Myogenic potential of whole bone marrow mesenchymal stem cells in vitro and in vivo for usage in urinary incontinence

Myogenic commitment of human stem cells by myoblasts Co-culture: a static vs. a dynamic approach

An in-vitro model of human bone marrow mesenchymal stem cells (hBM-MSCs) myogenic commitment by synergic effect of a differentiation media coupled with human primary skeletal myoblasts (hSkMs) co-culture was developed adopting both conventional static co-seeding and perfused culture systems. Static co-seeding provided a notable outcome in terms of gene expression with a significant increase of Desmin (141-fold) and Myosin heavy chain II (MYH2, 32-fold) at day 21, clearly detected also by semi-quantitative immunofluorescence. Under perfusion conditions, myogenic induction ability of hSkMs on hBM-MSCs was exerted by paracrine effect with an excellent gene overexpression and immunofluorescence detection of MYH2 protein; furthermore, due to the dynamic cell culture in separate wells, western blot data were acquired confirming a successful cell commitment at day 14. A significant increase of anti-inflammatory cytokine gene expression, including IL-10 and IL-4 (15-fold and 11-fold, respectively) at day 14, with respect to the pro-inflammatory cytokines IL-12A (7-fold at day 21) and IL-1β (1.4-fold at day 7) was also detected during dynamic culture, confirming the immunomodulatory activity of hBM-MSCs along with commitment events. The present study opens interesting perspectives on the use of dynamic culture based on perfusion as a versatile tool to study myogenic events and paracrine cross-talk compared to the simple co-seeding static culture.

Organotypic spinal cord cultures: An <em>in vitro</em> 3D model to preliminary screen treatments for spinal muscular atrophy

Spinal muscular atrophy (SMA) is a severe neuromuscular disease affecting children, due to mutation/deletion of survival motor neuron 1 (SMN1) gene. The lack of functional protein SMN determines motor neuron (MN) degeneration and skeletal muscle atrophy, leading to premature death due to respiratory failure. Nowadays, the Food and Drug Administration approved the administration of three drugs, aiming at increasing the SMN production: although assuring noteworthy results, all these therapies show some non-negligible limitations, making essential the identification of alternative/synergistic therapeutic strategies. To offer a valuable in vitro experimental model for easily performing preliminary screenings of alternative promising treatments, we optimized an organotypic spinal cord culture (derived from murine spinal cord slices), which well recapitulates the pathogenetic features of SMA. Then, to validate the model, we tested the effects of human mesenchymal stem cells (hMSCs) or murine C2C12 cells (a mouse skeletal myoblast cell line) conditioned media: 1/3 of conditioned medium (obtained from either hMSCs or C2C12 cells) was added to the conventional medium of the organotypic culture and maintained for 7 days. Then the slices were fixed and immunoreacted to evaluate the MN survival. In particular we observed that the C2C12 and hMSCs conditioned media positively influenced the MN soma size and the axonal length respectively, without modulating the glial activation. These data suggest that trophic factors released by MSCs or muscular cells can exert beneficial effects, by acting on different targets, and confirm the reliability of the model. Overall, we propose the organotypic spinal cord culture as an excellent tool to preliminarily screen molecules and drugs before moving to in vivo models, in this way partly reducing the use of animals and the costs.

Muscle Regeneration of the Tongue: A review of current clinical and regenerative research strategies

Various abnormalities of the tongue, including cancers, commonly require surgical removal to sequester growth and metastasis. However, even minor resections can affect functional outcomes such as speech and swallowing, thereby reducing quality of life. Surgical resections alone create volumetric muscle loss whereby muscle tissue cannot self-regenerate within the tongue. In these cases, the tongue is reconstructed typically in the form of autologous skin flaps. However, flap reconstruction has many limitations and unfortunately is the primary option for oral and reconstructive surgeons to treat tongue defects. The alternative, but yet undeveloped strategy for tongue reconstruction is regenerative medicine, which widely focuses on building new organs with stem cells. Regenerative medicine has successfully treated many tissues, but research has inadequately addressed the tongue as a vital organ in need of tissue engineering. In this review, we address the current standard for tongue reconstruction, the cellular mechanisms of muscle cell development, and the stem cell studies that have attempted muscle engineering within the tongue. Until now, no review has focused on engineering the tongue with regenerative medicine, which could guide innovative strategies for tongue reconstruction.

Application of adipose-derived, muscle-derived, and co-cultured stem cells for the treatment of stress urinary incontinence in rat models

OBJECTIVES

Based on the recent advancements in cell therapy techniques, we aimed to evaluate the efficacy of transurethral injection of autologous adipose-derived stem cells, muscle-derived stem cells, and co-cultured cells for the rehabilitation of stress urinary incontinence rat models. We hypothesized that the utilization of co-cultured stem cells could result in enhanced therapeutic outcomes attributed to their more comprehensive environment of paracrine factors and cytokines.

METHODS

We performed bilateral pudendal nerve transection surgeries to simulate urinary incontinence in 25 female Wistar rats and employed urodynamic evaluations to confirm the injury. We autologously isolated and cultured adipose-derived mesenchymal stem cells, muscle-derived stem cells, and a mixed culture of the two types, which we subsequently injected into the urethral lumen of the damaged animals. Three weeks after the injection, urodynamic assays, histological staining, and immunohistochemical evaluations were performed to determine the efficacy of the implanted cell cultures in sphincter function improvements or structural modifications.

RESULTS

Histological evaluations suggested a regenerative process in the muscular layer of the external sphincter 3 weeks after the injection. Also, immunohistochemical analysis revealed a thickened periurethral striated muscle layer in the co-cultured group. Postinjection urodynamic analysis indicated that the urethral pressure profile significantly increased in the co-cultured group compared with other groups.

CONCLUSIONS

The outcomes of this investigation indicated that the application of co-cultured adipose-derived and muscle-derived stem cells could be associated with higher therapeutic value in stress urinary incontinence patients compared with singular-cell treatments.

The Dual Nature of Onuf's Nucleus: Neuroanatomical Features and Peculiarities, in Health and Disease

Onuf's nucleus is a small group of neurons located in the ventral horns of the sacral spinal cord. The motor neurons (MNs) of Onuf's nucleus innervate striated voluntary muscles of the pelvic floor and are histologically and biochemically comparable to the other somatic spinal MNs. However, curiously, these neurons also show some autonomic-like features as, for instance, they receive a strong peptidergic innervation. The review provides an overview of the histological, biochemical, metabolic, and gene expression peculiarities of Onuf's nucleus. Moreover, it describes the aging-related pathologies as well as several traumatic and neurodegenerative disorders in which its neurons are involved: indeed, Onuf's nucleus is affected in Parkinson's disease (PD) and Shy-Drager Syndrome (SDS), whereas it is spared in Amyotrophic Lateral Sclerosis (ALS), Spinal Muscular Atrophy (SMA), Duchenne Muscular Dystrophy (DMD). We summarize here the milestone studies that have contributed to clarifying the nature of Onuf's neurons and in understanding what makes them either vulnerable or resistant to damage. Altogether, these works can offer the possibility to develop new therapeutic strategies for counteracting neurodegeneration.

Status, challenges, and future prospects of stem cell therapy in pelvic floor disorders

Pelvic floor disorders (PFDs) represent a group of common and frequently-occurring diseases that seriously affect the life quality of women, generally including stress urinary incontinence and pelvic organ prolapse. Surgery has been used as a treatment for PFD, but almost 30% of patients require subsequent surgery due to a high incidence of postoperative complications and high recurrence rates. Therefore, investigations of new therapeutic strategies are urgently needed. Stem cells possess strong multi-differentiation, self-renewal, immunomodulation, and angiogenesis abilities and they are able to differentiate into various cell types of pelvic floor tissues and thus provide a potential therapeutic approach for PFD. Recently, various studies using different autologous stem cells have achieved promising results by improving the pelvic ligament and muscle regeneration and conferring the tissue elasticity and strength to the damaged tissue in PFD, as well as reduced inflammatory reactions, collagen deposition, and foreign body reaction. However, with relatively high rates of complications such as bladder stone formation and wound infections, further studies are necessary to investigate the role of stem cells as maintainers of tissue homeostasis and modulators in early interventions including therapies using new stem cell sources, exosomes, and tissue-engineering combined with stem cell-based implants, among others. This review describes the types of stem cells and the possible interaction mechanisms in PFD treatment, with the hope of providing more promising stem cell treatment strategies for PFD in the future.

Stem cell applications in regenerative medicine for stress urinary incontinence: A review of effectiveness based on clinical trials

Objective

To evaluate the current state, therapeutic benefit and safety of urethral injection of autologous stem cells for the treatment stress urinary incontinence (SUI).

Materials and methods

A selective database search of PubMed, the Excerpta Medica dataBASE (EMBASE), Cochrane Library and Google Scholar was conducted to validate the effectiveness of stem cell-based therapy. The search included clinical trials published up until 4 January 2020, written in English, and included cohorts of women and men who had received stem cell-based therapy for SUI. The search used the following keywords in various combinations: ‘stem cell therapy’, ‘cell-based therapy for SUI’, ‘regenerative medicine for SUI’, and ‘tissue engineering’. The success rates were assessed according to cough test, urodynamics, pad tests, and International Consultation on Incontinence Questionnaire-Urinary Incontinence. The primary endpoint was continence rate to measure objectively the effect of the treatment.

Results

We identified four clinical trials using local injections of adipose-derived stem cells (ADSCs), 11 trails with muscle-derived stem cells (MDSCs), and two trails with human umbilical cord blood stem cells (HUCBs) and total nucleated cells (TNCs). The median improvement rate of intrinsic sphincter deficiency after ADSCs, MDSCs, TNCs, HUCBs injections were 88%, 77%, 89%, 36% (improvement rate: 1–2 pads) at a mean (range) follow-up of 6 (1–72) months. The cell sources, methods of cell processing, cell number, and implantation techniques differed considerably between studies. Most of the periurethral injections were at the 3, 5, 7, and 9 o’clock positions and for submucosa were at the 4, 6, and 8 o’clock positions. No significant postoperative complications were reported.

Conclusion

Despite many challenges in stem cell-based therapy for treating SUI, it appears to provide, in both male and female patients, acceptable functional results with minimal side-effects and complications. In the future, more clinical trials should be funded in order to optimise stem cell-based therapy and evaluate long-term outcomes.

Abbreviations

ADSC: adipose-derived stem cell; BMSCs: bone marrow-derived mesenchymal stem cell; CLPP: cough leak-point pressure; FPL: functional profile length; HUCB: human umbilical cord blood stem cell; ICIQ-(QOL)(SF)(UI): International Consultation on Incontinence Questionnaire (Quality of life) (-Urinary incontinence Short Form) (-Urinary Incontinence); IIQ-7: Incontinence Impact Questionnaire-short form; I-QOL: Incontinence quality of life questionnaire; ISD: intrinsic urinary sphincter deficiency; MDSC: muscle-derived stem cell; MUCP: maximum urethral closure pressure; NR: not reported; Pdet-max: maximum detrusor pressure; PVR: post-void residual urine volume; Q_max: maximum urinary flow; QOL: quality of life; RP: radical prostatectomy; TNC: total nucleated cell; (S)UI: (stress) urinary incontinence; UDSCs: urine-derived stem cells; UTUS: upper tract ultrasonography; VLPP: Valsalva leak-point pressure

Hot-Band Anti-Stokes Fluorescence Properties of Alexa Fluor 568

Hot-band absorption and anti-Stokes emission properties of an organic fluorescent dye, Alexa Fluor 568, were characterized and compared with those of Rhodamine 101. The comparison of the properties (e.g., quantum efficiency, spectral distribution, thermal properties, and fluorescence lifetime) between the two dyes confirms that both dyes undergo the same process when excited in the red spectral region. Possible undesirable crosstalk effects and applications in dSTORM microscopy were demonstrated and discussed.

Regenerative medicine and injection therapies in stress urinary incontinence

Stress urinary incontinence (SUI) is a common and bothersome condition. Anti-incontinence surgery has high cure rates, but concerns about mesh tapes have resulted in the resurgence of surgical procedures that involve increased abdominopelvic dissection and morbidity. Injection therapy with urethral bulking agents or stem cell formulations have been developed as minimally invasive alternatives. Many synthetic and biological bulking agents have been trialled, but several have been discontinued owing to safety concerns. The use of Macroplastique and Contigen has the largest evidence base, but, overall, success rates seem to be similar between the various agents and positive outcomes are poorly sustained for more than 6 months. Furthermore, subjective cure rates, although initially high, also deteriorate over time. The available data consistently demonstrate manifestly poorer outcomes for injection therapies than for surgery. Stem cell treatments are thought to functionally regenerate the urethral sphincter in patients with suspected intrinsic sphincter deficiency. Autologous adipose and muscle-derived stem cells seem to be the intuitive cell source, as they are comparatively abundant, can be harvested and cause minimal donor site morbidity. To date, only a few small clinical studies have been reported and most data are derived from animal models. The success rates of stem cell injection therapies seem to be comparable with those of bulking agents.

Decellularized extracellular matrix gelloids support mesenchymal stem cell growth and function in vitro

Volumetric muscle loss (VML) injuries are irrecoverable due to a significant loss of regenerative elements, persistent inflammation, extensive fibrosis, and functional impairment. When used in isolation, previous stem cell and biomaterial-based therapies have failed to regenerate skeletal muscle at clinically relevant levels. The extracellular matrix (ECM) microenvironment is crucial for the viability, stemness, and differentiation of stem cells. Decellularized-ECM (D-ECM) scaffolds are at the forefront of ongoing research to develop a viable therapy for VML. Due to the retention of key ECM components, D-ECM scaffolds provide an excellent substrate for the adhesion and migration of several cell types. Mesenchymal stem cells (MSCs) possess regenerative and immunomodulatory properties and are currently under investigation in clinical trials for a wide range of medical conditions. However, a major limitation to the use of MSCs in clinical applications is their poor viability at the site of transplantation. In this study, we have fabricated spherical scaffolds composed of gelatin and skeletal muscle D-ECM for the adhesion and delivery of MSCs to the site of VML injury. These spherical scaffolds termed "gelloids" supported MSC survival, expansion, trophic factor secretion, immunomodulation, and myogenic protein expression in vitro. Future studies would determine the therapeutic efficacy of this approach in a murine model of VML injury.

Mesenchymal Stem Cells for Spinal Cord Injury: Current Options, Limitations, and Future of Cell Therapy

Spinal cord injury (SCI) constitutes an inestimable public health issue. The most crucial phase in the pathophysiological process of SCI concerns the well-known secondary injury, which is the uncontrolled and destructive cascade occurring later with aberrant molecular signaling, inflammation, vascular changes, and secondary cellular dysfunctions. The use of mesenchymal stem cells (MSCs) represents one of the most important and promising tested strategies. Their appeal, among the other sources and types of stem cells, increased because of their ease of isolation/preservation and their properties. Nevertheless, encouraging promise from preclinical studies was followed by weak and conflicting results in clinical trials. In this review, the therapeutic role of MSCs is discussed, together with their properties, application, limitations, and future perspectives.

Efficiency of mesenchymal stem cells in treatment of urinary incontinence: a systematic review on animal models

AIM

In recent years, the administration of stem cells has been considered a new option for treatment of urinary incontinence (UI). In the present study, the efficiency of mesenchymal stem cell (MSC) transplantation in the treatment of UI was evaluated.

METHODS

Combinations of the key words 'mesenchymal stem cells', 'MSCs', 'urinary incontinence', 'urethral sphincter' and 'involuntary urination' were searched in PubMed and Science Direct databases. Following application of exclusion criteria to the 1946 papers obtained and review and duplicate articles were removed, 23 articles were considered further. The search was limited to the animal model studies.

RESULTS

The data obtained from the evaluation of different studies indicated that the injected MSCs play an important role in the neovascularization and the recovery of muscle cells in UI models through the paracrine process.

CONCLUSION

The obtained data suggested that further trials are needed to be focused on clinical phase of MSC therapy on the patients affected by UI.

Stem Cells for Urinary Incontinence: Functional Differentiation or Cytokine Effects?

Minimally invasive stem cell therapy for stress urinary incontinence may provide an effective nonsurgical treatment for this common condition. Clinical trials of periurethral stem cell injection have been under way, and basic science research has demonstrated the efficacy of both local and systemic stem cell therapies. Results differ as to whether stem cells have a therapeutic effect by differentiating into permanent, functional tissues or exert benefits through a transient presence and the secretion of regenerative factors. This review explores the fate of therapeutic stem cells for stress urinary incontinence and how this may relate to their mechanism of action.

In vivo imaging system for explants analysis-A new approach for assessment of cell transplantation effects in large animal models

Introduction

Despite spectacular progress in cellular transplantology, there are still many concerns about the fate of transplanted cells. More preclinical studies are needed, especially on large animal models, to bridge the translational gap between basic research and the clinic. Herein, we propose a novel approach in analysis of cell transplantation effects in large animals explants using in vivo imaging system (IVIS®) or similar equipment.

Material and methods

In the in vitro experiment cells labeled with fluorescent membrane dyes: DID (far red) or PKH26 (orange) were visualized with IVIS®. The correlation between the fluorescence signal and cell number with or without addition of minced muscle tissue was calculated. In the ex vivo study urethras obtained from goats after intraurethral cells (n = 9) or PBS (n = 4) injections were divided into 0.5 cm cross-slices and analyzed by using IVIS®. Automatic algorithm followed or not by manual setup was used to separate specific dye signal from tissue autofluorescence. The results were verified by systematic microscopic analysis of standard 10 μm specimens prepared from slices before and after immunohistochemical staining. Comparison of obtained data was performed using diagnostic test function.

Results

Fluorescence signal strength in IVIS® was directly proportional to the number of cells regardless of the dye used and detectable for minimum 0.25x10⁶ of cells. DID-derived signal was much less affected by the background signal in comparison to PKH26 in in vitro test. Using the IVIS® to scan explants in defined arrangement resulted in precise localization of DID but not PKH26 positive spots. Microscopic analysis of histological specimens confirmed the specificity (89%) and sensitivity (80%) of IVIS® assessment relative to DID dye. The procedure enabled successful immunohistochemical staining of specimens derived from analyzed slices.

Conclusions

The IVIS® system under appropriate conditions of visualization and analysis can be used as a method for ex vivo evaluation of cell transplantation effects. Presented protocol allows for evaluation of cell delivery precision rate, enables semi-quantitative assessment of signal, preselects material for further analysis without interfering with the tissue properties. Far red dyes are appropriate fluorophores to cell labeling for this application.

Cell therapy for stress urinary incontinence: Present-day frontiers

Stress urinary incontinence (SUI) significantly diminishes the quality of patients' lives. Currently available surgical and nonsurgical therapies remain far from ideal. At present, advances in cellular technologies have stirred growing interest in the use of autologous cell treatments aimed to regain urinary control. The objective was to conduct a review of the literature and analyse preclinical and clinical studies dedicated to various cell therapies for SUI, assessing their effectiveness, safety, and future prospects. A systematic literature search in PubMed was conducted using the following key terms: "stem," "cell," "stress," "urinary," and "incontinence." A total of 32 preclinical studies and 15 clinical studies published between 1946 and December 2014 were included in the review. Most preclinical trials have used muscle-derived stem cells and adipose-derived stem cells. However, at present, the application of other types of cells, such as human amniotic fluid stem muscle-derived progenitor cells and bone marrow mesenchymal stromal cells, is becoming more extensive. While the evidence shows that these therapies are effective and safe, further work is required to standardize surgical techniques, as well as to identify indications for their use, doses and number of doses. Future research will have to focus on clinical applications of cell therapies; namely, it will have to determine indications for their use, doses of cells, optimal surgical techniques and methods, attractive cell sources, as well as to develop clinically relevant animal models and make inroads into understanding the mechanisms of SUI improvement by cell therapies.

Bone marrow mesenchymal stem cell therapy for voiding dysfunction

Lower urinary tract symptoms can significantly impact quality of life. Current standard treatments are not always effective and are associated with complications and side effects. The discovery of stem cells led to research into cell-based therapies for treatment of disorders of voiding dysfunction. Bone marrow mesenchymal stem cells are particularly promising given their ability to differentiate into a variety of cell types. Recent studies have investigated bone marrow stem cells to treat a number of functional voiding pathologies including bladder outlet obstruction, neurogenic bladder, and stress urinary incontinence. Experiments in tissue regeneration have also attempted to create artificial bladders and urethras. The purpose of this article is to critically review the literature regarding the use of bone marrow mesenchymal stem cells in treatment of voiding dysfunction.

Myogenic differentiation potential of human tonsil-derived mesenchymal stem cells and their potential for use to promote skeletal muscle regeneration

Stem cells are regarded as an important source of cells which may be used to promote the regeneration of skeletal muscle (SKM) which has been damaged due to defects in the organization of muscle tissue caused by congenital diseases, trauma or tumor removal. In particular, mesenchymal stem cells (MSCs), which require less invasive harvesting techniques, represent a valuable source of cells for stem cell therapy. In the present study, we demonstrated that human tonsil-derived MSCs (T-MSCs) may differentiate into myogenic cells in vitro and that the transplantation of myoblasts and myocytes generated from human T-MSCs mediates the recovery of muscle function in vivo. In order to induce myogenic differentiation, the T-MSC-derived spheres were cultured in Dulbecco's modified Eagle's medium/nutrient mixture F-12 (DMEM/F-12) supplemented with 1 ng/ml transforming growth factor-β, non-essential amino acids and insulin-transferrin-selenium for 4 days followed by culture in myogenic induction medium [low-glucose DMEM containing 2% fetal bovine serum (FBS) and 10 ng/ml insulin-like growth factor 1 (IGF1)] for 14 days. The T-MSCs sequentially differentiated into myoblasts and skeletal myocytes, as evidenced by the increased expression of skeletal myogenesis-related markers [including α-actinin, troponin I type 1 (TNNI1) and myogenin] and the formation of myotubes in vitro. The in situ transplantation of T-MSCs into mice with a partial myectomy of the right gastrocnemius muscle enhanced muscle function, as demonstrated by gait assessment (footprint analysis), and restored the shape of SKM without forming teratomas. Thus, T-MSCs may differentiate into myogenic cells and effectively regenerate SKM following injury. These results demonstrate the therapeutic potential of T-MSCs to promote SKM regeneration following injury.

Stem Cell Therapy for Treatment of Stress Urinary Incontinence: The Current Status and Challenges

Stress urinary incontinence (SUI) is a common urinary system disease that mostly affects women. Current treatments still do not solve the critical problem of urethral sphincter dysfunction. In recent years, there have been major developments in techniques to obtain, culture, and characterize autologous stem cells as well as many studies describing their applications for the treatment of SUI. In this paper, we review recent publications and clinical trials investigating the applications of several stem cell types as potential treatments for SUI and the underlying challenges of such therapy.

Viability and MR detectability of iron labeled mesenchymal stem cells used for endoscopic injection into the porcine urethral sphincter

Direct stem cell therapies for functionally impaired tissue require a sufficient number of cells in the target region and a method for verifying the fate of the cells in the subsequent time course. In vivo MRI of iron labeled mesenchymal stem cells has been suggested to comply with these requirements. The study was conducted to evaluate proliferation, migration, differentiation and adhesion effects as well as the obtained iron load of an iron labeling strategy for mesenchymal stem cells. After injection into the porcine urethral sphincter, the labeled cells were monitored for up to six months using MRI. Mesenchymal stem cells were labeled with ferucarbotran (60/100/200 µg/mL) and ferumoxide (200 µg/mL) for the analysis of migration and viability. Phantom MR measurements were made to evaluate effects of iron labeling. For short and long term studies, the iron labeled cells were injected into the porcine urethral sphincter and monitored by MRI. High resolution anatomical images of the porcine urethral sphincter were applied for detection of the iron particles with a turbo-spin-echo sequence and a gradient-echo sequence with multiple TE values. The MR images were then compared with histological staining. The analysis of cell function after iron labeling showed no effects on proliferation or differentiation of the cells. Although the adherence increases with higher iron dose, the ability to migrate decreases as a presumed effect of iron labeling. The iron labeled mesenchymal stem cells were detectable in vivo in MRI and histological staining even six months after injection. Labeling with iron particles and subsequent evaluation with highly resolved three dimensional data acquisition allows sensitive tracking of cells injected into the porcine urethral sphincter for several months without substantial biological effects on mesenchymal stem cells.

Human Adipose Stem Cells: From Bench to Bedside

Stem cell-based therapies for repair and regeneration of different tissues are becoming more important in the treatment of several diseases. Adult stem cells currently symbolize the most available source of cell progenitors for tissue engineering and repair and can be harvested using minimally invasive procedures. Moreover, mesenchymal stem cells (MSCs), the most widely used stem cells in stem cell-based therapies, are multipotent progenitors, with capability to differentiate into cartilage, bone, connective, muscle, and adipose tissue. So far, bone marrow has been regarded as the main source of MSCs. To date, human adult adipose tissue may be the best suitable alternative source of MSCs. Adipose stem cells (ASCs) can be largely extracted from subcutaneous human adult adipose tissue. A large number of studies show that adipose tissue contains a biologically and clinically interesting heterogeneous cell population called stromal vascular fraction (SVF). The SVF may be employed directly or cultured for selection and expansion of an adherent population, so called adipose-derived stem cells (ASCs). In recent years, literature based on data related to SVF cells and ASCs has augmented considerably: These studies have demonstrated the efficacy and safety of SVF cells and ASCs in vivo in animal models. On the basis of these observations, in several countries, various clinical trials involving SVF cells and ASCs have been permitted. This review aims at summarizing data regarding either ASCs cellular biology or ASCs-based clinical trials and at discussing the possible future clinical translation of ASCs and their potentiality in cell-based tissue engineering.

Cell Therapy for Stress Urinary Incontinence

Urinary incontinence (UI) is the involuntary loss of urine and is a common condition in middle-aged and elderly women and men. Stress urinary incontinence (SUI) is caused by leakage of urine when coughing, sneezing, laughing, lifting, and exercise, even standing leads to increased intra-abdominal pressure. Other types of UI also exist such as urge incontinence (also called overactive bladder), which is a strong and unexpected sudden urge to urinate, mixed forms of UI that result in symptoms of both urge and stress incontinence, and functional incontinence caused by reduced mobility, cognitive impairment, or neuromuscular limitations that impair mobility or dexterity. However, for many SUI patients, there is significant loss of urethral sphincter muscle due to degeneration of tissue, the strain and trauma of pregnancy and childbirth, or injury acquired during surgery. Hence, for individuals with SUI, a cell-based therapeutic approach to regenerate the sphincter muscle offers the advantage of treating the cause rather than the symptoms. We discuss current clinically relevant cell therapy approaches for regeneration of the external urethral sphincter (striated muscle), internal urethral sphincter (smooth muscle), the neuromuscular synapse, and blood supply. The use of mesenchymal stromal/stem cells is a major step in the right direction, but they may not be enough for regeneration of all components of the urethral sphincter. Inclusion of other cell types or biomaterials may also be necessary to enhance integration and survival of the transplanted cells.

Mesenchymal stromal cells for sphincter regeneration

Stress urinary incontinence (SUI), defined as the involuntary loss of considerable amounts of urine during increased abdominal pressure (exertion, effort, sneezing, coughing, etc.), is a severe problem to the individuals affected and a significant medical, social and economic challenge. SUI is associated with pelvic floor debility, absence of detrusor contraction, or a loss of control over the sphincter muscle apparatus. The pathology includes an increasing loss of muscle cells, replacement of muscular tissue with fibrous tissue, and general aging associated processes of the sphincter complex. When current therapies fail to cure or improve SUI, application of regeneration-competent cells may be an alternative therapeutic option. Here we discuss different aspects of the biology of mesenchymal stromal cells, which are relevant to their clinical applications and for regenerating the sphincter complex. However, there are reports in favor of and against cell-based therapies. We therefore summarize the potential and the risks of cell-based therapies for the treatment of SUI.

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.

Urethral dysfunction in female mice with estrogen receptor β deficiency

Estrogen has various regulatory functions in the growth, development, and differentiation of the female urogenital system. This study investigated the roles of ERβ in stress urinary incontinence (SUI). Wild-type (ERβ^+/+) and knockout (ERβ^−/−) female mice were generated (aged 6–8 weeks, n = 6) and urethral function and protein expression were measured. Leak point pressures (LPP) and maximum urethral closure pressure (MUCP) were assessed in mice under urethane anesthesia. After the measurements, the urethras were removed for proteomic analysis using label-free quantitative proteomics by nano-liquid chromatography–mass spectrometry (LC-MS/MS) analysis. The interaction between these proteins was further analysed using MetaCore. Lastly, Western blot was used to confirm the candidate proteins. Compared with the ERβ^+/+ group, the LPP and MUCP values of the ERβ^−/− group were significantly decreased. Additionally, we identified 85 differentially expressed proteins in the urethra of ERβ^−/− female mice; 57 proteins were up-regulated and 28 were down-regulated. The majority of the ERβ knockout-modified proteins were involved in cell-matrix adhesion, metabolism, immune response, signal transduction, nuclear receptor translational regelation, and muscle contraction and development. Western blot confirmed the up-regulation of myosin and collagen in urethra. By contrast, elastin was down-regulated in the ERβ^−/− mice. This study is the first study to estimate protein expression changes in urethras from ERβ^−/− female mice. These changes could be related to the molecular mechanism of ERβ in SUI.

Whole bone marrow cell culture: A convenient protocol for the in vitro expansion of endothelial progenitor cells

The number and function of endothelial progenitor cells (EPCs) may be a predictive factor for the severity and outcome of cardiovascular disease. However, the manipulation of bone marrow mononuclear cell (BMMC) cultures for EPCs is an elaborate and difficult procedure in small experimental animals. The present study aimed to assess the feasibility of whole bone marrow cell (WBMC) culture for expanding EPCs in small experimental animals. C57BL/6 mice (age, 3–4 weeks; weight, 9.47±0.76 g) were used as the experimental animals, and WBMCs were isolated from the femora and tibiae and cultured in endothelial cell growth medium-2. A BMMC culture for EPCs was used as a control. EPC growth, phenotype and functions were assessed in vitro and in vivo. The results demonstrated that EPCs were easily obtained from a WBMC culture in vitro. The cells exhibited similar growth and biological characteristics when compared with the EPCs derived from the traditional BMMC culture system. Thus, the cells were able to simultaneously bind to lectin and cause phagocytosis of acetylated-low density lipoproteins. In addition, the cells exhibited high expression levels of cluster of differentiation 34 and fetal liver kinase 1, and possessed similar functional properties to BMMC-derived EPCs, including vascular network formation, proliferation, adhesion and migration abilities in vitro. Thus, WBMC-derived EPCs can improve the outcome of pulmonary vascular disease when transplanted into a monocrotaline-induced pulmonary hypertension mouse model. The results of the present study indicated that the WBMC culture system is a more convenient and effective method of obtaining and expanding EPCs compared with BMMC culture, with the advantage of a simplified procedure.

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.

The effect of urine-derived stem cells expressing VEGF loaded in collagen hydrogels on myogenesis and innervation following after subcutaneous implantation in nude mice

Impairment of sphincter muscles or their neural and vascular support leads to stress urinary incontinence. The aim of this study was to determine the role of urine-derived stem cells (USCs) over-expressing vascular endothelial growth factor (VEGF) in collagen-I gel on angiogenesis, cell survival, cell growth, myogenic phenotype differentiation of the implanted cells and innervations following implantation in vivo. USCs were infected with adenovirus containing the human VEGF165 and green fluorescent protein genes. A total of 5 × 10(6) cells, USCs alone, or plus endothelial cells or human skeletal myoblasts (as control) suspended in collagen-I gel were subcutaneously implanted into nude mice. Extensive vascularization and more implanted cells was noted in VEGF-expressing USCs groups compared to the non-VEGF groups in vivo. Numbers of the cells displaying endothelial markers (CD 31 and von Willebrand's factor) and myogenic markers (myf-5, MyoD and desmin), and regenerated nerve fibers displaying neural markers (S-100, GFAP and neurofilament) significantly increased in the grafts of VEGF-expressing USCs. Improved angiogenesis by VEGF-expressing USCs enhanced grafted cell survival, recruited the resident cells and promoted myogenic phenotype differentiation of USCs and innervation. This approach has important clinical implications for the development of cell therapies for the correction of stress urinary incontinence.

Functional recovery of urethra by plasmid DNA-loaded injectable agent for the treatment of urinary incontinence

Stress urinary incontinence (SUI) is an embarrassing problem affecting a large number of women and interfering with their quality of life. The injury or weakness of urethral supporting tissues by childbirth and aging has been considered as key factors in the development of the SUI. In this study, plasmid DNA (pDNA; encoding for bFGF) complex-loaded poly(DL-lactic-co-glycolic acid) (PLGA)/Pluronic F127 mixture dispersed with polycaprolactone (PCL) microspheres was prepared as an injectable bioactive bulking agent that may provide bulking effect (by PCL microspheres) and allow stimulation of the defect tissues around urethra (by synthesis of bFGF from cells or tissues transfected by the pDNA complex) for the effective treatment of SUI. From in vitro experiments, the pDNA complex incorporated in the bulking agent was released in a sustained manner over 84 days (≥80% of the initial loading amount). The pDNA complex was effectively transfected into fibroblasts and the cells were continuously producing the target protein, bFGF. From the in vivo study using hairless mice and Sprague-Dawley rats, it was confirmed that the pDNA complex released from the bulking agent is transfected into surrounding cells/tissue, and the cells/tissues synthesize sufficient bFGF to regenerate smooth muscle with biological function around the urethra. Basis on these results, the pDNA (encoding for bFGF) complex-loaded PLGA/Pluronic F127 mixture dispersed with PCL microspheres can be a promising bioactive bulking agent system for the fundamental cure of SUI.

Evidence for bone marrow adult stem cell plasticity: properties, molecular mechanisms, negative aspects, and clinical applications of hematopoietic and mesenchymal stem cells transdifferentiation

In contrast to the pluripotent embryonic stem cells (ESCs) which are able to give rise to all cell types of the body, mammalian adult stem cells (ASCs) appeared to be more limited in their differentiation potential and to be committed to their tissue of origin. Recently, surprising new findings have contradicted central dogmas of commitment of ASCs by showing their plasticity to differentiate across tissue lineage boundaries, irrespective of classical germ layer designations. The present paper supports the plasticity of the bone marrow stem cells (BMSCs), bringing the most striking and the latest evidences of the transdifferentiation properties of the bone marrow hematopoietic and mesenchymal stem cells (BMHSCs, and BMMSCs), the two BM populations of ASCs better characterized. In addition, we report the possible mechanisms that may explain these events, outlining the clinical importance of these phenomena and the relative problems.