Xu Jianfeng, Li Lin, Qian Zhikang, Hong Jie, Shen Shuiyuan, Huang Weida
Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China.
Biochem Biophys Res Commun. 2005 Apr 8;329(2):538-43. doi: 10.1016/j.bbrc.2005.02.016.
Metabolic deregulation accompanying type II diabetes is characterized by insulin resistance in peripheral tissues (liver, muscle, and adipose), mediated by impairments in insulin receptor (IR) signaling. Protein tyrosine phosphatase 1B (PTP1B) has been shown to be a negative regulator of IR autophosphorylation and thus has been considered as a major therapeutic target for the treatment of type II diabetes. We use RNA interference technique to downregulate PTP1B expression in hepatoma cell line. A secretory HBV s-antigen was introduced as reporter and driven by mouse fatty acid synthase promoter, which is positively controlled by insulin signaling. Liver-targeted hydrodynamic injection in tail vein was introduced to transfer siRNA (or siRNA expression vector) and reporter plasmid into mouse liver. On fasted/refed and glucose stimulation condition, the HBV s-antigen in sera in RNAi group was higher than that in the negative group. Our results provided evidence that upregulation of insulin signaling by reducing PTP1B liver with RNAi can be a potent diabetes treatment method.
伴随II型糖尿病的代谢失调的特征是外周组织（肝脏、肌肉和脂肪）出现胰岛素抵抗，这是由胰岛素受体（IR）信号传导受损介导的。蛋白酪氨酸磷酸酶1B（PTP1B）已被证明是IR自磷酸化的负调节因子，因此被认为是治疗II型糖尿病的主要治疗靶点。我们使用RNA干扰技术下调肝癌细胞系中PTP1B的表达。引入分泌型乙肝表面抗原作为报告基因，并由小鼠脂肪酸合酶启动子驱动，该启动子受胰岛素信号正调控。采用尾静脉肝靶向流体动力学注射法将siRNA（或siRNA表达载体）和报告质粒导入小鼠肝脏。在禁食/再喂食和葡萄糖刺激条件下，RNAi组血清中的乙肝表面抗原高于阴性组。我们的结果表明，通过RNAi降低肝脏中PTP1B来上调胰岛素信号传导可能是一种有效的糖尿病治疗方法。
