AMPK-α表达变化在糖尿病患者骨骼肌脂肪酸代谢和胰岛素抵抗中的作用

Expression Changes of AMPK-alpha in Skeletal Muscle Fatty Acid Metabolism and Insulin Resistance in Patients with Diabetes Mellitus

目的探讨腺苷酸活化蛋白激酶α(AMPK-α)表达变化在糖尿病患者骨骼肌脂肪酸代谢和胰岛素抵抗中的作用.方法在骨科行髋关节和下肢手术的患者中选取Ⅱ型糖尿病病程≤5 a的患者20例为研究组,另选取行骨科手术的非糖尿病患者20例为对照组.抽取空腹静脉血检测血生化指标;骨科术中留取骨骼肌组织,测定骨骼肌TG、长链脂酰辅酶A(LCACo A)水平;RT-PCR法检测骨骼肌AMPK-α1,AMPK-α2 mRNA水平;Western blotting法检测骨骼肌AMPK-α1,AMPK-α2和磷酸化AMPK-α蛋白水平.结果研究组空腹血糖、糖化血红蛋白、胰岛素、TG、FFA水平均明显高于对照组,ISI明显低于对照组,差异具有统计学意义(P<0.05);研究组骨骼肌TG,LCACo A含量均明显高于对照组,差异具有统计学意义(P<0.05).研究组和对照组AMPK-α1 mRNA拷贝数之间差异无统计学意义(P>0.05);研究组AMPK-α1 mRNA拷贝数明显低于对照组,差异具有统计学意义(P<0.05).研究组和对照组AMPK-α1蛋白表达量之间差异无统计学意义(P>0.05);研究组AMPK-α2和磷酸化AMPK-α蛋白水平明显低于对照组,差异具有统计学意义(P<0.05).结论Ⅱ型糖尿病患者易发生脂肪酸代谢异常和胰岛素抵抗,AMPK-α2表达和AMPK-α活性改变在骨骼肌脂质堆积和胰岛素抵抗中发挥关键作用.

Objective To investigate the role of the expression changes of adenosine monophosphate activated protein kinase alpha（AMPK-α） in skeletal muscle fatty acid metabolism and insulin resistance in patients with diabetes mellitus.Method 20 patients with type 2 diabetes for 5 or less than 5 years from the patients who had undergone hip and lower limb surgery were selected as study group,and 20 non-diabetic patients who had undergone the orthopedic operations were selected as control group.The patients fasting venous blood samples were taken for the detection of biochemical indexes,the skeletal muscle tissue was left during the orthopedic surgeries for the determination of TG and long chain fatty acyl coenzyme A（LCACo A） levels in the skeletal muscle.RT-PCR method was used to detect the level of AMPK-α1 and AMPK-α2 mRNA in the skeletal muscle;Western blotting was used to detect the level of AMPK-α1 and AMPK-α2,and phosphorylated AMPK-α protein in the skeletal muscle.Results Fasting blood glucose,glycosylated hemoglobin,insulin,TG and FFA levels weresignificantly higher than those in the control group,ISI was significantly lower than that in the control group,and the difference was statistically significant（P〈0.05）;TG and LCACo A in the skeletal muscle in the study group were obviously higher than those in the control group,with statistically significant differences（P〈0.05）.There was no significant difference in the number of AMPK-α1 mRNA copy between the study group and the control group（P〈0.05）;the AMPK-α1 mRNA copy number in the study group was significantly lower than that in the control group,showing a statistically significant difference（P〈0.05）.The difference in AMPK-α1 protein expression was not statistically significant between the study group and the control group（P〈0.05）;the AMPKalpha 2 and phosphorylated AMPK-α protein levels in the study group were significantly lower than those in the control group（P〈0.05）.Conclusion The abnormal fatty acid metabolism and insulin resistance are common in patients with type 2 diabetes mellitus,the expression of AMPK-α2 and the changes of AMPK-α activity play a key role in the lipid accumulation and insulin resistance in skeletal muscle.