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

Potential molecular targets for intervention in pelvic organ prolapse

Pelvic organ prolapse (POP) is a concerning gynecological benign illness in middle-aged and senior women. Its etiology is complex, the incidence rate is high, symptoms are clinically subjective, and its influence tends to be polarized. At present, for those who need medical treatment, whether surgical or non-surgical, complications cannot be ignored, and treatment effect needs to be optimized. However, there is a lack of accurate molecular biological interventions for the prevention, diagnosis, progression delay, and treatment of POP. Here, we reviewed the current state of understanding of the molecular mechanisms and factors associated with POP etiology. These factors include cyclins, matrix metal peptidases/tissue inhibitors of metalloproteinases, microRNAs, homeobox A11, transforming growth factor β1, insulin-like growth factor 1, fibulin 5, lysyl oxidase-like 1, oxidative stress, inflammatory response, estrogen, and other potential biomarkers associated with POP. In addition, relevant molecular targets that may be used to intervene in POP are summarized. The aim of this review was to provide more information to identify accurate potential biomarkers and/or molecular targets for the prevention, diagnosis, progression delay, and treatment of POP, with the goal of improving medical treatment for patients at-risk for POP or having POP. Continued research is needed to identify additional details of currently accepted molecular mechanisms and to identify additional mechanisms that contribute to POP.

The polymorphisms of extracellular matrix-remodeling genes are associated with pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Extracellular matrix (ECM) synthesis and metabolism abnormalities may influence the pelvic supporting system and lead to the occurrence and development of pelvic organ prolapse (POP). Genetic polymorphisms of such related genes have been increasingly studied. This study aims to explore the association between the single-nucleotide polymorphisms (SNPs) of genes encoding ECM processing enzymes (a disintegrin and metalloproteinase with thrombospondin motifs [ADAMTSs]), ECM degrading enzymes (matrix metalloproteinases [MMPs]) and their tissue inhibitors of metalloproteinase (TIMPs), and POP.

METHODS

We conducted an association study including 48 women with POP at stages III and IV and 48 women without prolapse in Chinese groups. SNPs were identified using the target region sequencing technique. We performed Fisher's exact tests to assess the association between SNPs and POP in the unadjusted model and logistic regression analysis in the adjusted model, adjusting for delivery and pregnancy.

RESULTS

There was a significant association between TIMP2 SNP rs2277698 (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.16-0.82; P = 0.015), ADAMTS13 SNP rs149586801 (OR, 0.18; 95% CI, 0.05-0.69; P = 0.012), and ADAMTS1 SNPs rs370850 and rs422803 (OR, 3.71; 95% CI, 1.35-10.15; P = 0.011 for both), rs402007, rs428785, rs434857, and rs445784 (OR, 2.18; 95% CI, 1.05-4.56; P = 0.038 for the four), and POP in the adjusted model.

CONCLUSION

TIMP2, ADAMTS13, and ADAMTS1 might be candidate genes for POP. Our results provide preliminarily new evidence for future investigation of these genes in the pathophysiology of POP.

Advances in molecular mechanisms of pelvic organ prolapse (Review)

Pelvic organ prolapse (POP) is a common gynecological benign disease occurring in middle-aged and elderly females. Its incidence increases every year. To date, the majority of studies investigating its etiology have not evaluated the underlying molecular mechanisms, which has caused substantial difficulties in the prevention, treatment and prognosis of POP. In the present narrative review, recent research studies concerning the molecular mechanisms of POP were systematically reviewed and the advances were summarized. The association between the incidence of POP and the reduction of the extracellular matrix, activation of oxidative stress, genetic susceptibility, denervation of the pelvic floor and reduction of estrogen infiltration were explored. POP is mainly associated with damage of pelvic floor muscles and connective tissue, which are directly caused by pregnancy and vaginal delivery. The majority of the molecular and genetic mutations associated with POP involve specific components of connective tissue synthesis and degradation. It is likely that macroscopic parameters, such as anatomy, lifestyle and reproductive factors, interact with microscopic parameters, such as physiology and genetics in the female pelvic floor, leading to POP. Additional research studies investigating the molecular mechanisms of POP should be performed, since they may aid public health strategies. In the present narrative review, a summary of these molecular mechanisms underlying the development of POP is provided. This included the relevant proteins and genes involved. On this basis, countermeasures were proposed.

Systematic review and meta-analysis of genetic association studies of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

Family and twin studies demonstrate that pelvic organ prolapse (POP) is heritable, but the genetic etiology is poorly understood. This review aimed to identify genetic loci and specific polymorphisms associated with POP, while assessing the strength, consistency, and risk of bias among reported associations.

METHODS

Updating an earlier systematic review, PubMed and HuGE Navigator as well as relevant conference abstracts were searched using genetic and phenotype keywords from 2015 to 2020. Screening and data extraction were performed in duplicate. Fixed and random effects meta-analyses were conducted using co-dominant models of inheritance. We assessed credibility of pooled associations using interim Venice criteria.

RESULTS

We screened 504 new abstracts and included 46 published and 7 unpublished studies. In pooled analyses we found significant associations for four polymorphisms: rs2228480 at the ESR1 gene (OR 0.67 95% CI 0.46-0.98, I² = 0.0%, Venice rating BAB), rs12589592 at the FBLN5 gene (OR 1.46 95% CI 1.11-1.82, I² = 36.3%, Venice rating BBB), rs484389 in the PGR gene (OR 0.61 95% CI 0.39-0.96, I² = 32.4%, Venice rating CBB), and rs1800012 at the COL1A1 gene (OR 0.80 95% CI 0.66-0.96, I² = 0.0%, Venice rating BAB). Further credible novel variants have also been recently identified in genome-wide association studies.

CONCLUSION

The genetic contributions to POP remain poorly understood. Several biologically plausible variants have been identified, but much work is required to establish the role of these genes in the pathogenesis of POP or to establish a role for genetic testing in clinical practice.

SMAD2, SMAD3 and TGF-β GENE expressions in women suffering from urge urinary incontinence and pelvic organ prolapse

We evaluated the changes in the levels of TGF-β and SMAD gene and protein expression in the uterosacral ligament (USL) of patients with concomitant pelvic organ prolapse (POP) and urgency urinary incontinence (UUI) to illuminate the pathophysiology of UUI. The TGF-β pathway is involved in collagen synthesis and degradation. The Transforming Growth Family-β (TGF-β) superfamily has essential intracellular signaling components, such as newly identified SMAD family members. We evaluated the changes in the levels of TGF-β and SMAD gene and protein expression in the USL of patients with concomitant pelvic organ prolapse (POP) and UUI. This study included 10 patients who had been diagnosed with POP and UUI in the study group and 14 asymptomatic women without complaints of POP and UUI in the control group. Biopsy samples were collected from bilateral USL tissues during vaginal or abdominal hysterectomy. Total RNA was extracted from USL tissue and analyzed by qPCR. The protein expression levels were also analyzed with ELISA. In UUI patients, SMAD3 and TGF-ß1 gene expression levels significantly decreased compared to the control patients (p = 0.008 and p = 0.006, respectively). SMAD2 mRNA levels did not differ between the study and control groups (p = 0.139). No differences was found in the levels of SMAD2, SMAD3, and TGF-ß1 protein expression between the two groups. The reduction in the gene and protein expression levels of SMAD3 and TGF-ß1 in women with UUI and lax uterosacral ligaments may indicate a causal link.Clinical trial registration: NCT04525105.

The Role of Obstetric Factors, miRNA-30d and miRNA-181a in Postpartum Women with Pelvic Organ Prolapse

Background

The diagnosis of postpartum pelvic organ prolapse (POP) relies on symptoms combined with pelvic organ prolapse-quantification (POP-Q) and lacks serological indicators. The objective of this study was to assess serum elastin, type I collagen, miRNA-30d, and miRNA-181a in the early postpartum period to identify hematologic predictors of POP.

Material and Methods

The study included 1013 42- to 60-day-postpartum women who had delivered at Quanzhou Women's and Children's Hospital from October 1, 2016, to October 31, 2017. This study was performed in accordance with the Declaration of Helsinki. The pregnancy and childbirth characteristics and pelvic floor function were evaluated. Forty cases with and without POP were matched, and serum elastin and type I collagen were determined by enzyme-linked immunosorbent assay (ELISA). Reverse-transcription polymerase chain reaction (RT-PCR) was used to detect miRNA-30d and miRNA-181a in 15 pairs.

Results

Of the 1013 women recruited, 699 (69.00%) were diagnosed with POP. The mean age was 29.00 years old, and the mean body mass index (BMI) was 22.6 kg/m². In the univariate analysis, age ≥35 years (OR, 1.449; 95% CI, 0.965, 2.298), postpartum BMI ≥ 24 (OR, 4.402; 95% CI, 2.657, 6.148), neonatal weight ≥4 kg (OR, 4.832; 95% CI, 1.373, 17.290) and vaginal delivery (OR, 2.751; 95% CI, 1.855, 4.081) were risk factors for postpartum POP. There were no significant differences in the concentrations of serum elastin and type I collagen between the groups (P=0.52; P=0.26). There were significant differences in the concentrations of miRNA-30d and miRNA-181a between the groups (P=0.004; P=0.003).

Conclusion

miRNA-30d and miRNA-181a tended to be increased in women with POP and could be potential clinical predictors.

Collagen I and collagen III polymorphisms in women with pelvic organ prolapse

AIMS

Verify the presence of the single nucleotide polymorphisms rs1800012 of the collagen I (COL1A1) and rs1800255 of the collagen III (COL3A1) genes and their association with pelvic organ prolapse (POP) in Brazilian women and to determine risk factors for POP.

METHODS

We assessed 826 postmenopausal women divided into POP (stages III and IV) and control groups (stages 0 and I) by examination and peripheral blood sample collection. DNA sequences of interest were analyzed by real-time reverse-transcriptase polymerase chain reaction. We used logistic regression analyses, recessive and codominance models of inheritance, and P < .05 for significance.

RESULTS

Six-hundred and thirty-four postmenopausal women were included: 348 (54.8%) POP cases and 286 (45.1%) controls. The frequencies of GG, GA, and AA genotypes for COL1A1 were 69.12%, 20.24%, and 10.59% in POP group and 71.79%, 20%, and 8.21% in controls; GG, GT, and TT for COL3A1 were 37.54%, 59.53%, and 2.93% in POP group and 36.24%, 60.14%, and 3.62% in controls. There were no genotypic or allelic association with POP phenotype that link both SNPs rs1800012 and rs1800255 to increased risk of POP. Vaginal delivery (odds ratio [OR] = 13; 95% confidence interval [CI] [4.00-47.08]), POP family history (OR = 3.1; 95% CI [1.49-6.50]), diabetes mellitus (OR = 2.3; 95% CI [1.08-5.21]), number of pregnancies (OR = 1.2; 95% CI [1.05-1.36]), and age (OR = 1.1; 95% CI [1.09-1.19]), were variables of increased risk for POP (P < .05 for all).

CONCLUSION

Our study suggests lack of association between DNA polymorphisms rs1800012 of COL1A1 and rs1800255 of COL3A1 with advanced POP. Vaginal delivery, POP family history, diabetes mellitus, number of pregnancies, and age are risk factors for POP.

Common variants in LAMC1 confer risk for pelvic organ prolapse in Chinese population

BACKGROUND

Pelvic organ prolapse (POP) affects around 15% of postmenopausal women in China. Although it has been widely accepted that genetic variants could confer risk for POP, the genetic susceptibility variants remain largely unknown. Previous studies indicated that LAMC1, which encodes the laminin gamma 1 chain and is critical for extracellular matrix, might be a susceptibility gene for POP. The study is to test the correlation of common variants across the LAMC1 gene with POP susceptibility in Chinese population.

METHODS

A total of 396 individuals, including 161 unrelated patients of POP and 235 healthy controls, were recruited. Ten SNPs, including rs20558, rs20563, rs10911193, rs6424889, rs10911241, rs3768617, rs12073936, rs729819, rs10911214 and rs869133, of LAMC1, were genotyped using standard Sanger sequencing. The UNPHASED program (version 3.1.5) was used to analyze the genotyping data for allelic and genotypic associations.

RESULTS

SNP rs10911241 was significantly associated with POP risk (χ² = 10.70, P = 1.1 E-03). The minor allele (rs10911241-G) carriers exhibited an increased risk of the disease (OR = 1.71, 95% CI = 1.24-2.36).

CONCLUSION

Association of LAMC1 with POP risk in Chinese population strongly supported the involvement of LAMC1 in POP development.

Genetic polymorphisms in collagen-related genes are associated with pelvic organ prolapse

OBJECTIVE

Pelvic organ prolapse (POP) is a common health issue that has a profound negative influence on women's quality of life. Genetic susceptibility to POP has been increasingly investigated. In this study, we assessed the single-nucleotide polymorphisms (SNPs) of six collagen-related genes (COL14A1, COL5A1, COL4A2, COL3A1, COL1A1, and COL18A1) and the genetic association with POP in Chinese women.

METHODS

We performed a candidate gene association study of case women (n = 48) with stage III and IV prolapse and control women (n = 48) without prolapse. A target region sequencing approach was used to identify the SNPs in collagen-related genes. The association between SNPs and POP was examined by Fisher exact tests for unadjusted model and logistic regression analysis adjusted for delivery and pregnancy.

RESULTS

There was a significant association between COL14A1 SNPs (rs4870723, rs2305600, and rs2305598; P = 0.013, 0.019, and 0.028, respectively), a COL5A1 SNP (rs3827852; P = 0.016), and COL4A2 SNPs (rs76425569, rs388222, and rs2281968; P = 0.049 for the three, and rs445348, P = 0.040) and POP, respectively. Although there was no significant association between the COL3A1 SNP and POP, there was a trend toward significance for COL14A1 SNP (rs2305603), COL4A2 SNP (rs74941798), two COL1A1 SNPs (rs2586488 and rs2249492) and three COL18A1 SNPs (rs1050351, rs56335679, and rs55690336), and POP.

CONCLUSION

We are the first to evaluate the relationship between COL14A1, COL5A1, and COL4A2 polymorphisms and POP, besides COL3A1, COL1A1, and COL18A1, which have been reported previously. We found several candidate SNPs that were significantly associated with prolapse in Chinese women. Our results provide new evidence for further investigation of the involvement of these potential genes in the etiology of POP.

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.

Genetic association in female stress urinary incontinence based on proteomic findings: a case-control study

Introduction and hypothesis

Previous studies have indicated a hereditary component of stress urinary incontinence; however, evidence on candidate genes or single-nucleotide polymorphisms (SNPs) is scarce. We hypothesize a genetic association of female stress urinary incontinence based on significant differences of the urinary and serum proteomic pattern in the identical study population.

Methods

Case-control study of 19 patients and 19 controls. We searched for known SNPs of SUI candidate genes (COL1A1, MMP1, SERPINA5, UMOD) in the database of short genetic variations and PubMed. Genomic DNA was isolated using QIAamp DNA Blood Midi Kit (Qiagen). We performed Sanger sequencing of selected exons and introns.

Results

The rs885786 SNP of the SERPINA5 gene was identified in 15 cases and 10 controls (p = 0.09). The rs6113 SNP of the SERPINA5 gene was present in 4 controls compared to 0 cases (p = 0.105). The rs4293393, rs13333226 and rs13335818 SNPs of the UMOD gene were identified in five cases and two controls (p = 0.20), the rs1800012 SNP of the COL1A1 gene in five cases versus four controls (p = 0.24) and the homozygous rs1799750 SNP of the MMP1 gene in eight cases versus five controls (p = 0.18). The combination of the rs885786 SNP of the SERPINA5 gene and rs179970 SNP of the MMP1 gene was detected in ten cases versus five controls (p = 0.072).

Conclusions

We found nonsignificant trends toward associations of SNPs on the SERPINA5, UMOD and MMP1 gene and SUI.

Electronic supplementary material

The online version of this article (10.1007/s00192-019-03878-0) contains supplementary material, which is available to authorized users.

Association between col1a2 Polymorphism and the Occurrence of Pelvic Organ Prolapse in Brazilian Women

OBJECTIVE

 To evaluate the rs42524 polymorphism of the procollagen type I alpha (α) 2 (COL1A2) gene as a factor related to the development of pelvic organ prolapse (POP) in Brazilian women.

METHODS

 The present study involved 112 women with POP stages III and IV (case group) and 180 women with POP stages zero and I (control group). Other clinical data were obtained by interviewing the patients about their medical history, and blood was also collected from the volunteers for the extraction of genomic DNA. The promoter region of the COL1A2 gene containing the rs42524 polymorphism was amplified, and the discrimination between the G and C variants was performed by digestion of the polymerase chain reaction (PCR) products with the MspA1I enzyme followed by agarose gel electrophoresis analysis.

RESULTS

 A total of 292 women were analyzed. In the case group, 71 had the G/G genotype, 33 had the G/C genotype, and 7 had the C/C genotype. In turn, the ratio in the control group was 117 G/G, 51 G/C, and 11 C/C. There were no significant differences between the groups.

CONCLUSION

 Our data did not show an association between the COL1A2 polymorphism and the occurrence of POP.

Hypoxia-Inducible Factor 1-α (HIF-1α) Induces Apoptosis of Human Uterosacral Ligament Fibroblasts Through the Death Receptor and Mitochondrial Pathways

Background

Hypoxia induces cell apoptosis in the uterosacral ligaments of patients with pelvic organ prolapse by upregulation of hypoxia-inducible factor-1α (HIF-1α). This study aimed to investigate the effects of HIF-1α on human uterosacral ligament fibroblasts (hUSLFs) following treatment with the chemical inducer of hypoxia, cobalt chloride (CoCl₂), and to explore the underlying mechanisms.

Material/Methods

Ten women who underwent hysterectomy for benign disease provided uterosacral ligament tissue for cell extraction. Following CoCl₂ treatment, cell viability of isolated and cultured hUSLFs was evaluated by the MTT assay. JC-1 fluorescence mitochondrial imaging was used to study the change in mitochondrial membrane potential. Cell apoptosis and expression of apoptosis-associated proteins and collagen type I alpha 1 (COL1A1) were measured by flow cytometry, TUNEL and Western blot, respectively.

Results

Hypoxia increased the expression of HIF-1α and increased cell apoptosis, decreased cell viability and expression levels of COL1A1. The JC-1 assay showed that the mitochondrial membrane potential was reduced and caspase-8, and -9 inhibitors partly reduced hUSLF apoptosis. HIF-1α treatment downregulated the expression of cellular FLICE inhibitory protein (c-FLIP), decoy receptor 2 (DcR2), and the ratio of Bcl-2 to Bax, and upregulated the expression tumor necrosis factor related apoptosis-inducing ligand (TRAIL), death receptor 5 (DR5) or TRAIL-R2, Fas, Bcl-2 interacting protein 3 (BNIP3), and cytochrome C, and increased the activation of caspase-3, caspase-8, and caspase-9, all of which were reversed by knockdown of HIF-1α.

Conclusions

HIF-1α significantly induced apoptosis of hUSLFs through both the cell death receptor and the mitochondrial-associated apoptosis pathways.

The role of ADAMTS-2, collagen type-1, TIMP-3 and papilin levels of uterosacral and cardinal ligaments in the etiopathogenesis of pelvic organ prolapse among women without stress urinary incontinence

OBJECTIVE(S)

To investigate the potential role of 'a disintegrin-like and metalloproteinase with thrombospondin type motifs-2 (ADAMTS-2), collagen type-1, tissue inhibitor of metalloproteinases-3 (TIMP-3) and papilin' levels in the uterosacral ligament (USL) and cardinal ligament (CL) of the uterus on the etiopathogenesis of pelvic organ prolapse (POP) among postmenopausal women without stress urinary incontinence (SUI).

STUDY DESIGN

A total of 45 postmenopausal women, 22 diagnosed as POP stage III-IV and 23 age- and body mass index (BMI)-matched controls referred for hysterectomy due to POP or benign gynecological disease, respectively, were recruited prospectively for our study. The biopsies of the USL and CL were obtained during hysterectomy. ADAMTS-2, collagen type-1, TIMP-3 and papilin levels were determined by enzyme-linked immunosorbent assay (ELISA) method after tissue homogenization. We excluded patients who smoked or presented with SUI.

RESULTS

There were no differences in terms of demographic features including age, BMI, obesity, duration of menopause, gravidity, parity, delivery modes and family history for POP between the POP and non-POP groups. Significant differences in the levels of ADAMTS-2, collagen type-1, TIMP-3 and papilin of USL were noted among the groups. Females with POP had lower levels of ADAMTS-2, collagen type-1, TIMP-3 and papilin in the USL compared to non-POP females. All investigated markers in the CL were also decreased in the POP group, but this relationship was not statistically significant. When age, duration of menopause, gravidity, parity and obesity were taken as covariates, only the USL papilin levels were negatively predictive for the development of POP.

CONCLUSION(S)

ADAMTS-2, collagen type-1, TIMP-3 and papilin levels of the USL play essential roles in the etiopathogenesis of POP among postmenopausal women without SUI. Moreover, significantly decreased USL papilin levels in females with POP suggest the importance of the USL and the impact of papilin on the development of POP.

Identification of key genes and pathways in pelvic organ prolapse based on gene expression profiling by bioinformatics analysis

PURPOSE

The aim of this study was to elucidate the molecular mechanisms and to identify the key genes and pathways for pelvic organ prolapse (POP) using bioinformatics analysis.

METHODS

The microarray data for GSE53868 included 12 POP and 12 non-POP anterior vaginal wall samples. Differentially expressed genes (DEGs) were identified by GEO2R online tool. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID database, and a DEG-associated protein-protein interaction (PPI) network was constructed using STRING and visualized in Cytoscape. MCODE was used for module analysis of the PPI network.

RESULTS

A total of 257 upregulated and 333 downregulated genes were identified. GO and KEGG pathway enrichment analyses showed that the upregulated DEGs were strongly associated with immune response, complement activation, classical pathway, phagocytosis, and recognition; the downregulated genes were mainly associated with cellular response to zinc ion, negative regulation of growth, and apoptotic process. Based on the PPI network, IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A were screened as hub genes. The four most significant sub-modules of DEGs were extracted after network module analysis. These genes were mainly associated with the negative regulation of growth and inflammatory response. The KEGG pathway enrichment analysis revealed that these genes were associated with Mineral absorption, Jak-STAT signaling pathway, cytokine-cytokine receptor interaction, and chemokine signaling pathway.

CONCLUSIONS

These microarray data and bioinformatics analyses provide a useful method for the identification of key genes and pathways associated with POP. Moreover, some crucial DEGs, such as IL6, MYC, CCL2, ICAM1, PTGS2, SERPINE1, ATF3, CDKN1A, and CDKN2A, potentially play an important role in the development and progression of POP.

Obesity and pelvic organ prolapse: a systematic review and meta-analysis of observational studies

BACKGROUND

Studies evaluating the association between obesity and pelvic organ prolapse report estimates that range from negative to positive associations. Heterogeneous definitions for pelvic organ prolapse and variable choices for categorizing obesity measures have made it challenging to conduct meta-analysis.

OBJECTIVE

We systematically evaluated evidence to provide quantitative summaries of association between degrees of obesity and pelvic organ prolapse, and identify sources of heterogeneity.

STUDY DESIGN

We searched for all indexed publications relevant to pelvic organ prolapse up until June 18, 2015, in PubMed/MEDLINE to identify analytical observational studies published in English that reported risk ratios (relative risk, odds ratio, or hazard ratio) for body mass index categories in relation to pelvic organ prolapse. Random effects meta-analyses were conducted to report associations with pelvic organ prolapse for overweight and obese body mass index categories compared with women in the normal-weight category (referent: body mass index <25 kg/m²).

RESULTS

Of the 70 studies that reported evidence on obesity and pelvic organ prolapse, 22 eligible studies provided effect estimates for meta-analysis of the overweight and obese body mass index categories. Compared with the referent category, women in the overweight and obese categories had meta-analysis risk ratios of at least 1.36 (95% confidence interval, 1.20-1.53) and at least 1.47 (95% confidence interval, 1.35-1.59), respectively. Subgroup analyses showed effect estimates for objectively measured clinically significant pelvic organ prolapse were higher than for self-reported pelvic organ prolapse. Other potential sources of heterogeneity included proportion of postmenopausal women in study and reported study design.

CONCLUSION

Overweight and obese women are more likely to have pelvic organ prolapse compared with women with body mass index in the normal range. The finding that the associations for obesity measures were strongest for objectively measured, clinically significant pelvic organ prolapse further strengthens this evidence. However, prospective investigations evaluating obesity and pelvic organ prolapse are few.

Matrix Metalloproteinase-1 Expression in Women With and Without Pelvic Organ Prolapse: A Systematic Review and Meta-analysis

This meta‐analysis was conducted to estimate the association between matrix metalloproteinase‐1 (MMP‐1) expression and pelvic organ prolapse (POP) in women. Relevant studies published before 6 December 2015 were identified by searching PubMed, Ovid, EBSCO, and EMBASE. A total number of five case–control studies, including 182 POP cases and 192 controls, were identified. The results indicated that women without POP had a lower MMP‐1 level of expression compared with women with POP (odds ratio = 0.54, 95% confidence interval: 0.43–0.67, P = 0.000). After stratification by biopsy site, ethnicity, or menopausal status, this finding was also confirmed in the subgroup analysis with no significant changes. Egger's linear regression test revealed a potential publication bias (P = 0.028). The findings of our study indicate that women who suffer from POP have a higher expression level of MMP‐1 than women without POP.

Matrix metalloproteinase-3 gene promoter polymorphisms: A potential risk factor for pelvic organ prolapse

Pelvic organ prolapse (POP) is a common multifactorial condition. Matrix metalloproteinases (MMPs) are enzymes capable of breaking down various connective tissue elements. Single-nucleotide polymorphisms (SNPs) in regulatory areas of MMP-encoding genes can alter their transcription rate, and therefore the possible effect on pelvic floor supporting structures. The insertion of an adenine (A) base in the promoter of the MMP-3 gene at position -1612/-1617 produces a sequence of six adenines (6A), whereas the other allele has five (5A). The aim of the present study was to investigate the possible association of MMP-3 gene promoter SNPs with the risk of POP. The patient group comprised 80 women with clinically significant POP [Stage II, III or IV; POP quantification (POP-Q) system]. The control group consisted of 80 females without any or important pelvic floor support defects (Stages 0 or I; POP-Q system). All the participants underwent the same preoperative evaluation. SNP detection was determined with whole blood sample DNA analysis by quantitative polymerase chain reaction (PCR) in LightCycler^® PCR platforms, using the technique of sequence-specific hybridization probe-binding assays and melting temperature curve analysis. The results showed there was no statistically significant difference between 5A/5A, 5A/6A and 6A/6A MMP-3 gene promoter variants in the two study groups (P=0.4758). Therefore, MMP-3 gene promoter SNPs alone is insufficient to increase the genetic susceptibility to POP development.

Pathophysiological aspects of cystocele with a 3D finite elements model

PURPOSES

The objective of this study is to design a 3D biomechanical model of the female pelvic system to assess pelvic organ suspension theories and understand cystocele mechanisms.

METHODS

A finite elements (FE) model was constructed to calculate the impact of suspension structure geometry on cystocele. The sample was a geometric model of a control patient's pelvic organs. The method used geometric reconstruction, implemented by the biomechanical properties of each anatomic structure. Various geometric configurations were simulated on the FE method to analyse the role of each structure and compare the two main anatomic theories.

RESULTS

The main outcome measure was a 3D biomechanical model of the female pelvic system. The various configurations of bladder displacement simulated mechanisms underlying medial, lateral and apical cystocele. FE simulation revealed that pubocervical fascia is the most influential structure in the onset of median cystocele (essentially after 40 % impairment). Lateral cystocele showed a stronger influence of arcus tendineus fasciae pelvis (ATFP) on vaginal wall displacement under short ATFP lengthening. In apical cystocele, the uterosacral ligament showed greater influence than the cardinal ligament. Suspension system elongation increased displacement by 25 % in each type of cystocele.

CONCLUSIONS

A 3D digital model enabled simulations of anatomic structures underlying cystocele to better understand cystocele pathophysiology. The model could be used to predict cystocele surgery results and personalising technique by preoperative simulation.

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.

Association of matrix metalloproteinase-10 polymorphisms with susceptibility to pelvic organ prolapse

AIM

The aim of this study was to explore the correlation between genetic mutations in matrix metalloproteinase-10 (MMP-10) and susceptibility to pelvic organ prolapse (POP).

MATERIAL AND METHODS

From September 2011 to December 2013, 263 subjects were recruited, including 91 patients with POP (case group) and 172 non-POP patients (control group). Total MMP-10 concentrations in serum were measured by enzyme-linked immunosorbent assay. The genotyping of MMP-10 was achieved by quantitative real-time polymerase chain reaction. All data were analyzed with SPSS 18.0.

RESULTS

We found that parity, menopause, history of total hysterectomy, and family history of POP were all significantly higher in the POP group than in the control group (P = 0.017, P = 0.046, P = 0.0029 and P < 0.001, respectively). Serum MMP-10 levels were obviously higher in the POP group than in the control group (P < 0.05). In addition, there was a statistically significant difference between the two groups in the distribution frequency of the MMP-10 (rs17435959G/C) genotype (P < 0.05). However, the distribution frequency of the MMP-10 (rs17293607C/T) genotype between the two groups showed no significant differences (P > 0.05). Furthermore, the patients with parity > 2 and postmenopausal women had elevated serum MMP-10 levels, and the patients with parity > 2 and postmenopausal women who carried the G/C + C/C genotype in the MMP-10 gene had an increased risk of POP.

CONCLUSION

We support the view that the rs17435959 polymorphism of the MMP-10 gene may be associated with an increased risk of POP.

Verification of the Chromosome Region 9q21 Association with Pelvic Organ Prolapse Using RegulomeDB Annotations

Pelvic organ prolapse (POP) is a common highly disabling disorder with a large hereditary component. It is characterized by a loss of pelvic floor support that leads to the herniation of the uterus in or outside the vagina. Genome-wide linkage studies have shown an evidence of POP association with the region 9q21 and six other loci in European pedigrees. The aim of our study was to test the above associations in a case-control study in Russian population. Twelve SNPs including SNPs cited in the above studies and those selected using the RegulomeDB annotations for the region 9q21 were genotyped in 210 patients with POP (stages III-IV) and 292 controls with no even minimal POP. Genotyping was performed using the polymerase chain reaction with confronting two-pair primers (PCR–CTPP). Association analyses were conducted for individual SNPs, 9q21 haplotypes, and SNP-SNP interactions. SNP rs12237222 with the highest RegulomeDB score 1a appeared to be the key SNP in haplotypes associated with POP. Other RegulomeDB Category 1 SNPs, rs12551710 and rs2236479 (scores 1d and 1f, resp.), exhibited epistatic effects. In this study, we verified the region 9q21 association with POP in Russians, using RegulomeDB annotations.

Exome sequencing identifies a novel gene, WNK1, for susceptibility to pelvic organ prolapse (POP)

Pelvic organ prolapse (POP) is a common gynecological disorder; however, the genetic components remain largely unidentified. Exome sequencing has been widely used to identify pathogenic gene mutations of several diseases because of its high chromosomal coverage and accuracy. In this study, we performed whole exome sequencing (WES), for the first time, on 8 peripheral blood DNA samples from representative POP cases. After filtering the sequencing data from the dbSNP database (build 138) and the 1000 Genomes Project, 2 missense variants in WNK1, c.2668G > A (p.G890R) and c.6761C> T (p.P2254L), were identified and further validated via Sanger sequencing. In validation stage, the c.2668G > A (p.G890R) variant and 8 additional variants were detected in 11 out of 161 POP patients. All these variants were absent in 231 healthy controls. Functional experiments showed that fibroblasts from the utero-sacral ligaments of POP with WNK1 mutations exhibited loose and irregular alignment compared with fibroblasts from healthy controls. In sum, our study identified a novel gene, WNK1, for POP susceptibility, expanded the causal mutation spectrums of POP, and provided evidence for the genetic diagnosis and medical management of POP in the future.

Systematic review and metaanalysis of genetic association studies of urinary symptoms and prolapse in women

OBJECTIVE

Family studies and twin studies demonstrate that lower urinary tract symptoms and pelvic organ prolapse are heritable. This review aimed to identify genetic polymorphisms tested for an association with lower urinary tract symptoms or prolapse, and to assess the strength, consistency, and risk of bias among reported associations.

STUDY DESIGN

PubMed and HuGE Navigator were searched up to May 1, 2014, using a combination of genetic and phenotype key words, including "nocturia," "incontinence," "overactive bladder," "prolapse," and "enuresis." Major genetics, urology, and gynecology conference abstracts were searched from 2005 through 2013. We screened 889 abstracts, and retrieved 78 full texts. In all, 27 published and 7 unpublished studies provided data on polymorphisms in or near 32 different genes. Fixed and random effects metaanalyses were conducted using codominant models of inheritance. We assessed the credibility of pooled associations using the interim Venice criteria.

RESULTS

In pooled analysis, the rs4994 polymorphism of the ADRB3 gene was associated with overactive bladder (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.7-3.6; n = 419). The rs1800012 polymorphism of the COL1A1 gene was associated with prolapse (OR, 1.3; 95% CI, 1.0-1.7; n = 838) and stress urinary incontinence (OR, 2.1; 95% CI, 1.4-3.2; n = 190). Other metaanalyses, including those for polymorphisms of COL3A1,LAMC1,MMP1,MMP3, and MMP9 did not show significant effects. Many studies were at high risk of bias from genotyping error or population stratification.

CONCLUSION

These metaanalyses provide moderate epidemiological credibility for associations of variation in ADRB3 with overactive bladder, and variation of COL1A1 with prolapse. Clinical testing for any of these polymorphisms cannot be recommended based on current evidence.

Genetic epidemiology of pelvic organ prolapse: a systematic review

Given current evidence supporting a genetic predisposition for pelvic organ prolapse, we conducted a systematic review of published literature on the genetic epidemiology of pelvic organ prolapse. Inclusion criteria were linkage studies, candidate gene association and genome-wide association studies in adult women published in English and indexed in PubMed through Dec. 2012, with no limit on date of publication. Methodology adhered to the PRISMA guidelines. Data were systematically extracted by 2 reviewers and graded by the Venice criteria for studies of genetic associations. A metaanalysis was performed on all single nucleotide polymorphisms evaluated by 2 or more studies with similar methodology. The metaanalysis suggests that collagen type 3 alpha 1 (COL3A1) rs1800255 genotype AA is associated with pelvic organ prolapse (odds ratio, 4.79; 95% confidence interval, 1.91-11.98; P = .001) compared with the reference genotype GG in populations of Asian and Dutch women. There was little evidence of heterogeneity for rs1800255 (P value for heterogeneity = .94; proportion of variance because of heterogeneity, I(2) = 0.00%). There was insufficient evidence to determine whether other single nucleotide polymorphisms evaluated by 2 or more papers were associated with pelvic organ prolapse. An association with pelvic organ prolapse was seen in individual studies for estrogen receptor alpha (ER-α) rs2228480 GA, COL3A1 exon 31, chromosome 9q21 (heterogeneity logarithm of the odds score 3.41) as well as 6 single nucleotide polymorphisms identified by a genome-wide association study. Overall, individual studies were of small sample size and often of poor quality. Future studies would benefit from more rigorous study design as outlined in the Venice recommendations.

UVA-photoactivated riboflavin effect on isolated vaginal tissues derived from pelvic organ prolapse cases

PURPOSE

To determine the optimal riboflavin exposure time before UVA irradiation and to study the effects of exogenous collagen on the mechano-tensile stiffness of isolated vaginal tissue strips after riboflavin UVA photoactivation.

METHODS

Vaginal tissue strips from pelvic organ prolapse (POP) cases were soaked in 0.1% riboflavin (0, 10, 20, 30 min), exposed to UVA photoactivation, and tensile stiffness was measured with a tensiometer. Collagen solution was injected (0.2 mL) into each strip, exposed to riboflavin with or without UVA photoactivation, and tensile stiffness was measured (n=6).

RESULTS

Vaginal tissues treated with riboflavin for 10, 20 or 30 min followed by UVA irradiation displayed 21.2, 32.4 and 33.9% stronger tensile stiffness, respectively. Exogenous collagen administered before riboflavin UVA photoactivation resulted in 20% improvement in tensile stiffness. The tensile stiffness of vaginal tissues injected with collagen without the riboflavin UVA treatment was similar to control tissues.

CONCLUSION

The results demonstrated increased tensile stiffness in isolated POP-derived vaginal tissues after riboflavin UVA photoactivation suggesting improved mechanical properties from collagen cross-linking. Administering exogenous collagen before riboflavin UVA treatment also improved tensile stiffness. More studies are needed to corroborate the present minimally invasive approach for strengthening vaginal tissues.

Licochalcone A inhibits the migration and invasion of human lung cancer cells via inactivation of the Akt signaling pathway with downregulation of MMP-1/-3 expression

Licochalcone A (LicA), a major phenolic constituent of Glycyrrhiza inflata, has been reported to exhibit anti-tumor, anti-inflammatory, and anti-metastatic properties in various cancer cells and animal models. The aim of this study was to determine the anti-tumor effects of LicA on lung cancer cells. The results indicated that LicA exhibited effective inhibition of cell migration and invasion of A549 and H460 cells under non-cytotoxic concentrations. Furthermore, LicA was also found to significantly inhibit the proteins and messenger RNA (mRNA) expression of MMP-1 and MMP-3 in A549 cells. Moreover, treatment of A549 cells with LicA-inhibited activation of the phosphorylation of Akt and inhibition of Akt by LY294002 (PI3K inhibitor) or transfection with the constitutive active-Akt (CA-Akt) expression vector significantly abolished the LicA-inhibited migration and invasion through activation of the Akt pathway. Further mechanistic studies revealed that LicA inhibits Akt signaling pathways and downstream transcription factors Sp1 expression. These findings imply a critical role for Akt inhibition in the LicA-inhibited migration and invasion of lung cancer cells. Thus, LicA might be used as an anti-invasive agent in the treatment of lung cancer.

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.

Association between pelvic organ prolapse and stress urinary incontinence with collagen

The aim of the present study was to investigate the ultrastructure and content of collagen in uterosacral ligaments and paraurethral tissues in patients with pelvic organ prolapse (POP) and stress urinary incontinence (SUI), analyzing the association between POP and collagen dysfunction. The study comprised three groups: Control, POP and POP with SUI (n=30 per group). Histological characteristics of collagen fiber were observed and the diameters were measured using light and electron microscopy to determine the Type I and Type III collagen content of the main ligament in the urethral specimens. In the POP and POP with SUI groups, observations included diffuse atrophy of smooth muscles, active fibroblast metabolism, swollen mitochondria and visible Golgi apparatus. The collagen fibril diameters in the cardinal ligaments, uterosacral ligaments and paraurethral tissues were significantly greater in the POP and POP with SUI groups compared with those in the control group (P<0.01). In addition, the expression levels of Type I and Type III collagen were significantly lower in the POP and POP with SUI groups when compared with the control group (P<0.01). In the POP with SUI group, pelvic tissues were frail, resulting in smooth muscle bundles comminuting and arranging in a disorganized pattern. Fibroblast and myoblast metabolisms were active and new microvascular cells were weak. However, the collagen fibril diameter increased. Thus, collagen and ultrastructural changes in the pelvic floor may be associated with the development of POP and SUI.

Association of collagen type I alpha 1 gene polymorphism with inguinal hernia

PURPOSE

A positive family history is an important risk factor for inguinal hernia development, suggesting a genetic trait for hernia disease. However, gene mutations responsible for abdominal wall hernia formation in humans have not yet been studied. We aimed to evaluate whether the functional Sp1 binding site polymorphism within intron 1 of the collagen type I, alpha 1 (COL1A1) gene was associated specifically with inguinal hernia disease.

METHODS

85 participants with surgically diagnosed inguinal hernia disease, and 82 physically active controls without any history of connective tissue disease and hernia were recruited for this case-control genetic association study. Polymerase chain reaction and restriction fragment length polymorphism and agarose gel electrophoresis techniques were used to detect these polymorphisms.

RESULTS

Significantly, more patients gave a positive family history for an inguinal hernia compared to healthy controls (OR 3.646, 95 % CI 1.375-9.670, P = 0.006). COL1A1 Sp1 SNP (rs 1800012) was identified. Results demostrated statistically significant deviation from HWE for cases (P = 0.007), but not for the controls (P = 0.276). Our results revealed an increased frequency of COL1A1 Sp1 Ss genotype in inguinal hernia patients (OR 3.593, 95 % CI 1.867-6.915, P = 0.000).

CONCLUSIONS

This results suggest that polymorphism of the COL1A1 Sp1 binding site is associated with an increased risk for developing inguinal hernias. So, rs 1800012 locus is a potential candidate region for susceptibility in molecular mechanism of inguinal hernia pathophysiology.

The polymorphisms of the MMP-1 and the MMP-3 genes and the risk of pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

To investigate the associations between single nucleotide polymorphism (SNP) type 1G/2G at position -1607/-1608 of the matrix metalloproteinase (MMP)-1 gene and SNP type 5A/6A at position -1612/-1617 of the MMP-3 gene and the development of pelvic organ prolapse (POP) in women.

METHODS

133 patients with symptomatic POP were included in the study group. The control group consisted of 132 women with a normal pelvic floor. 1G/2G MMP-1 and 5A/6A MMP-3 SNPs were determined by polymerase chain reaction (PCR) and restriction fragments length polymorphism analysis.

RESULTS

When estimated individually none of the investigated SNPs were associated with POP. The combined MMP-1/MMP-3 SNP analysis showed that the following polymorphic pairs were overrepresented in women with POP: 1G/2G -5A/6A, 2G/2G -5A/6A, 2G/2G -5A/5A, 1G/1G -6A/6A, p=0.005.

CONCLUSIONS

The combined effect of -1607/-1608 MMP-1 and -1612/-1617 MMP-3 SNPs may contribute to the development of POP in some women.