体外鼠脑星形胶质细胞损伤后c-fos蛋白、GFAP及其mRNA的动态表达

DYNAMIC EXPRESSION OF c-fos PROTEIN, GLIAL FIBRILLARY ACIDIC PROTEIN AND ITS mRNA IN INJURED ASTROCYTES IN VITRO

研究ｃ－ｆｏｓ蛋白、ＧＦＡＰ—ｍＲＮＡ和ＧＦＡＰ在鼠脑星形胶质细胞（ａｓｔｒｏｃｙｅ，ＡＳ）损伤后反应性星形胶质化时的动态变化。用ＡＳ原代培养技术建立体外ＡＳ机械损伤模型．并结合应用免疫组织化学和原位杂交方法．结果：（１） ｃ－ｆｏｓ蛋白于损伤后 ４５ ｍｉｎ即有阳性表达，伤后 ２ ｈ消失； （２损伤边缘的 ＡＳ于损伤后 ６ ｈ开始表达 ＧＦＡＰ－ｍＲＮＡ， １ｄ达高峰，３ ｄ则在损伤边缘少数 ＡＳ中可检出 ＧＦＡＰ－ｍＲＮＡ；（３）损伤后 １ｄ，ＧＦＡＰ表达明显增强，胞体肥大，粗大突起伸向损伤区形成反应性星形胶质化。结论：（ｌ） ＡＳ受损后原癌基因 ｃ－ｆｏｓ首先被激活，ｃ－ｆｏｓ蛋白呈－过性的表达，参与调节ＡＳ的激活；（２）ＡＳ损伤后，ＧＦＡＰ－ｍＲＮＡ的转录增加，ＧＦＡＰ表达增强是由于在转录水平上ＧＦＡＰ－ｍＲＮＡ表达增强的结果；（３）反应性星形胶质化是ＡＳ的自身特性，以ＡＳ肥大为主，ＡＳ受损后，原癌基因ｃ－ｆｏｓ的蛋白参与调节ＡＳ激活的确切机制尚待阐明。

PURPOSE To study the dynamic changes of c-fos protein, GFAP-mRNA and GFAP in reactive astrogliosis. METHODS On primary astrocyte culture with mechanical scratch, the markers mentioned above were determined with immunocytochemistry and hybridization. RESULTS (l) c-fos protein presented in the survived astrocytes near the injured area 45 min after damage and disappeared two hours thereafter; (2) GFAP-mRNA was deteactable in astrocytes near the in jury six hours after trauma and reached its peak within twenty-four hours, on the third day few astrocytes near the injured area revealed GFAP-mRNA; (3) enhanced expression of GFAP was observed with hypertrophy of astrocytes which extended widened processes into the injured area one day after scratch and reached its peak on the second day, on the third day the previouly injured area was covered with hypertrophy astrocytes and their processes forming reactive astrogliosis. CONCLUSIONS Oncogene c-fos was rapidly and transiently activated and its proteins might in turn modulate the activation of the injured astrocytes. Enhanced GFAP expression was the result of upregulation of GFAP-mRNA. Reactive astrogliosis was the innate characteristic of astrocytes themselves and the prominent event of astrogliosis was hypertrophy of astrocytes.