Adipose-derived stromal cell transplantation for treatment of stress urinary incontinence

We aimed to investigate the application of adipose-derived stromal cells in the treatment of stress urinary incontinence (SUI). Animal models of stress urinary incontinence were established with Sprague-Dawley female rats by complete cutting of the pudendal nerve. Rat adipose-derived stromal cells were isolated, cultured and successfully transplanted into animal models. Effects of stem cell transplantation were evaluated through urodynamic testing and morphologic changes of the urethra and surrounding tissues before and after transplantation. Main urodynamic outcome measures were measured. Intra-bladder pressure and leak point pressure were measured during filling phase. Morphologic examinations were performed. Transplantation of adipose-derived stem cells significantly strengthened local urethral muscle layers and significantly improved the morphology and function of sphincters. Urodynamic testing showed significant improvements in maximum bladder capacity, abdominal leak point pressure, maximum urethral closure pressure, and functional urethral length. Morphologic changes and significant improvement in urination control were consistent over time. It was concluded that periurethral injection of adipose-derived stromal cells improves function of the striated urethral sphincter, resulting in therapeutic effects on SUI. Reconstruction of the pelvic floor through transplantation of adipose-derived cells is a minimally invasive and effective treatment for SUI.     

Treatment of stress urinary incontinence with duloxetine hydrochloride

Currently, there are no approved medications for the treatment of stress urinary incontinence (SUI) in the United States. The effectiveness of duloxetine in the treatment of SUI is linked to its inhibition of presynaptic neuronal reuptake of serotonin and norepinephrine in the central nervous system, resulting in elevated levels of serotonin and norepinephrine in the synaptic cleft. In animal studies, this agent leads to an increase in nerve stimulation to the urethral striated sphincter muscle. A similar mechanism in women is believed to result in stronger urethral contractions, with improved sphincter tone during urine storage and physical stress. In 3 randomized, placebo-controlled clinical trials, patients receiving duloxetine had a statistically significant and clinically relevant reduction in the number of incontinence episodes and a corresponding improvement in quality of life. If this use of duloxetine is approved by the U.S. Food and Drug Administration, as it has been by the European regulatory agencies, it will be the first drug indicated for the treatment of SUI. This pharmacologic therapy is an additional option for women and is likely to become an integral component of patient management.     

Advances in the understanding of sress urinary incontinence and the promise of stem-cell therapy

The middle urethra and external urethral sphincter are the focus in management of stress urinary incontinence, and recent cellular-therapy research suggests a new paradigm in treatment. Cell-based therapies are most often described as using autologous multipotent stem cells procured from bone marrow in procedures that may be painful, require anesthesia, and yield low numbers of mesenchymal stem cells upon processing. In contrast, muscleand adipose-derived stem cells can be obtained easily in large quantities under local anesthesia. Instead of lifting the urethra with a sling or bulking up the urethral sphincter with collagen, we now have the potential to restore function with the use of autologous stem cells.     

The pathophysiology of stress urinary incontinence: a historical perspective

This article provides a historical perspective on the evolution of theories regarding the pathophysiology of stress urinary incontinence (SUI). The progression of these theories has followed the development of the diagnostic technologies that have provided insight into different aspects of urethral dysfunction. The earliest theories tied SUI to anatomic failure of urethral support. Recognition that anatomic failure impacted the interplay of intra-abdominal pressure and the bladder and urethra led to theories focused on the dynamic interaction between the bladder and urethral pressures. Investigators then began to recognize the importance of urethral sphincteric dysfunction. More recently, investigators have attempted to combine the anatomic and functional etiologies into a consolidated theory. These efforts point to a multi-factorial etiology of SUI. Continuing research has provided new insight into the neurophysiology of urethral function, opening new avenues for tailoring therapy for SUI.     

Potential application of stem cells in urogynecology

Recent advances in stem cells therapy and tissue engineering techniques hold great promise for recovery of external urethral sphincter proper functioning and urinary incontinent patients treatment. Adult stem cells (ASCs) may be derived from striated muscles, fat tissue or as mesenchymal cells from bone marrow. These cells can differentiate in functionally normal smooth or striated muscle cells. ASCs injected to external urethral sphincter or bladder neck cause the increase in urethral closure pressure. Favourable findings of trials in animal models and in vitro encouraged to first trials in humans and hold a promising future for the treatment of urinary incontinence.     

Neurophysiology of stress urinary incontinence

Stress urinary incontinence (SUI) involves involuntary leakage of urine in response to abdominal pressure caused by activities such as sneezing and coughing. The condition affects millions of women worldwide, causing physical discomfort as well as social distress and even social isolation. Until recently, SUI was approached by clinicians as a purely anatomic problem requiring behavioral or surgical therapy. Over the past several years, extensive basic and clinical research in the field of neurourology has enhanced our understanding of the complex neural circuitry regulating normal function of the lower urinary tract. As a result, novel concepts have emerged regarding possible neurologic dysfunctions that might underlie the development of SUI, as well as potential novel strategies for pharmacologic therapy. This article reviews the normal neurophysiologic control of lower urinary tract function and considers potential pharmacologic approaches to correcting SUI.     

Stem cell applications for pathologies of the urinary bladder

New stem cell based therapies are undergoing intense research and are widely investigated in clinical fields including the urinary system. The urinary bladder performs critical complex functions that rely on its highly coordinated anatomical composition and multiplex of regulatory mechanisms. Bladder pathologies resulting in severe dysfunction are common clinical encounter and often cause significant impairment of patient’s quality of life. Current surgical and medical interventions to correct urinary dysfunction or to replace an absent or defective bladder are sub-optimal and are associated with notable complications. As a result, stem cell based therapies for the urinary bladder are hoped to offer new venues that could make up for limitations of existing therapies. In this article, we review research efforts that describe the use of different types of stem cells in bladder reconstruction, urinary incontinence and retention disorders. In particular, stress urinary incontinence has been a popular target for stem cell based therapies in reported clinical trials. Furthermore, we discuss the relevance of the cancer stem cell hypothesis to the development of bladder cancer. A key subject that should not be overlooked is the safety and quality of stem cell based therapies introduced to human subjects either in a research or a clinical context.     

Sphincter incontinence: Is regenerative medicine the best alternative to restore urinary or anal sphincter function?

Incontinence is a major public health concern in aging societies. It is caused by age-dependent spontaneous apoptosis of muscle cells in the urinary and fecal sphincters, and is aggravated in women due to birth trauma. Compared to other currently employed invasive surgical management techniques associated with morbidity and recurrence, replacement or regeneration of dysfunctional sphincter through stem cell therapy and tissue engineering techniques hold great promise. This review focuses on the pathophysiological analysis of urinary incontinence and the possible application of muscle-derived-stem cells, satellite cells, chondrocytes and adipose-derived-stem cells in restoring sphincter functions.     

Novel peptide-based biomaterial scaffolds for tissue engineering.

Biomaterial scaffolds are components of cell-laden artificial tissues and transplantable biosensors. Some of the most promising new synthetic biomaterial scaffolds are composed of self-assembling peptides that can be modified to contain biologically active motifs. Peptide-based biomaterials can be fabricated to form two- and three-dimensional structures. Recent studies show that biomaterial promotion of multi-dimensional cell-cell interactions and cell density are crucial for proper cellular differentiation and for subsequent tissue formation. Other refinements in tissue engineering include the use of stem cells, cell pre-selection and growth factor pre-treatment of cells that are used for seeding scaffolds. These cell-culture technologies, combined with improved processes for defining the dimensions of peptide-based scaffolds, might lead to further improvements in tissue engineering. Novel peptide-based biomaterial scaffolds seeded with cells show promise for tissue repair and for other medical applications.     

Role of biomaterials, therapeutic molecules and cells for hepatic tissue engineering

Current liver transplantation strategies face severe shortcomings owing to scarcity of donors, immunogenicity, prohibitive costs and poor survival rates. Due to the lengthy list of patients requiring transplant, high mortality rates are observed during the endless waiting period. Tissue engineering could be an alternative strategy to regenerate the damaged liver and improve the survival and quality of life of the patient. The development of an ideal scaffold for liver tissue engineering depends on the nature of the scaffold, its architecture and the presence of growth factors and recognition motifs. Biomimetic scaffolds can simulate the native extracellular matrix for the culture of hepatocytes to enable them to exhibit their functionality both in vitro and in vivo. This review highlights the physiology and pathophysiology of liver, the current treatment strategies, use of various scaffolds, incorporation of adhesion motifs, growth factors and stem cells that can stabilize and maintain hepatocyte cultures for a long period.     

Preparation of 3D fibrin scaffolds for stem cell culture applications

Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue. A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside. This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis step for the fibrinogen solution to remove citrates that inhibit polymerization. These detailed methods rely on fibrinogen concentrations determined to be optimal for embryonic and induced pluripotent stem cell culture. Other groups have further investigated fibrin scaffolds for a wide range of cell types and applications - demonstrating the versatility of this approach.     

Sodium ascorbate and basic fibroblast growth factor protect muscle-derived cells from H2O2-induced oxidative stress

Engraftment of muscle-derived cells (MDCs) into the urethral sphincter may cure urinary incontinence. However, poor cell survival after injection prompted us to evaluate whether 24-h preincubation with sodium ascorbate (ASC) or basic fibroblast growth factor (bFGF) prior to cell transfer improves the survival of MDCs facing oxidative stress in vitro. We examined MDCs isolated from female rats for the presence of myogenic markers and for the ability to differentiate and respond to growth factors. Isolated cells were positive for desmin, M-cadherin, and myogenin. The fusion index exceeded 29%, and Akt kinase was phosphorylated at Ser473 residue upon exposure to insulin-like growth factor 1 (100 ng/ml). We then autologously transplanted MDCs transfected with lacZ marker gene into urethral wall of the rats; 2 wk later, the urethra and caudal wall of the urinary bladder were harvested from these animals. Serial cryosections revealed that transplanted cells formed multinuclear clusters at injection sites. In addition, we found that the viability of MDCs exposed to a cytotoxic concentration of H2O2 was higher after preincubation with 0.1 mM ASC (2.6-fold), 10 ng/ml bFGF (2.9-fold), or 20 ng/ml bFGF (3.5-fold) than that after exposure to H2O2 only. We conclude that preincubation with ASC or bFGF increases the resistance of MDCs to oxidative stress in vitro. Pretreatment with either agent might be used to enhance survival of MDCs after transplantation.     

Effect of herbal extract mixture on menopausal urinary incontinence in ovariectomized rats

The decline of estrogen production after menopause is contributing factor to urinary incontinence (UI), and particularly stress urinary incontinence (SUI). We determined the preventive effects of herbal extract mixture (HEM) on UI in ovariectomized Sprague Dawley rats. Female 9-weeks old rats were ovariectomized and treated with HEM (2.2, 11, or 55 mg/kg/day) for 8 weeks. The index of urinary bladder weight to body weight in the HEM and non-ovariectomized and non-treated (SHAM) groups were slightly higher than the ovariectomized, non-treated group (OVX). The contraction index of acetylcholine to KCl on detrusor smooth muscle strips in the HEM groups showed a dose-dependent recovery. HEM treatment also significantly improved collagen levels, as shown by Masson trichrome staining, as well as hydroxyproline levels in the urinary bladder. Serum estradiol levels in the HEM groups were higher than the OVX group. In conclusion, HEM increased estradiol levels in serum and improved factors related to urinary incontinence. The improvements in estradiol levels were related to changes in urinary incontinence.     

Applying elastic fibre biology in vascular tissue engineering

For the treatment of vascular disease, the major cause of death in Western society, there is an urgent need for tissue-engineered, biocompatible, small calibre artery substitutes that restore biological function. Vascular tissue engineering of such grafts involves the development of compliant synthetic or biomaterial scaffolds that incorporate vascular cells and extracellular matrix. Elastic fibres are major structural elements of arterial walls that can enhance vascular graft design and patency. In blood vessels, they endow vessels with the critical property of elastic recoil. They also influence vascular cell behaviour through direct interactions and by regulating growth factor activation. This review addresses physiological elastic fibre assembly and contributions to vessel structure and function, and how elastic fibre biology is now being exploited in small diameter vascular graft design.     

New objective measures to quantify stress urinary incontinence in a novel durable animal model of intrinsic sphincter deficiency

Existing animal models of stress urinary incontinence (SUI) are limited because of the low rate of incontinence seen in the animals and to their relatively low durability. In addition, most methods described to measure incontinence are operator-dependent. The aim of this study was to develop a new durable animal model of SUI and establish objective measures to quantify SUI. We subjected female rats to transabdominal urethrolysis. At baseline and at 1, 4, 8, 12, and 24 wk after intervention, animals underwent cystometry and evaluation with abdominal leak point pressure (ALPP). Urethral resistance was evaluated by retrograde urethral perfusion pressure (RUPP). Tissues were obtained for histology and immunohistochemistry. Normal female rats had an average ALPP of 19.4 cmH2O and RUPP of 22.6 cmH2O at baseline. More than 93% of the animals had significantly decreased ALPP and RUPP after the procedure. The mean ALPP and RUPP decreased to 9.8 cmH2O and 11.2 cmH2O, respectively, by 1 wk after urethrolysis. These changes were maintained for up to 24 wk. Changes seen in urethral resistance and ALPP appear to be mediated by apoptosis, decreased neuronal mass, and smooth muscle atrophy. These results indicate that transabdominal urethrolysis is a reliable method of achieving durable decreased urethral resistance in a SUI model. RUPP and ALPP are objective and reproducible methods of assessing urethral resistance. Changes in continence and urethral resistance appear to be mediated by denervation and smooth muscle atrophy, which are seen in both elderly incontinent patients and in patients with intrinsic sphincter dysfunction.     

Stress urinary incontinence in women: diagnosis and medical management

Stress urinary incontinence (SUI) is the most common form of urinary incontinence in women and is associated with high financial, social, and emotional costs. The history and physical examination can identify most patients with a significant stress incontinence component without the need for urodynamic testing. A variety of pharmacologic agents have been used off-label, but an evidence-based pharmacologic treatment has not been readily available. The development of a selective serotonin and norepinephrine reuptake inhibitor will add a potentially useful drug to the primary care physician's practice for treating female patients with SUI. In August 2004, a selective serotonin and norepinephrine reuptake inhibitor, duloxetine, became the first medication approved for the treatment of women with moderate to severe SUI throughout the European Union. As of November 2005, however, duloxetine has not been approved for the treatment of SUI in the United States.     

Association of overactive bladder and stress urinary incontinence in rats with pudendal nerve ligation injury

Approximately one-third of patients with stress urinary incontinence (SUI) also suffer from urgency incontinence, which is one of the major symptoms of overactive bladder (OAB) syndrome. Pudendal nerve injury has been recognized as a possible cause for both SUI and OAB. Therefore, we investigated the effects of pudendal nerve ligation (PNL) on bladder function and urinary continence in female Sprague-Dawley rats. Conscious cystometry with or without capsaicin pretreatment (125 mg/kg sc), leak point pressures (LPPs), contractile responses of bladder muscle strips to carbachol or phenylephrine, and levels of nerve growth factor (NGF) protein and mRNA in the bladder were compared in sham and PNL rats 4 wk after the injury. Urinary frequency detected by a reduction in intercontraction intervals and voided volume was observed in PNL rats compared with sham rats, but it was not seen in PNL rats with capsaicin pretreatment that desensitizes C-fiber-afferent pathways. LPPs in PNL rats were significantly decreased compared with sham rats. The contractile responses of detrusor muscle strips to phenylephrine, but not to carbachol, were significantly increased in PNL rats. The levels of NGF protein and mRNA in the bladder of PNL rats were significantly increased compared with sham rats. These results suggest that pudendal nerve neuropathy induced by PNL may be one of the potential risk factors for OAB, as well as SUI. Somato-visceral cross sensitization between somatic (pudendal) and visceral (bladder) sensory pathways that increases NGF expression and alpha(1)-adrenoceptor-mediated contractility in the bladder may be involved in this pathophysiological mechanism.     

电针阴部神经刺激疗法联合Kegel盆底康复训练对产后压力性尿失禁患者盆底肌力、尿流动力学和生活质量的影响

摘要 目的：探讨电针阴部神经刺激疗法联合Kegel盆底康复训练对产后压力性尿失禁（SUI）患者盆底肌力、尿流动力学和生活质量的影响。方法：选取2019年6月~2021年11月期间于我院就诊的产后SUI患者109例,按照入院就诊奇偶顺序分为两组,其中对照组54例,接受Kegel盆底康复训练,研究组55例,接受电针阴部神经刺激疗法联合Kegel盆底康复训练。对比两组疗效、漏尿量、尿失禁程度、盆底肌力、尿流动力学和生活质量。结果：研究组的临床总有效率高于对照组（P<0.05）。两组治疗后盆底肌肌力各指标（手测肌力和Ⅰ类肌纤维最大值、Ⅱ类肌纤维平均值）均升高,且研究组高于对照组（P<0.05）。两组治疗后漏尿量、尿失禁程度评分均下降,且研究组低于对照组（P<0.05）。两组治疗后尿流动力学相关指标[腹压漏尿点压（AL-PP）、最大尿流率（Qmax）和最大尿道闭合压力（MUCP）]均升高,且研究组高于对照组（P<0.05）。两组治疗后尿失禁生活质量量表（I-QOL）各维度（限制性行为、心理影响、社交活动受限）评分及总分均升高,且研究组高于对照组（P<0.05）。结论：电针阴部神经刺激疗法联合Kegel盆底康复训练可有效改善产后SUI患者的盆底肌肌力和尿失禁情况,减少漏尿量,同时可促进尿流动力学恢复,进而提高患者的生活质量。     

Deleterious effects of endogenous and exogenous testosterone on mesenchymal stem cell VEGF production

Modulating the paracrine effects of bone marrow mesenchymal stem cells (BMSCs) may be important for the treatment of ischemic myocardial tissue. In this regard, endogenous estrogen may enhance BMSC vascular endothelial growth factor (VEGF) production. However, little information exists regarding the effect of testosterone on stem cell function. We hypothesized that 1) endogenous or exogenous estrogen will enhance stem cell production of VEGF and 2) endogenous or exogenous testosterone will inhibit BMSC VEGF production. BMSCs were collected from adult male, female, castrated male, and ovariectomized female rats. One hundred thousand cells were incubated with testosterone (1, 10, or 100 nM) or estrogen (0.15, 1.5, or 15 nM) for 48 h. Cell supernatants were collected, and VEGF was measured by ELISA. BMSCs harvested from castrated males, normal females, and ovariectomized females produced more VEGF compared with normal males. Castration was associated with the highest level (1,018 +/- 98.26 pg/ml) of VEGF production by BMSCs, which was significantly more than that produced by BMSCs harvested from normal male and normal female animals. Exogenous testosterone significantly reduced VEGF production in BMSCs harvested from ovariectomized females in a dose-dependent manner. Exogenous estrogen did not alter BMSC VEGF production. These findings suggest that testosterone may work on BMSCs to decrease protective growth factor production and that effective removal of testosterone's deleterious effects via castration may prove to be beneficial in terms of protective factor production. By manipulating the mechanisms that BMSCs use to produce growth factors, we may be able to engineer stem cells to produce maximum growth factors during therapeutic use.