Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, PR China.
Department of Technology, Hebei University of Chinese Medicine, Shijiazhuang, PR China.
Phytomedicine. 2023 Sep;118:154923. doi: 10.1016/j.phymed.2023.154923. Epub 2023 Jun 16.
Continuous activation and inflammation of cardiac fibroblasts (CFs) are essential for myocardial fibrosis. Gentianella acuta (Michx.) Hiitonen (G. acuta), that contains xanthones with cardioprotective properties, a typical healthful herb extensively used to treat cardiovascular diseases in Inner Mongolia region of China. However, it remains unknown whether or not G. acuta-derived miRNAs can shield CFs from activation by inflammatory stimulation. Therefore, we tend to investigated the role and core mechanism of G. acuta-derived Gen-miR-1 in regulating fibrosis and inflammation induced by TGF-β1.
An animal model for myocardial infarction was built by subcutaneous injections of ISO and treated with Gen-miR-1 using intragastric administration. The protective effect of Gen-miR-1 on the heart was assessed by pathomorphological analysis of myocardial fibrosis. Using loss- and gain-of-function approaches, Gen-miR-1 regulation of HAX1/HMG20A/Smads axis was investigated by utilizing luciferase assay, Western blot, co-immunoprecipitation, etc. RESULTS: Screened and identified Gen-miR-1 from G. acuta. Gen-miR-1 can enter the mouse body, and markedly inhibit myocardial infarction induced by ISO in mice, as well as suppresses fibrosis in CFs and attenuates the inflammatory response elicited by TGF-β1 in vitro. Gen-miR-1 downregulates HCLS1-related Protein X-1 (HAX1) expression through direct binding to the 3' UTR of HAX1, which in turn relieves HAX1 from promoting the expression of high-mobility group protein 20A (HMG20A), whereas HMG20A downregulation restrains the activation of TGF-β1/Smads signaling pathways, subsequently resulting in a decrease of fibrosis and in facilitating CFs anti-inflammatory effects induced by Gen-miR-1 in the context of CFs activation induced by TGF-β1.
Our results first uncovered unique bioactive components in G. acuta and elucidated the molecular mechanism by which G. acuta-derived Gen-miR-1 suppress inflammation and myocardial fibrosis. These findings expand our understanding of G. acuta's therapeutic properties and bioactive constituents. Gen-miR-1-regulated HAX1/HMG20A/Smads axis will be one potential therapeutic target for cardiac remodeling.
心脏成纤维细胞（CFs）的持续激活和炎症是心肌纤维化的必要条件。獐芽菜（Gentianella acuta）（吉氏獐芽菜）含有具有心脏保护作用的紫檀芪，是一种广泛用于治疗中国内蒙古地区心血管疾病的典型健康草本植物。然而，目前尚不清楚獐芽菜来源的 miRNAs 是否可以保护 CFs 免受炎症刺激的激活。因此，我们倾向于研究獐芽菜衍生的 Gen-miR-1 在调节 TGF-β1 诱导的纤维化和炎症中的作用和核心机制。
通过皮下注射 ISO 构建心肌梗死动物模型，并通过灌胃给予 Gen-miR-1 进行治疗。通过心肌纤维化的病理形态学分析评估 Gen-miR-1 对心脏的保护作用。利用荧光素酶报告基因检测、Western blot、免疫共沉淀等方法，通过失活和激活功能方法研究 Gen-miR-1 对 HAX1/HMG20A/Smads 轴的调控。
从獐芽菜中筛选并鉴定出 Gen-miR-1。Gen-miR-1 可以进入小鼠体内，显著抑制 ISO 诱导的小鼠心肌梗死，并抑制 CFs 纤维化，减轻 TGF-β1 体外诱导的炎症反应。Gen-miR-1 通过直接结合 HAX1 的 3'UTR 下调 HCLS1 相关蛋白 X-1（HAX1）的表达，从而使 HAX1 从促进高迁移率族蛋白 20A（HMG20A）的表达中释放出来，而 HMG20A 的下调抑制了 TGF-β1/Smads 信号通路的激活，进而导致纤维化减少，并促进 Gen-miR-1 在 TGF-β1 诱导的 CFs 激活背景下诱导的 CFs 抗炎作用。
我们的研究结果首次揭示了獐芽菜中的独特生物活性成分，并阐明了獐芽菜衍生的 Gen-miR-1 抑制炎症和心肌纤维化的分子机制。这些发现扩展了我们对獐芽菜治疗特性和生物活性成分的理解。Gen-miR-1 调节的 HAX1/HMG20A/Smads 轴将成为心脏重构的一个潜在治疗靶点。
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