接头蛋白PINCH介导的信号通路在血管形成和维护中的功能

The adapter protein PINCH1 and PINCH2 mediate bidirectional integrin signaling and play important roles in multiple cellular processes and organogenesis. But their role in the vasculature remains unknown. We generated several endothelial (ECs) and vascular smooth muscle cell (VSMCs) specific PINCH mutant mouse lines using Tie2-Cre and Pdgfrb-Cre. We found that double deletion of PINCH1 and PINCH2 in ECs led to decreased endothelial tube formation and reduced number of ECs. In mice with PINCH1 being deleted in ECs, initial formation of microvascular plexus appeared to be normal, but their subsequent remodeling and maturation were defective, suggesting a failure for ECs to recruit and interact with perivascular cells to maintain vascular structures. Deletion of PINCH in VSMCs resulted in significant vessel enlargement in multiple organs, including brain and heart, and hemorrhage. Increased wall thickness in some medium- to large-sized arteries was observed. We hypothesized that PINCH may play important roles in endothelial proliferation, differentiation and migration to form primitive endothelial tubes. High dose of PINCH expression is required for the recruitment of smooth muscle cells and pericytes to generate mature and functional vessels. PINCH expression in VSMCs is required for their proliferation and differentiation. To test these, our Specific Aims are: 1) To examine the role of PINCH in endothelial proliferation, differentiation, survival and migration, and ability to form endothelial tubes in vivo and in vitro; 2) To examine the role of PINCH in mediating endothelial and mural cell interaction and in vessel wall assembly and maturation; 3) Using candidate gene approach, RNA-seq and phospho-antibody array analysis to investigate molecular mechanisms of PINCH in vascular development. Results of proposed studies will provide novel molecular insights into vessel formation, and will enhance our understanding of the pathology of human disorders associated with vascular malformation.

接头蛋白PINCH是整合素信号通路的核心蛋白，在器官发育和维护中起关键作用。为研究其在血管发育中的作用，我们建立了血管内皮（ECs）和平滑肌（VSMCs）特异性PINCH1和PINCH2敲除的小鼠模型。我们发现，在ECs中不同程度敲除PINCH导致血管网的形成和成熟障碍。在VSMCs中敲除PINCH导致血管扩张和VSMCs高度增殖。推测：PINCH介导了血管细胞和信号通路的相互作用，在血管形成和稳态维护中起重要作用。本研究将阐明：PINCH在ECs和VSMCs的增殖，分化，迁移和存活中的作用，及PINCH和ILK在VSMCs的增殖和分化中的独特调控机制；探讨PINCH介导的细胞相互作用和信号通路的整合机制，及其在血管形成和成熟中的作用；通过磷酸化蛋白芯片和转录组学分析，探讨PINCH的下游信号通路及筛选靶点。本研究将加深我们对人类血管疾病发生机制的理解，为探索新的预防和治疗方法提供基础。

PINCH是整合素信号通路的接头蛋白，在器官发育和维护中起关键作用。为研究其在血管发育中的作用和机制，我们建立了血管内皮（ECs）和平滑肌（VSMCs）特异性PINCH1和PINCH2敲除的小鼠模型。我们的研究发现，在ECs中不同程度敲除PINCH导致血管网的形成和成熟障碍；在VSMCs中敲除PINCH导致血管扩张和VSMCs高度增殖。揭示了PINCH介导了血管细胞和信号通路的相互作用，其在血管形成和稳态维护中起重要作用。本研究阐明了PINCH在ECs和VSMCs的增殖，分化，迁移和存活中的作用，及PINCH和ILK在VSMCs的增殖和分化中的独特调控机制；PINCH介导的细胞相互作用和信号通路的整合机制，及其在血管形成和成熟中的作用。磷酸化蛋白芯片和转录组学分析结果显示PINCH的下游信号通路和相关靶点。本研究加深了对人类血管疾病发生机制的理解，为探索新的预防和治疗方法奠定理论基础。