Forkhead box O1 mediates defects in palmitate-induced insulin granule exocytosis by downregulation of calcium/calmodulin-dependent serine protein kinase expression in INS-1 cells
Forkhead box O1 mediates defects in palmitate-induced insulin granule exocytosis by downregulation of calcium/calmodulin-dependent serine protein kinase expression in INS-1 cells
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Forkhead box O1 通过下调 INS-1 细胞中钙/钙调蛋白依赖性丝氨酸蛋白激酶的表达介导棕榈酸酯诱导的胰岛素颗粒胞吐作用缺陷
DOI：
10.1007/s00125-015-3561-4
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发表时间：
2015-03
期刊：
影响因子：
8.2
通讯作者：
韩晓
中科院分区：
文献类型：
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作者：
韩晓
目的/假设转录因子FOXO 1（forkhead box O 1）诱导胰岛β细胞内质网应激，并参与脂肪酸诱导的胰岛素分泌缺陷，Caskis是FOXO 1的下游靶基因。使用棕榈酸诱导的胰岛素释放缺陷的INS-1细胞，我们调查FOXO 1和Cask.MethodsCa2 +/钙调素依赖性丝氨酸蛋白激酶（CASK）和FOXO 1的表达水平和位置之间的关系进行了评估通过实时PCR，免疫印迹和免疫荧光。使用染色质免疫沉淀（ChIP）和荧光素酶测定来检查FOXO 1对Cask的调节。钾刺激的胰岛素分泌试验用于验证INS-1细胞和胰岛的功能。使用电子显微镜来建立CASK敲除后胰岛素颗粒在胰岛中的锚定过程。结果棕榈酸降低CASK水平并增加FOXO 1水平。ChIP和荧光素酶分析表明FOXO 1与Cask启动子结合，棕榈酸酯处理增强了FOXO 1与Cask启动子的结合。在INS-1细胞和原代胰岛中，CASK敲低减少了胰岛素的释放，而CASK过表达逆转了棕榈酸诱导的胰岛素减少。CASK敲低减弱了forskolin增强的胰岛素释放，但CASK过表达并不改变硝苯地平诱导的胰岛素分泌抑制。在胰岛β细胞中，CASK敲低减少了胰岛素囊泡的锚定到cell membranes.Conclusions/interpretationThe诱导β细胞胰岛素分泌缺陷的脂肪酸介导，至少部分，通过FOXO 1下调ofCask表达。其主要特征是阻碍胰岛素颗粒锚定在β细胞膜上。
Aims/hypothesisThe transcription factor forkhead box O1 (FOXO1) induces pancreatic islet beta cell endoplasmic reticulum stress and is involved in fatty-acid-induced insulin-secretion defects.Caskis a downstream target gene of FOXO1. Using INS-1 cells with palmitate-induced insulin-release defects, we investigated the relationship between FOXO1 andCask.MethodsThe expression levels and location of calcium/calmodulin-dependent serine protein kinase (CASK) and FOXO1 were evaluated by real-time PCR, western blotting and immunofluorescence. The regulation ofCaskby FOXO1 was examined using chromatin immunoprecipitation (ChIP) and luciferase assays. Potassium-stimulated insulin-secretion assays were used to verify the function of INS-1 cells and islets. Electron microscopy was used to establish the anchoring process of the insulin granules after CASK knockdown in islets.ResultsPalmitic acid reduced CASK levels and increased FOXO1 levels. ChIP and luciferase assays demonstrated FOXO1 binding with theCaskpromoter, which was enhanced by palmitate treatment. CASK knockdown reduced insulin release in INS-1 cells and primary islets, andCaskoverexpression reversed the palmitate-induced insulin reduction. CASK knockdown attenuated forskolin-enhanced insulin release, butCaskoverexpression did not change the insulin-secretion suppression induced by nifedipine. In pancreatic islet beta cells, CASK knockdown reduced the anchoring of insulin vesicles to cell membranes.Conclusions/interpretationThe induction of beta cell insulin-secretion defects by fatty acids is mediated, at least in part, by FOXO1 via downregulation ofCaskexpression. It is characterised mainly as an obstruction of the anchoring of insulin granules to beta cell membranes.
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影响因子：
15.9
作者：
Kahn, BB;Flier, JS
通讯作者：
Flier, JS
DOI：
10.1007/978-1-59259-716-1_4
发表时间：
1999
期刊：
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影响因子：
--
作者：
J. Despres;A. Marette
通讯作者：
J. Despres;A. Marette
影响因子：
4.8
作者：
Suckow, Arthur T.;Comoletti, Davide;Chessler, Steven D.
通讯作者：
Chessler, Steven D.
影响因子：
7.7
作者：
Weir, GC;Laybutt, DR;Sharma, A
通讯作者：
Sharma, A
叉头盒 O1/胰腺和十二指肠同源盒 1 细胞内易位由 c-Jun N 末端激酶调节，并参与前列腺素 E2 诱导的胰腺 β 细胞功能障碍。
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