The rs2018736 fibulin-5 polymorphism as a determinant for pelvic organ prolapse: a case-control study.

OBJECTIVE: Fibulin-5 is a connective tissue component and may play a role in pelvic organ prolapse (POP) pathogenesis. This study aimed to verify the association of the rs2018736 polymorphism of the fibulin-5 gene with POP in postmenopausal Brazilian women, and to determine the risk factors for POP. METHOD: This observational, cross-sectional, case-control study assessed postmenopausal women with advanced POP (stages III and IV) and control women (stages 0 and I) by examination and peripheral blood sample collection. DNA sequences were analyzed by real-time reverse-transcriptase polymerase chain reaction. A logistic regression model was used with p < 0.05 for significance. RESULTS: A total of 565 participants were evaluated (325 POP and 240 control). The homozygous C allele of rs2018736 (CC) was protective against POP (odds ratio [OR] 0.49, 95% confidence interval [CI] 0.26-0.91). Age (OR 1.09, 95% CI 1.05-1.13), number of pregnancies (OR 1.14, 95% CI 1.01-1.28), vaginal delivery (OR 5.32, 95% CI 2.58-11.01), forceps delivery (OR 3.34, 95% CI 1.72-6.47), weight of newborn (OR 1.0007, 95% CI 1.0002-1.0011), family history of POP (OR 2.35, 95% CI 1.24-4.44), hypertension (OR 1.74, 95% CI 1.01-3.00) and diabetes (OR 2.19, 95% CI 1.07-4.48)] were independent predictors for POP; cesarean (OR 0.02, 95% CI 0.005-0.09) was protective. CONCLUSION: The rs2018736-CC genotype of the fibulin-5 gene has a protective role against POP.

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.

Molecular mechanisms of pelvic organ prolapse influenced by FBLN5 via FOSL1/miR-222/MEIS1/COL3A1 axis.

This study delves into the role of FBLN5 in pelvic organ prolapse (POP) and its molecular mechanisms, focusing on the FOSL1/miR-222/MEIS1/COL3A1 axis. Gene relationships linked to POP were confirmed using bioinformatics databases like GEO and StarBase. Primary human uterosacral ligament fibroblasts (hUSLF) were extracted and subjected to mechanical stretching. Cellular cytoskeletal changes were examined via phalloidin staining, intracellular ROS levels with a ROS kit, cell apoptosis through flow cytometry, and cell senescence using ß-galactosidase staining. FBLN5's downstream targets were identified, and the interaction between FOSL1 and miR-222 and miR-222 and MEIS1 were validated using assays. In rat models, the role of FBLN5 in POP was assessed using bladder pressure tests. Results indicated diminished FBLN5 expression in uterine prolapse. Enhanced FBLN5 countered mechanical damage in hUSLF cells by downregulating FOSL1. FOSL1 augmented miR-222, inhibiting MEIS1, which subsequently fostered COL3A1 transcription. In rat models, the absence of FBLN5 exacerbated POP by influencing the FOSL1/miR-222/MEIS1/COL3A1 pathway. FBLN5's protective role likely involves regulating the above axis and boosting COL3A1 expression. Further research is needed to validate the effectiveness and safety of this mechanism in human patients and to propose potential new treatment options.

Estrogen and Androgen Receptor Status in Uterosacral Ligaments of Women with Pelvic Organ Prolapse Stratified by the Pelvic Organ Prolapse Histology Quantification System.

Menopause is a significant risk factor for pelvic organ prolapse (POP), suggesting that ovarian sex steroids play a major role in the etiology of the condition. POP results from failure of the uterine-cervix-vagina support structures, including the uterosacral ligament (USL). We previously identified consistent degenerative USL phenotypes that occur in POP and used their characteristics to develop a standardized POP Histologic Quantification System (POP-HQ). In this study, POP and matched control USL tissue was first segregated into the unique POP-HQ phenotypes, and specimens were then compared for estrogen receptor (ER) alpha (ERα), ERbeta (ERß), the G-protein estrogen receptor (GPER), and androgen receptor (AR) content via immunohistochemical staining. ER and AR expression levels in the control USL tissues were indistinguishable from those observed in the POP-A phenotype, and partially overlapped with those of the POP-I phenotype. However, control-USL steroid receptor expression was statistically distinct from the POP-V phenotype. This difference was driven mainly by the increased expression of GPER and AR in smooth muscle, connective tissue, and endothelial cells, and increased expression of ERα in connective tissue. These findings support a multifactorial etiology for POP involving steroid signaling that contributes to altered smooth muscle, vasculature, and connective tissue content in the USL. Furthermore, these data support the concept that there are consistent and distinct degenerative processes that lead to POP and suggest that personalized approaches are needed that target specific cell and tissues in the pelvic floor to treat or prevent this complex condition.

Lifestyle factors, metabolic factors and socioeconomic status for pelvic organ prolapse: a Mendelian randomization study.

BACKGROUND: Previous observational studies have reported that lifestyle factors, metabolic factors and socioeconomic status are associated with the development of female pelvic organ prolapse (POP); however, whether these associations are causal remains unclear. The current study aimed to assess the causal effect of lifestyle factors, metabolic factors and socioeconomic status on POP risk. METHODS: We conducted a two-sample Mendelian randomization (MR) study based on summary-level data from the largest available genome-wide association studies (GWAS) to evaluate whether lifestyle factors, metabolic factors and socioeconomic status are causally related to POP. We used single nucleotide polymorphisms that are strongly associated with exposure at the genome-wide significance level (P < 5 × 10-8) as instrumental variables from genome-wide association studies. The method of random-effect inverse-variance weighting (IVW) was used as the primary analysis method, supplemented with the weighted median, MR-Egger and the MR pleiotropy residual sum and outlier applied to verify the MR assumptions. Two-step MR was conducted to investigate potential intermediate factors that are on the causal pathway from exposure to POP. RESULTS: There were associations with POP for genetically predicted waist-to-hip ratio (WHR) (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.03 per SD-increase, P < 0.001), WHR adjusted for body mass index (WHRadjBMI) (OR 1.017, 95% CI 1.01-1.025 per SD-increase, P < 0.001) and education attainment (OR 0.986, 95% CI 0.98-0.991 per SD-increase) in the meta-analysis. Additionally, genetically predicted coffee consumption (OR per 50% increase 0.67, 95% CI 0.47-0.96, P = 0.03), vigorous physical activity (OR 0.83, 95% CI 0.69-0.98, P = 0.043) and high-density lipoprotein cholesterol (HDL-C) (OR 0.91, 95% CI 0.84-0.98 per SD-increase, P = 0.049) were inversely associated with POP in the FinnGen Consortium. The mediation analysis showed that the indirect effects of education attainment on POP were partly mediated by WHR and WHRadjBMI, with a mediated proportion of 27% and 13% in the UK Biobank study, respectively. CONCLUSIONS: Our study provides MR evidence of a robust causal association of WHR, WHRadjBMI and education attainment with POP.

Bioinformatic analysis of biological changes involved in pelvic organ prolapse.

The molecular mechanisms involved in the pathogenesis of pelvic organ prolapse (POP) remain unclear. This study aimed to identify key molecules involved in the pathogenesis and progression of POP. Differentially expressed genes (DEGs) were identified based on gene expression data extracted from the GSE53868, GSE28660, and GSE12852 datasets in the gene expression omnibus database. The R software was used for data mining, and gene ontology functional annotation and Kyoto encyclopedia of genes and genomes enrichment analyses were performed to explore the biological functions of DEGs. A protein-protein interaction network (PPI) was constructed using the Search Tool for the Retrieval of Interacting Genes database, and hub genes were identified by the Cytoscape plug-in cytoHubba. In addition, the CIBERSORT algorithm was used to analyze and evaluate immune cell infiltration in POP tissues. A total of 92 upregulated DEGs were identified and subjected to enrichment analysis. Gene ontology analysis revealed that these DEGs were associated with response to hormones, positive regulation of cell death, collagen-containing extracellular matrix, and extracellular matrix. Kyoto encyclopedia of genes and genomes pathway analysis showed that the upregulated genes were mainly enriched in the phosphatidylinositol 3-kinase-AKT signaling pathway. The PPI network was structured. Nodes in the PPI network were associated with structural molecular activity and collagen-containing extracellular matrix. A total of 10 hub genes were identified, namely, CDKN1A, IL-6, PPARG, ADAMTS4, ADIPOQ, AREG, activating transcription factor 3, CCL2, CD36, and Cell death-inducing DNA fragmentation factor-like effector A. Furthermore, patients with POP were found to have a higher abundance of CD8-positive T cells in the 3 gene expression omnibus datasets. The abundance of CD8-positive T cells was negatively correlated with that of follicular helper T cells (Pearson correlation coefficient = -0.34, P < .01) or gamma delta T cells (Pearson correlation coefficient = -0.33, P < .01). But was positively correlated with that of M2 macrophages (Pearson correlation coefficient = 0.35, P < .01) and activated memory CD4 T cells (Pearson correlation coefficient = 0.34, P < .01). Altogether, PPARG, ADAMTS4, ADIPOQ, AREG, CD36, and Cell death-inducing DNA fragmentation factor-like effector A genes were discovered in the POP process for the first time, which should be intensively investigated.

Interactions between genetic variants and environmental risk factors are associated with the severity of pelvic organ prolapse.

OBJECTIVE: Both environmental and genetic risk factors contribute to pelvic organ prolapse (POP). No genome-wide study has investigated the gene-environment (G × E) interactions. In this study, we aim to identify single nucleotide polymorphisms (SNPs) that may interact with the potential environmental factors, maximum birth weight, and age in Chinese women. METHODS: We recruited 576 women for phase 1 and 264 women for phase 2 with stages III and IV prolapse from six geographic regions of China. Genomic DNAs from blood samples were genotyped using Affymetrix Axiom Genome-Wide CHB1 Array of 640,674 SNPs for phase 1 and Illumina Infinium Asian Screening Array of 743,722 SNPs for phase 2. Meta-analysis was used to combine the two results. Interactions of genetic variants with maximum birth weight and age on POP severity were identified. RESULTS: In phase 1, 502,283 SNPs in 523 women passed quality control and 450 women had complete POP-quantification measurements. In phase 2, 463,351 SNPs in 257 women passed quality control with complete POP-quantification measurements. Three SNPs rs76662748 ( WDR59 , Pmeta = 2.146 × 10 -8 ), rs149541061 ( 3p26.1 , Pmeta = 9.273 × 10 -9 ), and rs34503674 ( DOCK9 , Pmeta = 1.778 × 10 -9 ) respectively interacted with maximum birth weight, and two SNPs rs74065743 ( LINC01343 , Pmeta = 4.386 × 10 -8 ) and rs322376 ( NEURL1B - DUSP1 , Pmeta = 2.263 × 10 -8 ), respectively, interacted with age. The magnitude of disease severity associated with maximum birth weight and age differed according to genetic variants. CONCLUSIONS: This study provided preliminary evidence that interactions between genetic variants and environmental risk factors are associated with POP severity, suggesting the potential use of combining epidemiologic exposure data with selected genotyping for risk assessment and patient stratification.

Expression profile analysis of lncRNA and mRNA in uterosacral ligaments of women with pelvic organ prolapse by RNA-seq.

Pelvic organ prolapse (POP) is a conventional gynecological condition and the mechanism is not entirely clear. Although an increasing number of studies revealed that long non-coding RNAs (lncRNAs) have essential functions in many diseases, little knowledge has been acquired in POP. The current study aimed to investigate the regulatory mechanism of lncRNA in POP. In this report, we investigated the expression profile of lncRNAs and mRNAs between POP and the control groups in human uterosacral ligament (hUSL) tissues through RNA-seq. Cytoscape was used to construct a POP-specific lncRNA-mRNA network and select key molecules. This RNA-Seq analysis uncovered a total of 289 lncRNAs, and 41 lncRNAs and 808 mRNAs were differentially expressed between the POP and non-POP groups. Four lncRNAs were identified and validated by real-time PCR. The result of gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) indicated that differentially expressed lncRNAs were abundant in the biological processes and signaling pathways concerned in POP. The differentially expressed lncRNAs were mainly enriched in protein binding, the single-organism cellular process, and cytoplasmic part. The network was constructed based on the correlation analyses of the abnormally expressed lncRNAs and their target proteins to imitate their interactions. Taken together, this study was the first to demonstrate the differential expression profiles of lncRNA in POP and normal tissues by sequencing technology. Our study indicated that lncRNAs could correlate with the development of POP and may be as significant genes in the diagnosis and treatment of POP.

Molecular Landscape of Pelvic Organ Prolapse Provides Insights into Disease Etiology.

Pelvic organ prolapse (POP) represents a major health care burden in women, but its underlying pathophysiological mechanisms have not been elucidated. We first used a case-control design to perform an exome chip study in 526 women with POP and 960 control women to identify single nucleotide variants (SNVs) associated with the disease. We then integrated the functional interactions between the POP candidate proteins derived from the exome chip study and other POP candidate molecules into a molecular landscape. We found significant associations between POP and SNVs in 54 genes. The proteins encoded by 26 of these genes fit into the molecular landscape, together with 43 other POP candidate molecules. The POP landscape is located in and around epithelial cells and fibroblasts of the urogenital tract and harbors four interacting biological processes-epithelial-mesenchymal transition, immune response, modulation of the extracellular matrix, and fibroblast function-that are regulated by sex hormones and TGFB1. Our findings were corroborated by enrichment analyses of differential gene expression data from an independent POP cohort. Lastly, based on the landscape and using vaginal fibroblasts from women with POP, we predicted and showed that metformin alters gene expression in these fibroblasts in a beneficial direction. In conclusion, our integrated molecular landscape of POP provides insights into the biological processes underlying the disease and clues towards novel treatments.

scRNA-seq reveals aging-related immune cell types and regulators in vaginal wall from elderly women with pelvic organ prolapse.

Introduction: In the pathology of pelvic organ prolapse (POP), little is known about the contributing role of pelvic microenvironment. Also, the age-related differences in pelvic microenvironment of POP patients is always ignored. In the present study, we investigated the age-related differences in pelvic microenvironment between Young POP patients and Old POP patients, and the novel cell types and critical regulators which contributes to the age-related differences. Methods: Single-cell transcriptomic analyses were used to detect the changes in cell composition and gene expression from the pelvic microenvironment of control group (<60 years), Young POP group (<60 years) and Old POP group (>60 years). Then, immunohistochemistry and immunofluorescence were used to verify the novel cell types and critical regulators in the pelvic microenvironment. Furthermore, histopathological alteration and mechanical property alteration in POP with different ages were revealed by vaginal tissue histology and biomechanical testing. Results: The up-regulated biological process in Old women with POP is mainly related to chronic inflammation, while the up-regulated biological process in Young women with POP is mainly related to extracellular matrix metabolism. Meantime, CSF3+ endothelial cells and FOLR2+ macrophages were found to play a central role in inducing pelvic chronic inflammation. Furthermore, the collagen fiber and mechanical property of POP patients decreased with aging. Conclusions: Taken together, this work provides a valuable resource for deciphering the aging-related immune cell types and the critical regulators in pelvic microenvironment. With better understanding of normal and abnormal events in this pelvic microenvironment, we provided rationales of personalized medicine for POP patients with different ages.

Bioinformatically deciphering immune cell infiltration and signature genes in pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: The study is aimed at bioinformatically deciphering immune cell infiltration, signature genes, and their correlations in POP. METHODS: Three microarray datasets were included. Matrixes representing the uterosacral ligament were merged as a test matrix and the others representing vaginal tissues were merged as a validation matrix. The single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm was performed to evaluate immune cell infiltration. Correlations among differential immune cells were revealed by Spearman's rank correlation. Differentially expressed genes (DEGs) were screened by both "Batch correction" and "RobustRankAggreg" methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes were conducted for functional analysis. Hub genes were identified through cytoHubba of Cytoscape, and further validated by a validation matrix and clinical samples as signature genes. Correlations of differential immune cells with signature genes were analyzed by Spearman's rank correlation. RESULTS: Five differential immune cells (macrophages, monocytes, regulatory T cell [Treg], type 1 T cell [Th1], and natural killer T cells [NKT]) were identified and eight pairs of immune cells had significant correlations. Screened 230 DEGs were extracellular matrix (ECM) and immune related. Eleven hub genes were initially identified and five of them (LOX, IL-6, SDC1, ICAM1, and CD38) were validated as signature genes. Significant correlations of differential immune cells with signature genes were shown in twelve pairs, especially Th1-IL6, NKT-IL6, Th1-ICAM1, macrophage-IL6, and macrophage-LOX pairs. CONCLUSIONS: Pelvic organ prolapse could be considered immune related. Significantly infiltrated immune cells may contribute to the development of POP through close involvement with ECM- and immune-related signature genes.

Transcriptome and metabolome analyses reveal the interweaving of immune response and metabolic regulation in pelvic organ prolapse.

INTRODUCTION AND HYPOTHESIS: The pathogenesis of pelvic organ prolapse (POP) remains unknown. Herein, we aim to reveal the molecular profile of POP by transcriptomic and metabolomic analysis. METHODS: We selected 12 samples of uterosacral ligaments (USLs) from 6 POP patients and 6 controls for transcriptomic and metabolomic analyses. Differentially expressed genes (DEGs) were identified using the R package edgeR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using clusterProfiler, and a protein-protein interaction (PPI) network was constructed using STRING and visualized in Cytoscape. Metabolomic profiling was performed by a liquid chromatography-tandem mass spectrometry system. RESULTS: Transcriptomic analysis identified 487 DEGs between the POP and control groups. Functional enrichment analysis revealed that they were mostly related to immune response terms, including "adaptive immune response," "T cell differentiation," and "T cell activation." In addition, PTPRC, LCK, CD247, IL2RB, CD2, CXR5, JUN, CD3E, IL2RG, and PRF1 were the 10 nodes with the highest node degrees in the PPI network. Metabolomic profiling revealed 290 differentially expressed metabolites, which significantly enriched in "glycerophospholipid metabolism," "nicotinate and nicotinamide metabolism," "glycine, serine, and threonine metabolism," "arginine and proline metabolism," "pyrimidine metabolism," and "purine metabolism." Finally, integrated analysis revealed that the DEGs involved in these significantly enriched metabolic pathways included NT5C1A, GMPR, SDS, ALAS2, CARNS1, PYCR1, P4HA3, PGS1, and NMRK2. CONCLUSIONS: Our findings demonstrate that the immune response and metabolic regulatory pathways are intertwined in POP and might provide new therapeutic targets.

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.

Effect of Nrf2 on Phenotype Changes of Macrophages in the Anterior Vaginal Wall of Women With Pelvic Organ Prolapse.

OBJECTIVE: The aim of this study was to observe the effect of nuclear factor-erythroid 2-related factor 2 (Nrf2) on the phenotype changes of macrophages in the anterior vaginal wall of patients with pelvic organ prolapse (POP). METHODS: The tissues of the anterior vaginal wall of the control group (n = 30) and POP groups (n = 60) were collected during operation. The expressions of Nrf2, iNOS (representative factor of M1 macrophages), and CD206 (representative factor of M2 macrophages) were determined by immunohistochemical staining and Western blot. Morphological changes and collagen distribution of the anterior vaginal wall were observed by hematoxylin-eosin staining and Masson trichrome staining. RESULTS: Compared with the control group, the expression levels of Nrf2 and CD206 protein in the anterior vaginal wall tissues of the POP groups were significantly decreased ( P < 0.05), and were negatively proportional to the degree of prolapse ( P < 0.05). The expression of iNOS was significantly increased and was directly proportional to the degree of prolapse ( P < 0.05). Hematoxylin-eosin staining and Masson trichrome staining showed that the collagen fibers are more sparsely arranged and disordered in the POP group than the control. CONCLUSIONS: In patients with POP, the expression of antioxidant factor Nrf2 is reduced in the vaginal anterior wall tissues and the antioxidant capacity is weakened, leading to the blocked polarization of macrophages and the accumulation of a large number of M1 macrophages in the tissue, affecting the occurrence and development of POP.

Treatment of Pelvic Organ Prolapse by the Downregulation of the Expression of Mitofusin 2 in Uterosacral Ligament Tissue via Mesenchymal Stem Cells.

Background: The relationship between pelvic organ prolapse (POP), an aging-related disease, and the senescence-related protein mitofusin 2 (Mfn2) has rarely been studied. The aim of the present study was to explore the therapeutic effects of the downregulation of Mfn2 expression by stem cells on POP through animal experiments. Methods: First, a rat POP model was constructed by ovariectomy and traction. The rats in the non-pelvic organ prolapse (NPOP) and POP groups were divided into four groups for negative controls (N1−N4, N1: NPOP-normal saline; N2: NPOP-untransfected stem cells; N3: NPOP-short hairpin negative control (NPOP-sh-NC); N4: NPOP-short hairpin-Mfn2 (NPOP-sh-Mfn2)), and four groups for prolapse (P1−P4, P1: POP-normal saline; P2: POP-untransfected stem cells; P3: POP-sh-NC; P4: POP-sh-Mfn2), respectively. Stem cells were then cultured and isolated. The expression of Mfn2 was inhibited by lentivirus transfection, and the stem cells were injected into the uterosacral ligament of the rats in each group. The expression levels of Mfn2 and procollagen 1A1/1A2/3A1 in the uterosacral ligaments of the rats were observed at 0, 7, 14, and 21 days after injection. Results: Compared to the rats in the NPOP group, the POP rats had significant prolapse. The Mfn2 expression in the uterosacral ligaments of the POP rats was significantly increased (p < 0.05, all), and the expression of procollagen 1A1/1A2/3A1 was significantly decreased (p < 0.001, all). The POP rat model maintained the same trend after 21 days (without stem cell injection). At day 14, compared to the rats in the N1 group, the Mfn2 expression in the uterosacral ligament of the rats in the N4 group was significantly decreased (p < 0.05, all), and the expression of procollagens was significantly increased (p < 0.05, all). Similarly, compared to the rats in the P1 group, the Mfn2 expression in the uterosacral ligament of the rats in the P4 group was significantly decreased (p < 0.05, all), and the expression of procollagens was significantly increased (p < 0.05, all). Similarly, on day 21, the Mfn2 mRNA and protein expression in the uterosacral ligament of the POP and NPOP rats was significantly decreased (p < 0.05, all), and the expression of procollagens was significantly increased (p < 0.05, all) in the rats in the sh-Mfn2 group (N4, P4) compared to the rats in the saline group (N1, P1). Conclusions: The downregulation of Mfn2 expression by stem cells decreased the expression of Mfn2 and increased the expression of procollagen1A1/1A2/3A1 in the uterosacral ligament of the POP rats; this effect was significant 14−21 days after the injection. Thus, Mfn2 may be a new target for POP control.

The rs2165241 polymorphism of the Loxl1 gene in postmenopausal women with pelvic organ prolapse.

OBJECTIVE: This study aimed to verify the presence of polymorphism rs2165241 of the lysyl oxidase-like 1 (Loxl1) gene and its association with pelvic organ prolapse (POP) in Brazilian women and determine risk factors for POP development. METHODS: The study was previously approved by the local research and ethics board. Postmenopausal women were included and divided into POP (stages III and IV) and control (stages 0 and I) groups. Peripheral blood samples were collected, and the DNA sequence of interest was analyzed by real-time reverse-transcriptase polymerase chain reaction. We used logistic regression and considered a recessive model of inheritance for the analysis, with p < 0.05 for significance. RESULTS: A total of 836 women were assessed: 426 POP cases and 410 controls. The frequencies of CC, CT and TT genotypes were similar in both groups. Age (odds ratio [OR] = 1.1, 95% confidence interval [CI] = 1.07; 1.14), number of vaginal births (OR = 17.06, 95% CI = 5.94; 48.97), family history (OR = 2.87, 95% CI = 1.57; 5.22) and weight of largest newborn (OR = 1.001, 95% CI = 1.0003; 1.001) were independent risk factors for POP, while multiple cesarean sections (two or more) was protective (OR = 0.17, 95% CI = 0.07; 0.42). CONCLUSION: No association was detected between rs2165241 of the Loxl1 gene and POP.

International Urogynecological Consultation (IUC): pathophysiology of pelvic organ prolapse (POP).

INTRODUCTION AND HYPOTHESIS: This manuscript is the International Urogynecology Consultation (IUC) on pelvic organ prolapse (POP) chapter one, committee three, on the Pathophysiology of Pelvic Organ Prolapse assessing genetics, pregnancy, labor and delivery, age and menopause and animal models. MATERIALS AND METHODS: An international group of urogynecologists and basic scientists performed comprehensive literature searches using pre-specified terms in selected biomedical databases to summarize the current knowledge on the pathophysiology of the development of POP, exploring specifically factors including (1) genetics, (2) pregnancy, labor and delivery, (3) age and menopause and (4) non-genetic animal models. This manuscript represents the summary of three systematic reviews with meta-analyses and one narrative review, to which a basic scientific comment on the current understanding of pathophysiologic mechanisms was added. RESULTS: The original searches revealed over 15,000 manuscripts and abstracts which were screened, resulting in 202 manuscripts that were ultimately used. In the area of genetics the DNA polymorphisms rs2228480 at the ESR1 gene, rs12589592 at the FBLN5 gene, rs1036819 at the PGR gene and rs1800215 at the COL1A1 gene are significantly associated to POP. In the area of pregnancy, labor and delivery, the analysis confirmed a strong etiologic link between vaginal birth and symptoms of POP, with the first vaginal delivery (OR: 2.65; 95% CI: 1.81-3.88) and forceps delivery (OR: 2.51; 95% CI: 1.24-3.83) being the main determinants. Regarding age and menopause, only age was identified as a risk factor (OR : 1.102; 95% CI: 1.02-1.19) but current data do not identify postmenopausal status as being statistically associated with POP. In several animal models, there are measurable effects of pregnancy, delivery and iatrogenic menopause on the structure/function of vaginal support components, though not on the development of POP. CONCLUSIONS: Genetics, vaginal birth and age all have a strong etiologic link to the development of POP, to which other factors may add or protect against the risk.

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.

Structural, functional and molecular pathogenesis of pelvic organ prolapse in patient and Loxl1 deficient mice.

Pelvic organ prolapse is a worldwide health problem to elderly women. Understanding its pathogenesis and an ideal animal model are crucial to developing promising treatments. The present study aimed to investigate new clinical significance and detailed mechanism of pelvic organ prolapse by comparing the structural, functional and molecular dysfunctions of pelvic organ prolapse in patient and Loxl1 deficient mice. Our results showed that human vagina tissues from prolapsed site showed disarranged collagen and elastic fibers compared with the non-prolapse tissue. A gene ontology (GO) analysis of differentially expressed genes revealed molecular changes mainly related to inflammatory response and extracellular matrix (ECM) organization. While the mice lacking Loxl1 developed stable POP phenotype and disordered ECM structure in histology. Such Loxl1 knockout mice exhibited a significantly urinary dysfunction and decreased mechanical properties of the pelvic floor tissues, implying that POP in human condition might be induced by progressively decreased mechanics of pelvic tissues following ECM catabolism. Similarly, we not only identified significant up-regulated ECM catabolism processes and down-regulated ECM synthesis processes, but also characterized high level of inflammatory response in vagina tissue of the Loxl1 deficient mice. Thus, all these pathological changes in the POP mice model was consistent with those of the clinical elderly patients. These findings provide new insight into remodeling of POP by LOXL1 regulation and be of great importance to develop combination treatments of ECM metabolism and inflammation regulation strategy.