AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration ...AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration of CCl4 for 8 wk.Pathological changes in the liver of rats were examined by hematoxylin-eosin staining.Collagen fibers were detected by Sirius red staining.Hepatocyte apoptosis was determined by TUNEL assay and the expression levels of cleaved caspase-3,Bax,α-SMA,connective tissue growth factor(CTGF),matrix metalloproteinase(MMP) 2 and MMP9 proteins were evaluated by western blot analysis,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were estimated by real-time PCR.RESULTS:Treatment with GA significantly improved the pathological changes in the liver and markedly decreased the positive area of Sirius red compared with rats in the CCl4-treated group.TUNEL assay showed that GA significantly reduced the number of TUNEL-positive cells compared with the CCl4-treated group.The expression levels of cleaved caspase-3,Bax,α-SMA,CTGF,MMP2 and MMP9 proteins,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were also significantly reduced by GA compared with the CCl4-treated group(P < 0.05).CONCLUSION:GA treatment can ameliorate CCl4-induced liver fibrosis by inhibiting hepatocyte apoptosis and hepatic stellate cell activation.展开更多
Background The function of peroxisome proliferator-activated receptor γ （PPARγ） in hepatic fibrogenesis remains largely unknown. Curcumin is a natural substance extracted form Curcuma Longa Linn and has a variety ...Background The function of peroxisome proliferator-activated receptor γ （PPARγ） in hepatic fibrogenesis remains largely unknown. Curcumin is a natural substance extracted form Curcuma Longa Linn and has a variety of pharmacological effects. In this study, the effects of curcumin on the proliferation, activation and apoptosis of rat hepatic stellate cells （HSCs） through PPARγ signaling were investigated. Methods HSCs were isolated from the normal Sprague Dawley rats through in situ peffusion of the liver with Pronase E and density-gradient centrifugation with Nycodenz. Cells were treated with curcumin, troglitazone, salvianolic acid B or GW9662. The effect on HSCs proliferation was determined by MTT colorimetry. Total RNA was extracted by TRizol reagent and gene levels were determined by semi-quantitative RT-PCR. Total cellular and nuclear protein were isolated and separated by 10% sodium dodecy Isulfate polyacrylamide gel electrophoresis. Protein levels were determined by Western blot. Cell apoptosis was detected by Hoechst 33258 staining. PPARγ subcellular distribution was detected by immunofluorescent staining. The activities of MMP-2 and 9 were measured by Gelatin zymograph assay. Results Curcumin suppressed HSCs proliferation in a dose-dependent manner. As HSCs underwent gradual activation with culture prolongation the PPARγ nuclear expression level decreased. Curcumin up-regulated PPARγ expression and significantly inhibited the production of a-SMA and collagen Ⅰ. PPARγ is expressed in the cytoplasm and nucleus and is evenly distributed in HSCs, but accumulated in the nucleus of HSCs and disappeared from cytoplasm after curcumin treatment. Hoechst 33258 staining showed that curcumin induced the apoptosis of culture-activated HSCs and significantly increased pro-apoptotic Bax expression and reduced anti-apoptotic Bcl-2 expression. Cyclin D1 gene, activated NFKB p65 protein and TGFβR-Ⅰ protein expression were down-regulated significantly by curcumin. The activities of MMP-2 and MMP-9 were e展开更多
基金Medical and Health Science and Technology Planning Project of Zhejiang Province in 2012,China,Grant NO.2012RCB007
文摘AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration of CCl4 for 8 wk.Pathological changes in the liver of rats were examined by hematoxylin-eosin staining.Collagen fibers were detected by Sirius red staining.Hepatocyte apoptosis was determined by TUNEL assay and the expression levels of cleaved caspase-3,Bax,α-SMA,connective tissue growth factor(CTGF),matrix metalloproteinase(MMP) 2 and MMP9 proteins were evaluated by western blot analysis,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were estimated by real-time PCR.RESULTS:Treatment with GA significantly improved the pathological changes in the liver and markedly decreased the positive area of Sirius red compared with rats in the CCl4-treated group.TUNEL assay showed that GA significantly reduced the number of TUNEL-positive cells compared with the CCl4-treated group.The expression levels of cleaved caspase-3,Bax,α-SMA,CTGF,MMP2 and MMP9 proteins,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were also significantly reduced by GA compared with the CCl4-treated group(P < 0.05).CONCLUSION:GA treatment can ameliorate CCl4-induced liver fibrosis by inhibiting hepatocyte apoptosis and hepatic stellate cell activation.
基金This project was supported by the grants from the National Natural Science Foundation of China(No.30300458)Shanghai Leading Academic Discipline Project(No.Y0302)
文摘Background The function of peroxisome proliferator-activated receptor γ （PPARγ） in hepatic fibrogenesis remains largely unknown. Curcumin is a natural substance extracted form Curcuma Longa Linn and has a variety of pharmacological effects. In this study, the effects of curcumin on the proliferation, activation and apoptosis of rat hepatic stellate cells （HSCs） through PPARγ signaling were investigated. Methods HSCs were isolated from the normal Sprague Dawley rats through in situ peffusion of the liver with Pronase E and density-gradient centrifugation with Nycodenz. Cells were treated with curcumin, troglitazone, salvianolic acid B or GW9662. The effect on HSCs proliferation was determined by MTT colorimetry. Total RNA was extracted by TRizol reagent and gene levels were determined by semi-quantitative RT-PCR. Total cellular and nuclear protein were isolated and separated by 10% sodium dodecy Isulfate polyacrylamide gel electrophoresis. Protein levels were determined by Western blot. Cell apoptosis was detected by Hoechst 33258 staining. PPARγ subcellular distribution was detected by immunofluorescent staining. The activities of MMP-2 and 9 were measured by Gelatin zymograph assay. Results Curcumin suppressed HSCs proliferation in a dose-dependent manner. As HSCs underwent gradual activation with culture prolongation the PPARγ nuclear expression level decreased. Curcumin up-regulated PPARγ expression and significantly inhibited the production of a-SMA and collagen Ⅰ. PPARγ is expressed in the cytoplasm and nucleus and is evenly distributed in HSCs, but accumulated in the nucleus of HSCs and disappeared from cytoplasm after curcumin treatment. Hoechst 33258 staining showed that curcumin induced the apoptosis of culture-activated HSCs and significantly increased pro-apoptotic Bax expression and reduced anti-apoptotic Bcl-2 expression. Cyclin D1 gene, activated NFKB p65 protein and TGFβR-Ⅰ protein expression were down-regulated significantly by curcumin. The activities of MMP-2 and MMP-9 were e
