DEHP和MEHP对H295R细胞类固醇激素合成基因表达的影响

Effects of DEHP and MEHP on the Expression of Steroidogenic Genes in the H295R Cells

为探讨邻苯二甲酸二(2-乙基己基)酯(di-(2-ethylhexyl)phthalate,DEHP)及其代谢产物邻苯二甲酸单-2-乙基己酯(mono-(2-ethylhexyl)phthalate,MEHP)对H295R细胞类固醇激素合成关键基因表达的影响,本实验将H295R细胞分别暴露于DEHP(0、1、10、100、1 000μmol·L-1)和MEHP(0、1、10、100、1 000μmol·L-1)24 h,用MTT法检测细胞活性,并应用荧光定量PCR法分析细胞类固醇激素合成过程中关键酶的基因表达水平。结果显示,1 000μmol·L-1DEHP和MEHP对H295R细胞染毒24 h显著降低H295R细胞活力,所以本研究采用了较低的染毒浓度(0、1、10和100μmol·L-1)对H295R细胞染毒24 h来评估DEHP和MEHP对H295R细胞类固醇激素合成通路的影响。1、10和100μmol·L-1DEHP显著增加醛固酮合成酶CYP11B2的基因表达水平。10μmol·L-1DEHP显著上调了3-β羟基类固醇脱氢酶(3β-HSD2)的基因表达水平。1、10和100μmol·L-1MEHP显著下调了3-β羟基类固醇脱氢酶(3β-HSD1和3β-HSD2)、17β羟基类固醇脱氢酶17β-HSD4、17α羟化酶/17,20裂解酶CYP17和芳香酶CYP19a的基因表达水平。10和100μmol·L-1MEHP染毒H295R 24 h显著下调了CYP21和STAR的基因表达水平,然而,10和100μmol·L-1MEHP显著上调了CYP11B2的基因表达水平。100μmol·L-1MEHP显著下调了17β-HSD1的基因表达水平。上述研究结果表明,DEHP、MEHP都可不同程度影响H295R细胞类固醇激素合成过程中关键基因的表达。MEHP可以通过抑制STAR基因的表达,从而将影响胆固醇在细胞内的转运;并能显著性抑制类固醇激素合成过程中CYP17、CYP19a、3β-HSD1、3β-HSD2、17β-HSD1、17β-HSD4、CYP21基因的表达,最终将抑制H295R细胞中类固醇激素的合成。与DEHP相比,MEHP对H295R细胞类固醇激素合成关键基因表达的影响较明显。

To study the effects of exposure to di（2-ethylhexyl） phthalate（DEHP） and its main metabolite mono（2-ethylhexyl） phthalate（MEHP） on the expression of steroidogenic genes in the H295 R cells, H295 R cells were exposed to DEHP（0, 1, 10, 100, 1 000 μmol·L-1） and MEHP（0, 1, 10, 100, 1 000 μmol·L-1） respectively for 24 h,cell viability was assessed by MTT assay, and real time quantitative PCR method was conducted to explore the m RNA expression levels of the key enzymes involved in steroid hormone synthesis. The results showed that 1 000μmol·L-1 DEHP or MEHP significantly reduced cell viability of H295 R cells. Therefore, the lower concentrations of DEHP and MEHP were selected to evaluate the effects of DEHP and MEHP on the steroid synthesis pathway of H295 R cells in the present study. The expression of aldosterone synthase（CYP11 B2） was upregulated significantly upon DEHP at different dose compared to that of the control. Moreover, the transcript level of 3-beta hydroxy steroid dehydrogenase（3β-HSD2） was also increased significantly during exposure to 10 μmol·L-1 DEHP. In contrast,The m RNA levels of 3β-HSD1, 3β-HSD2, 17β-hydroxy steroid dehydrogenase（17β-HSD4）, P450 17 alphahydroxylase/C17-20-lyase gene（Cyp17） and aromatic enzyme（CYP19 a） were significantly decreased in H295 R cells after exposure to 1, 10 and 100 μmol·L-1 MEHP. Exposure to MEHP of 10 and 100 μmol·L-1 for 24 h significantly down-regulated the m RNA levels of CYP21 and STAR and up-regulated the expression of CYP11 B2 in H295 R cells. 100 μmol·L-1 MEHP significantly down-regulated the expression levels of 17β-HSD1. Thus, DEHP and MEHP can affect the expression of key genes involved in steroid synthesis in H295 R cells to a certain extent.MEHP can inhibit the expression of STAR gene and affect the transport of steroid hormone in cells, then significantly inhibit the expression of CYP17, CYP19 a, 3β-HSD1, 3β-HSD2, 17β-HSD1, 17β-HSD4, CYP21, which were all involved in steroid hormone biosynthesis, and ultimately inhibit the synthesis of steroid hormones in H295 R cells. The effects of MEHP on the expression of steroidogenic genes in the H295 R cells were more obvious than that of DEHP.