Steroidogenic enzyme and key decidualization marker dysregulation in endometrial stromal cells from women with versus without endometriosis.

Identification of mechanisms underlying endometriosis pathogenesis will facilitate understanding and treatment of infertility and pain associated with this disorder. Herein, we investigated the expression of steroidogenic pathway enzymes and key decidualization biomarkers in endometrial tissue and in eutopic endometrial stromal fibroblasts (hESFs) from women with vs. those without endometriosis, and subsequently treated in vitro with 8-bromo-cAMP (8-Br-cAMP) or progesterone (P4). Real-time quantitative PCR, immunohistochemistry, ELISA, and radiometric aromatase activity assay were used. The results demonstrate significantly increased (14.5-fold; P=0.037) expression of aromatase in eutopic endometrium of women with disease. In 8-Br-cAMP-treated hESF from eutopic endometrium of women with endometriosis, the balance in estradiol (E2) and P4 biosynthetic and metabolizing enzymes is disturbed (decreased HSD3B1 and HSD17B2, and increased HSD17B1 and aromatase), with the equilibrium being shifted towards an E2-enriched milieu. However, hESF from the same group of women treated with P4 did not demonstrate such responsiveness. Lower expression of IGFBP1 and prolactin mRNA and protein was observed in hESF from women with vs. those without endometriosis in response to 8-Br-cAMP, but not P4, suggesting a blunted response of these decidual biomarkers to activation of the PKA pathway in eutopic endometrium in women with disease. The dichotomy of 8-Br-cAMP regulation of select steroidogenic enzymes leading to an enriched E2 milieu within the endometrium and a blunted response of decidual biomarkers to this decidualizing agent of hESF from women with endometriosis suggests resistance to full decidualization of the stromal fibroblasts and mechanisms underlying implantation failure and the pathophysiology of this disorder.

Proliferation of ovarian theca-interstitial cells is modulated by antioxidants and oxidative stress.

BACKGROUND: Maintenance of ovarian homeostasis requires precise regulation of proliferation of thecal- interstitial (T-I) cells. Recent evidence indicates that oxidative stress and antioxidants modulate proliferation of various tissues under both physiological and pathological conditions. This study evaluated the effects of oxidative stress and antioxidants on T-I proliferation. METHODS: Rat T-I cells were cultured in serum-free medium and proliferation was assessed by determination of DNA synthesis using the thymidine incorporation assay, by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and by direct counting of steroidogenically active cells and steroidogenically inactive cells. RESULTS: Antioxidants and reactive oxygen scavengers induced a dose-dependent decrease of T-I proliferation. Vitamin E succinate was inhibitory at 10-100 micro mol/l, ebselen was inhibitory at 0.3-30 micro mol/l, and superoxide dismutase was inhibitory at 300-1000 IU/ml. In contrast, oxidative stress resulted in a biphasic effect. Modest oxidative stress induced by 1 mmol/l hypoxanthine and xanthine oxidase (3-30 micro U/ml) stimulated proliferation of T-I cells, while greater oxidative stress induced by xanthine oxidase (1 mU/ml) profoundly inhibited proliferation. Direct cell counting demonstrated comparable effects on steroidogenically active and inactive cells. CONCLUSIONS: Reactive oxygen species may play a role in the regulation of growth of ovarian mesenchyme. Under pathological conditions, such as those encountered in polycystic ovary syndrome, excessive oxidative stress and depletion of antioxidants may contribute to ovarian mesenchymal hyperplasia.