MiR-24 Reduces Serum Lipid Levels And Inhibits Brain Tissue Cells Apoptosis Of Rats With Cerebral Infarction

Background:Cerebral infarction is a cerebrovascular disease caused by cerebral blood supply disorders and one of the leading causes of death and disability worldwide.MicroRNAs are endogenously expressed non-coding short-chain single-stranded RNAs that play a role in the regulation of post-transcriptional gene expression levels by degradation or inhibition of target mRNA translation.Recent studies have revealed the important role of miRNAs in ischemic diseases.Objective:The aim of the study was to evaluate the effect of miR-24 on cerebral infarction in rats by constructing a rat middle cerebral artery occlusion model(MCAO).Materials and Methods:Fifty male Sprague-Dawley rats were divided into normal,sham-operated,MCAO model group,miR-24 agomir and miR-24 antagomir groups.The MCAO rat model was constructed and stereotactically injected miR-24 agomir and antagomir in the brain of the model.The serum total cholesterol,serum high-density lipoprotein cholesterol and triglyceride levels in rat blood were determined by automatic biochemical analyzer.Subsequently,the infarct size of each group was detected by TTC staining.Real-time polymerase chain reaction was used to detect the expression level of miR-24.The expression level of Caspase 3 protein was detected by immunohistochemistry combined with western blot.Finally,the effect of miR-24 on apoptosis of rat brain infarction cells was detected by Tunel staining.Results:A well-modeled rat was screened by Zea Longa score,and a total of 9 rat models were enrolled in each group.Compared with the normal and sham-operated groups,miR-24 expression levels were significantly decreased in the MCAO model group,miR-24 agomir,and miR-24 antagomir groups(P<0.05),percentage of cerebral infarct size,apoptotic cells and relative caspase-3 protein expression was significantly increased(P<0.05).Serum total cholesterol,serum high-density lipoprotein cholesterol,and triglyceride levels were significantly higher in the MCAO model and miR-24 antagomir group than that in the normal and sham-operated groups(P<0.05).Compared with the MCAO model group,the expression of miR-24 in the miR-24 agomir group was significantly increased(P<0.05)and serum total cholesterol,serum high-density lipoprotein cholesterol and triglyceride content,percentage of cerebral infarct size,The number of apoptotic cells and the expression of caspase-3 showed a downward trend(P<0.05),which was in contrast with the trend in the miR-24 antagomir group.Conclusion:Overexpression of miR-24 can significantly reduce the levels of total cholesterol,serum high-density lipoprotein cholesterol and triglyceride in rats with cerebral infarction,and inhibit the apoptosis of brain tissue cells.Our data suggest that our use of miR-24 agonists may be an attractive therapeutic strategy for cerebral infarction.