Department of Cardiac Catheterization Room, Yantaishan Hospital, Yantai City, Shandong Province, 264008, China.
Department of Geriatric Cardiovascular Medicine, The Second People's Hospital of Lishui, Lishui City, Zhejiang Province, 323000, China.
J Physiol Pharmacol. 2024 Jun;75(3). doi: 10.26402/jpp.2024.3.03. Epub 2024 Jul 18.
Myocarditis (MC) is a myocardial inflammatory disease that threats human life. Pitavastatin (Pit) is a unique lipophilic statin with potent effects on lowering plasma total cholesterol and triacylglycerols. It has been reported to have pleiotropic effects, such as reducing inflammation and oxidative stress. However, the regulatory mechanism of Pit in MC remains a mystery. Two MC models were established in vitro (lipopolysaccharides-(LPS)-stimulated H9c2 cells) and in vivo (intraperitoneal injection of LPS in mice). The levels of microRNA-106b-5p (miR-106b-5p) and mitogen-activated protein kinase kinase kinase 2 (MAP3K2) were detected. ELISA was used to analyze in vivo cell inflammatory factors and myocardial injury markers, kits were used to detect the expression of antioxidant enzymes, cell counting kit-8 (CCK-8) was used to detect cell proliferation, and flow cytometry was used to detect apoptosis. Hematoxylin and eosin (HE) staining was used to detect the pathological changes of myocardial tissue in mice, and TUNEL staining was used to detect in vivo tissue cell apoptosis. The regulatory mechanism of Pit on miR-106b-5p/MAP3K2 was verified by a series of functional rescue experiments. The results demonstrated that in LPS-induced H9c2 cells, antioxidant enzymes decreased and pro-inflammatory factors and cardiac injury markers increased (p<0.05). However, these phenomenons were attenuated by Pit pretreatment. LPS decreased miR-106b-5p and elevated MAP3K2 in H9c2 cells, while Pit could recover their expression patterns (p<0.05). MAP3K2 was confirmed as a target gene of miR-106b-5p. Upregulating miR-106b-5p or downregulating MAP3K2 could further promote the protective effect of Pit, and vice versa (p<0.05). In addition, in the LPS-induced MC mouse model, histological examination showed that Pit significantly improved the myocardial tissue damage in MC mice, while downregulating miR-106b-5p or upregulating MAP3K2 could suppress the ameliorative effect of Pit (p<0.05). In conclusion, our study demonstrated that Pit ameliorates myocardial injury by suppressing myocardial inflammation and oxidative stress by modulating the miR-106b-5p/MAP3K2 axis.
心肌炎（MC）是一种威胁人类生命的心肌炎症性疾病。匹伐他汀（Pit）是一种独特的亲脂性他汀类药物，具有降低血浆总胆固醇和三酰甘油的强大作用。它已被报道具有多种作用，如减轻炎症和氧化应激。然而，Pit 在 MC 中的调节机制仍是一个谜。在体外（脂多糖（LPS）刺激的 H9c2 细胞）和体内（LPS 腹腔注射的小鼠）建立了两种 MC 模型。检测 microRNA-106b-5p（miR-106b-5p）和丝裂原活化蛋白激酶激酶激酶 2（MAP3K2）的水平。酶联免疫吸附试验（ELISA）用于分析体内细胞炎症因子和心肌损伤标志物，试剂盒用于检测抗氧化酶的表达，细胞计数试剂盒-8（CCK-8）用于检测细胞增殖，流式细胞术用于检测细胞凋亡。苏木精和伊红（HE）染色用于检测小鼠心肌组织的病理变化，TUNEL 染色用于检测体内组织细胞凋亡。通过一系列功能挽救实验验证了 Pit 对 miR-106b-5p/MAP3K2 的调节机制。结果表明，在 LPS 诱导的 H9c2 细胞中，抗氧化酶减少，促炎因子和心肌损伤标志物增加（p<0.05）。然而，这些现象被 Pit 预处理所减轻。LPS 降低了 H9c2 细胞中的 miR-106b-5p 和升高了 MAP3K2，而 Pit 可以恢复它们的表达模式（p<0.05）。MAP3K2 被确认为 miR-106b-5p 的靶基因。上调 miR-106b-5p 或下调 MAP3K2 可以进一步促进 Pit 的保护作用，反之亦然（p<0.05）。此外，在 LPS 诱导的 MC 小鼠模型中，组织学检查表明 Pit 显著改善了 MC 小鼠的心肌组织损伤，而下调 miR-106b-5p 或上调 MAP3K2 可以抑制 Pit 的改善作用（p<0.05）。总之，我们的研究表明，Pit 通过调节 miR-106b-5p/MAP3K2 轴抑制心肌炎症和氧化应激来改善心肌损伤。
