Mechanism Study Of Circular RNA CircRNA＿001131 Inhibiting Cardiomyocyte Hypertrophy Through MiR-25-3p/BTG2/SOD2 Axis

Cardiac hypertrophy usually refers to changes characterized by enlargement of cardiomyocytes and thickening of the ventricular wall that occur when the hemodynamics is too large or the myocardium is overloaded.Initially,this change was an adaptation made by the body to maintain heart function.However,if the stress persists,these changes gradually evolve from adaptive to compensatory,eventually leading to heart failure in severe cases.Circular RNAs(circRNAs)are a class of closed circular non-coding RNAs that can participate in the occurrence and development of various cardiovascular diseases.This paper intends to study the regulatory effect and molecular mechanism of circRNA＿001131 derived from the host gene-phosphatase and tensin homolog(PTEN)on cardiac hypertrophy.Objective:This article aims to investigate the regulatory effect and molecular mechanism of circular RNA circRNA＿001131 on cardiac hypertrophy.Methods:1.Real-time quantitative PCR(RT-qPCR)was used to detect the expression of circRNA＿001131 and host gene Pten in isoproterenol(ISO)-induced hypertrophic rat myocardium and ISO-treated milk rat hypertrophic cardiomyocytes(NRVCs).2.Rnase R experiment was used to verify the RNA stability of circRNA＿001131.3.Recombinant adenovirus rAd-circRNA＿001131 was used to infect C57BL/6 neonatal mouse cardiomyocytes(NMVCs),and RT-qPCR and Western blot were used to detect the overexpression of circRNA＿001131 pair.The effects of cardiac hypertrophy-related β-myosin heavy chain(β-MHC),skeletal muscle α-actin(ACTA1),and atrial natriuretic(ANP)expression.4.Phalloidin staining to detect the effect of circRNA＿001131 on the myocardial cell surface area Impact.5.Transfect miR-25-3p mimic into NMVCs to detect the regulatory effect on cardiac hypertrophy phenotype.6.Verify the binding between circRNA＿001131 and miR-25-3p by dual luciferase reporter gene assay,RNA pull-down assay and RIP,and functionally clarified the inhibitory effect of miR-25-3p-mediated circRNA＿001131 on cardiomyocyte hypertrophy.7.Identification of the downstream target gene BTG2 of miR-25-3p,BTG2-mediated miR-25-3p on the hypertrophic phenotype of NMVCs.8.Combined with mRNA expression profiling,RT-qPCR and actinomycin D experiments to study the up-regulation effect of BTG2 on Sod2.9.Verify that BTG2 and SOD2 are involved in mediating the inhibitory effect of circRNA＿001131 on the hypertrophic phenotype of cardiomyocytes.10.Verify that circRNA 001131 inactivates NF-κB signaling to suppress the hypertrophic phenotype of NMVCs.Results:1.CircRNA＿001131 and Pten were up-regulated in ISO-induced hypertrophic rat myocardium and ISO-treated NRVCs.2.Actinomycin D experiment and Rnase R experiment confirmed that circRNA＿001131 has characteristic RNA stability 3.Overexpression of circRNA＿001131 in NMVCs can inhibit the downregulation of β-MHC,ACTA1 and ANP expression related to cardiac hypertrophy.4.Phalloidin staining experiments showed that circRNA 001131 can inhibit the increase of the surface area of NMVCs.5.MiR-25-3p mimic could enhance the expression of cardiac hypertrophy-related genes in NMVCs.6.In NMVCs,miR-25 was confirmed3p binds to circRNA＿001131,and miR-25-3p mediates the inhibitory effect of circRNA＿001131 on cardiomyocyte hypertrophy.7.It is clear that the downstream target gene BTG2 of miR-25-3p can inhibit the expression of cardiac hypertrophyrelated genes,and BTG2 is involved in mediating circRNA＿001131 to inhibit the hypertrophy of NMVCs.8.RT-qPCR,Western blot and actinomycin D experiments confirmed that BTG2 up-regulated the expression of SOD2 by enhancing the stability of SOD2 mRNA.9.Overexpression of SOD2 can inhibit the expression of cardiomyocyte hypertrophy-related genes,and BTG2-SOD2 is involved in mediating the inhibitory effect of circRNA＿001131 on cardiomyocyte hypertrophy.10.The circRNA＿001131/miR-25-3p/BTG2/SOD2 axis exerts an inhibitory effect on the hypertrophic phenotype of cardiomyocytes by inhibiting NF-κB signaling.Conclusion:1.The expression of circRNA＿001131 is up-regulated in ISOinduced hypertrophic rat myocardium and hypertrophic NRVCs.2.circRNA＿001131 upregulates the expression of the target gene BTG2 by specifically adsorbing miR-253p,thereby increasing the stability of SOD2 mRNA and protein expression,and further inhibiting the activation of NF-κB signaling and the expression of cardiac hypertrophyrelated genes.