General practice medicine, Huanggang Central Hospital of Yangtze University, Huanggang, China.
Department of central laboratory, Renmin hospital of Wuhan university, Wuhan, China.
BMC Cardiovasc Disord. 2024 Aug 5;24(1):406. doi: 10.1186/s12872-024-04070-z.
Myocardial infarction (MI) is a major disease with high morbidity and mortality worldwide. However, existing treatments are far from satisfactory, making the exploration of potent molecular targets more imperative. The E3 ubiquitin ligase RING finger protein 5 (RNF5) has been previously reported to be involved in several diseases by regulating ubiquitination-mediated protein degradation. Nevertheless, few reports have focused on its function in cardiovascular diseases, including MI.
In this study, we established RNF5 knockout mice through precise CRISPR-mediated genome editing and utilized left anterior descending coronary artery ligation in 9-11-week-old male C57BL/6 mice. Subsequently, serum biochemical analysis and histopathological examination of heart tissues were performed. Furthermore, we engineered adenoviruses for modulating RNF5 expression and subjected neonatal rat cardiomyocytes to oxygen-glucose deprivation (OGD) to mimic ischemic conditions, demonstrating the impact of RNF5 manipulation on cellular viability. Gene and protein expression analysis provided insights into the molecular mechanisms. Statistical methods were rigorously employed to assess the significance of experimental findings.
We found RNF5 was downregulated in infarcted heart tissue of mice and NRCMs subjected to OGD treatment. RNF5 knockout in mice resulted in exacerbated heart dysfunction, more severe inflammatory responses, and increased apoptosis after MI surgery. In vitro, RNF5 knockdown exacerbated the OGD-induced decline in cell activity, increased apoptosis, while RNF5 overexpression had the opposite effect. Mechanistically, it was proven that the kinase cascade initiated by apoptosis signal-regulating kinase 1 (ASK1) activation was closely regulated by RNF5 and mediated RNF5's protective function during MI.
We demonstrated the protective effect of RNF5 on myocardial infarction and its function was dependent on inhibiting the activation of ASK1, which adds a new regulatory component to the myocardial infarction associated network and promises to enable new therapeutic strategy.
心肌梗死（MI）是一种发病率和死亡率都很高的全球性重大疾病。然而，现有的治疗方法远不能令人满意，因此更迫切需要探索有效的分子靶点。E3 泛素连接酶 RING 指蛋白 5（RNF5）先前被报道通过调节泛素化介导的蛋白降解参与多种疾病。然而，很少有报道关注其在心血管疾病中的作用，包括 MI。
在这项研究中，我们通过精确的 CRISPR 介导的基因组编辑建立了 RNF5 敲除小鼠，并在 9-11 周龄的雄性 C57BL/6 小鼠中利用左前降支冠状动脉结扎。随后进行血清生化分析和心脏组织的组织病理学检查。此外，我们构建了调节 RNF5 表达的腺病毒，并使新生大鼠心肌细胞经历氧葡萄糖剥夺（OGD）以模拟缺血条件，证明了 RNF5 操作对细胞活力的影响。基因和蛋白表达分析提供了对分子机制的深入了解。严格运用统计学方法评估实验结果的显著性。
我们发现 RNF5 在小鼠梗死心肌组织和 OGD 处理的 NRCMs 中表达下调。在小鼠中敲除 RNF5 导致 MI 手术后心脏功能恶化、炎症反应更严重和凋亡增加。在体外，RNF5 敲低加剧了 OGD 诱导的细胞活性下降、凋亡增加，而 RNF5 过表达则产生相反的效果。机制上，证明了凋亡信号调节激酶 1（ASK1）激活引发的激酶级联反应受到 RNF5 的密切调控，介导了 RNF5 在 MI 中的保护功能。
我们证明了 RNF5 对心肌梗死的保护作用，其功能依赖于抑制 ASK1 的激活，这为与心肌梗死相关的网络增加了一个新的调节成分，并有望为新的治疗策略提供可能。
