中文摘要：

目的：探讨脂多糖对大鼠大脑皮层星形胶质细胞（AS）增殖的影响、ephrin-A3在其中的表达变化及其可能机制。方法：提取新生大鼠大脑皮层AS并纯化培养,随机分为对照组,脂多糖（10 mg/L）干预30 min组、6 h组、24 h组、48 h组和72 h组,采用倒置相差显微镜观察AS形态学变化,MTT法检测细胞活性,AO/EB荧光染色检测细胞凋亡和坏死情况,免疫荧光测定不同时点ephrin-A3和胶质细胞原纤维酸性蛋白（glial fibrillary acidicprotein,GFAP）的表达变化,ELISA法测定细胞培养液内炎症因子肿瘤坏死因子α（TNF-α）和白细胞介素6（IL-6）的变化。结果：在脂多糖作用的不同时点,与对照组相比,作用24 h、48 h、72 h的细胞活性显著升高,凋亡率显著下降,ephrin-A3和GFAP表达显著升高,培养液内TNF-α和IL-6显著升高。结论：脂多糖可以促进大鼠大脑皮层AS增殖。Ephrin-A3在脂多糖诱导的AS增殖中的表达增高,其表达增加可能与炎症因子有关。

英文摘要：

AIM： To explore the effects of ephrin-A3 expression on the proliferation of astrocytes induced by lipopolysaccharide（LPS）.METHODS： Astrocytes from cerebral cortex of newborn rats were cultured and purified.The cells were exposed to LPS at the concentration of 10 mg/L and divided into 6 groups at random： control group（without LPS） and the groups of exposure to LPS for 30 min,6 h,24 h,48 h and 72 h.The morphological changes of the astrocytes were observed under inverted phase-contrast microscope.The survival rate and apoptotic rate of astrocytes were measured by MTT method and AO/EB staining,respectively.The expression of ephrin-A3 and glial fibrillary acidic protein（GFAP） was measured by fluorescein staining with CY3.The changes of the inflammatory factors TNF-α and IL-6 in the culture supernatant were detected by ELISA.RESULTS： Compared with control group,the survival rates were notably increased,the apoptotic rates were notably decreased,the expression of ephrin-A3 and GFAP was significantly up-regulated and the inflammatory cytokines were significantly increased in the cells exposed to LPS at the concentration of 10 mg/L for 24 h,48 h and 72 h.CONCLUSION： LPS promotes the proliferation of astrocytes.The expression of ephrin-A3 increases during the proliferation of astrocytes induced by LPS in rats.The mechanism may be related to inflammatory stimulation by cytokines.