Atorvastatin inhibits insulin synthesis by inhibiting the Ras/Raf/ERK/CREB pathway in INS-1 cells.
Atorvastatin inhibits insulin synthesis by inhibiting the Ras/Raf/ERK/CREB pathway in INS-1 cells.
复制标题
阿托伐他汀通过抑制 INS-1 细胞中的 Ras/Raf/ERK/CREB 通路来抑制胰岛素合成
DOI：
10.1097/md.0000000000004906
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发表时间：
2016-09
期刊：
影响因子：
1.6
通讯作者：
Chang B
中科院分区：
文献类型：
--
作者：
Sun H;Li Y;Sun B;Hou N;Yang J;Zheng M;Xu J;Wang J;Zhang Y;Zeng X;Shan C;Chang B;Chen L;Chang B
背景：2型糖尿病已成为一种全球性流行病。阿托伐他汀已成为预防和治疗动脉粥样硬化的基石。然而，越来越多的证据表明，他汀类药物可以剂量依赖性地增加糖尿病的风险。其机制尚不清楚。目的：Ras复合物途径（Ras/Raf/细胞外信号调节激酶[ERK]/cAMP反应元件结合蛋白[CREB]）是调节基因转录的主要途径。他汀类药物除了通过抑制3-羟基-3-甲基戊二酰辅酶A（HMG-COA）还原酶来抑制胆固醇合成外，还可以下调包括Ras复合物通路关键蛋白在内的一系列下游底物的磷酸化，从而抑制胰岛β细胞的胰岛素合成。本研究探讨了阿托伐他汀对大鼠胰岛胰岛素合成的抑制作用及其机制。方法：从Wistar大鼠分离胰岛，并在Roswell Park Memorial Institute（RPMI）-1640培养基中培养。用放射免疫法测定50 M阿托伐他汀处理前后培养液中胰岛素的含量。 采用实时定量聚合酶链反应检测阿托伐他汀对胰岛β细胞胰岛素信使核糖核酸（mRNA）表达的影响。Western blotting法检测Ras复合物通路（Ras/Raf/ERK/CREB）在阿托伐他汀抑制胰岛素合成中的作用。染色质免疫沉淀法检测阿托伐他汀对INS-1细胞核转录因子p-CREB与CRE结合的影响。结果：与对照组相比，阿托伐他汀治疗后24小时胰岛素水平下降了27.1%。阿托伐他汀通过降低胰岛β细胞胰岛素mRNA表达抑制胰岛素合成。50 M阿托伐他汀在体外INS-1细胞中抑制Ras复合物途径中Ras、Raf-1和p-CREB的活性。 此外，50 M阿托伐他汀在体外降低INS-1细胞中p-CREB与脱氧核糖核酸（DNA）的结合。 结论：阿托伐他汀通过抑制Ras复合物途径抑制β细胞胰岛素合成。
Backround:Type 2 diabetes has become a global epidemic disease. Atorvastatin has become a cornerstone in the prevention and treatment of atherosclerosis. However, increasing evidence showed that statins can dose-dependently increase the risk of diabetes mellitus. The mechanism is not clear. Objective:The Ras complex pathway (Ras/Raf/extracellular signal-regulated kinase [ERK]/cAMP response element-binding protein [CREB]) is the major pathway that regulates the gene transcription. Except for the inhibition of cholesterol synthesis by inhibiting the 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-COA) reductase, statins can also downregulate the phosphorylation of a series of downstream substrates including the key proteins of the Ras complex pathway, therefore may inhibit the insulin syntheses in pancreatic beta cells. In our study, we investigated the inhibitory effect and the underlying mechanism of atorvastatin on insulin synthesis in rat islets. Methods:Islets were isolated from Wistar rats and cultured in Roswell Park Memorial Institute (RPMI)-1640 medium. The insulin content in the medium was measured by radioimmunoassay before and after the treatment of 50 &mgr;M atorvastatin. Effect of atorvastatin on the expression of insulin message Ribonucleic acid (mRNA) in pancreatic islet beta cells was also detected using quantitative real-time polymerase chain reaction. Western blotting was used to explore the possible role of the Ras complex pathway (Ras/Raf/ERK/CREB) in atorvastatin-inhibited insulin synthesis. The effects of atorvastatin on the binding of nuclear transcription factor p-CREB with CRE in INS-1 cells were examined via chromatin immunoprecipitation assay. Results:Compared with the control group, the insulin level decreased by 27.1% at 24 hours after atorvastatin treatment. Atorvastatin inhibited insulin synthesis by decreasing insulin mRNA expression of pancreatic islet beta cells. The activities of Ras, Raf-1, and p-CREB in the Ras complex pathway were inhibited by 50 &mgr;M atorvastatin in INS-1 cells in vitro. Moreover, 50 &mgr;M atorvastatin reduced the binding of p-CREB with deoxyribonucleic acid (DNA) in INS-1 cells in vitro. Conclusion:Atorvastatin inhibits insulin synthesis in beta cells by inhibiting the activation of the Ras complex pathway.