Role of tyrosine kinases in the pathogenesis of pulmonary arterial hypertension

酪氨酸激酶在肺动脉高压发病机制中的作用

• 批准号: 234334212
• 负责人: Professor Dr. Ralph Schermuly
• 金额: --
• 依托单位: Biomedizinisches Forschungszentrum Seltersberg (BFS)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/234334212?language=en
• 关键词: Role; tyrosine; kinases; pathogenesis; pulmonary

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by sustained elevation of pulmonary vascular resistance leading to increased right ventricular (RV) afterload and RV hypertrophy that culminate in RV failure and death. Pulmonary vascular remodeling, the key pathological feature of PAH, is attributable to the increased proliferation and resistance to apoptosis of pulmonary vascular cells. Several growth factors are implicated in the abnormal vascular cell phenotypes. Growth factors bind to their receptor tyrosine kinase (RTK) and initiate downstream signaling pathways that result in cell proliferation and survival. An effective therapeutic strategy should therefore target these abnormal vascular cells thereby interfering and reversing the remodeled pulmonary vasculature. Current vasodilatory therapies mainly provide symptomatic relief and convincing evidence of their direct anti-proliferative/anti-remodeling effects on severely remodeled vessels is largely missing. In the previous funding period, we have shown that inhibition of the platelet derived growth factor receptor (PDGFR) by imatinib reverses vascular remodeling and improved survival in experimental PH. Based on our work, imatinib successfully underwent clinical development in PAH which resulted in a positive phase 3 trial. However, the role of PDGF and growth factor-mediated RTK signaling has still to be elucidated. The project therefore aims to a) analyze the cell- and compartment-specific expression of growth factors and their signaling molecules (Src, PI3K, mTOR, JAK, ERK, P38, JNK, AKT, PLCy and PKC) in experimental and human tissues using techniques such as laser assisted microdissection, real-time PCR, in situ hybridization, immunofluorescence and immunohistochemistry, b) examine the functional role of these molecules on proliferation and apoptosis of primary vascular cells using small molecule inhibitors and siRNA techniques, c) investigate the cell type-specific (endothelial versus smooth-muscle) role of these molecules in PH pathogenesis by employing transgenic animals and d) evaluate the therapeutic efficacy of inhibitors of RTK pathways in clinically relevant animal models of PH. The PH will be assessed using non-invasive imaging techniques (echocardiography, CT-FMT), invasive techniques (Millar pulmonary artery catheter) and histomorphometry. The effects of imatinib therapy will be examined e) by various treatment modes (pulsed vs. continuous), and additionally in the model of pulmonary stenosis. The efficacy of various inhibitors of RTKs administered locally via inhalation will also be explored. Finally, f) the potential indicators/markers of individual responsiveness of PAH patients to TK inhibitors (imatinib) will be analyzed using clinical samples. The overall goal of this project is to further develop the concept that the remodeled vasculature in PH can be reversed/ normalized by targeting RTK signaling pathways.

肺动脉高压（PAH）是一种进行性疾病，其特征是肺血管阻力持续升高，导致右心室后负荷增加和右心室肥厚，最终导致右心室衰竭和死亡。肺血管重构是PAH的主要病理特征，其原因是肺血管细胞增殖和抗凋亡能力增强。几种生长因子与异常的血管细胞表型有关。生长因子与其受体酪氨酸激酶（RTK）结合并启动下游信号通路，导致细胞增殖和存活。因此，有效的治疗策略应该针对这些异常血管细胞，从而干扰和逆转重建的肺血管。目前的血管扩张疗法主要提供症状缓解，其对严重重构血管的直接抗增殖/抗重塑作用的令人信服的证据在很大程度上缺乏。在之前的资助期内，我们已经证明伊马替尼抑制血小板衍生生长因子受体（PDGFR）逆转血管重塑并提高实验性ph的生存率。基于我们的工作，伊马替尼成功地在PAH中进行了临床开发，并取得了积极的3期试验。然而，PDGF和生长因子介导的RTK信号的作用仍有待阐明。因此，该项目旨在a)利用激光辅助显微解剖、实时PCR、原位杂交、免疫荧光和免疫组织化学等技术，分析生长因子及其信号分子（Src、PI3K、mTOR、JAK、ERK、P38、JNK、AKT、PLCy和PKC）在实验和人体组织中的细胞和室特异性表达；b)利用小分子抑制剂和siRNA技术研究这些分子在原代血管细胞增殖和凋亡中的功能作用；c)通过转基因动物研究这些分子在PH发病机制中的细胞类型特异性（内皮细胞与平滑肌细胞）作用；d)在临床相关的PH动物模型中评估RTK通路抑制剂的治疗效果。PH将通过无创成像技术（超声心动图、CT-FMT）、有创技术（肺动脉导管）和组织形态学来评估。伊马替尼治疗的效果将通过各种治疗模式（脉冲与连续）进行检查，另外在肺狭窄模型中进行检查。通过吸入局部给药的各种RTKs抑制剂的疗效也将被探讨。最后，f)使用临床样本分析PAH患者对TK抑制剂（伊马替尼）个体反应性的潜在指标/标记。该项目的总体目标是进一步发展的概念，重塑的血管在PH可以通过靶向RTK信号通路逆转/正常化。