Combined estrogen and ghrelin administration restores number of blood vessels and collagen type I/III ratio in the urethral and anal canal submucosa of old ovariectomized rats

Advancing our understanding of genetic risk factors and potential personalized strategies for pelvic organ prolapse

Pelvic organ prolapse is a common gynecological condition with limited understanding of its genetic background. In this work, we perform a genome-wide association meta-analysis comprising 28,086 cases and 546,291 controls from European ancestry. We identify 19 novel genome-wide significant loci, highlighting connective tissue, urogenital and cardiometabolic as likely affected systems. Here, we prioritize many genes of potential interest and assess shared genetic and phenotypic links. Additionally, we present the first polygenic risk score, which shows similar predictive ability (Harrell C-statistic (C-stat) 0.583, standard deviation (sd) = 0.007) as five established clinical risk factors combined (number of children, body mass index, ever smoked, constipation and asthma) (C-stat = 0.588, sd = 0.007) and demonstrates a substantial incremental value in combination with these (C-stat = 0.630, sd = 0.007). These findings improve our understanding of genetic factors underlying pelvic organ prolapse and provide a solid start evaluating polygenic risk scores as a potential tool to enhance individual risk prediction.

Although pelvic organ prolapse is a common gynecological condition, the genetic component of disease risk is not well known. Here the authors find common genetic variants associated with the disease and present a polygenic risk score to enhance individual risk prediction.

Effect of puerarin on collagen metabolism of fibroblasts in pelvic tissue of women with pelvic organ prolapse

The aim of the present study was to investigate the protective effect of puerarin on pelvic organ prolapse (POP) and the underlying mechanisms that regulate the metabolism of human parametrial ligament fibroblasts (HPLFs). HPLFs obtained from the pelvic tissue of patients with (n=10) or without (n=8) POP during hysterectomy were isolated by enzymatic digestion and subsequently identified by immunocytochemistry in a previous study of the authors. Following this, cultured HPLFs were treated with 0.01, 0.10 or 1.00 mmol/l puerarin, followed by detection of proliferation rate by Cell Counting kit‑8 assay. Following incubation with puerarin for 48 h, mRNA and protein expression levels of tissue inhibitor of metalloproteinase‑1 (TIMP‑1), matrix metalloproteinase (MMP)‑2 and ‑9, and collagen (COL)I and III in HPLFs were quantified by reverse transcription‑quantitative polymerase chain reaction, and western blot and gelatin zymography analyses, respectively. MMP‑2 and ‑9 expression levels were increased, whereas expression levels of TIMP‑1, and COL I and III were decreased, in patients with POP compared with healthy controls. Following puerarin treatment, the expression levels of TIMP‑1, and COL I and III were enhanced, whereas MMP‑2 and ‑9 were inhibited. In conclusion, the present study demonstrated evidence increased degradation of the extracellular matrix in pelvic tissues of patients with POP compared with controls, and the protective effect of puerarin against POP via its anti‑degradation effect on collagen. These results provide evidence for puerarin as a novel approach for the treatment of POP.

The effects of conjugated estrogen, raloxifene and soy extract on collagen in rat bones

OBJECTIVE

To evaluate the action of conjugated equine estrogen, raloxifene and isolated or combined genistein-rich soy extracts on collagen fibers in the bones of oophorectomized rats.

MATERIALS AND METHODS

Seventy female rats received testosterone propionate (0.1 µg/g) on the 9th day after birth. At 6 months of age, the rats were administered the vehicle (propylene glycol, 0.5 ml/day), and ten of the rats were randomly chosen to comprise the non-oophorectomized control group (GI). The other 60 rats were ovariectomized and randomized into six groups of ten as follows: GII, vehicle; GIII, conjugated equine estrogen (CEE), 50 µg/kg/day; GIV, raloxifene (RAL), 0.75 mg/kg/day; GV, genistein-rich soy extract (GSE), 300 mg/kg/day; GVI, CEE + GSE, 50 µg/kg/day + 300 mg/kg/day; and GVII, CEE + RAL, 50 µg/kg/day + 0.75 mg/kg/day. Three months after surgery, the drugs were administered for 60 consecutive days. All rats were euthanized, and their left tibiae were removed for histological routine. The histological sections were stained with hematoxylin-eosin, and picrosirius for evaluating bone microarchitecture. Types I and II collagen fibers were analyzed by immunofluorescence. Data analysis was carried out with ANOVA and Tukey's test.

RESULTS

Collagen reduction was significant in the GIII animals when compared to the other groups (p < 0.05). There was no significant difference in the thickness of collagen fibers among the groups. There was a greater quantity of type III collagen in GVI than in the other groups.

CONCLUSION

Our data indicate that conjugated equine estrogen improves bone quality because it increases the quantity of type I collagen while reducing the quantity of thin collagen fibers. In addition, the combination of CEE and raloxifene or genistein-rich soy extract is not as efficient as CEE itself to improve bone quality.

[Effects of delivery and oophorectomy on urethral collagen: an experimental study]

OBJECTIVE

Stereological evaluation of the concentration of type I and III collagen fibers in the urethral tissue of rats subjected to simulated labor and oophorectomy. To compare the concentrations of collagen between oophorectomized and non-oophorectomized rats.

MATERIAL AND METHOD

Sixty adult Wistar rats were divided into six groups. A group made up of virgin rats was used as control group and another group was made up of oophorectomized rats. Two groups underwent vaginal distention for 30 and 120 minutes, respectively. The two other groups were subjected to the same distension periods, followed by oophorectomy. Sixty days later, euthanasia and removal of urethral tissue was carried out for stereological analysis of type I and III collagen after staining with hematoxylin and eosin and picrosirius red.

RESULTS

A decrease in estrogen levels was observed in the oophorectomized rats. There was a reduction of type III collagen in the oophorectomized control group compared to the control group when analyzed independently. No significant differences were observed among the other groups. Type I collagen decreased in all groups compared to the control group. However, in the prolonged vaginal distension and oophorectomy group, these fibers increased.

CONCLUSION

In normal rats, simulation of labor does not alter the collagen III levels. In hypoestrogenic rats, the concentration of collagen type I and III decreased, except in those undergoing prolonged labor simulation in which collagen I increased.

Menopause and obstetric history as risk factors for fecal incontinence in women

BACKGROUND

Fecal incontinence is a highly prevalent condition, especially in women. However, few data on prevalence in women attending primary care are available, particularly regarding the presence of risk factors.

OBJECTIVE

The aim of this study was to determine characteristics of women with fecal incontinence and to analyze obstetric history and menopause as potential risk factors.

DESIGN

Observational study with a cross-sectional design.

SETTINGS

Patients in primary care at 10 health care centers in Barcelona, Spain.

MAIN OUTCOME MEASURES

Fecal incontinence was defined as loss of flatus or liquid/solid stool occurring at least monthly. Data on the following variables were collected by face-to-face interviews and patient questionnaires: demographic and clinical characteristics, obstetric history, menopause data, fecal incontinence, and quality of life. Univariable and multivariable analyses were performed to study the association of potential risk factors with fecal incontinence.

RESULTS

The study included 332 women with a mean age of 60.8 (SD, 17.8) years. The prevalence of fecal incontinence was 12.0% (40/332). Flatus incontinence was reported in 27 patients (67.5%), liquid stool incontinence in 25 (62.5%), and solid stool incontinence in (19) 47.5%. On multivariable analysis, the only independent risk factors for fecal incontinence were an obstetric history of complicated deliveries (instrumentation or podalic presentation; OR, 3.66; 95% CI, 1.54-8.68, P = .003) and menopause (OR, 5.67; 95% CI, 1.35-23.78; P = .018).

LIMITATIONS

The cross-sectional design hampered identification of the time at which the impact of menopausal status occurred, and data obtained from patient interviews was subject to recall bias.

CONCLUSIONS

Complicated deliveries are risk factors for fecal incontinence in women. Fecal incontinence appears to be more prevalent in menopausal women.

Expression of estrogen and progesterone receptors in the anal canal of women according to age and menopause

PURPOSE

Fecal incontinence is highly prevalent, especially in menopausal women. The aim of this study was to analyze the expression of estrogen and progesterone receptors in the anal canal of women in relation to menopausal status and age.

METHODS

Samples of hemorrhoidal tissue were obtained from 34 women undergoing hemorrhoidectomy. The patients were divided into 2 groups: group 1 consisted of women with a menstrual cycle (n = 17) and group 2 consisted of postmenopausal women (n = 17). Immunostaining of hormone receptors was performed using specific antibodies (DAKO, Copenhagen, Denmark) in cells from the internal anal sphincter, the vascular epithelium, and the squamous epithelium. The percentage of positivity of receptors and the association between age and receptor positivity were compared between the 2 groups.

RESULTS

Estrogen receptors were found in the internal anal sphincter in 23.5% in group 1 vs 11.8% in group 2 (P = .656). Progesterone receptors were found in 41.2% in group 1 vs 11.8% of group 2 (P = .118). Squamous epithelium showed estrogen receptors in 52.9% in group 1 vs 64.7% of group 2 (P = .388) and progesterone receptors in 17.6% and 0% in groups 1 and 2, respectively (P = .227). Vascular endothelium showed no receptors. Receptor positivity was not associated with age.

CONCLUSION

No significant differences were found in the detection of estrogen and progesterone receptors in structures of the anal canal in women in relation to menopausal status and age.

Estrogen improves TIMP-MMP balance and collagen distribution in volume-overloaded hearts of ovariectomized females

Our previous studies demonstrate that 17beta-estradiol limits chronic volume overload-induced hypertrophy and improves heart function in ovariectomized rats. One possible cardioprotective mechanism involves the interaction between estrogen, estrogen receptors, and proteins of the extracellular matrix (ECM). The impact of estrogen deficiency and replacement on left ventricular (LV) hypertrophy and ECM protein expression was studied using five female rat groups: intact sham-operated, ovariectomized sham-operated, intact with volume overload, ovariectomized with volume overload, and ovariectomized with volume overload treated with estrogen. After 8 wk, LV protein extracts were evaluated by Western blot analysis for matrix metalloproteinase-2 (MMP-2) and MMP-9, MT1-MMP, tissue inhibitors of MMPs (TIMP)-1, TIMP-2, TIMP-3 and TIMP-4, collagens type I and III, and estrogen receptor alpha and beta expression. MMP proteolytic activity was assessed by zymography. All volume-overloaded groups exhibited LV hypertrophy, which was associated with a loss of interstitial collagen and perivascular fibrosis. After 8 wk of volume overload, 70% of ovariectomized rats developed heart failure, in contrast to only one intact rat. A downregulation of MMP-2, estrogen receptor-alpha (ERalpha), and ERbeta, and upregulation of MMP-9 and MT1-MMP were found in the volume-overloaded hearts of ovariectomized rats. Estrogen treatment improved TIMP-2/MMP-2 and TIMP-1/MMP-9 protein balance, restored ERalpha expression, and prevented MMP-9 activation, perivascular collagen accumulation and development of heart failure. However, estrogen did not fully restore ERbeta expression and did not prevent the increase of MMP-9 expression or loss of interstitial collagen. These results support that estrogen limits undesirable ECM remodeling and LV dilation, in part, through modulation of ECM protein expression in volume-overloaded hearts of ovariectomized rats.

Evaluation of the ratio of collagen type III to collagen type I in periurethral tissues of sexually intact and neutered female dogs

OBJECTIVE

To determine the ratio of collagen type III to collagen type I in the periurethral tissues of sexually intact and neutered female dogs.

ANIMALS

8 neutered and 34 sexually intact female dogs.

PROCEDURES

Tissues were obtained from female dogs euthanized for non-urinary tract-related reasons. Indirect immunofluorescent antibody detection of type I and collagen type III was performed by use of confocal microscopy on 2 periurethral samples from each dog, and the ratios of collagen type III to type I area fraction and total area were determined.

RESULTS

No significant differences were detected in the collagen ratios of periurethral tissues between sexually intact and neutered female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

In contrast to differences in periurethral collagen content found between pre- and postmenopausal women, such differences may not occur in dogs. This implies that changes in pelvic organ support structures may not play an important role in urinary incontinence in neutered female dogs. Further evaluation is needed to determine the role of age on collagen and pelvic organ support structures in the pathogenesis of canine urinary incontinence.

Diminished vaginal HOXA13 expression in women with pelvic organ prolapse

OBJECTIVE

Homeobox genes are transcriptional regulators that orchestrate embryonic development. The HOXA13 gene is responsible for the development of the vagina and regulates extracellular matrix constituents. We hypothesized that vaginal expression of HOXA13 may be decreased in women with pelvic organ prolapse (POP) and sought to determine if hypoestrogenism affects its expression.

METHODS

Biopsy specimens were obtained from the anterior apex of the vagina from women with and without POP. Immunohistochemistry and real-time polymerase chain reaction were used to determine HOXA13 expression in premenopausal controls, in premenopausal women receiving leuprolide acetate, and in premenopausal and postmenopausal women with POP.

RESULTS

HOXA13 was expressed in all specimens. HOXA13 expression was 14-fold lower in premenopausal women with prolapse than in premenopausal controls (P < 0.001). In both POP groups, HOXA13 expression was lower than in the leuprolide group (P <or= 0.001). There were no differences in HOXA13 expression between premenopausal controls and women treated with leuprolide acetate (P = 1.0) or between the premenopausal and postmenopausal POP group (P = 1.0).

CONCLUSIONS

Vaginal HOXA13 expression is diminished in women with POP compared with women with normal support. In women with POP, expression of HOXA13 was not affected by menopause. Expression of HOXA13 was also not affected by exposure to leuprolide acetate, suggesting that estrogen and HOXA13 work through separate pathways in the extracellular matrix metabolism of the vagina. Understanding genetic predispositions to developing POP may identify younger patients at risk who may benefit from preventive strategies such as weight loss or smoking cessation and not necessarily from estrogen therapy.

Combined estrogen and ghrelin administration decreases expression of p27(kip1) and proportion of isomyosin type I in the striated urethral and anal sphincters and levator ani of old ovariectomized rats

We compared estrogen and/or ghrelin effects on pelvic floor muscles in old versus young adult ovariectomized rats. Ovariectomized Fisher 344 rats (18 and 3 months old, n = 24 x 2) received 42 daily intraperitoneal 17-beta estradiol (10 microg kg(-1)), ghrelin (2 microg kg(-1)), both, or vehicle (n = 6 x 4/group). Cytoplasmic p27(kip1) expression and isomyosin I proportion in striated urethral and anal sphincters and levator ani were measured, respectively, by Western blot analysis and gel electrophoresis with immunohistochemistry of muscle ghrelin receptors and radioimmunoassay of circulating growth hormone. In young adult rats, estrogen significantly decreased cytoplasmic p27(kip1) and isomyosin I signal intensities. In old rats, ghrelin and estrogen/ghrelin significantly decreased both intensities with greater estrogen/ghrelin effect. Ghrelin receptors were not immunostained in any muscle. Estrogen and/or ghrelin significantly increased or decreased, respectively, circulating growth hormone in old and young adult rats. Estrogen/ghrelin administration reversed pelvic floor muscle ageing changes in old ovariectomized rats through growth hormone production.