The Role Of MiR-383 On Oxidative Damage Of Rat Liver By Acute Cold Exposure

Cold stress is a common stress factor in the winter of northern China.Animals survive in low temperature environment for a long time,liver tissue damage is more serious,mainly manifested in abnormalities of morphology and function,but the specific formation mechanism is still unclear.mi RNAs are a class of small non-coding RNAs that are involved in various biological processes.In the preliminary work of the laboratory,found that mi R-383 was down-regulated in the liver tissue of acute cold stress rats,and mi R-383 is an important regulator in biological processes such as cell proliferation and apoptosis by searching the literature,but there are very few studies involving the mediation of cold stress in rat liver tissues.Therefore,the purpose of this study was to determine the effect of mi R-383 on the livers of cold stress rats by simulating the cold stress state of rat liver tissues in vitro,using H2O2 to induce rat hepatocyte oxidative stress.Firstly,the oxidative stress markers,apoptosis indexes and mi R-383 expression in rat liver were examined by Western Blot,kit and q RT-PCR,respectively.Then the mi R-383 function was performed by bioinformatics methods.Finally,the function of mi R-383 was studied in vitro and the target of mi R-383 was testified.The results showed that MDA content,Caspase 3 and Cyto C protein levels increased significantly(p<0.05);GPx activity and SOD1 protein levels decreased significantly(p<0.05)and mi R-383 expression was significantly down-regulated(p<0.01)in rat liver tissues after cold stress.The apoptosis rate,ROS levels and mi R-383 expression increased significantly(p<0.01)in rat hepatocytes after treated with H2O2(50,100,150 ?M),the optimal conditions for up-regulation of mi R-383 were determined by transfection of mimics 100 pmol for 24 h;the optimal conditions for down-regulation were transfection of 60 pmol for 24 h.Under the condition of H2O2 stimulation,the apoptosis rate,Caspase 3 and Cyto C protein levels were significantly decreased as well as the level of mitochondrial membrane potential significantly increased in hepatocytes after down-regulation of mi R-383 expression(p<0.05),but ROS levels and Nrf2 protein expression had no significant change(p>0.05).In rat liver tissue and hepatocytes,the expression of mi R-383 and Bcl2 were negatively correlated,and the dual luciferase reporter gene assay also confirmed that mi R-383 can target the regulation of Bcl2 expression.Conclusion: the down-regulation of mi R-383 expression in oxidative stress rat hepatocytes may inhibit rat hepatocytes apoptosis by targeting Bcl2 translation;the down-regulation of mi R-383 expression may protect the rat liver tissue by increasing the translation of the anti-apoptotic protein Bcl2 in rat liver tissue under cold exposure.