Autologous myoblasts and fibroblasts versus collagen for treatment of stress urinary incontinence in women: a randomised controlled trial

Neobladder "Function": Tips and Tricks for Surgery and Postoperative Management

Orthotopic neobladder (ONB) reconstruction is a continent urinary diversion procedure increasingly used in patients with muscle-invasive bladder cancer following radical cystectomy (RC). It represents a valid alternative to the ileal duct in suitable patients who do not prefer a stoma and are motivated to undergo adequate training of the neobladder. Careful patient selection, taking into account the absolute and relative contraindications for ONB as well as an adequate recovery protocol after surgery are integral to the success of this procedure and the oncological and functional outcomes. The objective of this review is to summarize the current data on RC with ONB in terms of patient selection, preoperative preparation, surgical techniques and functional (continence and sexual activity) and oncological outcomes, with particular attention to the management of complications and the impact on quality of life (QoL).

Treatment of Stress Urinary Incontinence with Muscle Stem Cells and Stem Cell Components: Chances, Challenges and Future Prospects

Urinary incontinence (UI) is a major problem in health care and more than 400 million people worldwide suffer from involuntary loss of urine. With an increase in the aging population, UI is likely to become even more prominent over the next decades and the economic burden is substantial. Among the different subtypes of UI, stress urinary incontinence (SUI) is the most prevalent and focus of this review. The main underlying causes for SUI are pregnancy and childbirth, accidents with direct trauma to the pelvis or medical treatments that affect the pelvic floor, such as surgery or irradiation. Conservative approaches for the treatment of SUI are pelvic physiotherapy, behavioral and lifestyle changes, and the use of pessaries. Current surgical treatment options include slings, colposuspensions, bulking agents and artificial urinary sphincters. These treatments have limitations with effectiveness and bear the risk of long-term side effects. Furthermore, surgical options do not treat the underlying pathophysiological causes of SUI. Thus, there is an urgent need for alternative treatments, which are effective, minimally invasive and have only a limited risk for adverse effects. Regenerative medicine is an emerging field, focusing on the repair, replacement or regeneration of human tissues and organs using precursor cells and their components. This article critically reviews recent advances in the therapeutic strategies for the management of SUI and outlines future possibilities and challenges.

Small extracellular vesicles secreted by vaginal fibroblasts exert inhibitory effect in female stress urinary incontinence through regulating the function of fibroblasts

Stress urinary incontinence (SUI) is a common condition in women and associated with extra-cellular matrix (ECM) reconstruction, which is mainly regulated by fibroblasts. However, the underlying mechanism remains obscure. Small extracellular vesicles (sEVs) play fundamental biological roles in various cellular functions. Some studies suggested that the sEVs were involved in the metabolism of ECM and the function of fibroblasts. The purpose of our study was to investigate the effect of sEVs secreted by vaginal fibroblasts on the pathogenesis of SUI. We showed that the fibroblasts of female anterior vaginal wall secreted sEVs. Moreover, fibroblasts of females with SUI had significantly elevated secretion of sEVs. The collagen contents, proliferation and migration capacity of fibroblasts were decreased when fibroblasts were co-cultured with fibroblasts-derived sEVs (fibroblast-sEVs) from SUI patients. Proteomic analysis revealed that fibroblast-sEVs contained various differentially expressed proteins including TIMP2, TGF-β and ABCC4, which were involved in signaling pathways of fibroblasts regulation. Therefore, we suggested that fibroblast-sEVs contributed to the pathogenesis of SUI through various proteins including TIMP2, TGF-β and ABCC4.

Biomedical applications of muscle-derived stem cells: from bench to bedside

INTRODUCTION

Skeletal muscle-derived stem cells (Sk-MDSCs) are considered promising sources of adult stem cell therapy. Skeletal muscle comprises approximately 40-50% of the total body mass with marked potential for postnatal adaptive response, such as muscle hypertrophy, hyperplasia, atrophy, and regenerative capacity. This strongly suggests that skeletal muscle contains various stem/progenitor cells related to muscle-nerve-vascular tissues, which would support the above postnatal events even in adulthood.

AREA COVERED

The focus of this review is the therapeutic potential of the Sk-MDSCs as an adult stem cell autograft. For this purpose, the validity of cell isolation and purification, tissue reconstitution capacity in vivo after transplantation, comparison of the results of basic mouse and preclinical human studies, potential problematic and beneficial aspects, and effective usage have been discussed following the history of clinical applications.

EXPERT OPINION

Although the clinical application of Sk-MDSCs began as a therapy for the systemic disease of Duchenne muscular dystrophy, here, through the unique local injection method, therapy for severely damaged peripheral nerves, particularly the long-gap nerve transection, has been introduced. The beneficial aspects of the use of Sk-MDSCs as the source of local tissue transplantation therapy have also been discussed.

Stem cell in urology-are we at the cusp of a new era?

Stem cell therapy can potentially disrupt conventional medicine as we practice it today. Stem cells can self-renew and differentiate and by this, repair and in certain conditions regenerate damaged tissue. In the past two decades, there has been significant research into its value in several chronic urological conditions for which conventional therapy is unsatisfactory. Stem cell therapy has been tried on animal models of bladder dysfunction, stress urinary incontinence (SUI), erectile dysfunction and urethral injury and certain preclinical studies have had very encouraging results. Yet despite this explosion of knowledge about the nature and value of stem cells, translation of research into the clinical domain has been slow. In addition, lack of regulation of stem cell therapy has resulted in indiscriminate, unscientific administration of stem cell therapy to patients. This review looks into the advances in the use of stem cells in urological practice, the recent regulatory guidelines that have been introduced and what the future holds for this exciting branch.

Cell Therapy Clinical Trials for Stress Urinary Incontinence: Current Status and Perspectives

Stress urinary incontinence (SUI) affects 200 million people worldwide. Standard therapies often provide symptomatic relief, but without targeting the underlying etiology, and show tremendous patient-to-patient variability, limited success and complications associated with the procedures. We review in this article the latest clinical trials performed to treat SUI using cell-based therapies. These therapies, despite typically including only a small number of patients and short term evaluation of results, have proven to be feasible and safe. However, there is not yet a consensus for the best cell source to be used to treat SUI and not all patients may be suitable for these therapies. Therefore, more clinical trials should be promoted recruiting large number of patients and evaluating long term results.

Urethral injection therapy for urinary incontinence in women

BACKGROUND

Urinary incontinence imposes a significant health and economic burden to society. Periurethral or transurethral injection of bulking agents is a minimally invasive surgical procedure used as one the surgical treatments of stress urinary incontinence (SUI) in adult women.

OBJECTIVES

To assess the effects of periurethral or transurethral injection therapy on the cure or improvement of urinary incontinence in women.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Trials Register (searched 8 November 2010) and the reference lists of relevant articles.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of treatment for urinary incontinence in which at least one management arm involved periurethral or transurethral injection therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed methodological quality of each study using explicit criteria. Data extraction was undertaken independently and clarification concerning possible unreported data sought directly from the investigators.

MAIN RESULTS

Excluding duplicate reports, we identified 14 trials (excluding one that was subsequently withdrawn from publication and not included in this analysis) including 2004 women that met the inclusion criteria. The limited data available were not suitable for meta-analysis because they all came from separate trials. Trials were small and generally of moderate quality.One trial of 45 women that compared injection therapy with conservative treatment showed early benefit for the injectable therapy with respect to continence grade (risk ratio (RR) 0.70, 95% confidence interval (CI) 0.52 to 0.94) and quality of life (mean difference (MD) 0.54, 95% CI 0.16 to 0.92). Another trial, comparing Injection of autologous fat with placebo, terminated early because of safety concerns. Two trials that compared injection with surgical management found significantly better objective cure in the surgical group (RR 4.77, 95% CI 1.96 to 11.64; and RR 1.69, 95% CI 1.02 to 2.79), although the latter trial data did not reach statistical significance if an intention-to-treat analysis was used.Eight trials compared different agents and all results had wide confidence intervals. Silicone particles, calcium hydroxylapatite, ethylene vinyl alcohol, carbon spheres and dextranomer hyaluronic acid combination gave improvements which were not shown to be more or less efficacious than collagen. Dextranomer hyaluronic acid compound treated patients appeared to have significantly higher rates of injection site complications (16% with the hyaluronic acid compound versus none with collagen; RR 37.78, 95% CI 2.34 to 610.12) and this product has now been withdrawn from the market.A comparison of periurethral and transurethral methods of injection found similar outcomes but a higher (though not statistically significant) rate of early complications in the periurethral group. One trial of 30 women showed a weak (but not clinically significant) advantage for patient satisfaction (data not suitable for analysis in RevMan) after mid-urethral injection in comparison to bladder neck injection but with no demonstrable difference in continence levels.

AUTHORS' CONCLUSIONS

The available evidence base remains insufficient to guide practice. In addition, the finding that placebo saline injection was followed by a similar symptomatic improvement to bulking agent injection raises questions about the mechanism of any beneficial effects. One small trial comparing silicone particles with pelvic floor muscle training was suggestive of benefit at three months but it is not known if this was sustained, and the treatment was associated with high levels of postoperative retention and dysuria. Greater symptomatic improvement was observed with surgical treatments, though the advantages need to be set against likely higher risks. No clear-cut conclusions could be drawn from trials comparing alternative agents, although dextranomer hyaluronic acid was associated with more local side effects and is no longer commercially available for this indication. There is insufficient evidence to show superiority of mid-urethral or bladder neck injection. The single trial of autologous fat provides a reminder that periurethral injections can occasionally cause serious side effects. Also, a Brief Economic Commentary (BEC) identified three studies suggesting that urethral bulking agent might be more cost-effective compared with retropubic mid-urethral slings, transobturator or traditional sling procedure when used as an initial treatment in women without hypermobility or as a follow-up to surgery failure provided injection is kept minimal. However, urethral bulking agent might not be cost-effective when compared with traditional sling as an initial treatment of SUI when a patient is followed up for a longer period (15 months post-surgery).

Biomaterial Scaffolds for Reproductive Tissue Engineering

The reproductive system usually involves gamete producing gonads, a series of specialized ducts, accessory glands and the external genitalia. Despite there are many traditional methods such as hormonal and surgical approaches, at present no effective treatments exist to help patients suffering from serious diseases of reproductive system, including congenital and acquired abnormalities, malignant tumor, traumatic, infectious etiologies, inflammation and iatrogenic injuries. Tissue engineering holds promise for reproductive medicine through the development of biological alternative. Till now, a diverse range of biomaterials have been utilized as suitable substrates to match both the mechanical and biological context of reproductive tissues. The current review will focus mainly on the applications of biomaterial scaffolds and their major achievements in each region of reproductive systems.

Application of Tissue Engineering to Pelvic Organ Prolapse and Stress Urinary Incontinence

Synthetic or biological materials can be used for the surgical repair of pelvic organ prolapse (POP) or stress urinary incontinence (SUI). While non-degradable synthetic mesh has a low failure rate, it is prone to complications such as infection and erosion, particularly in the urological/gynecological setting when subject to chronic influences of gravity and intermittent, repetitive strain. Biological materials have lower complication rates, although allografts and xenografts have a high risk of failure and the theoretical risk of infection. Autografts are used successfully for the treatment of SUI and are not associated with erosion; however, can lead to morbidity at the donor site. Tissue engineering has thus become the focus of interest in recent years as researchers seek an ideal tissue remodeling material for urogynecological repair. Herein, we review the directions of current and future research in this exciting field. Electrospun poly-L-lactic acid (PLA) and porcine small intestine submucosa (SIS) are two promising scaffold material candidates. Adipose-derived stem cells (ADSCs) appear to be a suitable cell type for scaffold seeding, and cells grown on scaffolds when subjected to repetitive biaxial strain show more appropriate biomechanical properties for clinical implantation. After implantation, an appropriate level of acute inflammation is important to precipitate moderate fibrosis and encourage tissue strength. New research directions include the use of bioactive materials containing compounds that may help facilitate integration of the new tissue. More research with longer follow-up is needed to ascertain the most successful and safe methods and materials for pelvic organ repair and SUI treatment.

Adipose-Derived Regenerative Cell Injection Therapy for Postprostatectomy Incontinence: A Phase I Clinical Study

PURPOSE

We report our initial experience with transurethral injection of autologous adipose-derived regenerative cells (ADRCs) for the treatment of urinary incontinence after radical prostatectomy.

MATERIALS AND METHODS

After providing written informed consent, six men with persistent urinary incontinence after radical prostatectomy were enrolled in the study. Under general anesthesia, about 50 mL of adipose tissue was obtained from the patients by liposuction. ADRCs were obtained by separation with centrifugation using the Celution cell-processing device. A mixture of ADRCs and adipose tissue were transurethrally injected into the submucosal space of the membranous urethra. Functional and anatomical improvement was assessed using a 24-h pad test, validated patient questionnaire, urethral pressure profile, and magnetic resonance imaging (MRI) during 12-week follow-up.

RESULTS

Urine leakage volume was improved with time in all patients in the 24-h pad test, with the exemption of temporal deterioration at the first 2 weeks post-injection in 2 patients. Subjective symptoms and quality of life assessed on the basis of questionnaire results showed similar improvement. The mean maximum urethral closing pressure increased from 44.0 to 63.5 cm H₂O at 12 weeks after injection. MRI showed an increase in functional urethral length (from 6.1 to 8.3 mm) between the lower rim of the pubic bone and the bladder neck. Adverse events, such as pelvic pain, inflammation, or de novo urgency, were not observed in any case during follow-up.

CONCLUSION

This study demonstrated that transurethral injection of autologous ADRCs can be a safe and effective treatment modality for postprostatectomy incontinence.

Stem Cell Therapy for Male Urinary Incontinence

INTRODUCTION

Among the medical and surgical options which have been proposed in the last years for the management of male stress urinary incontinence (SUI), stem cell therapy represents a new frontier treatment. The aim of this paper is to update the current status of stem cell therapy in animal and human studies for the management of iatrogenic male SUI.

MATERIAL AND METHODS

A PubMed review of the literature on stem cell therapy for the treatment of male SUI was performed.

RESULTS

Regarding animal studies, bone marrow-, muscle- and adipose-derived stem cells have been widely studied, showing regeneration of the urethral sphincter and recovery of the damaged pelvic nerves. With regard to human studies, only four papers are available in the literature using muscle- and adipose-derived stem cells which reported a significant improvement in sphincteric function and incontinence with no severe side effects.

CONCLUSIONS

In spite of these promising results, further studies are needed with longer follow-ups and larger numbers of patients in order to clarify the potential role of stem cell therapy for the treatment of male SUI.

Prospective regenerative medicine therapies for obstetric trauma-induced fecal incontinence

Fecal incontinence is a major public health issue that has yet to be adequately addressed. Obstetric trauma and injury to the anal sphincter muscles are the most common cause of fecal incontinence. New therapies are emerging aimed at repair or regeneration of sphincter muscle and restoration of continence. While regenerative medicine offers an attractive option for fecal incontinence there are currently no validated techniques using this approach. Although many challenges are yet to be resolved, the advent of regenerative medicine is likely to offer disruptive technologies to treat and possibly prevent the onset of this devastating condition. This article provides a review on regenerative medicine approaches for treating fecal incontinence and a critique of the current landscape in this area.

Prospects of stem cell treatment in benign urological diseases

Stem cells (SCs) are undifferentiated cells that are capable of self-renewal and differentiation and that therefore contribute to the renewal and repair of tissues. Their capacity for division, differentiation, and tissue regeneration is highly dependent on the surrounding environment. Several preclinical and clinical studies have utilized SCs in urological disorders. In this article, we review the current status of SC use in benign urological diseases (erectile dysfunction, Peyronie disease, infertility, and urinary incontinence), and we summarize the results of the preclinical and clinical trials that have been conducted.

The future of research in female pelvic medicine

Female pelvic medicine and reconstructive surgery (FPMRS) was recently recognized as a subspecialty by the American Board of Medical Specialties (ABMS). FPMRS treats female pelvic disorders (FPD) including pelvic organ prolapse (POP), urinary incontinence (UI), fecal incontinence (FI), lower urinary tract symptoms (LUTS), lower urinary tract infections (UTI), pelvic pain, and female sexual dysfunction (FSD). These conditions affect large numbers of individuals, resulting in significant patient, societal, medical, and financial burdens. Given that treatments utilize both medical and surgical approaches, areas of research in FPD necessarily cover a gamut of topics, ranging from mechanistically driven basic science research to randomized controlled trials. While basic science research is slow to impact clinical care, transformational changes in a field occur through basic investigations. On the other hand, clinical research yields incremental changes to clinical care. Basic research intends to change understanding whereas clinical research intends to change practice. However, the best approach is to incorporate both basic and clinical research into a translational program which makes new discoveries and effects positive changes to clinical practice. This review examines current research in FPD, with focus on translational potential, and ponders the future of FPD research. With a goal of improving the care and outcomes in patients with FPD, a strategic collaboration of stakeholders (patients, advocacy groups, physicians, researchers, professional medical associations, legislators, governmental biomedical research agencies, pharmaceutical companies, and medical device companies) is an absolute requirement in order to generate funding needed for FPD translational research.

Regeneration of degenerated urinary sphincter muscles: improved stem cell-based therapies and novel imaging technologies

Stress urinary incontinence (SUI) is a largely ousted but significant medical, social, and economic problem. Surveys suggest that nowadays approximately 10% of the male and 15% of the female population suffer from urinary incontinence at some stage in their lifetime. In women, two major etiologies contribute to SUI: degeneration of the urethral sphincter muscle controlling the closing mechanism of the bladder outflow and changes in lower pelvic organ position associated with degeneration of connective tissue or with mechanical stress, including obesity and load and tissue injury during pregnancy and delivery. In males, the reduction of the sphincter muscle function is sometimes due to surgical interventions as a consequence of prostate cancer treatment, benign prostate hyperplasia, or of neuropathical origin. Accordingly, for women and men different therapies were developed. In some cases, SUI can be treated by physical exercise, electrophysiological stimulation, and pharmacological interventions. If this fails to improve the situation, surgical interventions are required. In standard procedures, endoprostheses for mechanical support of the weakened tissue or mechanical valves for a bladder outflow control are implanted. In 20% of cases treated, repeat procedures are required as implants yield all sorts of side effects in time. Based on preclinical studies, the application of an advanced therapy medicinal product (ATMP) such as implantation of autologous cells may be a curative and long-lasting therapy for SUI. Cellular therapy could also be an option for men suffering from incontinence caused by injury of the nerves controlling the muscular sphincter system. Here we briefly report on human progenitor cells, especially on mesenchymal stromal cells (MSCs), their expansion and differentiation to smooth muscle or striated muscle cells in vitro, labeling of cells for in vivo imaging, concepts of improved, precise, yet gentle application of cells in muscle tissue, and monitoring of injected cells in situ.

Injectable treatments for female stress urinary incontinence

The use of injectable agents for the treatment of stress urinary incontinence (SUI) is an option for female patients who are unwilling to undergo surgery, or have concurrent conditions or diseases that render surgical treatment unsuitable. To be effective for SUI, an injectable agent must be nonimmunogenic, hypoallergenic, biocompatible, permanent, nonerosive, nonmigratory and painless. It must also heal with minimal fibrosis, possess a long-term bulking effect, and be easily stored and handled. Glutaraldehyde cross-linked bovine collagen (Contigen), silicone polymers (Macroplastique), Durasphere, calcium hydroxyapatite (Coaptite), polyacrylamide hydrogel (Aquamid, Bulkamid), Permacol, and stem cell therapy have been used as injectable agents. Patients must be informed that treatment with injectable agents is not as effective as surgical treatment, and that such agents might necessitate additional and repeated administrations in order to achieve the desired therapeutic effect.

Cell-based therapy for the deficient urinary sphincter

When sterile culture techniques of mammalian cells first became state of the art, there was tremendous anticipation that such cells could be eventually applied for therapeutic purposes. The discovery of adult human stem or progenitor cells further motivated scientists to pursue research in cell-based therapies. Although evidence from animal studies suggests that application of cells yields measurable benefits, in urology and many other disciplines, progenitor-cell-based therapies are not yet routinely clinically available. Stress urinary incontinence (SUI) is a condition affecting a large number of patients. The etiology of SUI includes, but is not limited to, degeneration of the urinary sphincter muscle tissue and loss of innervation, as well as anatomical and biomechanical causes. Therefore, different regimens were developed to treat SUI. However, at present, a curative functional treatment is not at hand. A progenitor-cell-based therapy that can tackle the etiology of incontinence, rather than the consequences, is a promising strategy. Therefore, several research teams have intensified their efforts to develop such a therapy for incontinence. Here, we introduce candidate stem and progenitor cells suitable for SUI treatment, show how the functional homogeneity and state of maturity of differentiated cells crucial for proper tissue integration can be assessed electrophysiologically prior to their clinical application, and discuss the trophic potential of adult mesenchymal stromal (or stem) cells in regeneration of neuronal function.

Towards a Treatment of Stress Urinary Incontinence: Application of Mesenchymal Stromal Cells for Regeneration of the Sphincter Muscle

Stress urinary incontinence is a significant social, medical, and economic problem. It is caused, at least in part, by degeneration of the sphincter muscle controlling the tightness of the urinary bladder. This muscular degeneration is characterized by a loss of muscle cells and a surplus of a fibrous connective tissue. In Western countries approximately 15% of all females and 10% of males are affected. The incidence is significantly higher among senior citizens, and more than 25% of the elderly suffer from incontinence. When other therapies, such as physical exercise, pharmacological intervention, or electrophysiological stimulation of the sphincter fail to improve the patient’s conditions, a cell-based therapy may improve the function of the sphincter muscle. Here, we briefly summarize current knowledge on stem cells suitable for therapy of urinary incontinence: mesenchymal stromal cells, urine-derived stem cells, and muscle-derived satellite cells. In addition, we report on ways to improve techniques for surgical navigation, injection of cells in the sphincter muscle, sensors for evaluation of post-treatment therapeutic outcome, and perspectives derived from recent pre-clinical studies.

Tissue engineered bulking agent with adipose-derived stem cells and silk fibroin microspheres for the treatment of intrinsic urethral sphincter deficiency

In this study we developed a tissue engineered bulking agent that consisted of adipose-derived stem cells (ADSCs) and silk fibroin microspheres to treat stress urinary incontinence caused by severe intrinsic sphincter deficiency (ISD). ISD models were established by completely transection of the bilateral pudendal nerve (PNT) and confirmed by the decreased leak-point pressure (LPP) and increased lumen area of urethra. Injection of silk fibroin microspheres could recover LPP and lumen area at 4 weeks but its efficacy disappears at 8, 12 weeks. Moreover, it was exciting to find that tissue engineered bulking agent brought long-term efficacy (at 4, 8, 12 weeks post-injection) on the recovery of LPP and lumen area. Concomitantly with the function, tissue engineered bulking agent treated group also improved the urethral sphincter structure as exhibited by better tissue regeneration. The findings showed that silk fibroin microspheres alone could work effectively in short-term, while tissue engineered bulking agent that combined silk fibroin microspheres with ADSCs exhibited promising long-term efficacy. This study developed a new strategy of tissue engineered bulking agent for future ISD therapy.

Stem cell therapy for stress urinary incontinence: a systematic review in human subjects

PURPOSE

To systematically evaluate the current evidence on the safety and efficacy of stem cell therapy (SCT) in stress urinary incontinence (SUI) to allow objective comparison with existing surgical techniques.

METHODS

Systematic literature search of Medline from years 1946-2012 using terms: "stem", "cell", "stress", "urinary", and "incontinence". Included studies presented empirical data on the treatment of SUI using SCT.

OUTCOMES

adverse events, incontinence, quality of life, urodynamic, transurethral ultrasound and urethral EMG findings.

RESULTS

Eight studies met inclusion criteria (seven observational and one randomized). Quality score: median 10.75 of 20 (range 2-12.5). Adverse events: one patient had bladder perforation and two procedures could not be completed due to pain. Temporary urinary retention and cystitis were also reported. Incontinence score: Four studies describe significant improvement. Quality of life: significant improvement in four studies. Urodynamic outcomes: four studies show significant improvement in contractility of urethral sphincter; three studies demonstrate no change in bladder capacity and significant reduction in residual volume; significant improvement in urinary flow three studies, although two found no difference; increase in leak point pressure and detrusor pressure in three studies. Urethral ultrasound: three studies found significant increases in rhabdosphincter thickness and contractility. Urethral EMG: two studies found significant increases in the EMG at rest and at contraction.

CONCLUSION

Data suggest that SC treatment for SUI is safe and effective in the short term. However, the quality and maturity of the data are limited. Robust data from better quality studies comparing this to current surgical techniques are needed.

Adult stem cells derived from skeletal muscle — biology and potential

Skeletal muscle contains at least two distinct populations of adult stem cells — satellite cells and multipotent muscle-derived stem cells. Monopotential satellite cells are located under the basal lamina of muscle fibers. They are capable of giving rise only to cells of myogenic lineage, which play an important role in the processes of muscle regeneration. Multipotent muscle-derived stem cells are considered to be predecessors of the satellite cells. Under proper conditions, both in vitro and in vivo, they undergo myogenic, cardiogenic, chondrogenic, osteogenic and adipogenic differentiation. The main purpose of the present article is to summarize current information about adult stem cells derived from skeletal muscle, and to discuss their isolation and in vitro expansion techniques, biological properties, as well as their potential for regenerative medicine.

Stem cell therapy for voiding and erectile dysfunction

Voiding dysfunction comprises a variety of disorders, including stress urinary incontinence and overactive bladder, and affects millions of men and women worldwide. Erectile dysfunction (ED) also decreases quality of life for millions of men, as well as for their partners. Advanced age and diabetes are common comorbidities that can exacerbate and negatively impact upon the development of these disorders. Therapies that target the pathophysiology of these conditions to halt progression are not currently available. However, stem cell therapy could fill this therapeutic void. Stem cells can reduce inflammation, prevent fibrosis, promote angiogenesis, recruit endogenous progenitor cells, and differentiate to replace damaged cells. Adult multipotent stem cell therapy, in particular, has shown promise in case reports and preclinical animal studies. Stem cells also have a role in urological tissue engineering for ex vivo construction of bladder wall and urethral tissue (using a patient's own cells) prior to transplantation. More recent studies have focused on bioactive factor secretion and homing of stem cells. In the future, clinicians are likely to utilize allogeneic stem cell sources, intravenous systemic delivery, and ex vivo cell enhancement to treat voiding dysfunction and ED.

Muscle-derived cells for treatment of iatrogenic sphincter damage and urinary incontinence in men

Introduction. Aim of this study was to assess the safety and efficacy of injection of autologous muscle-derived cells into the urinary sphincter for treatment of postprostatectomy urinary incontinence in men and to characterize the injected cells prior to transplantation. Methods. 222 male patients with stress urinary incontinence and sphincter damage after uroloical procedures were treated with transurethral injection of autologous muscle-derived cells. The transplanted cells were investigated after cultivation and prior to application by immunocytochemistry using different markers of myogenic differentiation. Feasibility and functionality assessment was achieved with a follow-up of at least 12 months. Results. Follow-up was at least 12 months. Of the 222 treated patients, 120 responded to therapy of whom 26 patients (12%) were continent, and 94 patients (42%) showed improvement. In 102 (46%) patients, the therapy was ineffective. Clinical improvement was observed on average 4.7 months after transplantation and continued in all improved patients. The cells injected into the sphincter were at least ~50% of myogenic origin and representative for early stages of muscle cell differentiation. Conclusions. Transurethral injection of muscle-derived cells into the damaged urethral sphincter of male patients is a safe procedure. Transplanted cells represent different phases of myogenic differentiation.

Recovery of the injured external anal sphincter after injection of local or intravenous mesenchymal stem cells

OBJECTIVES

To understand the endogenous process of wound healing after anal sphincter injury and to determine possible mechanisms by which mesenchymal stem cells (MSCs) exert their regenerative potential.

METHODS

Virginal female rats (n=204) underwent anal sphincter laceration and repair. Thereafter, animals were randomly assigned to control injection, injection with intravenous MSCs, or direct injection of MSCs into the injured sphincter. Twenty uninjured animals served as baseline controls. Sphincters were analyzed for contractile function and parameters of wound healing 24 hours, 48 hours, 7 days, and 21 days after injury.

RESULTS

Direct injection of MSCs into the injured anal sphincter resulted in improved contractile function 21 days after injury compared with controls. Although expression of both proinflammatory (cyclooxygenase-2 and interleukin-6) and anti-inflammatory (interleukin-10 and tumor necrosis factor-α-stimulated gene-6) genes were increased dramatically and transiently after injury, MSCs did not alter this response. In contrast, transforming growth factor (TFG)-β1 (an important mediator of matrix deposition by mesenchymal cells) and lysyl oxidase (an enzyme important for synthesis of collagen and elastin) expression increased dramatically at earlier time points in the direct MSC injection group compared with controls. Increased expression of TFG-β1 and lysyl oxidase in directly injected sphincters was associated with increased collagen deposition and engraftment of MSCs in the sphincter.

CONCLUSION

In this preclinical animal model, direct, but not intravenous, injection of MSCs into the injured anal sphincter at the time of repair resulted in improved contractile function of the sphincter after injury, increased matrix deposition in the external anal sphincter, and increased expression of TFG-β1 and lysyl oxidase in the acute phase after injury.

Retracted publications in the drug literature

Recent studies have suggested an increase in the number of retracted scientific publications. It is unclear how broadly the issue of misleading and fraudulent publications pertains to retractions of drug therapy studies. Therefore, we sought to determine the trends and factors associated with retracted publications in drug therapy literature. A PubMed search was conducted to identify retracted drug therapy articles published from 2000-2011. Articles were grouped according to reason for retraction, which was classified as scientific misconduct or error. Scientific misconduct was further divided into data fabrication, data falsification, questions of data veracity, unethical author conduct, and plagiarism. Error was defined as duplicate publication, scientific mistake, journal error, or unstated reasons. Additional data were extracted from the retracted articles, including type of article, funding source, author information, therapeutic area, and retraction issue. A total of 742 retractions were identified from 2000-2011 in the general biomedical literature, and 102 drug studies met our inclusion criteria. Of these, 73 articles (72%) were retracted for a reason classified as scientific misconduct, whereas 29 articles (28%) were retracted for error. Among the 73 articles classified as scientific misconduct, those classified as unethical author conduct (32 articles [44%]) and data fabrication (24 articles [33%]) constituted the majority. The median time from publication of the original article to retraction was 31 months (range 1-130). Fifty percent of retracted articles did not state a funding source, whereas pharmaceutical manufacturer funding accounted for only 13 articles (13%) analyzed. Many retractions were due to repeat offenses by a small number of authors, with nearly 40% of the retracted studies associated with two individuals. We found that a greater proportion of drug therapy articles were retracted for reasons of misconduct and fraud compared with other biomedical studies. It is important for health care practitioners to monitor the literature for retractions so that recommendations for drug therapy and patient management may be modified accordingly.

Will we ever use stem cells for the treatment of SUI? ICI-RS 2011

AIMS

To review the current state of research in the use of stem cells (SCs) for stress urinary incontinence (SUI) and assess the likelihood of this becoming a relevant treatment option.

METHODS

The peer-reviewed literature consisting of relevant clinical and animal studies on the topic of SUI was surveyed and reviewed.

RESULTS

Animal studies have demonstrated the potential utility of SCs in promoting functional recovery of the urethra after simulated childbirth injury. Research in animals suggests similar urethral recovery after injection of bone marrow derived mesenchymal SC secretions as after injection of the SCs themselves. Therefore, whether the improvements result from the injection of the SCs themselves or from their secretion of specific proteins is unclear. Early clinical trials have demonstrated the feasibility and short-term safety of injecting muscle-derived SCs into the urethra to treat SUI.

CONCLUSIONS

Larger and longer-term clinical trials are needed. Nonetheless, efficacious SC-based therapy for the treatment of SUI is practical, achievable and should be available as a treatment modality in the near future.

Management of Recurrent or Persistent Stress Urinary Incontinence after Mid-urethral Sling

The mid-urethral sling (MUS) procedure is the most common treatment modality for women with stress urinary incontinence (SUI). Although this procedure is highly successful, 5-20% of patients undergoing MUS experience persistent or recurrent SUI, regarded as surgical failure. However, little is known about methods to evaluate and manage patients who fail MUS procedures. The surgical options in these patients include bulking agent injection, shortening of pre-implanted tape, pubovaginal sling and repeat MUS. Of these secondary procedures, repeat MUS is the most widely studied, although this has been limited to small case series without long-term follow-up. Repeat MUS for prior MUS failure has shown relatively good success rates, ranging from 55 to 90%, with better outcomes obtained using the retropubic rather than the transobturator route. Persistent or recurrent SUI may also be successfully managed with less invasive techniques, such as tape shortening and periurethral injection of a bulking agent. Transurethral injection therapy for primary SUI has shown success rates of more than 65% at 1 year; however, these decreased significantly thereafter to around 30% at long-term follow-up. Since the optimal management of recurrent or persistent SUI after MUS has not yet been established, long-term, prospective, randomized trials are warranted.

Urethral injection therapy for urinary incontinence in women

BACKGROUND

Periurethral or transurethral injection of bulking agents is a minimally invasive surgical procedure used for the treatment of stress urinary incontinence in adult women.

OBJECTIVES

To assess the effects of periurethral or transurethral injection therapy on the cure or improvement of urinary incontinence in women.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Trials Register (searched 8 November 2010) and the reference lists of relevant articles.

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials of treatment for urinary incontinence in which at least one management arm involved periurethral or transurethral injection therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed methodological quality of each study using explicit criteria. Data extraction was undertaken independently and clarification concerning possible unreported data sought directly from the investigators.

MAIN RESULTS

Excluding duplicate reports, we identified 14 trials (excluding one that was subsequently withdrawn from publication and not included in this analysis) including 2004 women that met the inclusion criteria. The limited data available were not suitable for meta-analysis because they all came from separate trials. Trials were small and generally of moderate quality.One trial of 45 women that compared injection therapy with conservative treatment showed early benefit for the injectable with respect to continence grade (risk ratio (RR) 0.7, 95% confidence interval (CI) 0.52 to 0.94) and quality of life (RR 0.54, 95% CI 0.16 to 0.92). Another, comparing Injection of autologous fat with placebo, terminated early because of safety concerns. Two trials that compared injection with surgical management found significantly better objective cure in the surgical group (RR 4.77, 95% CI 1.96 to 11.64; and RR 1.69, 95% CI 1.02 to 2.79), although the latter trial data did not reach statistical significance if an intention-to-treat analysis was used.Eight trials compared different agents and all results had wide confidence intervals. Silicone particles, calcium hydroxylapatite, ethylene vinyl alcohol, carbon spheres and dextranomer hyaluronic acid combination gave improvements which were not shown to be more or less efficacious than collagen. Dextranomer hyaluronic acid compound treated patients appeared to have significantly higher rates of injection site complications (16% with the hyaluronic acid compound versus none with collagen; RR 37.78, 95% CI 2.34 to 610) and this product has now been withdrawn from the market.A comparison of periurethral and transurethral methods of injection found similar outcomes but a higher (though not statistically significant) rate of early complications in the periurethral group. One trial of 30 women showed a weak (but not clinically significant) advantage for patient satisfaction (data not suitable for analysis in Revman) after mid-urethral injection in comparison to bladder neck injection but with no demonstrable difference in continence levels.

AUTHORS' CONCLUSIONS

The available evidence base remains insufficient to guide practice. In addition, the finding that placebo saline injection was followed by a similar symptomatic improvement to bulking agent injection raises questions about the mechanism of any beneficial effects. One small trial comparing silicone particles with pelvic floor muscle training was suggestive of benefit at three months but it is not known if this was sustained, and the treatment was associated with high levels of postoperative retention and dysuria. Greater symptomatic improvement was observed with surgical treatments, though the advantages need to be set against likely higher risks. No clear-cut conclusions could be drawn from trials comparing alternative agents, although dextranomer hyaluronic acid was associated with more local side effects and is no longer commercially available for this indication. There is insufficient evidence to show superiority of mid-urethral or bladder neck injection. The single trial of autologous fat provides a reminder that periurethral injections can occasionally cause serious side effects.

Stem cell therapy for stress urinary incontinence: a critical review

Stress urinary incontinence (SUI) is a prevailing health problem that severely impacts quality of life. Because SUI is mainly due to urethral sphincter deficiency, several preclinical and clinical trials have investigated whether transplantation of patient's own skeletal muscle-derived cells (SkMDCs) can restore the sphincter musculature. The specific cell type of SkMDCs has been described as myoblasts, satellite cells, muscle progenitor cells, or muscle-derived stem cells, and thus may vary from study to study. In more recent years, other stem cell (SC) types have also been tested, including those from the bone marrow, umbilical cord blood, and adipose tissue. These studies were mostly preclinical and utilized rat SUI models that were established predominantly by pudendal or sciatic nerve injury. Less frequently used animal models were sphincter injury and vaginal distension. While transurethral injection of SCs was employed almost exclusively in clinical trials, periurethral injection was used in all preclinical trials. Intravenous injection was also used in one preclinical study. Functional assessment of therapeutic efficacy in preclinical studies has relied almost exclusively on leak point pressure measurement. Histological assessment examined the sphincter muscle content, existence of transplanted SCs, and possible differentiation of these SCs. While all of these studies reported favorable functional and histological outcomes, there are questions about the validity of the animal model and claims of multilineage differentiation. In any event, SC transplantation appears to be a promising treatment for SUI.

The potential of stem cells in the treatment of skeletal muscle injury and disease

Tissue engineering is a pioneering field with huge advances in recent times. These advances are not only in the understanding of how cells can be manipulated but also in potential clinical applications. Thus, tissue engineering, when applied to skeletal muscle cells, is an area of huge prospective benefit to patients with muscle disease/damage. This could include damage to muscle from trauma and include genetic abnormalities, for example, muscular dystrophies. Much of this research thus far has been focused on satellite cells, however, mesenchymal stem cells have more recently come to the fore. In particular, results of trials and further research into their use in heart failure, stress incontinence, and muscular dystrophies are eagerly awaited. Although no doubt, stem cells will have much to offer in the future, the results of further research still limit their use.

Increased urethral resistance by periurethral injection of low serum cultured adipose-derived mesenchymal stromal cells in rats

OBJECTIVES

To evaluate the effects of a periurethral injection of low serum cultured adipose tissue-derived mesenchymal stromal cells (LASC) and to develop a new autologous cell therapy for stress urinary incontinence.

METHODS

F344 rats were divided into three groups as based on the periurethral injection of LASC, GAX collagen or vehicle (control). At 2 and 4 weeks after injection, leak point pressure (LPP) was measured before and after transection of the pelvic nerves. For cell tracking, LASC of green fluorescent protein transgenic rats were injected into nude rats.

RESULTS

At 2 weeks, both the LASC and collagen groups showed significantly higher LPP than the control group. At 4 weeks, the increase in LPP in the LASC group remained, whereas LPP in the collagen group decreased to baseline levels. In the absence of the urethral closure reflex after transection of the pelvic nerves, LPP in the LASC group was significantly higher than that in the other two groups. Histologically, the size of the urethral lumen was smaller in the LASC group than the collagen group. At 4 weeks, most of the LASC were positive for myogenic antigens including α-smooth muscle actin, desmin and calponin I.

CONCLUSIONS

Periurethral injection of autologous LASC capable of myogenic differentiation made a greater contribution to the increase in urethral resistance than did the conventional collagen bulk injection. Thus, its use for treatment of stress urinary incontinence can be postulated.

The treatment of female stress urinary incontinence: an evidenced-based review

OBJECTIVE

To review the literature on the surgical and nonsurgical treatment options for stress urinary incontinence in women, focusing exclusively on randomized clinical trials and high quality meta-analyses.

MATERIALS AND METHODS

A computer-aided and manual search for published randomized controlled trials and high quality meta-analyses investigating both conservative and surgical treatment options for stress urinary incontinence. In the case of a treatment that is not studied in these formats large case series have been used.

RESULTS

Articles were reviewed and the results summarized on pelvic floor physical therapy, pharmacotherapy, bulking agents, and surgery (open and minimally invasive).

CONCLUSION

There are numerous high quality studies in the literature. It can be difficult to make definitive conclusions on the most appropriate treatment options due to the variability in the outcomes used to define success in these articles. There is also a dire lack of studies evaluating and comparing the surgical options for patients with intrinsic sphincter deficiency.

Radical cystectomy with orthotopic neobladder for invasive bladder cancer: a critical analysis of long-term oncological, functional, and quality of life results

PURPOSE

The present contribution analyses long-term data regarding oncological, functional, and quality of life aspects of patients subjected to cystectomy due to malignancy with subsequent orthotopic bladder substitution.

METHODS

A literature search was conducted to review literature published from 1887 until today. Oncological aspects, special considerations on female patients, quality of life, geriatric patients, and impact of minimally invasive surgery were also addressed and discussed.

RESULTS

After more than three decades, orthotopic bladder substitution subsequent to radical cystectomy has stood the test of time by providing adequate long-term survival and low local recurrence rates. Compared to radical cystectomy, neither radiation nor chemotherapy, nor a combination of both, offer similar long-term results. Orthotopic bladder substitution does not compromise oncological outcome and can be performed with excellent results regarding functional and quality of life issues. Chronological age is generally not a contraindication for cystectomy.

CONCLUSION

Orthotopic bladder substitution should be the diversion of choice both in men and in women, whenever possible. For orthotopic urinary diversion, a careful patient selection considering tumor extent, patient motivation, preoperative sphincter function, other local and systemic adverse confounding factors, and overall life expectancy must be taken into account. Minimally invasive techniques are promising concepts for the future, awaiting confirmation in larger patient cohorts.

Stem cells for the treatment of urinary incontinence

Stress urinary incontinence (SUI) is highly prevalent. As of now, there is no minimally invasive long-term treatment available. Adult stem cells are nonimmunogenic and have the ability to self-renew and to differentiate into multiple cell types. Over the past decade, in vivo studies have described periurethral injections of adult-derived stem cells for the treatment of SUI. The ultimate goal has been to achieve a permanent cure for SUI by restoration of the intrinsic and extrinsic urethral sphincter and the surrounding connective tissue, including peripheral nerves and blood vessels. For this purpose, future studies need to focus on delivery systems, cell survival, and functional improvement of the urethral closure mechanism, including improvement of innervation and vascularization.

Expression of monocyte chemotactic protein 3 following simulated birth trauma in a murine model of obesity

OBJECTIVE

To determine the effect of obesity on simulated birth trauma in leptin-deficient obese mice as measured by relative monocyte chemotactic protein 3 (MCP-3) expression.

MATERIALS AND METHODS

A total of 25 wild-type and 25 obese C57BL/6 virgin female mice underwent 1 hour of vaginal distension (VD), sham VD, or anesthesia without VD. Pelvic organ tissues were then harvested either immediately or 24-hours post VD and subsequent real-time polymerase chain reaction analysis was performed.

RESULTS

Urethral MCP-3 levels in wild-type mice were elevated from baseline at 0 hours with a return to baseline at 24 hours in both VD and sham VD groups. In obese mice, there was a 6-fold elevation in MCP-3 levels at 0 hours after sham VD vs control (P <.05), which then returned to baseline levels at 24 hours. After undergoing VD, MCP-3 levels increased to 6-fold baseline values (P = .002) at 0 hours, with continued elevation in MCP-3 levels to 15 times control levels (P = .0003) at 24 hours.

CONCLUSIONS

MCP-3 is significantly over-expressed in the urethral tissues of both wild-type and obese mice immediately after any urethral manipulation. At 24 hours, the MCP-3 expression patterns become divergent between VD and sham VD in obese mice. With a greater degree of trauma, MCP-3 continued to rise at 24 hours, suggesting that the underlying obesity resulted in alterations in response to tissue injury, paralleling the degree of injury. Such associations warrant further investigation into the role of MCP-3 as a chemokine for stem cell migration, with implications for subsequent tissue repair mechanisms after birth trauma.

Functional external anal sphincter reconstruction for treatment of anal incontinence using muscle progenitor cell auto grafting

PURPOSE

This study aimed to investigate the feasibility of autologous muscle progenitor cell transplantation for anal sphincter regeneration in a rabbit model of anal incontinence. We examined the serial changes in structure, with particular emphasis on histology and functional properties of the anal sphincter.

METHODS

External anal sphincterotomy was performed in 21 rabbits; these rabbits were randomly assigned to 2 groups. In group I (n = 9), autologous muscle progenitor cells were isolated from quadriceps myofiber explants, labeled with PKH-26, and injected into sphincter 3 weeks after sphincterotomy. In group II (n = 12), saline buffer was injected at the site of damage. Sphincter electromyography and manometry were performed immediately before sphincterotomy and 14, 28, and 60 days after injection in 3 animals in each group at every interval and the findings were correlated with histomorphological studies. In addition, electromyography and manometry were performed in the remaining 3 rabbits in group II after 6 months.

RESULTS

In group II, a flaccid sphincter persisted during the 6 months of follow-up. In group I, muscle progenitor autografting accelerated sphincter myofiber repair and improvement in functional capacity of the damaged sphincter. Fluorescently labeled cells were detected in all of the grafted sphincters; regenerated myotubes were detectable at the injection site as evidenced by the presence of desmin. We also observed a significant decrease in interstitial fibrosis in the 4th week and strikingly higher amounts of Ki-67-positive cells in group I. Manometry and electromyography showed a significant improvement in the mean resting anal canal pressure and sphincteric electrical activity 4 weeks after cell injection, respectively.

CONCLUSION

Transplanting muscle progenitor cells showed the potential for recapitulation of a myogenic program when injected into deficient rabbit anal sphincter. Objective anal measures of resting and stimulated pressures and electromyographic profile improved. Stem cell-mediated anal myoplasty warrants additional investigation as a new method to treat anal incontinence before attempting this modality in the clinical setting.

Mesenchymal stem cell seeded knitted silk sling for the treatment of stress urinary incontinence

Stress urinary incontinence remains a worldwide problem affecting patients of all ages. Implantation of suburethral sling is the cornerstone treatment. Current slings have inherent disadvantages. This study aims to develop a tissue engineered sling with bone marrow derived mesenchymal stem cell seeded degradable silk scaffold. The mesenchymal stem cells were obtained from Sprague-Dawley rats and were characterized in vitro. Layered cell sheets were formed after two weeks of culture and were labeled with carboxyfluorescein diacetate. Forty female rats were divided into four groups: Group A (n=5) had sham operation; other three groups underwent bilateral proximal sciatic nerve transection and were confirmed with stress urinary incontinence by the leak-point pressure measurement at 4 weeks after operation. Then, Group B (n=5) had no sling placed; Group C (n=15) was treated with a silk sling; and Group D (n=15) was treated with the tissue engineered sling. Histology and the leak-point pressure measurements were done at 4 and 12 weeks after the sling implantation while collagen content and mechanical testing were done at 12 weeks. The results showed that Group B had a significantly lower leak-point pressure (24.0+/-4.2 cmH(2)O) at 4 weeks (P<0.05), while Group C (38.0+/-3.3 cmH(2)O) and Group D (36.3+/-3.1 cmH(2)O) almost reached to the normal level shown by Group A (41.6+/-3.8 cmH(2)O) (p>0.05). At 12 weeks, tissue engineered sling of group D has higher collagen content (70.84+/-14.49 microg/mg) and failure force (2.436+/-0.192 N) when compared those of Group C (38.94+/-7.05 microg/mg and 1.521+/-0.087 N) (p<0.05). Both the silk sling and tissue engineered sling showed convincing functional effects for the treatment of stress urinary incontinence in a rat model. And the better ligament-like tissue formation in the tissue engineered sling suggested potential long-term function.

Autologous bone-marrow-derived mesenchymal stem cell transplantation into injured rat urethral sphincter

OBJECTIVES

To evaluate the functional and histological recovery by autologous bone-marrow-derived mesenchymal stem cell (BMSC) transplantation into injured rat urethral sphincters.

METHODS

BMSC were harvested from female Sprague-Dawley retired breeder rats for later transplantation. The cells were cultured, and transfected with the green fluorescence protein gene. The urethral sphincters were injured by combined urethrolysis and cardiotoxin injection. One week after injury, the cultured BMSC were injected autologously into the periurethral tissues. Controls included sham-operated rats and injured rats injected with cell-free medium (CFM). Abdominal leak point pressures (LPP) were measured before and after surgery during the following 13 weeks. The urethras were then retrieved for histological evaluation. The presence of green-fluorescence-protein-labeled cells and the regeneration of skeletal muscles, smooth muscles, and peripheral nerves were evaluated by immunohistochemical staining.

RESULTS

LPP was significantly reduced in the injured rats. It increased gradually after transplantation, but there was no significant difference between the BMSC and CFM groups. In the BMSC group, transplanted cells survived and differentiated into striated muscle cells and peripheral nerve cells. The proportions of skeletal muscle cells and peripheral nerves in the urethra were significantly greater in the BMSC group compared to the CFM group.

CONCLUSIONS

Despite a clear trend towards recovery of LPP in BMSC-transplanted urethras, no significant effect was detected. Further study is required for clinical applications for the treatment of stress urinary incontinence.