The MiRNA Expression Profile In Acute Myocardial Infarct Using Sheep Model With Left Ventricular Assist Device Unloading

Background and AimsCardiomyocytes due to lack of regeneration capacity,encountered ischemia and hypoxia and other causes will lead to myocardial cell damage,resulting in myocardial cell loss,fibrous tissue hyperplasia,causing ventricular remodeling,and gradually progress into heart failure.The left ventricular cycle auxiliaries(LVAD)have been shown to be an effective means of treating heart failure,and the use of LVAD for mechanical circulation support can have a beneficial effect on the way of depletion of the left ventricle.However,the application of LVAD in the treatment of acute myocardial infarction needs further study,LVAD on the late AMI prognosis and its mechanism to be further elucidated.MiRNA(miRNA)is an endogenous non-coding single-stranded small molecule RNA consisting of 21-23 bases,which regulates gene expression at post-transcriptional levels.MiRNA is involved in a variety of pathophysiological processes.At present,the function and mechanism of miRNAs in myocardial ischemia are still at the initial stage,especially in the early stage of myocardial ischemia.Also did not take the LVAD intervention in the early AMI,the analysis of the internal miRNA of cardiomyocytes,and its related signal pathway.This paper attempts to establish miRNA expression profile on sheep acute myocardial infarction model,and provide theoretical basis for LVAD treatment of acute myocardial infarction.Methods1?The adult small-tail Han sheep was treated with ligation of the coronary artery and the heart was anchored into the FW-2 axial-flow pump respectively for the control group and unloading load group2?After models were established,the ECG was detected,and we placed into the Swan-gaze floating catheter for testing.3?72 hours later,respectively,the control group and unloading group of myocardial tissue were divided into normal area,infarct zone area and infarct area and then we did tissue staining.4?TUNEL method was used to detect the apoptosis of myocardial cells.5?High-throughput sequencing technology to establish miRNA expression profiles.6?We compared miRNAs that were differentially expressed in the myocardium of the control and unloading groups7?PCR was used to verify the results of sequencing.8?After the validation of differentially expressed miRNAs,we test their function and the signal path analysis.Results1?There were 7 animals in the control group,3 of which were successfully modeled.LVAD group of animals,a total of five experiments,of which three were successful.2?The results of HE staining showed that compared with the control group,the damage of myocardial cells in the unloading group was decreased and the inflammation Cell infiltration was significantly reduced.Masson staining showed that the area of collagen was reduced and the number of cardiomyocytes remained.Sirius red staining results showed significant reduction in collagen removal in the unloading group.Contrast infarct area,after unloading load there is mainly type ? collagen,while the control group has mainly type ? collagen.3?TUNEL results showed that the unloading load group and the control group,myocard TUNEL results showed that the myocardial apoptosis was significantly decreased after unloading of myocardial infarction.The percentage of apoptosis was significantly decreased(P<0.001).4?Compared with the control group,the differentially expressed miRNA was oar-miR-19b(up-regulated)in the infarcted region.There were three differentially expressed miRNAs in the infarction border zone,and oar-miR411b-5p and Oar-miR-487a-5p were down-regulated,oar-miR-26a was up-regulated.5?The results of PCR showed that oar-miR-19b(P<0.05)and oar-miR-26a(P<0.01)were significantly different from those in the control group,and the results were consistent with chip results.6?GO and KEGG analysis showed that the functions and signaling pathways involved in oar-miR-19b and oar-miR-26a were closely related to cardiovascular disease.ConclusionIn this study,LVAD effectively reduced the cell death degree of cardiomyocyte in AMI after unloading three days.The established and validated miRNA expression profiles of AMI and LVAD intervention in this study,suggests that the expression profile could be used to explore the unknown miRNA,including their function in AMI and LVAD unloading,and investigate the regulatory mechanisms involved in AMI.