Elastin metabolism in pelvic tissues: is it modulated by reproductive hormones?

Functional outcome of the anterior vaginal wall in a pelvic surgery injury rat model after treatment with stem cell-derived progenitors of smooth muscle cells

BACKGROUND

Stem-cell-derived therapy is a promising option for tissue regeneration. Human iPSC-derived progenitors of smooth muscle cells (pSMCs) exhibit limited proliferation and differentiation, which minimizes the risk of tumor formation while restoring smooth muscle cells (SMCs). Up to 29% of women suffer from recurrence of vaginal prolapse after prolapse surgery. Therefore, there is a need for therapies that can restore vaginal function. SMCs contribute to vaginal tone and contractility. We sought to examine whether human pSMCs can restore vaginal function in a rat model.

METHODS

Female immunocompromised RNU rats were divided into 5 groups: intact controls (n = 12), VSHAM (surgery + saline injection, n = 35), and three cell-injection groups (surgery + cell injection using pSMCs from three patients, n = 14/cell line). The surgery to induce vaginal injury was analogous to prolapse surgery. Menopause was induced by surgical ovariectomy. The vagina, urethra, bladder were harvested 10 weeks after surgery (5 weeks after cell injection). Organ bath myography was performed to evaluate the contractile function of the vagina, and smooth muscle thickness was examined by tissue immunohistochemistry. Collagen I, collagen III, and elastin mRNA and protein expressions in tissues were assessed.

RESULTS

Vaginal smooth muscle contractions induced by carbachol and KCl in the cell-injection groups were significantly greater than those in the VSHAM group. Collagen I protein expression in the vagina of the cell-injections groups was significantly higher than in the VSHAM group. Vaginal elastin protein expression was similar between the cell-injection and VSHAM groups. In the urethra, gene expression levels of collagen I, III, and elastin were all significantly greater in the cell-injection groups than in the VSHAM group. Collagen I, III, and elastin protein expression of the urethra did not show a consistent trend between cell-injection groups and the VSHAM group.

CONCLUSIONS

Human iPSC-derived pSMCs transplantation appears to be associated with improved contractile function of the surgically injured vagina in a rat model. This is accompanied by changes in extracellular protein expression the vagina and urethra. These observations support further efforts in the translation of pSMCs into a treatment for regenerating the surgically injured vagina in women who suffer recurrent prolapse after surgery.

Early growth response 2, a novel target of pelvic organ prolapse, is highly expressed in anterior vaginal wall tissues with pelvic organ prolapse

Pelvic organ prolapse (POP) is a common disorder among women that negatively affects women's quality of life. Early growth response 2 (EGR2) is a transcription factor that regulates cell growth. The present study aimed to explore the role of EGR2 in POP progression and provided a new target for the treatment and prevention of POP. Firstly, we extracted primary vaginal anterior wall fibroblasts from POP tissues and non-POP tissues and then constructed an EGR2-silencing lentivirus for further study. Immunoblotting, qPCR, TUNEL assay, CCK-8 assay, dual luciferase assay, and ELISA assay were carried out. EGR2 expression was much higher in POP tissues than in control tissues, and EGR2 expression positively correlated with cytokine signaling 3 (SOCS3) expression. Knockdown of EGR2 increased cell proliferation, upregulated PCNA expression, and reduced apoptosis in POP fibroblasts. Moreover, we found that the knockdown of EGR2 increased COL1A1, COL3A1, and Elastin expression and decreased MMP2 and MMP9 activities, and knockdown of EGR2 increased TGF-β/Smad pathway activity in POP fibroblasts. Interestingly, the results of dual luciferase assay demonstrated that EGR2 was able to increase SOCS3 transcriptional activity. EGR2 knockdown alleviated the apoptosis of POP fibroblasts by reducing SOCS3 expression and improving the proliferation and collagen synthesis of POP fibroblasts. Overall, our study illustrated that EGR2 was highly expressed in POP tissues, and knockdown of EGR2 alleviated apoptosis and reduced matrix degradation in POP fibroblasts. This study might provide a new insight into the pathogenesis of POP.

Advances in the molecular pathogenesis and cell therapy of stress urinary incontinence

Stress urinary incontinence (SUI) is very common in women. It affects patients' mental and physical health, and imposed huge socioeconomic pressure. The therapeutic effect of conservative treatment is limited, and depends heavily on patient persistence and compliance. Surgical treatment often brings procedure-related adverse complications and higher costs for patients. Therefore, it is necessary to better understand the potential molecular mechanisms underlying stress urinary incontinence and develop new treatment methods. Although some progress has been made in the basic research in recent years, the specific molecular pathogenic mechanisms of SUI are still unclear. Here, we reviewed the published studies on the molecular mechanisms associated with nerves, urethral muscles, periurethral connective tissue and hormones in the pathogenesis of SUI. In addition, we provide an update on the recent progresses in research on the use of cell therapy for treating SUI, including research on stem cells therapy, exosome differentiation and gene regulation.

The Most Common Functional Disorders and Factors Affecting Female Pelvic Floor

The pelvic floor (PF) is made of muscles, ligaments, and fascia, which ensure organ statics, maintain muscle tone, and are involved in contractions. This review describes the myofascial relationships of PF with other parts of the body that determine the proper functions of PF, and also provides insight into PF disorders and the factors contributing to them. PF plays an important role in continence, pelvic support, micturition, defecation, sexual function, childbirth, and locomotion, as well as in stabilizing body posture and breathing, and cooperates with the diaphragm and postural muscles. In addition, PF associates with distant parts of the body, such as the feet and neck, through myofascial connections. Due to tissue continuity, functional disorders of muscles, ligaments, and fascia, even in the areas that are distant from PF, will lead to PF disorders, including urinary incontinence, fecal incontinence, prolapse, sexual dysfunction, and pain. Dysfunctions of PF will also affect the rest of the body.

Animal Models and Alternatives in Vaginal Research: a Comparative Review

While developments in gynecologic health research continue advancing, relatively few groups specifically focus on vaginal tissue research for areas like wound healing, device development, and/or drug toxicity. Currently, there is no standardized animal or tissue model that mimics the full complexity of the human vagina. Certain practical factors such as appropriate size and anatomy, costs, and tissue environment vary across species and moreover fail to emulate all aspects of the human vagina. Thus, investigators are tasked with compromising specific properties of the vaginal environment as it relates to human physiology to suit their particular scientific question. Our review aims to facilitate the appropriate selection of a model aptly addressing a particular study by discussing pertinent vaginal characteristics of conventional animal and tissue models. In this review, we first cover common laboratory animals studied in vaginal research-mouse, rat, rabbit, minipig, and sheep-as well as human, with respect to the estrus cycle and related hormones, basic reproductive anatomy, the composition of vaginal layers, developmental epithelial origin, and microflora. In light of these relevant comparative metrics, we discuss potential selection criteria for choosing an appropriate animal vaginal model. Finally, we allude to the exciting prospects of increasing biomimicry for in vitro applications to provide a framework for investigators to model, interpret, and predict human vaginal health.

Secretomes of human pluripotent stem cell-derived smooth muscle cell progenitors upregulate extracellular matrix metabolism in the lower urinary tract and vagina

BACKGROUND

Adult mesenchymal stem cells (MSCs) have been studied extensively for regenerative medicine; however, they have limited proliferation in vitro, and the long culture time induces cell senescence. MSCs also contribute to tissue repair through their paracrine function. In this study, we sought to examine the paracrine effects of human smooth muscle cell progenitors (pSMC) on the urethra and adjacent vagina of stress urinary incontinence rodents. We use human pluripotent stem cell (PSC) lines to derive pSMCs to overcome the issue of decreased proliferation in tissue culture and to obtain a homogenous cell population.

METHOD

Three human PSC lines were differentiated into pSMCs. The conditioned medium (CM) from pSMC culture, which contain pSMC secretomes, was harvested. To examine the effect of the CM on the extracellular matrix of the lower urinary tract, human bladder smooth muscle cells (bSMCs) and vaginal fibroblasts were treated with pSMC-CM in vitro. Stress urinary incontinence (SUI) was induced in rats by surgical injury of the urethra and adjacent vagina. SUI rats were treated with pSMC-CM and monitored for 5 weeks. Urethral pressure testing was performed prior to euthanasia, and tissues were harvested for PCR, Western blot, and histological staining. Kruskal-Wallis one-way ANOVA test and Student t test were used for statistical comparisons.

RESULTS

pSMC-CM upregulated MMP-2, TIMP-2, collagen, and elastin gene expression, and MMP-9 activity in the human bladder and vaginal cells consistent with elastin metabolism modulation. pSMC-CM treatment in the SUI rat improved urethral pressure (increase in leak point pressure compared to intact controls, p < 0.05) and increased collagen and elastin expression in the urethra and the adjacent vagina.

CONCLUSION

Conditioned media from smooth muscle cell progenitors derived from human pluripotent stem cells improved urethral leak point pressure and collagen and elastin content in the SUI rat. These findings suggest a novel therapeutic potential for PSC-based treatments for SUI and pelvic floor disorders where tissues are affected by collagen, elastin, and smooth muscle loss.

An Avant-Garde Model of Injury-Induced Regenerative Vaginal Wound Healing

Objective: To design and validate a novel murine model of full-thickness (FT) vaginal wound healing that mirrors postinjury tissue repair and underscores the impact of estrogen signaling-driven healing kinetics, inflammation, and neovascularization. Approach: Five-week-old female CD1 mice were subjected to two 1-mm FT wounds. To assess wound healing kinetics, vaginas were harvested at 6, 12, 18, 24, 48, and 72 h and 7 days postinjury. Wounds from all time points were analyzed by hematoxylin and eosin and trichrome to, respectively, assess the rate of wound closure and tissue deposition. Inflammatory leukocyte (CD45), neutrophil (Ly6G), and macrophage (F480 and CD206) infiltration was examined by immunohistochemistry (IHC) and the resulting anti-inflammatory M2 (CD206)/total (F480) macrophage ratio quantified. Neovascularization (CD31) and estrogen receptor-α (ERα) expression levels were similarly determined by IHC. Results: We observed rapid healing with resolution of mucosal integrity by 48 h (p < 0.05), and overall neutrophils and polarized type 2 macrophages (M2) apexed at 12 h and reduced to near control levels by day 7 postinjury. Tissue repair was virtually indistinguishable from the surrounding vagina. CD31+ vessels increased between 12 h and day 7 and ERα trended to decrease at 12 h postinjury and rebound at day 7 to uninjured levels. Innovation: A proof-of-concept murine model to study vaginal wound healing kinetics and postinjury regenerative repair in the vagina was developed and verified. Conclusion: We surmise that murine vaginal mucosal repair is accelerated and potentially regulated by estrogen signaling through the ERα, thus providing a cellular and molecular foundation to understand vaginal healing responses to injury.

Effect of integrin β1 in the treatment of stress urinary incontinence by electrical stimulation

The aim of the present study was to investigate the protective effect of integrin β1 in the treatment of stress urinary incontinence (SUI) by electrical stimulation, and the underlying mechanisms by which electrical stimulation regulates the collagen metabolism of female vaginal wall fibroblasts (FVWFs). FVWFs obtained from the vaginal wall tissue of patients with (Ingelman-Sundberg scale; grade II, n=8; grade III, n=10) or without (n=8) SUI during gynecological operations were isolated by enzymatic digestion and subsequently identified by immunocytochemistry. Following this, cultured FVWFs were treated with an inhibitor of integrin β1, recombinant human integrin β1 and electrical stimulation (100 mv/mm, 2 h, 20 Hz), followed by total mRNA and protein extraction. mRNA and protein expression levels of integrin β1, transforming growth factor (TGF)-β1 and collagen (COL) I and III in FVWFs were quantified by reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis respectively. Integrin β1, TGF-β1 and COL I and III expression levels were decreased in patients with SUI compared with healthy controls, and the grade III group had lower levels than the grade II group. Following electrical stimulation treatment, the expression levels of TGF-β1, COL I and III were enhanced in the grade II group, but not in the grade III group. Nevertheless, the inhibitor of integrin β1 reduced the protective effect of electrical stimulation in the grade II group. In addition, electrical stimulation combined with recombinant human integrin β1 could also protect cells from SUI in the grade III group. The present study provides evidence for the increased degradation of the extracellular matrix and integrin β1 in the vaginal wall tissues of patients with SUI, and the protective effect of electrical stimulation against SUI via integrin β1. These results provide a novel mechanism for the treatment of SUI using electrical stimulation.

Electrical stimulation activates calpain 2 and subsequently upregulates collagens via the integrin β1/TGF-β1 signaling pathway

Stress urinary incontinence (SUI) is a public health issue attributed to weakened pelvic supporting tissues. Electrical stimulation (ES) is one of the first-line conservative treatments for SUI. However, the underlying mechanism of ES in the treatment of SUI is not clear. Here, we show that ES suppresses cell apoptosis and upregulates collagen expression by functioning as a cell growth inducer to activate the calpain 2/talin 1/integrin β1/transforming growth factor (TGF)-β1 axis. Specifically, ES promoted Ca²⁺ to flow into the cytoplasm through the calcium channel, Cav 3.2, thereby activating calpain 2. Then, the activated calpain 2 cleaved talin 1, which induced the activation of integrin β1 and upregulated the TGF-β1-mediated transcription of collagen I and III. Notably, blocking Cav 3.2 suppressed calcium influx and inhibited the activation of downstream proteins. Furthermore, the knockdown of calpain 2 resulted in the reduction of cleaved talin 1, and the shRNA-integrin β1 treatment downregulated the level of activated integrin β1 and the expression of TGF-β1-induced collagen I and III. An association of the ES-modulated collagen I and III upregulation with the therapeutic effect of the ES-Ca²⁺/calpain 2/talin 1/integrin β1/TGF-β1 axis was demonstrated in mouse fibroblast and mouse SUI models established through vaginal distension (VD). This outcome provides insight into clinical diagnosis and treatment.

Relaxin receptor deficiency promotes vascular inflammation and impairs outward remodeling in arteriovenous fistulas

The pathophysiology of arteriovenous fistula (AVF) maturation failure is not completely understood but impaired outward remodeling (OR) and intimal hyperplasia are thought to be contributors. This adverse vascular response after AVF surgery results from interplay between vascular smooth muscle cells (VSMCs), the extracellular matrix (ECM), and inflammatory cells. Relaxin (RLN) is a hormone that acts on the vasculature via interaction with RLN/insulin-like peptide family receptor 1 (RXFP1), resulting in vasodilatation, ECM remodeling, and decreased inflammation. In the present study, we evaluated the consequences of RXFP1 knockout ( Rxfp1-/-) on AVF maturation in a murine model of AVF failure. Rxfp1-/- mice showed a 22% decrease in vessel size at the venous outflow tract 14 d after AVF surgery. Furthermore, a 43% increase in elastin content was observed in the lesions of Rxfp1-/- mice and coincided with a 41% reduction in elastase activity. In addition, Rxfp1-/- mice displayed a 6-fold increase in CD45+ leukocytes, along with a 2-fold increase in monocyte chemoattractant protein 1 (MCP1) levels, when compared with wild-type mice. In vitro, VSMCs from Rxfp1-/- mice exhibited a synthetic phenotype, as illustrated by augmentation of collagen, fibronectin, TGF-β, and platelet-derived growth factor mRNA. In addition, VSMCs derived from Rxfp1-/- mice showed a 5-fold increase in cell migration. Finally, RXFP1 and RLN expression levels were increased in human AVFs when compared with unoperated cephalic veins. In conclusion, RXFP1 deficiency hampers elastin degradation and results in induced vascular inflammation after AVF surgery. These processes impair OR in murine AVF, suggesting that the RLN axis could be a potential therapeutic target for promoting AVF maturation.-Bezhaeva, T., de Vries, M. R., Geelhoed, W. J., van der Veer, E. P., Versteeg, S., van Alem, C. M. A., Voorzaat, B. M., Eijkelkamp, N., van der Bogt, K. E., Agoulnik, A. I., van Zonneveld, A.-J., Quax, P. H. A., Rotmans, J. I. Relaxin receptor deficiency promotes vascular inflammation and impairs outward remodeling in arteriovenous fistulas.

Impact of subsequent pregnancies on pelvic floor functional anatomy

INTRODUCTION AND HYPOTHESIS

Vaginal childbirth clearly has an effect on pelvic floor anatomy, and pregnancy itself also likely plays a role. This study investigated the effects of consecutive pregnancies by comparing pelvic organ support and function in urogynecological patients delivered by cesarean section (CS) only.

METHODS

This was a retrospective study using 161 archived data sets of urogynecological patients delivered exclusively by CS presenting with symptoms of pelvic floor dysfunction between 2007 and 2015. Patients had undergone an interview, clinical examination using the Pelvic Organ Prolapse Quantification (POP-Q) system, and 3D/4D translabial ultrasound (TLUS) using Voluson systems. Measures of functional pelvic floor anatomy were obtained from stored ultrasound (US) volumes at a later date, using proprietary software, and blinded against all other data.

RESULTS

One hundred and sixty-one women delivered exclusively by CS were seen in a urogynecological clinic. Volume data analysis was possible in 151 patients. Mean age was 52 (26-82) years, with a mean body mass index (BMI) of 29.5 (18.4-48.7) kg/m². Forty-three (28.5%) women had one CS, 67 (44.4%) had two, and 41 (27.1%) had three or more. On multivariate analysis, adjusting for age, BMI, history of hysterectomy, and incontinence or prolapse surgery, there were no significant differences between groups.

CONCLUSIONS

On comparing women with one, two, or three or more CS, we found no significant differences in any measured sonographic parameters of pelvic organ descent and pelvic floor muscle function. This implies that subsequent pregnancies after the first are unlikely to exert significant additional effects on pelvic floor functional anatomy.

Differences in urinary incontinence symptoms and pelvic floor structure changes during pregnancy between nulliparous and multiparous women

Background

This study was performed to compare changes in urinary incontinence (UI) symptoms and pelvic floor structure during pregnancy between nulliparous and multiparous women.

Methods

A cross-sectional survey was performed among pregnant women from July 2016 to January 2017. In total, 358 pregnant women from two hospitals underwent an interview and pelvic floor transperineal ultrasound assessment. A questionnaire regarding sociodemographic, gynecological, obstetric features and the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) were used for the interview. Imaging data sets were analyzed offline to assess the bladder neck vertical position (BNVP), urethral angles (α, β, and γ angles), and hiatal area (HA) at rest and at maximal Valsalva maneuver (VM).

Results

After excluding 16 women with invalid data, 342 women were included. The prevalence (χ² = 9.15, P = 0.002), frequency (t = 2.52, P = 0.014), usual amount of UI (t = 2.23, P = 0.029) and scores of interference with daily life (t = 2.03, P = 0.045) during pregnancy were higher in multiparous than nulliparous women. A larger bladder neck descent (BND) (F = 4.398, P < 0.001), HA (F = 6.977, P < 0.001), α angle (F = 2.178, P = 0.030), β angle (F = 4.404, P < 0.001), and γ angle (F = 2.54, P = 0.011) at VM were discovered in pregnant women with UI than without UI. Multiparous women had a significantly higher BND (t = 2.269, P = 0.024) and a larger α angle (F = 2.894, P = 0.004), β angle (F = 2.473, P = 0.014), and γ angle (F = 3.255, P = 0.001) at VM than did nulliparous women.

Conclusion

Multiparous women experienced more obvious UI symptoms and pelvic floor structure changes during pregnancy than did nulliparous women.

Effect of Spinal Manipulation on Pelvic Floor Functional Changes in Pregnant and Nonpregnant Women: A Preliminary Study

OBJECTIVE

The aim of this study was to investigate whether a single session of spinal manipulation of pregnant women can alter pelvic floor muscle function as measured using ultrasonographic imaging.

METHODS

In this preliminary, prospective, comparative study, transperineal ultrasonographic imaging was used to assess pelvic floor anatomy and function in 11 primigravid women in their second trimester recruited via notice boards at obstetric caregivers, pregnancy keep-fit classes, and word of mouth and 15 nulliparous women recruited from a convenience sample of female students at the New Zealand College of Chiropractic. Following bladder voiding, 3-/4-dimensional transperineal ultrasonography was performed on all participants in the supine position. Levator hiatal area measurements at rest, on maximal pelvic floor contraction, and during maximum Valsalva maneuver were collected before and after either spinal manipulation or a control intervention.

RESULTS

Levator hiatal area at rest increased significantly (P < .05) after spinal manipulation in the pregnant women, with no change postmanipulation in the nonpregnant women at rest or in any of the other measured parameters.

CONCLUSION

Spinal manipulation of pregnant women in their second trimester increased the levator hiatal area at rest and thus appears to relax the pelvic floor muscles. This did not occur in the nonpregnant control participants, suggesting that it may be pregnancy related.

Quantitative Sonographic Differences in Mid-Urethra between Postmenopausal Women with and without Stress Urinary Incontinence

AIM

The aim of this study was to evaluate midurethral tissue characteristics in continent and stress urinary incontinent postmenopausal women by using transvaginal ultrasound gray-level histogram.

METHODS

Thirty-seven patients with stress urinary incontinence (SUI) and 77 patients without SUI were evaluated. Vaginal ultrasound gray-level histograms were performed by 2 gynecologists blinded to patients' SUI statuses. The mean gray-level (MGL) of ultrasound gray-level histogram, representing the echogenicity of a region of interest, was measured in the anterior and posterior midurethral wall along a vertical ultrasound beam. The difference in MGL between anterior and posterior (AP difference) midurethra was calculated.

RESULTS

The MGL value of SUI patients was found to be lower in posterior (p = 0.008) and higher in anterior midurethral region (p = 0.001) when compared with control group. In addition, the difference in MGL between anterior and posterior midurethra (AP difference) was found to be higher in SUI group (p < 0.001). Multivariate analysis by logistic regression including confounding factors revealed that AP difference was independently associated with presence of SUI (adjusted OR 1.14, 95% CI 1.08-1.20, p < 0.001). Intra- and inter-observer reproducibility was found to be high with intraclass correlation coefficient of 0.83 and 0.78, respectively.

CONCLUSION

Postmenopausal SUI patients might have a distinct midurethral echogenicity pattern with the quantitative ultrasonography.

iTRAQ-based proteomic profiling of the marine medaka (Oryzias melastigma) gonad exposed to BDE-47

A recent study demonstrated that 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) may have an adverse effect on the reproduction in marine medaka (Oryzias melastigma), but the molecular mechanisms remain largely unknown. In this study, we investigated the protein expression profiles of male and female gonads of O. melastigma exposed to dietary BDE-47 at two dosages (0.65 and 1.30 μg/g/day, respectively) for 21 days. Extracted proteins were labeled with iTRAQ and analyzed on a MALDI TOF/TOF analyzer, as results, 133 and 144 unique proteins were identified in testis and ovary, respective, and they exerted dose- and sex-dependent expression patterns. In testis, among the 42 differentially expressed proteins; down-regulation of histone variants and parvalbumins implicated BDE-47 may disrupt the spermatogenesis and induce sterility in fishes. In ovary, 38 proteins were differentially expressed; the elevation of vitellogenins and apolipoprotein A-I expression indicated BDE-47 acts as an estrogen-mimicking compound and led to reproductive impairment in O. melastigma.

Assessing the impact of twin pregnancies on the pelvic floor using 3-dimensional sonography: a pilot study

OBJECTIVES

The purpose of this study was to compare the morphologic characteristics of the pelvic floor musculature between women with twin and singleton pregnancies.

METHODS

We conducted a cross-sectional case-control study of 40 nulliparous women aged 20 to 38 years to compare women with singleton pregnancies (n = 23) to women with twin pregnancies (n = 17). Biometric measurements of the levator hiatus and the sagittal and coronal diameters were made by transperineal 3-dimensional sonography between the 28th and 38th gestational weeks. Comparisons were statistically assessed by the unpaired Student t test and Mann-Whitney U test.

RESULTS

For the women with singleton pregnancies, the mean sagittal diameters at rest, during the Valsalva maneuver, and during pelvic floor contraction were 5.3, 5.7, and 4.5 cm, respectively, and the mean coronal diameters under these conditions were 3.8, 4.1, and 3.6 cm. For the women with twin pregnancies, the corresponding values were as follows: mean sagittal diameters, 5.3, 5.8, and 4.6 cm; and mean coronal diameters, 4.3, 4.3, and 3.8 cm. The differences in coronal diameters were statistically significant at rest (P < .01) and during contraction (P = .04). The mean levator hiatal areas for the women with singleton pregnancies were 14.6, 16.9, and 11.7 cm(2) at rest, during Valsalva, and during contraction, respectively; for the women with twin pregnancies, these values were 16.0, 18.6, and 12.6 cm(2).

CONCLUSIONS

Hiatal measurements were higher in twin than in singleton pregnancies, with coronal diameters reaching significance at rest and during contraction, suggesting that pelvic support undergoes greater changes during twin pregnancy.

Animal models of female pelvic organ prolapse: lessons learned

Pelvic organ prolapse is a vaginal protrusion of female pelvic organs. It has high prevalence worldwide and represents a great burden to the economy. The pathophysiology of pelvic organ prolapse is multifactorial and includes genetic predisposition, aberrant connective tissue, obesity, advancing age, vaginal delivery and other risk factors. Owing to the long course prior to patients becoming symptomatic and ethical questions surrounding human studies, animal models are necessary and useful. These models can mimic different human characteristics - histological, anatomical or hormonal, but none present all of the characteristics at the same time. Major animal models include knockout mice, rats, sheep, rabbits and nonhuman primates. In this article we discuss different animal models and their utility for investigating the natural progression of pelvic organ prolapse pathophysiology and novel treatment approaches.

Estrogen-related genome-based expression profiling study of uterosacral ligaments in women with pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

The aim of the study was to identify the differential expression of estrogen-related genes that may be involved in the menopause and pelvic organ prolapse (POP) using microarray analysis.

METHODS

An age, parity, and menopausal status-matched case-control study with 12 POP patients and 5 non-POP patients was carried out. The study was conducted from January to December 2010 at Yonsei University, Severance Hospital. We examined microarray gene expression profiles in uterosacral ligaments (USLs) from POP and non-POP patients. Total RNA was extracted from USL samples to generate labeled cDNA, which was hybridized to microarrays and analyzed for the expression of 44,049 genes. We identified differentially expressed genes and performed functional clustering. After clustering, we focused on transcriptional response and signal transduction gene clusters, which are associated with estrogen, and then validated the changes of gene expression levels observed with the microarray analysis using quantitative polymerase chain reaction (qPCR).

RESULTS

The data from the microarray analysis using more than a 1.5-fold change with p value <0.05 resulted in 143 upregulated genes and 87 downregulated genes. Of 59 genes identified to be associated with signal transduction and transcription, 4 genes were chosen for qPCR that have been classified to be associated with estrogen. We found that estrogen receptor-related receptor-α (ERRα) was downregulated and that the expression of death-associated protein kinase 2 (DAPK 2), signal-transducing adaptor protein-2 (STAP-2), and interleukin (IL)-15 were upregulated.

CONCLUSIONS

We found four differentially expressed genes by microarray analysis that may account for the way in which changes in estrogen level affect POP pathophysiology.

The role of the ERK1/2 signalling pathway in the pathogenesis of female stress urinary incontinence

Objective:

To investigate the role of extracellular-regulated protein kinase (ERK)1/2 and phosphorylated (p)-ERK1/2 in the pathogenesis of female stress urinary incontinence (SUI).

Methods:

Anterior vaginal wall tissue was collected from women with SUI and control subjects. Immunohistochemistry and Western blotting were performed for p-ERK1/2. Primary vaginal fibroblast cultures were incubated in the presence or absence of PD98059 (an inhibitor of ERK kinase) and levels of collagen I and III mRNA and protein were examined by quantitative reverse transcription–polymerase chain reaction and Western blot, respectively.

Results:

Levels of p-ERK1/2 were significantly lower in vaginal wall tissue from patients with SUI ( n = 10) compared with controls ( n = 10). PD98059 treatment significantly reduced levels of collagen I and III mRNA and protein.

Conclusions:

Female SUI is associated with reduced levels of p-ERK1/2 compared with controls, and inhibition of the ERK1/2 signalling pathway inhibits collagen type I and III synthesis in vaginal wall fibroblasts.

Reprogramming of fibroblasts from older women with pelvic floor disorders alters cellular behavior associated with donor age

We aimed to derive induced pluripotent stem cell (iPSC) lines from vaginal fibroblasts from older women with pelvic organ prolapse. We examined the effect of donor age on iPSCs and on the cells redifferentiated from these iPSCs. Vaginal fibroblasts were isolated from younger and older subjects for reprogramming. iPSCs were generated simultaneously using an excisable polycistronic lentiviral vector expressing Oct4, Klf4, Sox2, and cMyc. The pluripotent markers of iPSCs were confirmed by immunocytochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Spectral karyotyping was performed. The ability of the iPSCs to differentiate into three germ layers was confirmed by embryoid body and teratoma formation. Senescence marker (p21, p53, and Bax) expressions were determined by qRT-PCR and Western blot. The iPSCs were redifferentiated to fibroblasts and were evaluated with senescence-associated β-galactosidase (SA) activity and mitotic index using time-lapse dark-field microscopy. iPSCs derived from both the younger and older subjects expressed pluripotency markers and showed normal karyotype and positive teratoma assays. There was no significant difference in expression of senescence and apoptosis markers (p21, p53, and Bax) in iPSCs derived from the younger subject compared with the older subject. Furthermore, fibroblasts redifferentiated from these iPSCs did not differ in SA activity or mitotic index. We report successful derivation of iPSCs from women with pelvic organ prolapse. Older age did not interfere with successful reprogramming. Donor age differences were not observed in these iPSCs using standard senescence markers, and donor age did not appear to affect cell mitotic activity in fibroblasts redifferentiated from iPSCs.

The impact of cesarean delivery on pelvic floor dysfunction in lysyl oxidase like-1 knockout mice

OBJECTIVE

: Lysyl oxidase like-1 (LOXL1) knockout mice have abnormal elastic fiber homeostasis and frequently develop pelvic floor dysfunction after pregnancy and delivery. The objective of this study was to test the hypothesis that tissue changes associated with vaginal delivery lead to pelvic floor dysfunction as a result of abnormal elastic fiber homeostasis.

METHODS

: Female LOXL1 knockout mice delivered either spontaneously or by cesarean delivery. Mice were assessed weekly for pelvic organ prolapse (POP). At 12 weeks postpartum, lower urinary tract function was assessed by cystometry and leak-point pressure testing. Urethrovaginal cross-sections were analyzed using a histologic grading scale to assess elastin fiber disorganization.

RESULTS

: A total of 39 mice delivered by spontaneous vaginal delivery and 36 by cesarean delivery. Twelve weeks after spontaneous vaginal delivery or cesarean delivery, 23 (59%) and 11 (31%) mice had developed POP, respectively. The mean time to develop POP was 7.2 weeks after spontaneous vaginal delivery and 10.5 weeks after cesarean delivery (log rank, P = 0.0008). The Cox proportional hazard ratio was 0.55 (95% confidence interval, 0.38-0.79). Mice with POP had increased frequency of bladder contractions not associated with voiding during cystometry (P = 0.02). POP, but not mode of delivery, was associated with increased elastic fiber disorganization.

CONCLUSIONS

: Cesarean delivery delays the development of POP in LOXL1 knockout mice. POP is associated with increased bladder contraction frequency and increased elastic fiber disorganization in the urethra and vagina. The mechanisms underlying these findings warrant further investigation.

Identification of protein marker in vaginal wall tissues of women with stress urinary incontinence by protein chip array

AIM

We sought to investigate protein biomarkers for stress urinary incontinence (SUI) in vaginal tissues using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) and examine if this is a reliable methodology to examine proteins in small tissue specimens.

MATERIAL AND METHODS

  We compared protein expression profile of vaginal tissue from women with SUI and continent controls. A 22.6kDa peak was identified by subsequent weak cation-exchange, reverse-phase fractionation, gel electrophoresis, and trypsin digestion, then analyzed by matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) and MALDI MS-MS. Biomarker identity and expression level were confirmed by Western-blotting and immunohistochemistry.

RESULTS

Expression of the 22.6kDa protein, identified as SM-22α, was significantly higher in women with SUI versus controls. A 3×3-mm tissue sample was sufficient for identification. Western-blot/immunohistochemistry confirmed the SELDI-TOS MS findings.

CONCLUSION

SM-22α, a marker for myofibroblasts, was identified as a biomarker of SUI. Differential protein profiling by SELDI-TOF MS is a powerful and reliable tool for urogynecological research as it allows us to study an array of proteins simultaneously using small tissue samples.

Expression of apoptotic factors in vaginal tissues from women with urogenital prolapse

AIMS

Increased apoptotic activity in pelvic tissues may contribute to development of pelvic floor disorders. We evaluated expression of apoptotic factors (Bcl-2 family) in vaginal tissues from women with pelvic organ prolapse (POP) and how these factors correlate with severity of prolapse.

METHODS

mRNA and protein expression of anti-apoptotic and pro-apoptotic factors in vaginal tissues from subjects and controls were determined by real-time PCR and Western blot. Severity of prolapse was staged using POP-Q criteria.

RESULTS

Differential expression of Bcl-2 family factors was observed in protein rather than in gene expression. During the secretory phase, the anti-apoptotic (Bcl-2, Bcl-xl) and pro-apoptotic protein (Bax) were upregulated in controls compared to cases (P < 0.05). The ratios of Bcl-2/Bax and Bcl-2/Bad, which determine cellular sensitivity to induction of apoptosis, were higher in controls versus cases. Higher ratios indicate reduced cellular sensitivity to apoptosis. Protein expression of Bax and Bad was higher in women with severe compared to mild prolapse (P < 0.05).

CONCLUSION

Increased expression of Bad, Bax, and decreased ratios of Bcl-2/Bax, Bcl-2/Bad suggest increased apoptotic activity or sensitivity to induction of apoptosis in vaginal tissues of women with POP.

Pituitary-ovary-spleen axis in ovulation

Leukocytes are rapidly recruited to the preovulatory ovary and play a crucial role as facilitators of ovulation and luteal formation. In this article, recent findings on leukocyte trafficking to the ovary, as well as the physiological role of leukocytes in the ovary, will be summarized and discussed. We then explore the novel hypothesis that the hypothalamus-pituitary-ovary (HPO) axis might include the spleen as a reservoir of leukocytes by summarizing recent reports on this topic, both in the fields of immunology and reproductive biology.

Intrapartum risk factors for levator trauma

OBJECTIVE

To determine intrapartum risk factors associated with levator trauma as identified by ultrasound imaging.

DESIGN

A prospective observational study.

SETTING

Antenatal clinic of a tertiary hospital between May 2005 and February 2008.

POPULATION

Nulliparous women (n=488) in their first ongoing pregnancy.

METHODS

An interview and four-dimensional translabial ultrasound was carried out between 36 and 38 weeks and again 3-4 months after delivery. Obstetric data were collected from the hospital database and/or participants' records.

MAIN OUTCOME MEASURES

Levator macrotrauma ('avulsion') and microtrauma (irreversible overdistension).

RESULTS

A total of 367 women (75%) returned for the postpartum assessment after normal vaginal delivery (n=187, 51%), vacuum (n=34, 9%), forceps (n=20, 5%) and caesarean section (n=126, 34%). Median follow up was 4.08 months (interquartile range 3.68-5.03 months). Levator avulsion was diagnosed in 32 (13%) of the women who delivered vaginally and in none of the caesarean section group regardless of indication. On multivariable regression forceps delivery was significantly associated with avulsion (P=0.01; OR 3.83; 95% CI 1.34-10.94). Using >20% peripartum increase in hiatal area on Valsalva as the cutoff, 28.5% of vaginally parous women were shown to have suffered irreversible overdistension. This was positively associated with the length of second stage (P=0.001; OR 1.01 per minute; 95% CI 1.0-1.02). Intrapartum epidural appeared to have a protective effect (P=0.03; OR 0.42; 95% CI 0.19-0.93).

CONCLUSION

Levator trauma at the time of first delivery is associated with vaginal delivery, forceps and a longer second stage. Epidural pain relief may exert a protective effect.

Transforming growth interacting factor expression in leiomyoma compared with myometrium

OBJECTIVE

To investigate the expression of transforming growth interacting factor (TGIF), a Smad transcriptional corepressor, in leiomyoma and matched myometrial tissue samples and the effect of TGIF overexpression in myometrial cells.

DESIGN

Experimental study.

SETTING

Tertiary university hospital.

PATIENT(S)

Uterine leiomyoma and myometrial tissues from 16 patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The distribution of TGIF in leiomyoma and myometrial tissues by immunohistochemistry stain, mRNA, and protein expression levels by real-time quantitative polymerase chain-reaction (QPCR) and Western blot. Transcriptional regulation of TGIF in myometrial cells with overexpressed TGIF.

RESULT(S)

Although TGIF is present in the smooth muscle cells of the leiomyoma and the myometrium, it is not found in the extracellular matrix. The TGIF mRNA and protein expressions were statistically significantly higher in the leiomyoma compared with the matched, unaffected myometrial tissues in both phases of the menstrual cycle. There were no differences in mRNA or protein expression throughout the menstrual cycle. Overexpression of TGIF protein in myometrial cells statistically significantly suppressed up-regulation of plasminogen activator inhibitor (PAI-1) induced by TGF-beta1 treatment.

CONCLUSION(S)

Expression of TGIF is increased in leiomyoma compared with myometrium. This increase in TGIF expression is not affected by endogenous ovarian hormones. Thus, TGIF is a potential repressor of TGF-beta pathways in myometrial cells.

Is lysyl oxidase-like protein-1, alpha-1 antitrypsin, and neutrophil elastase site specific in pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

We investigated whether the expression of alpha-1 antitrypsin (ATT), neutrophil elastase (NE), and lysyl oxidase-like protein 1 (LOXL-1) vary within the vagina in subjects with pelvic organ prolapse (POP).

METHODS

Biopsies were obtained from the anterior and posterior vaginal wall of 22 women with POP (> or =stage 2 by POP-Q). The subjects were grouped by the most prominent defect: cystocele, cystocele plus uterine prolapse, and rectocele. Comparative real-time PCR, Western blotting, and NE enzyme activity assay were performed.

RESULTS

The ratio of anterior and posterior vaginal wall ATT, NE, and LOXL-1 expression varied between individuals within the same defect group.

CONCLUSIONS

ATT, NE, and LOXl-1 expression was variable among different biopsy sites in the vagina. No consistent pattern was present when the subjects were grouped by the most prominent defect. We recommend careful consideration of biopsy sites in future studies on POP to enhance reproducibility of data.

Relaxin increases elastase activity and protease inhibitors in smooth muscle cells from the myometrium compared with cells from leiomyomas

We investigated the effect of relaxin on extracellular matrix remodeling in cultured myometrial compared with leiomyoma smooth muscle cells. Relaxin increases elastase activity and protease inhibitor expressions in myometrial smooth muscle cells, but no effect was observed in leiomyoma cells.

Regulation of elastolytic proteases in the mouse vagina during pregnancy, parturition, and puerperium

Recent evidence indicates that failure of elastic fiber assembly and synthesis is involved in the pathophysiology of pelvic organ prolapse in mice. It has been long been hypothesized that parturition-induced activation of proteases in the vaginal wall and its supportive tissues may contribute to pelvic organ prolapse in women. In this investigation, we determined the expression of matrix metalloproteases with elastase activity (matrix metalloproteinase [MMP] 2, MMP9, and MMP12) and their inhibitors in the vaginal wall of nonpregnant, pregnant, and postpartum mice. Data obtained using mRNA levels and enzyme activity measurements indicate that MMP2, MMP9, and 21- to 24-kDa caseinolytic serine proteases are regulated in vaginal tissues from pregnant and postpartum mice. Although suppressed during pregnancy and the early postpartum time period, MMP2 and MMP9 enzyme activities are increased after 48 h, a time when mRNA levels of protease inhibitors (tissue inhibitor of MMP2 [Timp2], cystatin C [Cst3], and alpha-1 antitrypsin [Serpina1]) are decreased. We conclude that recovery of the vaginal wall from pregnancy and parturition requires increased elastic fiber assembly and synthesis to counteract the marked increase in elastolytic activity of the postpartum vagina.

Picrosirius-polarization staining method as an efficient histopathological tool for collagenolysis detection in vesical prolapse lesions

The Picrosirius-polarization method has been indicated as a selective histochemical stain for collagen detection in tissue sections. This method can also be of value for studying collagen degradation given that, under polarized light, collagen displays birefringence due to its molecular order. The aim of this study is to highlight this staining method as an additional instrument for a rapid and excellent confirmatory diagnosis of the presence of collagenolysis in connective tissue in the vaginal wall with vesical prolapse lesion, in tissue sections. Dramatic changes in collagen morphology were found in vaginal mucosa in vesical prolapse disorder: they were weakly stained by Sirius red and under polarized light appeared as thin, pale (weakly birefringent), greenish, and with fibers more scattered, while the histoarchitecture of the organ showed a disrupted appearance. Thus, in the present study, we showed in vaginal mucosa in the vesicle prolapse that corroded collagenous framework appears as fragmentary and irregularly separated collagenous structures, that are weakly birefringent, corresponding to a molecular disorganization of these fibers caused by collagenolysis.

The role of neutrophil elastase in elastin metabolism of pelvic tissues from women with stress urinary incontinence

OBJECTIVE

Altered elastin metabolism is implicated in pelvic floor disorders. We studied neutrophil elastase (NE) and matrix metalloproteinase (MMP) activities in vaginal tissues from premenopausal women with stress urinary incontinence (SUI).

METHODS

Elastase and NE activities in vaginal tissues were assessed. Protein and mRNA expressions were determined by RT-PCR and Western blot. Total elastin and collagen contents were evaluated. To compare the relative elastolytic effect of NE and MMP-2, we used their respective antibodies to immunoprecipitate these proteins from vaginal fibroblast extracts prior to assessing elastase activity.

RESULTS

Elastase activity in vaginal wall tissues was significantly higher in the secretory compared to the proliferative phase. NE mRNA and protein expressions were similar between control and SUI tissues from the secretory phase. However, NE activity in the SUI tissues was higher compared to control tissues. The mRNA expression of alpha-1 antitrypsin (ATT) was higher in control tissues from the proliferative phase compared to those from the secretory phase, while no difference was observed in SUI tissues between either phase. Protein expression of the active form of ATT was decreased in SUI tissues compared to controls during the secretory phase. Anti-NE antibody reduced total elastase activity by 60-70%, compared to less than 20% reduction with anti-MMP-2 antibody.

CONCLUSION

During the secretory phase, elastolytic activity is increased in pelvic tissues from women with SUI, through an increase in NE activity and a concurrent decrease in ATT expression. The serine protease, NE, appears to be a more significant modulator of elastase activity compared to MMP-2.

Differences in mRNA and protein expression of small proteoglycans in vaginal wall tissue from women with and without stress urinary incontinence

BACKGROUND

To investigate changes in mRNA and protein levels of biglycan (BGN), decorin (DCN) and fibromodulin (FMOD) in vaginal wall tissue from women with stress urinary incontinence (SUI) compared to menstrual-cycle matched continent women.

METHODS

We determined mRNA expressions of BGN, DCN and FMOD by quantitative real-time PCR. They were localized in vaginal wall tissue by immunohistochemistry. We performed western blot analysis to examine protein expression.

RESULTS

BGN, DCN and FMOD co-localized with collagen and elastin in the extracellular matrix (ECM) of vaginal wall tissue from both groups. The mRNA expression of FMOD was significantly lower in cases versus controls in the proliferative phase (P = 0.03). DCN mRNA expression in cases was higher in the proliferative (P = 0.05) and secretory phases (P = 0.02) versus controls. BGN mRNA expression showed no significant differences in either phase. Protein expression of FMOD in cases was lower in the proliferative phase versus controls (six out of nine pairs), whereas DCN and BGN protein expression in the secretory phase in cases was higher (seven out of nine pairs).

CONCLUSION

BGN, DCN and FMOD expressions in vaginal wall tissue differ in women with SUI and are hormonally modulated. Differences in small proteoglycans may contribute to the altered pelvic floor connective tissues found in these women.

Increased expression of latent TGF-ß binding protein-1 and fibrillin-1 in human uterine leiomyomata

We compared latent TGF-ss binding protein-1 (LTBP-1) and fibrillin-1 (FBN-1) expression in leiomyomata and myometrium, correlated with leiomyomata size. We studied in vivo and in vitro effects of ovarian steroids using matched leiomyomata and myometrium samples from both phases of the menstrual cycle. Leiomyomata were divided into small (<or=2 cm), medium (3-5 cm) and large (>or=6 cm) groups. We validated LTBP-1 and FBN-1 expression using QPCR, western blot and immunohistochemistry. LTBP-1 and FBN-1 mRNA and protein expressions were higher in the medium-sized group compared with myometrium in the proliferative phase (P = 0.01; P = 0.01). FBN-1 mRNA expression was higher in the secretory phase (P = 0.01). LTBP-1 mRNA and protein expression was higher in the medium group compared with the small and large groups in the proliferative phase (P = 0.04; P = 0.04). No differences between groups were seen in FBN-1 expression in either phase. 17Beta-estradiol (E2) increased mRNA and protein expression of LTBP-1 and FBN-1 in cultured leiomyoma smooth muscle cells (LSMC) (P < 0.05). No change in FBN-1 and LTBP-1 expression was observed when cells were treated with E2 plus progesterone. Estrogen may be involved in LTBP-1 and FBN-1 expression in leiomyomata. Extracellular matrix metabolism may be different in medium-sized leiomyoma.

Relaxin and beta-estradiol modulate targeted matrix degradation in specific synovial joint fibrocartilages: progesterone prevents matrix loss

Relaxin, a 6-kDa polypeptide hormone, is a potent mediator of matrix turnover and contributes to the loss of collagen and glycosaminoglycans (GAGs) from reproductive tissues, including the fibrocartilaginous pubic symphysis of several species. This effect is often potentiated by β-estradiol. We postulated that relaxin and β-estradiol might similarly contribute to the enhanced degradation of matrices in fibrocartilaginous tissues from synovial joints, which may help explain the preponderance of diseases of specific fibrocartilaginous joints in women of reproductive age. The objective of this study was to compare the in vivo effects of relaxin, β-estradiol, and progesterone alone or in various combinations on GAG and collagen content of the rabbit temporomandibular joint (TMJ) disc fibrocartilage, knee meniscus fibrocartilage, knee articular cartilage, and the pubic symphysis. Sham-operated or ovariectomized female rabbits were administered β-estradiol (20 ng/kg body weight), progesterone (5 mg/kg), or saline intramuscularly. This was repeated 2 days later and followed by subcutaneous implantation of osmotic pumps containing relaxin (23.3 μg/kg) or saline. Tissues were retrieved 4 days later and analyzed for GAG and collagen. Serum relaxin levels were assayed using enzyme-linked immunosorbent assay. Relaxin administration resulted in a 30-fold significant (p < 0.0001) increase in median levels (range, approximately 38 to 58 pg/ml) of systemic relaxin. β-estradiol, relaxin, or β-estradiol + relaxin caused a significant loss of GAGs and collagen from the pubic symphysis and TMJ disc and of collagen from articular cartilage but not from the knee meniscus. Progesterone prevented relaxin- or β-estradiol-mediated loss of these molecules. The loss of GAGs and collagen caused by β-estradiol, relaxin, or β-estradiol + relaxin varied between tissues and was most prominent in pubic symphysis and TMJ disc fibrocartilages. The findings suggest that this targeted modulation of matrix loss by hormones may contribute selectively to degeneration of specific synovial joints.

A urogynecologist's view ofthe pelvic floor effects of vaginal delivery/cesarean section for the urologist

Pregnancy and parturition have been implicated in the development of pelvic floor dysfunction. These disorders include urinary incontinence, fecal incontinence, pelvic organ prolapse, and other pelvic and sexual dysfunctions. The urologist caring for women with urinary dysfunction needs to be familiar with the causes of pelvic floor dysfunction and their implications. Defects of the pelvic floor have clearly resulted from the traumatic effect of vaginal delivery. The likely mechanisms of injuries during vaginal delivery involve stretching and compression of the pudendal nerve and peripheral branches, as well as an additional tearing of muscles and connective tissue. Optimal management of labor and optimal techniques of repair of unavoidable sphincteric lacerations, ante- and postpartum pelvic floor muscle conditioning, and timely and proper indications for cesarean delivery will minimize the effect of incidental traumatic delivery.

Do extracellular matrix protein expressions change with cyclic reproductive hormones in pelvic connective tissue from women with stress urinary incontinence?

BACKGROUND

To evaluate differential expression of transforming growth factor (TGF-beta1), latent transforming factor-binding proteins (LTBP-1, LTBP-2) and elastin microfibril components (fibrillin-1 and fibrillin-2) in vaginal tissue from women with stress urinary incontinence (SUI).

METHODS

In this case-control study, vaginal tissue from women in both phases of the menstrual cycle was obtained. Messenger RNA (mRNA) expressions of LTBP-1, LTBP-2, fibrillin-1, fibrillin-2 and TGF-beta1 were determined by relative real-time quantification PCR. Tissue localization was analysed by immunohistochemistry, and semiquantitative protein expression was evaluated by Western blot analysis.

RESULTS

Vaginal wall fibroblasts synthesized all proteins tested. LTBP-1, LTBP-2 and TGF-beta1 co-localized with elastin microfibrils, fibrillin-1 and fibrillin-2 in the extracellular matrix. LTBP-1 mRNA and protein expressions were higher in control versus women affected with SUI in the proliferative phase (P = 0.04), while in the secretory phase, mRNA expression in cases was higher (P = 0.04). Fibrillin-1 mRNA was higher in women affected by SUI versus controls in both phases, but no statistical differences in fibrillin-1 protein expression were observed between the two groups in either phase. LTBP-2 and TGF-beta1 mRNA expressions showed the same trends as LTBP-1.

CONCLUSION

LTBP-1, LTBP-2, TGF-beta1, fibrillin-1, and fibrillin-2 expressions are hormonally regulated in vaginal wall fibroblasts and differ in women affected by SUI when compared to controls. These data suggest a mechanism to regulate TGF-beta1 activity in pelvic connective tissue.

Relaxin: antifibrotic properties and effects in models of disease

Fibrosis (progressive scarring) is a leading cause of organ failure worldwide and causes loss of organ function when normal tissue is replaced with excess connective tissue. Several organs are prone to this process regardless of etiology. The pleiotropic hormone, relaxin, is emerging as a novel antifibrotic therapy. Relaxin has been shown to limit collagen production and reorganization, while stimulating increased collagen degradation. It not only prevents fibrogenesis, but also reduces established scarring. This review summarizes (1) the levels at which relaxin inhibits collagen production and existing collagen overexpression in induced models of fibrosis, and (2) the collagen-related phenotypes of relaxin- and LGR7-deficient mice. Recent studies on relaxin-deficient mice have established relaxin as an important, naturally occurring regulator of collagen turnover and provide new insights into the therapeutic potential of relaxin.