Department of Cardiology, The First Affiliated Hospital,Hengyang Medical School, University of South China, Hengyang, China.
J Biochem Mol Toxicol. 2024 Sep;38(9):e23816. doi: 10.1002/jbt.23816.
Reperfusion strategies, the standard therapy for acute myocardial infarction (AMI), may result in ischemia/reperfusion (I/R) damage. Suppressor of cytokine signaling1 (SOCS1) exerts a cardioprotective function in myocardial I/R damage. Here, we investigated epigenetic modulators that deregulate SOCS1 in cardiomyocytes under hypoxia/reoxygenation (H/R) conditions. Human AC16 cardiomyocytes were exposed to H/R conditions to generate a cell model of myocardial I/R damage. Expression of mRNA and protein was detected by quantitative PCR and western blot analysis, respectively. Cell migratory and invasive abilities were evaluated by transwell assay. Cell apoptosis and M2 macrophage polarization were assessed by flow cytometry. TNF-α, IL-1β, and IL-6 levels were examined by ELISA. The interaction of KLF4 with SOCS1 was verified by chromatin immunoprecipitation and luciferase assays. SOCS1 and transcription factor KLF4 protein levels were underexpressed by 75% and 57%, respectively, in H/R-exposed AC16 cardiomyocytes versus control cells. Under H/R conditions, forced SOCS1 expression (2.7 times) induced cell migration (2.2 times) and invasion (1.9 times) and hindered cell apoptosis (by 45%) of AC16 cardiomyocytes as well as enhanced M2 macrophage polarization (4.6 times). Mechanistically, KLF4 upregulation promoted SOCS1 transcription (2.6 times) and expression (2.6 times) by binding to the SOCS1 promoter. Decrease of SOCS1 (by 51%) reversed the effects of KLF4 upregulation on cardiomyocyte migration, invasion and apoptosis, and M2 macrophage polarization under H/R conditions. Additionally, SOCS1 and KLF4 were underexpressed by 56% and 63%, respectively, in AMI serum. Our study indicates that KLF4-induced upregulation of SOCS1 can attenuate H/R-triggered apoptosis of AC16 cardiomyocytes and enhance M2 macrophage polarization.
再灌注策略是急性心肌梗死（AMI）的标准治疗方法，但可能导致缺血/再灌注（I/R）损伤。细胞因子信号转导抑制因子 1（SOCS1）在心肌 I/R 损伤中发挥心脏保护作用。在这里，我们研究了在低氧/复氧（H/R）条件下，调节心肌细胞中 SOCS1 的表观遗传调节剂。将人 AC16 心肌细胞暴露于 H/R 条件下，生成心肌 I/R 损伤的细胞模型。通过定量 PCR 和 Western blot 分析分别检测 mRNA 和蛋白的表达。通过 Transwell 测定评估细胞迁移和侵袭能力。通过流式细胞术评估细胞凋亡和 M2 巨噬细胞极化。通过 ELISA 检测 TNF-α、IL-1β 和 IL-6 水平。通过染色质免疫沉淀和荧光素酶测定验证 KLF4 与 SOCS1 的相互作用。与对照细胞相比，H/R 暴露的 AC16 心肌细胞中 SOCS1 和转录因子 KLF4 蛋白水平分别下调 75%和 57%。在 H/R 条件下，强制表达 SOCS1（2.7 倍）可诱导 AC16 心肌细胞的迁移（2.2 倍）和侵袭（1.9 倍），并抑制细胞凋亡（45%），同时增强 M2 巨噬细胞极化（4.6 倍）。在机制上，KLF4 的上调通过与 SOCS1 启动子结合促进 SOCS1 的转录（2.6 倍）和表达（2.6 倍）。在 H/R 条件下，SOCS1 减少（51%）逆转了 KLF4 上调对心肌细胞迁移、侵袭和凋亡以及 M2 巨噬细胞极化的影响。此外，在 AMI 血清中，SOCS1 和 KLF4 的表达分别下调 56%和 63%。我们的研究表明，KLF4 诱导的 SOCS1 上调可减轻 H/R 引起的 AC16 心肌细胞凋亡，并增强 M2 巨噬细胞极化。
