Department of Pharmacy at the Second Affiliated Hospital, and Department of Pharmacology at College of Pharmacy (National Key Laboratory of Frigid Zone Cardiovascular Diseases, Key Laboratory of Cardiovascular Research, Ministry of Education), Harbin Medical University, Harbin, 150086, China.
Institute of Clinical Pharmacology (The Heilongjiang Key Laboratory of Drug Research), Harbin Medical University, Harbin, 150086, China.
Acta Pharmacol Sin. 2024 Jul;45(7):1425-1437. doi: 10.1038/s41401-024-01306-8. Epub 2024 Jun 5.
Cardiac fibrosis is a pathological scarring process that impairs cardiac function. N-acetyltransferase 10 (Nat10) is recently identified as the key enzyme for the N4-acetylcytidine (ac4C) modification of mRNAs. In this study, we investigated the role of Nat10 in cardiac fibrosis following myocardial infarction (MI) and the related mechanisms. MI was induced in mice by ligation of the left anterior descending coronary artery; cardiac function was assessed with echocardiography. We showed that both the mRNA and protein expression levels of Nat10 were significantly increased in the infarct zone and border zone 4 weeks post-MI, and the expression of Nat10 in cardiac fibroblasts was significantly higher compared with that in cardiomyocytes after MI. Fibroblast-specific overexpression of Nat10 promoted collagen deposition and induced cardiac systolic dysfunction post-MI in mice. Conversely, fibroblast-specific knockout of Nat10 markedly relieved cardiac function impairment and extracellular matrix remodeling following MI. We then conducted ac4C-RNA binding protein immunoprecipitation-sequencing (RIP-seq) in cardiac fibroblasts transfected with Nat10 siRNA, and revealed that angiomotin-like 1 (Amotl1), an upstream regulator of the Hippo signaling pathway, was the target gene of Nat10. We demonstrated that Nat10-mediated ac4C modification of Amotl1 increased its mRNA stability and translation in neonatal cardiac fibroblasts, thereby increasing the interaction of Amotl1 with yes-associated protein 1 (Yap) and facilitating Yap translocation into the nucleus. Intriguingly, silencing of Amotl1 or Yap, as well as treatment with verteporfin, a selective and potent Yap inhibitor, attenuated the Nat10 overexpression-induced proliferation of cardiac fibroblasts and prevented their differentiation into myofibroblasts in vitro. In conclusion, this study highlights Nat10 as a crucial regulator of myocardial fibrosis following MI injury through ac4C modification of upstream activators within the Hippo/Yap signaling pathway.
心肌纤维化是一种病理性瘢痕形成过程，可损害心脏功能。N-乙酰转移酶 10（Nat10）最近被确定为 mRNA 的 N4-乙酰胞嘧啶（ac4C）修饰的关键酶。在这项研究中，我们研究了 Nat10 在心肌梗死后（MI）心脏纤维化中的作用及其相关机制。通过结扎左前降支冠状动脉诱导小鼠 MI，并通过超声心动图评估心功能。我们发现，在 MI 后 4 周，梗死区和交界区的 Nat10 mRNA 和蛋白表达水平均显著增加，MI 后心肌成纤维细胞中 Nat10 的表达明显高于心肌细胞。心肌成纤维细胞特异性过表达 Nat10 可促进胶原沉积，并诱导 MI 后小鼠心脏收缩功能障碍。相反，MI 后心肌成纤维细胞特异性敲除 Nat10 可显著减轻心脏功能障碍和细胞外基质重构。然后，我们对转染了 Nat10 siRNA 的心肌成纤维细胞进行了 ac4C-RNA 结合蛋白免疫沉淀测序（RIP-seq），结果表明，Hippo 信号通路的上游调节因子血管生成素样 1（Amotl1）是 Nat10 的靶基因。我们证明，Nat10 介导的 Amotl1 ac4C 修饰增加了其在新生心肌成纤维细胞中的 mRNA 稳定性和翻译，从而增加了 Amotl1 与 yes 相关蛋白 1（Yap）的相互作用，并促进了 Yap 向核内易位。有趣的是，沉默 Amotl1 或 Yap 以及用特异性和有效的 Yap 抑制剂 verteporfin 处理，可减弱 Nat10 过表达诱导的心肌成纤维细胞增殖，并防止其在体外分化为肌成纤维细胞。总之，这项研究强调了 Nat10 通过 Hippo/Yap 信号通路中的上游激活物的 ac4C 修饰，成为 MI 损伤后心肌纤维化的关键调节因子。
