同型半胱氨酸对小鼠骨骼肌组织PDK1的影响

目的 研究高同型半胱氨酸血症中骨骼肌组织PDK1的变化,探讨同型半胱氨酸对葡萄糖摄取的影响.方法 20只6周健康小鼠随机分为对照组(10只)和高同型半胱氨酸血症组(10只).3个月饮水中加入蛋氨酸(1.5%)复制高同型半胱氨酸血症模型,测定进食状态下血糖浓度.免疫组化检测骨骼肌细胞PDK1、PDK1磷酸化和Akt磷酸化的改变.Western Blot检测骨骼肌细胞PDK1与PDK1磷酸化和Akt与Akt磷酸化的表达.结果 与对照组比较,高同型半胱氨酸血症组进食血糖浓度增加(P<0.05),高同型半胱氨酸血症组骨骼肌细胞中PDK1、p-PDK1(ser-241)和p-Akt(Thr-308)平均灰度值增加(P<0.05);高同型半胱氨酸血症组骨骼肌组织PDK1、p-PDK1(Ser-241)和p-Akt(Thr-308)蛋白质水平下调(P<0.05),Akt的表达无差异(P>0.05).结论 同型半胱氨酸可能通过降低骨骼肌组织PDK1的表达和PDK1磷酸化,抑制对葡萄糖的摄取.

Effect of Homocysteine on PDK1 in Skeletal Muscle Tissue of Mice

Objective To investigate the expression of 3-phosphoinositide-dependent protein kinase 1(PDK1) in skeletal muscle tissue of hyherhomocysteinemia animal model,to explore the effect of homocysteine on glucose uptake.Methods Twenty healthy mice,six weeks of age,were randomly divided into control group(n = 10)and high hyperhomocysteinemia group(n =10).Normal food was fed in control group;Normal food and 1.5 %(mass fraction)methionine were fed in hyperhomocysteinemia group.After the feed in the hyperhomocysteinemia group and the control group were fed for three months,the levels of blood glucose were determined in the feeding.The variations of PDK1,phosphorylation of PDK1 and phosphorylation of Akt were observed with Immunohistochemistry in skeletal muscle cells.The expressions of PDK1,phosphorylation of PDK1,Akt and phosphorylation of Akt were determined with Western Blot in skeletal muscle tissue.Results The feeding plasma glucose in the hyperhomocysteinemia group were higher than that in the control group(P<0.05).The gray values of PDK1,p-PDK1(Ser-241)and p-Akt(Thr-308)were increased in the herpyhomocysteinemia group with Immunohistochemistry compared with the control group(P<0.05).The levels of PDK1,p-PDK1(Ser-241)and p-Akt(Thr-308)were the lower in the homocysteinemia group with Western Blot(P<0.05).However,the expression of Akt protein was not difference between the homocysteinemia group and the control group(P>0.05).Conclusion Homocysteine may decrease the expression of PDK1 and phosphorylation of PDK1 in skeletal muscle tissue,thus inhibits glucose uptake.