Pelvic floor disorders: linking genetic risk factors to biochemical changes

Silencing of cysteine and serine rich nuclear protein 1 inhibits apoptosis, senescence and collagen degradation in human-derived vaginal fibroblasts in response to oxidative stress or DNA damage

Pelvic organ prolapse (POP) is a group of diseases caused by extracellular matrix (ECM) degradation in pelvic supportive tissues. Cysteine and serine rich nuclear protein 1 (CSRNP1) is involved in cell proliferation and survival regulation, and reportedly facilitates collagen breakdown in human chondrocytes. The present study aimed to probe the effect of CSRNP1 on collagen metabolism in human-derived vaginal fibroblasts. High expression of CSRNP1 was found in POP patient-derived vaginal fibroblasts in comparison to normal-derived vaginal fibroblasts. Following functional experiments revealed that CSRNP1 overexpression led to proliferation inhibition, apoptosis and collagen degradation in normal vaginal fibroblasts. In line with this, silencing of CSRNP1 inhibited hydrogen peroxide (H2O2)-triggered apoptosis, ROS generation and collagen loss in normal vaginal fibroblasts. Silencing of CSRNP1 also reduced the expression of cell senescence markers p21 and γ-H2Ax (the histone H2Ax phosphorylated at Ser139), as well as curbed collagen breakdown in normal vaginal fibroblasts caused by a DNA damage agent etoposide. Transcriptomic analysis of vaginal fibroblasts showed that differentially expressed genes affected by CSRNP1 overexpression were mainly enriched in the Wnt signaling pathway. Treatment with a Wnt pathway inhibitor DKK1 blocked CSRNP1 knockdown-caused collagen deposition. Mechanistically, CSRNP1 was identified to be a target of Snail family transcriptional repressor 2 (SNAI2). Forced expression of CSRNP1 reversed the anti-apoptotic, anti-senescent and anti-collagen loss effects of SNAI2 in normal vaginal fibroblasts exposed to H2O2 or etoposide. Our study indicates that the SNAI2/CSRNP1 axis may be a key driver in POP progression, which provides a potential therapeutic strategy for POP.

The 50 most cited articles and science mapping analysis of vaginal tightening

INTRODUCTION AND HYPOTHESIS

The study was aimed at exploring the 50 most cited articles related to vaginal tightening.

METHODS

The papers were searched through the Thomson Reuters Web of Science on 30 July 2022, and were ranked by the total number of citations. The included articles were analyzed for author, journal, country, number of citations, keywords, subject matter, and level of evidence. The search output was also imported into VOSviewer.

RESULTS

The 50 most cited articles were cited a combined total of 2,558 times. The papers were published between 1990 and 2020, of which 86% were published between 2010 and 2020. They included 38 original articles, 8 reviews, 3 editorial articles, and 1 letter. Most articles were published in gynecology-related journals (n=30, 60%). The articles covered a wide range of topics, the most common being laser/radiofrequency treatment, vaginal tightening procedures, and urinary incontinence. The majority presented findings supported by level IV or V evidence. Through co-occurrence analysis, high-frequency words and countries were displayed well.

CONCLUSIONS

The study shed light on frequently read articles and influential topics about vaginal tightening. The highly cited literature mainly focused on laser or radiofrequency treatments and gynecologists currently dominate the highly cited literature on vaginal tightening. The articles related to surgical treatments are low in number and evidence level so far. The co-occurrence analysis reveals the hot research content and active countries in the field. In general, the study provides useful evidence for future research and educational materials.

Exosomes derived from mesenchymal stromal cells: a promising treatment for pelvic floor dysfunction

Pelvic floor dysfunction (PFDs), which include pelvic organ prolapse (POP), stress urinary incontinence (SUI) and anal incontinence (AI), are common degenerative diseases in women that have dramatic effects on quality of life. The pathology of PFDs is based on impaired pelvic connective tissue supportive strength due to an imbalance in extracellular matrix (ECM) metabolism, the loss of a variety of cell types, such as fibroblasts, muscle cells, peripheral nerve cells, and oxidative stress and inflammation in the pelvic environment. Fortunately, exosomes, which are one of the major secretions of mesenchymal stromal cells (MSCs), are involved in intercellular communication and the modulation of molecular activities in recipient cells via their contents, which are bioactive proteins and genetic factors such as mRNAs and miRNAs. These components modify fibroblast activation and secretion, facilitate ECM modelling, and promote cell proliferation to enhance pelvic tissue regeneration. In this review, we focus on the molecular mechanisms and future directions of exosomes derived from MSCs that are of great value in the treatment of PFD.

Platelet-rich Plasma Promotes Restoration of the Anterior Vaginal Wall for the Treatment of Pelvic Floor Dysfunction in Rats

STUDY OBJECTIVE

To determine the efficacy of using platelet-rich plasma (PRP) for vaginal wall repair in rats with vaginal wall impairment induced by vaginal distension (VD).

DESIGN

A single-blind, randomized study.

SETTING

A certified animal research facility.

ANIMALS

Twenty-four female Sprague Dawley rats.

INTERVENTIONS

Female Sprague Dawley rats were divided into sham (n = 8), VD (n = 8), and VD + PRP (n = 8) groups. Vaginal tissues from the VD group were dissected at 28-day post injury. VD + PRP rats received vaginal PRP injections on the 1st, 7th, 14th, and 21st day after VD and sacrificed on the 28th day.

MEASUREMENTS AND MAIN RESULTS

Urodynamic tests were performed in all rats. Immunohistochemistry was used to evaluate matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9). Masson's staining was used to evaluate collagen fibers and calculate collagen volume fraction. Collagen fiber damage was confirmed in the VD group, evidenced by thinner and sparse distribution of collagen fibers, with significantly higher MMP-2 and MMP-9 expression than the sham group (p <.05). The collagen fiber damage in the vaginal wall likely led to pelvic floor dysfunction (PFD), evidenced by significantly decreased bladder leak-point pressure (p <.01) and abdominal leak-point pressure (p <.01) in the VD group compared with the sham group. After completion of the PRP treatment, a significantly higher collagen volume fraction (p <.01) and significantly increased bladder leak-point pressure (p <.05) and abdominal leak-point pressure (p <.01) were achieved in the VD + PRP compared with the VD group, thus indicating repair of the vaginal wall and improvement of PFD.

CONCLUSION

PRP injections facilitate the regeneration of vaginal wall tissue, particularly collagen fiber, after VD, leading to functional improvement of PFD. Findings support the feasibility of using PRP as a novel treatment for PFD.

New aspects in the surgical correction of pelvic organ prolapse

Relevance . The relevance of the problem of pelvic prolapse is due to the prevalence of the disease, the tendency to rejuvenation and progression. This, according to the survey, affects the quality of life of women, leads to disruption of sexual functioning, and reduces the ability to work. The methods of surgical treatment that exist in the arsenal of modern operative gynecology can contribute to the development of cicatricial adhesions, infectious complications and recurrence of prolapse, which creates the need for repeated interventions. The development and introduction into practice of new methods of treatment is a natural necessity. The most effective technique for the surgical treatment of genital prolapse is laparoscopic sacrocolpopexy using titanium silk implants. Materials and Methods. A prospective cohort study of 30 patients aged 37 to 74 years with clinical manifestations of grade II-IV prolapse, statistical data analysis and analysis of the results of a survey of patients in the postoperative period in dynamics over 3-6-12 months from 2019 to 2021 was carried out. The study used a three-stage method of surgical assistance (patent dated September 15, 2020 No. 2020130382/14 (054923) in the volume - laparoscopic promontofixation, MacCoul sacro-uterine ligament plasty, colporrhaphy, colpoperineorrhaphy, levatoroplasty. Results and Discussion. It has been established that pregnancy and childbirth are among the main factors provoking the development of pelvic floor muscle failure. The duration of postoperative follow-up in our study was 3-14 months. No complications were diagnosed during this period. In 12 patients (40.0 %) during the first month there were periodic pulling pains in the lower abdomen and perineum, in 2 (6.6 %) - urinary incontinence. Titanium silk has a lower affinity for surrounding tissues compared to polypropylene scaffold systems, which makes it possible to consider it as an alternative material to synthetic analogues and reduce the risk of mesh-associated complications. The resistance of the titanium endoprosthesis to antiseptics and microbial agents predisposes to its long-term use and the absence of the need for replacement. Conclusion. The data obtained make it possible to judge the high efficiency of the developed technique for the surgical treatment of pelvic prolapse of pelvic floor defects in patients with rectocele and cystocele, minimizing the recurrence of the disease and the risk of developing mesh-associated complications, which allows choosing a personalized management strategy for this cohort of patients.

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.

Associations between metabolic syndrome and female stress urinary incontinence: a meta-analysis

INTRODUCTION AND HYPOTHESIS

The objective was to identify the associations between metabolic syndrome (MS) and stress urinary incontinence (SUI) in women and to provide an evidence base for clinical practice.

METHODS

A meta-analysis of cohort, case-control, and cross-sectional studies about the association between MS and SUI was performed using databases including PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBMdisc), Wanfang Database (WanFang Data), and VIP database (VIP). The time limit was from the commencement of each database to 1 November 2020. Two researchers independently screened literature, extracted data, and assessed the risk of bias. RevMan 5.3 software was used for statistical analysis. The dichotomous variables were presented as the risk ratio (odds ratio, OR) and 95% CI as the effect indicators.

RESULTS

Six studies were included in the meta-analysis, with a total sample size of 3,678 cases. The results showed that the risk for SUI in women with MS was three times those without MS (OR = 3.41, 95% CI 2.01, 5.77, p <0.00001), and the difference was statistically significant. The results of subgroup analysis showed that MS was significantly associated with SUI in the subgroups of pre- and postmenopausal women (OR = 2.46, 95% CI 1.63, 3.73, p < 0.00001), and in the subgroups of other types of women (OR = 3.41, 95% CI 2.01, 5.77, p = 0.0003), and the differences were statistically significant.

CONCLUSIONS

Metabolic syndrome is associated with SUI in women and increases its risk.

Role of Fibroblasts and Myofibroblasts on the Pathogenesis and Treatment of Pelvic Organ Prolapse

Pelvic organ prolapse (POP) is a multifactorial connective tissue disorder caused by damage to the supportive structures of the pelvic floor, leading to the descent of pelvic organs in the vagina. In women with POP, fibroblast function is disturbed or altered, which causes impaired collagen metabolism that affects the mechanical properties of the tissue. Ideal surgical repair, either native tissue repair or POP surgery using an implant, aims to create a functional pelvic floor that is load-bearing, activating fibroblasts to regulate collagen metabolism without creating fibrotic tissue. Fibroblast function plays a crucial role in the pathophysiology of POP by directly affecting the connective tissue quality. On the other hand, fibroblasts determine the success of the POP treatment, as the fibroblast-to-(myo)fibroblast transition is the key event during wound healing and tissue repair. In this review, we aim to resolve the question of “cause and result” for the fibroblasts in the development and treatment of POP. This review may contribute to preventing the development and progress of anatomical abnormalities involved in POP and to optimizing surgical outcomes.

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.

Proteins in plasma as a potential biomarkers diagnostic for pelvic organ prolapse

Background

Pelvic organ prolapse (POP) is the most common and widespread type of female pelvic floor dysfunction disease (PFD). At present, the diagnosis of POP is mainly based on a complicated systematic evaluation of the clinical phenotype, medical history, and relevant functional examinations. Rapid and simple tests that are based on biochemical biomarkers that surpass the sensitivity and specificity of the current methods for the diagnosis of POP will greatly facilitate the timely diagnosis and treatment of women with POP.

Methods

A protein array was used to screen plasma samples collected from healthy controls and women with POP. Enzyme-linked immunosorbent assays (ELISAs) were used to determine the levels of three novel and potentially useful analytes: heat shock protein 10 (HSP10), zinc finger CCCH domain-containing protein 8 (ZC3H8), and unc-45 myosin chaperone A (UNC45A). We then determined the diagnostic value of each of these analytes as potential diagnostic biomarkers for clinical application.

Results

The mean levels of HSP10, ZC3H8, and UNC45A, were lower in the plasma samples from 76 patients with POP than in 56 samples from healthy controls (P<0.05). Comparisons between patients with POP and healthy controls demonstrated the sensitivity and specificity of HSP10 (73.7% and 71.4%), ZC3H8 (71.1% and 62.5%), and UNC45A (70.7% and 62.5%).

Conclusions

Analysis indicated that plasma levels of HSP10, ZC3H8, and UNC45A, are sensitive and specific biomarkers for the diagnosis of POP.

The extracellular matrix molecules versican and hyaluronan in urethral and vaginal tissues in stress urinary incontinence

PURPOSE

Abnormal extracellular matrix (ECM) changes are correlated with stress urinary incontinence (SUI). The ECM components versican (Vcan) and hyaluronan (HA) play key roles in regulating tissue inflammation and maintaining connective tissue homeostasis. We analyzed the localization and expression of these ECM components in urethral and vaginal tissues from a rat model of urinary incontinence and from human clinical specimens.

METHODS

Nulliparous rats underwent vaginal distension (VD), a rodent model of SUI, or a sham procedure. Tissues were harvested from six rats per group at days 1, 4, and 21 for immunohistochemistry and RNA expression analysis of ECM components. Periurethral vaginal samples from female patients with SUI were also examined.

RESULTS

High-intensity staining for Vcan was observed 1 day after procedure in both control and VD animals. This level of abundance persisted at day 4 in VD compared to control, with concurrent reduced messenger RNA (mRNA) expression of the Vcan-degrading enzymes ADAMTS5 and ADAMTS9 and reduced staining for the Vcan cleavage epitope DPEAAE. Abundance of HA was not different between VD and control, however mRNA expression of the HA synthase Has2 was significantly reduced in VD tissues at day 4. Abundant Vcan staining was observed in 60% of SUI patient samples, which was strongest in regions of disrupted elastin.

CONCLUSION

Reduction of Vcan-degrading enzymes and HA synthases at day 4 postsurgery indicates a potential delay in ECM turnover associated with SUI. Abundant Vcan is associated with inflammation and elastin fiber network disruption, warranting further investigation to determine its role in SUI pathogenesis.

Prevalence and Predictors of Urinary Incontinence at 1 Year Postpartum

OBJECTIVES

Postpartum urinary incontinence estimates range from 13% to 47%. Clinical factors associated with incontinence 1 year after first delivery are varied. We assessed the prevalence of and factors associated with urinary incontinence in primiparous women at 12 months postpartum.

METHODS

Ancillary analysis of 99 nulliparous women from a prospective cohort study that assessed participants during the first and third trimesters and 12 months postpartum. Our primary outcome was urinary incontinence 12 months postpartum. Women were asked "How often do you experience urine leakage?" and considered to have urinary incontinence if a response other than "never" was reported. We collected vaginal swabs for assessment of matrix metalloproteinase-9 activity, a measure of tissue remodeling. Bivariable and logistic regression analyses were used to compare women with and without postpartum urinary incontinence.

RESULTS

Of 99 primiparous women, 55% (n = 54) reported urinary incontinence at 12 months postpartum. Logistic regression demonstrated that urinary incontinence during pregnancy (odds ratio, 34.3; 95% confidence interval, 7.9-149.2) and a decrease in matrix metalloproteinase 9 activity between the first and third trimesters (odds ratio, 19.34; 95% confidence interval, 3.47-107.84) were associated with postpartum urinary incontinence. The sensitivity and specificity of urinary incontinence during pregnancy for predicting postpartum urinary incontinence were 87% and 67%, respectively. The positive and negative predictive values were 76% and 81%, respectively.

CONCLUSIONS

Urinary incontinence affected 55% of primiparous women at 12 months postpartum. Urinary incontinence during pregnancy was strongly associated with postpartum incontinence. Importantly, vaginal tissue protease activity during pregnancy represents a possible mechanism for and biomarker of postpartum urinary incontinence.

Oxidative Stress: A Possible Trigger for Pelvic Organ Prolapse

Pelvic organ prolapse is a frequent health problem in women, encountered worldwide, its physiopathology being still incompletely understood. The integrity of the pelvic-supportive structures is a key element that prevents the prolapse of the pelvic organs. Numerous researchers have underlined the role of connective tissue molecular changes in the pathogenesis of pelvic organ prolapse and have raised the attention upon oxidative stress as an important element involved in its appearance. The advancements made over the years in terms of molecular biology have allowed researchers to investigate how the constituent elements of the pelvic-supportive structures react in conditions of oxidative stress. The purpose of this paper is to underline the importance of oxidative stress in the pathogenesis of pelvic organ prolapse, as well as to highlight the main oxidative stress molecular changes that appear at the level of the pelvic-supportive structures. Sustained mechanical stress is proven to be a key factor in the appearance of pelvic organ prolapse, correlating with increased levels of free radicals production and mitochondrial-induced fibroblasts apoptosis, the rate of cellular apoptosis depending on the intensity of the mechanical stress, and the period of time the mechanical stress is applied. Oxidative stress hinders normal cellular signaling pathways, as well as different important cellular components like proteins, lipids, and cellular DNA, therefore significantly interfering with the process of collagen and elastin synthesis.

BMMSC-sEV-derived miR-328a-3p promotes ECM remodeling of damaged urethral sphincters via the Sirt7/TGFβ signaling pathway

Background

Stress urinary incontinence (SUI) is a common and bothersome condition. Invasive surgery will always be considered after conservative treatment fails, but the rates of postoperative complications and long-term recurrence are high. Thus, a new treatment strategy is still needed. In recent years, bone marrow mesenchymal stem cells (BMMSC) have shown great promise for SUI treatment. The therapeutic effects of BMMSC on SUI are achieved mainly by paracrine pathway signaling molecules, such as small extracellular vesicles (sEV). sEV are recognized as essential mediators of cell-to-cell communication. However, the therapeutic effects and detailed mechanisms of BMMSC-derived sEV in SUI remain mostly unexplored.

Methods

The effects of BMMSC-sEV on extracellular matrix (ECM) metabolism were assessed in vitro and in vivo. In a SUI rat model, TGF-β1 signaling was examined with or without BMMSC-sEV stimulation. sEV miRNAs were deeply sequenced, and the most likely miRNAs were evaluated as mediators of the TGF-β1 signaling pathway.

Results

BMMSC-sEV enhanced the synthesis of ECM components, including elastin, collagen I, and collagen III, and improved urethral function. Furthermore, BMMSC-sEV activated TGF-β1 signaling in primary fibroblast cells and in rat urethras. Several differentially expressed miRNAs were identified in the BMMSC-sEV. Bioinformatics analysis and in vitro studies showed that BMMSC-sEV miR-328a-3p can be transferred from BMMSC to fibroblasts and can regulate the Sirt7/TGF-β1 signaling pathway.

Conclusion

BMMSC-sEV promote ECM remodeling of damaged urethral sphincters by transferring miR-328a-3p to regulate the Sirt7/TGF-β1 signaling pathway.

Status, challenges, and future prospects of stem cell therapy in pelvic floor disorders

Pelvic floor disorders (PFDs) represent a group of common and frequently-occurring diseases that seriously affect the life quality of women, generally including stress urinary incontinence and pelvic organ prolapse. Surgery has been used as a treatment for PFD, but almost 30% of patients require subsequent surgery due to a high incidence of postoperative complications and high recurrence rates. Therefore, investigations of new therapeutic strategies are urgently needed. Stem cells possess strong multi-differentiation, self-renewal, immunomodulation, and angiogenesis abilities and they are able to differentiate into various cell types of pelvic floor tissues and thus provide a potential therapeutic approach for PFD. Recently, various studies using different autologous stem cells have achieved promising results by improving the pelvic ligament and muscle regeneration and conferring the tissue elasticity and strength to the damaged tissue in PFD, as well as reduced inflammatory reactions, collagen deposition, and foreign body reaction. However, with relatively high rates of complications such as bladder stone formation and wound infections, further studies are necessary to investigate the role of stem cells as maintainers of tissue homeostasis and modulators in early interventions including therapies using new stem cell sources, exosomes, and tissue-engineering combined with stem cell-based implants, among others. This review describes the types of stem cells and the possible interaction mechanisms in PFD treatment, with the hope of providing more promising stem cell treatment strategies for PFD in the future.

Pelvic floor disorder symptoms and bone strength in postmenopausal women

INTRODUCTION AND HYPOTHESIS

The current study is aimed at characterizing the association between pelvic floor disorder symptoms and bone strength reflecting a potential connective tissue pathophysiology in postmenopausal women.

METHODS

A cross-sectional study was conducted in postmenopausal women undergoing osteoporosis evaluation from 2007 to 2010. Urinary incontinence (UI) was defined as urinary leakage ≥2-3 times/week. UI types were defined using the 3 Incontinence Questionnaire. Fecal incontinence was defined as stool leakage ≥1/month, and pelvic organ prolapse as a positive response to "Do you have a bulge or something falling out that you can see or feel in your vaginal area?" Bone quality and quantity were assessed using the trabecular bone score (TBS) and bone mineral density respectively: bone strength was defined by combined quality/quantity index, low strength being equivalent to moderate to severe fracture risk; low quality as TBS ≤ 1.31; low quantity by T-score <-1 or on osteoporosis medication.

RESULTS

Of 681 subjects, 262 had low bone strength whereas 419 were normal using the combined quality/quantity bone assessment. Characteristics were similar except for age (low bone strength: 69.0 ± 8.2 vs normal: 65.0 ± 7.1, p < 0.01) and smoking (8.8% vs 3.3%, p < 0.01). Low bone strength was associated with any UI (adjusted odds ratio [aOR]: 1.48, 1.05-2.10), stress (aOR: 1.53, 1.06-2.21), and mixed (aOR :1.45, 1.02-2.05). Women with low bone quality had increased odds of UI (any, urgency, mixed), whereas none of the pelvic floor disorder symptoms was associated with low bone quantity.

CONCLUSIONS

Low bone strength defined by a combined quantity/quality index, as well as low bone quality alone, were associated with increased risk of UI.

Metabolomics study of serum and urine samples reveals metabolic pathways and biomarkers associated with pelvic organ prolapse

Pelvic organ prolapse (POP) is a common medical condition among women and involves complicated diagnostics and controversial surgical management. The exact molecular mechanism underlying POP is poorly understood, especially at the metabolism level. To explore the metabolic mechanism underlying POP and discover potential biomarkers for POP diagnosis, we applied a non-targeted metabolomics approach using ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). Metabolomics study of serum samples from patients with POP (n = 24) and controls (n = 22) revealed a total of 59 metabolites that are significantly different (VIP ≥ 1 and p ≤ 0.05) between the two groups. Between urine samples from POP patients (n = 45) and controls (n = 59), 33 metabolites differed significantly (VIP ≥ 1 and p ≤ 0.05). Metabolic pathways affected by these differentially expressed metabolites were analyzed. In both serum and urine samples, three pathways including arginine biosynthesis and purine metabolism were found to be significantly related to POP. Six metabolites including GPC, 1-methyladenosine, maleic acid, L-pyroglutamic acid, inosine, and citrate are significantly changed (VIP ≥ 1 and p ≤ 0.05) in both serum and urine samples from patients with POP. Receiver operating characteristics (ROC) curve analysis showed that using these six metabolites as a biomarker could distinguish patients with POP from controls with good accuracy in both serum (AUC = 1) and urine samples (AUC = 0.854). Collectively, these results further extended our understanding of key regulatory metabolic pathways involved in the pathophysiology of POP, as well as provided some promising biomarkers for effective POP diagnosis.

Gene expression in stress urinary incontinence: a systematic review

INTRODUCTION

A contribution of genetic factors to the development of stress urinary incontinence (SUI) is broadly acknowledged. This study aimed to: (1) provide insight into the genetic pathogenesis of SUI by gathering and synthesizing the available data from studies evaluating differential gene expression in SUI patients and (2) identify possible novel therapeutic targets and leads.

METHODS

A systematic literature search was conducted through September 2017 for the concepts of genetics and SUI. Gene networking connections and gene-set functional analyses of the identified genes as differentially expressed in SUI were performed using GeneMANIA software.

RESULTS

Of 3019 studies, 4 were included in the final analysis. A total of 13 genes were identified as being differentially expressed in SUI patients. Eleven genes were overexpressed: skin-derived antileukoproteinase (SKALP/elafin), collagen type XVII alpha 1 chain (COL17A1), plakophilin 1 (PKP1), keratin 16 (KRT16), decorin (DCN), biglycan (BGN), protein bicaudal D homolog 2 (BICD2), growth factor receptor-bound protein 2 (GRB2), signal transducer and activator of transcription 3 (STAT3), apolipoprotein E (APOE), and Golgi SNAP receptor complex member 1 (GOSR1), while two genes were underexpressed: fibromodulin (FMOD) and glucocerebrosidase (GBA). GeneMANIA revealed that these genes are involved in intermediate filament cytoskeleton and extracellular matrix organization.

CONCLUSION

Many genes are involved in the pathogenesis of SUI. Furthermore, whole-genome studies are warranted to identify these genetic connections. This study lays the groundwork for future research and the development of novel therapies and SUI biomarkers in clinical practice.

Recent advances in pelvic floor repair

Stress urinary incontinence (SUI) and pelvic organ prolapse (POP) are conditions which result in significant physical, mental and social consequences for women worldwide. The high rates of recurrence reported with primary repair for POP led to the use of synthetic mesh to augment repairs in both primary and secondary cases following failed previous POP repair. The widely reported, unacceptably high rates of complications associated with the use of synthetic, transvaginal mesh in pelvic floor repair have severely limited the treatment options that surgeons can offer. This article summarises the recent advances in pelvic floor repair, such as improved quantification and modelling of the biomechanics of the pelvic floor and the developing technology within the field of tissue engineering for treatment of SUI/POP, including biomaterials and cell-based therapies. Finally, we will discuss the issues surrounding the commercial introduction of synthetic mesh for use within the pelvic floor and what lessons can be learned for the future as well as the current guidance surrounding treatment for SUI/POP.

Molecular aspects of collagenolysis associated with stress urinary incontinence in women with urethral hypermobility vs intrinsic sphincter deficiency

AIMS

We aimed to assess the alterations in specific molecular mechanisms associated with collagenolysis and their correlation in cases of stress urinary incontinence (SUI) by urethral hypermobility (UH) and by intrinsic sphincter deficiency (ISD).

METHODS

We evaluated the messenger RNA (mRNA) expression of matrix metalloproteinases (MMP1, MMP2, and MMP9), specific tissue inhibitors of metalloproteinases (TIMPs), and associated proteins (TIMP1, TIMP2, and α-2-macroglobulin [A2McG]) in the suburethral tissue of women with SUI (half with SUI by UH and half with SUI by ISD) by reverse-transcriptase quantitative polymerase chain reaction and determined the correlations of the expression of these proteins on each pathological condition.

RESULTS

In the suburethral tissue, we found significantly altered MMP2 mRNA levels, being higher in women with ISD than in those with UH. Still, MMP1 and MMP9 exhibited a tendency to a higher expression in women with ISD. Concerning the TIMPs expression, no significant statistical differences were found between women with UH and ISD. When evaluating the MMP/TIMP ratios, we found significant statistical differences between MMP9/TIMP1 and MMP9/A2McG. In fact, the correlations of the expression MMP9 with TIMP1 and A2McG were lost for women with UH. The ratios between MMP1/TIMP1 and MMP1/A2McG were similar, although there was a tendency of higher ratio in ISD for MMP2/TIMP2 and MMP2/A2McG.

CONCLUSION

Our results point toward higher collagenolysis in the suburethral tissue of women with SUI by ISD.

Study of the polymorphism rs3025058 of the MMP-3 gene and risk of pelvic organ prolapse in Brazilian women

Objective

To analyze the polymorphism -1171 5A / 6A rs3025058 of the MMP-3 gene and the risk for pelvic organ prolapse (POP).

Study Design

This is a cohort study. All patients attended the Urogynecology and Vaginal Surgery Section of the FMABC, from 2014 to 2016 and they were randomly recruited by the researchers at the first medical appointment. We selected 112 patients with symptomatic POPs and 180 patients with normal pelvic floors. The single nucleotide polymorphism (SNP) 5A / 6A of MMP-3 was determined by polymerase chain reaction (PCR) and analysis of the restriction fragments in both groups. Chi-squared test was used to compare the frequencies of polymorphisms between the groups. For those characteristics with statistical relevance, the crude odds ratio (OR) and its respective 95% confidence intervals were calculated; and, by logistic regression, were adjusted for each of the other characteristics, obtaining the adjusted OR. Hardy-Weinberg gene balance was determined using Pearson's Chi-squared test. Values of p < 0.05 were considered statistically significant.

Results

Logistic regression of factors associated with genital prolapse showed that age (adjusted OR = 11.89, 95% CI, 3.53-40) and home delivery (adjusted OR = 9.645, 95% CI, 3.35-27.7) remained risk factors for genital prolapse in the sample studied. There was no statistically significant difference between the groups in the distribution of genotypes, even after calculating the contribution of the 5A recessive allele in the aggregated genotypes (5A / 5A + 5A / 6A).

Conclusion

The polymorphism -1171 5A / 6A rs3025058 of the MMP-3 gene was not associated with the risk for POP. Age and home delivery were significantly associated with increased risk for the disease.

The influence of hyperglycemia on the remodeling of urethral connective tissue in pregnant rats

OBJECTIVE

To analyze the distribution and quantification of the key structural extracellular matrix components of the urethral tissue in a rat model of hyperglycemia and pregnancy.

STUDY DESIGN

A total of 120 female Wistar rats were distributed into the following four experimental groups: virgin, pregnant, hyperglycemic and hyperglycemic + pregnant groups. The urethra was harvested for histochemical, morphometric, immunohistochemical, Western blot and glycosaminoglycan analyses. All protocols were approved by the Institutional Animal Care and Use Committee of Botucatu Medical School (process number 828-2010).

RESULTS

The hyperglycemic + pregnant group showed significantly increased stiffness in urethral tissue. The total striated muscle was decreased, with increased deposition of collagen fibers around the muscle fibers and a change in the organization of the collagen fibrils. An increase in the relative collagen type I/III ratio and a decrease in total glycosaminoglycans were also observed.

CONCLUSIONS

This study provides the first line of experimental evidence supporting a metabolic relationship between hyperglycemia and urethral remodeling of connective tissue in pregnant rats. The different organization of the collagen fibrils and the profile of glycosaminoglycans found in urethral samples suggest that the pathology of the urethral fibromuscular system could be related to hyperglycemia-induced pelvic floor dysfunction in women, which has direct clinical implications with the possibility to develop new multidisciplinary treatments for improving the health care of these women.

Effects of multiple simulated birth traumas on urethral continence function in rats

Multiple vaginal parities have been reported to be an important risk factor for stress urinary incontinence (SUI). Simulated birth trauma with single vaginal distention (VD) has been used to induce the SUI condition in animals; however, the effect of multiple simulated birth traumas on the urethral continence function has not been well characterized. Therefore, we examined the effects of multiple VDs on urethral functions in vivo and the changes in gene expressions of several molecules in the urethra using female SD rats, which were divided into three groups; sham, VD-1 (single VD), and VD-3 groups (3 times of VDs every 2 wk). Two weeks after the final VD, leak point pressure (LPP) and urethral responses during sneezing were evaluated. Also, changes in mRNA levels of urethral molecules were quantified with RT-PCR.　The VD-1 group did not show any change in LPP with only a tendency of decrease in amplitudes of the urethral responses during sneezing (A-URS); however, the VD-3 group showed a significant decrease in LPP and urethral responses such as baseline urethral pressure and A-URS accompanied with SUI episodes during sneezing. Nicotinic receptor subtypes and transforming growth factor (TGF)-β1 were significantly increased in both VD-1 and VD-3 groups while TNF receptor (TNFR)-1, IL-6, collagens, and matrix metalloproteinases-9 were significantly increased only in the VD-3 group.　These data indicate that rats with multiple simulated birth traumas exhibit profound impairment of the urethral continence function and that these functional changes are associated with those in cytokines, extracellular matrix molecules, and nicotinic receptor subtypes in the urethra.

Expression changes in pelvic organ prolapse: a systematic review and in silico study

Pelvic organ prolapse (POP) is a highly disabling condition common for a vast number of women worldwide. To contribute to existing knowledge in POP pathogenesis, we performed a systematic review of expression studies on both specific gene and whole-genome/proteome levels and an in silico analysis of publicly available datasets related to POP development. The most extensively investigated genes in individual studies were related to extracellular matrix (ECM) organization. Three premenopausal and two postmenopausal sets from two Gene Expression Omnibus (GEO) studies (GSE53868 and GSE12852) were analyzed; Gene Ontology (GO) terms related to tissue repair (locomotion, biological adhesion, immune processes and other) were enriched in all five datasets. Co-expression was higher in cases than in controls in three premenopausal sets. The shared between two or more datasets up-regulated genes were enriched with those related to inflammatory bowel disease (IBD) in the NHGRI GWAS Catalog. ECM-related genes were not over-represented among differently expressed genes. Up-regulation of genes related to tissue renewal probably reflects compensatory mechanisms aimed at repair of damaged tissue. Inefficiency of this process may have different origins including age-related deregulation of gene expression.

Efficacy and Safety of Immuno-Magnetically Sorted Smooth Muscle Progenitor Cells Derived from Human-Induced Pluripotent Stem Cells for Restoring Urethral Sphincter Function

Human-induced pluripotent stem cells (hiPSCs)-based cell therapy holds promise for treating stress urinary incontinence (SUI). However, safety concerns, especially tumorgenic potential of residual undifferentiated cells in hiPSC derivatives, are major barriers for its clinical translation. An efficient, fast and clinical-scale strategy for purifying committed cells is also required. Our previous studies demonstrated the regenerative effects of hiPSC-derived smooth muscle progenitor cells (pSMCs) on the injured urethral sphincter in SUI, but the differentiation protocol required fluorescence-activated cell sorting (FACS) which is not practical for autologous clinical applications. In this study, we examined the efficacy and safety of hiPSC-derived pSMC populations sorted by FDA-approved magnetic-activated cell sorting (MACS) using cell-surface marker CD34 for restoring urethral sphincter function. Although the heterogeneity of MACS-sorted pSMCs was higher than that of FACS-sorted pSMCs, the percentage of undifferentiated cells dramatically decreased after directed differentiation in vitro. In vivo studies demonstrated long-term cell integration and no tumor formation of MACS-sorted pSMCs after transplantation. Furthermore, transplantation of MACS-sorted pSMCs into immunodeficient SUI rats was comparable to transplantation with FACS-sorted pSMCs for restoration of the extracellular matrix metabolism and function of the urethral sphincter. In summary, purification of hiPSC derivatives using MACS sorting for CD34 expression represent an efficient approach for production of clinical-scale pSMCs for autologous stem cell therapy for regeneration of smooth muscle tissues. Stem Cells Translational Medicine 2017;6:1158-1167.

Proteomic Analysis of the Uterosacral Ligament in Postmenopausal Women with and without Pelvic Organ Prolapse

BACKGROUND

Pelvic organ prolapse (POP) is a major health problem in adult women that involves many factors. No proteomic analysis has been conducted exclusively in POP patients. This study aimed to identify the differential expression of proteins that may be involved in POP by proteomic analysis.

METHODS

Samples of the uterosacral ligament (USL) were collected from five POP patients and five non-POP patients matched according to age, parity, and menopausal status and analyzed using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the mRNA expression of proteins that showed differential expression in the proteomic analyses.

RESULTS

Proteins differentially expressed between POP and non-POP patients were detected. Eight proteins that were down-regulated in the POP group were identified by MALDI-TOF-MS. These proteins included electron transfer flavoprotein, apolipoprotein A-I, actin, transgelin, cofilin-1, cyclophilin A, myosin, and galectin-1, and their expression was verified by qRT-PCR.

CONCLUSION

Using comparative proteomics, we identified eight differentially expressed proteins (including four cytoskeleton proteins and three proteins related to apoptosis) in the USL that may be involved in apoptosis associated with the tissue effects in POP pathophysiology.

Smooth Muscle Progenitor Cells Derived From Human Pluripotent Stem Cells Induce Histologic Changes in Injured Urethral Sphincter

: Data suggest that myoblasts from various sources, including bone marrow, skeletal muscle, and adipose tissue, can restore muscle function in patients with urinary incontinence. Animal data have indicated that these progenitor cells exert mostly a paracrine effect on the native tissues rather than cell regeneration. Limited knowledge is available on the in vivo effect of human stem cells or muscle progenitors on injured muscles. We examined in vivo integration of smooth muscle progenitor cells (pSMCs) derived from human pluripotent stem cells (hPSCs). pSMCs were derived from a human embryonic stem cell line (H9-ESCs) and two induced pluripotent stem cell (iPSC) lines. pSMCs were injected periurethrally into urethral injury rat models (2 × 10⁶ cells per rat) or intramuscularly into severe combined immunodeficiency mice. Histologic and quantitative image analysis revealed that the urethras in pSMC-treated rats contained abundant elastic fibers and thicker muscle layers compared with the control rats. Western blot confirmed increased elastin/collagen III content in the urethra and bladder of the H9-pSMC-treated rats compared with controls. iPSC-pSMC treatment also showed similar trends in elastin and collagen III. Human elastin gene expression was not detectable in rodent tissues, suggesting that the extracellular matrix synthesis resulted from the native rodent tissues rather than from the implanted human cells. Immunofluorescence staining and in vivo bioluminescence imaging confirmed long-term engraftment of pSMCs into the host urethra and the persistence of the smooth muscle phenotype. Taken together, the data suggest that hPSC-derived pSMCs facilitate restoration of urethral sphincter function by direct smooth muscle cell regeneration and by inducing native tissue elastin/collagen III remodeling.

SIGNIFICANCE

The present study provides evidence that a pure population of human smooth muscle progenitor cells (pSMCs) derived from human pluripotent stem cells (hPSCs) (human embryonic stem cells and patient induced pluripotent stem cells) restores urethral sphincter function by two mechanisms: modulation of extracellular matrix protein metabolism in vivo and pSMC proliferation and differentiation into smooth muscle cells to regenerate the muscle layer in the lower urinary tract. These findings on the in vivo effects of human pSMCs should aid in optimizing regenerative therapies using human myoblasts.

Transvaginal rectocele repair with human dermal allograft interposition and bilateral sacrospinous fixation with a minimum eight-year follow-up

BACKGROUND

Human dermal allografts have been used for over a decade for interpositional repair of rectoceles. How do dermal allografts perform with regards to success rate and complications with 8 years' minimum follow-up?

METHODS

We retrospectively reviewed 41 consecutive patients undergoing dermal allograft interposition procedures between October 2001 and December 2005 (Repliform, Boston Scientific, Natick, MA, USA) for stage two, three, and four International Continence Society (ICS) symptomatic rectocele repairs with bilateral sacrospinous fixation. Failure was defined as recurrent stage two International Continence Society prolapse (Ap ≥ -1 and/or Bp ≥ -1). All questionnaires were completed 1 week before surgery and at follow-up (September 2014 through December 2014).

RESULTS

The mean preoperative and postoperative A(p) were 0.95 ± 0.70,-1.90 ± 0.52 and B(p) 1.30 ± 0.84,-2.13 ± 0.51 (p < 0.001). With a mean follow-up of 116.5 ± 18.9 months, a success rate of 73 % (30/41) was achieved, with anatomical reduction of prolapse. For splinting and digitations, an 82 % cure rate was realized. The Pelvic Floor Distress Inventory (PFDI) pre- and post-operative results showed significant improvement (p < 0.001). There were two incisional exposures (5 %). Seventy percent of patients were secondary repairs while 30 % were primary repairs (81 % success rate, p < 0.36). One patient experienced nerve entrapment and subsequent unilateral takedown. Patient satisfaction was 77 %.

CONCLUSIONS

Our retrospective study approaching long-term results demonstrated that symptomatic rectocele procedures with human dermal allograft interposition provide an effective anatomical and functional repair with acceptable complication rates.

MicroRNA-92 expression may be associated with reduced estrogen receptor β1 mRNA levels in cervical portion of uterosacral ligaments in women with pelvic organ prolapse

OBJECTIVE

This study examined microRNA-92 (miR-92) expression level in relation to the mRNA level of its potential target gene, estrogen receptor β1 (ERβ1), in female patients diagnosed with pelvic organ prolapse (POP).

STUDY DESIGN

Between July 2012 and September 2014, a total of 104 patients were recruited at the First Affiliated Hospital of Sun Yat-sen University, which included 56 POP patients and 48 non-POP control subjects. Based on POP-Q score, the POP patients were further categorized into POP II and POP III groups. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to quantify miR-92 expression level. ERβ1 tissue expression was measured by western blot and immunohistochemistry (IHC) methods. SPSS 19.0 software was used for statistical analysis.

RESULTS

No remarkable differences were observed between the POP group and non-POP group, and between the POP II and POP III groups, with respect to age, body mass index (BMI), parity, menopause status, and family history of POP. The expression level of miR-92 in the POP group was dramatically higher than the non-POP group (P<0.05). Consistent with the disease status, miR-92 expression level in POP III group was markedly higher than the POP II group (P<0.05). Western blot analysis revealed significantly reduced levels of ERβ1 in the POP group compared to the non-POP group, with similar results obtained between the POP III and POP II groups (all P<0.05). IHC results showed ERβ1 staining mainly in the nucleus and semi-quantitative measurements, expressed as positive expression rate, revealed that ERβ1 level in the POP group was clearly lower than non-POP group. Finally, statistical analysis of IHC results from uterosacral ligament tissue showed inverse correlation between miR-92 and ERβ1 expression levels in POP patients (P<0.05).

CONCLUSIONS

Our results revealed increased miR-92 expression and decreased ERβ1 level in uterosacral ligaments of women diagnosed with POP, compared to non-POP subjects POP III patients exhibited more severe changes than POP II patients. Further, ERβ1expression is inversely correlated to miR-92 expression. Taken together, our results suggest that miR-92 and ERβ1 expression levels may be used as reliable diagnostic markers for assessing the severity of POP.

Elastin density: Link between histological and biomechanical properties of vaginal tissue in women with pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

The aim of the study was to correlate histological and biomechanical characteristics of the vaginal wall in women with pelvic organ prolapse (POP).

METHODS

Tissue samples were collected from the anterior [point Ba; POP Questionnaire (POP-Q)] and/or posterior (point Bp; POP-Q) vaginal wall of 15 women who underwent vaginal surgery for POP. Both histological and biomechanical assessments were performed from the same tissue samples in 14 of 15 patients. For histological assessment, the density of collagen and elastin fibers was determined by combining high-resolution virtual imaging and computer-assisted digital image analysis. For biomechanical testing, uniaxial tension tests were performed to evaluate vaginal tissue stiffness at low (C0) and high (C1) deformation rates.

RESULTS

Biomechanical testing highlights the hyperelastic behavior of the vaginal wall. At low strains (C0), vaginal tissue appeared stiffer when elastin density was low. We found a statistically significant inverse relationship between C0 and the elastin/collagen ratio (p = 0.048) in the lamina propria. However, at large strain levels (C1), no clear relationship was observed between elastin density or elastin/collagen ratio and stiffness, likely reflecting the large dispersion of the mechanical behavior of the tissue samples.

CONCLUSION

Histological and biomechanical properties of the vaginal wall vary from patient to patient. This study suggests that elastin density deserves consideration as a relevant factor of vaginal stiffness in women with POP.

Frequency and Determinants of Urinary Incontinence in Adolescent and Young Nulliparous Women

STUDY OBJECTIVE

To investigate the rate of urinary incontinence (UI) in a sample of young nulligravid women and its potential risk factors and consequences on life habits.

DESIGN AND PARTICIPANTS

The study is based on an online self-administered questionnaire taken by nulligravid women aged 15 to 25 years.

MEASUREMENTS

The Questionnaire for Urinary Incontinence Diagnosis and part of The King's Health Questionnaire. Demographics and general characteristics are also recorded.

RESULTS

We collected 1936 questionnaires (mean age of participants, 21 years); 12.4% of the sample reported any UI (95% confidence interval [CI] 10.9% to 13.9%). The estimated incidence of UI subtypes was 7.2% (95% CI 6.0% to 8.4%) stress UI, 3.4% (95% CI 2.6% to 4.3%) urge UI, and 1.9% (95% CI 1.3% to 2.6%) mixed UI. Age younger than 19 years and body mass index of 30 kg/m(2) or greater were associated in the multivariate analysis with an increased risk of UI. A self-reported history of psychological disorders increased the risk of UI (adjusted odds ratio [AOR] 1.4 and 95% CI 1.1% to 1.9%), without significant differences among the UI subtypes. A current history of constipation (AOR 1.9 and 95% CI 1.3% to 2.6%) and enuresis after the age of 5 also increased the risk of UI (AOR 2.9 and 95% CI 2.0% to 4.3%).

CONCLUSION

In a sample of young nulligravid women, UI was not associated with any chronic risk factor known for elder age, but a prevention program may be proposed to women because of their young age (eg, educational session to promote the proper functioning of the pelvic floor). More detailed analyses are needed to better assess the prevalence of UI and risk factors in young nulligravid women.

Cystocele and functional anatomy of the pelvic floor: review and update of the various theories

INTRODUCTION AND HYPOTHESIS

We updated anatomic theories of pelvic organ support to determine pathophysiology in various forms of cystocele.

METHODS

PubMed/MEDLINE, ScienceDirect, Cochrane Library, and Web of Science databases were searched using the terms pelvic floor, cystocele, anatomy, connective tissue, endopelvic fascia, and pelvic mobility. We retrieved 612 articles, of which 61 matched our topic and thus were selected. Anatomic structures of bladder support and their roles in cystocele onset were determined on the international anatomic classification; the various anatomic theories of pelvic organ support were reviewed and a synthesis was made of theories of cystocele pathophysiology.

RESULTS

Anterior vaginal support structures comprise pubocervical fascia, tendinous arcs, endopelvic fascia, and levator ani muscle. DeLancey's theory was based on anatomic models and, later, magnetic resonance imaging (MRI), establishing a three-level anatomopathologic definition of prolapse. Petros's integral theory demonstrated interdependence between pelvic organ support systems, linking ligament-fascia lesions, and clinical expression. Apical cystocele is induced by failure of the pubocervical fascia and insertion of its cervical ring; lower cystocele is induced by pubocervical fascia (medial cystocele) or endopelvic fascia failure at its arcus tendineus fasciae pelvis attachment (lateral cystocele).

CONCLUSIONS

Improved anatomic knowledge of vaginal wall support mechanisms will improve understanding of cystocele pathophysiology, diagnosis of the various types, and surgical techniques. The two most relevant theories, DeLancey's and Petros's, are complementary, enriching knowledge of pelvic functional anatomy, but differ in mechanism. Three-dimensional digital models could integrate and assess the mechanical properties of each anatomic structure.

Evidence for pelvic organ prolapse predisposition genes on chromosomes 10 and 17

OBJECTIVE

We conducted a genomewide linkage analysis to identify pelvic organ prolapse (POP) predisposition genes using a resource of high-risk POP pedigrees.

STUDY DESIGN

Cases are defined as women who reported bothersome symptoms of POP based on standardized symptom questions (Pelvic Floor Distress Inventory, moderately or quite bothered), and/or received treatment for POP documented in medical records. Our complete pedigree resource contains 299 familial POP cases in 83 high-risk pedigrees. Genotype data were obtained from Illumina HumanHap550, 610Q, the Human1M-Duo, Human Omni1-Quad, or the Human Omni 2.5 platforms. A set of single nucleotide polymorphism markers common to all platforms was identified and markers in high linkage disequilibrium were removed. We performed a genomewide linkage analysis under general dominant and recessive models using a Markov chain, Monte Carlo linkage analysis method implemented in MCLINK (University of Utah) software. Because 70 individuals in 32 pedigrees were used in a previously published linkage analysis for a phenotype of POP requiring treatment/surgery, we also performed linkage only including the 225 newly recruited and genotyped cases in 61 pedigrees.

RESULTS

Linkage analysis using our complete pedigree resource for the loosened criteria of bothersome POP showed evidence for significant genomewide linkage on chromosome 10q24-26 (recessive model, maximum heterogeneity logarithm of odds 3.4); suggestive evidence was identified on chromosomes 6 and 17, and an additional region on chromosome 10. In the subset of only the newly recruited familial POP cases, significant evidence for genomewide linkage was observed on chromosome 17q25 (recessive model, maximum heterogeneity logarithm of odds 3.3), and suggestive evidence for linkage was observed on chromosomes 10 and 11. Neither analysis duplicated the previously published linkage evidence for the POP requiring treatment/surgery phenotype observed on chromosome 9.

CONCLUSION

While the etiology of this common condition is unknown, this study provides evidence that loci on chromosomes 10q and 17q may contribute to POP etiology.

Evidence-based outcomes for mesh-based surgery for pelvic organ prolapse

PURPOSE OF REVIEW

In light of all the recent controversy regarding the use of synthetic mesh for pelvic organ prolapse, we did a retrospective review of the evidence-based outcomes and complications for its use.

RECENT FINDINGS

A total of 18 of the most recent studies in the last 5 years were selected. Studies selected were prospective randomized or quasi-randomized controlled trials that included surgical operations for pelvic organ prolapse for this review. Additionally, Cochrane review and meta-analysis of outcomes and complication were also analyzed. In terms of outcomes, the definition of successful surgery is currently being debated. Synthetic mesh provides superior anatomical and subjective cure rates compared with native tissue repair. Success rates varied greatly depending on the nature of prolapse and surgical approach. Furthermore, recurrence rates for mesh-based surgery are significantly lower than that for native tissue repair. The main unique complication of mesh is exposure and was reported in a mean of 11.4% of patients, with 6.8% of patients requiring surgical partial excision of mesh.

SUMMARY

Mesh significantly improves anatomical outcomes with sacrocolpopexy and vaginal repair. Mesh does create the unique complication which can be reduced with training and proper patient selection. Further development of better materials is vital rather than reverting to tissue-based repair. Ultimately, the decision to use mesh should be based upon a patient's personal goals and preferences after an informed conversation with her physician.

The effect of ascorbic acid and fluid flow stimulation on the mechanical properties of a tissue engineered pelvic floor repair material

Synthetic non-degradable meshes used in pelvic floor surgery can cause serious complications such as tissue erosion. A repair material composed of an autologous oral fibroblast seeded degradable polylactic acid scaffold may be a viable alternative. The aims of this study were to investigate the effects of media supplementation with additives (ascorbic acid-2-phosphate, glycolic acid and 17-β-oestradiol) on the mechanical properties of these scaffolds. Oral fibroblasts were isolated from buccal mucosa. The effects of the three additives were initially compared in two-dimensional culture to select the most promising collagen stimulating additive. Sterile electrospun scaffolds were seeded with 500,000 oral fibroblasts and fixed in 6-well plates and subjected to ascorbic acid-2-phosphate (the best performing additive) and/or mechanical stimulation. Mechanical stimulation by fluid shear stress was induced by rocking scaffolds on a platform shaker for 1 h/day for 10 of 14 days of culture. In two-dimensional culture, ascorbic acid-2-phosphate (concentrations from 0.02 mM to 0.04 M) and glycolic acid (10 µM) led to significantly greater total collagen production, but ascorbic acid-2-phosphate at 0.03 mM produced the greatest stimulation (of the order of >100%). In three-dimensional culture, mechanical stimulation alone gave non-significant increases in stiffness and strength. Ascorbic acid-2-phosphate (0.03 mM) significantly increased collagen production in the order 280% in both static and mechanically stimulated scaffolds (p < 0.0001). There was no additional effect of mechanical stimulation. Dense collagen I fibres were observed with ascorbic acid-2-phosphate supplementation. Uniaxial tensiometry showed that strength (p < 0.01) and stiffness (p <0.05) both improved significantly. A combination of ascorbic acid-2-phosphate and mechanical stimulation led to further non-signficant increases in strength and stiffness. In conclusion, a pelvic floor repair material with improved mechanical properties can be developed by supplementing culture media with ascorbic acid-2-phosphate to increase collagen I production. Future studies will assess the change in mechanical properties after implantation in an animal model.

Biaxial mechanical properties of swine uterosacral and cardinal ligaments

Mechanical alterations to pelvic floor ligaments may contribute to the development and progression of pelvic floor disorders. In this study, the first biaxial elastic and viscoelastic properties were determined for uterosacral ligament (USL) and cardinal ligament (CL) complexes harvested from adult female swine. Biaxial stress-stretch data revealed that the ligaments undergo large strains. They are orthotropic, being typically stiffer along their main physiological loading direction (i.e., normal to the upper vaginal wall). Biaxial stress relaxation data showed that the ligaments relax equally in both loading directions and more when they are less stretched. In order to describe the experimental findings, a three-dimensional constitutive law based on the Pipkin-Rogers integral series was formulated. The model accounts for incompressibility, large deformations, nonlinear elasticity, orthotropy, and stretch-dependent stress relaxation. This combined theoretical and experimental study provides new knowledge about the mechanical properties of USLs and CLs that could lead to the development of new preventive and treatment methods for pelvic floor disorders.

Differential expression profiling of matrix metalloproteinases and tissue inhibitors of metalloproteinases in females with or without pelvic organ prolapse

Pelvic organ prolapse (POP) is a common disorder that can disturb the health and quality of life of females. However, the basic pathophysiology and underlying mechanism of POP are not fully understood. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been reported to be associated with the onset and development of POP. In the present study, to characterize the differential expression profile of MMPs and TIMPs in female patients with and without POP, a total of 72 POP patients were sampled as a patient group and 72 non-POP patients that underwent hysterectomy due to benign tumors were sampled as a control group. Immunohistochemistry and polymerase chain reaction analysis were used to detect the expression levels of MMP-1, -2, -3 and -9 as well as TIMP-1 protein and mRNA in the anterior vaginal wall tissues. The expression levels of MMP-1, -2, -3 and -9 in the patient group were found to be significantly higher than those in the control group. By contrast, TIMP-1 expression levels in the patient group were significantly lower than those in the control group. Correlational analysis revealed a significantly positive correlation among the expression levels of MMP-2, -3 and -9. TIMP-1 expression levels were significantly negatively correlated with the expression levels of MMP-3 and -9. In addition, the expression levels of MMP-1 exhibited a positive correlation with those of MMP-2, -3 and -9, but a negative correlation with those of TIMP-1. The results demonstrated that the increased expression levels of MMPs and the reduced expression levels of TIMPs were directly associated with the presence of uterine prolapse, indicating that the differential expression levels of MMPs and TIMPs were correlated with the occurrence and development of POP. This data may assist in elucidating the molecular mechanism of MMP and TIMP involvement in POP, and also provide an underlying theoretical basis for the prevention and treatment of POP.

Recent studies of genetic dysfunction in pelvic organ prolapse: the role of collagen defects

Gynaecologists are becoming increasingly aware that women with a family history of prolapse are at an increased risk of prolapse refractory to treatment. In the past five years, several genetic mutations have been shown to correlate with increased prolapse susceptibility. These mutations can result in disordered collagen metabolism, which weaken the fascial support of the pelvic organs. This review examines the contemporary evidence regarding the role of collagen in prolapse.

Gender differences in bladder control: from babies to elderly

In both sexes, there are anatomical and behavioral differences in dealing with bladder control, as well as voiding and incontinence. Despite intensive research within the last decades, the differences in physiology and pathophysiology as well as gender differences of bladder control and continence are still poorly understood and further research is highly needed. In babies, gender difference seems to be most likely caused by a difference in maturity rate of the bladder. After gaining bladder control, behavior starts to be influenced by socialization. During preschool and school, children experience a negative perception of school toilets. Especially girls crouch over the toilet seat and train to empty the bladder without relaxation of the pelvic floor. This posture may lead to bladder dysfunction. Often adult women continue this bad habit and bladder dysfunction may consolidate. From the fourth decade in both sexes lower urinary tract symptoms start to develop. However, men and women handle the problem variedly showing gender differences in coping strategies with better coping mechanisms in women. In general, gender difference in help seeking and receiving treatment increases with younger age. In elderly, urinary incontinence is only associated with a higher mortality in men, and elderly men seek more often professional help. Aim of the review is to provide an insight into gender differences of bladder control and bladder dysfunction.

Are bony pelvis dimensions associated with levator ani defects? A case-control study

INTRODUCTION AND HYPOTHESIS

Bony pelvis dimensions have been shown to differ in women with and without pelvic floor dysfunction. The goal of this study was to determine whether bony pelvis dimensions are different when comparing women with severe bilateral levator ani defects (LAD) with those with normal muscles.

METHODS

This is a secondary analysis of a case-control study comparing women with and those without pelvic organ prolapse. Subjects underwent pelvic organ prolapse quantification (POP-Q) examination and were classified as either having prolapse or being normal. All underwent pelvic magnetic resonance imaging (MRI). Levator defects were assessed based on the muscles' appearance on imaging and subjects were stratified into two groups--women with normal muscles (n = 99) and women with severe bilateral LAD (n = 50). Bony pelvis dimensions were measured via MRI pelvimetry. The subpubic angle, interspinous and intertuberous diameters, and the sacrococcygeal joint-to-infrapubic point (SCIPP) lengths were compared.

RESULTS

Both groups had similar demographics. The SCIPP length was 2.5 % (3 mm) shorter in women with severe LAD than in those without defects (P = 0.02). The SCIPP measured 4 % (5 mm) less in women with prolapse and severe LAD than in subjects with prolapse but normal muscles (P = 0.01). Logistic regression identified SCIPP length and history of forceps delivery as being independent predictors of severe bilateral LAD.

CONCLUSIONS

Severe bilateral LAD are associated with shorter SCIPP length and forceps-assisted vaginal delivery.

Is cervical elongation associated with pelvic organ prolapse?

INTRODUCTION AND HYPOTHESIS

It is commonly believed that pelvic organ prolapse (POP) is associated with cervical elongation. However, cervical lengths have not been formally compared between women with prolapse and those with normal support.

METHODS

Cervix and uterine corpus lengths were measured on magnetic resonance images in a case-control study of 51 women with prolapse and 46 women with normal support determined by the Pelvic Organ Prolapse Quantification (POP-Q) examination. Group matching ensured similar demographics in both groups. Ranges for normal cervical lengths were determined from the values in the control group in order to evaluate for cervical elongation amongst women with prolapse.

RESULTS

The cervix is 36.4 % (8.6 mm) longer in women with prolapse than in women with normal pelvic support (p < 0.001). Linear regression modeling suggests the feature most highly associated with cervical length is the degree of uterine descent (POP-Q point C). Approximately 40 % of women with prolapse have cervical elongation; 57 % of cervical elongation in prolapse can be explained by a logistic regression-based model including POP-Q point C, body mass index, and menopausal status.

CONCLUSIONS

Cervical elongation is found in one third of women with POP, with the extent of elongation increasing with greater degrees of uterine descent.

Type I collagen and matrix metalloproteinase 1, 3 and 9 gene polymorphisms in the predisposition to pelvic organ prolapse

AIM

To evaluate whether the presence of specific polymorphism in the gene promoter of collagen and some matrix metalloproteinases was associated with the risk of developing pelvic organ prolapse.

METHODS

A case-control study was carried on 233 women: 137 were cases with ≥ stage II pelvic organ prolapse and 96 were matched controls without pelvic pathologies. Allele and genotype frequencies related to polymorphisms at the Sp1 site of type I collagen and some functional polymorphisms in the promoters of metalloproteinases-1, -3 and -9 have been compared between groups. It has been shown that these single-insertions/deletions polymorphisms located in the promoter region of the genes have a functional significance in the regulation of their transcriptional level and local expression. Genotypes were determined by polymerase chain reaction (PCR) amplification and sequence analysis. SPSS 14.0 software was used for data analysis. Probability values of <0.05 were considered statistically significant.

RESULTS

No difference between groups was found in the genotype distribution polymorphisms for COL1A1, metalloproteinases-9 and -3, while the distribution of the polymorphism of metalloproteinases-1 was significantly increased in the cases when compared with controls (p = 0.04).

CONCLUSIONS

Our findings suggest that the polymorphism of metalloproteinases-1 might have a role in mediating susceptibility to pelvic organ prolapse.