神经肽Y对大鼠皮质神经元凋亡的调节作用研究

Regulation of neuropeptide Y on the apotosis of cerebral cortical neurons in rats

目的探讨神经肽Y(NPY)对大鼠神经小胶质细胞生成白细胞介素-1β(IL-1β)的影响以及对神经元凋亡的调节作用。方法培养原代大鼠皮质小胶质细胞,分为5组,对照组以无血清培养基孵育,LPS组以含脂多糖(LPS)的无血清培养基孵育,NPY+LPS组先后予含NPY和LPS的无血清培养基孵育,NPY组以含NPY的无血清培养基孵育,BIBP3226+NPY+LPS组先后用含BIBP3226、NPY和LPS的无血清培养基孵育。孵育6 h后,ELISA方法检测各组培养液中IL-1β蛋白含量,RT-PCR方法检测各组小胶质细胞中IL-1βmRNA表达水平。然后用各组培养液分别孵育原代培养的大鼠皮质神经元,采用Hoechst33258染色鉴定神经元凋亡情况。结果 LPS组培养液中IL-1β蛋白含量及小胶质细胞中IL-1βmRNA表达水平均显著高于对照组(P均<0.05),神经元凋亡率明显高于对照组(P<0.05)。NPY+LPS组培养液中IL-1β蛋白含量和小胶质细胞中IL-1βmRNA表达水平均明显低于LPS组(P均<0.05),神经元凋亡率明显低于LPS组(P<0.05)。BIBP3226+NPY+LPS组培养液中IL-1β蛋白含量及小胶质细胞中IL-1βmRNA表达水平明显高于NPY+LPS组(P均<0.05),神经元凋亡率显著高于NPY+LPS组(P<0.05)。结论 NPY有可能通过其Y1受体降低过度激活的小胶质细胞免疫活性,抑制其生成IL-1β,从而减少大鼠皮质神经元凋亡。

Objective It is to explore the effect of neuropeptide Y（ NPY） on IL- 1B produced by microgliacytes in rats and the regulation on the apotosis of neurons. Methods The rat primary microgliacytes were cultured and divided into 5groups： control group,lipopolysaccharide（ LPS） group,NPY ＋ LPS group,NPY group,BIBP3226 ＋ NPY ＋ LPS group,which were respectively cultured by serum-free medium（ SFM）,SFM ＋ LPS,SFM ＋ NPY ＋ LPS,SFM ＋ NPY,BIBP3226 ＋NPY ＋ LPS. After culture for 6h,the content of IL- 1B in culture liquid in every group were detected by ELISA,the expression of IL- 1B were detected by RT- PCR. The apotosis of neurons were evaluated by Hoechst32258 staining. Results The contents of IL- 1B in culture liquid and the expression level of IL- 1B mRNA in microgliacytes in LPS group and apotossi rate were significantly higher than that in control group（ P 0. 05）,and these indexes in NPY ＋ LPS group were significantly lower than those in LPS group（ P 0. 05）,these indexes in BIBP3226 ＋ NPY ＋ LPS group were also higher than those in NPY ＋LPS group（ all P 0. 05）. Conclusion NPY can low down the over-activity of immunity of microgliacytes by its Y1 receptor,inhibit production of IL- 1B,thus to decrease the apotosis of neurons in the rats.