Therapeutic Effect and Mechanism of Electrical Stimulation in Female Stress Urinary Incontinence

Cytokine modulation in pelvic organ prolapse and urinary incontinence: from molecular insights to therapeutic targets

Pelvic organ prolapse (POP) and urinary incontinence (UI) are common disorders that significantly impact women's quality of life. Studies have demonstrated that cytokines, including pro- and anti-inflammatory immune mediators, play a role in illness genesis and progression. Research on the inflammatory milieu of the pelvic floor has shown that POP patients have increased inflammation in vaginal tissues. This evidence revealed that significant changes in the inflammatory milieu of the pelvic floor are an aspect of the pathogenesis of POP. POP patients exhibit increased levels of inflammatory cytokines (IL-1, TNF, IFN, and others) in the front vaginal wall, which may alter collagen metabolism and contribute to POP. Studies indicate that cytokines such as IL-6, IL-10, and TGF, which are involved in inflammation, remodelling, and repair, have dual effects on POP and UI. They can promote tissue healing and regeneration but also exacerbate inflammation and fibrosis, contributing to the progression of these conditions. Understanding the dual roles of these cytokines could help us improve the vaginal microenvironment of women and treat POP and UI. Given the considerable changes in these cytokines, this review addresses studies published between 2000 and 2024 on the molecular mechanisms by which pro- and anti-inflammatory cytokines affect women with POP and UI. Furthermore, we explain novel therapeutic strategies for cytokine regulation, emphasizing the possibility of personalized treatments that address the underlying inflammatory milieu of the vagina in POP and UI patients. This thorough analysis aims to establish a foundation for future research and clinical applications, ultimately improving patient outcomes via designed cytokine-based therapies.

Myostatin Changes in Females with UI after Magnetic Stimulation: A Quasi-Experimental Study

Background and Objectives: Urinary incontinence (UI) is the involuntary loss of urine caused by a weakness in the pelvic floor muscles (PFMs) that affects urethral closure. Myostatin, which prevents the growth of muscles, is a protein expressed by human skeletal muscle cells. Indeed, it has been observed that myostatin concentration rises during skeletal muscle inactivity and that suppressing serum myostatin promotes muscle growth and strength. Furthermore, therapeutic interventions that reduce myostatin signalling may lessen the effects of aging on skeletal muscle mass and function. For this reason, the aim of the study was to assess if flat magnetic stimulation technology affects serum myostatin levels, as myostatin can block cell proliferation at the urethral sphincter level. Materials and Methods: A total of 19 women, 75% presenting stress urinary incontinence (SUI) and 25% urgency urinary incontinence (UUI), were enrolled. A non-invasive electromagnetic therapeutic system designed for deep pelvic floor area stimulation was used for eight sessions. Results: The ELISA (enzyme linked immunosorbent assay) test indicated that the myostatin levels in blood sera had significantly decreased. Patients' ultrasound measurements showed a significant genital hiatus length reduction at rest and in a stress condition. The Pelvic Floor Bother Questionnaire consistently revealed a decrease in mean scores when comparing the pre- and post-treatment data. Conclusions: Effective flat magnetic stimulation reduces myostatin concentration and genital hiatus length, minimizing the severity of urinary incontinence. The results of the study show that without causing any discomfort or unfavourable side effects, the treatment plan significantly improved the PFM tone and strength in patients with UI.

Randomised controlled pilot trial to assess effect of electrical stimulation of weak pelvic floor muscles

INTRODUCTION AND HYPOTHESIS

Pelvic floor muscle training (PFMT) has level 1A scientific evidence for the treatment of urinary incontinence and pelvic organ prolapse. Past studies, however, have often excluded women with very weak pelvic floor muscles (PFM). The aim was to investigate the hypothesis that intravaginal electrical stimulation (iES) improves PFM strength more than PFMT in women with weak PFM, and to use these results to calculate sample size required for a future large randomised controlled trial (RCT).

METHODS

This assessor-blinded pilot RCT had a two arm, parallel design with computer-generated Randomisation. Both groups were offered 12 one-to-one physiotherapy sessions over a 6-month period. The iES group received individual tailored electrical pulse parameters. The PFMT group received PFM exercises, with the addition of facilitation techniques at therapy sessions. A power calculator was used to calculate sample size.

RESULTS

Fifteen women were recruited. Eight were randomised to iES and 7 to PFMT. Two subjects dropped out of the iES group. Median age was 49 years (range 36-77) and parity 2.1 (range 1-3). Both groups showed increases in PFM strength measured by manometery (iES 12.3, SD 12.0 vs PFMT 10.0, SD 8.1) cmH2O. There was no significant difference between groups. With a power of 0.80 we need a sample size of 95 women in each group to detect a difference between groups.

CONCLUSION

There was no significant difference between the groups in improvements in PFM strength. To detect a difference, we would have required 95 women in each group.

Chitin-based hydrogel loaded with bFGF and SDF-1 for inducing endogenous mesenchymal stem cells homing to improve stress urinary incontinence

Nonoperative treatments for Stress Urinary Incontinence (SUI) represent an ideal treatment method. Mesenchymal stem cell (MSCs) treatment is a new modality, but there is a lack of research in the field of gynecological pelvic floor and no good method to induce internal MSC homing to improve SUI. Herein, we develop an injectable and self-healing hydrogel derived from β-chitin which consists of an amino group of quaternized β-chitin (QC) and an aldehyde group of oxidized dextran (OD) between the dynamic Schiff base linkage.it can carry bFGF and SDF-1a and be injected into the vaginal forearm of mice in a non-invasive manner. It provides sling-like physical support to the anterior vaginal wall in the early stages. In the later stage, it slowly releasing factors and promoting the homing of MSCs in vivo, which can improve the local microenvironment, increase collagen deposition, repair the tissue around urethra and finally improve SUI (Scheme 1). This is the first bold attempt in the field of pelvic floor using hydrogel mechanical support combined with MSCs homing and the first application of chitin hydrogel in gynecology. We think the regenerative medicine approach based on bFGF/SDF-1/chitin hydrogel may be an effective non-surgical approach to combat clinical SUI.

Effect of pelvic floor muscle electrical stimulation on lumbopelvic control in women with stress urinary incontinence: randomized controlled trial

INTRODUCTION

The pelvic floor muscle (PFM) plays a role not only in lumbopelvic stabilization, but also in incontinence and sexual function.

OBJECTIVE

This study aimed to determine the effectiveness of PFM training by electrical stimulation (ES) on urinary incontinence, PFM performance (i.e. strength and power), lumbopelvic control, and abdominal muscle thickness in women with stress urinary incontinence (SUI).

METHODS

Participants were randomized into ES and control groups. The ES group underwent PFM ES for 8 weeks, whereas the control group underwent only a walking program. The impact of urinary incontinence on quality of life was assessed by the Incontinence Impact Questionnaire (IIQ)-7. PFM strength and power were measured using a perineometer. Lumbopelvic control was measured by one and double-leg-lowering tests. Abdominal muscle thickness was measured by sonography.

RESULTS

The ES group showed significantly improved IIQ-7 scores and PFM performance, and had significantly higher values in both one and double-leg lowering tests (p < .05) after 8 weeks of training, indicating significant improvement from pre-session values (p < .005). There were no significant between- or within-group differences at rest in abdominal muscle thickness.

CONCLUSION

PFM ES could improve lumbopelvic control and PFM performance, and reduce subjective symptoms of urinary incontinence in women with SUI.

Stress Urinary Incontinence: An Unsolved Clinical Challenge

Stress urinary incontinence is still a frequent problem for women and men, which leads to pronounced impairment of the quality of life and withdrawal from the social environment. Modern diagnostics and therapy improved the situation for individuals affected. But there are still limits, including the correct diagnosis of incontinence and its pathophysiology, as well as the therapeutic algorithms. In most cases, patients are treated with a first-line regimen of drugs, possibly in combination with specific exercises and electrophysiological stimulation. When conservative options are exhausted, minimally invasive surgical therapies are indicated. However, standard surgeries, especially the application of implants, do not pursue any causal therapy. Non-absorbable meshes and ligaments have fallen into disrepute due to complications. In numerous countries, classic techniques such as colposuspension have been revived to avoid implants. Except for tapes in the treatment of stress urinary incontinence in women, the literature on randomized controlled studies is insufficient. This review provides an update on pharmacological and surgical treatment options for stress urinary incontinence; it highlights limitations and formulates wishes for the future from a clinical perspective.

Perspectives on the Therapeutic Effects of Pelvic Floor Electrical Stimulation: A Systematic Review

Pelvic, perineal, and nervous lesions, which derive principally from pregnancy and childbirth, may lead to pelvic floor dysfunctions, such as organ prolapses and lesions in the nerves and muscles due to muscle expansion and physiology. It is estimated that 70% of women affected by this clinical picture have symptoms that do not respond to the classical treatments with antimuscarinic and anticholinergic drugs. Therefore, resorting to efficient alternatives and less invasive methods is necessary to assist this public health problem that predominantly affects the female population, which is more susceptible to the risk factors. This study aimed to perform an updated and comprehensive literature review focused on the effects of pelvic floor electrical stimulation, considering new perspectives such as a correlation between electric current and site of intervention and other molecular aspects, different from the present reviews that predominantly evaluate urodynamic aspects. For that purpose, PubMed and ScienceDirect databases were used to perform the search, and the Methodi ordinatio method was applied. With well-researched therapeutic effects, electrical stimulation induced promising results in histological, nervous, and molecular evaluations and spinal processes, which showed beneficial results and revealed new perspectives on ways to evoke responses in the lower urinary tract in a non-invasive way. Thus, it is possible to conclude that this type of intervention may be a non-invasive alternative to treat pelvic and perineal dysfunctions.

Current State of Non-surgical Devices for Female Stress Urinary Incontinence

PURPOSE OF REVIEW

The purpose of this review is to summarize and assess the current non-surgical devices for the treatment of stress urinary incontinence (SUI).

RECENT FINDINGS

Devices for SUI can generally be divided into two categories. One category is the augmentation of pelvic floor muscle training (PFMT), wherein devices such as vaginal cones, intravaginal biofeedback, and electrical or magnetic stimulation are used to strength the pelvic floor musculature, though none are more effective than traditional PFMT. The second category of devices mechanically occludes the outlet and includes incontinence pessaries, intravaginal occlusion devices, and urethral plugs and patches. While these are palliative rather than curative, they share similar rates of improvement in leakage. A number of novel devices exist for the treatment and management of SUI. Though no single device has been shown to be more effective than PFMT alone, they may be beneficial for women who have difficulty isolating their pelvic floor muscles, desire accountability, or prefer technology-based engagement. Outlet occlusion devices are less comfortable for the patient, but remain an option for women who do not desire surgery.

Puerarin protects fibroblasts against mechanical stretching injury through Nrf2/TGF-β1 signaling pathway

INTRODUCTION AND HYPOTHESIS

Stress urinary incontinence (SUI) is the most common form of urinary incontinence in women, which affects women's quality of life worldwide. Mechanical injury of the pelvic floor may disrupt the pelvic supportive tissues and connections via the remodeling of extracellular matrix (ECM), which is supposed to be one of the main pathological mechanisms of SUI.

METHODS

The SUI mouse model was established using vaginal distension (VD). Leak point pressure (LPP), maximum cystometric capacity (MCC), collagen, Nrf2 and TGF-β1 in the anterior vaginal wall were measured in either wild-type or Nrf2-knockout (Nrf2^-/^-) female C57BL/6 mice with or without puerarin treatment. Then, the mechanical stretching (MS) loaded on L929 cells was generated by a four-point bending device. mTGF-β1 or LY2109761 (an inhibitor of TGF-β1) was used to verify the protective effect of puerarin after Nrf2 knockdown or overexpression.

RESULTS

The collagen content of the anterior vaginal tissues in VD mice and LPP and MCC was decreased significantly. Besides, the expression levels of Nrf2, TGF-β1, collagen I and collagen III of MS group were downregulated in L929 cells. Puerarin pretreatment could reverse mechanical injury-induced collagen downregulation and Nrf2/TGF-β1 signaling inhibition. Moreover, both LY2109761 pretreatment and Nrf2 knockdown could attenuate the protective effect of puerarin in the mechanical injury-induced ECM remodeling, whereas exogenous TGF-β1 could counteract the effect of Nrf2 downregulation.

CONCLUSIONS

Puerarin protected fibroblasts from mechanical injury-induced ECM remodeling through the Nrf2/TGF-β1 signaling pathway. This might be a new strategy for the treatment of SUI.

Molecular Processes in Stress Urinary Incontinence: A Systematic Review of Human and Animal Studies

Stress urinary incontinence (SUI) is a common and burdensome condition. Because of the large knowledge gap around the molecular processes involved in its pathophysiology, the aim of this review was to provide a systematic overview of genetic variants, gene and protein expression changes related to SUI in human and animal studies. On 5 January 2021, a systematic search was performed in Pubmed, Embase, Web of Science, and the Cochrane library. The screening process and quality assessment were performed in duplicate, using predefined inclusion criteria and different quality assessment tools for human and animal studies respectively. The extracted data were grouped in themes per outcome measure, according to their functions in cellular processes, and synthesized in a narrative review. Finally, 107 studies were included, of which 35 used animal models (rats and mice). Resulting from the most examined processes, the evidence suggests that SUI is associated with altered extracellular matrix metabolism, estrogen receptors, oxidative stress, apoptosis, inflammation, neurodegenerative processes, and muscle cell differentiation and contractility. Due to heterogeneity in the studies (e.g., in examined tissues), the precise contribution of the associated genes and proteins in relation to SUI pathophysiology remained unclear. Future research should focus on possible contributors to these alterations.

Effects of extracorporeal magnetic stimulation on urinary incontinence: A systematic review and meta-analysis

AIMS

To examine the effectiveness of extracorporeal magnetic stimulation for treatment of stress urinary incontinence.

DESIGN

Systematic review and meta-analysis.

DATA RESOURCES

Four electronic databases from inception to 18 May 2019.

REVIEW METHODS

Two authors independently performed the search, assessed the methodological quality, and extracted data. The final studies included in the analysis were selected after reaching consensus with the third author.

RESULTS

A total of 20 studies were included in the systematic review and 12 of these in the meta-analysis. Quality assessment indicated that only 8 of 17 randomized controlled trials had low risk in overall risk of bias, whereas all controlled trials had serious risk of bias. The weighted mean effect size of magnetic stimulation on quality of life, number of leakages, pad test outcomes, and number of incontinence events was 1.045 (95% CI: 0.409-1.681), -0.411 (95% CI: 0.178-0.643), -0.290 (95% CI: 0.025-0.556), and -0.747 (95% CI: -1.122 to -0.372), respectively. Subgroup analysis revealed a significant difference in the type of quality of life measurement used. Sensitivity analyses revealed that a high degree of heterogeneity persisted even after omitting studies individually.

CONCLUSIONS

Extracorporeal magnetic stimulation may be effective in treating urinary incontinence and improving quality of life without major safety concerns. However, because of a high degree of heterogeneity among studies, inferences from the results must be made with caution.

IMPACT

We recommend that clinical nurses apply extracorporeal magnetic stimulation to treat stress urinary incontinence among female patients and encourage researchers to conduct further qualitative and quantitative studies to develop consistent content and dosage for the intervention.

STUDY REGISTRATION

The review protocol was registered a priori and published online in the PROSPERO database of systematic reviews (www.crd.york.ac.uk/Prospero with the registration number #CRD42019138835).

Expression of ArfGAP3 in Vaginal Anterior Wall of Patients With Pelvic Floor Organ Prolapse in Pelvic Organ Prolapse and Non-Pelvic Organ Prolapse Patients

The purpose of this study was to study the expression of adenosine diphosphate ribosylation factor GTPase-activating protein 3 (ArfGAP3) in the anterior vaginal wall of patients with pelvic organ prolapse (POP).

Effect of different electrical stimulation protocols for pelvic floor rehabilitation of postpartum women with extremely weak muscle strength: Randomized control trial

BACKGROUND

Pregnancy is one of the main risk factor of pelvic floor muscle dysfunction. Postpartum women with extremely weak muscle strength have difficulty to do voluntary pelvic floor muscle training. This study aims to evaluate the effects of different protocols of electrical stimulation in the treatment of postpartum women with extremely weak muscle strength.

METHODS

A total of 67 women were randomized into 2 groups: group A received transvaginal electrical stimulation (TVES) for 5 times, and group B received TVES for 3 times with electromyogram (EMG)-triggered neuromuscular stimulation twice. Subjects were evaluated before and after treatment. Pelvic muscle strength was measured by both digital vaginal palpation and EMG variables, and quality of life was investigated by 4 kinds of pelvic floor disease-related questionnaires.

RESULTS

According to the intention-to-treat principle, compared with baseline, in group A, EMG of contractile amplitude of endurance phase was significantly elevated (P = .03), variation of contractile amplitude in tonic phase was more stable after treatment (P = .004), and EMG of mean value of final rest was significantly elevated after treatment (P = .047). After 5 times treatments, the incidence of correct pelvic floor muscle contraction in group A was significantly elevated (P = .045). No significant difference of muscle strength test by digital vaginal palpation was detected between the 2 groups, so did questionnaires.

CONCLUSION

For postpartum women with extremely weak muscle strength, TVES for 5 times might be more benefit for control ability of pelvic muscle contractions and elevating muscle strength even in short-time treatment.

Electrical stimulation for neuroregeneration in urology: a new therapeutic paradigm

PURPOSE OF REVIEW

The present review highlights regenerative electrical stimulation (RES) as potential future treatment options for patients with nerve injuries leading to urological dysfunction, such as urinary incontinence, voiding dysfunction or erectile dysfunction. Additionally, it will highlight the mechanism of nerve injury and regeneration as well as similarities and differences between RES and current electrical stimulation treatments in urology, functional electrical stimulation (FES) and neuromodulation.

RECENT FINDINGS

It has been demonstrated that RES upregulates brain-derived neurotrophic factor (BDNF) and its receptor to facilitate neuroregeneration, facilitating accurate reinnervation of muscles by motoneurons. Further, RES upregulates growth factors in glial cells. Within the past 2 years, RES of the pudendal nerve upregulated BDNF in Onuf's nucleus, the cell bodies of motoneurons that course through the pudendal nerve and accelerated functional recovery in an animal model of stress urinary incontinence. Additionally, electrical stimulation of the vaginal tissue in an animal model of stress urinary incontinence accelerated functional recovery.

SUMMARY

RES has great potential but future research is needed to expand the potential beneficial effects of RES in the field of urology.

Which pelvic floor muscle functions are associated with improved subjective and objective symptoms after 8 weeks of surface electrical stimulation in women with stress urinary incontinence?

OBJECTIVE

Stress urinary incontinence (SUI) is defined as involuntary urine loss during effort, sneezing, or coughing. We investigated which pelvic floor muscle (PFM) functions (muscle strength, power, and endurance) are associated with improvement in subjective and objective symptoms after 8 weeks of surface electrical stimulation (SES) training. This study was performed to determine the effects of SES in the seated position on PFM functions and subjective and objective symptoms, and to identify predictors of improved subjective and objective symptoms after 8 weeks of SES training via secondary analysis of females with SUI.

STUDY DESIGN

The study was performed between August 2018 and December 2018. Patients with SUI were randomized into an SES group (n = 17) and a control group (n = 17). Both groups were assessed pre-intervention and after 8 weeks of intervention. The outcome measures were PFM functions (strength, power, and endurance) as measured via perineometry, the score on the urogenital distress inventory-6 (UDI-6), and the ultra-short perineal pad test result.

RESULTS

Significant differences in all PFM functions, the UDI-6 score, and the pad weight were evident both between the groups (SES vs. control group) and within the groups (pre-SES vs. post-SES). On regression of factors predicting relative changes in subjective and objective symptoms, the relative change in PFM power accounted for 15 and 13 % of the variance in the UDI-6 score (P < 0.05) and pad weight (P < 0.05), respectively.

CONCLUSIONS

SES in a seated position improved both subjective and objective symptoms in females with SUI. PFM power, the UDI-6 score, and the pad weight test result should be considered when developing intervention guidelines to improve the subjective and objective symptoms of females with SUI.

Pelvic Floor Muscle Parameters Affect Sexual Function After 8 Weeks of Transcutaneous Electrical Stimulation in Women with Stress Urinary Incontinence

INTRODUCTION

Stress urinary incontinence (SUI) is often associated with female sexual dysfunction. We investigated which pelvic floor muscle (PFM) parameters (strength, power, and endurance) are associated with improvement of sexual function after 8 weeks of transcutaneous electrical stimulation (TES) training.

AIM

This study was performed to determine the effects of TES in the seated position on PFM parameters and female sexual function and to identify correlation between improved PFM parameters and sexual function after 8 weeks of TES training in women with SUI.

METHODS

The present study was performed between August 2018 and November 2018 in women with SUI who were randomized into a TES group (n = 17) or a control group (n = 17). One subject in each of the TES and control groups ultimately withdrew during the intervention due to a lack of time. Both groups were measured at baseline and after 8 weeks of intervention.

MAIN OUTCOME MEASURE

As outcome measures, PFM parameters (strength, power, and endurance) and female sexual function were assessed using a perineometer and the Female Sexual Function Index (FSFI), respectively.

RESULTS

The final study population consisted of 32 women with SUI. There were significant differences in PFM strength, power, and endurance and FSFI domain scores (desire, arousal, orgasm, satisfaction, and total score) in both between-group analyses (TES vs control group) and within-group analyses (pre-TES vs post-TSE). Change in PFM endurance had the highest association with change in total FSFI total score (r = 0.437; P = .006), and change in PFM power had the highest association with change in FSFI satisfaction (r = 0.420; P = .008).

CONCLUSION

TES in a seated position showed a beneficial effect on sexual function in females with SUI. Consideration of PFM parameters associated with FSFI domain scores may be important when developing intervention guidelines to improve female sexual function. Hwang UJ, Lee MS, Jung SH, et al. Pelvic Floor Muscle Parameters Affect Sexual Function After 8 Weeks of Transcutaneous Electrical Stimulation in Women with Stress Urinary Incontinence. Sex Med 2019;7:505-513.

Traditional Biofeedback vs. Pelvic Floor Physical Therapy-Is One Clearly Superior?

PURPOSE OF REVIEW

Pelvic floor physical therapy is a worldwide accepted therapy that has been exclusively used to manage many pelvic floor disorders in adults and children. The aim of this review is to suggest to clinicians an updated understanding of this therapeutic approach in management of children with non-neuropathic voiding dysfunction.

RECENT FINDINGS

Today, pelvic floor muscle training through biofeedback is widely used as a part of a voiding retraining program aiming to help children with voiding dysfunction which is caused by pelvic floor overactivity. Biofeedback on its own, without a pelvic floor training component, is not an effective treatment. Biofeedback is an adjunct to the pelvic floor training. In the current review, we develop the role of pelvic floor physical therapy in management of children with non-neuropathic voiding dysfunction and compare it with biofeedback therapy alone.

Magnetic stimulation for female patients with stress urinary incontinence, a meta-analysis of studies with short-term follow-up

BACKGROUND

To determine the efficacy of magnetic stimulation (MS) in female patients with stress urinary incontinence (SUI) by performing a meta-analysis on peer-reviewed randomized controlled trails (RCTs).

METHODS

PubMed, Embase, and Cochrane library were retrieved for any peer-reviewed original articles in English. Databases were searched up to July 2018. Included studies investigated effects of MS on SUI. The data were analyzed by review manager 5.3 software (Cochrane Collaboration, Oxford, UK).

RESULTS

A total of 4 studies involving 232 patients were identified and included in present meta-analysis. Compared with the sham stimulation, the MS group had statistically significantly fewer leaks/3 days (MD = -1.42; 95%CI: -2.42 to -0.59; P = .007), less urine loss on pad test (g.)/24 h (MD = -4.99; 95%CI: -8.46 to -1.53; P = .005), higher QoL scores (MD = 0.42; 95%CI: 0.02-0.82; P = .009), and lower ICIQ scores (MD = -4.60; 95%CI: -5.02 to -4.19; P < .001). MS presented higher cure or improvement rate, with a statistically significant improvement in UDI and IIQ-SF scores compared to sham stimulation. No MS-related adverse effects were reported in study.

CONCLUSION

MS leads to an improvement in SUI without any reported safety concerns and an improvement in patient quality of life. The long-term outcome of this technique remains unclear and is the subject of ongoing research.

Electrical Stimulation Activates Fibroblasts through the Elevation of Intracellular Free Ca2+: Potential Mechanism of Pelvic Electrical Stimulation Therapy

Ca²⁺ is an important ion in response to electrical stimulation (ES) and acts as second messenger in the regulation of various physiological processes. Pelvic floor electrical stimulation (PES) is a low-voltage clinical application, available for urinary incontinence (UI) treatment. Fibroblasts, as the main cellular component of vaginal wall and pelvic ligament, play an important role in the maintenance of pelvic health. We studied the effect of ES on fibroblasts in this study. ES was conducted with electrotaxis chambers on L929 fibroblast and the ES parameter was 100 mV/mm×2h. The results showed that ES increased intracellular Ca²⁺ concentration, promoted the expression of PCNA, CyclinB1, and CyclinD1, and increased the proportion of cells in S and G2 phages. After ES, fibroblasts get activated and proliferated. Besides, BAPTA-AM, a membrane permeated chelator for intracellular free Ca²⁺, partially inhibited the effect of ES on fibroblasts activation and proliferation promotion. Furthermore, we elucidated that Ca²⁺, as a second messenger and upstream signal for Smads and Akt signaling, regulated ES-induced nuclear translocation of smad2/3, phosphorylation of smad2/3, Akt, and GSK3β. Finally, we validated the effect of ES on PES mouse model. The results indicated that PES promoted the activation and proliferation of fibroblasts in vivo. In conclusion, we verify that ES can elevate the concentration of intracellular Ca²⁺ and activate its downstream signaling and then promote the activation of fibroblasts, which may be one of the mechanisms of PES therapy.

Effect of integrin β1 in the treatment of stress urinary incontinence by electrical stimulation

The aim of the present study was to investigate the protective effect of integrin β1 in the treatment of stress urinary incontinence (SUI) by electrical stimulation, and the underlying mechanisms by which electrical stimulation regulates the collagen metabolism of female vaginal wall fibroblasts (FVWFs). FVWFs obtained from the vaginal wall tissue of patients with (Ingelman-Sundberg scale; grade II, n=8; grade III, n=10) or without (n=8) SUI during gynecological operations were isolated by enzymatic digestion and subsequently identified by immunocytochemistry. Following this, cultured FVWFs were treated with an inhibitor of integrin β1, recombinant human integrin β1 and electrical stimulation (100 mv/mm, 2 h, 20 Hz), followed by total mRNA and protein extraction. mRNA and protein expression levels of integrin β1, transforming growth factor (TGF)-β1 and collagen (COL) I and III in FVWFs were quantified by reverse transcription-quantitative PCR (RT-qPCR) and western blot analysis respectively. Integrin β1, TGF-β1 and COL I and III expression levels were decreased in patients with SUI compared with healthy controls, and the grade III group had lower levels than the grade II group. Following electrical stimulation treatment, the expression levels of TGF-β1, COL I and III were enhanced in the grade II group, but not in the grade III group. Nevertheless, the inhibitor of integrin β1 reduced the protective effect of electrical stimulation in the grade II group. In addition, electrical stimulation combined with recombinant human integrin β1 could also protect cells from SUI in the grade III group. The present study provides evidence for the increased degradation of the extracellular matrix and integrin β1 in the vaginal wall tissues of patients with SUI, and the protective effect of electrical stimulation against SUI via integrin β1. These results provide a novel mechanism for the treatment of SUI using electrical stimulation.

Pelvic floor electrical stimulation and muscles training: a combined rehabilitative approach for management of non-neuropathic urinary incontinence in children

PURPOSE

To assess the efficacy of combined transcutaneous interferential (IF) electrical stimulation and pelvic floor muscle training through biofeedback on non-neuropathic urinary incontinence in children.

METHODS

This prospective study comprised of 46 anatomically and neurologically normal children (9 boys, 37 girls; mean age of 8.4 ± 2.2 years old) with non-neuropathic urinary incontinence. All children were evaluated by kidney and bladder ultrasounds, uroflowmetry with electromyography (EMG), a complete voiding diary and a dysfunctional voiding scoring questionnaire at the baseline. Children were randomly allocated into two treatment groups including group A (n = 23) who underwent biofeedback therapy in addition to IF electrical stimulation and group B (n = 23) who received only biofeedback therapy. Re-evaluation was performed 6 months and one year after completion of the treatment sessions.

RESULTS

Improvement of non-neuropathic urinary incontinence was significantly higher in group A in comparison to group B at two follow ups (P < 0.05). Daytime incontinence was improved in 19/23(82%) and 13/23(56.5%) of children in groups A and B respectively after the treatment (P < 0.01). There was no significant difference in uroflowmetry measures between two groups after the treatment.

CONCLUSIONS

Combination of biofeedback therapy and transcutaneous IF electrical stimulation is a potential effective modality in treating non-neuropathic urinary incontinence in children.

LEVEL OF EVIDENCE

Type of study: Treatment study. Level I: Randomized controlled trials with adequate statistical power to detect differences (narrow confidence intervals) and follow up >80%.

Electrical stimulation activates calpain 2 and subsequently upregulates collagens via the integrin β1/TGF-β1 signaling pathway

Stress urinary incontinence (SUI) is a public health issue attributed to weakened pelvic supporting tissues. Electrical stimulation (ES) is one of the first-line conservative treatments for SUI. However, the underlying mechanism of ES in the treatment of SUI is not clear. Here, we show that ES suppresses cell apoptosis and upregulates collagen expression by functioning as a cell growth inducer to activate the calpain 2/talin 1/integrin β1/transforming growth factor (TGF)-β1 axis. Specifically, ES promoted Ca²⁺ to flow into the cytoplasm through the calcium channel, Cav 3.2, thereby activating calpain 2. Then, the activated calpain 2 cleaved talin 1, which induced the activation of integrin β1 and upregulated the TGF-β1-mediated transcription of collagen I and III. Notably, blocking Cav 3.2 suppressed calcium influx and inhibited the activation of downstream proteins. Furthermore, the knockdown of calpain 2 resulted in the reduction of cleaved talin 1, and the shRNA-integrin β1 treatment downregulated the level of activated integrin β1 and the expression of TGF-β1-induced collagen I and III. An association of the ES-modulated collagen I and III upregulation with the therapeutic effect of the ES-Ca²⁺/calpain 2/talin 1/integrin β1/TGF-β1 axis was demonstrated in mouse fibroblast and mouse SUI models established through vaginal distension (VD). This outcome provides insight into clinical diagnosis and treatment.

Electrical stimulation enhances neuronal cell activity mediated by Schwann cell derived exosomes

Electrical stimulation (ES) therapy has good effects in patients with nervous system injury-related diseases. ES promotes nerve cell regeneration and stimulates Schwann cells to express neurotrophic factors. The incidence of stress urinary incontinence (SUI) among elderly people is increasing. Some studies suggest that damage to the pudendal nerve is closely related to the pathogenesis of SUI. It has also been found that pelvic ES can reduce SUI symptoms in a rat model of SUI caused by pudendal nerve injury. Clinically, pelvic floor electrical stimulation is effective in patients with mild to moderate SUI. These studies indicate that ES may ameliorate damage to the pudendal nerve and thus achieve the goal of SUI treatment, although the mechanism of action of this treatment remains unclear. Therefore, the purpose of the present study was to clarify the relationships among ES, neural cells and Schwann cells at the cellular level. We applied ES to nerve cells at 100 mV/mm or 200 mV/mm for 0, 0.5, 1, or 2 h to investigate changes in nerve cell activity. We then co-cultured the nerve cells with Schwann cells to explore the influence of single-culture and co-culture conditions on the nerve cells. Compared to non-ES, ES of the nerve cells increased their activity. Compared to those in single culture, co-cultured nerve cells exhibited an additional increase in activity. We also found that Schwann cell derived exosomes could promote the activity of nerve cells, with glutamate and calcium ions playing a potential role in this process. These results suggest that the mutual regulation of neural cells and Schwann cells plays an important role in the process by which ES ameliorates neurological function, which may provide a basis for subsequent studies.

Potential Usefulness of Losartan as an Antifibrotic Agent and Adjunct to Platelet-Rich Plasma Therapy to Improve Muscle Healing and Cartilage Repair and Prevent Adhesion Formation

Postoperative tissue fibrosis represents a major complication in orthopedics. Transforming growth factor beta 1 is a key molecule in the development of postoperative fibrosis. High concentrations of transforming growth factor beta 1 have also been implicated in various diseases. Agents that counteract the actions of transforming growth factor beta 1 have been investigated as potential antifibrotic medications and as adjunct treatment to platelet-rich plasma injections (increased amounts of transforming growth factor beta 1) to improve their effectiveness and/or safety profile. Losartan blocks transforming growth factor beta 1 action and has attracted special interest in orthopedic research that focuses on how to reduce the risk of postoperative fibrosis. [Orthopedics. 2018; 41(5):e591-e597.].

miR-93‑mediated collagen expression in stress urinary incontinence via calpain-2

The aim of the present study was to investigate the expression and mechanism of microRNA (miR)‑93 in collagen expression in stress urinary incontinence (SUI). Vaginal tissue, primary fibroblasts and SUI primary fibroblasts were obtained to detect the expression of miR‑93, interstitial collagenase (MMP1), collagen I and calpain‑2. Reverse transcription‑quantitative polymerase chain reaction analysis was performed to detect the levels of miR‑93 and MMP1. Western blotting was used to evaluate the protein levels of calpain‑2, MMP1 and collagen I. MMP1 and hydroxyproline levels in the supernatant were measured by ELISA. The association between miR‑93 and calpain‑2 was investigated by luciferase reporter assays. The expression of miR‑93 and collagen I was significantly downregulated in the SUI group, while the expression of calpain‑2 and MMP1 was significantly upregulated. ELISA analysis demonstrated that the MMP1 level increased and the hydroxyproline level decreased in the SUI group. Additionally, calpain‑2 was identified to be a target of miR‑93, and miR‑93 was able to negatively regulate the expression of calpain‑2. Restoration of calpain‑2 in miR‑93‑overexpresseing SUI primary fibroblasts reversed the alteration in hydroxyproline expression, indicating that calpain‑2 was negatively associated with collagen expression. The results of the present study suggested that miR‑93 regulated MMP1 and collagen I expression in fibroblasts via calpain‑2. miR‑93 mediated collagen expression in stress urinary incontinence via calpain‑2.