CLCN7(R286W)介导TGF-β信号通路在石骨症中的作用与机制

石骨症是一种破骨细胞异常导致的骨质硬化罕见遗传病，该病与CLCN7等破骨细胞发育相关基因突变有关，但其确切病理机制未明。我们前期发现CLCN7(R286W)是石骨症家系致病基因突变，并利用患者体细胞建立了疾病特异诱导多能干细胞(ADO2-iPSCs)。最近研究发现CLCN7、CTSK以及TGF-β信号通路在骨骼及骨骼外组织细胞发育中具有重要调控作用，我们推测：CLCN7(R286W)介导TGF-β信号通路可能调控石骨症患者骨代谢异常。本研究拟以ADO2-iPSCs为疾病细胞模型，以CRISPR-Cas9修复CLCN7(R286W)建立自身对照iPSCs，诱导其向破骨细胞分化，以体外、体内实验评价CLCN7(R286W)、CTSK以及TGF-β信号通路关键信号分子调控破骨细胞骨吸收功能的作用，以期揭示石骨症骨质硬化机制，为石骨症治疗药物研发及人类常见骨代谢异常疾病研究提供新的依据。

Osteopetrosis is a rare genetic disorder characterized by a generalized skeletal sclerosis. It is caused by mutations in CLCN7 and the genes associated with osteoclast differentiation. However, the exact pathogenesis of osteopetrosis is not clear yet. In our previous study, we have identified CLCN7(R286W) as mutation in an osteopetrosis family, and generated a cell line of disease specific induced pluripotent stem cells (ADO2-iPSCs). Recent studies indicate that the regulation roles of CLCN7, CTSK and TGF-β signal pathway are very important in the development of bone and exoskeleton cells. We hypothesize that the role of CLCN7(R286W) in TGF-β signaling pathway is important in abnormal bone metabolism of osteopetrosis patients. In this study, we plan to use the ADO2-iPSCs as a cell model of the disease, and establish a cell line of self-control iPSCs by the application of CRISPR-Cas9 to edit CLCN7 (R286W). Then the role of CLCN7 (R286W) in the TGF-β signaling pathway in the resorption of osteoclast will be studied in vivo and in vitro. It may reveal the mechanism of osteosclerosis in the patients with osteopetrosis.And new evidences may be provided for the therapeutic drug development of osteopetrosis, and the study of human common diseases associated with abnormal bone metabolism.