Long-term pancreatic beta cell exposure to high levels of glucose but not palmitate induces DNA methylation within the insulin gene promoter and represses transcriptional activity.
Long-term pancreatic beta cell exposure to high levels of glucose but not palmitate induces DNA methylation within the insulin gene promoter and represses transcriptional activity.
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胰腺β细胞长期暴露于高水平的葡萄糖而非棕榈酸中，会诱导胰岛素基因启动子内的DNA甲基化并抑制转录活性。
DOI：
10.1371/journal.pone.0115350
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Oiso Y
中科院分区：
文献类型：
--
作者：
Ishikawa K;Tsunekawa S;Ikeniwa M;Izumoto T;Iida A;Ogata H;Uenishi E;Seino Y;Ozaki N;Sugimura Y;Hamada Y;Kuroda A;Shinjo K;Kondo Y;Oiso Y
最近的研究表明表观遗传学与糖尿病的病理生理学有关。此外，胰岛素启动子，特别是cAMP反应元件的DNA甲基化在糖尿病患者中增加，其不可逆地使基因转录失活。然而，其潜在机制仍不清楚。我们的目的是研究胰岛素启动子DNA甲基化在营养过剩状态。INS-1细胞（大鼠胰腺β细胞系）在正常培养葡萄糖（11.2 mmol/l）或实验高葡萄糖（22.4 mmol/l）条件下培养14天，含或不含0.4 mmol/l棕榈酸。采用亚硫酸氢盐测序和焦磷酸测序技术对大鼠胰岛素1基因（Ins 1）启动子区的DNA甲基化进行了研究。实验高葡萄糖条件下显着抑制胰岛素mRNA和增加DNA甲基化在所有5个CpG位点内的Ins 1启动子，包括cAMP反应元件，在时间依赖性和葡萄糖浓度依赖性的方式。在实验高葡萄糖条件下的DNA甲基化是独特的Ins 1启动子，然而，棕榈酸并不影响DNA甲基化。人工甲基化Ins 1启动子显着抑制启动子驱动的荧光素酶活性，和DNA甲基化抑制剂显着改善胰岛素mRNA抑制实验高糖条件。实验高葡萄糖条件下显着增加DNA甲基转移酶的活性和降低10 - 11易位甲基胞嘧啶双加氧酶的活性。氧化应激和内质网应激不影响Ins 1启动子的DNA甲基化。高葡萄糖，但不是棕榈酸增加异位三酰甘油积累平行于DNA甲基化。二甲双胍上调胰岛素基因表达，抑制DNA甲基化和异位三酰甘油积累。最后，从Zucker糖尿病肥胖大鼠分离的胰岛中Ins 1启动子的DNA甲基化增加。这项研究有助于阐明过度营养状态对胰腺β细胞中Ins 1启动子DNA甲基化的影响。它为糖尿病的不可逆病理生理学提供了新的见解。
Recent studies have implicated epigenetics in the pathophysiology of diabetes. Furthermore, DNA methylation, which irreversibly deactivates gene transcription, of the insulin promoter, particularly the cAMP response element, is increased in diabetes patients. However, the underlying mechanism remains unclear. We aimed to investigate insulin promoter DNA methylation in an over-nutrition state. INS-1 cells, the rat pancreatic beta cell line, were cultured under normal-culture-glucose (11.2 mmol/l) or experimental-high-glucose (22.4 mmol/l) conditions for 14 days, with or without 0.4 mmol/l palmitate. DNA methylation of the rat insulin 1 gene (Ins1) promoter was investigated using bisulfite sequencing and pyrosequencing analysis. Experimental-high-glucose conditions significantly suppressed insulin mRNA and increased DNA methylation at all five CpG sites within the Ins1 promoter, including the cAMP response element, in a time-dependent and glucose concentration-dependent manner. DNA methylation under experimental-high-glucose conditions was unique to the Ins1 promoter; however, palmitate did not affect DNA methylation. Artificial methylation of Ins1 promoter significantly suppressed promoter-driven luciferase activity, and a DNA methylation inhibitor significantly improved insulin mRNA suppression by experimental-high-glucose conditions. Experimental-high-glucose conditions significantly increased DNA methyltransferase activity and decreased ten-eleven-translocation methylcytosine dioxygenase activity. Oxidative stress and endoplasmic reticulum stress did not affect DNA methylation of the Ins1 promoter. High glucose but not palmitate increased ectopic triacylglycerol accumulation parallel to DNA methylation. Metformin upregulated insulin gene expression and suppressed DNA methylation and ectopic triacylglycerol accumulation. Finally, DNA methylation of the Ins1 promoter increased in isolated islets from Zucker diabetic fatty rats. This study helps to clarify the effect of an over-nutrition state on DNA methylation of the Ins1 promoter in pancreatic beta cells. It provides new insights into the irreversible pathophysiology of diabetes.
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影响因子：
7.7
作者：
Kawamori, D;Kajimoto, Y;Hori, M
通讯作者：
Hori, M
影响因子：
2.7
作者：
Colella, S;Shen, L;Krahe, R
通讯作者：
Krahe, R
影响因子：
158.5
作者：
Holman, Rury R.;Paul, Sanjoy K.;Neil, H. Andrew W.
通讯作者：
Neil, H. Andrew W.
影响因子：
4.5
作者：
Dayeh T;Volkov P;Salö S;Hall E;Nilsson E;Olsson AH;Kirkpatrick CL;Wollheim CB;Eliasson L;Rönn T;Bacos K;Ling C
通讯作者：
Ling C
影响因子：
1.9
作者：
Donkena KV;Young CY;Tindall DJ
通讯作者：
Tindall DJ