摘要目的 研究星形胶质细胞对于营养和氧气剥夺(OGD)的应激反应和Neuregulin-1β1(NRG-1β1)对星形胶质细胞的保护作用.方法(1)通过新生SD大鼠的大脑皮质细胞原代培养,获得高纯度星形胶质细胞.实验组分为对照组、营养和氧气剥夺组以及10、20 ng/ml NRG-1β1保护组.(2)利用免疫荧光化学标记胶质纤维酸性蛋白(GFAP)、S100β和分化抗原簇蛋白44(CD44),了解它们在不同组别实验前后的变化.(3)通过ELISA测定星形胶质细胞OGD前后培养液中肿瘤坏死因子α(TNF-α)和白细胞介素1β(IL-1β)的含量,探究不同组别炎性因子的分泌量.(4)差异显著性分析采用单因素方差分析和t检验,P ＜0.05为差异有统计学意义.结果(1)10和20 ng/ml的NRG-1β1对于OGD处理的星形胶质细胞形态维持的保护作用不明显.(2)GFAP和S100β在星形胶质细胞OGD前后始终存在,表达与分布均无变化,而CD44始终不显色.(3)与OGD组[TNF-α:(14.3 ±0.4)ng/L;IL-1β:(24.8 ±0.1)ng/L]比较,OGD+ 20 ng/ml NRG-1β1组星形胶质细胞TNF-α[(13.0 ±0.5)ng/L]和IL-1β[(23.9 ±0.3)ng/L]的表达量均显著较低(P＜0.05).结论(1)星形胶质细胞在单纯营养剥夺及OGD时都可出现应激反应,历经体积膨胀的代偿阶段和体积缩小的失代偿阶段,但NRG-1β1对OGD细胞形态的保护作用不显著.(2)20 ng/ml NRG-1β1可显著降低肿瘤坏死因子d和白细胞介素1β的分泌,提示NRG-1β1的神经保护机制之一可能是通过降低星形胶质细胞在缺氧缺血损伤中炎性因子肿瘤坏死因子α与白细胞介素1β的分泌.

abstractsObjective To explore the stress responses and protective effects of neuregulin-1β1 (NRG-1β1)on astrocytes after oxygen-glucose deprivation(OGD).Methods Rat cerebral cortical astrocytes from 3-day-old newborn SD rats were propagated.They were divided into control,OGD,10 ng/ml NRG-1β1 and 20 ng/ml NRG-1β1 groups.Immunohistochemical results of GFAP,S100β and CD44 markers were analyzed to observe their changes before and after OGD.Enzyme-linked immunosorbent assay (ELISA)was used to evaluate the secretion of tumor necrosis factor-alpha(TNF-α)and interleukin-1 β(IL-1 β)in different groups before and after OGD.Results Under OGD,NRG-1 β1 showed no protective effects on maintenance of cell morphology.Expression and distribution of GFAP and S100β did not change while there was no expression of CD44 in any group before and after OGD.Secretion of TNF-α and IL-1β significantly decreased in the 20 ng/ml NRG-1 β1 protection group(P ＜ 0.05).Conclusion The morphological changes of astrocytes undergo swelling to shrinking.NRG-1 β1 has no protective effects on maintenance of cell morphology under OGD.And it can significantly decrease the secretion of TNF-α and IL-1β.Thus the reduction of TNF-α and IL-1β may explain the mechanism of protective effects of NRG-1β1 on astrocytes under stress.