蛋白酪氨酸磷酸酶SHP-2调节星形胶质细胞活化对脑梗塞胶质疤痕形成的影响及其分子机制

In cerebral ischemia, increased reactive astrogliosis and scar formation impede neurite growth and regeneration during recovery state. Regulation of reactive astrogliosis and scar formation has been proposed to be a therapeutical strategy for treating cerebral ischemia. SHP-2, a protein tyrosine phosphatase (PTP), regulates signaling pathways, manipulating variety of cell activities. Our preliminary study shows that SHP-2 expressed in reactive astrocytes in the ischemic penumbra in mice. In addition, inhibition of SHP-2 activity promotes primary astrocyte proliferation at least partially mediated by ERK1/2 and p38 activation. These observations intrigue us to further investigate role of SHP-2 in regulation of reactive astrogliosis and scar formation during ischemia and recovery, and its molecular mechanisms. For these purposes, we will be generating an inducible conditional astrocytic SHP-2 knockout transgenic mouse line to investigate the effects of SHP-2 knockout on ischemia-induced reactive astrogliosis and scar formation, and its role in regulation of ischemic damage and recovery. Furthermore, we will study molecular mechanisms of SHP-2 in regulation of reactive astrogliosis，particularly on MAPKs, Akt/mTOR, and STAT3 signaling pathways in primary astrocytes culture. We believe this study could contribute to unfold the mechanisms of reactive astrogliosis, and may provide a potential target for intervention in the treatment of cerebral ischemia.

在脑梗塞中，损伤半影区的星形胶质发生活化，形成的胶质疤痕是阻止损伤扩散和阻碍愈后的关键病变。研究星形胶质细胞活化的机制以及脑梗塞模型中胶质疤痕形成的调控对于防治疾病具有重要意义。蛋白酪氨酸磷酸酶SHP-2可调节细胞内蛋白磷酸化平衡。我们最新研究发现SHP-2在小鼠脑梗塞半影区活化星形胶质细胞中过表达；在原代培养星形胶质细胞中抑制SHP-2可诱导ERK1/2以及p38磷酸化，导致星形胶质细胞活化增殖。因此我们推测SHP-2可调控星形胶质细胞活化和胶质疤痕形成。在本项目中，我们将构建诱导型星形胶质细胞特异性SHP-2敲除小鼠，采用整体试验验证SHP-2对小鼠脑梗塞损伤后星形胶质细胞活化、胶质疤痕形成以及愈后各项指标的调控；并采用离体试验探索SHP-2在星形胶质细胞中对于下游信号通路的调节作用，解析SHP-2在脑梗塞胶质疤痕形成过程中调控星形胶质细胞活化的分子机制，研究脑梗塞损伤防治的新药靶点。

本项目建立了体外星形胶质细胞活化模型，检测了Shp2及其下游蛋白STAT3在星形胶质细胞活化过程中的表达调控，并利用Shp2特异性抑制剂和基因沉默技术，研究SHP-2如何调控星形胶质细胞活化，从而初步完成了探索Shp2如何调控星形胶质细胞活化及其分子机制的研究目标。项目进一步培育并成功鉴定基于GFAP启动子的条件性Shp2基因敲除小鼠，观察并研究Shp2条件性敲除对幼鼠生存、生长及躯体感觉运动功能发育的影响，对Shp2条件性敲除对星形胶质细胞、神经元数量分布的影响及对幼鼠大脑皮质、小脑及脑干组织结构的影响并初步探讨相关分子机制进行了研究，从而初步阐明了Shp2在小鼠神经干细胞分化、星形胶质细胞数量及中枢神经系统总体发育过程中的功能。.已发表SCI论文1篇，发表博士毕业论文1篇，培养毕业博士生1名，培养在读博士生2名，在国际学术会议做特邀报告1次，在国内学术会议做特邀报告1次，举办国际学术会议1次，举办国内学术会议1次。获中国医师协会神经外科分会颁发的学术成就奖1项