circTRRAP敲低通过调节miR-323-3p/SMAD2轴在急性心肌梗死中的研究

Study of circTRRAP knockdown in acute myocardial infarction by regulating miR-323-3p/SMAD2 axis

摘要

目的：探讨circTRRAP在急性心肌梗死（acute myocardial infarction,AMI）中的特定作用。方法：心肌梗死模型由缺氧24 h诱导。使用双萤光素酶报告基因测定来测试circTRRAP、SMAD2和miR-323-3p之间的相互作用。通过转染sicircTRRAP，敲低与过表达microRNA-323-3p、过表达SMAD2后检测促炎细胞因子[白细胞介素-6(interkeukin-6,IL-6)与肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)]和氧化应激标志物[丙二醛（malondialdehyde,MDA）与超氧化物歧化酶（superoxide dismutase,SOD）]以及细胞凋亡因子[Bcl-2相关X蛋白（Bcl-2-associated X protein,Bax）、B细胞淋巴瘤-2(B-cell lymphoma-2,Bcl-2),Cleaved Caspase-3]表达来研究其在心肌梗死细胞中作用。结果：在心肌梗死损伤模型中，circTRRAP与SMAD2水平明显升高超过50%，而miR-323-3p表达明显降低。circTRRAP的下调通过促进miR-323-3p表达导致SMAD2的表达减少。SMAD2与miR-323-3p呈负相关，但与circTRRAP表达呈正相关。circTRRAP与SMAD2的下调或miR-323-3p的上调可提高细胞活力与减少心肌细胞凋亡率。结论：circTRRAP的下调导致炎症的抑制，并通过miR-323-3p/SMAD2轴减轻AMI。

Abstract

Objective To investigate the specific role of circTRRAP in acute myocardial infarction（AMI）. Methods The method of hypoxia for 24 hours was used to induce the model of myocardial infarction，and the dual-luciferase reporter assay was used to investigate the interaction between circTRRAP，SMAD2，and miR-323-3p. After knockdown and overexpression of miR-323-3p and overexpression of SMAD2 through transfection with si-circTRRAP，the expression levels of proinflammatory cytokines ［interkeukin-6（IL-6） and tumor necrosis factor-α（TNF-α）］，oxidative stress markers ［malondialdehyde（MDA） and superoxide dismutase（SOD）］，and apoptotic factors［Bcl-2-associated X protein（Bax），B-cell lymphoma-2（Bcl-2），and cleaved caspase-3］were measured to investigate the role of circTRRAP，SMAD2，and miR-323-3p in myocardial infarction. Results In the model of myocardial infarction injury，the levels of circTRRAP and SMAD2 were significantly increased by more than 50%，whereas there was a significant reduction in the expression of miR-323-3p. The downregulation of circTRRAP led to a reduction in SMAD2 expression by promoting miR-323-3p expression. SMAD2 was negatively correlated with miR-323-3p，but it was positively correlated with the expression of circTRRAP. The downregulation of circTRRAP or SMAD2 or the upregulation of miR-323-3p could increase cell viability and reduce the apoptosis rate of cardiomyocytes. Conclusion Downregulation of circTRRAP can inhibit inflammation and alleviate AMI via the miR-323-3p/SMAD2 axis.

关键词

环状RNA / 基因调控 / 细胞凋亡 / 心肌梗死

Key words

circular RNA / gene regulation / cell apoptosis / myocardial infarction