不同糖耐量人群血浆25-羟维生素D与葡萄糖转运子4及胆固醇调节元件结合蛋白1C表达关系的研究

摘要

目的 探讨不同糖耐量人群血浆25-羟维生素D[25(OH)D]与葡萄糖转运子4(GluT-4)及胆固醇调节元件结合蛋白1C(SREBP-1C )表达的关系.方法 随机分为T2DM组、IGR组及正常对照(NGT)组.检测血糖、血脂、HbA1c等,电化学发光法测定25(OH)D和FIns.Western blot 检测 GluT-4及SREBP-1C蛋白的表达,RT-PCR检测GluT-4和SREBP-1C mRNA的表达.结果 T2DM组、IGR组25(OH)D低于NGT组 [(8.77±4.52) vs (18.35±5.90) vs (30.67±5.47) ng/ml,P<0.05],T2DM组低于IGR组(P<0.05).T2DM组、IGR组血浆GluT-4 mRNA及蛋白表达低于NGT组[(0.235±0.412) vs (3.386±0.698) vs (6.325±0.959),(1.235±0.092) vs (2.430±0.153) vs (4.843±0.299),P<0.05],T2DM组较IGR组降低(P<0.05).T2DM组、IGR组血浆中SREBP-1C mRNA及蛋白表达水平高于NGT组[(7.570±1.233) vs (5.561±0.820) vs (2.880±0.483),(8.340±1.092) vs (5.279±0.798) vs (2.340±0.135),P<0.05],T2DM组较IGR组升高(P<0.05).Pearson相关性分析显示,25(OH)D与血浆中GluT-4 mRNA、蛋白表达呈正相关(P<0.05),与HbA1c、HOMA-IR、FIns、FPG、2 hPG、TG及SREBP-1C mRNA、SREBP-1C蛋白表达呈负相关(P<0.05).血浆中GluT-4表达与SREBP-1C表达呈负相关(P<0.05).结论 血浆25(OH)D降低可引发糖耐量异常,甚至导致糖尿病,其机制可能与血浆中GluT-4表达降低及SREBP-1C表达升高有关.%Objective To study the relationship between plasma 25(OH)D levels and the expression of glucose transporter 4 (GluT-4 mRNA) and SREBP-1C among patients with different glucose tolerance.Methods The subjects were divided into type 2 diabetes mellitus (T2DM group),impaired glucose regulation (IGR group) and normal glucose tolerance (NGT group).Electrochemical luminescence method was used to determine the levels of plasma 25(OH)D and insulin,the homeostasis model was used to evaluate the degree of insulin resistance (HOMA-IR).The metabolic parameters including blood lipid,fasting glucose (FPG) and,HbA1c were detected,GluT-4 and SREBP-1c mRNA and protein expression were determined by Western blot and real time PCR.Results The levels of 25(OH)D was significantly lower in T2DM group and IGR group than that in NGT group,with much lower level in T2DM group than that in IGR group [(8.77±4.52) vs (18.35±5.90) vs (30.67±5.47) ng/ml,P<0.05].The levels of GluT-4 mRNA and its protein expression were significantly lower in T2DM group and IGR group than those in NGT group,with much lower levels in T2DM group than those in IGR group [(0.235±0.412) vs (3.386±0.698) vs (6.325±0.959),P<0.05].The levels of SREBP-1C mRNA and its protein expression were significantly higher in T2DM group and IGR group than those in NGT group [(7.570±1.233) vs (5.561±0.820) vs (2.880±0.483),P<0.05],with much higher levels in T2DM group than those in IGR group (P<0.05).Pearson correlation analysis indicated that 25(OH)D levels were positively correlated with GluT-4 mRNA and protein expression (P<0.05),and negatively correlated with HbA1c,HOMA-IR,FIns,FPG,2 hPG,TG,SREBP-1C mRNA and protein expression (P<0.05).GluT-4 mRNA and protein expression had a negative correlation with SREBP-1CmRNA and protein expression (P<0.05).Conclusion The decline of serum 25(OH)D may involved in the development of impaired glucose tolerance and even diabetes mellitus,which may be related to decreased GluT-4 expression and increased SREBP-1C expression.