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

Single-cell analysis of uterosacral ligament revealed cellular heterogeneity in women with pelvic organ prolapse

Pelvic organ prolapse (POP) markedly affects the quality of life of women, including significant financial burden. Using single-cell RNA sequencing, we constructed a transcriptional profile of 30,452 single cells of the uterosacral ligament in POP and control samples, which has never been constructed before. We identified 10 major cell types, including smooth muscle cells, endothelial cells, fibroblasts, neutrophils, macrophages, monocytes, mast cells, T cells, B cells, and dendritic cells. We performed subpopulation analysis and pseudo-time analysis of POP primary cells, and explored differentially expressed genes. We verified previous cell clusters of human neutrophils of uterosacral ligaments. We found a significant reduction in receptor-ligand pairs related to ECM and cell adhesion between fibroblasts and endothelial cells in POP. The transcription factors related to the extracellular matrix, development, and immunity were identified in USL. Here we provide insight into the molecular mechanisms of POP and valuable information for future research directions.

A review on the recent applications of synthetic biopolymers in 3D printing for biomedical applications

3D printing technology is an emerging method that gained extensive attention from researchers worldwide, especially in the health and medical fields. Biopolymers are an emerging class of materials offering excellent properties and flexibility for additive manufacturing. Biopolymers are widely used in biomedical applications in biosensing, immunotherapy, drug delivery, tissue engineering and regeneration, implants, and medical devices. Various biodegradable and non-biodegradable polymeric materials are considered as bio-ink for 3d printing. Here, we offer an extensive literature review on the current applications of synthetic biopolymers in the field of 3D printing. A trend in the publication of biopolymers in the last 10 years are focused on the review by analyzing more than 100 publications. Their application and classification based on biodegradability are discussed. The various studies, along with their practical applications, are elaborated in the subsequent sections for polyethylene, polypropylene, polycaprolactone, polylactide, etc. for biomedical applications. The disadvantages of various biopolymers are discussed, and future perspectives like combating biocompatibility problems using 3D printed biomaterials to build compatible prosthetics are also discussed and the potential application of using resin with the combination of biopolymers to build customized implants, personalized drug delivery systems and organ on a chip technologies are expected to open a new set of chances for the development of healthcare and regenerative medicine in the future.

Effect of Surgically Induced Weight Loss on Pelvic Organ Prolapse: A Meta-analysis

INTRODUCTION

Bariatric surgery alleviates certain aspects of pelvic floor disorder, but the effect on pelvic organ prolapse (POP) is unclear. To assess the effect of bariatric surgery on POP we conducted the present meta-analysis and firstly performed a subgroup analysis based on the duration of follow-up.

METHODS

Four databases including PubMed, The Cochrane Library, Web of Science, and Embase were searched to identify relevant studies published before February 24, 2023. The main outcome was the prevalence and severity of POP symptoms before and after bariatric surgery. Then we assessed the heterogeneity, publication bias and performed subgroup analyses based on follow-up time, study quality and region.

RESULTS

Eleven studies with a total of 696 participants met the inclusion criteria. The results showed that the prevalence of POP decreased after bariatric surgery (odds ratio[OR] = 2.29, 95% confidence interval[CI]: 1.05, 5.01; P = 0.04, I2 = 78%), with significant differences observed both at 3-6 months (OR = 2.24, 95% CI: 1.25, 4.01; P = 0.007, I2 = 59%) and 12 months (OR = 4.64, 95% CI: 2.83, 7.58; P < 0.0001, I2 = 0%) of follow-up compared with pre-surgery. Pelvic Organ Prolapse Distress Inventory scores 6-item also decreased after bariatric surgery (mean difference [MD] = 2.11, 95% CI: 0.32, 3.89; P = 0.02, I2 = 55%) with significant differences observed both at 3-6 months (MD = 3.72; 95% CI: [0.10, 7.34], P = 0.04, I2 = 70%) and ≥ 12 months (MD = 3.24; 95% CI: [0.56, 5.91], P = 0.02, I2 = 56%) of follow-up.

CONCLUSION

Bariatric surgery alleviated POP symptoms in women with obesity both during short-term (3-6 months) and long-term (≥ 12 months) follow-up.

Study of pelvic organ prolapse as a predictor of osteoporotic fracture risk

Purpose: The present study aimed to examine the association between the stage of pelvic organ prolapse (POP) and the risk of fracture in postmenopausal women.Methods: A cross-sectional design was used, which included 133 women with POP over 50 years of age. The participants were classified according to their POP stage, underwent blood tests (hemogram, biochemistry, bone remodeling markers, and hormone tests), and completed a sociodemographic and lifestyle questionnaire along with densitometry, FRAX, and FRIDEX tests.Results: Of the 133 women studied, 66 presented stages I-II POP (49.6%) and 67 III-IV POP (50.4%). The mean age of the participants was 64.47 years. Women with a high POP stage showed higher FRAX scores for major osteoporotic and hip fracture (p .001 and p < .001p). Bivariate analysis revealed that higher scores on the FRIDEX scale were associated with a higher POP stage (p = .032). In addition, there was a marginally significant negative association between bone mineral density (BMD) and POP stage (p = .054).Conclusions: High-stage POP can be considered an independent predictor of osteoporotic fracture risk, as measured using the FRAX and FRIDEX scales.

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

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

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

The difference in collagen type-1 expression in women with and without pelvic organ prolapse: a systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

This study was aimed at identifying the difference in collagen type-1 expression in women with and without pelvic organ prolapse (POP).

METHODS

A systematic review and meta-analysis was carried out women with and without pelvic organ prolapse. This meta-analysis was conducted on research articles describing the evaluation of collagen type-1 expression between patients with and without POP. The articles were obtained from PubMed, EBSCO, and ProQuest, and were published between January 2000 and June 2021. Pooled mean difference (MD) and pooled odds ratio (OR) were calculated using fixed effect models. Review Manager (RevMan 5.4) was used to analyze the data. The main outcome measures were pooled MD and pooled OR of collagen type-1 expression in patients with and without POP.

RESULTS

A total of seven case-control studies were included in the meta-analysis using the effect size of the MD and two case-control studies were included in the meta-analysis using the effect size of the OR. A total of 247 POP cases and 132 non-POP cases were identified from the studies. Our study indicated that patients with POP had a lower level of collagen type-1 expression than non-POP patients (MD = -6.77; 95% CI: -8.37, -5.17, p < 0.00001). Patients with low expression of collagen type-1 in pelvic support tissue are at a more than 3 times higher risk of suffering from pelvic organ prolapse (OR = 3.23, 95% CI: 1.52 to 6.87, p = 0.002).

CONCLUSION

The results of this study showed that patients with pelvic organ prolapse have lower expression of collagen type-1 than nonpelvic organ prolapse patients.

“Locus minoris resistentiae” and connective tissue weakness in older women: a case report and literature review on pelvic organ prolapse with inguinal bladder hernia

Background

Conditions such as genital prolapse and hernia are known to be related to connective tissue dysfunction. In this report on cases of the rare simultaneous finding of large genital prolapse and post-prolapse repair female inguinal bladder hernia, we aim to contribute to the discussion of a possible clinical definition of connective tissue weakness, for its clinical assessment and preoperative patient counselling.

Case presentation

Three cases of medial third-grade (MIII, Aachen classification) inguinal bladder hernia developing or enlarging after successful stage-IV pelvic organ prolapse (POP) repair at a university pelvic floor centre are presented. All patients were aged ≥ 80 years with long-standing postmenopausal status. One patient was followed for 5 years and two patients were followed for 6 months. In all patients, ultrasound revealed that the hernia sac contained the urinary bladder, which had herniated through the inguinal hernia orifice. A literature search revealed only one case report of direct female inguinal bladder hernia and few investigations of the simultaneous occurrence of POP and hernia in general.

Conclusion

The simultaneous occurrence of inguinal hernia and female POP can lead to bladder herniation following prolapse surgery in the sense of a “locus minoris resistentiae”. Clinical examination for simultaneous signs of connective tissue weakness and counselling prior to pelvic reconstructive surgery could help to increase patients’ compliance with further surgical treatment for hernia.

Effects of Oxytocin for Induction and Augmentation of Labor on Pelvic Floor Symptoms and Support in the Postpartum Period

OBJECTIVE

The aim of the study was to determine whether oxytocin for induction or augmentation of labor impacts the incidence or persistence of pelvic floor symptoms and support 5 to 10 weeks after first vaginal delivery.

METHODS

Participants in this prospective cohort study were nulliparous women 18 years or older that delivered vaginally at 37 weeks gestation or more and completed the Epidemiology of Prolapse and Incontinence Questionnaire (EPIQ) and the Pelvic Organ Prolapse Quantification examination in third trimester and 5 to 10 weeks postpartum. We compared the incidence and persistence of symptomatic EPIQ domains and worse vaginal support (maximal vaginal descent ≥0 cm) between women who received oxytocin with those that did not (with or without prostaglandin or mechanical methods in both groups). We performed modified binomial regression to calculate adjusted relative risks of each outcome with 95% confidence intervals.

RESULTS

The mean (SD) age of the 722 participants was 28.3 (5.2) years; 20% were Hispanic. There were no significant differences according to oxytocin exposure in either incidence or persistence of symptomatic EPIQ domains or worse vaginal support. We found similar results in sensitivity analyses comparing women who received oxytocin as the sole pharmacologic agent to women who received no pharmacologic agent. After adjusting for demographic and obstetric factors associated with incidence and persistence of symptoms and support, oxytocin exposure continued to have no effect.

CONCLUSIONS

Oxytocin during labor does not significantly increase the risks for the incidence or persistence of pelvic floor symptoms or worse vaginal support in the early postpartum period, although power for less frequent outcomes was limited.

COL3A1 rs1800255 polymorphism is associated with pelvic organ prolapse susceptibility in Caucasian individuals: Evidence from a meta-analysis

Background

The collagen 3 alpha 1 (COL3A1) rs1800255 polymorphism has been reported to be associated with women pelvic organ prolapse (POP) susceptibility, but the results of these previous studies have been contradictory. The objective of current study is to explore whether COL3A1 rs1800255 polymorphism confers risk to POP.

Methods

Relevant literatures were searched by searching databases including Pubmed, Embase, Google academic, the Cochrane library, China National Knowledge Infrastructure (CNKI). Search time is from database foundation to March 2021.

Results

A total of seven literatures were enrolled in the present meta-analysis, including 1642 participants. Overall, no significant association was found by any genetic models. In subgroup analysis based on ethnicity, significant associations were demonstrated in Caucasians by allele contrast (A vs. G: OR = 1.34, 95%CI = 1.03–1.74,), homozygote comparison (AA vs. GG: OR = 3.25, 95%CI = 1.39–7.59), and recessive genetic model (AA vs. GG/GA: OR = 3.22, 95%CI = 1.40–7.42).

Conclusions

The present meta-analysis suggests that the COL3A1 is a candidate gene for POP susceptibility. Caucasian individuals with A allele and AA genotype have a higher risk of POP. The COL3A1 rs1800255 polymorphism may be risk factor for POP in Caucasian population.

Single-cell transcriptome profiling of the vaginal wall in women with severe anterior vaginal prolapse

Anterior vaginal prolapse (AVP) is the most common form of pelvic organ prolapse (POP) and has deleterious effects on women's health. Despite recent advances in AVP diagnosis and treatment, a cell atlas of the vaginal wall in AVP has not been constructed. Here, we employ single-cell RNA-seq to construct a transcriptomic atlas of 81,026 individual cells in the vaginal wall from AVP and control samples and identify 11 cell types. We reveal aberrant gene expression in diverse cell types in AVP. Extracellular matrix (ECM) dysregulation and immune reactions involvement are identified in both non-immune and immune cell types. In addition, we find that several transcription factors associated with ECM and immune regulation are activated in AVP. Furthermore, we reveal dysregulated cell-cell communication patterns in AVP. Taken together, this work provides a valuable resource for deciphering the cellular heterogeneity and the molecular mechanisms underlying severe AVP.

Role of sex steroid hormones in pelvic organ prolapse

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Genome-wide association identifies seven loci for pelvic organ prolapse in Iceland and the UK Biobank

Pelvic organ prolapse (POP) is a downward descent of one or more of the pelvic organs, resulting in a protrusion of the vaginal wall and/or uterus. We performed a genome-wide association study of POP using data from Iceland and the UK Biobank, a total of 15,010 cases with hospital-based diagnosis code and 340,734 female controls, and found eight sequence variants at seven loci associating with POP (P < 5 × 10-8); seven common (minor allele frequency >5%) and one with minor allele frequency of 4.87%. Some of the variants associating with POP also associated with traits of similar pathophysiology. Of these, rs3820282, which may alter the estrogen-based regulation of WNT4, also associates with leiomyoma of uterus, gestational duration and endometriosis. Rs3791675 at EFEMP1, a gene involved in connective tissue homeostasis, also associates with hernias and carpal tunnel syndrome. Our results highlight the role of connective tissue metabolism and estrogen exposure in the etiology of POP.

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.

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.

Composite mesh design for delivery of autologous mesenchymal stem cells influences mesh integration, exposure and biocompatibility in an ovine model of pelvic organ prolapse

The widespread use of synthetic transvaginal polypropylene mesh for treating Pelvic Organ Prolapse (POP) has been curtailed due to serious adverse effects highlighted in 2008 and 2011 FDA warnings and subsequent legal action. We are developing new synthetic mesh to deliver endometrial mesenchymal stem cells (eMSC) to improve mesh biocompatibility and restore strength to prolapsed vaginal tissue. Here we evaluated knitted polyamide (PA) mesh in an ovine multiparous model using transvaginal implantation and matched for the degree of POP. Polyamide mesh dip-coated in gelatin and stabilised with 0.5% glutaraldehyde (PA/G) were used either alone or seeded with autologous ovine eMSC (eMSC/PA/G), which resulted in substantial mesh folding, poor tissue integration and 42% mesh exposure in the ovine model. In contrast, a two-step insertion protocol, whereby the uncoated PA mesh was inserted transvaginally followed by application of autologous eMSC in a gelatin hydrogel onto the mesh and crosslinked with blue light (PA + eMSC/G), integrated well with little folding and no mesh exposure. The autologous ovine eMSC survived 30 days in vivo but had no effect on mesh integration. The stiff PA/G constructs provoked greater myofibroblast and inflammatory responses in the vaginal wall, disrupted the muscularis layer and reduced elastin fibres compared to PA + eMSC/G constructs. This study identified the superiority of a two-step protocol for implanting synthetic mesh in cellular compatible composite constructs and simpler surgical application, providing additional translational value.

Polymorphism rs1800255 from COL3A1 gene and the risk for pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Genetic variations of type III collagen may compromise the supportive structures of the female pelvic floor and consequently favor pelvic organ prolapse. The single nucleotide polymorphism G/A rs1800255 located in the coding region for type III collagen (COL3A1) was evaluated as a risk factor for pelvic organ prolapse.

METHODS

A single-center prospective cohort study including women with clinical diagnosis of stage III and IV prolapse (POP group) and prolapse stage 0 or I (control group). Sociodemographic, clinical data and obstetric history were retrieved by physician interview. DNA including the rs1800255 polymorphism was amplified by polymerase chain reaction from blood genomic cells and digested with AluI restriction enzyme for distinction of G and A variants. Qualitative variables were compared using the chi-square and Fisher's exact tests and unpaired t-test for quantitative variables. After stratification of the groups, risk factors for POP were estimated using odds ratios (ORs) from the binary logistic regression model.

RESULTS

A total of 292 women were included, 112 in the POP group and 180 in the control group. There was no significant difference between groups regarding rs1800255. Age and home birth were the only significant risk factors for pelvic organ prolapse.

CONCLUSION

Polymorphism rs1800255 from COL3A1 gene was not a risk factor for pelvic organ prolapse.

Transcriptional Regulation of Connective Tissue Metabolism Genes in Women With Pelvic Organ Prolapse

OBJECTIVE

The aim of this study was to compare differences in expressions and relationships between key genes involved in extracellular matrix metabolism and tissue cellularity in women with and without pelvic organ prolapse (POP).

METHODS

A total of 80 biopsies (anterior cuff, posterior cuff, and/or leading edge) were obtained from 30 women: n = 10 premenopausal without POP (controls), n = 10 premenopausal with POP, and n = 10 postmenopausal with POP. Quantitative reverse-transcriptase polymerase chain reaction was used to assess gene expression of bone morphogenetic protein 1 (BMP1), collagen types I (COL1) and III (COL3), relaxin family peptide receptor 1 (RXFP1), matrix metallopeptidase 2, and TIMP metallopeptidase inhibitors 2 and 3. Hematoxylin and eosin staining was used to assess cellularity of the connective tissue layer. Kruskal-Wallis test, Mann-Whitney U test, Pearson correlation, or linear regression analyses were used, as appropriate.

RESULTS

Bone morphogenetic protein 1 expression was significantly up-regulated in patients with POP compared with controls. Bone morphogenetic protein 1 expression was correlated with COL1 expression in all groups but only correlated with TIMP metallopeptidase inhibitor 3 expression in controls. Similarly, COL3 expression was correlated with RXFP1 expression in women with POP but not in controls. The degree of dependence (slope of the regression line) between COL1 and COL3 expressions was significantly elevated in premenopausal women with POP compared with the other 2 groups. The slopes between COL1-COL3, COL3-matrix metallopeptidase 2, COL1-RXFP1, and COL3-RXFP1 expressions were significantly lower in postmenopausal women compared with premenopausal women with POP. No differences were found in overall tissue cellularity.

CONCLUSIONS

Bone morphogenetic protein 1 expression may play a significant role in the pathophysiology of POP. The finding that BMP1 expression was correlated with COL1 expression in all groups suggests a conserved association between BMP1 and collagen synthesis in the vaginal wall. The elevated slope between COL1 and COL3 expressions may be associated with early (premenopausal) development of POP. The expression of RXFP1 in postmenopausal women and its altered intergene regulation suggests a role for RXFP1 in connective tissue metabolism outside pregnancy.

The effect of estrogen on tendon and ligament metabolism and function

Tendons and ligaments are crucial structures inside the musculoskeletal system. Still many issues in the treatment of tendon diseases and injuries have yet not been resolved sufficiently. In particular, the role of estrogen-like compound (ELC) in tendon biology has received until now little attention in modern research, despite ELC being a well-studied and important factor in the physiology of other parts of the musculoskeletal system. In this review we attempt to summarize the available information on this topic and to determine many open questions in this field.

Advanced glycation end products decrease collagen I levels in fibroblasts from the vaginal wall of patients with POP via the RAGE, MAPK and NF-κB pathways

The present study was carried out to observe the impact of advanced glycation end products (AGEs) on collagen I derived from vaginal fibroblasts in the context of pelvic organ prolapse (POP), and explore the downstream effects on MAPK and nuclear factor-κB (NF-κB) signaling. After treating primary cultured human vaginal fibroblasts (HVFs) derived from POP and non-POP cases with AGEs, cell counting was carried out by sulforhodamine B. The expression levels of collagen I, receptor of advanced glycation end products (RAGE), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were detected by western blot analysis and PCR. RAGE, MAPK and NF-κB were molecularly and pharmacologically-inhibited by siRNA, SB203580 and PDTC, respectively, and downstream changes were detected by western blot analysis and PCR. Inhibition of HVF proliferation by AGEs occurred more readily in POP patients than that noted in the controls. After treatment with AGEs, collagen I levels decreased and MMP-1 levels increased to a greater extent in the HVFs of POP than that noted in the controls. During this same period, RAGE and TIMP-1 levels remained stable. Following treatment with AGEs and RAGE pathway inhibitors by siRNA, SB203580 and PDTC, the impact induced by AGEs was diminished. The inhibition of p-p38 MAPK alone was not able to block the promoting effect of AGEs on the levels of NF-κB, which suggests that AGEs may function through other pathways, as well as p-p38 MAPK. On the whole, this study demonstrated that AGEs inhibited HVF proliferation in POP cases and decreased the expression of collagen I through RAGE and/or p-p38 MAPK and NF-κB-p-p65 pathways. Our results provide important insights into the collagen I metabolism in HVFs in POP.

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.

Biocompatibility of polypropylene mesh scaffold with adipose-derived stem cells

In this study, we investigated the rejection of the synthetic patch and human tissues in the host. We observed the growth of adipose-derived stem cells (ADSCs) cultured with polypropylene mesh in vitro. The results of flow cytometry showed that the expression of CD44, CD73, CD90, CD45, CD14 and CD34 was 98.54, 95.32, 98.49, 1.21, 3.01 and 2.14%, respectively. ADSCs were isolated from rabbit subcutaneous adipose tissue after collagenase digestion, filtration and centrifugation. The ADSCs of passage 3 were seeded onto the polypropylene mesh scaffolds. New Zealand White female breeder rabbits were implanted with polypropylene mesh, ADSC-fixed polypropylene mesh in the abdomen. After 4 weeks, adhesion was performed and the erosion of the mesh was evaluated. It was found that polypropylene mesh, ADSC-fixed polypropylene mesh all had different degrees of corrosion, and adhesion, but polypropylene mesh was more corroded. ADSC-fixed polypropylene mesh induced a milder chronic inflammation response compared with polypropylene, had significantly lower scores for inflammation (t=11.083), and had significantly higher scores for neovascularization (t=14.362) and fibroblastic proliferation (t=15.979). The relative amount of VEGF mRNA was significantly lower for ADSC-fixed polypropylene compared with the other polypropylene meshes (t=94.6). In conclusion, polypropylene mesh scaffold with ADSCs exhibit excellent cellular compatibility and are promising in clinical practice.

Identification of Differentially Expressed Genes in Pelvic Organ Prolapse by RNA-Seq

Background

Pelvic organ prolapse (POP) brings major health issues for women, affecting 40% of postmenopausal women, and directly affects bladder and bowel function, as well as quality of life. In light of the projected growth in demand for care for pelvic floor disorders, determining the etiology and progression of POP has important public health implications.

Material/Methods

Uterosacral ligaments (USLs) samples of POP patients and normal controls were enrolled for RNA-Seq, and functional annotation analysis and Protein-Protein interaction (PPI) networks construction were performed for differentially expressed genes (DEGs).

Results

A total of 81 DEGs were identified between POP and normal control, and distinctly classify all samples into normal and POP group by hierarchical clustering. Sixty-six DEGs demonstrated the same expression pattern among the POP samples with different stages. For those DEGs, canonical Wnt receptor signaling pathway was the most significantly enriched GO term (P value=3.33E-07), and neuroactive ligand-receptor interaction was the most significantly enriched pathway (P value=1.24E-03). In The PPI networks of 81 dysregulated genes, significant hub proteins contained TOP2A (Degree=54), KCNA5 (Degree=22) and PLA2G2A (Degree=19), suggesting their important role in the development of POP.

Conclusions

This RNA-seq analysis identified a POP signature of 81 genes, and some ECM-related genes, including COMP, NDP, and SNAI2 might participate in the pathology of POP and be applied as potential therapeutic targets.

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.