CAJ | 학술논문

目的观察Sirt2特异性抑制剂AGK-2对大鼠胰岛葡萄糖刺激的胰岛素分泌的影响,并探讨其可能机制.方法用免疫组化和免疫细胞化学技术观察Sirt2在胰腺组织、单个胰岛β细胞的表达情况;将分离的大鼠胰岛置于24孔培养板培养,分别在2.8和16.7 mmol/L葡萄糖条件下加AGK-2处理lh后,收集上清,检测胰岛素浓度；抽提蛋白,以Western印迹法检测d-tubulin乙酰化水平；用离子成像技术检测单个胰岛β细胞钙离子浓度的变化.结果免疫组化结果显示,在胰腺中Sirt2主要表达在β细胞胞浆中;Sirt2的特异性抑制剂AGK-2对基础胰岛素分泌无显著影响,但使16.7 mmol/L葡萄糖刺激的胰岛素分泌降低,呈剂量依赖性,5μmol/L AGK-2能使胰岛素分泌降低75％；离子成像技术结果显示,AGK-2显著抑制高糖引起的钙离子浓度增加.结论 Sirt2抑制剂AGK-2可能通过抑制高糖刺激的β细胞钙离子浓度的增加降低胰岛素分泌.
목적 관찰Sirt2특이성억제제AGK-2대대서이도포도당자격적이도소분비적영향,병탐토기가능궤제.방법 용면역조화화면역세포화학기술관찰Sirt2재이선조직、단개이도β세포적표체정황;장분리적대서이도치우24공배양판배양,분별재2.8화16.7 mmol/L포도당조건하가AGK-2처리lh후,수집상청,검측이도소농도；추제단백,이Western인적법검측d-tubulin을선화수평；용리자성상기술검측단개이도β세포개리자농도적변화.결과 면역조화결과현시,재이선중Sirt2주요표체재β세포포장중;Sirt2적특이성억제제AGK-2대기출이도소분비무현저영향,단사16.7 mmol/L포도당자격적이도소분비강저,정제량의뢰성,5μmol/L AGK-2능사이도소분비강저75％；리자성상기술결과현시,AGK-2현저억제고당인기적개리자농도증가.결론 Sirt2억제제AGK-2가능통과억제고당자격적β세포개리자농도적증가강저이도소분비.
Objective To observe the effect of AGK-2,a specific inhibitor of Sirt2,on insulin secretion of ratislets,and to explore the possible mechanism.Methods The expression of Sirt2 in pancreatic tissue and single primary β cell was observed by immunohistochemistry and immunocytochemistry.After the isolated rat islets in 24-cell plates were incubated with AGK-2 for 1 h in the presence of 2.8 and 16.7 mmol/L glucose,the culture medium was taken for insulin assay with RIA.Protein was extracted from islets for detecting the acetylation of α-tubulin with Western blot.The change of Ca2+ concentration in single pancreatic β cell was detected by ion imaging technology.Results The immunohistochemistry result showed that Sirt2 was largely expressed in cytoplasm of β cell in the islet of pancreas.Sirt2 was mainly located in cytoplasm of β cell.AGK-2 inhibited glucose-stimulated insulin secretion in a dose-dependent manner,without effect on basal insulin secretion.At the concentration of 5 μmol/L,AGK-2 decreased insulin secretion by 75％.The ion imaging technology showed that high glucose-stimulated Ca2+ increase was decreased by AGK-2.Conclusion The specific inhibitor of Sirt2,AGK-2 inhibited glucose-stimulated insulin secretion by decreasing the concentration of Ca2+ in β cells.