Hypoxic pulmonary hypertension (HPH) is a devastating disease characterized by progressive vasoconstriction and vascular remodeling. Pirfenidone (PFD) inhibits the progression of HPH, though the molecular mechanisms remain unknown. This study is aimed at determining the role and mechanism of PFD in HPH in human pulmonary artery adventitial fibroblasts (HPAAFs), which were cultured under normal or hypoxic conditions. NOX4 and Rac1 were inhibited or overexpressed by shRNA or pcDNA3.1, respectively. Proliferation of HPAAFs was quantified by colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assays to assess cellular metabolic activity, cell counts, and ethynyldeoxyuridine (EdU) assays to detect DNA synthesis. Migration of HPAAFs was assessed by a wound healing assay. The expression levels of smooth muscle alpha-actin (a-SMA) and procollagen I (COL1A1) were assessed by RT-PCR and western blot analysis. PFD suppressed hypoxia-induced proliferation and migration of HPAAFs. Compared with the hypoxic control group, PFD reduced the expression of a-SMA and procollagen I (COL1A1). PFD reduced hypoxia-induced phosphorylation of p38 through the NOX4/reactive oxygen species (ROS) signaling pathway. Moreover, Rac1 also decreased hypoxia-induced phosphorylation of p38, without any cross-interaction with NOX4. These findings demonstrate that PFD is a novel therapeutic agent to prevent cell proliferation, migration, and fibrosis, which might be useful in inhibiting vascular remodeling in patients with HPH.

中文翻译：

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吡非尼酮通过NADPH / ROS / p38途径抑制肺动脉新生成纤维细胞中的低氧性肺动脉高压。

缺氧性肺动脉高压（HPH）是一种破坏性疾病，其特征是进行性血管收缩和血管重塑。吡非尼酮（PFD）抑制HPH的进程，尽管其分子机制仍然未知。这项研究旨在确定PFD在正常或低氧条件下培养的人肺动脉外膜成纤维细胞（HPAAF）中HPH中的作用和机制。NOX4和Rac1分别被shRNA或pcDNA3.1抑制或过表达。通过比色3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四唑（MTT）测定法定量HPAAF的增殖，以评估细胞代谢活性，细胞计数和乙炔基脱氧尿苷（EdU）测定法，以检测DNA合成。HPAAF的迁移通过伤口愈合试验评估。通过RT-PCR和Western blot分析评估平滑肌α-肌动蛋白（a-SMA）和胶原蛋白I（COL1A1）的表达水平。PFD抑制缺氧诱导的HPAAF的增殖和迁移。与缺氧对照组相比，PFD降低了a-SMA和原胶原I（COL1A1）的表达。PFD通过NOX4 /活性氧（ROS）信号通路减少了缺氧诱导的p38磷酸化。此外，Rac1还减少了缺氧诱导的p38磷酸化，而与NOX4没有任何交叉相互作用。这些发现表明，PFD是防止细胞增殖，迁移和纤维化的新型治疗剂，可能对抑制HPH患者的血管重塑有用。PFD抑制缺氧诱导的HPAAF的增殖和迁移。与缺氧对照组相比，PFD降低了a-SMA和原胶原I（COL1A1）的表达。PFD通过NOX4 /活性氧（ROS）信号通路减少了缺氧诱导的p38磷酸化。此外，Rac1还减少了缺氧诱导的p38磷酸化，而与NOX4没有任何交叉相互作用。这些发现表明，PFD是防止细胞增殖，迁移和纤维化的新型治疗剂，可能对抑制HPH患者的血管重塑有用。PFD抑制缺氧诱导的HPAAF的增殖和迁移。与缺氧对照组相比，PFD降低了a-SMA和原胶原I（COL1A1）的表达。PFD通过NOX4 /活性氧（ROS）信号传导途径减少了缺氧诱导的p38磷酸化。此外，Rac1还减少了缺氧诱导的p38磷酸化，而与NOX4没有任何交叉相互作用。这些发现表明，PFD是防止细胞增殖，迁移和纤维化的新型治疗剂，可能对抑制HPH患者的血管重塑有用。Rac1还减少了缺氧诱导的p38磷酸化，而与NOX4没有任何交叉相互作用。这些发现表明，PFD是防止细胞增殖，迁移和纤维化的新型治疗剂，可能对抑制HPH患者的血管重塑有用。Rac1还减少了缺氧诱导的p38磷酸化，而与NOX4没有任何交叉相互作用。这些发现表明，PFD是防止细胞增殖，迁移和纤维化的新型治疗剂，可能对抑制HPH患者的血管重塑有用。