Targeted Rho kinase-1 KO Mouse Model for Vascular Smooth Muscle Remodeling

描述（由申请人提供）：血管平滑肌重构在几种肺部疾病的发展中起关键作用，包括肺动脉高压，一种最终导致心力衰竭的致命疾病。因此，有必要对这一领域进行研究。本研究的目的是通过建立和表征一种新的遗传小鼠模型来研究体内重塑过程的分子基础。这样的模型对于确定关键基因产物和随后的信号通路在疾病发病机制中的特殊作用是必要的。Rho GTPase及其主要作用Rho激酶（ROCK）介导许多血管平滑肌细胞反应，如收缩性和生长，这些反应也涉及重塑过程。培养细胞的数据显示，Rho/ROCK参与肺血管平滑肌细胞增殖和肌动蛋白细胞骨架变化。此外，ROCK还涉及啮齿类动物实验性肺动脉高压的发展。然而，许多体内数据是基于药物ROCK抑制剂（Y27632，法舒地尔）的使用，这些抑制剂不具有特异性；因此，ROCK在血管平滑肌重塑中的体内作用仍有待独立确定。有两个ROCK基因，我们的假设是rock1在血管平滑肌重塑和肺动脉高压发展中起着独特的作用，但尚未在遗传动物模型中进行研究。在此基础上，Specific Aim 1将产生一种独特的血管平滑肌靶向ROCK1基因敲除（KO）小鼠品系。特异性Aim 2将表征目标KO菌株的表型。目的2将包括基线和应激反应（如缺氧）的体内研究，以及培养的来自ROCK1KO菌株的血管平滑肌细胞的细胞和信号反应的研究。总的来说，Aims将产生并表征一种新的遗传ROCK动物模型，并在体内验证ROCK1参与重塑和肺动脉高压疾病的假设。

DESCRIPTION (provided by applicant): Vascular smooth muscle remodeling plays a key role in the development of several pulmonary diseases, including pulmonary hypertension, a fatal disease that culminates in heart failure. Thus, there is a need for research in this area. The objective of this proposal is to study the molecular basis of the remodeling process in vivo by generating and characterizing a novel genetic mouse model. Such models are necessary to define the particular role of key gene products and ensuing signaling pathways in disease pathogenesis. The Rho GTPase and its primary effect or, Rho kinase (ROCK), mediate many vascular smooth muscle cell responses such as contractility and growth which are also implicated in the remodeling process. Data in cultured cells have shown that Rho/ROCK participate in pulmonary vascular smooth muscle cell proliferation and acto-myosin cytoskeletal changes. Moreover, ROCK is implicated in the development of experimentally-induced pulmonary hypertension in rodents. However, much of the in vivo data is based on the use of pharmacological ROCK inhibitors (Y27632, fasudil) that are not specific; therefore the in vivo role of ROCK in vascular smooth muscle remodeling remains to be independently determined. There are two ROCK genes, and our hypothesis is that ROCK1plays a distinct role in vascular smooth muscle remodeling and in pulmonary hypertension development, but this has not been studied in a genetic animal model. On this basis, Specific Aim 1 will generate a unique vascular smooth muscle-targeted ROCK1 gene knock-out (KO) mouse strain. Specific Aim 2 will characterize the phenotype of the targeted KO strain. Aim2 will include in vivo studies at baseline and in response to stress such as hypoxia, and studies of cellular and signaling responses of cultured vascular smooth muscle cells derived from the ROCK1KO strain. Overall, the Aims will generate and characterize a novel genetic ROCK animal model, and test the hypothesis in vivo that ROCK1 contributes to remodeling and pulmonary hypertensive disease.