Abstract：
Platelet-derived growth factor (PDGF) is one of the most important cytokines associated with pulmonary vascular remodeling in pulmonary arterial hypertension (PAH). PDGF receptor (PDGFR) inhibition exerted therapeutic effects on PAH in clinical trials, but serious side effects warrant the withdrawal of existing drugs. In this study, a novel highly selective PDGFR inhibitor WQ-C-401 was developed, and its effects on PDGFR signaling pathway and pulmonary vascular remodeling in PAH were investigated. Cell proliferation assays and Western blot analysis of PDGFRα/β phosphorylation showed that WQ-C-401 inhibited PDGFR-mediated cell proliferation assay and suppressed PDGFR phosphorylation in a concentration-dependent manner. DiscoverX\'s KinomeScanTM technology confirmed the good kinome selectivity of WQ-C-401 (S score (1) of PDGFR = (0.01)). In monocrotaline (MCT)-induced PAH rats, intragastric administration of WQ-C-401 (25, 50, 100 mg/kg/d) or imatinib (50 mg/kg/d, positive control) significantly decreased right ventricular systolic pressure (RVSP). Histological analysis demonstrated that WQ-C-401 inhibited pulmonary vascular remodeling by reducing muscularization and fibrosis, as well as alleviated right ventricular hypertrophy in MCT-treated rats. In addition, WQ-C-401 suppressed MCT-induced cell hyperproliferation and CD68+ macrophage infiltration around the pulmonary artery. In vitro, WQ-C-401 inhibited PDGF-BB-induced proliferation and migration of human pulmonary arterial smooth muscle cells (PASMCs). Moreover, Western blot analysis showed that WQ-C-401 concertration-dependently inhibited PDGF-BB-induced phosphorylation of ERK1/2 and PDGFRβ Y751, decreased collagen Ⅰ synthesis and increased alpha smooth muscle actin (α-SMA) expression in PASMCs. Collectively, our results suggest that WQ-C-401 is a selective and potent PDGFR inhibitor which could be a promising drug for the therapeutics of PAH by preventing pulmonary vascular remodeling.
摘要：
血小板衍生生长因子(PDGF)是肺动脉高压(PAH)中与肺血管重构相关的重要细胞因子之一。PDGF受体（PDGFR）抑制在临床试验中对PAH产生治疗作用，但是严重的副作用需要停用现有药物。在这项研究中,开发了一种新型的高选择性PDGFR抑制剂WQ-C-401，研究其对PAH中PDGFR信号通路和肺血管重构的影响。细胞增殖测定和PDGFRα/β磷酸化的蛋白质印迹分析显示WQ-C-401以浓度依赖性方式抑制PDGFR介导的细胞增殖测定并抑制PDGFR磷酸化。DiscoverX的KinomeScanTM技术证实了WQ-C-401良好的运动学选择性(PDGFR的S评分(1)=(0.01))。在野百合碱（MCT）诱导的PAH大鼠中，WQ-C-401（25、50、100mg/kg/d）或伊马替尼（50mg/kg/d，阳性对照)显著降低右心室收缩压(RVSP)。组织学分析表明，WQ-C-401通过减少肌肉化和纤维化抑制肺血管重塑，以及减轻MCT治疗大鼠的右心室肥厚。此外,WQ-C-401抑制MCT诱导的细胞过度增殖和肺动脉周围CD68+巨噬细胞浸润。体外，WQ-C-401抑制PDGF-BB诱导的人肺动脉平滑肌细胞(PASMC)增殖和迁移。此外，westernblot分析表明，WQ-C-401协同依赖性地抑制PDGF-BB诱导的ERK1/2和PDGFRβY751磷酸化，减少胶原蛋白Ⅰ的合成，增加PASMC中α-平滑肌肌动蛋白（α-SMA）的表达。总的来说，我们的结果表明,WQ-C-401是一种选择性和有效的PDGFR抑制剂,它可能是通过预防肺血管重塑治疗PAH的有前景的药物.
