Expression Of Nampt In Tissues Of Type2Diabetes Mellitus Rats And Its Action In β-cells Under The Condition Of Oxidative Stress

Objective:To detect pathologic change of Nampt in type2diabetes mellitus and observe the effects of β-cell by regulating it, and the role of Nampt on the pathogenesis of type2diabetes mellitus, it lays the foundation for the pathogenesis of diabetes mellitus. Methods:1. In the Whole level experiment, we Copy the SD rats model of type2diabetes mellitus, and detect the expression of Nampt in different tissues by immunohistochemical assay.2. In the vitro experiment, through application of NIT-1cell line, the cells are divided into four groups:5.6mmol/L,11.1mmol/L, and16.7mmol/L,27.6mmol/L. Nampt was recombined with CSII-EF-MCS-IRES2-Venus plasmid vectors successfully, then transfected into NIT-1cells with lipofection of Nucleofection agent. The of Nampt and Foxol expression were detected by Western Blot assay. The relationship of both gene expression, insulin secretion were measured. Results:1. Pathologic tissues sections of type2diabetes mellitus showed that the positive expression rate of Nampt in liver in type2diabetes mellitus was significantly higher than in healthy control (P<0.05); and the expression level was lower in pancreas in type2diabetes mellitus group(p<0.05). But there was no significant difference in skeletal muscle and kidney between in type2diabetes mellitus SD rats and healthy control.2. The recombinant plasmid of Nampt-CSII-EF-MCS-IRES2-Venus was transfected in NIT-1cells, when cultured for24hours, green fluorescence protein was observed by fluorescence microscopy. And western blot analysis indicated that there were significant different between the expression of Nampt and Foxol before and after transfection in each group. Nampt protein expression increased after the transfection, but the expression of Foxol decreased after the transfection (P<0.05). The level of insulin increased after the transfection (P<0.05). Conclusions:1. Nampt was expressed differently in different tissuses between in type2diabetes mellitus and healthy control; Nampt expression in liver in type2diabetes mellitus was higher than in healthy control (The pancreas instead); But there was no significant difference in skeletal muscle and kidney of SD rats between in type2diabetes mellitus and healthy control. The Nampt play an important role in type2diabetes mellitus pathogenesis.2. Up-regulation of Nampt in cell can inhibit FoxO1expression under the oxidative stress state, and promote β-beta cell proliferation and insulin secretion. It is showed that oxidative stress made islet (3-beta cell damaged can cause NAMPT changed.