Department of Cardiology, The First Affiliated Hospital of Nanchang University, No. 17, Yong Waizheng Road, Donghu District, Nanchang, 330006, Jiangxi Province, People's Republic of China.
Department of Emergency, The First Affiliated Hospital of Nanchang University, Nanchang, 330006, Jiangxi Province, People's Republic of China.
Mol Cell Biochem. 2024 Apr;479(4):929-940. doi: 10.1007/s11010-023-04754-8. Epub 2023 May 31.
Previous reports have confirmed that miR-206 participates in inflammatory cardiomyopathy, but its definite mechanism remains elusive. This study aims to elucidate the potential mechanism of miR-206 in septic cardiomyopathy (SCM). The primary mouse cardiomyocytes were isolated and exposed to lipopolysaccharides (LPS) to construct a septic injury model in vitro. Then, the gene transcripts and protein levels were detected by RT-qPCR and/or Western blot assay. Cell proliferation, apoptosis, and inflammatory responses were evaluated by CCK-8/EdU, flow cytometry, and ELISA assays, respectively. Dual luciferase assay, Co-IP, and ubiquitination experiments were carried out to validate the molecular interactions among miR-206, USP33, and JAK2/STAT3 signaling. miR-206 was significantly downregulated, but USP33 was upregulated in LPS-induced cardiomyocytes. Gain-of-function of miR-206 elevated the proliferation but suppressed the inflammatory responses and apoptosis in LPS-induced cardiomyocytes. USP33, as a member of the USP protein family, was confirmed to be a direct target of miR-206 and could catalyze deubiquitination of JAK2 to activate JAK2/STAT3 signaling. Rescue experiments presented that neither upregulation of USP33 nor JAK2/STAT3 signaling activation considerably reversed the protective effects of miR-206 upregulation in LPS-induced cardiomyocytes. The above data showed that miR-206 protected cardiomyocytes from LPS-induced inflammatory injuries by targeting the USP33/JAK2/STAT3 signaling pathway, which might be a novel target for SCM treatment.
先前的报告已经证实，miR-206 参与了炎症性心肌病，但它的确切机制仍不清楚。本研究旨在阐明 miR-206 在脓毒症性心肌病 (SCM) 中的潜在机制。原代小鼠心肌细胞分离后用脂多糖 (LPS) 体外处理，构建脓毒症损伤模型。然后通过 RT-qPCR 和/或 Western blot 检测基因转录物和蛋白水平。通过 CCK-8/EdU、流式细胞术和 ELISA 分别评估细胞增殖、凋亡和炎症反应。双荧光素酶报告、Co-IP 和泛素化实验验证了 miR-206、USP33 和 JAK2/STAT3 信号之间的分子相互作用。miR-206 在 LPS 诱导的心肌细胞中显著下调，而 USP33 则上调。miR-206 的功能获得实验增加了 LPS 诱导的心肌细胞的增殖，但抑制了其炎症反应和凋亡。USP33 作为 USP 蛋白家族的一员，被确认为 miR-206 的直接靶标，可催化 JAK2 的去泛素化激活 JAK2/STAT3 信号。挽救实验表明，上调 USP33 或激活 JAK2/STAT3 信号都不能显著逆转 miR-206 上调对 LPS 诱导的心肌细胞的保护作用。上述数据表明，miR-206 通过靶向 USP33/JAK2/STAT3 信号通路保护心肌细胞免受 LPS 诱导的炎症损伤，这可能是 SCM 治疗的一个新靶点。
