Wang Jian, An Yucheng, Lin Jun, Tang Gang
Department of Cardiology, The Third Affiliated Hospital of Chongqing Medical University (Jieer Hospital), Chongqing, China.
Ann Transl Med. 2022 Jul;10(14):780. doi: 10.21037/atm-22-1894.
This study explored the effects of microRNA(miR)-194 on chronic cardiac hypertrophy (CH) induced by isoproterenol (ISO). The potential mechanism through regulation of the calcineurin A (CnA)/nuclear factor of activated T cells (NFAT) c2 pathway was investigated in the rat cardiomyoblast cell line H9c2.
H9c2 cells were treated with ISO to induce cardiomyocyte hypertrophy to simulate CH . The cell surface area was assessed by phalloidin staining. The expression of miR-194, CnA mRNA, and CnA protein were assessed. Furthermore, the cellular localization of the NFATc2 protein after induction of CH was detected. The relationship between miR-194 and the CnA mRNA 3'-untranslated region (UTR) was verified by dual luciferase report assays. By constructing cardiomyocyte cell models with low expression of miR-194 and/or CnA, the effects of miR-194 and CnA on the localization of the NFATc2 protein and cell hypertrophy was investigated. Rescue experiments were conducted to analyze whether overexpression of miR-194 could alleviate the cell hypertrophy induced by ISO.
The results demonstrated that induction with ISO significantly increased the surface area of H9c2 cells. After induction, the expression of miR-194 decreased, while both CnA mRNA and protein expression increased. Furthermore, the nuclear translocation of NFATc2 was obvious. MiR-194 bound to the 3'-UTR of CnA mRNA and inhibited CnA protein expression. Inhibition of miR-194 expression activated NFATc2 protein expression and increased the H9c2 cell surface area. After CnA expression was disturbed, hypertrophy induced by miR-194 down-regulation was blocked. In addition, overexpression of miR-194 significantly alleviated cell hypertrophy and activation of the CnA/NFATc2 pathway caused by ISO.
In conclusion, increasing the expression of miR-194 can alleviate CH by targeting can and inhibiting the CnA/NFATc2 pathway.
本研究探讨了微小RNA（miR）-194对异丙肾上腺素（ISO）诱导的慢性心肌肥厚（CH）的影响。在大鼠心肌成纤维细胞系H9c2中研究了其通过调节钙调神经磷酸酶A（CnA）/活化T细胞核因子（NFAT）c2途径的潜在机制。
用ISO处理H9c2细胞以诱导心肌细胞肥大来模拟CH。通过鬼笔环肽染色评估细胞表面积。评估miR-194、CnA mRNA和CnA蛋白的表达。此外，检测CH诱导后NFATc2蛋白的细胞定位。通过双荧光素酶报告基因检测验证miR-194与CnA mRNA 3'-非翻译区（UTR）之间的关系。通过构建miR-194和/或CnA低表达的心肌细胞模型，研究miR-194和CnA对NFATc2蛋白定位和细胞肥大的影响。进行挽救实验以分析miR-194过表达是否能减轻ISO诱导的细胞肥大。
结果表明，ISO诱导显著增加了H9c2细胞的表面积。诱导后，miR-194表达降低，而CnA mRNA和蛋白表达均增加。此外，NFATc2的核转位明显。miR-194与CnA mRNA的3'-UTR结合并抑制CnA蛋白表达。抑制miR-194表达激活了NFATc2蛋白表达并增加了H9c2细胞表面积。CnA表达受干扰后，miR-194下调诱导的肥大被阻断。此外，miR-194过表达显著减轻了ISO引起的细胞肥大和CnA/NFATc2途径的激活。
总之，增加miR-194的表达可通过靶向CnA并抑制CnA/NFATc2途径来减轻CH。
