AA-CYP表氧化酶代谢产物对胰岛β细胞增殖和细胞周期的影响

Effects of AA-CYP Epi-oxidase Metabolites on Proliferation and Cell Cycle of Pancreatic β Cells

花生四烯酸(AA)经过细胞色素P450(CYP)表氧化酶途径生成环氧二十碳三烯酸(EETs)和20-羟基二十碳四烯酸(20-HETE)。为探讨EETs和20-HETE对胰岛β细胞增殖和细胞周期的影响及其机制,本试验将培养的MIN6小鼠胰岛β细胞分为空白对照组和不同浓度EETs和20-HETE处理组,分别采用CCK-8法、流式细胞术和Western blot法检测EETs和20-HETE对胰岛β细胞增殖和细胞周期的影响。CCK-8法结果显示,14,15-EET促进胰岛β细胞增殖,且在一定范围内呈时间和浓度依赖性;流式细胞术结果显示,EETs作用后G1期细胞减少,S期和G2/M期细胞增多,从而促进胰岛β细胞的增殖;Western blot试验结果显示,11,12-EET和14,15-EET能够激活AKT磷酸化水平及PI3K活化状况。本试验结果表明,EETs和20-HETE联合使用时,对胰岛β细胞的增殖没有促进作用,但EETs能够促进小鼠胰岛β细胞增殖,其分子机制可能是EETs激活了PI3K/AKT信号转导通路。

Arachidonic acid(AA) produces epoxyeicosatrienoic acids(EETs) and 20-hydroxy eicosatetraenoic acid(20-HETE) via cytochrome P450(CYP) epi-oxidase pathway. To determine the effect and mechanism of the EETs and 20-HETE on cell proliferation and cell cycle of pancreatic β cells, this study divided cultured murine MIN6 β cells into different concentrations of EETs and 20-HETE groups and normal control group. CCK-8 analysis, flow cytometry and Western blot were used respectively to detect cell proliferation and cell cycle. CCK-8 analysis showed that 14,15-EET increased β cells proliferation, and exhibited time dependent and concentration dependent mode;flow cytometry results showed that after EETs treatment, the proportion of cells in G1phase was decreased, while the proportions of cells in S and G2/M phase were increased, which promoted the proliferation of pancreatic β cells;Western blot result showed that 11,12-EET and 14,15-EET promoted the phosphorylation level of AKT and the activation of PI3 K/AKT signaling pathways. Thus, although combination of EETs and 20-HETE has no promotive effect on the proliferation of pancreatic β cells, EETs alone significantly promote the proliferation of murine pancreatic β cells through the activation of PI3 K/AKT signaling pathways.