Preliminary Exploration Of The Effects And Mechanisms Of Mirnas On CCL2Pathway In The Secondary Brain Injury After Intracerebral Hemorrhage In Rat

BackgroundIntracerebral hemorrhage(ICH) is a common and fatal subtype of stroke.The key role affecting the prognosis of ICH is secondary brain injury. Extensive research has demonstrated that ICH triggers complex cellular biochemical events that eventually lead to secondary brain injury. However, the delicate mechanisms of ICH induced secondary brain injury are not completely understood. MicroRNAs have been recently discovered as a novel family of non-protein coding short RNA molecules that negatively modulte protein expression in virous organisms.It is now evident that miRNAs plays acritical role in a ariety of normal biological process, including cell differentiation, apoptosis, development and metabolism. In addition, miRNAs have also been implicated in etiology of variety of human disease, including cancer, cardiovascular diseases and stroke. Our previous study have demonstrated that CCL2/CCR2pathway play an important role in the secondary brain injury after ICH. Based on these data, this study is to investigate the expression of MCP-1related miRNAs in a rat ICH model and elucidate the role of miRNAs in the pathogenesis of the ICH induced secondary brain injury.MethodsIn this study, we predict possible targeting MCP-1mRNA by bioinformatics techniques,and a preliminary screening test was carried out in a rat ICH model.A total of81rats were randomly divided into3groups:sham group(acupuncture basal ganglia model),control group(saline basal ganglia injection model)and treat group(autologous blood basal ganglia injection model).Rats were decapitated and collected brain sample2hours,6hours,12hours after respectively. Total RNA was isolated from rat brain samples,and the expression of MCP-1mRNA and miRNAs were measured by real-time PCR.ResultsThe expression of MCP-1mRNA increased significantly after ICH, which was29.44±0.18at3h,73.84±1.16at6h and25.86±15.31at12h, respectively. At the same time, the expression of rno-miR-3592was20.58±0.64at3h,16.06±0.98at6h,and15.24±1.29at12h, respectively. The expression of rno-miR-434*was20.58±0.64at3h,16.08±0.98at6h, and15.24±1.29at12h, respectively. Correlation analysis revealed that rno-miR-3592and rno-miR-434*are strongly correlated with the expression of MCP-1mRNA.ConclusionOur study describes the dynamic changes of MCP-1mRNA and the related miRNA in the brain tissue around hematoma at early stage after ICH.rno-miR-3592,rno-miR-434*showed progressive decrease when MCP-1mRNA expression levels showed a progressive upward trend. Thus, we speculate that rno-miR-3592and rno-miR-434*may modulate the expression of MCP-1expression in ICH. However, futher studies are needed to elucidate the effect and mechanisms of rno-miR-3592and rno-miR-434*on MCP-1signaling pathway in ICH induced secondary brain injury following ICH.