Endometriosis and menopause-management strategies based on clinical scenarios.

Endometriosis is largely considered a premenopausal disease with symptoms often improving during menopausal transition. However, 2%-4% of postmenopausal women are affected by endometriosis symptoms. At the same time, many peri- and postmenopausal women experience menopausal symptoms and inquire about treatment. Because of the estrogen-dependent nature of endometriosis, treatment with menopausal hormone therapy requires careful assessment of the patient but should nevertheless be considered. Recurrence of endometriosis symptoms and risk for malignant transformation are potential risks to weigh when prescribing menopausal hormonal therapy. Choice of treatment should be guided by the presence and severity of current endometriosis symptoms, nature of menopausal symptoms, risk assessment of potential contraindications for treatment in patient history, and preferences of the woman after an informative discussion. Recurrence of endometriosis symptoms in a postmenopausal patient should always prompt rigorous evaluation, both in the presence and absence of hormonal treatment. Many recommendations on the topic are based on expert opinion and new studies are urgently needed to obtain evidence for optimal patient care.

Interaction between insulin and androgen signalling in decidualization, cell migration and trophoblast invasion in vitro.

Finely tuned decidualization of endometrial stromal fibroblasts into decidual cells is crucial for successful implantation and a healthy pregnancy. Both insulin and androgens are known to modulate decidualization, however, their complex effect on this process has not been fully elucidated. As hyperinsulinemia and hyperandrogenism are associated in clinical conditions, we aimed to investigate the interaction between insulin and androgens on decidualization. Primary human endometrial stromal cells were decidualized in vitro in the presence of insulin and/or androgens (dihydrotestosterone (DHT), testosterone). Gene or protein expressions of decidualization markers were measured, and cells size characteristics were determined. Migration of decidualizing endometrial stromal cells and invasion of HTR-8/SVneo trophoblast spheroids were assessed. We found that insulin and androgens in combination enhanced the upregulation of several decidualization markers including prolactin, tissue factor, tissue inhibitor of matrix metalloproteinase 3 and connexin-43, and also interacted in modulating cell size characteristics resulting in enlarged decidualizing cells. However, insulin and DHT together restricted the migration of decidualizing cells and invasion of trophoblast spheroids. Our findings suggest that insulin and androgens interact to potentiate the process of decidualization. On the other hand, inhibited cell migration and trophoblast invasion might negatively impact the function of decidualizing endometrial stromal cells.

Insulin regulation of solute carrier family 2 member 1 (glucose transporter 1) expression and glucose uptake in decidualizing human endometrial stromal cells: an in vitro study.

BACKGROUND: Solute carrier family 2 member 1 (SLC2A1; previously known as glucose transporter 1), is the most abundant glucose transporter in human endometrium and is up-regulated during decidualization, whereas high insulin may have a negative impact on this process. The present study aimed to investigate the effect of insulin on the expression of SLC2A1 and glucose uptake in decidualizing human endometrial stromal cells. METHODS: We induced in vitro decidualization of endometrial stromal cells obtained from regularly menstruating healthy non-obese women. The cells were treated with increasing concentrations of insulin, and the involvement of the transcription factor forkhead box O1 (FOXO1) was evaluated using a FOXO1 inhibitor. SLC2A1 mRNA levels were measured by Real-Time PCR and protein levels were evaluated by immunocytochemistry. Glucose uptake was estimated by an assay quantifying the cellular uptake of radioactive glucose. One-way ANOVA, Dunnett's multiple comparisons test and paired t-test were used to determine the statistical significance of the results. RESULTS: We found that insulin dose-dependently decreased SLC2A1 mRNA levels and decreased protein levels of SLC2A1 in decidualizing human endometrial stromal cells. Transcriptional inactivation of FOXO1 seems to explain at least partly the down-regulation of SLC2A1 by insulin. Glucose uptake increased upon decidualization, whereas insulin treatment resulted in a slight inhibition of the glucose uptake, although not significant for all insulin concentrations. CONCLUSIONS: These results indicate an impairment of decidualization by high concentrations of insulin. Future studies will determine the clinical significance of our results for endometrial function and decidualization in women with insulin resistance and hyperinsulinemia.

Improved menstrual function in obese women with polycystic ovary syndrome after behavioural modification intervention-A randomized controlled trial.

OBJECTIVE: Lifestyle intervention is the recommended first-line treatment for overweight women with polycystic ovary syndrome (PCOS). However, the efficacy of lifestyle change in improving reproductive function is still unclear. DESIGN: A randomized controlled trial (RCT) with allocation to a behavioural modification programme (intervention) or minimal intervention (control) for 4 months with a follow-up at 12 months. PATIENTS: Sixty-eight women, aged 18-40 years, body mass index (BMI) ≥ 27 kg/m2 , fulfilling all Rotterdam PCOS criteria were randomized to treatment. MEASUREMENTS: The primary outcome was improved menstrual regularity. Secondary outcomes were ovulation and pregnancy rates. RESULTS: At 4 months, the weight loss was significant in the intervention group (-2.1%, P = 0.002) and nonsignificant in the control group (-1.0%). A higher proportion of patients in the intervention group improved menstrual regularity compared to the control group, mean difference 35% (95% CI: 16-60), P = 0.003. There was no difference in ovulation rate between groups. Logistic regression analysis showed that intervention was the only predictor of improved menstrual function, OR 3.9 (95% CI: 1.3-11.9). At 12 months, a total of 54% of the women improved menstrual regularity compared to baseline (P = 0.000) and 43% (P = 0.000) had confirmed ovulation. 38% of the women wishing to become pregnant succeeded within 1 year of study completion. CONCLUSIONS: This is the first RCT in overweight women with PCOS showing efficacy in improving reproductive function following behavioural modification intervention in comparison with minimal intervention. Although extensive weight loss is difficult to achieve in these women, behavioural modification intervention can help improve reproductive function.

Prokineticin 1 is up-regulated by insulin in decidualizing human endometrial stromal cells.

Prokineticin 1 (PROK1), a hypoxia-regulated angiogenic factor, has emerged as a crucial regulator of embryo implantation and placentation. Dysregulation of PROK1 has been linked to recurrent pregnancy loss, pre-eclampsia, foetal growth restriction and preterm birth. These pregnancy complications are common in women with obesity and polycystic ovary syndrome, i.e. conditions associated with insulin resistance and compensatory hyperinsulinaemia. We investigated the effect of insulin on PROK1 expression during in vitro decidualization. Endometrial stromal cells were isolated from six healthy, regularly menstruating women and decidualized in vitro. Insulin induced a significant dose-dependent up-regulation of PROK1 on both mRNA and protein level in decidualizing endometrial stromal cells. This up-regulation was mediated by hypoxia-inducible factor 1-alpha (HIF1α) via the phosphatidylinositol 3-kinase (PI3K) pathway. Furthermore, we demonstrated that PROK1 did not affect the viability, but significantly inhibited the migration of endometrial stromal cells and the migratory and invasive capacity of trophoblast cell lines. This in vitro study provides new insights into the regulation of PROK1 by insulin in human decidualizing endometrial stromal cells, the action of PROK1 on migration of endometrial stromal cells, as well as migration and invasion of trophoblasts. We speculate that hyperinsulinaemia may be involved in the mechanisms by which PROK1 is linked to placenta-related pregnancy complications.

Dysregulation of In Vitro Decidualization of Human Endometrial Stromal Cells by Insulin via Transcriptional Inhibition of Forkhead Box Protein O1.

Insulin resistance and compensatory hyperinsulinemia are characteristic features of obesity and polycystic ovary syndrome, and both are associated with reduced fertility and implantation. There is little knowledge about the effect of insulin on the decidualization process and previous findings are contradictory. We investigated the effect of insulin on the regulation of forkhead box protein O1 (FOXO1), one of the most important transcription factors during decidualization. Endometrial stromal cells were isolated from six healthy, regularly menstruating women and decidualized in vitro. Gene expression levels of six putative FOXO1 target genes (including insulin-like growth factor binding protein-1 (IGFBP1) and prolactin (PRL)) were measured with Real-Time PCR following FOXO1 inhibition or insulin treatment. PI3K inhibition was used to identify the possible mechanism behind regulation. Subcellular localization of FOXO1 was analyzed with immunofluorescence. All the genes (IGFBP1, CTGF, INSR, DCN, LEFTY2), except prolactin, were evaluated as FOXO1 target genes in decidualizing stromal cells. Insulin caused a significant dose-dependent inhibition of the verified FOXO1 target genes. It was also demonstrated that insulin regulated FOXO1 target genes by transcriptional inactivation and nuclear export of FOXO1 via PI3K pathway. However, insulin did not inhibit the morphological transformation of endometrial stromal cells via transcriptional inactivation of FOXO1. This study provides new insights on the action of insulin on the endometrium via regulation of FOXO1. It is suggested that hyperinsulinemia results in dysregulation of a high number of FOXO1 controlled genes that may contribute to endometrial dysfunction and reproductive failure. Our findings may illuminate possible reasons for unexplained infertility.