The role of GPX1 in the pathogenesis of female pelvic organ prolapse

SOCS3, Transcriptionally Activated by NR4A1, Induces Apoptosis and Extracellular Matrix Degradation of Vaginal Fibroblasts in Pelvic Organ Prolapse

Background

Pelvic organ prolapse (POP) is a common gynecological chronic disorder. Human vaginal fibroblasts (HVFs) that maintain the integrity of vaginal wall tissues are essential for keeping pelvic organs in place. Apoptosis and the degradation of the extracellular matrix in HVFs contribute to the progression of POP. The cytokine signal transduction inhibitor 3 (SOCS3) exerts significant regulatory effects on cell signal transduction pathways, thereby affecting various pathological processes.

Aims

To explore the role and mechanism of SOCS3 on HVFs in the context of POP.

Study Design

In vitro cell lines and human-sample study.

Methods

Anterior vaginal wall tissues were obtained from POP or non-POP patients for the analysis of SOCS3 expression. HVFs were isolated from the vaginal tissues of POP patients, and SOCS3 was either overexpressed or knocked down in HVFs via lentivirus infection. Subsequently, the biological function and mechanism of SOCS3 in HVFs were investigated.

Results

SOCS3 was highly expressed in the vaginal tissues of POP patients compared to non-POP patients. Functionally, the overexpression of SOCS3 suppressed cell viability while promoting cell apoptosis in HVFs. The overexpression of SOCS3 also accelerated extracellular matrix degradation (decreasing collagen I, collagen III, and elastin, and increasing MMP2 and MMP9). In terms of mechanism, NR4A1 transcriptionally activated SOCS3 by binding to its promoter. Furthermore, rescue experiments revealed that SOCS3 knockdown hindered NR4A1 overexpression-induced cell apoptosis and extracellular matrix degradation in HVFs.

Conclusion

SOCS3 mediated the apoptotic and extracellular matrix degradation effects of NR4A1 on HVFs, underlining that the restraining of the SOCS3 expression may be a promising strategy for POP treatment.

Roles and mechanisms of biomechanical-biochemical coupling in pelvic organ prolapse

Pelvic organ prolapse (POP) is a significant contributor to hysterectomy among middle-aged and elderly women. However, there are challenges in terms of dedicated pharmaceutical solutions and targeted interventions for POP. The primary characteristics of POP include compromised mechanical properties of uterine ligaments and dysfunction within the vaginal support structure, often resulting from delivery-related injuries. Fibroblasts secrete extracellular matrix, which, along with the cytoskeleton, forms the structural foundation that ensures proper biomechanical function of the fascial system. This system is crucial for maintaining the anatomical position of each pelvic floor organ. By systematically exploring the roles and mechanisms of biomechanical-biochemical transformations in POP, we can understand the impact of forces on the injury and repair of these organs. A comprehensive analysis of the literature revealed that the extracellular matrix produced by fibroblasts, as well as their cytoskeleton, undergoes alterations in patient tissues and cellular models of POP. Additionally, various signaling pathways, including TGF-β1/Smad, Gpx1, PI3K/AKT, p38/MAPK, and Nr4a1, are implicated in the biomechanical-biochemical interplay of fibroblasts. This systematic review of the biomechanical-biochemical interplay in fibroblasts in POP not only enhances our understanding of its underlying causes but also establishes a theoretical foundation for future clinical interventions.

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 β-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.

Serum trace element levels and activity of enzymes associated with oxidative stress in endometriosis and endometrial cancer

Endometriosis and endometrial cancer are closely related to oxidative stress. However, the direct relationship between copper and zinc levels and oxidative stress in the extracellular and intracellular space remains unclear. The presented study is focused on the determination of serum Zn and Cu levels, glutathione concentration and enzyme activity in three groups: patients diagnosed with endometrial cancer (EC), patients diagnosed with endometriosis (EM), and a healthy control group. Spectrophotometric determination of trace elements revealed that levels of zinc and copper were lower in blood plasma of patients with endometriosis as compared with the other groups; however, there were no significant differences in the Cu/Zn ratio. Furthermore, significantly increased blood serum glutathione levels were detected in both EM and EC groups compared with the control group. While the activity of superoxide dismutase (SOD) was similar across the studied groups, we observed differences in the activity of other enzymes associated with oxidative stress, including glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), between the control group and the EM and EC patients. Additionally, analysis of gene expression based on free circulating mRNA indicated significant differences in the expression of SOD isoenzymes between the patient groups and the control group; expression of GPx isoenzymes was also altered. Obtained results may have potential application in diagnostics as well as monitoring of endometriosis and endometrial cancer.

Exosomes derived from mesenchymal stromal cells: a promising treatment for pelvic floor dysfunction

Pelvic floor dysfunction (PFDs), which include pelvic organ prolapse (POP), stress urinary incontinence (SUI) and anal incontinence (AI), are common degenerative diseases in women that have dramatic effects on quality of life. The pathology of PFDs is based on impaired pelvic connective tissue supportive strength due to an imbalance in extracellular matrix (ECM) metabolism, the loss of a variety of cell types, such as fibroblasts, muscle cells, peripheral nerve cells, and oxidative stress and inflammation in the pelvic environment. Fortunately, exosomes, which are one of the major secretions of mesenchymal stromal cells (MSCs), are involved in intercellular communication and the modulation of molecular activities in recipient cells via their contents, which are bioactive proteins and genetic factors such as mRNAs and miRNAs. These components modify fibroblast activation and secretion, facilitate ECM modelling, and promote cell proliferation to enhance pelvic tissue regeneration. In this review, we focus on the molecular mechanisms and future directions of exosomes derived from MSCs that are of great value in the treatment of PFD.

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.

Single nucleotide polymorphisms, gene expression and serum profile of immune and antioxidant markers associated with postpartum disorders susceptibility in Barki sheep

The objective of this study was to explore the immunological and antioxidant alterations associated with ovine postpartum disorders. Blood samples were collected from 90 adult Barki ewes and allocated into three equal-sized groups (30 ewes each): control group (CG), inflammatory postpartum disorders group (IPG) and non-inflammatory postpartum disorders group (NIPG). PCR-DNA sequencing approach was carried out for TLR4 (256-bp) and SOD (456-bp) genes, and nucleotide sequence variations were noticed to be associated with postpartum disorders resistance/susceptibility. Gene expression profile was also evaluated and levels of IL5, IL6, IL1-ß, TNF alpha, TLR4 and Tollip were significantly up-regulated in ewes affected with postpartum disorders than resistant ones, while SOD and CAT genes pattern elicited an opposite trend. Exploring serum profile also showed a significant increase of IL-1α, IL-1β, IL-6, TNF-α, MDA and NO in IPG compared to their correspond values in NIPG and CG. However, serum levels of IL-10, CAT, GSH and GPx were significantly decreased. This study highlights that SNPs in TLR4 and SOD genes could be genetic markers for postpartum disorders resistance/susceptibility in Barki ewes. Gene expression alongside serum profiles of antioxidant markers could also be used to follow-up the immune status of ewes to build up an effective management protocol.

Expression of COX-2 and Nrf2/GPx3 in the anterior vaginal wall tissues of women with pelvic organ prolapse

PURPOSE

To evaluate COX-2 and Nrf2/GPx3 expressions in the lamina propria of the anterior vaginal wall tissues of women with and without pelvic organ prolapse (POP).

METHODS

Tissue samples of anterior vaginal wall were examined using HE staining, immuohistochemical staining and Western blot for the expressions of COX-2/PGE2, Nrf2/GPx3, MMP2, TIMP1, collagen I and collagen III (n = 35, per group).

RESULTS

Compared with control group, collagen fibers of the anterior vaginal wall were disorganized and discontinuous. Expressions of Nrf2, GPx3, TIMP1, collagen I and collagen III were found significantly lower in POP group (P < 0.05); while, expressions of COX-2, PGE2, and MMP2 were found significantly higher in POP group (P < 0.05). Statistically significant correlations of COX-2 and Nrf2/GPx3 were showed (P < 0.01).

CONCLUSION

We found that the interaction between inflammation and oxidative stress was closely related to the development of POP. This study demonstrates that COX-2 and Nrf2 pathways may be involved in pathogenesis of POP, as promising potential therapeutic targets and agents.

Mechanical Stretching induces the apoptosis of parametrial ligament Fibroblasts via the Actin Cytoskeleton/Nr4a1 signalling pathway

The anatomical positions of pelvic floor organs are maintained mainly by ligaments and muscles. Long-term excessive mechanical tension stimulation of pelvic floor tissue beyond the endurance of ligaments or muscles will lead to the occurrence of pelvic organ prolapse (POP). In addition, cytoskeletal reconstitution is a key process by which cells respond to mechanical stimulation. The aim of the present study was to investigate the protective effect of actin cytoskeleton to resist mechanical stretching (MS)-induced apoptosis in parametrial ligament fibroblasts (PLFs) and the underlying mechanisms. MS provided by a four‑point bending device could significantly induce apoptosis of PLFs from non-POP patients, which exhibited an apoptosis rate close to that of PLFs from POP patients, and the apoptosis rate was higher following latrunculin A (Lat-A, a potent inhibitor of actin) treatment. In addition, Nr4a1 and Bax expression was increased while Bcl-2 and caspase-3 expression was clearly decreased after treatment with MS and Lat-A. However, the apoptosis induced by MS was reduced when the expression of Nr4a1 was downregulated by siRNA. These outcomes reveal a novel mechanism that links the actin cytoskeleton and apoptosis in PLFs by Nr4a1; this mechanism will provide insight into the clinical diagnosis and treatment of POP.

The cytotoxicity of advanced glycation end products was attenuated by UCMSCs in human vaginal wall fibroblasts by inhibition of an inflammatory response and activation of PI3K/AKT/PTEN

Pelvic organ prolapse (POP) occurs when the pelvic organs (bladder, bowel or uterus) herniate into the vagina, causing incontinence, voiding, and bowel and sexual dysfunction, negatively impacting upon a woman's quality of life. Intermediate intermolecular cross-links and advanced glycation cross-links increase in prolapsed tissue. Stem cells are able to participate in tissue repair due to their ability to differentiate into multiple lineages, and thus into various types of connective tissue cells, so they therefore hold great promise for treating pelvic floor dysfunction. The current study found that advanced glycation end products (AGEs) inhibited the viability and proliferation of human vaginal wall fibroblasts (VWFs), were cytotoxic to VWFs, and also induced the apoptosis of VWFs. In contrast, umbilical cord-derived mesenchymal stem cells (UCMSCs) secreted anti-inflammation cytokines to protect against the cytotoxic effects of fibroblasts induced by AGEs and attenuated the cytotoxic effect of AGE on fibroblasts by activation of the PI3K/Akt-PTEN pathway. This study demonstrated that UCMSCs inhibited the cytotoxic effect of AGE in cells from patients with POP by inducing an anti-inflammatory reaction and activating the PI3K/AKT/PTEN signaling pathway. The current results provide important insights into use of stem cells to treat POP.

Klotho Protein Reduced the Expression of Matrix Metalloproteinase-1 (MMP-1) and Matrix Metalloproteinase-3 (MMP-3) in Fibroblasts from Patients with Pelvic Organ Prolapse (POP) by Down-Regulating the Phosphorylation of ERK1/2

Background

Pelvic organ prolapse (POP) is due to age-related atrophy and the weakening of the tissues of the pelvic floor, with degradation of collagen and extracellular matrix (ECM) by metalloproteinases (MMPs). This study aimed to investigates the role of the age-related enzyme klotho, encoded by the KL gene, in cultured fibroblasts obtained from patients with POP and the levels of reactive oxygen species (ROS), interleukin-6 (IL-6), and MMPs.

Material/Methods

Pelvic floor fibroblasts were obtained from connective tissue from three patients with POP and three normal subjects. Cell proliferation and ROS production were measured using a cell counting kit-8 (CCK-8) assay and flow cytometry. Levels of interleukin-6 (IL-6), klotho, metalloproteinase-1 (MMP-1), MMP-3, extracellular signal-regulated kinases 1/2 (ERK1/2), and p-ERK1/2 were measured by enzyme-linked immunoassay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot.

Results

In cultured pelvic floor fibroblasts from patients with POP, the expression of klotho protein and klotho mRNA were significantly down-regulated in fibroblasts from patients with POP compared with normal fibroblasts. Klotho supplementation in cultured fibroblasts for patients with POP included increased cell growth, reduced expression of ROS reduction, and reduced the secretion of IL-6. Using qRT-PCR and Western blot, klotho supplementation of fibroblasts from patients with POP increased cell growth and reduced the levels of IL-6 and ROS in a dose-dependent way.

Conclusions

Klotho protein reduced the expression of MMP-1 and MMP-3 in fibroblasts from patients with POP by down-regulating the phosphorylation of ERK1/2.

Protective Role of Nuclear Factor Erythroid-2-Related Factor 2 against Mechanical Trauma-Induced Apoptosis in a Vaginal Distension-Induced Stress Urinary Incontinence Mouse Model

Apoptosis and oxidative damage are involved in the pathogenesis and progression of stress urinary incontinence (SUI). Our previous results indicate that cell apoptosis and oxidative damage increase in a mouse model of mechanical injury-induced SUI and in fibroblasts treated with excessive mechanical strain. Nuclear factor erythroid-2-related factor 2 (Nrf2) is a well-characterized global antioxidant gene inducer that can reduce oxidative damage and apoptosis. Therefore, we predicted that Nrf2 may have a protective role in mechanical trauma-induced SUI. To test this hypothesis, a mouse model of vaginal distension- (VD-) induced SUI was established. Leak point pressure (LPP); levels of apoptosis, apoptosis-related proteins, and peroxidation products; and the activities of antioxidative proteins in the anterior vaginal wall were measured in wild-type (Nfe2l2^+/+) C57BL/6 mice and Nrf2-knockout mice (Nfe2l2^−/−). The results showed that Nrf2 knockout aggravated VD-induced reduction in LPP, increase in cell apoptosis and peroxidation product levels, decrease in antioxidative protein activities, and alterations in apoptosis-related protein levels in the vaginal walls of mice. To further confirm the role of Nrf2 in mechanical trauma-induced apoptosis and SUI, VD was performed on mice overexpressing Nrf2 via in vivo transfection of LV-Nfe2l2. The results showed that Nrf2 overexpression significantly alleviated VD-induced abnormalities in the anterior vaginal wall. Taken together, our data suggested that Nrf2 is a potential protective factor in mechanical trauma-induced apoptosis in a mouse model of SUI. Antioxidative therapy may be a promising treatment for mechanical trauma-related SUI.