Smurf1对BMP7介导的晶状体上皮细胞生物学行为的调控作用

晶状体上皮细胞（LECs）增殖、上皮间质转分化（EMT）是后发性白内障（PCO）的病理基础。转化生长因子（TGF-β）是导致EMT最重要的细胞因子。我们发现TGF-β超家族成员骨形成蛋白7（BMP7）和泛素蛋白酶体途径（UPP）抑制剂MG132都能抑制TGF-β的生物学作用，并且MG132可以下调E3泛素连接酶Smurf1激活BMP途径，由此我们提出：UPP通路中的Smurf1可能是TGF-β/BMP信号通路的关键调节因子，选择性降解Smad蛋白，在翻译后水平调控LECs的增殖和EMT。本项目拟：1）应用CRISPRI/Cas9及腺相关病毒载体调控Smurf1及BMP7的表达水平，观察对LECs生物学行为的影响2）蛋白芯片技术分析Smurf1调控TGF-β/BMP信号通路中的关键信号分子3）构建外伤诱导小鼠前囊下白内障模型，从体内实验进一步验证，以期为后发性白内障的预防和治疗提供新的靶点。

The pathological mechanism of posterior capsule opacification (PCO) includes proliferation and epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs). Transforming growth factor (TGF-β) is the most significant cytokine that induces the EMT. It was indicated in our previous study that bone morphogenetic protein-7 (BMP-7), a member of TGF-β superfamily, can inhibit the EMT induced by TGF-β and the proliferation of LECs probably through activating Smad1/5/8. Ubiquitin-proteasome pathway (UPP) can regulate Smurf1, one of the ubiquitin-protein ligating enzymes (E3) which can selectively degrade Smad1/5, and inactivate the BMP signaling pathway, so as to regulate the proliferation, migration and EMT of LECs at the post-translation level. We hypothesize that Smurf1 may be a key regulator of UPP pathway to regulate the activity of TGF-β/BMP signaling pathways. We intend to study the interaction of Smurf1 and BMP-7 signaling pathway and their influences on the biological behavior of mouse LECs by using CRISPR/Cas9 gene editing technique and rAAV. We will also analyze the key signaling molecules in the TGF-β/BMP signaling pathway regulated by Smurf1 though bioinformatics and protein microarray technique. Moreover, we will establish injury-induced anterior subcapsular cataract models of mouse and observe the influences of Smurf1 on cataract formation histologically and pathologically, as well as the influences on the activity of TGF-β/BMP signaling pathway. The purpose of this project is to explore a new target in the prevention and treatment of posterior capsule opacification.