Investigating the molecular mechanisms of right ventricular failure in pulmonary hypertension

项目摘要 该项目建立在理解参与的精确分子机制的科学前提之上。 发生继发于肺动脉高压（PH）的右心室衰竭（RVF）。PH-RVF是一个重要的 PH的发病率和死亡率的预后决定因素，其特征在于重塑和纤维化。尽管 RV功能在PH中的重要性，继发于PH的RVF的机制细节仍然难以捉摸。虽然 目前针对肺血管的治疗确实为PH患者提供了一些功能改善，但没有 迄今为止，已批准的治疗方法可直接针对失败的RV。该项目的目标是突出 负责RV重塑和纤维化的特定分子机制，可作为新的靶点 PH引起的裂谷热的治疗策略。该提案利用最先进的RV批量RNA测序 两种严重PH临床前大鼠模型的分析，突出显示内皮细胞向间充质细胞转化 （EndMT）作为最高上调途径和Snai 1（Snail）作为新的网络枢纽促进了 RVF中EndMT与纤维化的关系通过Snai 1-LOXL 2-CTGF轴表达。本提案检验了PH-RVF是 与EndMT和Snai 1-LOXL 2-CTGF轴通过染色质重塑控制的纤维化相关， RV。靶向Snai 1和/或LOXL 2可作为PH-RVF的新治疗策略。该提案 目标：目标1。确定Snai 1-LOXL 2-CTGF轴在调节RV EndMT中的机制作用 在体内和体外的PH-RVF。目标二。确定Snai 1-LOXL 2-CTGF轴在调节 体内和体外PH-RVF中的RV纤维化。目标3。研究Snai 1和/或LOXL 2的机制基础 作为PH-RVF的体内和体外新治疗策略的基因敲减。拟议的研究意义重大， 因为它们将突出在体内和体外靶向Snai 1及其相关网络以抑制 EndMT和纤维化和拯救裂谷热。拟议的研究是创新的，因为它们将采用组织/细胞- 特异性分析，以鉴定和表征受组织/细胞高度调节的新型治疗靶点- 在PH诱导RVF大鼠RV中特异性Snai 1/LOXL 2敲低/过表达（体内研究）， 以及在人冠状动脉内皮细胞和人心脏中Snai 1/LOXL 2敲低/过表达， 成纤维细胞（体外研究）。拟议的研究完成后，将查明和处理 目前在PH诱导裂谷热发生的分子基础方面存在知识空白。调查结果会显示 对Snai 1及其合作伙伴在RVF RV重塑中的作用的重要见解，并可能导致 开发新的RV特异性治疗策略。

PROJECT SUMMARY This project builds on the scientific premise of understanding the precise molecular mechanisms involved in the development of right ventricular failure (RVF) secondary to pulmonary hypertension (PH). PH-RVF is a significant prognostic determinant of morbidity and mortality in PH and is characterized by remodeling and fibrosis. Despite the importance of RV function in PH, the mechanistic details of RVF secondary to PH remain elusive. Although current therapies targeting pulmonary vasculature do offer some functional improvement for PH patients, yet no approved therapies are available till date that directly target the failing RV. The goal of this project is to highlight specific molecular mechanisms responsible for remodeling and fibrosis in the RV that may be targeted as novel therapeutic strategies for PH-induced RVF. This proposal utilizes state-of-the-art RV bulk-RNA sequencing analysis from two pre-clinical rat models of severe PH highlighting endothelial-to-mesenchymal-transition (EndMT) as the top upregulated pathway and Snai1 (Snail) as a novel network hub promoting the development of EndMT and fibrosis in RVF via Snai1-LOXL2-CTGF axis. This proposal tests the hypothesis that PH-RVF is associated with EndMT and fibrosis governed by Snai1-LOXL2-CTGF axis through chromatin remodeling in the RV. Targeting Snai1 and/or LOXL2 could serve as novel therapeutic strategies for PH-RVF. The proposal has the following aims: Aim 1. Determine the mechanistic role of Snai1-LOXL2-CTGF axis in regulating RV EndMT in PH-RVF in vivo and in vitro. Aim 2. Determine the mechanistic role of Snai1-LOXL2-CTGF axis in regulating RV fibrosis in PH-RVF in vivo and in vitro. Aim 3. Investigate the mechanistic basis of Snai1 and/or LOXL2 knockdown as novel therapeutic strategies for PH-RVF in vivo and in vitro. The proposed studies are significant, since they will highlight the importance of targeting Snai1 and its related network in vivo and in vitro to inhibit EndMT and fibrosis and rescue RVF. The proposed studies are innovative, since they will employ tissue/cell- specific analysis to identify and characterize novel therapeutic targets that are highly regulated by tissue/cell- specific Snai1/LOXL2 knockdown/overexpression in the RVs of rats with PH-induced RVF (in vivo studies) as well as Snai1/LOXL2 knockdown/overexpression in human coronary artery endothelial cells, and human cardiac fibroblasts (in vitro studies). Upon completion, the proposed studies will have identified and addressed the current gap in knowledge in the molecular basis of development of PH-induced RVF. The investigations will yield important insights into the role of Snai1 and its co-partners in RV remodeling in RVF and may lead to development of novel RV-specific therapeutic strategies.