Muscle-derived cell-mediated ex vivo gene therapy for urological dysfunction

Stem cell therapy combined with controlled release of growth factors for the treatment of sphincter dysfunction

Sphincter dysfunction often occurs at the end of tubule organs such as the urethra, anus, or gastroesophageal sphincters. It is the primary consequence of neuromuscular impairment caused by trauma, inflammation, and aging. Despite intensive efforts to recover sphincter function, pharmacological treatments have not achieved significant improvement. Cell- or growth factor-based therapy is a promising approach for neuromuscular regeneration and the recovery of sphincter function. However, a decrease in cell retention and viability, or the short half-life and rapid degradation of growth factors after implantation, remain obstacles to the translation of these therapies to the clinic. Natural biomaterials provide unique tools for controlled growth factor delivery, which leads to better outcomes for sphincter function recovery in vivo when stem cells and growth factors are co-administrated, in comparison to the delivery of single therapies. In this review, we discuss the role of stem cells combined with the controlled release of growth factors, the methods used for delivery, their potential therapeutic role in neuromuscular repair, and the outcomes of preclinical studies using combination therapy, with the hope of providing new therapeutic strategies to treat incontinence or sphincter dysfunction of the urethra, anus, or gastroesophageal tissues, respectively.

Exosome biopotentiated hydrogel restores damaged skeletal muscle in a porcine model of stress urinary incontinence

Urinary incontinence afflicts up to 40% of adult women in the United States. Stress urinary incontinence (SUI) accounts for approximately one-third of these cases, precipitating ~200,000 surgical procedures annually. Continence is maintained through the interplay of sub-urethral support and urethral sphincter coaptation, particularly during activities that increase intra-abdominal pressure. Currently, surgical correction of SUI focuses on the re-establishment of sub-urethral support. However, mesh-based repairs are associated with foreign body reactions and poor localized tissue healing, which leads to mesh exposure, prompting the pursuit of technologies that restore external urethral sphincter function and limit surgical risk. The present work utilizes a human platelet-derived CD41a and CD9 expressing extracellular vesicle product (PEP) enriched for NF-κB and PD-L1 and derived to ensure the preservation of lipid bilayer for enhanced stability and compatibility with hydrogel-based sustained delivery approaches. In vitro, the application of PEP to skeletal muscle satellite cells in vitro drove proliferation and differentiation in an NF-κB-dependent fashion, with full inhibition of impact on exposure to resveratrol. PEP biopotentiation of collagen-1 and fibrin glue hydrogel achieved sustained exosome release at 37 °C, creating an ultrastructural “bead on a string” pattern on scanning electron microscopy. Initial testing in a rodent model of latissimus dorsi injury documented activation of skeletal muscle proliferation of healing. In a porcine model of stress urinary incontinence, delivery of PEP-biopotentiated collagen-1 induced functional restoration of the external urethral sphincter. The histological evaluation found that sustained PEP release was associated with new skeletal muscle formation and polarization of local macrophages towards the regenerative M2 phenotype. The results provided herein serve as the first description of PEP-based biopotentiation of hydrogels implemented to restore skeletal muscle function and may serve as a promising approach for the nonsurgical management of SUI.

Current and Future Directions of Stem Cell Therapy for Bladder Dysfunction

Stem cells are capable of self-renewal and differentiation into a range of cell types and promote the release of chemokines and progenitor cells necessary for tissue regeneration. Mesenchymal stem cells are multipotent progenitor cells with enhanced proliferation and differentiation capabilities and less tumorigenicity than conventional adult stem cells; these cells are also easier to acquire. Bladder dysfunction is often chronic in nature with limited treatment modalities due to its undetermined pathophysiology. Most treatments focus on symptom alleviation rather than pathognomonic changes repair. The potential of stem cell therapy for bladder dysfunction has been reported in preclinical models for stress urinary incontinence, overactive bladder, detrusor underactivity, and interstitial cystitis/bladder pain syndrome. Despite these findings, however, stem cell therapy is not yet available for clinical use. Only one pilot study on detrusor underactivity and a handful of clinical trials on stress urinary incontinence have reported the effects of stem cell treatment. This limitation may be due to stem cell function loss following ex vivo expansion, poor in vivo engraftment or survival after transplantation, or a lack of understanding of the precise mechanisms of action underlying therapeutic outcomes and in vivo behavior of stem cells administered to target organs. Efficacy comparisons with existing treatment modalities are also needed for the successful clinical application of stem cell therapies. This review describes the current status of stem cell research on treating bladder dysfunction and suggests future directions to facilitate clinical applications of this promising treatment modality, particularly for bladder dysfunction.

Generation of myogenic progenitor cell-derived smooth muscle cells for sphincter regeneration

BACKGROUND

Degeneration of smooth muscles in sphincters can cause debilitating diseases such as fecal incontinence. Skeletal muscle-derived cells have been effectively used in clinics for the regeneration of the skeletal muscle sphincters, such as the external anal or urinary sphincter. However, little is known about the in vitro smooth muscle differentiation potential and in vivo regenerative potential of skeletal muscle-derived cells.

METHODS

Myogenic progenitor cells (MPC) were isolated from the skeletal muscle and analyzed by flow cytometry and in vitro differentiation assays. The differentiation of MPC to smooth muscle cells (MPC-SMC) was evaluated by immunofluorescence, flow cytometry, patch-clamp, collagen contraction, and microarray gene expression analysis. In vivo engraftment of MPC-SMC was monitored by transplanting reporter protein-expressing cells into the pyloric sphincter of immunodeficient mice.

RESULTS

MPC derived from human skeletal muscle expressed mesenchymal surface markers and exhibit skeletal myogenic differentiation potential in vitro. In contrast, they lack hematopoietic surface marker, as well as adipogenic, osteogenic, and chondrogenic differentiation potential in vitro. Cultivation of MPC in smooth muscle differentiation medium significantly increases the fraction of alpha smooth muscle actin (aSMA) and smoothelin-positive cells, while leaving the number of desmin-positive cells unchanged. Smooth muscle-differentiated MPC (MPC-SMC) exhibit increased expression of smooth muscle-related genes, significantly enhanced numbers of CD146- and CD49a-positive cells, and in vitro contractility and express functional Cav and Kv channels. MPC to MPC-SMC differentiation was also accompanied by a reduction in their skeletal muscle differentiation potential. Upon removal of the smooth muscle differentiation medium, a major fraction of MPC-SMC remained positive for aSMA, suggesting the definitive acquisition of their phenotype. Transplantation of murine MPC-SMC into the mouse pyloric sphincter revealed engraftment of MPC-SMC based on aSMA protein expression within the host smooth muscle tissue.

CONCLUSIONS

Our work confirms the ability of MPC to give rise to smooth muscle cells (MPC-SMC) with a well-defined and stable phenotype. Moreover, the engraftment of in vitro-differentiated murine MPC-SMC into the pyloric sphincter in vivo underscores the potential of this cell population as a novel cell therapeutic treatment for smooth muscle regeneration of sphincters.

Underactive Bladder; Review of Progress and Impact From the International CURE-UAB Initiative

There is a significant need for research and understanding of underactive bladder (UAB). The International Congress of Urologic Research and Education on Aging UnderActive Bladder (CURE-UAB) was organized by Doctors Michael Chancellor and Ananias Diokno in order to address these concerns. CURE-UAB was supported, in part, by the US National Institute of Aging and National Institute of Diabetes Digestive and Kidney. Since 2014, there have been 5 successful CURE-UAB congresses. They have brought together diverse stakeholders in the UAB field to identify areas of major scientific challenge and initiated a call to action among the medical community. In this review, we will highlight current and novel treatments under development for UAB and the progress and impact from the CURE-UAB initiative.

Harnessing the mesenchymal stem cell secretome for regenerative urology

The extensive arsenal of bioactive molecules secreted by mesenchymal stem cells (MSCs), known as the secretome, has demonstrated considerable therapeutic benefit in regenerative medicine. Investigation into the therapeutic potential of the secretome has enabled researchers to replicate the anti-inflammatory, pro-angiogenic and trophic effects of stem cells without the need for the cells themselves. Furthermore, treatment with the MSC secretome could circumvent hurdles associated with cellular therapy, including oncogenic transformation, immunoreactivity and cost. Thus, a clear rationale exists for investigating the therapeutic potential of the MSC secretome in regenerative urology. Indeed, preclinical studies have demonstrated the therapeutic benefits of the MSC secretome in models of stress urinary incontinence, renal disease, bladder dysfunction and erectile dysfunction. However, the specific mechanisms underpinning therapeutic activity are unclear and require further research before clinical translation. Improvements in current proteomic methods used to characterize the secretome will be necessary to provide further insight into stem cells and their secretome in regenerative urology.

Underactive bladder: A review of the current treatment concepts

According to the International Continence Society standardization reports, underactive bladder (UAB) is a decrease in detrusor contraction and/or shortening of the contraction time, resulting in an incomplete and/or prolongation of the bladder emptying within the normal time frame. It has been indicated that idiopathic, neurogenic, myogenic, and iatrogenic factors play a role in the etiology. To make a diagnosis, it is absolutely necessary to perform a pressure-flow study. Treatment alternatives are generally based on the evacuation of the lower urinary tract, independent of the etiology. UAB treatments are listed under the headings of conservative methods and clean intermittent catheterization, pharmacotherapy (alpha-blockers, cholinesterase inhibitors, muscarinic agonists, prostaglandin E2, and acotiamide), surgical treatments (sacral nerve stimulation-electrical stimulation, injections into the external sphincter, surgeries to be performed for bladder outlet obstruction, reduction cystoplasty, and latissimus dorsi detrusor myoplasty), and stem cell and gene therapies. It is still controversial whether satisfactory success is achieved in the treatment of patients with UAB. Owing to the better understanding of the pathophysiology, future developments in the pharmaceutical industry, gene therapy, and biomedical applications are expected to close the gap in the treatment.

Detrusor underactivity in women: A current understanding

AIMS

To examine the current understanding and management of detrusor underactivity (DUA) and underactive bladder (UAB) in women.

METHODS

A review of the current literature was performed with a specific focus on new management strategies and treatment options for women with DUA and UAB.

RESULTS

DUA has become an area of increased interest in recent years. Affecting up to 45% of older women undergoing urodynamic evaluation for non-neurogenic lower urinary tract symptoms, DUA is common. There are a variety of possible etiologies including neurogenic or myogenic dysfunction. As there is currently no cure for DUA and no way to restore the ability of the detrusor muscle to contract, management of DUA in women is mostly focused on effective bladder drainage by urinary catheterization. Clean intermittent catheterization is the gold standard for bladder drainage however for a variety of reasons, women with DUA often are managed with indwelling urethral catheter or suprapubic tube. Medications, sacral neuromodulation, and the inFlow urinary prosthesis are also treatment alternatives or additions to catheterization. Novel therapies using stem cells and gene therapy are also under investigation for the treatment of DUA and UAB.

CONCLUSIONS

DUA is likely more prevalent than recognized and undertreated in women. It is vital that further research in treatment options beyond catheterization be developed for these patients to offer patients a variety of treatment options.

Hormonal oral contraceptive influence on isolation, Characterization and cryopreservation of mesenchymal stem cells from menstrual fluid

The purpose of the study was to evaluate whether the intake of hormonal oral contraceptive influences the viability of mesenchymal stem cell. Sixteen healthy female volunteers with regular menstrual cycles were invited to participate. Menstrual fluid was collected on the day of maximum flux, and collected cells were analyzed by a 'minimal standard' for MSC characterization: plastic adherence, trilineage (adipogenic, osteogenic, chondrogenic) in vitro differentiation and a minimalistic panel of markers assessed by flow cytometry (CD731, CD901, CD1051, CD34-, CD45-) using monoclonal antibodies. The participants were divided into two groups: Group 1 - no hormonal contraceptive use; Group 2 - hormonal oral contraceptive use. The median of the menstrual fluid volume was 5.0 and the median number of cells was 5.2 × 10⁶. Median of cell viability was 89.3%. After culture, mesenchymal stem cells increased from 0.031% of the total cells to 96.9%. The cells formed clusters and reached confluence after 15-21 days of culture in the first passage. In the second passage, clusters and the confluence were observed after 3 days of culture. No difference was observed between the groups. Our data suggest that oral hormonal contraceptive intake maintains the viability of mesenchymal stem cells from menstrual fluid.

Identification and Characterization of Skeletal Muscle Stem Cells from Human Orbicularis Oculi Muscle

Skeletal muscle stem cell (SMSC) transplantation has shown great therapeutical potential in repairing muscle loss and dysfunction, but the muscle acquisition is usually a traumatic procedure causing pain and morbidity to the donor. In this study, we investigated the feasibility of isolating SMSCs from human orbicularis oculi muscle (OOM), which is routinely removed and discarded during ophthalmic cosmetic surgeries. OOM fragments were harvested from 18 female healthy donors undergoing upper eyelid plasties. Plastic-adherent cells were isolated from the muscles using a two-step plating method combined with collagenase digestion. A total of 15 cell cultures were successfully established from the muscle samples. These adherent cells were positive for the specific markers of SMSCs and could be directed toward the osteogenic, adipogenic, chondrogenic, and myogenic phenotypes in the presence of lineage-specific inductive media. Moreover, after cultured in the myogenic inductive medium for 3 weeks, the muscle cells were injected into the tibialis anterior muscles of nude mice and the cell fate was detected using a DiI-labeling technique. In vivo myogenesis was evidenced by the expression of DiI fluorescence after cell transplantation. The donor cells could be found in the satellite cell position and incorporated into the host myofibers. Our results demonstrated that human OOM represents a novel source of myogenic precursors with stem cell-like properties, which may provide a foundation for the SMSC-based therapeutics of skeletal muscle diseases.

Current concepts of the acontractile bladder

The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments.

Recent advances in the understanding and management of underactive bladder

Underactive bladder (UAB) is an important and complex urological condition resulting from the urodynamic finding of detrusor underactivity. It can manifest in a wide range of lower urinary tract symptoms, from voiding to storage complaints, and can overlap with other conditions, including overactive bladder and bladder outlet obstruction. However, UAB continues to be poorly understood and inadequately researched. In this article, we review the contemporary literature pertaining to recent advances in defining, understanding, and managing UAB.

Modelling human myoblasts survival upon xenotransplantation into immunodeficient mouse muscle

Cell transplantation has been challenged in several clinical indications of genetic or acquired muscular diseases, but therapeutic success were mitigated. To understand and improve the yields of tissue regeneration, we aimed at modelling the fate of CD56-positive human myoblasts after transplantation. Using immunodeficient severe combined immunodeficiency (SCID) mice as recipients, we assessed the survival, integration and satellite cell niche occupancy of human myoblasts by a triple immunohistochemical labelling of laminin, dystrophin and human lamin A/C. The counts were integrated into a classical mathematical decline equation. After injection, human cells were essentially located in the endomysium, then they disappeared progressively from D0 to D28. The final number of integrated human nuclei was grossly determined at D2 after injection, suggesting that no more efficient fusion between donor myoblasts and host fibers occurs after the resolution of the local damages created by needle insertion. Almost 1% of implanted human cells occupied a satellite-like cell niche. Our mathematical model validated by histological counting provided a reliable quantitative estimate of human myoblast survival and/or incorporation into SCID muscle fibers. Informations brought by histological labelling and this mathematical model are complementary.

Addressing challenges in underactive bladder: recommendations and insights from the Congress on Underactive Bladder (CURE-UAB)

Underactive bladder (UAB) is an expanding troublesome health issue, exerting a major influence on the health and independence of older people with a disproportionally low level of attention received. The 2nd International Congress on Underactive Bladder (CURE-UAB 2) convened in Denver, CO on December 3 and 4, 2015, and comprised of top clinicians, scientists, and other stakeholders to address the challenges in UAB. A series of workshops aimed to define UAB and its phenotype, define detrusor underactivity (DU) and create a subtyping of DU, evaluate existing animal models for DU, and lastly to establish research priorities for UAB.

Basal Lamina Mimetic Nanofibrous Peptide Networks for Skeletal Myogenesis

Extracellular matrix (ECM) is crucial for the coordination and regulation of cell adhesion, recruitment, differentiation and death. Therefore, equilibrium between cell-cell and cell-matrix interactions and matrix-associated signals are important for the normal functioning of cells, as well as for regeneration. In this work, we describe importance of adhesive signals for myoblast cells' growth and differentiation by generating a novel ECM mimetic peptide nanofiber scaffold system. We show that not only structure but also composition of bioactive signals are important for cell adhesion, growth and differentiation by mimicking the compositional and structural properties of native skeletal muscle basal lamina. We conjugated laminin-derived integrin binding peptide sequence, "IKVAV", and fibronectin-derived well known adhesive sequence, "RGD", into peptide nanostructures to provide adhesive and myogenic cues on a nanofibrous morphology. The myogenic and adhesive signals exhibited a synergistic effect on model myoblasts, C2C12 cells. Our results showed that self-assembled peptide nanofibers presenting laminin derived epitopes support adhesion, growth and proliferation of the cells and significantly promote the expression of skeletal muscle-specific marker genes. The functional peptide nanofibers used in this study present a biocompatible and biodegradable microenvironment, which is capable of supporting the growth and differentiation of C2C12 myoblasts into myotubes.

Underactive Bladder in Older Adults

Overactive bladder is one of the most common bladder problems, but an estimated 20 million Americans have underactive bladder (UAB), which makes going to the bathroom difficult, increases the risk of urinary tract infections, and even leads to institutionalization. This article provides an overview of UAB in older adults, and discusses the prevalence, predisposing factors, cause, clinical investigations, and treatments. At present, there is no effective therapy for UAB. A great deal of work still needs to be done on understanding the pathogenesis and the development of effective therapies.

Intradetrusor injection of adult muscle-derived cells for the treatment of underactive bladder: pilot study

We conducted the first-regenerative medicine cellular therapy for underactive bladder (UAB) in an FDA-approved, compassionate-use IND trial to evaluate treatment safety and potential clinical efficacy of autologous muscle-derived stem cells (AMDC) on a patient with UAB. No study-related adverse events or side effects were reported. In the 1-year follow-up period, the subject denied any gross hematuria, urgency, frequency or infection. A reduction in maximum cystometric capacity from 844 to 663 mL was observed, and the patient was able to void small amounts but continues to require self-catheterization 1 year after AMDC injection. Intradetrusor injection of AMDC is safe, minimally invasive and a promising treatment option for the UAB.

Stem cell transplantation for treating Duchenne muscular dystrophy: A Web of Science-based literature analysis

OBJECTIVE:

To identify global research trends in stem cell transplantation for treating Duchenne muscular dystrophy using a bibliometric analysis of Web of Science.

DATA RETRIEVAL:

We performed a bibliometric analysis of studies on stem cell transplantation for treating Duchenne muscular dystrophy from 2002 to 2011 retrieved from Web of Science.

SELECTION CRITERIA:

Inclusion criteria: (a) peer-reviewed published articles on stem cell transplantation for treating Duchenne muscular dystrophy indexed in Web of Science; (b) original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items; and (c) publication between 2002 and 2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) documents that were not published in the public domain; and (c) corrected papers.

MAIN OUTCOME MEASURES:

(1) Annual publication output; (2) distribution according to subject areas; (3) distribution according to journals; (4) distribution according to country; (5) distribution according to institution; (6) distribution according to institution in China; (7) distribution according to institution that cooperated with Chinese institutions; (8) top-cited articles from 2002 to 2006; (9) top-cited articles from 2007 to 2011.

RESULTS:

A total of 318 publications on stem cell transplantation for treating Duchenne muscular dystrophy were retrieved from Web of Science from 2002 to 2011, of which almost half derived from American authors and institutes. The number of publications has gradually increased over the past 10 years. Most papers appeared in journals with a focus on gene and molecular research, such as Molecular Therapy, Neuromuscular Disorders, and PLoS One. The 10 most-cited papers from 2002 to 2006 were mostly about different kinds of stem cell transplantation for muscle regeneration, while the 10 most-cited papers from 2007 to 2011 were mostly about new techniques of stem cell transplantation for treating Duchenne muscular dystrophy.

CONCLUSION:

The publications on stem cell transplantation for treating Duchenne muscular dystrophy were relatively few. It also needs more research to confirm that stem cell therapy is a reliable treatment for Duchenne muscular dystrophy.

A novel method for differentiation of human mesenchymal stem cells into smooth muscle-like cells on clinically deliverable thermally induced phase separation microspheres

Muscle degeneration is a prevalent disease, particularly in aging societies where it has a huge impact on quality of life and incurs colossal health costs. Suitable donor sources of smooth muscle cells are limited and minimally invasive therapeutic approaches are sought that will augment muscle volume by delivering cells to damaged or degenerated areas of muscle. For the first time, we report the use of highly porous microcarriers produced using thermally induced phase separation (TIPS) to expand and differentiate adipose-derived mesenchymal stem cells (AdMSCs) into smooth muscle-like cells in a format that requires minimal manipulation before clinical delivery. AdMSCs readily attached to the surface of TIPS microcarriers and proliferated while maintained in suspension culture for 12 days. Switching the incubation medium to a differentiation medium containing 2 ng/mL transforming growth factor beta-1 resulted in a significant increase in both the mRNA and protein expression of cell contractile apparatus components caldesmon, calponin, and myosin heavy chains, indicative of a smooth muscle cell-like phenotype. Growth of smooth muscle cells on the surface of the microcarriers caused no change to the integrity of the polymer microspheres making them suitable for a cell-delivery vehicle. Our results indicate that TIPS microspheres provide an ideal substrate for the expansion and differentiation of AdMSCs into smooth muscle-like cells as well as a microcarrier delivery vehicle for the attached cells ready for therapeutic applications.

Dynamics of acute local inflammatory response after autologous transplantation of muscle-derived cells into the skeletal muscle

The vast majority of myoblasts transplanted into the skeletal muscle die within the first week after injection. Inflammatory response to the intramuscular cell transfer was studied in allogeneic but not in autologous model. The aim of this study was to evaluate immune reaction to autotransplantation of myogenic cells and to assess its dynamics within the first week after injection. Muscle-derived cells or medium alone was injected into the intact skeletal muscles in autologous model. Tissue samples were collected 1, 3, and 7 days after the procedure. Our analysis revealed the peak increase of the gene expression of all evaluated cytokines (Il-1α, Il-1β, Il-6, Tgf-β, and Tnf-α) at day 1. The mRNA level of analyzed cytokines normalized in subsequent time points. The increase of Il-β gene expression was further confirmed at the protein level. Analysis of the tissue sections revealed rapid infiltration of injected cell clusters with neutrophils and macrophages. The inflammatory infiltration was almost completely resolved at day 7. The survived cells were able to participate in the muscle regeneration process. Presented results demonstrate that autotransplanted muscle-derived cells induce classical early immune reaction in the site of injection which may contribute to cellular graft elimination.

Isolation and osteogenic differentiation of skeletal muscle‑derived stem cells for bone tissue engineering

The purpose of this study was to investigate the isolation and culture of muscle‑derived stem cells (MDSCs) and their capability to differentiate into osteoblasts in vitro. Skeletal muscle tissue was obtained from double hind limbs of New Zealand white rabbits under sterile conditions and isolated by collagenase digestion. Following passages in basic medium, the primary cells were desmin (+), myosin (+) and CD105 (+). Differentiation of MDSCs was induced by osteogenic medium. Using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyl tetrazolium bromide assay, the differentiated cell population was found to proliferate faster than the undifferentiated. Alkaline phosphatase staining and alizarin red staining revealed that the differentiated cells were mineralized in vitro. Quantitative polymerase chain reaction assays also showed increased mRNA expression of osteogenic genes in differentiated cells. In conclusion, stem cells were successfully isolated and cultured from rabbit skeletal muscle tissue and were able to differentiate into osteoblasts following induction. These observations may indicate an ideal stem cell source for tissue engineering.

Stem cell therapy in bladder dysfunction: where are we? And where do we have to go?

To date, stem cell therapy for the bladder has been conducted mainly on an experimental basis in the areas of bladder dysfunction. The therapeutic efficacy of stem cells was originally thought to be derived from their ability to differentiate into various cell types. Studies about stem cell therapy for bladder dysfunction have been limited to an experimental basis and have been less focused than bladder regeneration. Bladder dysfunction was listed in MESH as "urinary bladder neck obstruction", "urinary bladder, overactive", and "urinary bladder, neurogenic". Using those keywords, several articles were searched and studied. The bladder dysfunction model includes bladder outlet obstruction, cryoinjured, diabetes, ischemia, and spinal cord injury. Adipose derived stem cells (ADSCs), bone marrow stem cells (BMSCs), and skeletal muscle derived stem cells (SkMSCs) are used for transplantation to treat bladder dysfunction. The main mechanisms of stem cells to reconstitute or restore bladder dysfunction are migration, differentiation, and paracrine effects. The aim of this study is to review the stem cell therapy for bladder dysfunction and to provide the status of stem cell therapy for bladder dysfunction.

Effect of human muscle-derived stem cells on cryoinjured mouse bladder contractility

OBJECTIVE

To investigate the effect of human muscle-derived stem cells (hMDSCs) on ameliorating impaired detrusor contractility in a cryoinjured bladder murine model.

METHODS

The hMDSCs were isolated and cultured by modified preplate technique, and only CD34-positive hMDSCs were extracted by Mini-MACS kits. Isolated hMDSCs were prelabeled with PKH26 and injected into the cryoinjured bladder to observe the pattern and characteristics. The nude mice were subdivided into three groups: normal group (N), cryoinjury bladder group with saline injection (C), and hMDSCs injection group after cryoinjury (M). At 2 weeks after injecting hMDSCs, we compared the contractility of bladder muscle strip stimulated by electrical field stimulation (EFS), acetylcholine (Ach.), and adenosine triphosphate (ATP), and the bladder smooth muscle tissue was examined by immunohistochemistry.

RESULTS

The contractile powers of bladder muscle strip in the C group were more decreased than the N group after EFS, Ach, and ATP treatment (P < .05). The bladder contractility of the M group was more increased than in the C group (P < .05), but was lower than the N group after EFS and Ach treatment. However, there was no significant difference of contractile power between the C and M groups after ATP stimulation. In immunohistochemical staining, the thickness of the bladder smooth muscle layer in the M group was significantly increased compared with the C group, and PKH26-labeled implanted cells were positive for smooth muscle cell differentiation marker (α-SMA) in the injected region.

CONCLUSION

hMDSCs injection increased cholinergic bladder contractile power but not the purinergic component of bladder contraction after cryoinjury.

[Cellular therapy and urinary incontinence]

AIM

The objective of the current study was to perform a review of literature concerning stem cells therapy (preclinical and clinical studies) applied to the treatment of stress urinary incontinence (SUI).

METHODS

Review of literature (Pubmed/Medline) using the following key words: stem cells, urinary incontinence, stress. Among 38 published articles (English or French language), 16 studies were selected (comparative preclinical and clinical studies).

RESULTS

Multipotentes mesenchymal stem cells (MSC), present in the adults in most of the tissues derived from the mesoderm have been tested in the treatment of SUI. Three sources of MSC have been mainly used in urology: bone marrow, striated muscle and adipose tissue. The general principle consists in extracting the MSC from the source tissue and grafting these MSC in the injured urinary sphincter. The preclinical studies proved the capacity of these transplanted cells to differenciate into contractile myocytes and to reconstitute nerve junctions. Clinical studies are very different in terms of methodology, with sample size ranging from four to 123 subjects and a median follow-up of 1 year; these studies showed success rates (complete continence) ranging from 12 to 79 % and improvement rates (quality of life and/or pad test) from 13 to 66%. Only one study reported two cases of worsening incontinence after cell therapy.

CONCLUSION

The few available clinical studies have reported that at short-term follow-up, cell therapy was associated with encouraging results with few side effects.

Stem cells for urinary tract regeneration

Regeneration of the urinary bladder is a complicated task, due to organ dimensions and diseases (cancer, interstitial cystitis) when autologous bladder cells cannot be used. Cancer is the most frequent indication for bladder removal (cystectomy). Stem cells can be used with the guarantee of the sufficient cell number for the in vitro construction of the urinary bladder wall. Tissue engineering techniques hold great promise for regeneration of dysfunctional urinary sphincter. Denervation following surgical procedures or injuries results in weakness of the urethral sphincter and stress urinary incontinence. Injectable therapies and the potential of stem cells for sphincter restoration was presented in this review. The aim of this review was to present possibilities of urinary bladder regeneration with the use of stem cells and tissue engineering techniques.

Intrasphincteric autologous myoblast injections with electrical stimulation for stress urinary incontinence

OBJECTIVE

To assess the feasibility and safety of ultrasound-guided autologous myoblast injections into the external urethral sphincter followed by electrical stimulation (ES) as a possible 2-step treatment for stress urinary incontinence (SUI).

METHODS

Autologous myoblasts isolated from a biceps muscle sample were injected under transurethral ultrasound guidance into the external urethral sphincter of 38 female patients. The patients also underwent ES postoperatively to enhance cell integration. Treatment feasibility, as well as possible intraoperative and postoperative complications, was assessed 6weeks after the injections. Additionally, the effects of the myoblast injections followed by an ES cycle were compared to those of a preoperative ES cycle undergone by the same patients.

RESULTS

No serious adverse events or complications were noted and the procedure was well tolerated. Compared with the objective and subjective measurements collected after the preoperative ES cycle, the corresponding measurements obtained 6weeks postoperatively, after the completion of a second ES cycle, indicated considerable improvement. The results to the stress test were negative for 29 (78.4%) of the patients, 5 (13.5%) considered their SUI cured, and 29 (78.4%) reported improvement.

CONCLUSION

Intrasphincteric autologous myoblast injections followed by ES is minimally invasive and feasible, and safely produced promising initial results. EU Clinical Trials EudraCT No. 2009-012389-30 ClinicalTrials.gov identifier: NCT01355133.

Protective effect of sodium ascorbate on efficacy of intramuscular transplantation of autologous muscle-derived cells

INTRODUCTION

The possible reason for elimination of myogenic cells after transplantation is inflammation at the injection site associated with oxidative stress. The aim of this study was to determine whether preconditioning of muscle-derived cells with an antioxidant, sodium ascorbate, can influence the fate of transplanted cells.

METHODS

Autologous transplantation of muscle-derived cells was performed in rabbits. Isolated cells were identified, lipofected with β-galactosidase, preincubated or not with sodium ascorbate, and injected intramuscularly.

RESULTS

Two weeks after autologous transplantation in the edge of a previous muscle defect, donor cells formed multinucleated young myotubes. Pretreatment of cells with sodium ascorbate before injection resulted in a significant increase of donor cells at the injection site 2 weeks after transfer.

CONCLUSIONS

These results show that: (1) preincubation with antioxidant can increase the efficacy of myogenic cell transplantation; and (2) oxidative stress may play a role in elimination of cells after autologous transplantation.

The clinical relevance of cell-based therapy for the treatment of stress urinary incontinence

Stress urinary incontinence is a common disorder affecting the quality of life for millions of women worldwide. Effective surgical procedures involving synthetic permanent meshes exist, but significant short- and long-term complications occur. Cell-based therapy using autologous stem cells or progenitor cells presents an alternative approach, which aims at repairing the anatomical components of the urethral continence mechanism. In vitro expanded progenitor cells isolated from muscle biopsies have been most intensely investigated, and both preclinical trials and a few clinical trials have provided proof of concept for the idea. An initial enthusiasm caused by positive results from early clinical trials has been dampened by the recognition of scientific irregularities. At the same time, the safety issue for cell-based therapy has been highlighted by the appearance of new and comprehensive regulatory demands. The influence on the cost effectiveness, the clinical relevance and the future perspectives of the present clinical approach are discussed.

Regeneration of skeletal muscle

Skeletal muscle has a robust capacity for regeneration following injury. However, few if any effective therapeutic options for volumetric muscle loss are available. Autologous muscle grafts or muscle transposition represent possible salvage procedures for the restoration of mass and function but these approaches have limited success and are plagued by associated donor site morbidity. Cell-based therapies are in their infancy and, to date, have largely focused on hereditary disorders such as Duchenne muscular dystrophy. An unequivocal need exists for regenerative medicine strategies that can enhance or induce de novo formation of functional skeletal muscle as a treatment for congenital absence or traumatic loss of tissue. In this review, the three stages of skeletal muscle regeneration and the potential pitfalls in the development of regenerative medicine strategies for the restoration of functional skeletal muscle in situ are discussed.

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.

Potential applications of gene therapy/transfer to the treatment of lower urinary tract diseases/disorders

Identification of molecular targets for novel therapeutics is a natural consequence of the age of molecular and personalized medicine. How this information is leveraged and applied to the treatment of functional diseases/disorders of the lower urinary tract will determine if this field of medicine can keep pace with technological developments and patient expectations for improved therapies. In this regard, therapeutic improvements for the treatment of lower urinary tract diseases and disorders have been largely incremental over the past 30 years. The goal of this report is to review the evidence pointing toward the enormous potential of gene therapy/transfer to provide a paradigm shift from palliative to curative therapeutic solutions for lower urinary tract diseases/disorders. In fact, it seems clear that gene therapy represents a biotechnology approach particularly suitable to applications in the lower urinary tract. Although much more research is required, ample preclinical evidence already indicates that, for example, gene therapy can favorably impact/alter virtually every aspect of bladder physiology/function. In short, further investigations and continued applications of gene therapy to the treatment of lower urinary tract diseases/disorders seems a prudent step toward potentially marked and more durable therapeutic improvements.

Potential therapeutic applications of muscle-derived mesenchymal stem and progenitor cells

IMPORTANCE OF THE FIELD

Mesenchymal adult stem cells have properties that make them attractive for use in tissue engineering and regenerative medicine. They are inherently plastic, enabling them to differentiate along different lineages, and promote wound healing and regeneration of surrounding tissues by modulating immune and inflammatory responses, promoting angiogenesis and secreting other trophic factors. Unlike embryonic stem cells, clinical uses of mesenchymal stem cells are not encumbered by ethical considerations or legal restrictions.

AREAS COVERED IN THIS REVIEW

We discuss skeletal muscle as a source of mesenchymal stem and progenitor cells by reviewing their biology and current applications in tissue engineering and regenerative medicine. This paper covers literature from the last 5 - 10 years.

WHAT THE READER WILL GAIN

Skeletal muscle is a plentiful source of mesenchymal stem and progenitor cells. This tissue may be obtained via routine biopsy or collection after surgical debridement. We describe the biology of these cells and provide an overview of therapeutic applications currently being developed to take advantage of their regenerative properties.

TAKE HOME MESSAGE

There is potential for stem and progenitor cells derived from skeletal muscle to be incorporated in clinical interventions, either as a cellular therapy to modify the natural history of disease or as a component of engineered tissue constructs that can replace diseased or damaged tissues.

Stem Cells: It's Good To Have Choices

Three types of stem cells, embryonic, adult, and induced pluripotent stem cells, are currently studied by scientists. Barack Obama's presidency has opened the door for stem cell research by revoking statements and orders made during the former President Bush's administration. This provisional period will allow the National Institute of Health to rewrite policies governing how federal funds are distributed for stem cell research. These new regulations will grant more freedom to researchers wishing to use stem cells in their research and challenge them to determine the most appropriate stem cell treatment for a given disorder.

1-year follow-up of autologous muscle-derived stem cell injection pilot study to treat stress urinary incontinence

We hereby report a 1-year follow-up on eight women in the first North America trial in which stress urinary incontinence (SUI) was treated with muscle-derived stem cell injections. Mean and median follow-up in this group was 16.5 and 17 months (range 3-24 months). Improvement in SUI was seen in five of eight women, with one achieving total continence. Onset of improvement was between 3 and 8 months after injection. Cure or improvement continued at a median of 10 months. No serious adverse events were reported.

Bioengineered tissues for urogenital repair in children

The most common congenital abnormalities involve the genitourinary system. These include hypospadias, in which the urethral opening develops in an improper position, and bladder exstrophy, in which the bladder develops on the outer surface of the abdomen. Children with these conditions will require immediate and multiple reconstructive surgeries. Currently, reconstruction may be performed with native nonurologic tissues (skin, gastrointestinal segments, or mucosa), homologous tissues from a donor (cadaver or living donor kidney), heterologous tissues or substances (bovine collagen), or artificial materials (silicone, polyurethane, teflon). However, these materials often lead to complications after reconstruction, either because the implanted tissue is rejected, or because inherently different functional parameters cause a mismatch in the system. For example, replacement of bladder tissue with gastrointestinal segments can be problematic due to the opposite ways in which these two tissues handle solutes-urologic tissue normally excretes material, and gastrointestinal tissue generally absorbs the same materials. This mismatched state can lead to metabolic complications as well as infection and other issues. The replacement of lost or deficient urologic tissues with functionally equivalent ones would improve the outcome of reconstructive surgery in the genitourinary system. This goal may soon be attainable with the use of tissue engineering techniques.

Physiological effects of human muscle-derived stem cell implantation on urethral smooth muscle function

The physiological effects of human muscle-derived stem cell (MDSC) implantation on urethral smooth muscle function were investigated in pudendal nerve-transected nude rats with human MDSC (TM) or saline (TS) injection into the proximal urethra compared with sham-operated, saline-injected nude rats (SS). Leak point pressure (LPP) before and after hexamethonium application, which can block autonomic efferent nerves, and proximal urethral contractile responses to carbachol and phenylephrine in muscle strip study were examined 6 weeks after the implantation. There was no significant difference between the LPPs in SS and TM. Following hexamethonium application, the LPP in TM was, however, significantly decreased compared with SS. The contractile responses to phenylephrine, but not to carbachol, in TM were significantly increased compared with SS and TS. These results suggest that the restorative effects of MDSCs are mediated by autonomic nerves and that increased sensitivity of alpha(1)-adrenoceptors may be related to restore the deficient urethral function.