The Steroid Metabolome in the Isolated Ovarian Follicle and Its Response to Androgen Exposure and Antagonism.
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.
Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, United Kingdom.|Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.
Marie
M
Lebbe
Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, United Kingdom.
Angela E
AE
Taylor
Department of Internal Medicine, Erasmus MC, 3015 CN Rotterdam, The Netherlands.
Jenny A
JA
Visser
Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, United Kingdom.|Tommy's National Centre for Miscarriage Research, Birmingham Women's Hospital NHS Foundation Trust, Birmingham B15 2TH, United Kingdom.
Jackson C
JC
Kirkman-Brown
Division of Reproductive Science in Medicine, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611.
Teresa K
TK
Woodruff
Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, United Kingdom.|Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham B15 2TH, United Kingdom.
Wiebke
W
Arlt
D059002:Androgen Receptor Antagonists / Q000494:pharmacology*; D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D003687:Dehydroepiandrosterone / Q000378:metabolism; D005260:Female; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D055442:Metabolome / Q000187:drug effects*; D051379:Mice; D006080:Ovarian Follicle / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D013256:Steroids / Q000378:metabolism*
D059002:Androgen Receptor Antagonists; D000728:Androgens; D012739:Gonadal Steroid Hormones; D013256:Steroids; D003687:Dehydroepiandrosterone