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

The relationship between pelvic floor functions and vaginal microbiota in 6–8 weeks postpartum women

The impairment of pelvic floor muscle functions and Lactobacillus-deficient vaginal microbiota is common in postpartum women. However, few studies have explored the correlation between pelvic floor muscle functions and vaginal microbiota. Given this research gap, our study aims to investigate any potential association between these two conditions of postpartum women (6–8 weeks after childbirth). A total of 230 women who required postpartum pelvic floor function examination at Peking University International Hospital from December 2021 to April 2022 were enrolled in this study. The collected questionnaire information included progestational weight, body mass index (BMI), weight gain during pregnancy, neonatal weight, delivery type, multiparity, postpartum time, and urinary incontinence (UI). A total of 187 samples of vaginal secretions were collected, and the vaginal microbiota was detected by 16S rRNA sequence analysis. Finally, 183 samples were analyzed in the trial. All individuals were divided into two groups according to the results of pelvic floor muscle assessment to explore the difference between the incidence of postpartum urinary incontinence and vaginal microbiota. We found that the prevalence of UI was higher in the group with weakened pelvic floor muscles. Vaginal delivery, overweight, age, neonatal weight, and weight gain during pregnancy were all risk factors for postpartum urinary incontinence. The vaginal microbiome was no longer Lactobacillus dominant of most postpartum women (91.8%), while the diversity of microbiota increased. The Lactobacillus-deficient community, commonly labeled as community state type (CST) IV, was sub-divided into four communities. The abundance of vaginal Lactobacillus decreased in the group with compromised pelvic muscle functions, while the species richness and diversity increased significantly. In conclusion, the decreased pelvic floor muscle functions of postpartum women 6–8 weeks after delivery may disrupt the balance of vaginal microbiota, and the restoration of pelvic floor functions may contribute to a healthy and balanced vaginal microbiota.

Diastasis recti abdominis and pelvic floor dysfunction in peri- and postmenopausal women: a cross-sectional study

Introduction: Diastasis recti abdominis (DRA) and pelvic floor dysfunction (PFD) occurs commonly with aging; however, little is known about what leads to these changes.Objective: We aimed to investigate and compare the presence or absence of DRA and PFD in peri- and postmenopausal women.Methods: This cross-sectional study involved 150 participants who answered questions on their sociodemographic and clinical profiles related to urinary and fecal incontinence and pelvic organ prolapse. Diastasis recti abdominis was diagnosed with a digital caliper.Results: Supra-umbilical diastasis occurred in 37.3% of cases, and 78.6% of participants with DRA had PFD. No significant differences existed between participants with and without DRA in terms of background and clinical variables. However, participants with DRA were 2.6 times more likely to have PFD than participants without DRA. Furthermore, the presence of DRA was significantly shown to be a risk factor for PFD on binary logistic regression analyses (p = .01, OR = 3.2).Conclusions: This cross-sectional study suggests that DRA is a predictive factor of PFD in women aged over 50 years.

Role of lysyl oxidase like 1 in regulation of postpartum connective tissue metabolism in the mouse vagina†

Pelvic organ prolapse (POP) in lysyl oxidase like-1 knockout (Loxl1 KO) mice occurs primarily in parous mice and is rare in nulliparous mice. We determined the effect of Loxl1 deficiency on postpartum regulation of connective tissue metabolism genes and degradative enzyme activity in the vagina at 20 days gestation or 4 h, 48 h, 7 days, 15 days, 25 days, 7 weeks, or 12 weeks postpartum. Nulliparous Loxl1 KO and wildtype (WT) mice aged 11, 18, or 23 weeks were controls. Gene expression and enzyme activity were assessed using real-time quantitative reverse transcription PCR and fluorescein conjugated gelatin zymography, respectively. Parity, but not aging, had a significant influence on gene expression both with time postpartum and between KO and WT mice. Mmp2, Timp1, Timp2, Timp3, Timp4, Col1a1, Col3a1, Acta2, and Bmp1 were differentially expressed between KO and WT mice. Correlational analysis of gene-gene pairs revealed 10 significant differences between parous KO and WT groups, 5 of which were due to lack of co-expression of Bmp1 in KO mice. The overall enzyme activity that could be attributed to MMPs was significantly higher in WT compared to KO mice both 25 days and 12 weeks postpartum, and MMP activity was significantly lower 15 days and 25 days postpartum compared to KO nulliparous controls, but not WT. These findings suggest that Loxl1 deficiency combined with parity has a significant impact on postpartum regulation of connective tissue metabolism, particularly as it relates to co-expression of Bmp1 and altered proteolytic activity.

Evaluation of extracellular matrix protein expression and apoptosis in the uterosacral ligaments of patients with or without pelvic organ prolapse

INTRODUCTION AND HYPOTHESIS

This study aimed to compare the expression levels of extracellular matrix (ECM) and apoptosis proteins in the uterosacral ligament (USL) of patients with and without pelvic organ prolapse (POP).

METHODS

The USL were obtained from patients with POP-Q ≥ III (n = 35) and without POP (n = 20). Immunohistochemistry (IHC) staining and RT-qPCR were conducted to assess the protein and mRNA levels, respectively. The levels of type I collagen (COLI), type III collagen (COLIII), matrix metalloproteinase (MMP)1, MMP2, MMP9, tissue inhibitor of metalloproteinase (TIMP)1, TIMP2, estrogen receptor (ER)α, ERβ and apoptosis-related gene B cell lymphoma 2 (Bcl-2)-associated agonist of cell death (Bad) and Bcl-2-associated X (Bax) in the USL were analyzed.

RESULTS

The protein expression and mRNA levels of MMP2 and MMP9, mRNA levels of BAD and BAX, and protein expression of active cleaved-Caspase3 were significantly higher in the POP group. There were no evident differences in COLIII, MMP1 or ERβ expression at either the mRNA or protein level or in TIMP1, TIMP2 or Caspase3 by IHC between the two groups. However, obvious decreases in COLI and ERα were evident at both the mRNA and protein levels in the POP group, and the mRNA levels of TIMP1 and TIMP2 were also decreased compared to those of the control group.

CONCLUSION

ECM in the USL tissues of POP patients is remodeled compared with non-POP patients and is characterized by decreased synthesis and increased degradation of collagen; moreover, the levels of the main proteins involved in apoptosis are increased in POP tissue.

BMP-1 disrupts cell adhesion and enhances TGF-β activation through cleavage of the matricellular protein thrombospondin-1

Bone morphogenetic protein 1 (BMP-1) is an important metalloproteinase that synchronizes growth factor activation with extracellular matrix assembly during morphogenesis and tissue repair. The mechanisms by which BMP-1 exerts these effects are highly context dependent. Because BMP-1 overexpression induces marked phenotypic changes in two human cell lines (HT1080 and 293-EBNA cells), we investigated how BMP-1 simultaneously affects cell-matrix interactions and growth factor activity in these cells. Increasing BMP-1 led to a loss of cell adhesion that depended on the matricellular glycoprotein thrombospondin-1 (TSP-1). BMP-1 cleaved TSP-1 between the VWFC/procollagen-like domain and the type 1 repeats that mediate several key TSP-1 functions. This cleavage induced the release of TSP-1 C-terminal domains from the extracellular matrix and abolished its previously described multisite cooperative interactions with heparan sulfate proteoglycans and CD36 on HT1080 cells. In addition, BMP-1-dependent proteolysis potentiated the TSP-1-mediated activation of latent transforming growth factor-β (TGF-β), leading to increased signaling through the canonical SMAD pathway. In primary human corneal stromal cells (keratocytes), endogenous BMP-1 cleaved TSP-1, and the addition of exogenous BMP-1 enhanced cleavage, but this had no substantial effect on cell adhesion. Instead, processed TSP-1 promoted the differentiation of keratocytes into myofibroblasts and stimulated production of the myofibroblast marker α-SMA, consistent with the presence of processed TSP-1 in human corneal scars. Our results indicate that BMP-1 can both trigger the disruption of cell adhesion and stimulate TGF-β signaling in TSP-1-rich microenvironments, which has important potential consequences for wound healing and tumor progression.

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.

Genome‑wide DNA methylation analysis of uterosacral ligaments in women with pelvic organ prolapse

Pelvic organ prolapse (POP) is an increasingly serious health problem that impairs quality of life and is caused by multiple additive genetic and environmental factors. As the uterosacral ligaments (ULs) provide primary support for the pelvic organs, it was hypothesized that disruption of these ligaments (as a result of aberrant methylation) may lead to a loss of support and eventually contribute to POP. In the present study, whether there are any aberrant methylations in the ULs of patients with POP compared to those of controls was investigated. Genomic DNA was isolated from the ULs of five women with POP and four women without POP, as controls, undergoing hysterectomy for benign conditions. An Illumina Infinium Methylation EPICBeadChips Infinium Human Methylation 850 K bead array was used to investigate the total methylation in the ULs. There were 3,723 differentially methylated CpG sites (Δβ<0.14; P<0.05), including 3,576 hypermethylation and 147 hypomethylation sites in the ULs of patients with POP compared with the normal controls. There were more hypermethylated CpG sites, but a high ratio of hypomethylation between CpG islands and the N-shelf; in the gene structure, there was more hypermethylation than hypomethylation in TSS1500 and the 5′ untranslated region. Gene ontology analysis demonstrated that these differentially methylated genes were associated with ‘cell morphogenesis’, ‘extracellular matrix’, ‘cell junction’, ‘protein binding’ and ‘guanosine triphosphatase activity’. Several significant pathways were identified, including ‘focal adhesion’ and ‘extracellular matrix-receptor interaction pathway’. This study provides evidence that there are differences in genome-wide DNA methylation between ULs in menopausal women with and without POP, and that epigenetic mechanisms may partly contribute to POP pathogenesis.

Surgical Updates in the Treatment of Pelvic Organ Prolapse

Pelvic organ prolapse affects approximately 8% of women, and the demand for pelvic organ prolapse surgery is expected to increase by nearly 50% over the next 40 years. The surgical techniques used to correct pelvic organ prolapse have evolved over the last 10 years, with multiple well-designed studies addressing the risks, outcomes, reoperation rates, and optimal surgical approaches. Here we review the most recent evidence on the route of access, concomitant procedures, and synthetic materials for augmenting the repair. Ultimately, this review highlights that there is no optimal method for correcting pelvic organ prolapse and that the risks, benefits, and approaches should be discussed in a patient-centered, goal-oriented approach to decision-making.