白细胞介素1β和干扰素γ对小鼠胰岛素瘤βTC-6细胞胰岛素分泌功能的影响

摘要

目的 探讨炎性细胞因子白细胞介素1β(IL-1β)、干扰素γ(IFN-γ)对小鼠胰岛β细胞株βTC-6胰岛素分泌功能的影响.方法 将βTC-6细胞培养于高糖DMEM培养基,48 h后换用无糖KRBII缓冲液培养30 min,分别于含0、1.38、5.50和11.10 mmol/L葡萄糖的KRBH缓冲液中孵育60 min,放射免疫法检测细胞上清液中胰岛素水平(GSIS).在βTC-6细胞中分别加入不同浓度的IL-1β(0.15、1.50μg/L)和(或)IFN-γ(10、100U/ml),24 h后换用无糖KRBH缓冲液培养30 min,在含1.38 mmol/L葡萄糖的KRBH缓冲液中孵育60min,放射免疫法检测细胞上清液中胰岛素水平.多组间数据比较采用单因素方差分析,两组间数据比较采用t检验.结果 βTC-6细胞在1.38 mmol/L葡萄糖刺激时胰岛素分泌达高峰,与无葡萄糖刺激时相比差异有统计学意义[(151±14)对(120±4)mU/L,t=-4.215,P=0.006]；550、11.10 mmol/L葡萄糖刺激时胰岛素分泌较1.38mmol/L葡萄糖刺激时明显下降(均P ＜0.05).与单纯1.38mmol/L葡萄糖刺激组相比,IL-1β(0.15μg/L)组[(85.53±5.06)mU/L对(103.11±0.27)mU/L,t=4.897,P=0.039]、IL-1β(1.50μg/L)组[(62.62±0.64)mU/L对(103.11±0.27)mU/L,t=212.66,P＜0.001]葡萄糖刺激下胰岛素分泌水平显著下降,下降程度与IL-1β的剂量呈正相关；与单纯葡萄糖刺激组相比,IFN-γ(100U/ml)组葡萄糖刺激下胰岛素分泌显著下降[(73.2±1.6)对(105.2±1.8)mU/L,=19.52,P=0.003]；与IL-1β(0.15 μg/L)组及IFN-γ( 100 U/ml)组相比,1L-1β联合IFN-γ组葡萄糖刺激下胰岛素分泌显著下降(F =77.38,P＜0.001).结论 IL-1β和IFN-γ对βTC-6细胞的胰岛素分泌功能有抑制作用,且两者间具有协同效应.%Objective To investigate the effect of interleukin(IL)-1β and interferon(IFN)-γ on the insulin secretion in mice βTC-6 cells in vitro.Methods βTC-o cells were cultured in DMEM for 48 hours then pre-incubated for 30 minutes in Krebs-Ringer bicarbonate-Hepes (KRBH) buffer without glucose. The KRBH was then discarded and replaced with fresh buffer containing 1.38 mmol/L or 5.50 mmol/L or 11.10 mmol/L glucose for 1 hour. Supernatants were collected for insulin assays by an insulin radioimmunoassay (RIA) kit (GSIS).IL-lβ(0.15,1.50μg/L)and/or IFN-γ(10,100 U/ml)were added in βTC-6 cells for 24 hours then GSIS was measured as indicated with 1.38 mmol/L glucose stimulation.Data were analyzed by ONE-way ANOVA with correction for multiple comparisons or by Student's t-test for comparison between two groups. Results The insulin level reaches a peak in 1.38 mmol/L stimulation group compared with 0 mmol/L glucose stimulation group ( ( 151 ± 14) vs ( 120 ±4) mU/L,t =- 4.215,P =0.006). The insulin level 5.50 mmol/L and 11.10 mmol/L glucose stimulation groups were significantly lower than that in 1.38 mmol/L glucose stimulation group ( all P ＜0.05 ). Compared with 1.38 mmol/L glucose stimulation alone group,the insulin level was significantly lower in IL-1β (0.15 μg/L) group ((85.53 ±5.06) vs (103.11±0.27) mU/L,t=4.897,P=0.039);IL-1β( 1.50 μg/L) group ( ( 62.62 ± 0.64) vs (103.11±0.27 )mU/L,t =212.66,P＜0.001) and IFN-γ (100U/ml) group ( (73.2±1.6) vs (105.2±1.8)mU/L,t=19.52,P=0.003).Compared with IL-1β (0.15μg/L) and IFN-γ( 100 U/ml)groups,the insulin level in 1.38 mmol/L glucose stimulation with IL-1β3 plus IFN-γ group was significantly lower ( F=77.38,P＜O.001).Conclusion IL-1 βor IFN-γalone can inhibit the glucose-induced insulin secretion in βTC-6 cells or in a synergistic manner.