Menstrual phase-dependent gene expression differences in periurethral vaginal tissue from women with stress incontinence

Cytokine modulation in pelvic organ prolapse and urinary incontinence: from molecular insights to therapeutic targets

Pelvic organ prolapse (POP) and urinary incontinence (UI) are common disorders that significantly impact women's quality of life. Studies have demonstrated that cytokines, including pro- and anti-inflammatory immune mediators, play a role in illness genesis and progression. Research on the inflammatory milieu of the pelvic floor has shown that POP patients have increased inflammation in vaginal tissues. This evidence revealed that significant changes in the inflammatory milieu of the pelvic floor are an aspect of the pathogenesis of POP. POP patients exhibit increased levels of inflammatory cytokines (IL-1, TNF, IFN, and others) in the front vaginal wall, which may alter collagen metabolism and contribute to POP. Studies indicate that cytokines such as IL-6, IL-10, and TGF, which are involved in inflammation, remodelling, and repair, have dual effects on POP and UI. They can promote tissue healing and regeneration but also exacerbate inflammation and fibrosis, contributing to the progression of these conditions. Understanding the dual roles of these cytokines could help us improve the vaginal microenvironment of women and treat POP and UI. Given the considerable changes in these cytokines, this review addresses studies published between 2000 and 2024 on the molecular mechanisms by which pro- and anti-inflammatory cytokines affect women with POP and UI. Furthermore, we explain novel therapeutic strategies for cytokine regulation, emphasizing the possibility of personalized treatments that address the underlying inflammatory milieu of the vagina in POP and UI patients. This thorough analysis aims to establish a foundation for future research and clinical applications, ultimately improving patient outcomes via designed cytokine-based therapies.

Scaffold-based tissue engineering strategies for urethral repair and reconstruction

Urethral strictures are common in urology; however, the reconstruction of long urethral strictures remains challenging. There are still unavoidable limitations in the clinical application of grafts for urethral injuries, which has facilitated the advancement of urethral tissue engineering. Tissue-engineered urethral scaffolds that combine cells or bioactive factors with a biomaterial to mimic the native microenvironment of the urethra, offer a promising approach to urethral reconstruction. Despite the recent rapid development of tissue engineering materials and techniques, a consensus on the optimal strategy for urethral repair and reconstruction is still lacking. This review aims to collect the achievements of urethral tissue engineering in recent years and to categorize and summarize them to shed new light on their design. Finally, we visualize several important future directions for urethral repair and reconstruction.

Genetics of Female Pelvic Organ Prolapse: Up to Date

Pelvic organ prolapse (POP) is a benign disease characterized by the descent of pelvic organs due to weakened pelvic floor muscles and fascial tissues. Primarily affecting elderly women, POP can lead to various urinary and gastrointestinal tract symptoms, significantly impacting their quality of life. The pathogenesis of POP predominantly involves nerve-muscle damage and disorders in the extracellular matrix metabolism within the pelvic floor. Recent studies have indicated that genetic factors may play a crucial role in this condition. Focusing on linkage analyses, single-nucleotide polymorphisms, genome-wide association studies, and whole exome sequencing studies, this review consolidates current research on the genetic predisposition to POP. Advances in epigenetics are also summarized and highlighted, aiming to provide theoretical recommendations for risk assessments, diagnoses, and the personalized treatment for patients with POP.

Cell-Based Therapy for Urethral Regeneration: A Narrative Review and Future Perspectives

Urethral stricture is a common urological disease that seriously affects quality of life. Urethroplasty with grafts is the primary treatment, but the autografts used in clinical practice have unavoidable disadvantages, which have contributed to the development of urethral tissue engineering. Using various types of seed cells in combination with biomaterials to construct a tissue-engineered urethra provides a new treatment method to repair long-segment urethral strictures. To date, various cell types have been explored and applied in the field of urethral regeneration. However, no optimal strategy for the source, selection, and application conditions of the cells is available. This review systematically summarizes the use of various cell types in urethral regeneration and their characteristics in recent years and discusses possible future directions of cell-based therapies.

Reduced Dehydroepiandrosterone-Sulfate Levels in the Mid-Luteal Subphase of the Menstrual Cycle: Implications to Women's Health Research

The regulation of DHEA-sulfate by steroid sulfotransferase (SULT) and steryl-sulfatase (STS) enzymes is a vital process for the downstream formation of many steroid hormones. DHEA-sulfate is the most abundant steroid hormone in the human body; thus, DHEA-sulfate and its hydrolyzed form, DHEA, continue to be evaluated in numerous studies, given their importance to human health. Yet, a basic question of relevance to the reproductive-age female population-whether the two steroid hormones vary across the menstrual cycle-has not been addressed. We applied a validated, multi-step protocol, involving realignment and imputation of study data to early follicular, mid-late follicular, periovulatory, and early, mid-, and late luteal subphases of the menstrual cycle, and analyzed DHEA-sulfate and DHEA serum concentrations using ultraperformance liquid chromatography tandem mass spectrometry. DHEA-sulfate levels started to decrease in the early luteal, significantly dropped in the mid-luteal, and returned to basal levels by the late luteal subphase. DHEA, however, did not vary across the menstrual cycle. The present study deep-mapped trajectories of DHEA and DHEA-sulfate across the entire menstrual cycle, demonstrating a significant decrease in DHEA-sulfate in the mid-luteal subphase. These findings are relevant to the active area of research examining associations between DHEA-sulfate levels and various disease states.

Molecular Processes in Stress Urinary Incontinence: A Systematic Review of Human and Animal Studies

Stress urinary incontinence (SUI) is a common and burdensome condition. Because of the large knowledge gap around the molecular processes involved in its pathophysiology, the aim of this review was to provide a systematic overview of genetic variants, gene and protein expression changes related to SUI in human and animal studies. On 5 January 2021, a systematic search was performed in Pubmed, Embase, Web of Science, and the Cochrane library. The screening process and quality assessment were performed in duplicate, using predefined inclusion criteria and different quality assessment tools for human and animal studies respectively. The extracted data were grouped in themes per outcome measure, according to their functions in cellular processes, and synthesized in a narrative review. Finally, 107 studies were included, of which 35 used animal models (rats and mice). Resulting from the most examined processes, the evidence suggests that SUI is associated with altered extracellular matrix metabolism, estrogen receptors, oxidative stress, apoptosis, inflammation, neurodegenerative processes, and muscle cell differentiation and contractility. Due to heterogeneity in the studies (e.g., in examined tissues), the precise contribution of the associated genes and proteins in relation to SUI pathophysiology remained unclear. Future research should focus on possible contributors to these alterations.

The role of transforming growth factor-ß (TGF-ß1) in postmenopausal women with pelvic organ prolapse: An immunohistochemical study

Objective

Aim of the study was to investigate the expression of transforming growth factor-β1 (TGF-β1), a key regulator of the extracellular matrix composition, in the uterosacral ligaments (USLs) of women with pelvic organ prolapse (POP) compared with controls. We hypothesized that the expression pattern of TGF-β1 differs between postmenopausal women with or without POP.

Methods

Under ethical approval, USL samples were obtained from postmenopausal women undergoing vaginal hysterectomy for stage two or greater pelvic organ prolapse (cases, n = 70) and from postmenopausal women without pelvic organ prolapse undergoing vaginal hysterectomy for benign indications (controls, n = 30). Immunohistochemical staining was performed from paraffin embedded tissue using anti-TGF-β1 antibodies. The expression of TGF-β1 was evaluated by the pathologist, who was blinded to all clinical data.

Results

The expression of TGF-ß1 was similar in patients with symptomatic POP (89 % positive) and in controls (90 % positive) without any signs of prolapse (p = 0.091). Age-adjusted analysis did not significantly alter these results. Regarding POP-Q stages, TGF-ß1 was significantly more frequently expressed in severe prolapse cases compared to moderate/mild cases (POP-Q stage IV versus POP-Q stage II and III; p = 0.001). No significant association could be detected between TGF-ß1 expression and age, BMI and parity in cases with POP (p > 0.05). As published previously, advanced patients’ age as well as early menopausal age remained independent risk factors associated with POP in multiple logistic regression analysis (p = 0.001; p = 0.02).

Conclusion

Although our study detected POP-Q stage related alterations in USL composition and TGF-ß1 expression, there was no significant difference in the expression of TGF-β1 in cases with or without prolapse.

LncRNA and mRNA Expression Profiling in the Periurethral Vaginal Wall Tissues of Postmenopausal Women with Stress Urinary Incontinence

Stress urinary incontinence (SUI) is one of the major pelvic floor disorders affecting postmenopausal women. To investigate the lncRNA and mRNA expression profiling of SUI in postmenopausal women, we used a microarray analysis to examine the differentially expressed long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs) in the periurethral vaginal wall of postmenopausal women with SUI. A total of 8840 lncRNAs and 7102 mRNAs were dysregulated in the two groups (absolute fold change ≥ 2 and P < 0.05). The expression levels of five randomly selected lncRNAs and mRNAs were validated by quantitative real-time PCR. A functional analysis revealed that several lncRNAs are involved in the lysosome pathway associated with extracellular matrix (ECM) remodeling. In addition, we also found several mRNAs involved in fibroblast pseudopodia formation, fibroblast growth, and the regulation of smooth muscle cell differentiation in the urinary tract. Our study offers essential data regarding differentially expressed lncRNAs and mRNAs and may provide new potential candidates for the study of SUI.

The role of tenascin-X in the uterosacral ligaments of postmenopausal women with pelvic organ prolapse: an immunohistochemical study

INTRODUCTION AND HYPOTHESIS

Abnormalities of connective tissue structure or its repair mechanism may predispose women to pelvic organ prolapse (POP). We hypothesized that the expression of tenascin-X in the uterosacral ligament of postmenopausal women with symptomatic POP is increased compared with postmenopausal women without POP. Furthermore, we identified clinical risk factors associated with POP in our study population.

METHODS

We conducted a retrospective case-control study in which 33 postmenopausal women with symptomatic POP ≥ pelvic organ prolapse quantification system (POP-Q) stage II were matched with 33 postmenopausal women without POP. Studied tissue specimens were taken from hysterectomy specimens, and tenascin-X expression was investigated by immunohistochemistry. The immunohistochemical profile of the uterosacral connective tissue of cases and controls was compared.

RESULTS

Tenascin-X was expressed in 94% of POP cases and in 91% of controls. Our study failed to show any statistically significant differences in tenascin-X expression between women with and without POP (p = 0.64). However, tenascin-X was significantly more expressed in cases with severe prolapse (POP-Q stage IV) compared with moderate prolapse stages (POP-Q stage II and III) (p = 0.001). Advanced patient age as well as early menopausal age remained independent risk factors associated with POP in multiple logistic regression analysis (p = 0.001).

CONCLUSION

No difference could be demonstrated between tenascin-X expression in patients with or without POP. Tenascin-X does not seem to play a major role in the pathogenesis of POP in postmenopausal women.

MicroRNA-29 facilitates transplantation of bone marrow-derived mesenchymal stem cells to alleviate pelvic floor dysfunction by repressing elastin

Background

Pelvic floor dysfunction (PFD) is a condition affecting many women worldwide, with symptoms including stress urinary incontinence (SUI) and pelvic organ prolapse (POP). We have previously demonstrated stable elastin-expressing bone marrow-derived mesenchymal stem cells (BMSCs) attenuated PFD in rats, and aim to further study the effect of microRNA-29a-3p regulation on elastin expression and efficacy of BMSC transplantation therapy.

Methods

We inhibited endogenous microRNA-29a-3p in BMSCs and investigated its effect on elastin expression by RT-PCR and Western blot. MicroRNA-29-inhibited BMSCs were then transplanted into PFD rats, accompanied by sustained release of bFGF using formulated bFGF in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP), followed by evaluation of urodynamic tests.

Results

MicroRNA-29a-3p inhibition resulted in upregulated expression and secretion of elastin in in vitro culture of BMSCs. After co-injection with PLGA-loaded bFGF NP into the PFD rats in vivo, microRNA-29a-3p-inhibited BMSCs significantly improved the urodynamic test results.

Conclusions

Our multidisciplinary study, combining microRNA biology, genetically engineered BMSCs, and nanoparticle technology, provides an excellent stem cell-based therapy for repairing connective tissues and treating PFD.

Transplantation of bone marrow-derived mesenchymal stem cells expressing elastin alleviates pelvic floor dysfunction

Background

Pelvic floor dysfunction (PFD) is a group of clinical conditions including stress urinary incontinence (SUI) and pelvic organ prolapse (POP). The abnormality of collagen and elastin metabolism in pelvic connective tissues is implicated in SUI and POP.

Methods

To reconstitute the connective tissues with normal distribution of collagen and elastin, we transduced elastin to bone marrow-derived mesenchymal stem cells (BMSC). Elastin-expressing BMSCs were then differentiated to fibroblasts using bFGF, which produced collagen and elastin. To achieve the sustained release of bFGF, we formulated bFGF in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP).

Results

In an in vitro cell culture system of 7 days, when no additional bFGF was administrated, the initial PLGA-loaded bFGF NP induced prolonged production of collagen and elastin from elastin-expressing BMSCs. In vivo, co-injection of PLGA-loaded bFGF NP and elastin-expressing BMSCs into the PFD rats significantly improved the outcome of urodynamic tests. Together, these results provided an efficient model of connective tissue engineering using BMSC and injectable PLGA-loaded growth factors.

Conclusions

Our results provided the first instance of a multidisciplinary approach, combining both stem cell and nanoparticle technologies, for the treatment of PFD.

Differential expression of microRNAs in periurethral vaginal wall tissues of postmenopausal women with and without stress urinary incontinence

OBJECTIVE

The aims of this study were to investigate microRNA (miRNA) expression profiles in the periurethral vaginal wall tissues of postmenopausal women with and without stress urinary incontinence (SUI) and to explore the putative target genes associated with SUI via miRNA-messenger RNA (mRNA) pair prediction.

METHODS

Periurethral vaginal wall tissues of postmenopausal women with SUI (n = 13) and matched continent postmenopausal women (n = 13) were collected during transvaginal surgical operation. Total RNAs were extracted and miRNAs were profiled by TaqMan Array Human MicroRNA assays in three case-control pairs. TargetScanS, PicTar, and miRanda were used to obtain the putative miRNA-mRNA pairs based on sequence data, and three pairs were predicated. The relative expression levels of miRNAs in predicated miRNA-mRNA pairs were quantified in 10 other case-control pairs by real-time polymerase chain reaction. The expression levels of mRNAs and corresponding proteins were estimated via real-time polymerase chain reaction and Western blot analysis.

RESULTS

Twelve miRNAs were identified to be differentially expressed between two groups: the significantly up-regulated let-7a, miR-101#, miR-125b-2#, miR-190b, and miR-892b, and the down-regulated miR-124, miR-330-3p, miR-485-3p, miR-517b, miR-523, miR-589, and miR-93#. Moreover, three miRNA-mRNA pairs of interest were established via computational algorithms: miR-124 and growth factor receptor-bound protein 2; miR-330-3p and bicaudal D homolog 2; and miR-93# and signal transducer and activator of transcription 3. The expression levels of the three miRNAs were quantified, and a reduction in SUI was revealed. On the other hand, increased expression levels of predicated mRNAs and their protein products were detected.

CONCLUSIONS

This study reports the differential expression of 12 miRNAs in SUI and predicates three miRNA-mRNA pairs. Interestingly, all three predicated target genes are associated with neurodegenerative conditions, indicating the potential significance of neurodegenerative mechanisms in the etiology of SUI.

The role of synthetic and biologic materials in the treatment of pelvic organ prolapse

Pelvic organ prolapse is a significant medical problem that poses a diagnostic and management dilemma. These diseases cause serious morbidity in those affected and treatment is sought for relief of pelvic pain, rectal bleeding, chronic constipation, obstructed defecation, and fecal incontinence. Numerous procedures have been proposed to treat these conditions; however, the search continues as colorectal surgeons attempt to find the procedure that would optimally treat these conditions. The use of prosthetics in the repair of pelvic organ prolapse has become prevalent as the benefits of their use are realized. While advances in biologic mesh and new surgical techniques promise improved functional outcomes with decreased complication rates without de novo symptoms, the debate concerning the best prosthetic material, synthetic or biologic, remains controversial. Furthermore, laparoscopic ventral mesh rectopexy has emerged as a procedure that could potentially fill this role and is rapidly becoming the procedure of choice for the surgical treatment of pelvic organ prolapse.

Demands and properties of alloplastic implants for the treatment of stress urinary incontinence

Surgical treatment of stress urinary incontinence changed dramatically with the introduction of the tension-free vaginal tape. Owing to its high efficacy and minimal patient discomfort this new minimally invasive procedure quickly obtained widespread acceptance and superseded the abdominal colposuspension as the gold standard. In the course of success of the original method a number of tension-free vaginal tapes flooded the market, varying in approach and material. These variations may strongly influence the safety, efficacy and long-term results of tension-free vaginal tape and its major modification, the transobturator technique. Therefore, it is the aim of this review to closely illuminate available materials and complications associated with this procedure. An extensive Medline search of the published literature up until 2006 on the subject of stress urinary incontinence was carried out. All sources identified were reviewed with particular attention to the method applied, the properties of the mesh materials and clinical complications. Apart from several technical variations, there are marked differences between the different vaginal sling materials, ranging from absorbable collagens over polypropylene to allografts. Although performed globally in substantial and increasing numbers, minimally invasive techniques for the surgical treatment of stress urinary incontinence are lacking sufficient safety data.

Expression of extracellular matrix-remodeling proteins is altered in vaginal tissue of premenopausal women with severe pelvic organ prolapse

AIM

The molecular etiology of pelvic organ prolapse (POP) is complex and not well understood. We compared the expression/activity of extracellular matrix (ECM)-processing (procollagen I N-proteinase/ a disintegrin and metalloproteinase with thrombospondin motifs [ADAMTS]-2,-3,-14) and ECM-degrading (matrix metalloproteinase [MMP]-1, -2, -7, -8, -9, -12) enzymes and their natural tissue inhibitors (tissue inhibitors of metalloproteinase [TIMP]-1,-2,-3,-4) in vaginal tissues from premenopausal women with advanced POP (POP-Q stage ≥ 3) and asymptomatic controls (POP-Q = 0).

STUDY DESIGN

We sampled the anterior vaginal wall of 36 premenopausal women (17 patients with POP and 19 controls) undergoing total hysterectomy. Exclusion criteria include steroid therapy, malignancy, previous pelvic surgery, and connective tissue diseases. Total RNAs and proteins were quantified by real-time polymerase chain reaction, immunoblotting, and Luminex assay; MMPs activity was analyzed by zymography and tissue localization by immunohistochemistry.

RESULTS

The MMP-2 gelatinase activity as well as expression of 58-kDa isoform of ADAMTS-2 was upregulated in patients with POP, irrespective of menstrual phase status, secretory or proliferative, when compared to controls (P < .05). The TIMP-1-4 gene and TIMP-1 protein expression were significantly (P < .05) reduced, whereas protein expression of MMP-12 (pro and active forms) was significantly increased in vaginal biopsies of patients with POP in the proliferative phase of the menstrual cycle compared to corresponding controls. Analyses of MMP-12, TIMP-1, and ADAMTS-2 tissue immunostaining indicate similar localization in the vaginal specimens from control and patients with POP.

CONCLUSION

Expression of ECM-remodeling proteins is altered in the vagina of premenopausal patients with severe POP. We speculate that dysregulation of MMP/TIMP complexes and ADAMTS-2 proteins may cause connective tissue defects, which result in weakened vaginal wall support and POP development.

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.

Is tissue engineering and biomaterials the future for lower urinary tract dysfunction (LUTD)/pelvic organ prolapse (POP)?

The fields of tissue engineering and regenerative medicine have seen major advances over the span of the past two decades, with biomaterials playing a central role. Although the term "regenerative medicine" has been applied to encompass most fields of medicine, in fact urology has been one of the most progressive. Many urological applications have been investigated over the past decades, with the culmination of these technologies in the introduction of the first laboratory-produced organ to be placed in a human body.1 With the quality of life issues associated with urinary incontinence, there is a strong driver to identify and introduce new technologies and the potential exists for further major advancements from regenerative medicine approaches using biomaterials, cells or a combination of both. A central question is why use biomaterials? The answer rests on the need to make up for inadequate or lack of autologous tissue, to decrease morbidity and to improve long-term efficacy. Thus, the ideal biomaterial needs to meet the following criteria: (1) Provide mechanical and structural support, (2) Maintain compliance and be biocompatible with surrounding tissues, and (3) Be "fit for purpose" by meeting specific application needs ranging from static support to bioactive cell signaling. In essence, this represents a wide range of biomaterials with a spectrum of potential applications, from use as a supportive or bulking implant alone, to implanted biomaterials that promote integration and eventual replacement by infiltrating host cells, or scaffolds pre-seeded with cells prior to implant. In this review we shall discuss the structural versus the integrative uses of biomaterials by referring to two key areas in urology of (1) pelvic organ support for prolapse and stress urinary incontinence, and (2) bladder replacement/augmentation.

Alterations in connective tissue metabolism in stress incontinence and prolapse

PURPOSE

We describe current knowledge about collagen/elastin and extracellular matrix metabolism in the genitourinary tract with special emphasis on stress urinary incontinence. We also explored the influence of genetics and reproductive hormones on extracellular matrix metabolism.

MATERIALS AND METHODS

We performed a MEDLINE® search from 1995 to February 2011 using the key words stress urinary incontinence, pelvic organ prolapse, extracellular matrix, collagen, elastin, matrix metalloproteinase, collagenase, tissue inhibitors of matrix metalloproteinase, elastin metabolism, elastase, connective tissue, supportive tissue, mechanical stress, biomechanical properties, selective estrogen receptor modulators, transforming growth factor-β and wound healing.

RESULTS

The literature searched produced data on 4 areas of significance for extracellular matrix metabolism in patients with stress urinary incontinence and prolapse, including collagen, elastin and transforming growth factor-β. Data on collagen metabolism continue to support the hypothesis of increased turnover involving matrix metalloproteinases and serine proteases in pelvic tissues of affected individuals. Elastin metabolism studies suggest increased degradation but also abnormal elastin fiber synthesis. Epidemiological data indicate a genetic predisposition to abnormal extracellular matrix in affected individuals while human tissue and animal models reveal differential expression of candidate genes involved in structural proteins. Transforming growth factor-β pathways have been documented to be involved in stress urinary incontinence in human tissues and animal models. Finally, these extracellular matrix metabolisms are modulated by reproductive hormones and selective estrogen receptor modulators.

CONCLUSIONS

Pelvic tissue from women with stress urinary incontinence and pelvic organ prolapse show a genetic predisposition to abnormal extracellular matrix remodeling, which is modulated by reproductive hormones, trauma, mechanical stress load and aging. This progressive remodeling contributes to stress urinary incontinence/pelvic organ prolapse by altering normal tissue architecture and mechanical properties.

Genetics of pelvic organ prolapse: crossing the bridge between bench and bedside in urogynecologic research

An increasing number of scientists have studied the molecular and biochemical basis of pelvic organ prolapse (POP). The extracellular matrix content of the pelvic floor is the major focus of those investigations and pointed for potential molecular markers of the dysfunction. The identification of women predisposed to develop POP would help in the patients' management and care. This article includes a critical analysis of the literature up to now; discusses implications for future research and the role of the genetics in POP.

Changes of glycoprotein and collagen immunolocalization in the uterine artery wall of postmenopausal women with and without pelvic organ prolapse

Pelvic organ prolapse (POP) is accompanied by an altered composition of the extracellular matrix (ECM). However, it is unclear whether the changed ECM is the cause or the consequence of POP, as stretching of the tissue may have an effect on the composition of the ECM. To address this question, we analyzed the connective tissues of the uterine artery wall of postmenopausal women with and without POP. The uterine artery wall is stretched in patients with POP, but this stretching is unlikely to cause the POP. Twenty-one women (13 with POP and 8 without POP) hospitalized for hysterectomy were included in this study. Tissue samples from the uterine artery were analyzed for collagen (types I, III, IV, V and VI) and other ECM proteins (fibronectin, laminin, tenascin, vitronectin and elastin) using immunofluorescence microscopy. Results revealed that uterine artery samples of women with prolapse showed a significantly weaker immunoreactivity to type VI collagen, vitronectin and elastin and a stronger immunostaining for type III collagen and tenascin as compared to control samples. Our results suggest that the ECM may be altered in response to mechanical stretch. Changes in the ECM composition as observed in POP may not necessarily be the reason for the development of pelvic floor relaxation in postmenopausal women.

Microarray analysis of differentially expressed genes in vaginal tissues in postmenopausal women. The role of stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

This study aimed to explore gene expression and their regulatory mechanisms in etiology of stress urinary incontinence (SUI).

METHODS

Tissue samples were taken from the paraurethral vaginal wall from three pairs of postmenopausal, age/body mass index/parity-matched SUI, and continent women and subjected to microarray analysis using the Affymetrix GeneChip® Human Genome U133 Plus 2.0 oligonucleotide chip set. The significantly differentially expressed genes and their protein expression were confirmed by quantitative PCR and Western blot.

RESULTS

Seventy-five differentially expressed genes were listed; 31 genes were upregulated in SUI group, while 44 were downregulated. Gene metabolic pathway analysis showed that solutable N-ethylmaleimide-sensitive factor attachment protein receptor signaling pathway and neurodegenerative disorder pathway were the most predominant.

CONCLUSIONS

Apolipoprotein E, growth factor receptor-bound protein 2, Golgi SNAP receptor complex member 1, and glucosidase, beta, acid may play a neurodegenerative role in SUI development.

Peripheral blood mononuclear cell gene array profiles in patients with overactive bladder

OBJECTIVES

To investigate the utility of using peripheral blood mononuclear cells (PBMC) as a marker for patients with overactive bladder (OAB). Patients with OAB may suffer from varying degrees of symptoms such as frequency, urgency, nocturia, and incontinence; however, there is no definitive test for OAB at this time. Questionnaires may provide useful tools for screening patients for OAB but often clinicians may need to rely on more invasive procedures to confirm the diagnosis. We have previously demonstrated that PBMC can provide a reporter function in solid organ retroperitoneal disease.

METHODS

Twenty-one patients were assessed for OAB. PBMC was obtained from whole blood of the patients, and RNA was subjected to microarray gene chip analysis.

RESULTS

Microarray analysis revealed that 16 genes were differentially regulated (8 upregulated and 8 downregulated) in all patients with OAB in comparison with healthy controls. A sex-based analysis demonstrated 74 genes that were differentially regulated in males (25 upregulated and 49 downregulated), and 30 in females (13 upregulated and 17 downregulated). Of these platelet-derived growth factors, microfibrillar-associated protein and tropomyosin were downregulated in all sets that were analyzed.

CONCLUSIONS

Microarray analysis revealed many genes that were differentially regulated in PBMC from OAB patients, including regulatory elements and genes encoding structural proteins, which may be important in regulating structural integrity of the bladder and supporting tissues. These data suggest that PBMC can provide a reporter function for patients with OAB and may serve as a diagnostic marker and elucidate genes involved in this condition.

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.

The contractile properties of vaginal myofibroblasts: is the myofibroblasts contraction force test a valuable indication of future prolapse development?

Using a specific myofibroblast contraction test, we try to predict future utero-vaginal prolapse development in young primiparae women. We compare myofibroblast cultures of the vaginal wall in primiparae women (group 1), young multiparae women (group 2) and older multiparae women (group 3) who were operated on for severe utero-vaginal prolapse. A myofibroblast-mediated collagen gel contraction assay determined a contraction factor that was compared in the three groups of women. The myofibroblasts contraction factor after 24 and 48 hours was significantly higher in group 1 women (2.4 +/- 0.6/4.4 +/- 1.9) compared to group 2 (1.6 +/- 0.3/ 1.8 +/- 0.1) andgroup 3 (1.6 +/- 0.3/1.8 +/- 0.3), but showed no differences in group 1 women without (2.1 +/- 0.5/3.5 +/- 1.9) and with (2.7 +/- 0.6/5.1 +/- 1.7) cystocoele. Vaginal myofibroblasts of young women show better contraction forces than young women with severe utero-vaginal prolapse. The latter have a myofibroblast contraction factor similar to those of older post-menopausal women operated for the same condition.

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.

Changes of collagen type III and decorin in paraurethral connective tissue from women with stress urinary incontinence and prolapse

Thirteen premenopausal women with stress urinary incontinence (SUI), 6 with SUI and prolapse, 9 with prolapse, and 19 without prolapse were enrolled to observe the content change of collagen type III and the expression of decorin mRNA in paraurethral connective tissues. Collagen type III from transvaginal biopsies was assayed by immunohistochemical staining and decorin mRNA was detected by real-time PCR. Premenopausal women with SUI had a significantly decreased level of collagen type III. Decorin mRNA expression was significantly increased in both premenopausal SUI+prolapse group and premenopausal prolapse group reflected by the decrease of DeltaCt value compared to their corresponding controls. The results suggest that a high level of decorin mRNA might be associated with the reduced content of collagen type III, resulting in a less flexible form of extracellular matrix in the connective tissue in SUI and prolapse patients.

Sequence variant in the laminin gamma1 (LAMC1) gene associated with familial pelvic organ prolapse

Pelvic organ prolapse is a common condition, affecting up to a third of women throughout their lifetime. Genetic factors are believed to account for about 30% of the incidence, and are the least understood component of the disorder. Familial cases, particularly those in which prolapse manifests in young women, are especially valuable in the effort to find the genes involved. We recently reported autosomal dominant transmission as the most likely mode of inheritance, based on a collection of families with high incidence of prolapse. Of greatest interest was a family in which three generations of female relatives suffered from prolapse at a very young age. A genome-wide linkage scan performed using the Affymetrix GeneChip Human mapping 10K array identified ten regions with a LOD score of 1.5, the maximum possible for this family. Candidate genes within those regions were analyzed for expression in vaginal tissue by RT-PCR. Of the genes confirmed to be expressed, LAMC1 was further evaluated by sequencing and select single nucleotide polymorphism (SNP) genotyping for causative sequence variants in affected family members. We identified one such SNP, rs10911193. The rare T variant segregating with the condition is present at a frequency of 4.9% in the general population and 22% among probands from our cohort of families. It affects the binding site for NFIL3, a transcription factor that we verified to be co-expressed in vaginal tissue. Altogether these data suggest that a polymorphism in the promoter of LAMC1 may increase the susceptibility to early-onset pelvic organ prolapse.

Microarray analysis of differentially expressed genes in vaginal tissues from women with stress urinary incontinence compared with asymptomatic women

BACKGROUND

The pathophysiology of pelvic floor dysfunction resulting in stress urinary incontinence (SUI) in women is complex. Evidence suggests that there is also a genetic predisposition towards SUI. We sought to identify differentially expressed genes involved in extracellular matrix (ECM) metabolism in vaginal tissues from women with SUI in the secretory phase of menses compared with asymptomatic women.

METHODS

Tissue samples were taken from the periurethral vaginal wall of five pairs of premenopausal, age-matched SUI and continent women and subjected to microarray analysis using the GeneChip Human Genome U133 oligonucleotide chip set.

RESULTS

Extensive statistical analyses generated a list of 79 differentially expressed genes. Elafin, keratin 16, collagen type XVII and plakophilin 1 were consistently identified as up-regulated ECM genes. Elafin, a serine protease inhibitor involved in the elastin degradation pathway and wound healing, was expressed in pelvic fibroblasts and confirmed by Western blot, quantitative competitive PCR and immunofluorescence cell staining.

CONCLUSIONS

Genes involved in elastin metabolism were differentially expressed in vaginal tissue from women with SUI, suggesting that elastin remodelling may be important in the molecular aetiology of SUI.

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

OBJECTIVE

The purpose of this study was to investigate the effect of relaxin on extracellular matrix protein expression in pelvic fibroblasts that were cultured from women with stress urinary incontinence compared with asymptomatic control subjects.

STUDY DESIGN

Periurethral vaginal wall fibroblasts from premenopausal women with stress urinary incontinence and continent women (in both the proliferative and secretory phase of the menstrual cycle) were stimulated with increasing concentrations of relaxin (0-500 ng/mL). The supernatant was sampled for matrix metalloproteinase-2 and -9 by zymography. Tissue inhibitors of metalloproteinase-1 and -2 and alpha-1 antitrypsin were evaluated with Western blot. Total elastase activity was measured by generation of free amino groups from succinylated elastin. Increasing concentrations of alpha-1 antitrypsin were added to cell lysate to evaluate total elastase activity inhibition.

RESULTS

Proliferative-phase stress urinary incontinence fibroblasts demonstrated an increase in matrix metalloproteinase-2 and no change in matrix metalloproteinase-9 and tissue inhibitors of metalloproteinase-1 and -2 expressions with increasing relaxin concentrations. Cells from control subjects showed increased expression of matrix metalloproteinase-2 and -9, but no change in tissue inhibitors of metalloproteinases. Secretory-phase stress urinary incontinence fibroblasts showed no response in matrix metalloproteinase or tissue inhibitors of metalloproteinase expressions with relaxin stimulation. Secretory-phase control fibroblasts reacted by increasing matrix metalloproteinase-2 and -9 and tissue inhibitors of metalloproteinase-2. With respect to total elastase activity and alpha-1 antitrypsin expression, increasing doses of relaxin appear to increase elastolytic activity in stress urinary incontinence cells by decreasing the expression of alpha-1 antitrypsin in proliferative phase cells or increasing the total elastase activity in secretory phase cells. Fibroblast total elastase activity was inhibited by increasing concentrations of alpha-1 antitrypsin.

CONCLUSION

Elastase activity appears to be increased in relaxin-stimulated stress urinary incontinence fibroblasts by either decreased inhibitor (alpha-1 antitrypsin) production or increased elastase activity.

Estrogen increases collagen I and III mRNA expression in the pelvic support tissues of the rhesus macaque

OBJECTIVE

Our aim was to study the effect of estradiol and raloxifene on collagen synthesis, by measuring the expression collagen I and III mRNA.

STUDY DESIGN

Nineteen nulliparous young adult rhesus macaques underwent oophorectomy and were treated for 5 months with estradiol alone, raloxifene, or no hormone. Tissue samples were acquired from the lateral vaginal wall, and included the paravaginal attachment and levator ani muscle. Expression of mRNA for collagen I and III was measured by in situ hybridization.

RESULTS

Estradiol increased mRNA for collagen I and III compared with no hormone and raloxifene treatment (ANOVA, P < .05). Collagen mRNA was localized to fibroblasts in the vaginal connective tissue and the connective tissue investments of striated muscle. Collagen mRNA was not expressed in epithelial, smooth, and striated muscle cells.

CONCLUSION

Estrogen, but not raloxifene, increases collagen gene transcription and indicates stimulation of collagen synthesis in pelvic floor connective tissues.

The expression and function of the endothelin system in contractile properties of vaginal myofibroblasts of women with uterovaginal prolapse

OBJECTIVE

The endothelin-1 system regulates (myo)fibroblast contraction in wound healing. Our aim was to determine endothelin-1 system expression and function in contractile properties of vaginal myofibroblasts of women with uterovaginal prolapse.

STUDY DESIGN

Cultures of alpha-smooth muscle actin-positive myofibroblasts that were established at the time of repair surgery for prolapse (n = 30; mean age, 56 +/- 14 years) were analyzed and compared for their expression of the endothelin-1 system and contractile properties to myofibroblasts from primiparous women.

RESULTS

Myofibroblasts expressed the complete endothelin system but did not secrete endothelin-1. Endothelin-1 binding was mediated exclusively by the endothelin B-receptor. In 3-dimensional collagen gels, spontaneous contraction of myofibroblasts from estrogen-treated women with prolapse was statistically significantly lower than from young primiparous women. Exogenous addition of endothelin-1 decreased the spontaneous contraction of myofibroblasts.

CONCLUSION

Genital myofibroblasts of women with uterovaginal prolapse are poorly contractile, and endothelin-1 further decreases vaginal myofibroblast contraction, which is opposite to observations in skin myofibroblasts.