过表达人载脂蛋白M基因对GK大鼠胰岛素敏感性的影响

Effect of overexpression of human apolipoprotein M gene on insulin sensitivity in the Goto-Kakizaki rats

目的 探讨过表达人载脂蛋白M（ApoM）基因是否改善Goto-Kakizaki （GK）大鼠胰岛素敏感性.方法 以慢病毒（LV）为载体,构建含人ApoM基因的重组慢病毒[LV4 （GFP）-ApoM].转染293T细胞24 h后,采用聚合酶链反应（PCR）芯片分析2型糖尿病相关基因;将10只GK大鼠随机分为ApoM阴性慢病毒组和ApoM阳性慢病毒组,每组5只.尾静脉注射5＆#215;108 TU慢病毒,用实时定量PCR（Real-time PCR）法检测ApoM mRNA水平,胰岛素耐量实验评价GK大鼠胰岛素敏感性.结果 （1）相较于ApoM阴性慢病毒组,293T细胞ApoM阳性慢病毒组ApoM mRNA水平增加79.43倍（P＜0.01）;同时,与胰岛素抵抗相关的基因丝裂原活化蛋白激酶8（MAPK8）下调了2.11倍（P＜0.05）,胰岛素样生长因子2（IGF2）下调1.23倍（P＜0.05）.（2）ApoM阳性慢病毒组GK大鼠肺组织中人ApoM mRNA表达较为明显;第14天GK大鼠空腹血糖水平和对照组之间的差异无统计学意义（P＞0.05）,但胰岛素耐量实验结果显示ApoM阳性慢病毒组GK大鼠血糖浓度下降50％的时间（60 min）明显早于ApoM阴性对照组（90 min）.结论 过表达ApoM基因有可能增强2型糖尿病个体的胰岛素敏感性.

Objective To explore whether transfection of human apolipoprotein M （ApoM） gene can improve insulin sensitivity in the Goto-Kakizaki （GK） rats.Methods Hunan ApoM gene was inserted into lentivirus to construct LV4 （GFP）-ApoM expression vector,which was transfected into the 293T cells for 24 h.Polymerase chain reaction（PCR） was applied for analyzing the expression of genes those related to the type 2 diabetic mellitus.Ten rats were divided randomly into two groups [LV4 （GFP）-NC group and LV4 （GFP）-ApoM group] （n =5 each）.GK rats were injected with the lentiviral vector-mediated 5 ＆#215; 108 TU human ApoM overexpression system,and insulin tolerance test （ITT） was assessed.Human ApoM expression was detected by real-time quantitative polymerase chain reaction （Real-time PCR）.Results The gene related to insulin resistance,mitogen-activated protein kinase 8 （MAPK8） was down-regulated to 2.11-fold （P 〈 0.05）,and insulin like growth factor 2 （IGF2） down-regulated to 1.23-fold （P 〈 0.05）,while ApoM expression levels in 293T cells transfected with human ApoM gene were increased to 79.43-fold （P 〈 0.01）.Human ApoM mRNA was significantly expressed in the lung of GK rats in LV4 （GFP）-ApoM group.Interestingly,ITT analysis showed that the time of blood glucose dropped to 50% from baseline value in GK rats transfected with human ApoM gene （60 min） was shorter than that of control rats （90 min）.Conclusion Overexpression of ApoM gene could improve insulin sensitivity of individuals with type 2 diabetes.