限制热量对NIT-1细胞胰岛素/胰岛素样生长因子通路及胰岛素分泌功能的影响  

Effects of CR on insulin/IGF-1 pathway and insulin secretion in NIT-1 cell

作　　者：朱志宏[1] 陈慎仁[1] 傅玉才[2] 魏炽炬[3] 杨杰华[1] 林超[1] 

机构地区：[1]汕头大学医学院第二附属医院内分泌科,广东汕头515041 [2]汕头大学医学院第二附属医院细胞衰老实验室,广东汕头515041 [3]汕头大学多学科研究中心

出　　处：《中国老年学杂志》2009年第11期1329-1333,共5页Chinese Journal of Gerontology

基　　金：广东省自然科学基金资助项目(No.5008346)

摘　　要：目的研究限制热量(CR)对胰岛素β瘤细胞(NIT-1)细胞胰岛素/胰岛素样生长因子(IGF-1)信号通路及胰岛素分泌功能的影响,为2型糖尿病(T2DM)的发病机制及防治提供实验依据和理论基础。方法NIT-1细胞培养至指数生长期,分别用PI3-K的阻断剂LY294002(LY)进行干扰,实验分成4组:对照组;CR组;LY+CR组;LY组。用RT-PCR、免疫细胞化学等方法检测Foxo1及其下游基因的转录及表达,用放射免疫及免疫细胞化学法检测胰岛素的分泌及表达,用细胞计数法检测细胞倍增周期。结果①CR可使NIT-1细胞倍增周期延长;②Foxo1主要定位于胞浆,阻断PI3-K后Foxo1从胞浆移入胞核,mRNA转录减少;③CR在正常状态及PI3-K通路障碍的细胞均可使Foxo1 mRNA转录增加,并影响其下游基因p27、Bim的转录;④PI3-K通路障碍可使NIT-1细胞胰岛素分泌增加,CR则可使PI3-K通路障碍的NIT-1细胞胰岛素分泌减少。结论CR不需通过上游PI3-K/Akt,可直接或间接作用于Foxo1参与对胰岛素/IGF-1信号通路的调控,延长细胞寿命,增强NIT-1细胞的糖耐量,改善胰岛素信号的传导及NIT-1的胰岛素分泌功能;可能参与了T2DM的发生发展。Objective To investigate the effects of Calorie Restriction （CR） on insulin/IGF-1 signal pathway and insulin secretion in the β neoplastic cell NIT-1. Methods NIT-1 cells were cultured to exponential growth phase in two different ways, one of which with high glucose medium, another glucose was negative. Then both of them were stimulated by LY294002 （LY）, the blocking agent of PI3-K. Samples were divided into LY, LY and CR, CR and DMSO groups as the control. The expressions of Foxol and its targets p27, Bim and FasL were detected by RT-PCR and immunocytochemical assay. The secretion and expression of insulin were detected by radioimmunity and immunocytochemieal assay. The cell multiplication cycle was measured by cytometry. Results①CR extended the cell multiplication cycle; ②Foxol was located in the kytoplasm, it moved into the nucleus and diminished its transcription when the PI3-K pathway was blocked;③CR increased the transcription of Foxol no matter the PI3-K pathway was blocked or not;④Insulin secretion was obviously increased when the PI3-K pathway was blocked, but CR could retune its effects. Conclusions It is unnecessary to go through the upstream of PI3-K/Akt, CR could directly or indirectly effect the activity of Foxol, so that to regulate the insulin/IGF-1 signal pathway, delay the aged proceeding of NIT-1 cells, strengthen the glucose tolerance, improve the conduction of insulin signal and the function of insulin secretion. Therefore, CR may participate in the generation and development of T2DM.

关 键 词：限制热量 胰岛素/胰岛素样生长因子 Foxol 胰岛素 2型糖尿病 

分 类 号：R587[医药卫生—内分泌]