| Liver fibrosis（LF）is the result of chronic liver injury from multiple causes,including continuous viral infection,alcoholic toxicity and non-alcoholic steatohepatitis.LF is characterized by superabundant deposition of extracellular matrix（ECM）,leading to a wound-healing response to the inflammation injury and eventually develop into liver cirrhosis and liver carcinoma.During the procession of LF,activated hepatic stellate cells（HSCs）are the primary source of ECM.Therefore,the proliferation and activation of HSC is a crucial step in the development of LF.Thereby,inhibiting proliferation and activation of HSCs has become the most important treatment strategy for liver fibrosis.With the development of molecular biology,inhibiting the activation of signaling pathway by drug has become a hot spot in the treatment of liver fibrosis and some achievements have been made.Currently,many studies have found that the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1 play a regulatory role in various fibrotic diseases.According to the study,Wnt/β-catenin signaling pathway,c-Myc and cyclin D1 were activated during the occurrence and development of liver fibrosis.In recent years,there have been a number of studies illustrated that octreotide（OCT）,an analogue of somatostatin,can attenuate liver fibrosis.However,there are few studies on whether OCT can alleviate liver fibrosis by inhibiting the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1.Therefore,it is worth to discuss for further.In our study,the level of Wnt/β-catenin signaling pathway,c-Myc and cyclin D1in the procession of liver fibrosis was investigated,and the effect of OCT on hepatic fibrosis and the molecular mechanism were further studies.The main study contents are as follows:（1）Effects of OCT on liver fibrosis in ratsFirstly,we established the model group rats by hypodermically injecting carbon tetrachloride（CCl4）and the OCT treatment group by hypodermically injecting CCl4and OCT.Then,serum samples and liver tissue samples were collected from the normal group,the model group and the OCT group,respectively.Hematoxylin and Eosin（H&E）staining and Masson staining in liver tissue verified liver fibrosis model was successfully established.The activites of TBIL,AST,ALT and ALB from each serum sample were measured by biochemical detection kit.Meanwhile,the level ofα-SMA and Collagen I were measured by western blot,qRT-PCR and immunohistochemistry.The results showed that OCT can attenuate liver fibrosis in rats.（2）Effects of OCT on the expression of the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1in liver fibrosis in ratsIn rats liver fibrosis tissues,the expression of Wnt1 andβ-catenin were messured by immunohistochemistry,western blot and qRT-PCR,and the expression of c-Myc and cyclin D1 were measured by western blot.The results revealed that the Wnt1、β-catenin、c-Myc and cyclin D1 were up-regulated in the liver tissues of rats in the model group,and were down-regulated in the OCT group.（3）Effects of OCT on the proliferation of LX-2 cellsThree different concentrations of OCT(10-8,10-7,10-66 mol/L)were used to treat LX-2 cells,and the cell viability was messured by MTT assay.The results indicated that OCT has no lethal effect on the LX-2 cells.Meanwhile,activation of LX-2 cells was treated with OCT,and the absorbance value was detected by MTT assay.The results showed that OCT had a concentration-dependent inhibitory effect on cell proliferation.（4）Effects of OCT on the activation of LX-2 cellsTGF-β1-treated LX-2 cells were treated with three different concentrations of OCT（10-88 mol/L,10-77 mol/L,10-66 mol/L）,and the expression ofα-SMA and Collagen I were detected by western blot and qRT-PCR.The results showed that OCT had a concentration-dependent inhibitory effect on cell activation.（5）Effects of OCT on the expression of the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1in activated LX-2 cellsThree different concentrations of OCT(10-8,10-7,10-66 mol/L)were used to treat LX-2 cells.The expression of Wnt1 andβ-catenin were messured by western blot and qRT-PCR,and the level of c-Myc and cyclin D1 were measured by western blot.The results revealed that the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1 were up-regulated in the activated LX-2 cells,and were down-regulated in the OCT treatment.In conclusion,these results suggested that OCT can reduce the proliferation and activation of HSCs and liver fibrosis by inhibiting the Wnt/β-catenin signaling pathway,c-Myc and cyclin D1. |
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