创伤性脑损伤(TBI)后的微血栓形成是导致继发性脑缺血的重要因素。NF-κB活化能够打破纤凝平衡，促进微血栓形成。课题组前期发现，PTEN参与了脑缺血后NF-κB的活化；抑制PTEN可以减少TBI后神经元凋亡，降低血脑屏障通透性，但其对TBI后微血栓形成的作用和机理尚未阐明。我们推测，颅脑创伤后，PTEN的泛素化修饰能够通过调控NF-κB信号通路，参与挫伤灶及周边组织微血栓形成。为此，本项目拟通过建立脑微血管内皮细胞牵张损伤模型和小鼠皮层控制损伤模型，分析PTEN泛素化和NF-κB的活化情况；进一步构建泛素连接酶CHIP过表达或siRNA的慢病毒载体，通过细胞转染和侧脑室注射，观察PTEN泛素化修饰对NF-κB活性的影响，同时探讨上述变化对TBI后脑微血管内皮细胞功能及损伤区微循环的影响，进而阐明其在创伤后脑组织微血栓形成的作用及机制，为寻找TBI后缺血性脑损伤防治方法提供实验依据。

The microthrombosis formation after traumatic brain injury (TBI) is an important factor leading to secondary ischemic brain injury. NF-κB activation can break the dynamic balance between coagulation and fibrinolysis to promote microthrombosis formation. We found that PTEN was involved in the activation of NF-κB after cerebral ischemia, and the inhibition of PTEN could reduce the apoptosis of neurons and the permeability of blood brain barrier after TBI. However, the impact of PTEN on the TBI induced microthrombosis has not been elucidated. We speculate that the ubiquitination of PTEN plays an important role in microthrombosis formation after TBI via the regulation of NF-κB signal pathway. To verify this hypothesis, we will observe the PTEN ubiquitination and NF-κB activation after TBI in the brain microvascular endothelial cells (BMVEC) stretch injury model and mice cortex controlled injury model. Furthermore, the overexpression or RNA interference of E3 ligase CHIP via lentivirus transfection was applied to regulate PTEN ubiquitination and expression, in order to evaluate the impact of PTEN ubiquitin modification on NF-κB activity, the function of BMVEC and the microcirculation after TBI. Thus, this program is expected to clarify the role and mechanism of PTEN ubiquitination in TBI induced microthrombosis formation and provide experimental basis for the treatment of ischemic brain injury after TBI.