γ-射线诱导Jurkat细胞凋亡过程中催乳素对Bcl-2及Bax表达的调节

Prolactin effects on Bcl-2 and Bax expression during Jurkat cell apoptosis induced by gamma-irradiation

背景:国内外文献表明,催乳素可通过调节细胞内凋亡相关蛋白的表达促进免疫细胞增殖并抑制细胞凋亡。目的:拟验证催乳素是否能通过调节T细胞Bax和Bcl-2的表达来影响Jurkat细胞凋亡。设计、时间及地点:以细胞为对象的对比观察实验,于2006-07/2007-05在新乡医学院免疫学实验室完成。材料:人白血病T细胞株Jurkat细胞为上海生工产品,人催乳素为sigma公司产品。方法:以10Gyγ-射线照射Jurkat细胞建立细胞凋亡模型。在射线照射前30min内,于模型中分别加入20μg/L,300μg/L和1000μg/L的人催乳素进行干预,同时设不含人催乳素的对照组,以及不进行辐射处理且不加催乳素的正常组。于辐射后的0,24,48h收集细胞。主要观察指标:以四甲基偶氮唑盐法检测Jurkat细胞的增殖情况;以流式技术检测细胞凋亡情况;以琼脂糖凝胶电泳检测Jurkat细胞凋亡DNA;以WesternBlot法检测Jurkat细胞内凋亡相关蛋白Bcl-2和Bax表达水平。结果:①在γ-射线处理后24和48h,与对照组比较,300μg/L和1000μg/L催乳素组和正常组的细胞数量明显增多(P<0.01)。②在细胞经γ-射线处理后48h,与对照组比较,300μg/L和1000μg/L催乳素组和正常组细胞凋亡率显著降低(P<0.05)。③在γ-射线处理后的24和48h,与对照组比较,各质量浓度催乳素组Bcl-2/β-actin灰度比值均明显升高(P<0.01);300μg/L和1000μg/L催乳素组Bax/β-actin灰度比值明显降低(P<0.01)。结论:在γ-射线诱导的Jurkat细胞凋亡过程中,催乳素可通过提高Bcl-2的表达并下凋Bax的表达,来抑制Jurkat细胞凋亡。

BACKGROUND： Prolactin can promote immunocyte proliferation and inhibit cell apoptosis by regulating apoptosis-associated protein expression. OBJECTIVE：To investigate efforts of prolactin on Jurkat cell apoptosis by regulating T cells Bax and Bcl-2 expression. DESIGN, TIME AND SETTING： The control cell experiment was performed at the Immunology Lab of Xinxiang Medical College from July 2006 to May 2007. MATERIALS： Human prolactin （Sigma, USA） and Jurkat cells （Sangon, Shanghai） were used in this study. METHODS： Apoptosis models of Jurkat cells induced by 10 Gy γ -irradiation were established. In 30 minutes before irradiation, 20 μg/L, 300 μg/L and 1 000 μg/L human prolactin were injected into models. Control group, which without prolactin was set up at the same time, as well as normal group, which without irradiation and prolactin. Cells were collected at 0, 24 and 48 hours after irradiation. MAIN OUTCOME MEASURES： The proliferation of Jurkat cells was detected by MTT. The apoptosis rate of Jurkat cells was tested by flow Cytometry and DNA by electrophoresis ladder. The contents of Bax and Bcl-2 of Jurkat cells were measured by Westem Blot. RESULTS： The proliferation of Jurkat cells was significantly increased in 300 μg/L and 1000 μg/L prolactin groups and normal group compared to control group in 24 and 48 hours （P 〈 0.01）. Cell apoptotic rate was decreased in 300 μg/L and 1000 μg/L prolactin groups and normal group compared to control group after irradiated for 48 hours （P 〈 0.05）. After irradiated for 24 and 48 hours, Bcl-2/β-actin gray value was significantly increased in each prolactin groups compared to the control group （P 〈 0.01）. Bcl-2/β -actin gray value was significantly decreased in the 300 μ g/L and 1 000 μg/L prolactin groups （P 〈 0.01）. CONCLUSION： In the process of Jurkat cells apoptosis induced by γ -irradiation, prolactin can inhibit Jurkat cell apoptosis by elevating Bcl-2 expression and down-regulate Bax expression.