星形神经胶质细胞对PC12神经元突起生长发育的影响

背景星形细胞对神经元有提供营养、支持及调节突触活性作用,但它对神经元发育的影响还尚不清楚.目的探讨体外培养的SpragueDawley大鼠大脑皮质星形细胞对PC12神经元突起生长发育的作用.设计完全随机设计,对照实验研究.方法以培养的星形细胞与PC12神经元按不同细胞数目比例(501～11)共同培养,并用其制备的条件培养液培养PG12细胞.主要观察指标用快速灵敏的MTT'比色法测定PC12神经元的细胞活力,用光学相差显微镜观察PC12细胞形态学变化.结果①星形细胞条件培养液可增强PG12细胞活力(MTT测定的A值由0.255±0.012提高到0.510±0.036,P＜0.001),却不能促使PC12神经元突起的生出.②当将星形细胞与PC12细胞按301～11的比例共同培养时,既可提高PC12细胞折光性和光晕又可促使其突起的生长;但按501～401的比例共同培养时,只观察到提高PC12细胞折光性和光晕,而无促使其突起生长发育的作用.结论PC12神经元细胞活力的提高与星形细胞分泌到条件培养液中的可溶性因子有关,而PC12神经元突起生长发育可能是和与星形细胞的直接接触以及二者的细胞数目比有关.

Effects of cultured astrocytes from rat cerebral cortex onthe neurite development of PC12 cells

BACKGROUND: Although astrocytes are kown to provide structural andtrophic support to neurons and modulate synaptic activity, their role is farfrom being completely understood.OBJECTIVE: To investigate effects of cultured astrocytes fromSprague-Dawley rat cerebral cortex on the neurite development of PC12 cellsderived from rat pheochromocytoma.DESIGN: Completely randomized controlled trial.METHODS: PC12 cells were co-cultured with astrocyte according to dif-ferent astrocytes/neurons ratio(50: 1 -1: 1), or cultured with serum-freeconditioned medium of astrocytes (ACM).MAIN OUTCOME MEASURES: The vitality of PC12 cells was measuredby sensitive MTT method and their morphologic features were observed byOlympus light microscope.RFSULTS: When PC12 cells were cultured with ACM, compared with thecontrol group, the vitality of PC12 cells was increased significantly(0. 255 ± 0. 012 vs 0. 510 ± 0. 036, P ＜ 0. 001 ) , but the neurite growthwas not obvious in the experimental group. When PC12 cells wereco-cultured with astrocyte in the ratio of 30:1 - 1: 1, not only was thevitality of PC12 cells enhanced, but also the neurite-outgrowth of PC12was observed. However, when PC12 cells were co-cultured with astrocyte inproportion of 50:10 -40: 1, the vitality of PC12 cells was also enhanced,but the neurite-outgrowth of PC12 was not found.CONCLUSION: This study suggested enhancement of PC12 cell-vitality wasmediated by soluble factors produced by astrocytes, while activity of theneurite-promoting was associated with cell-cell contact and with the ratio oftwo cells.