sample set showed that the F1 value, specificity, accuracy, and precision of PSMC2 for RA-Cold were 70.3%, 61.9%, 64.5%, and 81.3%, respectively, and the area under the curve(AUC) value was 0.96. In summary, this study employed the "GSEA-WGCNA-validation" integrated strategy to identify novel biomarkers of RA-Cold, which helped to improve the TCM clinical diagnosis and treatment of core syndromes in RA and provided an experimental basis for TCM syndrome differentiation.

Investigation on the pharmacological mechanisms of Shirebi granules in treating gouty arthritis with damp-heat syndrome based on crosstalk of Wnt/β-catenin signaling / 药学学报

Gouty arthritis is a type of metabolic rheumatic disease caused by autoimmune abnormalities. Currently, the use of Western medicine in the clinical treatment of gouty arthritis has been associated with a high risk of adverse reactions. Therefore, there is a growing interest in exploring therapeutic drugs from traditional Chinese medicine as a potential alternative. According to the theory of traditional Chinese medicine, gouty arthritis has been classified as damp-heat arthralgia syndrome. Shirebi granules has been found to have good clinical efficacy in treating gouty arthritis. However, its underlying pharmacological mechanisms remain unclear. To address this problem, the study first established the interaction network of candidate targets for Shirebi granules, which is used to treat damp-heat syndrome of gouty arthritis. Then, the key candidate targets of Shirebi granules for treating gouty arthritis with damp-heat syndrome were screened by calculating the topological features of the network nodes. Then, the functional mining of the key candidate targets revealed that the candidate targets of Shirebi granules may intervene in the biological process of inflammatory response and lipid metabolism through the crosstalk of Wnt/β-catenin signaling. To verify the effectiveness of Shirebi granules in treating gouty arthritis with damp-heat syndrome, a rat model was established. The results demonstrated that the granules significantly improved the severity of arthritis in rats with this condition, reduced joint inflammation, gait score, swelling index, increased mechanical pain threshold (P < 0.05), and reduced the content of serum inflammatory factors IL-1β, IL-6, and TNF-α in gouty arthritis rats with damp-heat syndrome (P < 0.01) gouty. It was also found that Shirebi granules effectively alleviated the symptoms of dampness heat syndrome such as local joint fever and dry mouth by reducing the temperature of the joints in acute gouty arthritis with damp-heat syndrome (AD) rats, increasing the threshold of heat pain, increasing water intake (P < 0.01), and inhibiting abnormal changes in the content of fatty acid oxidation related enzymes (P < 0.01). Western blot analysis showed that Shirebi granules increased the protein expression levels of Wnt and β-catenin (P < 0.01) while decreasing the protein expression of p65, p-p65 and PPARγ (P < 0.01) in rats with gouty arthritis and damp-heat syndrome. The results showed that Shirebi granules may reverse the "inflammation-immune" imbalance and lipid metabolism disorder by regulating the crosstalk of Wnt/β-catenin signaling, and play a role in alleviating the severity of the disease. This study provides a methodological reference for elucidating the pharmacological mechanisms of traditional Chinese medicine formulas. It also presents research ideas for the appropriate clinical use of Chinese patent medicines and the development of new clinical drugs for gouty arthritis therapy. The animal welfare and experiment procedures of this study were performed in accordance with the regulations of the Experimental Animal Ethics Committee of Experimental Research Center, China Academy of Chinese Medical Sciences (grant No. ERCCACMS11-2302-08).

Exploring biological connotation of blood stasis syndrome of rheumatoid arthritis and establishment of improved animal models based on syndrome-symptom mapping / 药学学报

Blood stasis syndrome is one of the core clinical syndrome of rheumatoid arthritis (RA), but the biological connotation of this syndrome is not clear, and there is a lack of disease improved animal models that match the characteristics of this disease and syndrome. The aim of this study was to screen the candidate biomarker gene set of blood stasis syndrome of RA, reveal the biological connotation of this syndrome, and explore and evaluate the preparation method of the improved animal model based on the characteristics of "disease-syndrome-symptom". The study was approved by the ethics committee of Guang'anmen Hospital, Chinese Academy of Traditional Chinese Medicine (No. 2019-073-KY-01) and the First Affiliated Hospital of Tianjin University of Traditional Chinese Medicine (No. TYLL2021[K]018), and the study subjects gave their informed consent. Animal welfare and experimental procedures followed the regulations of the Experimental Animal Ethics Committee of the Chinese Academy of Traditional Chinese Medicine (No. IBTCMCACMS21-2207-01). The whole blood samples were collected clinically from RA patients with blood stasis syndrome (3 cases) or other syndromes (7 types, 3 cases/type), and healthy volunteers (4 cases), and then transcriptome sequencing, KEGG, gene set enrichment analysis (GSEA) and weighted correlation network analysis (WGCNA) analysis were performed. 126 pivotal genes were screened, and their functional annotation results were significantly enriched in "immune-inflammation" related pathways and lipid metabolism regulation (sphingolipids, ether lipid metabolism and steroid biosynthesis). Syndrome-symptom mapping of hub gene set to the TCM primary and secondary symptoms, Western phenotypic symptoms and pathological links showed that joint tingling, abnormal joint morphology, petechiae and abnormal blood circulation are representative of blood stasis syndrome of RA. The results of the improved animal model showed that the rats in the collagen-induced arthritis + adrenaline hydrochloride (CIA+Adr) 3 model group had increased blood rheology, coagulation, platelet function and endothelial function abnormalities compared with the CIA-alone model group, suggesting that the rats with blood stasis syndrome of RA may be in a state of "blood stasis". The results of the study can help to advance the objective study of the evidence of blood stasis syndrome in RA, and provide new ideas for the establishment of an animal model that reflects the clinical characteristics of the disease and syndrome.

Biological connotation of four traditional Chinese medicine syndromes of rheumatoid arthritis based on "disease-syndrome-symptom" association network / 中国中药杂志

The present study explored the biological connotation of traditional Chinese medicine(TCM) syndromes of rheumatoid arthritis(RA) from the "disease-syndrome-symptom" association network. RA patients with four TCM syndromes(dampness-heat obstruction, phlegm-stasis obstruction, Qi-blood deficiency, and liver and kidney deficiency), three for each type, were assigned as the RA TCM syndrome group, and three healthy volunteers as the normal control group. The differential gene sets of four syndromes were screened out through transcriptome expression profiling and bioinformatics mining. The relevant gene sets of syndrome-related clinical symptoms were collected from TCMIP v2.0(http://www.tcmip.cn/). The "disease-syndrome-symptom" association networks of four RA syndromes were established by using the intersection genes of syndrome-related differential genes and symptom-related genes, and the key network target genes of each syndrome were screened out and the corresponding biological functions were mined through topological feature calculation and enrichment analysis. The genes associated with clinical symptoms such as vasculitis, joint pain, and fever in the damp-heat obstruction syndrome ranked the top, and the key network target genes of this syndrome were most significantly enriched in the pathways related to material and energy metabolism and thermal reaction biological processes. The clinical symptom-related genes of the phlegm-stasis obstruction syndrome were most significantly enriched in the pathways related to "immunity-inflammation", nervous system regulation, and sensory response. The clinical symptoms such as hypoglycemia, hypotension, weight loss, palpitation, and arrhythmia in Qi-blood deficiency syndrome were predominant, and its key network target genes were most significantly enriched in the pathways related to the nervous system and "immunity-inflammation" response. The abnormal symptoms in the liver and kidney in the liver and kidney deficiency syndrome were commonly seen, and its key network target genes were most significantly enriched in the "immunity-inflammation" regulatory pathways, and liver and kidney development and metabolic response. In conclusion, the differences and connections of the biological basis between different TCM syndromes of RA are in line with the theoretical interpretation of TCM on the etiology and pathogenesis of RA. This study summarized the objective essence of syndromes to a certain extent from the "disease-syndrome-symptom" association network and is expected to provide a theoretical basis for the discovery of serum biomarkers of RA syndromes.

Meta-analysis of RCT studies on clinical efficacy of single administration of Tripterygium Glycosides Tablets or combined administration with methotrexate against rheumatoid arthritis / 中国中药杂志

To evaluate the clinical efficacy of single administration of Tripterygium Glycosides Tablets(TGT) or combined administration with methotrexate(MTX) against rheumatoid arthritis(RA) based on American College of Rheumatology(ACR) efficacy standard. Six databases, namely CNKI, WanFang, VIP, PubMed, Embase and Cochrane Library, were retrieved for randomized controlled trials(RCT), and clinical trials were screened out according to the preset inclusion and exclusion criteria. Then, the study quality was evaluated by the risk assessment tools. Data extraction and analysis were performed by using RevMan 5.3 software for Meta-analysis. Sensitivity analysis and publication bias analysis were made to test the stability and reliability of results. Until December 2018, a total of 1 709 articles were obtained, and finally 10 clinical RCT studies with a total of 1 184 patients were included. As a result, the single administration of TGT showed a significantly better ACR efficiency(RR=1.31, 95%CI[1.15, 1.49], P<0.000 1) than methotrexate(MTX). The combined administration of TGT and MTX showed a significantly better ACR efficiency(RR=1.28, 95%CI[1.20, 1.38], P<0.000 01) than the single administration of MTX. In conclusion, the single administration of TGT and the combined administration of TGT and MTX were more effective in achieving ACR20, ACR50, ACR70 compliance than the single administration of MTX. Further validations based on more RCT studies with high-quality are required.

Systematic reviews of effects of Tripterygium Glycosides Tablets on pro-inflammatory factors in rheumatoid arthritis / 中国中药杂志

To systematically evaluate the effects of Tripterygium Glycosides Tablets alone or in combination with methotrexate(MTX) and leflunomide(LEF) on the levels of pro-inflammatory cytokines in patients or animal models with rheumatoid arthritis(RA), and to provide reference for clinical application and related basic research, this study systematically searched databases of CNKI, VIP, WanFang, PubMed, Embase and Cochrane Library, collected relevant clinical or animal experimental studies, used risk assessment tools to evaluate the quality of research, and used Revman 5.3 software to conduct Meta-analysis or descriptive analysis of the outcome indicators included in the literatures. Of the 1 709 papers retrieved, 3 clinical studies and 12 animal experiments were included. The results showed that compared with MTX alone, Tripterygium Glycosides Tablets combined with MTX could further reduce the expression levels of peripheral blood TNF-α(SMD=-8.88,95%CI[-10.77,-6.99],P<0.000 01),IL-1β(P<0.000 01) and IL-6(SMD=-8.63, 95%CI[-10.57,-6.69], P<0.000 01) in RA patients. Compared with LEF alone, the combination of Tripterygium Glycosides Tablets and LEF could not further reduce the expression levels of TNF-α(P=0.20), IL-1β(P=0.17), IL-6(P=0.31). In RA animal model, compared with model group, Tripterygium Glycosides Tablets could reduce the expression levels of peripheral blood IL-1β(SMD=-6.29,95%CI[-9.64,-2.93],P<0.000 2)in peripheral blood(SMD=-1.39,95%CI[-1.77,-1.02],P<0.000 01), joint fluid(P<0.000 01) and paw plasma(P=0.02), and also reduce the expression levels of TNF-α in RA animal model group. Compared with MTX alone, Tripterygium Glycosides Tablets alone reduced the same levels of TNF-α(P=0.42) and IL-6(P=0.08) in joint fluid, while Tripterygium Glycosides Tablets combined with MTX could further reduce the levels of IL-6(P=0.000 1) in joint fluid; compared with LEF alone, Tripterygium Glycosides Tablets have the similar effects on reducing the expression levels of peripheral blood TNF-α(P=0.16), IL-1β(P=0.32), IL-6(P=0.12), while Tripterygium Glycosides Tablets combined with LEF could further reduce the expression levels of TNF-α(P=0.008), IL-1β(P=0.02), IL-6(P<0.000 1) in peripheral blood. Therefore, Tripterygium Glycosides Tablets combined with MTX could further reduce the expression levels of pro-inflammatory cytokines in peripheral blood of RA patients. Tripterygium Glycosides Tablets alone could reduce the expression levels of pro-inflammatory cytokines in peripheral blood and local joint of RA animal models. Tripterygium Glycosides Tablets combined with MTX or LEF could further reduce the express levels of pro-inflammatory cytokines in peripheral blood of RA animal models. Due to the limitation of literature, this conclusion needs to be further validated.

Investigation on Anti-liver Cancer Potential and Compatibility Characteristics of Fufang Biejia Ruangan Pian from Network Perspective / 中国实验方剂学杂志

Objective:To explore the anti-liver cancer potential of Fufang Biejia Ruangan Pian （FBRP） and its compatibility characteristics from a network perspective， so as to provide a theoretical basis for the clinical repositioning of FBRP. Method:Three self-pairs of cancer and para-cancerous tissue samples were collected from three patients with primary liver cancer， and the whole genome expression profiling chip was used to detect the differential genes related to the development and progression of liver cancer. After collecting the phenotype-related genes and the candidate targets of the corresponding prescriptions of FBRP from The Encyclopedia of Traditional Chinese Medicine （ETCM） and Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine （TCMIP） V2.0， the "differentially expressed genes related to liver cancer development-candidate targets of FBRP efficacy substance group" interaction network was constructed according to the interaction information between the above-mentioned differentially expressed genes related to liver cancer and the candidate targets of the FBRP efficacy group， and then the major network nodes were screened. After that， the enrichment analysis of the pathway was performed in order to explore the biological basis of various pharmacological efficacy groups of FBRP， including Xiaozheng Sanjie group （Trionycis Carapax and Curcumae Rhizoma）， Buxue Huoxue group （Paeoniae Radix Rubra， Angelicae Sinensis Radix and Notoginseng Radix et Rhizoma）， Yiqi Jianpi group （Codonopsis Radix and Astragali Radix）， Yuyin Yanggan group （Placenta Hominis and Cordyceps） and Qingre Jiedu group （Isatidis Radix and Forsythiae Fructus）. Result:The major network targets of the five efficacy groups may be involved into several common pathways but also associated with some special pathological processes. Those common pathways mainly contained the regulation of nervous system， the balance of immune-inflammatory system， the regulation of energy metabolism of various substances and cancer-related pathways， while the point was also reflected by the follows：①The regulating effects of Xiaozheng Sanjie group and Yiqi Jianpi group were summarized as promoting Qi circulation and relieving depression and replenishing Qi-blood， benefiting spirit. Buxue Huoxue group may also participate in the regulation of promoting Qi circulation and relieving depression and Yuyin Yanggan group may participate in the regulation of replenishing Qi-blood and benefiting spirit. ②The regulatory effects of the Xiaozheng Sanjie group and the Yuyin Yanggan group were summarized as essence， Qi and blood supplement. Buxue Huoxue group focused on the improvement of the immune-circulatory system. Qingre Jiedu group mainly regulated the balance of immune-inflammatory system by acting on T cell receptor signaling pathway. ③Yiqi Jianpi group was demonstrated to show the effects on various material and energy metabolisms. Yuyin Yanggan group exerted effects on lipid metabolism， carbohydrate metabolism， protein metabolism and hormone metabolism. Qingre Jiedu group was also involved into metabolism of nucleotide and hormone. ④In the aspect of alleviating the pathological changes of cancer， the regulatory effects of the five efficacy groups on cell cycle and other functions could be summarized as dispelling pathogenic factors. ⑤The whole prescription focused on the anti-liver cancer potential of FBRP as a whole， while each efficacy group emphasized that each efficacy group had its own functional characteristics. The two network analysis models complemented and verified each other. Conclusion:FBRP has the anti-hepatoma potential. By revealing the biological connotation of its efficacy and the rationality of the compatibility， the regulation mechanism of FBRP to correct the imbalance network of inflammation and cancer in liver is clarified， which can provide the possibility and biological basis for FBRP to increase the clinical indications for the prevention and treatment of liver cancer.

Current research analysis and prospects on sensitization effect of artesunate on anti-cancer radiotherapy and chemotherapy / 中国中药杂志

The wide application of artemisinins in the treatment of multiple cancers reflects the advantages of traditional Chinese medicine used in this field. The existing basic and clinical studies have revealed that artesunate can effectively suppress the malignant progression of breast cancer,colon cancer,leukemia,melanoma,ovarian cancer,prostate cancer,kidney cancer and various tumors in central nervous system. The pharmacological mechanisms of artesunate against cancers are reflected in many aspects,such as inhibiting tumor cell proliferation,invasion and metastasis,inducing tumor cell apoptosis and autophagy,regulating cell signal transduction and inhibiting tumor angiogenesis. Meanwhile,growing experimental evidences have indicated that artesunate has been used for the sensitization of radiotherapy with X-ray,β-ray,γ-ray and~(60)Co γ-ray,as well as chemotherapy with cisplatin,carboplatin and doxorubicin.This review collected basic and clinical studies on the sensitization effect of artesunate on anti-cancer radiotherapy and chemotherapy published on PubMed and CNKI during April 2000 and February 2019,and summarized the clinical positioning and application of artesunate,with the aim to provide a more comprehensive explanation on the sensitization effect of artesunate on anti-cancer radiotherapy and chemotherapy,and offer the inspiration and ideas for the development of radiotherapy and chemotherapy sensitizers,as well as cancer resistance reversal agents.

An exploration into the therapeutic effects and molecular mechanisms of paeoniflorin in the treatment of adjuvant-induced arthritis rats by a network pharmacology-based research strategy / 药学学报

Paeoniflorin (PAE), the major active compounds of Chinese herbs Radix Paeoniae Alba andChinese patent drug "Total Glucosides of Paeony Capsules", which is effective in the treatment of rheumatoid arthritis (RA), exerted multi-pharmacological activities, such as anti-inflammatory, immune-regulatory, etc. However, its potential action mechanisms remain unclear. Herein, we predicted the putative targets of Radix Paeoniae Alba and constructed an interaction network of putative targets of Radix Paeoniae Alba and known RA-related genes. A list of key putative targets was identified by calculating their topological features (degree, node betweenness and closeness) in the above pharmacological network. Importantly, pathway enrichment analysis revealed that these key putative targets were significantly enriched in several RA-related pathways, including cartilage damage-related IL1B-TNF-TLR2-JUN-MMP1-MMP3 signaling pathway. Further molecular docking simulation showed that PAE, the major active compounds of Radix Paeoniae Alba, has strong binding affinity with MMP1 and MMP3 proteins. Next, in vivo experiments based on the adjuvant-induced arthritis (AIA) animal models showed that PAE significantly alleviated the disease severity and the syndromes of severe redness or swelling in hind limbs of AIA rats, including decreasing the arthritis score, the diameter of the limbs, and elevating body weight and pain thresholds (all P<0.05). ELISA assay indicated that PAE obviously suppressed the abnormal up-regulation of serum inflammatory factors including IL-1β, TNF-α, IL-6, IL-17 and IFN-γ in AIA rats (all P<0.001). Western blot analysis found that PAE simultaneously modulated the abnormal up-regulation of MMP1 and MMP3 proteins in the ankle tissues of AIA rats (all P<0.001) (all procedures in the current study were performed in accordance with the ethical standards of the Center for Laboratory Animal Care, China Academy of Chinese Medical Sciences). In conclusion, PAE alleviated the cartilage damage and disease severity in the progressive process of RA via regulating the IL1B-TNF-TLR2-JUN-MMP1-MMP3 pathway. This study provided the theoretical basis of the PAE for its immune-regulatory effects, and as well provided references for the action mechanism study of extract compounds of Chinese herbs.

Clinical symptoms effect of Tripterygium Glycosides Tablets alone or combined with methotrexate in treatment of rheumatoid arthritis: a Meta-analysis / 中国中药杂志

To systematically review the improvement effects of Tripterygium Glycosides Tables( TGT) alone or in combination with methotrexate( MTX) on the clinical signs and symptoms of rheumatoid arthritis( RA),and provide a basis for the rational use of TGT in clinic,in the current study,six literature databases including CNKI,Wan Fang,VIP,PubMed,EMbase,and Cochrane Library,were systematically searched,according to the inclusion and exclusion criteria. Review Manager 5.3 software was used to input the literatures,and we assessed the risk bias on the level of outcome indicators for each included literature. A total of 18 literatures were included,and the classification results showed that: compared with MTX,TGT alone can reduce the number of joint swelling( MD =0. 18,95%CI[-1.06,1.42],P = 0.78) and joint tenderness( MD =-0.06,95% CI[-1.69,1.56],P = 0.94) in RA patients with the same effect as MTX. In terms of drug combination,TGT combined with MTX had an advantage over MTX alone in lessening the morning stiffness time( MD = 18. 24,95% CI[12. 64,23. 84],P < 0. 000 01) of RA,joint tenderness( MD = 2. 65,95% CI[1. 85,3. 44],P<0.000 01) and joint swelling( MD = 3.01,95% CI[2.09,3.39],P< 0.000 01). In conclusion,this Meta-analysis suggest that TGT alone was superior to MTX in improving joint swelling and tenderness in RA patients,TGT combined with MTX may improve the clinical manifestation of RA patients better than MTX alone.

Meta-analysis of laboratory index of Tripterygium Glycosides Tablets in treatment of rheumatoid arthritis / 中国中药杂志

The aim of this study was to systematically evaluate the clinical efficacy of Tripterysium Glycosides Tablets( TGT) alone or in combination with methotrexate( MTX) in the treatment of rheumatoid arthritis( RA) based on the laboratory index criteria and to provide a basis for the clinical application of TGT against RA. Six databases including CNKI,Wan Fang,VIP,PubMed,EMbase and Cochrane were retrieved for randomized controlled trials( RCT) about TGT alone or combination with MTX in the treatment of RA.Then risk assessment tools were used for quality evaluation of the studies,and data extraction and analysis were conducted by using Rev Man 5.3 software for Meta-analysis. A total of 1 709 articles were retrieved,and finally 25 studies were included,with a total sample size of 2 507 cases. Meta-analysis results showed that between TGT alone and TGT alone,MDESR=-2. 66,95%CI[-8.17,2.86],P = 0.35; MDCRP=-2.38,95%CI[-9.01,4.24],P = 0.48; between TGT combined with MTX and MTX alone,MDESR= 8.74,95%CI[6.72,10.76],P<0.000 01; MDCRP= 5.37,95%CI[3.71,7.03],P<0.000 01; SMDRF= 1.05,95%CI[0.51,1.60],P = 0.000 1.The effect of TGT on decreasing CRP and ESR in RA patients was similar to the MTX. In addition,TGT combined with MTX were more effective in decreasing CRP,ESR,RF than MTX alone. However,due to the potential bias in the included studies,more and high-quality randomized controlled trials would be needed to improve the level of evidence.

Dexamethasone-induced apoptosis of murine MIN6 pancreatic beta-cells and its effect on AKT phosphorylation / 药学学报

This study is to investigate the effect of dexamethasone on cell apoptosis of murine MIN6 pancreatic beta-cells, and to investigate the mechanism of dexamethasone-dependent cell apoptosis. The cell apoptosis model was established by choosing the murine MIN6 pancreatic beta-cells, which was cultured in vitro and induced by dexamethasone. The morphology of the cell apoptosis was observed through fluorescence microscopic analysis after Hochest/PI staining and flow cytometric assay after Annexin-V/PI staining. The expression of caspase-3 was detected with caspase-3 activity assay kit. The expressions of Cyt-c, Bcl-2, Bax, AKT and p-AKT were observed with Western blotting. The results indicated that after exposure to dexamethasone at a concentration ranging from 50-800 nmol x L(-1) for 48 h, the percentage of cell apoptosis was significantly increased with the concentration over 100 nmol x L(-1) of dexamethasone; after exposure to dexamethasone (100 nmol x L(-1)) for 72 h, the activity of caspase-3 increased significantly; after exposure to dexamethasone at a concentration ranging from 50-800 nmol x L(-1) for 48 h, the expression of Cyt-c increased, Bcl-2 and AKT phosphorylation decreased while Bax and T-AKT remained unchanged. It could be concluded that the effect of dexamethasone on murine MIN6 pancreatic beta-cells apoptosis is significant. The mechanism of dexamethasone-dependent cell apoptosis is probably related to down regulation of the Bcl-2 expression and reduction of AKT phosphorylation.

The chronic effect of palmitic acid on apoptosis of pancreatic islet beta-cells and the mechanism / 中国应用生理学杂志

<p><b>AIM</b>To investigate the chronic effect of palmitic acid (PA) on apoptosis of pancreatic islet beta-cells and the possible mechanism.</p><p><b>METHODS</b>Insulinoma cell line (MIN6 cells) were used in this study. After being incubated in PA (0.1 - 1.6 mml/L) for 24 and 48 hours, MTT method was used to evaluate the livability. After being incubated for 48 h, Hoechst-PI and Annexin-V-FTTC/PI FACS were used to estimate the apoptosis in each group, Western-blotting assay was used to estimate the protein level of p-Akt, Akt, Bax and Bcl-2.</p><p><b>RESULTS</b>Chronic PA dose-dependently (1) decreased the availability and increased the apoptosis of MIN6 cells; (2) decreased the phosphorylation of Akt and Bcl-2, but had no significant effects on Akt and Bax.</p><p><b>CONCLUSION</b>Chronic PA dose-dependently induced apoptosis of MIN6 cells, and this effect was possibly regulated by Akt/Bcl-2.</p>