The use of autologous skeletal muscle progenitor cells for adjunctive treatment of presumptive urethral sphincter mechanism incompetence in female dogs.

BACKGROUND: Urethral sphincter mechanism incompetence (USMI) is a common problem in female dogs, but some dogs fail to achieve continence with standard treatment. Urethral submucosal injection of autologous skeletal muscle progenitor cells (skMPCs) previously has been shown to restore urethral function in a canine model of USMI. HYPOTHESIS/OBJECTIVE: To determine if urethral submucosal injection of skMPC alters continence in dogs with USMI that had previously failed standard medical management. We hypothesized that the injections would lead to improved continence. ANIMALS: Fifteen client-owned dogs with USMI that had failed standard medical management. METHODS: Dogs were prospectively enrolled into a single-armed clinical trial. Once enrolled, a triceps muscle of each dog was biopsied; the tissue specimens were digested, cultured, and expanded to 100 million cells before injection into the urethral submucosa using a surgical approach. Continence was assessed at baseline and 3, 6, 12, and 24 months post-injection using continence scores and urethral pressure profilometry. RESULTS: Median continence scores increased significantly from baseline at 3, 6, 12, and 24 months. Increases were seen in 14 of 15 dogs with 7, 6 or 1 dog achieving scores of 5, 4 or 3, respectively. Additional medication was required to achieve continence in all but 2 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Urethral submucosal injection of skMPC can be used adjunctively to improve continence in dogs with difficult to manage USMI. The procedure is labor intensive but well tolerated; most dogs will require continued medication to remain continent.

Regenerative medicine for anal incontinence: a review of regenerative therapies beyond cells.

INTRODUCTION AND HYPOTHESIS: Current treatment modalities for anal sphincter injuries are ineffective for many patients, prompting research into restorative and regenerative therapies. Although cellular therapy with stem cells and progenitor cells show promise in animal models with short-term improvement, there are additional regenerative approaches that can augment or replace cellular therapies for anal sphincter injuries. The purpose of this article is to review the current knowledge of cellular therapies for anal sphincter injuries and discusses the use of other regenerative therapies including cytokine therapy with CXCL12. METHODS: A literature search was performed to search for articles on cellular therapy and cytokine therapy for anal sphincter injuries and anal incontinence. RESULTS: The article search identified 337 articles from which 33 articles were included. An additional 12 referenced articles were included as well as 23 articles providing background information. Cellular therapy has shown positive results for treating anal sphincter injuries and anal incontinence in vitro and in one clinical trial. However, cellular therapy has disadvantages such as the source and processing of stem cells and progenitor cells. CXCL12 does not have such issues while showing promising in vitro results for treating anal sphincter injuries. Additionally, electrical stimulation and extracorporeal shock wave therapy are potential regenerative medicine adjuncts for anal sphincter injuries. A vision for future research and clinical applications of regenerative medicine for anal sphincter deficiencies is provided. CONCLUSION: There are viable regenerative medicine therapies for anal sphincter injuries beyond cellular therapy. CXCL12 shows promise as a focus of therapeutic research in this field.

New concepts in regenerative medicine approaches to the treatment of female stress urinary incontinence.

PURPOSE OF REVIEW: Update on recent regenerative medicine approaches to the treatment of stress urinary incontinence (SUI) caused by intrinsic sphincter deficiency (ISD). RECENT FINDINGS: In the treatment of female SUI/ISD, results using different types of cellular therapy have been disappointing, and new approaches are desirable. To advance our regenerative medicine approaches to SUI/ISD, it is critical to utilize animal models that best parallel the pathophysiology of this disease in women. Many current animal models mimic acute SUI/ISD. However, SUI/ISD in women is usually a chronic condition resulting from previous muscle and nerve sphincter damage during parturition or muscle loss during aging. Similar to women, a nonhuman primate (NHP) model of chronic SUI/ISD has demonstrated only modest response to cell therapy. However, treatment with stromal cell-derived factor 1 (SDF1), also known as C-X-C motif chemokine 12 (CXCL12) restored continence in this model. SUMMARY: As a potential therapeutic approach, the use of a well characterized chemokine, such as CXCL12, may by-pass the lengthy and expensive process of cell isolation, expansion, and injection. Recent findings in this new NHP model of chronic SUI/ISD may open up the field for noncell-based treatments.

Nonhuman primate model of persistent erectile and urinary dysfunction following radical prostatectomy: Feasibility of minimally invasive therapy.

OBJECTIVE: Persistent urinary incontinence (UI) and/or erectile dysfunction (ED) occur in 30-50% of post-radical prostatectomy patients regardless of nerve sparing approaches. Identification of potential treatment options for these patients will require testing in an animal model that develops these chronic conditions. The objective was to characterize a nonhuman primate (NHP) model of persistent post-prostatectomy ED and UI and then test the feasibility of periurethral injection of the chemokine CXCL-12. METHODS: Ten adult male cynomolgus monkeys were used. Two were used for study of normal male nonhuman primate genitourinary anatomy. Five were used for measures of sexual behavior, peak intra-corporal pressure (ICP), abdominal leak point pressures (ALPP) 3 and 6-months post open radical prostatectomy (ORP). Three additional ORP animals received ultrasound-guided peri-urethral injection of chemokine CXCL12 6 weeks after ORP, and UI/ED evaluated for up to 3 months. RESULTS: The anatomy, innervation, and vascular supply to the prostate and surrounding tissues of these male NHPs are substantially similar to those of human beings. ORP resulted in complete removal of the prostate gland along with both neurovascular bundles and seminal vesicles while permitting stable restoration of vesico-urethral patency. ORP produced sustained (6 months) decreases in ALPP, ICP's, and sexual function. Transurethral injection of chemokine CXCL12 was feasible and had beneficial effects on erectile and urinary function. CONCLUSIONS: ORP in NHPs produced persistent erectile and urinary tract dysfunction. Periurethral injection of CXCL-12 was feasible and improved both urinary incontinence and erectile dysfunction and suggests that this model can be used to test new approaches for both conditions.

Determinates of muscle precursor cell therapy efficacy in a nonhuman primate model of intrinsic urinary sphincter deficiency.

BACKGROUND: Cell therapy for intrinsic urinary sphincter deficiency (ISD) in women has been moderately effective, and improvements are needed. To improve treatment efficacy, it is important to better understand determinates of cell efficacy in the different patient cohorts. We have reported that in nonhuman primates the chronicity of ISD may affect cell efficacy, but additional factors (age, psychosocial stress, hormone status, body weight) can be associated with many disease/treatment outcomes in women - and these factors are the focus of this study. METHODS: Adult female cynomolgus monkeys were divided into groups: (1) younger (n = 10, 5-8 years of age) versus older (n = 10, 13-18 years of age); (2) age-matched/socially subordinate (n = 15) versus socially dominant (n = 15); and (3) age-matched lower body weight (n = 6) versus higher body weight (n = 6). Autologous skeletal muscle precursor cells (skMPCs, 5 million) were injected into the urinary sphincter 6 weeks after a surgically induced ISD procedure. Resting and pudendal nerve-stimulated maximal urethral pressures (MUP) were measured before, and 3 and 6 months post-skMPC treatment and urinary sphincter muscle/collagen content within the sphincter complex was measured by quantitative histology 6 months posttreatment. RESULTS: Efficacy of skMPCs on MUP and sphincter muscle/collagen ratios are affected by age (average 40% reduction in efficacy, p < 0.05 vs. younger NHPs), social stress (average 30% reduction in efficacy, p < 0.05 vs. socially dominant) and body weight/fasting glucose concentrations (average 35% reduction in efficacy, p < 0.05 vs. lower body weight). CONCLUSION: Multiple factors (age, stress-induced dysmenorrhea, and body weight) affect the efficacy of cell therapy to restore structure and function in the urinary sphincter complex in NHPs with ISD. Consideration of, and alternatives for, these patient cohorts should be considered.

Regenerative pharmacology: recent developments and future perspectives.

This review focuses on the current status of research that utilizes the application of pharmacological sciences to accelerate, optimize and characterize the development, maturation and function of bioengineered and regenerating tissues. These regenerative pharmacologic approaches have been applied to diseases of the urogenital tract, the heart, the brain, the musculoskeletal system and diabetes. Approaches have included the use of growth factors (such as VEGF and chemokines (stromal-derived factor - CXCL12) to mobilize cell to the sights of tissue loss or damage. The promise of this approach is to bypass the lengthy and expensive processes of cell isolation and implant fabrication to stimulate the body to heal itself with its own tissue regenerative pathways.

Effects of hormone therapy and dietary soy on myocardial ischemia/reperfusion injury in ovariectomized atherosclerotic monkeys.

OBJECTIVE: Hormone therapy (HT) and dietary soy (Soy) inhibit myocardial ischemia/reperfusion (I/R) injury in nonatherosclerotic animals. The aim of this study was to determine their independent and interactive effects on I/R in monkeys previously fed an atherogenic diet for 15 months. DESIGN: Ovariectomized atherosclerotic monkeys (n = 40) were divided into one of four dietary treatment groups: (1) casein as the protein source, (2) casein and added HT (the equivalent of 5 mug ethinyl estradiol + 1 mg norethindrone acetate daily), (3) Soy protein providing 141 mg total isoflavones daily, or (4) Soy + HT. After 12 months monkeys were anesthetized, and their left anterior descending coronary artery was occluded for 1 hour and reperfused for 4 hours. Infarct size was the percentage of the area at risk not staining with triphenyltetrazolium chloride. Additional measures were myocardial blood flow, stroke volume, coronary output, myeloperoxidase, and malondialdehyde. RESULTS: There was an interactive negative effect of HT + Soy to increase infarct size from approximately 30% (in other groups) to 55% (P = 0.0004). Additionally, there were negative main effects of Soy on blood flow, coronary output, and stroke volume during I/R (all P values <0.05). There were no effects of treatment on either myeloperoxidase or malondialdehyde. CONCLUSIONS: Neither HT nor Soy had beneficial effects, whereas their combination had harmful effects, on myocardial I/R injury in monkeys with preexisting atherosclerosis. The mechanism of this negative interaction remains unclear but may relate to Soy's negative effects on hemodynamics.