【摘要】 目的探讨生物钟基因brain and muscle Arnt-like protein-1（Bmal1）对胰岛β细胞凋亡的调节作用。方法实验分为正常对照组（含5.5mmol/L葡萄糖,NC组）、高糖组（含33.3mmol/L葡萄糖）、正常糖浓度+无关RNA转染组（含5.5mmol/L葡萄糖,NC+si RNA组）、正常糖浓度+Bmal1基因沉默组(NC+Bmal1^-/-组)、高糖+无关RNA转染组（含33.3mmol/L葡萄糖,高糖+si RNA组）、高糖+Bmal1基因沉默组(高糖+Bmal1^-/-组)。NC组不加干预因素。采用RNA干扰技术沉默大鼠胰岛β细胞瘤株（INS-1）Bmal1基因,应用TUNEL法检测细胞凋亡,流式细胞仪检测活性氧（ROS）含量,ATP检测试剂盒测定三磷酸腺苷（ATP）含量,实时荧光定量PCR检测Bmal1、去乙酰化酶sirtuin 1（Sirt1）m RNA表达情况。结果与NC+si RNA组比较,NC+Bmal1^-/-组ATP含量下降,ROS水平增加,Sirt1 m RNA表达下降（均P<0.01）。与NC组比较,高糖组ATP下降,ROS增加,Sirt1 m RNA表达下降（均P<0.01）,细胞凋亡增加（P<0.05）。与高糖+si RNA组比较,高糖+Bmal1^-/-组ATP下降,ROS增加,细胞凋亡增加（均P<0.01）,Sirt1 m RNA表达有下降趋势,但无统计学差异（P>0.05）。结论 Bmal1可通过调节氧化应激信号通路影响胰岛β细胞功能和凋亡。更多还原

【Abstract】 Objective To investigate the role of the clock gene brain and muscle Arnt-like protein-1（Bmal1） in pancreatic β-cells.Methods The rat insulinoma INS-1 cells were divided into 6 groups: control group, high glucose（33.3 mmol/L） group, normal glucose（5.5 mmol/L） + si RNA group, normal glucose+Bmal1^-/-group, high glucose+siRNA group, high glucose+Bmal1^-/-group. No intervention was applied to the control group. INS-1 cells were transfected with small interfering RNA（si RNA） to knock down the expression of Bmal1. Cell apoptosis, ROS production, and ATP level were determined by TUNEL assay, flow cytometry and enhanced ATP assay kit, respectively.Real-time quantitative RT-PCR was used to detect the expression of Bmal1 and Sirt1 m RNA. Results Knockdown of Bmal1 gene significantly attenuated ATP level and Sirt1 m RNA expression（P<0.01）, while caused an increase in ROS production（P<0.01）. Compared with the control group, high glucose caused a decrease in Sirt1 m RNA expression and ATP level（P<0.01）, with an increase in ROS accumulation（P<0.01） and cell apoptosis（P<0.05）. These alterations were more pronounced in cells lacking of Bmal1 cultured in a high glucose medium（P<0.01）, Sirt1 m RNA expression had a trend to decrease（P >0.05）. Conclusion The biological clock gene Bmal1 regulates oxidative stress, and has an important role in pancreatic β-cell apoptosis.更多还原