尼古丁对脂多糖诱导的小胶质细胞激活及活化后细胞死亡的影响

目的 观察尼古丁对脂多糖(LPS)诱导的小胶质细胞激活及活化后细胞死亡的影响. 方法 建立慢性尼古丁暴露的小鼠动物模型,腹腔注射LPS诱导小胶质细胞激活,应用免疫组织化学方法 观察皮质、海马、黑质CD-11b阳性小胶质细胞表达的变化;BV2细胞(小鼠小胶质瘤细胞系)传代培养,运用CCK-8试剂盒检测细胞活性,一氧化氮检测试剂盒检测一氧化氮(NO)释放情况,RT-PCR分析诱导型一氧化氮合酶(iNOS)、肿瘤坏死因子(TNF-α)、白细胞介素1(IL-1β)、白细胞介素6(IL-6)、环氧化酶-2(COX-2)、干扰素调节因子1(IRF-1)、Caspase-11 mRNA的表达,免疫印迹法分析P-I-κB、Caspase-3的表达变化. 结果 尼古丁抑制LPS诱导的皮质、海马、黑质CD-11b阳性小胶质细胞的表达;尼古丁抑制LPS刺激引起的BV2细胞的死亡,NO的释放,iNOS、TNF-α、IL-1β、IL-6、COX-2、IRF-1、Caspase-11 mRNA的表达,P-I-κB、Caspase-3蛋白的表达. 结论 尼古丁可以抑制LPS诱导的小胶质细胞活化及激活诱导的细胞死亡(AICD),对脑内炎症反应具有神经保护作用.

Effect of nicotine on the activation and resultant death of microglia induced by lipopolysaccharid

Objective To observe the effect of nicotine(NIC) on the activation and resultant death of microglia induced by LPS. Methods The animal model that exposed to chronic nicotine treatment was established and LPS was injected intraperitoneally to induce the activation of microglia. Furthermore, the CD11b-positive microglia in cerebral cortex, hippocampal and substantia ngra were observed through immunohistochemical staining. BV2 cells(Microglial cell line of mouse) were subcultured, simultaneously the following kits were used including CCK-8 kit assay for cell activity, Nitric oxide assay kit assay for NO release, RT-PCR assay for the iNOS,TNF-α,IL-1β,IL-6,COX-2,IRF-1,Caspase-11 mRNA expression, Western blotting assay for the protein expression of P-I-κB and Caspase-3. Results Nicotine suppressed the CD11b-positive microglia expression in cerebral cortex,hippocampal and substantia ngra induced by LPS;Nicotine inhibited the activation-induced cell death (AICD), attenuated NO release, reduced iNOS,TNF-α,IL-1β,IL-6,COX-2,IRF-1,Caspase-11 mRNA expression, decreased the protein expression including P-I-κB and Caspase-3 of BV2 cells. Conclusion Nicotine pretreatment can suppress the activation and resultant death of microglial cells induced by LPS, which suggests that nicotine may play a neuroprotective role on inflammatory reaction of brain.;