Gene expression profiling of Tsp1 deficient rat aortic smooth muscle cells with mechanical stretch

The extracellular matrix (ECM) initiates mechanical cues and transduces intracellular signaling through matrix-cell interactions. The nature of cues and how they coordinate with a mechanical microenvironment are not fully understood. We identified the matricellular protein,thrombospondin-1 (Tsp1, also called Thbs1),as a mediator of matrix mechanotransduction that acts via integrin αvβ1 to establish focal adhesions and promotes nuclear shuttling of Yes-associated protein (YAP) in response to cyclic stretch. Thbs1-mediatedYAP activation depends on the small GTPase Rap2 and Hippo pathway, and is not influenced by altered actin fibers. Hence, to gain insight into the molecular mechanisms underlying the Tsp1-mediated matrix mechanotransduction, we performed a comprehensive analysis of gene expression changes in Tsp1deficiant SMCs with mechanical stretch using RNA sequencing (RNA-Seq).细胞外基质（extracellular matrix, ECM）可启动机械信号，并通过基质-细胞相互作用转导细胞内信号通路。目前，此类信号的本质及其与机械微环境的协同调控机制尚未完全阐明。我们鉴定出基质细胞蛋白（matricellular protein）血小板反应蛋白-1（thrombospondin-1, Tsp1，亦称Thbs1）作为基质机械转导的介质，其可通过整合素αvβ1（integrin αvβ1）介导黏着斑的形成，并在周期性牵张刺激下促进Yes相关蛋白（Yes-associated protein, YAP）的核转位。Thbs1介导的YAP激活依赖于小GTP酶Rap2以及Hippo信号通路，且不受肌动蛋白纤维改变的影响。为深入解析Tsp1介导的基质机械转导的分子机制，我们采用RNA测序（RNA sequencing, RNA-Seq）技术，对周期性牵张刺激下的Tsp1缺陷型平滑肌细胞（smooth muscle cells, SMCs）的基因表达变化进行了全面分析。