HOXA11 promotes fibroblast proliferation and regulates p53 in uterosacral ligaments

Comparative computational analysis to distinguish mesenchymal stem cells from fibroblasts

Introduction

Mesenchymal stem cells (MSCs) are considered to be the most promising stem cell type for cell-based therapies in regenerative medicine. Based on their potential to home to diseased body sites following a therapeutically application, these cells could (i) differentiate then into organ-specific cell types to locally restore injured cells or, most prominently, (ii) foster tissue regeneration including immune modulations more indirectly by secretion of protective growth factors and cytokines. As tissue-resident stem cells of mesenchymal origin, these cells are morphologically and even molecularly- at least concerning the classical marker genes- indistinguishable from similar lineage cells, particularly fibroblasts.

Methods

Here we used microarray-based gene expression and global DNA methylation analyses as well as accompanying computational tools in order to specify differences between MSCs and fibroblasts, to further unravel potential identity genes and to highlight MSC signaling pathways with regard to their trophic and immunosuppressive action.

Results

We identified 1352 differentially expressed genes, of which in the MSCs there is a strong signature for e.g., KRAS signaling, known to play essential role in stemness maintenance, regulation of coagulation and complement being decisive for resolving inflammatory processes, as well as of wound healing particularly important for their regenerative capacity. Genes upregulated in fibroblasts addressed predominately transcription and biosynthetic processes and mapped morphological features of the tissue. Concerning the cellular identity, we specified the already known HOX code for MSCs, established a potential HOX code for fibroblasts, and linked certain HOX genes to functional cell-type-specific properties. Accompanied methylation profiles revealed numerous regions, especially in HOX genes, being differentially methylated, which might provide additional biomarker potential.

Discussion

Conclusively, transcriptomic together with epigenetic signatures can be successfully be used for the definition (cellular identity) of MSCs versus fibroblasts as well as for the determination of the superior functional properties of MSCs, such as their immunomodulatory potential.

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.

Downregulation of hsa-miR-548d-3p and overexpression of HOXA9 in diffuse large B-cell lymphoma patients and the risk of R-CHOP chemotherapy resistance and disease progression

INTRODUCTION

Routine categorization of DLBCL patients into GCB and non-GCB groups by Hans' criteria could not accurately predict chemotherapy resistance and disease progression in patients treated with standard R-CHOP therapy. There is a need to identify better biomarker predictors to enhance assisted selection of chemotherapy regimens for DLBCL patients.

AIM OF THE STUDY

To identify dysregulated miRNAs and mRNAs that are predictive of resistance to R-CHOP chemotherapy or disease progression in patients with DLBCL.

METHODS

miRNA and mRNA profiling were performed on archival FFPE samples of the DLBCL patients. miRabel and miRNet bioinformatic tools were applied to determine experimental validated miRNA-mRNA target interaction. The significance of the genomic predictive values was assessed using adjusted odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS

19/36 were R-CHOP therapy-resistant whilst 17/36 were R-CHOP therapy-sensitive. Ten dysregulated miRNAs and 12 dysregulated mRNAs were identified in therapy-resistant DLBCL patients. These dysregulated miRNAs and mRNA cause therapy resistance and disease progression in DLBCL patients, most likely via upregulation of the anti-apoptotic protein bcl2, activation of the JAK/STAT signalling pathway and dysregulation of p53 pathway. Downregulation of hsa-miR-548d-3p and overexpression of HOXA9 mRNA were significantly associated with therapy resistance and disease progression in DLBCL patients [hsa-miR-548d-3p AOR: 0.258, 95%CI: 0.097-0.684, p = 0.006].

CONCLUSION

DLBCL patients with downregulation of hsa-miR-548d-3p and overexpression of HOXA9 mRNA are more likely to experience R-CHOP therapy resistance and disease progression.

ATF3 regulates oxidative stress and extracellular matrix degradation via p38/Nrf2 signaling pathway in pelvic organ prolapse

Pelvic organ prolapse (POP) is a common disorder in women, and it is characterized by weakening of pelvic supportive structure with extracellular matrix (ECM) degradation. Activating transcription factor 3 (ATF3) was upregulated in anterior vaginal wall tissues of POP patients. We hypothesized that upregulation of ATF3 might contribute to POP development. This study aims to unveil the role of ATF3 in the pathogenesis of POP using a H₂O₂-induced in vitro model. Vaginal fibroblasts were isolated from woman with POP-Q stage greater than II and asymptomatic women with normal pelvic floor support. Knockdown of ATF3 enhanced cell viability and decreased cell apoptosis. Flow cytometry and immunnofluorescence showed that ATF3 deficiency inhibited H₂O₂-induced ROS production and the expression of 8 OHdG and 4-HNE. Western blot and Real-time PCR analysis revealed that ATF3 deficiency attenuated ECM component degradation (increasing collagen I, collagen III and elastin) and MMPs/TIMPs imbalance (decreasing MMP2 and MMP9 and increasing TIMP2). Moreover, knockdown of ATF3 induced the activation of p38/Nrf2/HO-1 signaling pathway. Further treatment with p38 inhibitor SB203580 abolished the protection of ATF3 deficiency against H₂O₂-induced cell damage, which was reverted by Nrf2 activator TBHQ. Thus, ATF3 likely contributes to POP progression by inducing cell apoptosis, oxidative stress and ECM degradation via regulating p38/Nrf2 pathway, which provides a potential therapeutic target for 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.

Using the novel pelvic organ prolapse histologic quantification system to identify phenotypes in uterosacral ligaments in women with pelvic organ prolapse

BACKGROUND

Pelvic organ prolapse is common, but the underlying etiologies are poorly understood, which limits our current prevention and treatment options.

OBJECTIVE

Our primary objective was to compare the uterosacral ligament histologic features in women with and without prolapse using the novel pelvic organ prolapse histologic quantification system. Our secondary aim was to determine whether composite histologic findings in uterosacral ligaments are associated with prolapse risk factors.

STUDY DESIGN

This was a prospective cohort study in which paracervical uterosacral ligament biopsies were performed at the time of hysterectomy for primary prolapse or other benign gynecologic indications and processed for histologic evaluation. The pelvic organ prolapse quantification system was used to determine the prolapse stage. In this study, 9 prominent histologic features were semiquantitatively scored using the pelvic organ prolapse histologic quantification system in a blinded fashion and compared between prolapse and control groups. Unbiased principal component analysis of these scores was independently performed to identify potential relationships between histologic measures and prolapse risk factors.

RESULTS

The histologic scores of 81 prolapse and 33 control ligaments were analyzed. Compared with the control group, women in the prolapse group were significantly older and more likely to be in the menopausal phase. There was no difference in the number of vaginal deliveries, body mass index, hormone use, or smoking status between the groups. To control for baseline differences, patients were also stratified by age over 40 years and menopausal status. Compared with the control group, the prolapse ligaments in the premenopausal group had significantly more loss of smooth muscle fibers within the fascicles (P<.001), increased inflammatory infiltrates of neutrophils within the tissue and perineural inflammatory cells (P<.01 and P=.04, respectively), and reduced neointimal hyperplasia (P=.02). Prolapse ligaments in the postmenopausal group exhibited elevated adipose content compared with that of the control group (P=.05). Amount of fibrillar collagen, total nonvascular smooth muscle, and muscle fiber vesicles of prolapse ligaments did not differ in either the premenopausal or postmenopausal group compared with that of the control group. Unbiased principal component analysis of the histologic scores separated the prolapse ligaments into 3 phenotypes: (1) increased adipose accumulation, (2) increased inflammation, and (3) abnormal vasculature, with variable overlap with controls. Posthoc analysis of these subgroups demonstrated a positive correlation between increasing number of vaginal deliveries and body mass index with increasing adipose content in the adipocyte accumulation and inflammatory phenotype and increasing neointimal hyperplasia in the vascular phenotype. However, only the relationship between vaginal delivery and adipocytes was significant in the adipose phenotype (R²=0.13; P=.04).

CONCLUSION

Histologic phenotypes exist in pelvic support ligaments that can be distinguished using the pelvic organ prolapse histologic quantification system and principle component analysis. Vaginal delivery is associated with aberrant adipose accumulation in uterosacral ligaments. Our findings support a multifactorial etiology for pelvic organ prolapse contributing to altered smooth muscle, vasculature, and connective tissue content in crucial pelvic support structures. To confirm these associations and evaluate the biomechanical properties of histologic phenotypes of prolapse, larger studies are warranted. Closing this gap in knowledge will help optimize personalized medicine and help identify targets for prevention and treatment of this complex condition.

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.

Expressions of homeobox, collagen and estrogen genes in women with uterine prolapse

OBJECTIVE

Genetic contribution is thought to be involved in the pathophysiology of pelvic organ prolapse (POP). We aimed to study the gene expression profiles of the genes HomeoboxA11 (HOXA11), HomeoboxA13 (HOXA13), Collagen Type I (COL1A), Collagen Type III (COL3A), estrogen receptor genes (ESR1 and ESR2) of round (RL) and uterosacral ligaments (USL) in postmenopausal women with uterine prolapse.

STUDY DESIGN

Gene expressions of 32 postmenopausal women with prolapse were analysed according to gene expressions of 8 postmenopausal women without prolapse. Quantitative real-time PCR (qRT-PCR) method was used for the detection of expression levels of the genes. Student's t-Test and Mann-Whitney U test were used for statistical analysis.

RESULTS

In the USL specimens of all women with uterine prolapse HOXA13 and ESR1 gene expressions were decreased compared to controls (0.5 fold, p = 0.04 and 0.82 fold, p = 0.04, respectively). In the RL specimens, ESR2 gene expression was decreased 0.7 fold in women with prolapse when compared to controls (p = 0.04). In the USL specimens of women with advanced stages of prolapse (stage ≥3), HOXA13 and COL3A gene expressions were decreased compared to controls (0.44 fold, p = 0.043 and 0.39 fold, p = 0.045, respectively). In the RL specimens, ESR2 gene expression was decreased 0.65 fold in women with prolapse when compared to controls (p = 0.052).

CONCLUSION

The significant decrease in the expression of the genes HOXA13, COL3A in the USL and ESR2 in the RL especially in advanced stages of prolapse, implicate that these gene expressions may play a role in the development of uterine prolapse.

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.

2D USS of the pelvic floor in the 3rd trimester versus mode of delivery

OBJECTIVE

Biomechanics of pelvic floor muscles is becoming an important field of research in understanding a complex process of labour. Current evidence indicates that the levator ani stretches to allow passage of the fetus through the birth canal. We sought to identify properties of the functional female pelvic floor during pregnancy that could help to predict the mode of delivery, especially in women who underwent caesarean section in the past.

METHODS

A single centre prospective cohort study of pregnant women in the 3rd trimester attending antenatal clinic. Participants were categorised into three groups: 1. nulliparous, 2. previous one vaginal delivery and 3. previous one caesarean section who chose a trial of labour in their current pregnancy. All women underwent ultrasonographic evaluation of their pelvic floor muscles. Distensibility and the mode of delivery were assessed in participants' current pregnancies. The primary outcome was the mode of delivery. ANOVA test was used for statistical analysis.

RESULTS

133 women were included: 55 nulliparous, 52 primiparous (previous one vaginal birth), and 26 primiparous (previous one LSCS and planned for vaginal delivery after caesarean (VBAC)). Participants were scanned at an average gestation of 32 weeks. The inter-observer reliability test for puborectalis distensibility was good (kappa 0.75). Overall, women who delivered vaginally had a more distensible puborectalis muscle than those who delivered by emergency LSCS regardless of their previous type of delivery. Women who underwent a successful VBAC had less distensible pelvic floor muscles compared to their nulliparous and primiparous counterparts (who delivered vaginally in the past).

CONCLUSION

These results support our basic conceptual theory of puborectalis muscle distensibility influencing the mode of delivery and endorse application of dynamic pelvic floor ultrasound in future studies. We identified measurable differences in the functional female pelvic anatomy aiding a better understanding of physiology of the labour. There are trends towards lesser distensibility in women who delivered by LSCS.

MicroRNA-30d and microRNA-181a regulate HOXA11 expression in the uterosacral ligaments and are overexpressed in pelvic organ prolapse

The balanced turnover of collagen is necessary to maintain the mechanical strength of pelvic supportive connective tissues. Homeobox (HOX) A11 is a key transcriptional factor that controls collagen metabolism and homoeostasis in the uterosacral ligaments (USLs), and the deficient HOXA11 signalling may contribute to alterations in the biochemical strength of the USLs, leading to pelvic organ prolapse (POP). However, it is unknown how HOXA11 transcripts are regulated in the USLs. In this study, we found that microRNA (miRNA)-30d and 181a were overexpressed in women with POP, and their expression was inversely correlated with HOXA11 mRNA levels. The overexpression of miR-30d or 181a suppressed HOXA11 mRNA and protein levels in 293T cells, whereas the knockdown of these miRNAs enhanced HOXA11 levels and collagen production. Cotransfection of a luciferase reporter plasmid containing the 3′-untranslated region of HOXA11 with miR-30d or 181a mimic resulted in decreased relative luciferase activity. Conversely, cotransfection with anti-miR-30d or 181a increased luciferase activity. Taken together, these results indicate that both miR-30d and 181a are important posttranscriptional regulators of HOXA11 in the USLs and could be a potential therapeutic target for POP.

HOXA11 and MMP2 gene expression in uterosacral ligaments of women with pelvic organ prolapse

OBJECTIVE

Pelvic organ prolapse (POP) is a common disorder that negatively impacts the quality of life in many women. Uterosacral ligaments (USLs) are supportive structures of the pelvic organs that are often attenuated in women with POP. The HOXA genes regulate the development of the uterosacral ligaments. We compared expression of HOXA11 and MMP2 in USLs of women with and without POP.

MATERIAL AND METHODS

A prospective sequential cross sectional study was conducted in ZTB Women's Health Research and Education Hospital. We compared expression of HOXA11 and MMP2 in USLs of women with (n:18) and without (n: 15) POP. Total RNA was isolated from patient (n:18) and control (n:15) uterosacral ligament tissues with TriPure isolation reagent according to the manufacturer's instructions. Expression levels of HOXA11 and MMP2 were determined using semiquantitative RT-PCR in a Light Cycler 480 system. Real-time ready catalog assays, which are short FAM-labeled hydrolysis probes containing locked nucleic acid, were used for RT-PCR reactions.

RESULTS

There was no difference in patients' mean age, parity, body mass indexes, and menopausal status between two groups. Means of RNA expression of MMP2 were 1.27±0.6 and 0.75±0.4 in the POP group vs control group, respectively (p:0.007). Means of RNA expression of HOXA 11 were 2.57±2.4 and 1.94±1.4 in the POP group vs control group, respectively (p:0.376). The POP group was divided as mild and severe POP; there was no difference in HOXA11 and MMP2 RNA expression between groups (p>0.05).

CONCLUSION

Although there was no difference HOXA11 RNA expression in USLs with the POP group vs control, there was a significant difference MMP2 RNA expression in USLs with the POP group vs control. There are limited studies on this subject, and study results are contradictory. Further investigations with larger numbers of cases are needed to clarify this subject.

Animal models of female pelvic organ prolapse: lessons learned

Pelvic organ prolapse is a vaginal protrusion of female pelvic organs. It has high prevalence worldwide and represents a great burden to the economy. The pathophysiology of pelvic organ prolapse is multifactorial and includes genetic predisposition, aberrant connective tissue, obesity, advancing age, vaginal delivery and other risk factors. Owing to the long course prior to patients becoming symptomatic and ethical questions surrounding human studies, animal models are necessary and useful. These models can mimic different human characteristics - histological, anatomical or hormonal, but none present all of the characteristics at the same time. Major animal models include knockout mice, rats, sheep, rabbits and nonhuman primates. In this article we discuss different animal models and their utility for investigating the natural progression of pelvic organ prolapse pathophysiology and novel treatment approaches.

Hoxa-11 maintains cell proliferation in the mouse gubernaculum to facilitate testicular descent

INTRODUCTION

The gubernaculum is a structure vital for guiding testicular descent. The Homeobox gene, Hoxa-11, is involved in patterning embryonic structures and is necessary for gubernacular development, as Hoxa-11 knock-out mice exhibit abnormal gubernacula and undescended testes. We aimed to elucidate how testicular descent fails by examining cell proliferation and androgen receptor (AR) expression in Hoxa-11 KO mice gubernacula.

METHODS

Postnatal day 2 wild type (n=6) and Hoxa-11 KO mice (n=6), were prepared for immunohistochemistry and confocal microscopy using antibodies against androgen receptor, slow skeletal myosin (My32), and Ki67, a marker of cell proliferation.

RESULTS

The gubernacula of Hoxa-11 KO mice were hypocellular compared with WT. AR was present in the gubernaculum and abutting inguinal fat pad in both WT and Hoxa-11 KO with no difference in expression. Slow skeletal myosin was present in a clear 'swirl' in the growth centre of WT animals which was absent in the Hoxa-11 KO mice. Ki67, expressed in the growth centre and cremaster muscle in WT, was greatly decreased in Hoxa-11 KO.

CONCLUSION

Hoxa-11 may regulate fibroblast proliferation in the gubernaculum, as it does in human uterosacral ligaments, allowing formation of the 'growth centre' within the bulb and facilitating myogenesis and elongation to the scrotum. Polymorphisms in Hoxa-11 may contribute to the aetiology of human cryptorchidism.

Knockdown of Hoxa11 in vivo in the uterosacral ligament and uterus of mice results in altered collagen and matrix metalloproteinase activity

Homeobox (HOX) genes are evolutionarily conserved genes encoding transcription factors that regulate mammalian embryonic growth and development of the urogenital tract. In both humans and mice, HOXA11 persists in the adult reproductive tract and is thought to play an important role in maintaining tissue developmental plasticity by regulating the expression of genes involved in extracellular matrix metabolism in the reproductive organs. Previously, we have shown that HOXA11 is necessary for development of the uterosacral ligaments in mice and is deficient in women with pelvic organ prolapse. Therefore, we hypothesized that Hoxa11 regulates the synthesis and/or metabolism of collagens in the uterosacral ligaments and uterus, and tested this by establishing an in utero and peritoneal Hoxa11 gene knockdown system in C57/BL6 mice using vectors bearing Hoxa11 short hairpin RNA. Specific knockdown of Hoxa11 transcripts and protein levels were confirmed versus control vectors. Protein and mRNA expression of collagen types I and III exhibited significant decreases following Hoxa11 knockdown according to Western blot analysis and real-time PCR. Tissue inhibitor of matrix metalloproteinase 1 (MMP1) expression also exhibited a significant decrease. Gelatinase zymography confirmed increases in pro-MMP2 and MMP9, as well as activated MMP2, following Hoxa11 knockdown. These results reveal that Hoxa11 knockdown in the uterosacral ligaments and uterus increases extracellular matrix degradation. More importantly, it suggests a mechanism in the weakening of the pelvic floor support in women, because decreased HOXA11 gene expression has been reported to be associated with decreased collagen and increased MMP2 expression in the uterosacral ligaments of women with pelvic organ prolapse.