Wang Xiaojiao, Qu Jing, Li Dongxu, Li Junli, Wu Wenchao, Liu Xiaojing
Lab of Cardiovascular Diseases, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu 610041, P.R.China.
Department of Cardiac Surgery, West China Hospital, Sichuan University, Chengdu 610041, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2020 Apr 25;37(2):340-348. doi: 10.7507/1001-5515.201911049.
This study aimed to explore the role of miR-130a-3p in cardiomyocyte hypertrophy and its underlying mechanisms. Pressure-overload induced myocardial hypertrophy mice model was constructed by thoracic aortic constriction (TAC). , norepinephrine (NE) was used to stimulate neonatal rat cardiomyocytes (NRCMs) and H9c2 rat cardiomyocytes to induce hypertrophic phenotypes. The expression of miR-130a-3p was detected in mice hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. The mimics and inhibitors of miR-130a-3p were transfected into H9c2 cells to observe the role of miR-130a-3p on the hypertrophic phenotype change of cardiomyocytes separately. Furthermore, whether miR-130a-3p regulated hypertrophic related signaling pathways was explored. The results showed that the expression of miR-130a-3p was significantly decreased in hypertrophic myocardium, hypertrophic NRCMs and H9c2 cells. After transfection of miR-130a-3p mimics, the expression of hypertrophic marker genes, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC), and the cell surface area were notably down-regulated compared with the control group (mimics N.C. + NE group). But after transfection of miR-130a-3p inhibitor, the expression of ANP, BNP and β-MHC in H9c2 cells increased significantly, and the cell area increased further. By Western blot, it was found that the protein phosphorylation level of Akt and mTOR were down-regulated after over-expression of miR-130a-3p. These results suggest that miR-130a-3p mimics may alleviate the degree of cardiomyocyte hypertrophy, meanwhile its inhibitor can further aggravate cardiomyocyte hypertrophy. Over-expression of miR-130a-3p may attenuate cardiomyocytes hypertrophy by affecting the Akt pathway.
本研究旨在探讨miR-130a-3p在心肌细胞肥大中的作用及其潜在机制。通过胸主动脉缩窄（TAC）构建压力超负荷诱导的心肌肥大小鼠模型。此外，使用去甲肾上腺素（NE）刺激新生大鼠心肌细胞（NRCMs）和H9c2大鼠心肌细胞以诱导肥大表型。检测miR-130a-3p在小鼠肥厚心肌、肥厚NRCMs和H9c2细胞中的表达。将miR-130a-3p的模拟物和抑制剂转染到H9c2细胞中，分别观察miR-130a-3p对心肌细胞肥大表型变化的作用。此外，还探讨了miR-130a-3p是否调节肥大相关信号通路。结果显示，miR-130a-3p在肥厚心肌、肥厚NRCMs和H9c2细胞中的表达显著降低。转染miR-130a-3p模拟物后，与对照组（模拟物N.C. + NE组）相比，肥大标志物基因心房钠尿肽（ANP）、脑钠尿肽（BNP）和β-肌球蛋白重链（β-MHC）的表达以及细胞表面积显著下调。但转染miR-130a-3p抑制剂后，H9c2细胞中ANP、BNP和β-MHC的表达显著增加，细胞面积进一步增大。通过蛋白质免疫印迹法发现，miR-130a-3p过表达后Akt和mTOR的蛋白磷酸化水平下调。这些结果表明，miR-130a-3p模拟物可能减轻心肌细胞肥大程度，而其抑制剂可进一步加重心肌细胞肥大。miR-130a-3p过表达可能通过影响Akt通路减轻心肌细胞肥大。
