生长激素释放肽促进胰岛β细胞增殖的实验研究  

Ghrelin promotes proliferation and inhibits apoptosis of pancreatic β cells

作　　者：刘荣凤[1] 张捷[1] 胡晓舟[1] 王小林[1] 

机构地区：[1]北京大学第三医院检验科,100083

出　　处：《中华检验医学杂志》2008年第9期1039-1042,共4页Chinese Journal of Laboratory Medicine

摘　　要：目的研究生长激素释放肽（ghrelin）对胰岛β细胞（NIT-1）增殖的影响，并初步探讨其作用机制。方法采用不同浓度的ghrelin在不同时间内对NIT-1细胞进行刺激，以噻唑蓝（MTT）法观察ghrelin对NIT-1细胞增殖的影响；采用流式细胞术检测ghrelin对细胞周期的影响；采用免疫印迹法（Westernblot）分析细胞外信号调节激酶（ERK1/2）表达水平和ERK1/2磷酸化水平。结果随着ghrelin浓度的增加和作用时间的延长，发现其有促进NIT-1细胞增殖的作用。ghrelin作用于NIT-1细胞48h后，改变细胞S期所占比例，ghrelin浓度为0、10^-9、10^-8、10^-7mol／L时，对应的S期细胞所占比例分别为（34．5±6．5）％、（42．1±7．4）％、（50．6±5．8）％、（71．4±9．4）％。ghrelin处理NIT-1细胞后，ERK1/2出现磷酸化，且磷酸化水平与ghrelin浓度呈剂量-效应关系。结论ghrelin通过激活丝裂原活化蛋白激酶（MAPK）／ERK1/2途径，影响细胞周期，促进胰岛β细胞增殖。Objective To investigate the role of ghrelin promoting proliferation of pancreatic β cells and the mechanism of it. Methods Mouse pancreatic β cells （NIT-1） were treated with different concentrations of ghrelin. NIT-1 cells proliferation was measured by MTT incorporation assay, and the cell cycle was measured by Flow Cytometry, and the expression of ERK1/2 and the level of ERK1/2 phosphorylation were determined by Western blot assay. Results With the increase of concentration and the time of treatment, ghrelin promotes cell survival of pancreatic β cells. The S-phase portion was changed after treatment of ghrelin on NIT-1 for 48 hours. The S-phase percentage in the groups where ghrelin concention change from 0 to 10^-9,10^-8,10^-7 mol/L were （34.5 ±6.5）%,（42.1 ±7.4）%, （50.6 ±5.8）%, （71.4 ± 9.4）% , respectively. Ghrelin also induces phosphorilation of ERK1/2 in NIT-1 cell, and a doseeffect relationship was demonstrated. Conclusion Ghrelin could promote proliferation of pancreatic β cells through activating the MAPK/ERK1/2 signaling pathway and changing the cell cycle.

关 键 词：胰岛 细胞增殖 肽类激素 

分 类 号：R686[医药卫生—骨科学]