The CircRNA Circ₀01131 Inhibits Cardiomyocyte Hypertrophy Via Targeting Mir-25-3p

Cardiac hypertrophy is usually characterized by an increase in myocardial cell size and thickening of the ventricular wall.Initially,this growth is an adaptive response to maintaining cardiac function;however,under constant stress,over time,chronic stress or disease will lead to ventricular dilatation,accompanied by decreased function and eventually progression to heart failure.Circular RNA?circRNA?is a closed circular non-coding RNA,which is an important epigenetic regulation and participates in the development of various cardiovascular diseases.The model of cardiac hypertrophy induced by abdominal aortic coarctation was constructed by our group,and the hypertrophic model was sequenced by chip expression to find out the circRNA with different expression.We chose the circRNA circ 001131,which is up-regulated in a hypertrophic model.And the function of circ 001131 in cardiac hypertrophy has not been reported.This paper studies the regulation and mechanism of circRNA circ 001131 on cardiac hypertrophy.Objective:To elucidate the expression of circRNA circ 001131 in hypertrophic myocardium and its regulation mechanism on cardiac hypertrophy..Methods:1.An animal model of myocardial hypertrophy induced by abdominal aortic coarctation?AAC?was established;2.Primary isolation and culture of 1 to 3 days of neonatal rat ventricular cardiomyocytes cardiomyocytes?NRVCs?,with 100 ?M Phenylephrine?PE?induced cardiomyocyte hypertrophy model;3.FITC-Phalloidin staining to detect myocardial cell surface area in milk rats;4.Construction of circ 001131 recombinant adenovirus?rAd-circ₀01131?and NRVCs were infected with Ad-circ 001131;5.Detecting the nuclear distribution of circ₀01131 in NRVCs;6.Using RNA pull-down,RAP and dual luciferase reporter assays for circ_PTEN and microRNA?miRNA?miR-25-3p binding;7.RT-qPCR,Western Blot assay to detect the expression of hypertrophic related genes.Results:1.Circ₀01131 and PTEN were up-regulated in Abdominal aortic coarctation?AAC?-induced rat cardiac hypertrophy;2.With the treatment of 100?M PE for 24 h,cardiomyocyte hypertrophy cell model was successfully induced in NRVCs,and circ 001131 and its host gene PTEN were up-regulated;3.Successful construction of rAd-circ 001131 and the expression of cardiac hypertrophy-related genes were inhibited after over-expression of circ 001131 in NRVCs;4.circ₀01131 was mainly localized in the cytoplasm and interacted with endogenous miR-25-3p;5.NRVCs with overexpression of miR-25-3p can up-regulate the expression of hypertrophic related genes;6.Overexpression of circ₀01131 and miR-25-3p up-regulated and down-regulated the expression of DKK3 respectively,and si-DKK3 up-regulated the expression of hypertrophic-related genesConclusion:1.Circ 001131 and PTEN were up-regulated in AAC-induced animal hypertrophy model and PE-induced NRVCs cell hypertrophy model;2.Overexpression of circ 001131 inhibited cardiomyocyte hypertrophy phenotype;3.Circ₀01131 targeted miR-25-3p to inhibit cardiomyocyte hypertrophy.