The effect of estradiol on granulosa cell responses to FSH in women with polycystic ovary syndrome.

BACKGROUND: The influence of estradiol (E2) on granulosa cell (GC) function has not been tested clinically in women with polycystic ovary syndrome (PCOS). The objective of this study is to determine if E2 influences GC responses to FSH in women with PCOS. METHODS: This is a two phase, single cohort study conducted over a 2-year period at a single academic center. Nine women with PCOS according to NIH criteria. In Phase 1, FSH stimulation of GC responses as measured by E2 and Inhibin B (Inh B) were assessed before and at 5 and 6 weeks after GnRH agonist administration. In Phase 2, the same protocol was employed with the addition of an aromatase inhibitor (letrozole, LET) administered daily beginning at week 4 for 2 weeks. RESULTS: In Phase 1, recovery of FSH, E2 and Inh B from ovarian suppression occurred at 5 and 6 weeks after GnRH agonist injection and preceded resumption of LH and androgen secretion. In Phase 2, hormone recovery after GnRH agonist was characterized by elevated FSH and suppressed E2 levels whereas recovery of LH and androgen levels were unchanged. In Phase 1, FSH stimulated E2 and Inh B responses were unaltered during recovery from ovarian suppression. In Phase 2, E2 and Inh B fold changes after FSH were significantly reduced at weeks 5 (p < 0.04) and 6 (p < 0.01), respectively. CONCLUSION: In anovulatory women with PCOS, chronic, unopposed E2 secretion may contribute, at least in part, to enhanced ovarian responsiveness to FSH. TRIAL REGISTRATION: NCT02389088.

Comparison of inhibin B and estradiol responses to intravenous FSH in women with polycystic ovary syndrome and normal women.

BACKGROUND: Inhibin B (Inh B) is produced by pre-antral and early antral follicles whereas estradiol (E(2)) is a product of follicles undergoing antrum formation. This temporal distinction is evident in the patterns of Inh B and E(2) release earlier and later during the follicular phase of the menstrual cycle, respectively. However, in previous studies of women with polycystic ovary syndrome (PCOS) and normal controls, release of these granulosa cell (GC) products appears to be simultaneous in response to FSH stimulation. In order to reconcile these disparate findings, we conducted dose-response studies in both PCOS women and normal controls to determine whether GC product responses were due to the amount of FSH administered. In addition, we compared FSH-stimulated responses in PCOS women at various stages of recovery following ovarian suppression with a long-acting GnRH agonist to examine whether Inh B and E(2) responses reflected the level of ovarian follicle activity (i.e. circulating E(2) levels). METHODS: Women with PCOS, 18-35 years (n = 23), and normal ovulatory controls, 18-35 years (n = 10) were recruited for study. Dose-responses were assessed over 24 h following intravenous administration of 0 (saline), 37.5, 75 and 150 IU of recombinant human FSH (r-hFSH) in PCOS and normal women. In addition, E(2) and Inh B responses to 150 IU of r-hFSH were assessed at baseline and 4, 6 and 8 weeks following suppression of ovarian steroidogenesis by a long-acting GnRH agonist in PCOS women. RESULTS: In PCOS women and normal controls, serum Inh B and E(2) exhibit similar and simultaneous dose-responsiveness to FSH stimulation. During recovery from ovarian suppression, basal and stimulated Inh B release appear to be restored earlier than that of E(2) in PCOS women. CONCLUSIONS: These findings are consistent with the notion that, in PCOS women, the level of ovarian follicle activity largely determines the earlier release of Inh B compared with E(2).

Lack of Serum anti-Mullerian hormone responses after recombinant human chorionic gonadotropin stimulation in women with polycystic ovary syndrome.

CONTEXT: Polycystic ovary syndrome (PCOS) is an anovulatory disorder characterized by excess androgen production and increased LH secretion. Serum anti-Mullerian hormone (AMH) is also elevated in this disorder. Women with PCOS exhibit a positive correlation between AMH and LH levels and recent in vitro data demonstrate that LH can directly stimulate AMH production by granulosa cells from women with PCOS. OBJECTIVE: The objective of the study was to directly test whether LH increases AMH production in women with PCOS in vivo by assessing responses after recombinant human chorionic gonadotropin (r-hCG) stimulation. DESIGN: This was a prospective study. SETTING: The study was conducted at a research center at an academic medical center. PARTICIPANTS: Women with PCOS (n = 28) and normal controls (n = 29) participated in the study. INTERVENTIONS: Blood samples were obtained before and 24 hours after iv administration of 25 µg r-hCG. MAIN OUTCOME MEASURES: Basal and stimulated serum AMH, androstenedione, T, and 17-hydroxyprogesterone levels were measured. RESULTS: Baseline AMH levels in women with PCOS were greater than in normal controls and correlated with levels of LH as well as androstenedione, T, and 17-hydroxyprogesterone. A rise of serum AMH levels was not observed after r-hCG administration in women with PCOS or normal ovaries. CONCLUSION: These findings are in contrast to in vitro evidence demonstrating that AMH secretion by granulosa cells of PCOS women in response to LH stimulation and suggest AMH regulation in vivo is complex and that the elevated serum AMH in women with PCOS is not a direct effect of the excess LH production characteristic of PCOS.

Decreased inhibin B responses following recombinant human chorionic gonadotropin administration in normal women and women with polycystic ovary syndrome.

OBJECTIVE: To determine whether granulosa cells contribute to excess androgen production, by assessing inhibin B (Inh B) responses to hCG in women with polycystic ovary syndrome (PCOS) and in normal women. DESIGN: Prospective study. SETTING: Academic medical center. PATIENT(S): Twenty women with PCOS and 16 normal women. INTERVENTION(S): Blood samples obtained before and 24 hours after injection of 25 µg recombinant hCG (r-hCG). MAIN OUTCOME MEASURE(S): Basal and stimulated Inh B, E2, androstenedione (A), and T responses after r-hCG administration. RESULT(S): In normal and PCOS women, r-hCG induced a significant reduction of Inh B levels. Lowered Inh B responses were not related to body mass index, PCOS status, or age by multivariate regression. Recombinant hCG significantly increased serum A and E2 in both normal and PCOS women. CONCLUSION(S): In normal and PCOS women, Inh B production was decreased following r-hCG administration. These findings strongly suggest that in PCOS women androgen excess is not enhanced by LH-stimulated Inh B production. CLINICAL TRIAL REGISTRATION NUMBER: NCT00747617.

Distinct developmental signatures of human abdominal and gluteal subcutaneous adipose tissue depots.

CONTEXT: Fat distribution differs in men and women, but in both sexes, a predominantly gluteal-femoral compared with abdominal (central) fat distribution is associated with lower metabolic risk. Differences in cellular characteristics and metabolic functions of these depots have been described, but the molecular mechanisms involved are not understood. OBJECTIVE: Our objective was to identify depot- and sex-dependent differences in gene expression in human abdominal and gluteal sc adipose tissues. DESIGN AND METHODS: Abdominal and gluteal adipose tissue aspirates were obtained from 14 premenopausal women [age 27.5 ± 7.0 yr, body mass index (BMI) 27.3 ± 6.2 kg/m(2), and waist-to-hip ratio 0.82 ± 0.04] and 21 men (age 29.7±7.4 yr, BMI 27.2 ± 4.5 kg/m(2), and waist-to-hip ratio 0.91 ± 0.07) and transcriptomes were analyzed using Illumina microarrays. Expression of selected genes was determined in isolated adipocytes and stromal vascular fractions from each depot, and in in vitro cultures before and after adipogenic differentiation. RESULTS: A total of 284 genes were differentially expressed between the abdominal and gluteal depot, either specifically in males (n = 66) or females (n = 159) or in both sexes (n = 59). Most notably, gene ontology and pathway analysis identified homeobox genes (HOXA2, HOXA3, HOXA4, HOXA5, HOXA9, HOXB7, HOXB8, HOXC8, and IRX2) that were down-regulated in the gluteal depot in both sexes (P = 2 × 10(-10)). Conversely, HOXA10 was up-regulated in gluteal tissue and HOXC13 was detected exclusively in this depot. These differences were independent of BMI, were present in both adipocytes and stromal vascular fractions of adipose tissue, and were retained throughout in vitro differentiation. CONCLUSIONS: We conclude that developmentally programmed differences may contribute to the distinct phenotypic characteristics of peripheral fat.

Clinical evidence for predominance of delta-5 steroid production in women with polycystic ovary syndrome.

CONTEXT: In women with polycystic ovary syndrome (PCOS), the basis for ovarian androgen overproduction involves an overall increase of steroidogenesis, notably in the delta-4 pathway. However, in vitro studies have suggested that excessive androgen production occurs predominantly through the delta-5 pathway. OBJECTIVE: This study was performed to assess androgen dose-responses after human chorionic gonadotropin (hCG) stimulation in PCOS and normal women. DESIGN: We conducted a prospective study to compare androgen production after iv hCG in PCOS and normal women. SETTING: The study was conducted in a General Clinical Research Center in an academic medical center. PARTICIPANTS: Women with PCOS (age, 18-37 yr; n = 10) and normal ovulatory controls (age, 18-37 yr; n = 11) were recruited. INTERVENTIONS: For dose-response studies, blood samples were obtained before and at 0.5, 24, and 48 h after iv recombinant hCG (1, 10, 25, 100, and 250 µg). A subset of subjects underwent frequent blood sampling over 24 h after iv injection of 25 µg of recombinant hCG. MAIN OUTCOME MEASURE(S): We measured basal and stimulated serum 17-hydroxyprogesterone (17-OHP), androstenedione (A), testosterone (T), dehydroepiandrosterone, estradiol, and progesterone responses after hCG administration. RESULTS: In PCOS women, maximal A and T production was observed at the lowest doses of hCG, whereas responses were minimal in normal women. Incremental responses of 17-OHP, estradiol, and progesterone were greater in PCOS compared to normal women. CONCLUSION: In PCOS women, maximal A and T responses to hCG relative to those of 17-OHP are consistent with ovarian androgen overproduction via the delta-5 pathway.