Blocking epidermal growth factor receptor attenuates reactive astrogliosis through inhibiting cell cycle progression and protects against ischemic brain injury in rats
Blocking epidermal growth factor receptor attenuates reactive astrogliosis through inhibiting cell cycle progression and protects against ischemic brain injury in rats
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阻断表皮生长因子受体通过抑制细胞周期进程来减轻反应性星形胶质细胞增生，并防止大鼠缺血性脑损伤
DOI：
10.1111/j.1471-4159.2011.07446.x
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发表时间：
2011-11-01
影响因子：
4.7
通讯作者：
Tian, Dai-Shi
中科院分区：
文献类型：
--
作者：
Yang, Qin;Wang, En-Yin;Tian, Dai-Shi
过度的星形胶质细胞增生是中枢神经系统疾病轴突再生的主要障碍。克服这种反应性星形胶质细胞的抑制屏障可能对CNS修复至关重要。表皮生长因子受体（EGFR）的上调和激活已被证明可以触发静止的星形胶质细胞转化为反应性星形胶质细胞，以响应多种神经损伤。在这项研究中，我们研究了EGFR阻断在培养的星形胶质细胞暴露于氧-葡萄糖剥夺/复氧（OGD/R）和大鼠大脑中动脉闭塞（MCAO）模型中的作用。采用原代培养的星形胶质细胞建立OGD/R模型，成年雄性Sprague-Dawley大鼠建立MCAO模型。流式细胞仪分析体外培养星形胶质细胞的细胞周期进程。通过免疫染色和蛋白质印迹分析评估体外和体内磷酸化表皮生长因子受体（p-EGFR）、胶质纤维酸性蛋白（GFAP）和细胞增殖相关分子的表达。采用末端脱氧核苷酸转移酶缺口末端标记法（TUNEL）检测脑缺血后神经细胞凋亡。在大鼠MCAO模型中评估缺血后的神经系统评分和梗死体积。星形胶质细胞在OGD/R和MCAO后被激活，并伴有EGFR磷酸化。EGFR阻断显著降低了p-EGFR的表达，抑制了星形胶质细胞的细胞周期进程，并在体外和体内减少了反应性星形胶质细胞增生。EGFR抑制还减少了梗死体积，改善了MCAO后大鼠的神经系统评分。我们的研究结果表明，阻断EGFR通路可能通过抑制细胞周期进程减轻反应性星形胶质细胞增生，保护大鼠缺血性脑损伤。
Excessive astrogliosis is a major impediment to axonal regeneration in CNS disorders. Overcoming this inhibitory barrier of reactive astrocytes might be crucial for CNS repair. Up-regulation and activation of epidermal growth factor receptor (EGFR) has been shown to trigger quiescent astrocytes into reactive astrocytes in response to several neural injuries. In this study, we investigated the effects of EGFR blockade in cultured astrocytes exposure to oxygen-glucose deprivation/reoxygenation (OGD/R) and in the rat middle cerebral artery occlusion (MCAO) model. Astrocytes in primary culture were used for OGD/R model and adult male Sprague-Dawley rats were used for MCAO model. Cell cycle progression of astrocytes in vitro was studied by flow cytometric analysis. Expression of phosphorylated epidermal growth factor receptor (p-EGFR), glial fibrillary acidic protein (GFAP), and cell proliferation-related molecules in vitro and in vivo were evaluated by immunostaining and western blot analysis. Neuronal apoptosis after MCAO was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Neurologic scores and infarct volumes post-ischemia were assessed in the rat MCAO model. Astrocytes became activated in the cultured astrocytes exposure to OGD/R and in the rat brain after MCAO, accompanied with phosphorylation of EGFR. EGFR blockade significantly decreased expression of p-EGFR, inhibited cell cycle progression of astrocytes, and reduced reactive astrogliosis in vitro and in vivo. EGFR inhibition also reduced infarct volumes and improved neurologic scores of rats after MCAO. Our findings indicated that blocking EGFR pathway might attenuate reactive astrogliosis through inhibiting cell cycle progression and protect against ischemic brain injury in rats.