星形胶质细胞钙调蛋白在损伤后胶质瘢痕形成中的作用

Effect of calmodulin on the formation of glial scar after the astrocyte injury

目的:探讨钙调蛋白对星形胶质细胞损伤后增生及胶质瘢痕形成的影响。方法:体外纯化培养星形胶质细胞,机械划痕法构建星形胶质细胞损伤模型,动态观察星形胶质细胞损伤前后钙离子浓度的变化,以及损伤后应用钙调蛋白抑制剂三氟拉嗪(Trifluoperazine dihydrochloride,TFP)处理,星形胶质细胞增生的主要标志物GFAP表达的变化。采用激光共聚焦观察细胞内游离钙离子浓度动态变化,免疫组织化学染色方法检测星形胶质细胞胶质纤维酸性蛋白(Glia fibrillary acidic protein,GFAP)表达量的变化。结果:星形胶质细胞损伤后细胞内钙离子浓度迅速上升,2min后明显下降至接近基础水平。星形胶质细胞损伤后钙调蛋白抑制剂能够抑制星形胶质细胞GFAP蛋白表达量的增加。结论:星形胶质细胞损伤后钙离子浓度明显变化,激活细胞内钙离子信号传导并参与星形胶质细胞损伤后的增生反应,而钙调蛋白抑制剂三氟拉嗪对星形胶质细胞损伤后的增生反应有显著的抑制作用。

Objective： To study the effect of calmodulin on reactive astrocytosis and formation of glial scar after astrocytes are injured. Methods： Astrocytes were prepared from newborn rat cerebral cortex and evaluated the purity by immunostaining of glial fibrillary acidic protein （ GFAP ）. The astrocyes injury model was made by means of surgical blade scraping. We observed the concentration of intracellular free calcium before and after injury in dynamic state .Then injured astrocytes were divided into two groups. The intervention group was added with suppressive agent of calmodulin-trifluoperazin dihydrochloride （TFP）after injury; the control group wae added into nothing. At different times after injury, we performed immunocytochemical staining for glial fibrillary acidic protein （GFAP）on each group and immunocytochemical staining photographs were analyzed by image analysis system, obtaining average optical densities. Results： Concentration of the tracellular free calcium increased quickly 2 minutes after astrocytes were injured. The immonocytochemical staining results indicated the control group and the intervention group had statistical significance. Conclusion： After astrocytes were injured the intracellular free calcium concentration obviously incredsed, activated the intracellular Ca^2＋ signal pathway and participatal in the proliferation. TFP can obviously inhibit this proliferation reaction after the astrocytes are injured.