JAZF1过表达对糖异生及胰岛素信号通路的影响

Effect of JAZF1 over-expression on gluconeogenesis and insulin signal pathway

摘要:

目的：在课题组前期细胞研究结果的基础上构建锌指并列基因1（juxtaposed with another zinc finger gene 1，JAZF1）转基因动物模型并探讨JAZF1基因过表达对糖异生及胰岛素信号通路的影响。方法：将构建和制备的JAZF1基因片段，经显微注射到受精卵中，将受精卵移植入受体小鼠，产出后经鉴定和繁育得到较纯的JAZF1转基因小鼠。将8周龄转基因小鼠（Tg-JAZF1）和野生（wild type，WT）小鼠随机分为4组喂养：即普食（standard diet，SD）-WT组（n=6）、SD-Tg组（n=6）、高脂（high fat diet，HFD）-WT组（n=6）、HFD-Tg组（n=6）。各组小鼠喂养12周之后测定肝脏组织糖异生的关键基因葡萄糖-6-磷酸酶（glucose-6-phosphatase，G-6pase）和磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxykinase，PEPCK）的mRNA和蛋白表达的变化。Western blot测定肝脏、肌肉、脂肪组织胰岛素信号通路蛋白磷酸化水平变化。结果：SD-Tg小鼠的mRNA和蛋白在肝脏、肌肉、脂肪组织中表达较SD -WT小鼠均明显升高，差异具有统计学意义（P<0.05）；与WT小鼠比较，Tg-JAZF1小鼠肝脏PEPCK、G-6-Pase在SD喂养和HFD喂养条件下mRNA水平和蛋白表达水平均明显降低，差异具有统计学意义（P<0.05）；肝脏组织胰岛素信号通路蛋白磷酸化水平均增加，差异具有统计学意义（P<0.05）。结论：JAZF1转基因动物模型构建成功，JAZF1过表达能抑制肝脏糖异生关键基因表达，增加肝脏组织的胰岛素敏感性。

Abstract:

Objective：To establish juxtaposed with another zinc finger gene 1（JAZF1）-transgenic mice model on the basic of cell re－search in vitro and to explore the effect of JAZF1 over-expression on gluconeogenesis and insulin signal pathway. Methods：The pre－pared JAZF1 gene fragment was microinjected into one-cell embryos of mice，then the JAZF1-transgenic mice were generated and i－dentified by standard procedures. Eight-week-old Tg-JAZF1（Tg） mice and wild type（WT） mice were randomly divided into 4 groups：standard diet（SD）-WT group（n=6），SD-Tg group（n=6），high fat diet（HFD）-WT group（n=6） and HFD-Tg group（n=6）. Phospho－enolpyruvate carboxykinase and glucose-6-phosphatase in liver were detected by PCR and Western blot after 12 weeks. The phos－phorylation of insulin signal protein was measured by Western blot. Results：JAZF1 mRNA and protein expressions in liver，muscle and adipose tissue were elevated significantly in SD-Tg mice than in SD-WT mice（P<0.05）.The expressions of gluconeogenesis gene in Tg mice were dramatically decreased compared with those of WT mice under the condition of SD or HFD（P<0.05）. The phospho－rylation of insulin signal protein in liver，muscle and adipose tissue were increased in Tg mice than in WT mice（P<0.05）. Conclusion：Transgenic mice model has been generated successfully. JAZF1 overexpression inhibit the expression of gluconeogenesis gene and also improve the insulin sensitivity of liver，muscle and adipose tis－sue.