microRNA-29a对肥大心肌细胞细胞周期的影响研究

Study of miR-29a in Myocardial Hypertrophy Cell Cycle

摘要: 心血管疾病严重威胁人类健康，其中心肌肥大和心肌纤维化是心血管疾病发展的主要表现。microRNA-29在心肌肥大和纤维化过程中都发生异常表达，并且参与纤维化、肿瘤增殖等过程。本研究通过建立肥大心肌细胞体外模型，研究miR-29a在心肌肥大过程中的变化水平及肥大心肌细胞细胞周期相关蛋白的表达模式变化。将常规培养H9C2心肌细胞系使用1 × 10⁻⁵、1 × 10⁻⁶和1 × 1⁻⁷ mol/L浓度的AngII诱导48 h后，检测细胞面积、细胞总蛋白含量，确定肥大心肌细胞诱导结果；再利用qPCR方法检测不同组的miR-29a、Cyclin A2、Bcl-2、Plk-1表达水平。结果显示使用浓度为1 × 10⁻⁵、1 × 10⁻⁶ mol/L的AngII对H9C2诱导48 h后，细胞面积明显增大，细胞的总蛋白含量也增加，并且miR-29a表达水平显著升高；细胞周期相关的CyclinA2、Bcl-2和Plk-1在高浓度(1 × 10⁻⁵ mol/L) AngII诱导后表达水平上升，低浓度(1 × 10⁻⁷ mol/L) AngII诱导后表达水平下降。在肥大心肌模型建立过程中，miR-29a可能能够对细胞周期相关基因产生抑制。

Abstract: Cardiovascular disease is a serious threat to human health, among which myocardial hypertrophy and myocardial fibrosis are the main manifestations of the development of cardiovascular disease. microRNA-29 was abnormally expressed in the process of myocardial hypertrophy and fibrosis, and was involved in fibrosis, tumor proliferation and other processes. In this study, an in vitro model of hypertrophic cardiomyocytes was established to study the changes of miR-29a in the process of cardiac hypertrophy and the changes of cell cycle related protein expression patterns in hypertrophic cardiomyocytes. H9C2 cardiomyocytes were induced with AngII at concentrations of 1 × 10⁻⁵、1 × 10⁻⁶ and 1 × 1⁻⁷ mol/L for 48 h, the cell area and total protein content were detected. The expression levels of miR-29a, Cyclin A2, Bcl-2 and Plk-1 in different groups were detected by qPCR. The results showed that after 48 h of induction with a concentration of 1 × 10⁻⁵ and1 × 10⁻⁶ mol/L, the cell area increased significantly, the total protein content of the cells also increased, and the expression level of miR-29a was significantly increased. The expression levels of Cyclin A2, Bcl-2 and Plk-1 increased after AngII induction at high concentration (1 × 10⁻⁵ mol/L), while decreased after at low concentration (1 × 1⁻⁷). Mir-29a may inhibit cell cycle related genes during the establishment of hypertrophic myocardium model.