Department of Respiratory Medicine, Suzhou Science & Technology Town Hospital, Suzhou, 215153, Jiangsu, China.
Department of Respiratory Medicine, People's Hospital of Ningxia Hui Autonomous Region, The Affiliated Hospital of NingXia Medical University, Ningxia, Yinchuan, 750001, China.
Respir Res. 2023 Mar 24;24(1):92. doi: 10.1186/s12931-023-02387-5.
Pulmonary hypertension (PH) is a devastating disease characterized by vasoconstriction and vascular remodeling, leading to right ventricular failure and death. PH is a common complication of chronic obstructive pulmonary disease (COPD). Accumulating evidence demonstrate that microRNAs participate in the pathobiology of PH in COPD patients. In this study, we aimed to evaluate the expression and function of microRNA-4640-5p (miR-4640-5p) in PH.
The mRNA and protein levels were determined by quantitative polymerase chain reaction (qPCR) and western blot, separately. Functional assays and western blot were performed to determine the effects of miR-4640-5p and NOS1 on cell growth, migration. Besides, the dual-luciferase reporter assays were used to validate miR-4640-5p and NOS1 interactions.
We found that miR-4640-5p expression was significantly higher in the lung tissues of COPD-PH patients than in the healthy controls while higher expression of miR-4640-5p was correlated with more severe COPD-PH. By using pulmonary artery smooth muscle cell (PASMC) in in vitro assays, we demonstrated that inhibition of miR-4640-5p suppressed cell proliferation and migration of PASMC via regulating mTOR/S6 signaling. Bioinformatics analysis and validation experiments revealed that nitric oxide synthase 1 (NOS1) was a direct downstream target of miR-4640-5p. Overexpression of NOS1 partially antagonized the effect of miR-4640-5p in regulating PASMC cell proliferation and migration. In addition, our findings suggested that miR-4640-5p/NOS1 axis regulated mitochondrial dynamics in PASMCs. Furthermore, in the hypoxia-induced PH rat model, inhibition of miR-4640-5p ameliorated PH with reduced right ventricular systolic pressure and Fulton index.
miR-4640-5p regulates PH via targeting NOS1, which provides a potential diagnostic biomarker and therapeutic target for COPD-PH patients.
肺动脉高压（PH）是一种以血管收缩和血管重构为特征的破坏性疾病，导致右心衰竭和死亡。PH 是慢性阻塞性肺疾病（COPD）的常见并发症。越来越多的证据表明，microRNA 参与 COPD 患者 PH 的病理生物学过程。在这项研究中，我们旨在评估 microRNA-4640-5p（miR-4640-5p）在 PH 中的表达和功能。
通过定量聚合酶链反应（qPCR）和 Western blot 分别测定 mRNA 和蛋白质水平。进行功能测定和 Western blot 以确定 miR-4640-5p 和 NOS1 对细胞生长、迁移的影响。此外，还使用双荧光素酶报告基因实验来验证 miR-4640-5p 和 NOS1 之间的相互作用。
我们发现，与健康对照组相比，COPD-PH 患者的肺组织中 miR-4640-5p 的表达明显升高，而 miR-4640-5p 的高表达与更严重的 COPD-PH 相关。通过体外肺动脉平滑肌细胞（PASMC）实验，我们证明抑制 miR-4640-5p 通过调节 mTOR/S6 信号通路抑制 PASMC 的增殖和迁移。生物信息学分析和验证实验表明，一氧化氮合酶 1（NOS1）是 miR-4640-5p 的直接下游靶标。NOS1 的过表达部分拮抗了 miR-4640-5p 调节 PASMC 细胞增殖和迁移的作用。此外，我们的研究结果表明，miR-4640-5p/NOS1 轴调节 PASMC 中的线粒体动力学。此外，在缺氧诱导的 PH 大鼠模型中，抑制 miR-4640-5p 可改善 PH，降低右心室收缩压和 Fulton 指数。
miR-4640-5p 通过靶向 NOS1 调节 PH，为 COPD-PH 患者提供了一个潜在的诊断生物标志物和治疗靶点。
