| Research Background In the occurrence and development of liver fibrosis,pathogenic factors continuing to affect the liver and causing chronic liver injury have became an important reason for its progress.Common pathogenic factors include persistent viral infections,alcohol toxicity,non-alcoholic fatty liver,drug factors,and so on.The core link lies in the activation of hepatic stellate cells and the massive accumulation of extracellular matrix.Liver tissue produces a traumatic repair response to inflammatory damage,and this damage-repair process can eventually develop into diseases such as cirrhosis and liver cancer.Therefore,preventing the proliferation and activation of hepatic stellate cells and inhibiting the secretion of extracellular matrix by activated hepatic stellate cells has become an important way to reduce or even treat liver fibrosis.With the development of biochemistry and molecular biology,a large number of studies have confirmed that the activation of signaling pathways through drug inhibition is a hot spot in the treatment of liver fibrosis.For example,regulation of the TGF-β1 / Smads signaling pathway and its downstream cellular signaling proteins can effectively delay the progression of liver fibrosis disease.Previous studies have shown that LncRNA Malat1 is up-regulated in liver tissue of patients with liver fibrosis and isolated fibrosis model liver cell lines,and it plays an important role in the development of liver fibrosis.In addition,some literatures have confirmed that Mi RNA-195 can participate in the regulation of liver malignancies through Smad 7 protein.However,whether LncRNA Malat1,mi RNA-195 and Smad7 proteins act as signal axes in the development of liver fibrosis has not been reported.This topic will discuss this conjecture in depth.Objective: To explore the development mechanism of LncRNA Malat1-mi RNA-195-Smad7 signal axis in liver fibrosis,and provide new targets for the diagnosis and treatment of liver fibrosis.Methods: Liver tissues of patients with liver fibrosis(n=12)were collected,and the expression of LncRNA Malat1 in liver was detected by q RT-PCR.Twenty-four fullyaged C57 BL / 6J male mice aged 8-9 weeks were randomly divided into 4 groups of 6 mice,each group including normal control group,liver fibrosis group,liver fibrosis + lentiviral Malat1 gene knockout Except group,liver fibrosis + lentivirus Malat1 control group.The mice were sacrificed at the end of the 4th week,and the liver tissue morphology and size were observed.At the same time,q RT-PCR was used to detect the relative expression of LncRNA Malat1 and hsa-mi R-195-5p in mouse liver and serum.The expression of Malat1 in paraffin sections of mouse liver was detected by FISH.Western groups were used to detect each group’s expression of Smad7 protein and fibrosis-related protein α-SMA and type collagen Ⅰ.The human liver stellate cell LX-2 cell line was cultured in labotary.The cell lines were divided into 4 groups,including the normal control group,the LncRNA Malat1 silencing group,the normal control + TGF-beta1 stimulation model,and the LncRNA Malat1 + TGF beta1 stimulation control group.The liver fibrosis model was simulated by TGF injection to stimulate the proliferation of stellate cells,and the expression of LncRNA Malat1 was silenced by cell transfection.The expression of LncRNA Malat1 and Mi RNA-195-5p,the expression of Smad7 protein and the expression of fibrosis-related protein α-SMA and type I collagen in LX-2 cell lines of different groups were detected.Results: 1.The expression of LncRNA Malat1 was increased in liver tissues of patients with liver fibrosis,C57 mice modeled by CCL4,and fibrotic LX-2 cell models.2.For C57 BL / 6J mouse model,liver fibrosis model group can be seen with naked eyes.The liver fibrosis + lentivirus control group showed enlarged liver,rough liver surface and white nodules on part of liver surface.In the liver fibrosis + lentiviral gene knockout group,there were fewer white nodules on the surface of the liver,and the degree of roughness was lighter.The degree of fibrosis was between the model group and the normal group.3.In animal experiments,compared with the normal control group,the expressions of LncRNA Malat1 and hsa-mi R-195-5p in liver fibrosis group and liver fibrosis + lentivirus control group increased,Smad7 expression decreased,α-SMA and I Increased collagen expression.Compared with the normal control group,the expression of LncRNA Malat1 and hsa-mi R-195-5p in the liver fibrosis + lentiviral gene knockout group decreased,the expression of Smad7 protein increased,the expression of α-SMA and Col1 decreased,and liver fibrosis in mice Relieved.4.In cell experiments,silencing LncRNA Malat1 can down-regulate the expression of mi RNA-195,up-regulate the expression of Smad7 protein,and reduce the expression of fibrosis-related proteins α-SMA and Col1,to a certain extent,alleviate the degree of fibrosis of hepatic stellate cells.Conclusion: LncRNA Malat1 binds to its downstream regulatory factor mi R-195 and regulates Smad7 to participate in fibrosis.Silencing Malat1 can reduce the expression of α-SMA and type I collagen and relieve liver fibrosis. |
