Molecular aspects of collagenolysis associated with stress urinary incontinence in women with urethral hypermobility vs intrinsic sphincter deficiency

The Role of Gap Junctions in the Generation of Smooth Muscle Cells from Bone Marrow Mesenchymal Stem Cells

Background. Studies have shown that stem cell transplantation can improve smooth muscle cell (SMC) regeneration and remodelling. Gap junctions can enhance the cytoprotective effects of neighbouring cells. We investigated the effect of gap junctions on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into SMCs. Materials and Methods. Rat BMSCs and SMCs were obtained from the bone marrow and bladder of Sprague-Dawley rats, respectively. Flow cytometry and multilineage differentiation were performed to assess the characteristics of these cells. BMSCs and SMCs were incubated together in cocultures in the presence and absence of heptanol, an uncoupler of gap junctions. Cocultures were divided into three groups consisting of a contact coculture, noncontact coculture, and contact coculture plus heptanol groups. The expression of BMSC-specific markers and the effect of gap junctions on the differentiation of BMSCs were evaluated by performing real-time reverse transcription-polymerase chain reaction, immunofluorescence analysis, and western blotting after cocultures. Results. CD90 and CD44 were markedly expressed, and CD31 and CD45 were weakly or not expressed in BMSCs. The cells also showed good osteogenic and adipogenic differentiation ability. Compared with the noncontact coculture group, the SMC markers such as α-SMA, calponin, and connexin43 increased in the contact coculture group. The effect of contact in the coculture group was significantly weakened by heptanol. Conclusions. The results suggested that gap junctions play an important role in the generation of SMCs from BMSCs. The formation of SMCs can potentially be used to repair the sphincter muscle of patients with stress urinary incontinence.

Associations between metabolic syndrome and female stress urinary incontinence: a meta-analysis

INTRODUCTION AND HYPOTHESIS

The objective was to identify the associations between metabolic syndrome (MS) and stress urinary incontinence (SUI) in women and to provide an evidence base for clinical practice.

METHODS

A meta-analysis of cohort, case-control, and cross-sectional studies about the association between MS and SUI was performed using databases including PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine disc (CBMdisc), Wanfang Database (WanFang Data), and VIP database (VIP). The time limit was from the commencement of each database to 1 November 2020. Two researchers independently screened literature, extracted data, and assessed the risk of bias. RevMan 5.3 software was used for statistical analysis. The dichotomous variables were presented as the risk ratio (odds ratio, OR) and 95% CI as the effect indicators.

RESULTS

Six studies were included in the meta-analysis, with a total sample size of 3,678 cases. The results showed that the risk for SUI in women with MS was three times those without MS (OR = 3.41, 95% CI 2.01, 5.77, p <0.00001), and the difference was statistically significant. The results of subgroup analysis showed that MS was significantly associated with SUI in the subgroups of pre- and postmenopausal women (OR = 2.46, 95% CI 1.63, 3.73, p < 0.00001), and in the subgroups of other types of women (OR = 3.41, 95% CI 2.01, 5.77, p = 0.0003), and the differences were statistically significant.

CONCLUSIONS

Metabolic syndrome is associated with SUI in women and increases its risk.

Secretomes of human pluripotent stem cell-derived smooth muscle cell progenitors upregulate extracellular matrix metabolism in the lower urinary tract and vagina

BACKGROUND

Adult mesenchymal stem cells (MSCs) have been studied extensively for regenerative medicine; however, they have limited proliferation in vitro, and the long culture time induces cell senescence. MSCs also contribute to tissue repair through their paracrine function. In this study, we sought to examine the paracrine effects of human smooth muscle cell progenitors (pSMC) on the urethra and adjacent vagina of stress urinary incontinence rodents. We use human pluripotent stem cell (PSC) lines to derive pSMCs to overcome the issue of decreased proliferation in tissue culture and to obtain a homogenous cell population.

METHOD

Three human PSC lines were differentiated into pSMCs. The conditioned medium (CM) from pSMC culture, which contain pSMC secretomes, was harvested. To examine the effect of the CM on the extracellular matrix of the lower urinary tract, human bladder smooth muscle cells (bSMCs) and vaginal fibroblasts were treated with pSMC-CM in vitro. Stress urinary incontinence (SUI) was induced in rats by surgical injury of the urethra and adjacent vagina. SUI rats were treated with pSMC-CM and monitored for 5 weeks. Urethral pressure testing was performed prior to euthanasia, and tissues were harvested for PCR, Western blot, and histological staining. Kruskal-Wallis one-way ANOVA test and Student t test were used for statistical comparisons.

RESULTS

pSMC-CM upregulated MMP-2, TIMP-2, collagen, and elastin gene expression, and MMP-9 activity in the human bladder and vaginal cells consistent with elastin metabolism modulation. pSMC-CM treatment in the SUI rat improved urethral pressure (increase in leak point pressure compared to intact controls, p < 0.05) and increased collagen and elastin expression in the urethra and the adjacent vagina.

CONCLUSION

Conditioned media from smooth muscle cell progenitors derived from human pluripotent stem cells improved urethral leak point pressure and collagen and elastin content in the SUI rat. These findings suggest a novel therapeutic potential for PSC-based treatments for SUI and pelvic floor disorders where tissues are affected by collagen, elastin, and smooth muscle loss.

Research progress of single nucleotide polymorphism in stress urinary incontinence

Stress urinary incontinence (SUI), as one of the manifestations of pelvic floor dysfunction diseases with high incidence, seriously affects women's physical and mental health and quality of life. The etiology and pathogenesis of SUI are complex and not yet completely clear, now believed to be involved with environmental factors, genetic factors and cross-cutting factors between the two. SUI genetic susceptibility may be related to single nucleotide polymorphism. This article reviews the current studies on SUI-related single nucleotide polymorphisms.