Profilin-1在HMGB1/RAGE信号致血栓闭塞性脉管炎大鼠内皮损伤中的作用及机制

Thromboangiitis obliterans (TAO) is a segmental inflammatory disorder that involves primarily the small and medium arteries, veins with thrombosis. In the pathogenesis of TAO, endothelial cells play a key role in initiation and perpetuation of vasculitis lesions through mediating intercellular adhesions between immunocytes as well as inflammatory cells and endothelial cells. Profilin-1, an extensive existing G-actin-binding protein, play a major role in endothelial injury. Our previous experiments show that Profilin-1 involved in the development of TAO, and HMGB1/RAGE pathway is an important upstream signal induced endothelial injury in TAO. Both of them share common downstream signaling pathways. We hypothesize that HMGB1/RAGE regulate downstream signaling through Profilin-1 to induce endothelial injury. To prove the hypothesis, animal models and in vitro model systems will be used in the current study. First we investigate the activation status of Profilin-1 and HMGB1/RAGE signaling pathway. The effects of Profilin-1 on the activation of signaling factors in HMGB1/RAGE pathway will be explored by intervening Profilin-1 and RAGE. Our findings will elucidated the underlying mechanisms of TAO and provide a theoretical basis for effective treatment.

血栓闭塞性脉管炎（TAO）是一种以中小动静脉节段性病变并管腔内血栓形成为特征的炎性疾病，在其发病机制中，内皮细胞发挥“始动性”和“持续性”作用，主要方式为通过介导免疫细胞和炎细胞黏附内皮细胞导致内皮损伤参与血管炎性病变。Profilin-1是一种体内广泛存在的G-肌动蛋白结合蛋白，是内皮损伤过程中的重要因子。我们的前期实验表明Profilin-1参与了TAO发展过程；并且发现HMGB1/RAGE途径是介导TAO内皮损伤的重要上游机制，两者存在共同的下游信号通路。本课题提出HMGB1/RAGE通过Profilin-1调控下游信号，造成内皮损伤的假说。从动物模型和细胞两方面，研究Profilin-1与 HMGB1/RAGE 信号途径中各因子的表达与激活的关系。进一步通过干预 Profilin-1 和RAGE观察对上述通路和病情进展的影响。本课题为明确TAO的发病机制和寻找有效治疗措施提供理论。

血栓闭塞性脉管炎（TAO）是一种以中小动静脉节段性病变并管腔内血栓形成为特征的炎性疾病，其致残率高，一直缺乏有效的治疗手段，目前其发病机制尚不明确，但是内皮损伤导致的血管炎性病变是主要致病因素。在前期实验中我们发现Profilin-1参与了TAO发展过程；并且发现HMGB1/RAGE途径是介导TAO内皮损伤的重要上游机制，两者存在共同的下游信号通路。本课题我们在动物模型和细胞两方面，通过分别和联合干预HMGB1/RAGE和（或）Profilin-1（包括过表达和抑制的方法），利用大体病理分级、血栓面积检测、ELISA、免疫共聚焦、流式细胞学、线粒体膜电位、ROS检测、WB、PCR等技术手段。发现Profilin-1加速了TAO病情进展，导致肢体缺血加重；HMGB1通过与其受体RAGE结合调控下游Profilin-1促进炎性因子释放， NO释放减少、内皮细胞释放ET-1、vWF增多，细胞迁移增快，活性氧水平增高、线粒体膜电位紊乱，内皮稳态被打破，内皮产生损伤，其防御功能降低，从而导致疾病进展，而抑制以上不利因素，能够减少内皮损伤，减缓病情的发展。这为明确TAO的发病机制和寻找有效治疗措施提供理论基础。