中文摘要：

目的探讨不同刺激对N9小胶质细胞炎性细胞因子分泌及存活的影响。方法体外培养N9小胶质细胞,分为空白对照组（Control组）、M1型刺激组（LPS＋IFN-γ组）、M2型刺激组（IL-4组）。刺激24 h后,通过实时荧光定量PCR及ELISA检测N9小胶质细胞在极化状态下细胞因子的表达;同时体外培养N9小胶质细胞,分为Control组、LPS组、IFN-γ组、LPS＋IFN-γ组及IL-4组,通过Hoechst-PI染色的方法检测不同因子对细胞死亡的影响,并用Western blot检测各组Caspase-3的表达。结果 LPS＋IFN-γ组N9细胞促炎因子表达明显高于Control组及IL-4组（P〈0.01）,IL-4组N9细胞抑炎因子的表达明显高于Control组及LPS＋IFN-γ组（P〈0.01）。在细胞存活方面,IFN-γ组及LPS＋IFN-γ组N9细胞的死亡数及Caspase-3的表达明显高于Control组、LPS组、IL-4组（P〈0.05,P〈0.01）。结论 N9细胞可发生极化,在不同极化状态表达不同的炎性因子;IFN-γ可影响N9细胞的存活,其可能是通过Caspase-3而导致细胞死亡。

英文摘要：

Objective To investigate inflammatory cytokines expression and survival of N9 microglia after different stimulations. Methods In vitro,cultured N9 microglias were divided into a control group,a LPS ＋ IFN-γ stimulation group（ M1） and an IL-4 stimulation group（ M2）. Total RNA were extracted and inflammatory cytokine mRNA were detected through Q-RT-PCR and total culture media were collected to detect the concentration of inflammatory cytokines through ELISA,24 h after stimulation. N9 microglias were divided into a control group,a LPS group,an IFN-γ group,a LPS ＋ IFN-γ group,and an IL-4 group to study the effects of the cytokines on N9 microglia survival. The survival rates of each group were detected through Hoechst-PI staining. The expression of caspase-3 was detected by Western blotting. Results In the aspect of inflammatory cytokines secretion,the cells in group M1 expressed more pro-inflammatory cytokines than those in the control group and group M2（P〈0. 01）. The cells in group M2 expressed more anti-inflammatory cytokines than those in the other 2 groups（P〈0. 01）. In the aspect of cell survival,we found the cells in the IFN-γ and LPS ＋ IFN-γ groups had lower survival rates and higher caspase-3 expression than those in other groups（ P〈0. 05,P〈0. 01）. Conclusion N9 microglia can be polarized like macrophages and express different inflammatory cytokines after different stimulations. IFN-γ may affect the survival of N9 microglia though regulating Caspase-3 expression.