BoRanyi BaYinchahan, Lv Xinwei, Xiao Dong
Department of Critical Care Medicine, People's Hospital of Xinjiang Uygur Autonomous Region, Xinjiang Uygur Autonomous Region, NO.91 Tianchi Road, Tianshan District, Urumqi, 830001, China.
J Cardiothorac Surg. 2025 Jul 28;20(1):315. doi: 10.1186/s13019-025-03554-z.
Sepsis-induced myocardial injury (SIMI) leads to high morbidity and mortality. The 5-methylcytosine (mC) RNA methyltransferase NOL1/NOP2/SUN domain (NSUN)2 is a therapeutic target for many diseases. The purpose of this study was to investigate the role of NSUN2 in SIMI and the potential mechanism.
Both an in vivo cecum ligation and puncture (CLP) SIMI rat model and an in vitro lipopolysaccharide (LPS)-treated H9c2 cardiomyocytes model were established. Reverse transcription (RT)-quantitative polymerase chain reaction (qPCR) was used to detect mC-related and ferroptosis-related mRNA levels. Enzyme-linked immunosorbent assay was performed to assess inflammatory cytokines levels. Ferroptosis-related indicators were detected by commercial kits and Western blot. Methylated RNA immunoprecipitation (MeRIP)-qPCR assay was performed to detect the mC level of ferroptosis-related mRNAs. RIP assay was used to explore the interaction between NSUN2 and nuclear receptor coactivator (NCOA)4. The mC site of NCOA4 was analyzed by dual-luciferase reporter assay.
NSUN2 alleviated LPS-induced SIMI by increasing cell viability and inhibiting inflammation and ferroptosis. In addition, NSUN2 inhibited NCOA4 expression in a mC-dependent manner. Moreover, overexpressing NCOA4 downregulated cell viability and upregulated LDH activity, inflammation, and ferroptosis in LPS-induced SIMI. In in vivo studies, NSUN2 overexpression reversed CLP-induced myocardial injury, cardiac dysfunction, inflammation, and ferroptosis.
NSUN2 inhibited NCOA4 expression to alleviate ferroptosis and inflammation in SIMI in a mC manner, which might provide new information for the clinical treatment of SIMI.
脓毒症诱导的心肌损伤（SIMI）导致高发病率和死亡率。5-甲基胞嘧啶（mC）RNA甲基转移酶NOL1/NOP2/SUN结构域（NSUN）2是许多疾病的治疗靶点。本研究旨在探讨NSUN2在SIMI中的作用及潜在机制。
建立体内盲肠结扎穿孔（CLP）SIMI大鼠模型和体外脂多糖（LPS）处理的H9c2心肌细胞模型。采用逆转录（RT）-定量聚合酶链反应（qPCR）检测mC相关和铁死亡相关mRNA水平。进行酶联免疫吸附测定以评估炎性细胞因子水平。通过商业试剂盒和蛋白质免疫印迹法检测铁死亡相关指标。采用甲基化RNA免疫沉淀（MeRIP）-qPCR测定法检测铁死亡相关mRNA的mC水平。采用RNA免疫沉淀（RIP）测定法探究NSUN2与核受体辅激活因子（NCOA）4之间的相互作用。通过双荧光素酶报告基因测定法分析NCOA4的mC位点。
NSUN2通过提高细胞活力、抑制炎症和铁死亡来减轻LPS诱导的SIMI。此外，NSUN2以mC依赖的方式抑制NCOA4表达。而且，过表达NCOA4可下调LPS诱导的SIMI中的细胞活力，并上调乳酸脱氢酶（LDH）活性、炎症和铁死亡。在体内研究中，NSUN2过表达可逆转CLP诱导的心肌损伤、心脏功能障碍、炎症和铁死亡。
NSUN2以mC方式抑制NCOA4表达，减轻SIMI中的铁死亡和炎症，这可能为SIMI的临床治疗提供新信息。
