The Steroid Metabolome in the Isolated Ovarian Follicle and Its Response to Androgen Exposure and Antagonism.
The Steroid Metabolome in the Isolated Ovarian Follicle and Its Response to Androgen Exposure and Antagonism.
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DOI：
10.1210/en.2016-1851
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发表时间：
2017-05-01
期刊：
影响因子：
4.8
通讯作者：
Arlt W
中科院分区：
文献类型：
--
作者：
Lebbe M;Taylor AE;Visser JA;Kirkman-Brown JC;Woodruff TK;Arlt W
卵巢卵泡是激素生成的主要部位，对正常卵巢功能和女性生殖至关重要。我们对发育卵泡中雄激素合成和代谢的理解受到以前使用的检测方法的敏感性和特异性问题的限制。在这里，我们使用液相色谱-串联质谱法来绘制包封的体外卵泡生长系统中从小鼠次级卵泡到窦卵泡的阶段依赖性内源性类固醇代谢组。此外，在雄激素前体、非芳香化活性雄激素和雄激素受体（AR）拮抗剂的存在下培养卵泡，以评估对类固醇生成和卵泡发育的影响。培养的卵泡显示出内源性雄激素、雌激素和黄体酮产生的阶段依赖性增加，与性类固醇前体脱氢表雄酮孵育表明卵泡能够在发育早期活跃地合成雄激素。雄激素暴露和拮抗显示ar介导的对卵泡生长和腔形成的影响遵循双期模式，低水平雄激素诱导卵泡更快成熟，高剂量雄激素抑制卵母细胞成熟和卵泡生长。至关重要的是，我们的研究提供了卵泡内反馈回路调节类固醇生成的证据，外源雄激素暴露后卵泡雄激素合成减少，额外的AR拮抗剂治疗后雄激素输出增加。我们认为这种反馈回路有助于维持发育中的卵泡中雄激素暴露的平衡。在增加雄激素补充时观察到的卵泡生长和功能的双相反应对我们理解多囊卵巢综合征的病理生理学和雄激素在体外受精环境中的剂量依赖性效用具有重要意义。分离卵巢卵泡的类固醇代谢组质谱分析揭示了雄激素合成的早期发育能力，雄激素受体拮抗剂上调了雄激素合成的能力。
The ovarian follicle is a major site of steroidogenesis, crucially required for normal ovarian function and female reproduction. Our understanding of androgen synthesis and metabolism in the developing follicle has been limited by the sensitivity and specificity issues of previously used assays. Here we used liquid chromatography–tandem mass spectrometry to map the stage-dependent endogenous steroid metabolome in an encapsulated in vitro follicle growth system, from murine secondary through antral follicles. Furthermore, follicles were cultured in the presence of androgen precursors, nonaromatizable active androgen, and androgen receptor (AR) antagonists to assess effects on steroidogenesis and follicle development. Cultured follicles showed a stage-dependent increase in endogenous androgen, estrogen, and progesterone production, and incubations with the sex steroid precursor dehydroepiandrosterone revealed the follicle as capable of active androgen synthesis at early developmental stages. Androgen exposure and antagonism demonstrated AR–mediated effects on follicle growth and antrum formation that followed a biphasic pattern, with low levels of androgens inducing more rapid follicle maturation and high doses inhibiting oocyte maturation and follicle growth. Crucially, our study provides evidence for an intrafollicular feedback circuit regulating steroidogenesis, with decreased follicle androgen synthesis after exogenous androgen exposure and increased androgen output after additional AR antagonist treatment. We propose that this feedback circuit helps maintain an equilibrium of androgen exposure in the developing follicle. The observed biphasic response of follicle growth and function in increasing androgen supplementations has implications for our understanding of polycystic ovary syndrome pathophysiology and the dose-dependent utility of androgens in in vitro fertilization settings. Steroid metabolome analysis by mass spectrometry in the isolated ovarian follicle revealed early developmental capacity for androgen synthesis, which was upregulated by androgen receptor antagonists.