Estrogen inhibits vaginal tropoelastin and TGF-β1 production

Estrogen and Androgen Receptor Status in Uterosacral Ligaments of Women with Pelvic Organ Prolapse Stratified by the Pelvic Organ Prolapse Histology Quantification System

Menopause is a significant risk factor for pelvic organ prolapse (POP), suggesting that ovarian sex steroids play a major role in the etiology of the condition. POP results from failure of the uterine-cervix-vagina support structures, including the uterosacral ligament (USL). We previously identified consistent degenerative USL phenotypes that occur in POP and used their characteristics to develop a standardized POP Histologic Quantification System (POP-HQ). In this study, POP and matched control USL tissue was first segregated into the unique POP-HQ phenotypes, and specimens were then compared for estrogen receptor (ER) alpha (ERα), ERbeta (ERβ), the G-protein estrogen receptor (GPER), and androgen receptor (AR) content via immunohistochemical staining. ER and AR expression levels in the control USL tissues were indistinguishable from those observed in the POP-A phenotype, and partially overlapped with those of the POP-I phenotype. However, control-USL steroid receptor expression was statistically distinct from the POP-V phenotype. This difference was driven mainly by the increased expression of GPER and AR in smooth muscle, connective tissue, and endothelial cells, and increased expression of ERα in connective tissue. These findings support a multifactorial etiology for POP involving steroid signaling that contributes to altered smooth muscle, vasculature, and connective tissue content in the USL. Furthermore, these data support the concept that there are consistent and distinct degenerative processes that lead to POP and suggest that personalized approaches are needed that target specific cell and tissues in the pelvic floor to treat or prevent this complex condition.

Absorbable Electrospun Poly-4-hydroxybutyrate Scaffolds as a Potential Solution for Pelvic Organ Prolapse Surgery

Women with pelvic organ prolapse (POP) have bothersome complaints that significantly affect their quality of life. While native tissue repair is associated with high recurrence rates, polypropylene knitted implants have caused specific implant-related adverse events that have detrimental, often irreversible, effects. We hypothesize that surgical outcome can be improved with a tissue-engineered solution using an absorbable implant that mimics the natural extracellular matrix (ECM) structure, releases estrogen, and activates collagen metabolism by fibroblasts as the main regulators of wound healing. To this aim, we produced electrospun poly-4-hydroxybutyrate (P4HB) scaffolds and biofunctionalized them with estradiol (E2). The cell-implant interactions relevant for POP repair were assessed by seeding primary POP vaginal fibroblasts isolated from patients on electrospun P4HB scaffolds with 1%, 2%, or 5% E2 and without E2. To test our hypothesis on whether ECM mimicking structures should improve regeneration, electrospun P4HB was compared to knitted P4HB implants. We evaluated vaginal fibroblast proliferation, ECM deposition, and metabolism by quantification of collagen, elastin, and matrix metalloproteinases and by gene expression analysis for 28 days. We established effective E2 drug loading with a steady release over time. Significantly higher cell proliferation, collagen-, and elastin deposition were observed on electrospun P4HB scaffolds as compared to knitted P4HB. For this study, physical properties of the scaffolds were more determinant on the cell response than the release of E2. These results indicate that making these electrospun P4HB scaffolds E2-releasing appears to be technically feasible. In addition, electrospun P4HB scaffolds promote the cellular response of vaginal fibroblasts and further studies are merited to assess if their use results in improved surgical outcomes in case of POP repair.

Role of sex steroid hormones in pelvic organ prolapse

OBJECTIVE

Pelvic organ prolapse (POP) affects a significant percentage of women and contributes to major healthcare costs both in the United States and worldwide. This review examines the current understanding of the role of sex steroid hormones (estrogens, androgens, and progesterone) in POP in premenopausal, perimenopausal, and postmenopausal women.

METHODS

We reviewed the relevant studies on POP related to estrogens, androgens, and progesterone in both animal models and humans.

RESULTS

Estrogen has a profound influence on the synthesis and metabolism of pelvic connective tissues, and may have the ability to both prevent POP and improve prognosis if used therapeutically. There is limited research regarding the role of androgens and progesterone and their receptors in POP and results so far have been contradictory, warranting further study to determine whether changes in androgen and progesterone receptor expression are a cause or effect of POP.

CONCLUSIONS

Because of the role that estrogen plays in maintaining the integrity of pelvic floor connective tissues, we propose that rigorous and well-controlled studies are needed on the role of exogenous estrogen administration as a form of POP prevention. : Video Summary:http://links.lww.com/MENO/A583.

Postmenopausal hormone therapy is accompanied by elevated risk for uterine prolapse

OBJECTIVE

Receptors for estrogen and progesterone are present in the pelvic floor, and therefore, postmenopausal hormone therapy may affect its function. We compared the former use of estradiol-progestogen postmenopausal hormone therapy in nonhysterectomized women with a uterine prolapse surgery (N = 12,072) and control women (N = 33,704).

METHODS

The women with a history of uterine prolapse operation were identified from the Finnish National Hospital Discharge Register, and the control women from the Finnish Central Population Register. The use of hormone therapy was traced from the national drug reimbursement register, and the odd ratios with 95% CIs for prolapse were calculated by using the conditional logistic regression analysis.

RESULTS

The women with uterine prolapse had used hormone therapy more often than control women (N = 4,127; 34.2% vs N = 9,189; 27.3%; P < 0.005). The use of hormone therapy was accompanied by significant (23%-53%) elevations in the risk for prolapse, being higher with longer exposure. The risk elevations (33%-23%) were comparable between sole norethisteroneacetate-estradiol and sole medroxyprogesteroneacetate-estradiol therapy. The use of estradiol in combination with a levonorgestrel releasing intrauterine device was accompanied by a 52% elevation.

CONCLUSIONS

The postmenopausal use of estradiol in combination with various progestogen regimens may weaken the pelvic floor, resulting in uterine prolapse. This data should be incorporated into the information given to the users of estradiol-progestogen hormone therapy.

The role of smooth muscle cells in the pathophysiology of pelvic organ prolapse

Pelvic organ prolapse (POP) is a prevalent and disabling condition. The pathophysiology of prolapse is multifactorial, and no single mechanism adequately explains all aspects of its development. The pathophysiology of POP is complex and incompletely understood. Smooth muscle (SM), an integral part of the vaginal wall and endopelvic structures that support the pelvic viscera, has also been implicated in the pathophysiology of POP. In this article, we review the role of smooth muscle cells (SMC) in the pathophysiology of POP, also addressing the anatomy of SM in pelvic floor, morphometric analysis, biomechanical properties, and potential mechanisms.