Study On The Protective Effect Of Knocking Down RAGE On Myocardial Ischemia Reperfusion Injury

Background:Acute myocardial infarction?AMI?is the leading cause of morbidity and mortality worldwide.Timely reperfusion is the first principal treatment for ischemic myocardium,while the process of reperfusion can itself induce cardiomyocyte death,known as myocardial ischemia reperfusion injury?MIRI?.The mechanism of ischemia-reperfusion injury is unclear and according to the current studies,it has been proved that the reperfusion can induce a chain of inflammatory responses result in myocardial injury.RAGE,the receptor for advanced glycation end products,is a transmembrane receptor of the immunoglobulin super family and its name comes from its ability to bind advanced glycation endproducts?AGE?.Research Indicates that the interaction between RAGE and its ligands is thought to result in various RAGE-dependent pathway activation,it causes reactive oxygen species?ROS?to generate rapidly and increase the expression of inflammatory cytokines,extended inflammatory response,causing a cascade of proinflammatory,injured endothelial cell and inducing apoptosis of cardiac cells,damaged cardiac tissue,damage to the cardiovascular system.Reports have shown that knock down the RAGE gene showed a protective effect in the treatment of myocardial infarction..Method:PEI-SeSe was successfully synthesized via the Michael addition between selenium-containing diacrylate and low molecular weight polyethyleneimine?PEI?.Transcriptional activator protein?TAT?further functioned of the polymer to get the gene transfer vector TAT-PEI-Se,and preparation of TAT-PEI-Se/siRNA complexes.The vitro experiments were taken in H9C2 cardiomyocytes and the vivo taken in the rat model of myocardial ischemia-reperfusion injury.Results:Our study shows TAT-PEI-Se/siRNA polyplexes could rapidly release siRNA after H₂O₂?0.1 mM?treatment and it was stable under serum.Intracellular kinetics investigation showed that the total cellular uptake of TAT-PEI-Se/siRNA polyplexes is extremely high and exhibited a high gene transfection efficiency and low cytotoxicity in vitro.In vivo transfection showed that TAT-PEI-Se/siRAGE polyplexes inhibited the expression RAGE and the expression of tumor necrosis factor??TNF-??and interleukin-6?IL-6?also were reduced notably.From the 2,3,5-Triphenyltetrazolium chloride?TTC?staining and Masson trichrome staining,we can observed that the cardiac infarct size was smaller and the cardiac fibrosis was decreased.Echocardiography test evaluated that the Cardiac function was improved.Conclusion:In summary,we have created the vector for siRNA delivery system,TAT-PEI-Se,which was able to deliver the siRAGE to cardiocyte efficiently.Thus,TAT-PEI-Se/siRAGE delivery system has a potential for the clinical applications to treat the myocardial disease.