Pioglitazone inhibits androgen production in NCI-H295R cells by regulating gene expression of CYP17 and HSD3B2
Pioglitazone inhibits androgen production in NCI-H295R cells by regulating gene expression of CYP17 and HSD3B2
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DOI：
10.1124/mol.106.028902
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发表时间：
2007-03-01
影响因子：
3.6
通讯作者：
Flueck, Christa E.
中科院分区：
文献类型：
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作者：
Kempna, Petra;Hofer, Gaby;Flueck, Christa E.
吡格列酮、罗格列酮等噻唑烷二酮类药物被广泛用于2型糖尿病的胰岛素增敏剂治疗。在患有多囊卵巢综合征的糖尿病妇女中，使用吡格列酮或罗格列酮治疗可以改善胰岛素抵抗和高雄激素血症，但TZDS下调雄激素产生的机制尚不清楚。雄激素在人类的性腺和肾上腺中合成。我们通过分析吡格列酮和罗格列酮对人肾上腺NCI-H295R细胞类固醇合成的影响，研究了雄激素产生的调节。两种TZD均改变了NCI-H295R细胞的类固醇水平，并抑制雄激素生物合成关键酶P450c17和3βHSDII的活性。吡格列酮可抑制细胞色素P17和HSD3B2基因的表达，而罗格列酮无此作用。同样，在NCI-H295R细胞中，吡格列酮抑制基础和8溴cAMP刺激的CYP17和HSD3B2启动子的活性。然而，吡格列酮并没有改变cAMP反应荧光素酶的活性，表明它不影响cAMP/蛋白激酶A/cAMP反应元件结合蛋白通路的信号转导。尽管PPAR-γ是TZDS的核受体，但用小干扰RNA技术抑制PPAR-γ并不改变吡格列酮对细胞色素P17和HSD3B2表达的抑制作用，提示吡格列酮的作用不依赖于PPAR-γ。另一方面，用丝裂原活化蛋白激酶(MEK)/细胞外信号调节激酶(ERK)抑制剂2-(2-氨基-3-甲氧基苯基)-4H-1-苯并吡喃-4-酮(PD98059)处理NCI-H295R细胞，可增强其启动子活性和细胞色素P17的表达。这种作用被吡格列酮逆转，表明MEK/ERK信号通路参与了吡格列酮对雄激素生物合成的调节。
Thiazolidinediones (TZDs) such as pioglitazone and rosiglitazone are widely used as insulin sensitizers in the treatment of type 2 diabetes. In diabetic women with polycystic ovary syndrome, treatment with pioglitazone or rosiglitazone improves insulin resistance and hyperandrogenism, but the mechanism by which TZDs down-regulate androgen production is unknown. Androgens are synthesized in the human gonads as well as the adrenals. We studied the regulation of androgen production by analyzing the effect of pioglitazone and rosiglitazone on steroidogenesis in human adrenal NCI-H295R cells, an established in vitro model of steroidogenesis of the human adrenal cortex. Both TZDs changed the steroid profile of the NCI-H295R cells and inhibited the activities of P450c17 and 3 beta HSDII, key enzymes of androgen biosynthesis. Pioglitazone but not rosiglitazone inhibited the expression of the CYP17 and HSD3B2 genes. Likewise, pioglitazone repressed basal and 8-bromo-cAMP-stimulated activities of CYP17 and HSD3B2 promoter reporters in NCI-H295R cells. However, pioglitazone did not change the activity of a cAMP-responsive luciferase reporter, indicating that it does not influence cAMP/protein kinase A/cAMP response element-binding protein pathway signaling. Although peroxisome proliferator-activated receptor gamma (PPAR gamma) is the nuclear receptor for TZDs, suppression of PPAR gamma by small interfering RNA technique did not alter the inhibitory effect of pioglitazone on CYP17 and HSD3B2 expression, suggesting that the action of pioglitazone is independent of PPAR gamma. On the other hand, treatment of NCI-H295R cells with mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitor 2-(2-amino-3-methoxyphenyl)-4H- 1-benzopyran-4-one (PD98059) enhanced promoter activity and expression of CYP17. This effect was reversed by pioglitazone treatment, indicating that the MEK/ERK signaling pathway plays a role in regulating androgen biosynthesis by pioglitazone.