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

Association of plasma high-density lipoprotein cholesterol level with risk of stress urinary incontinence in women: a retrospective study

BACKGROUND

Studies have found that high density lipoprotein cholesterol (HDL-C) levels are linked to a variety of diseases. However, evidence for the relationship between stress urinary incontinence (SUI) and HDL-C remain limited.

METHODS

590 eligible women were enrolled. Basic characteristic, gynecological examinations and blood sampling were collected. The examination of the possible link between HDL-C and SUI was done using univariate and multivariate logistic regression. Feature importance ranking and Receiver operating characteristic (ROC) curves were performed to further evaluate the association between HDL-C and SUI in women.

RESULTS

A significant association was found between HDL-C and SUI in women, revealing higher HDL-C levels were related to a lower risk of SUI (OR 0.238; 95%CI: 0.091-0.623; P < 0.01) after adjustment for potential key confounders. The AUC for the SUI predicted by the combined HDL-C was 0.845 (95%CI: 0.798-0.891, P < 0.001). The feature importance ranking revealed that vaginal delivery, HDL-C were the top two important factors.

CONCLUSIONS

HDL-C levels were correlated with the development of SUI. In addition to physical and surgical treatments, HDL-C may offer the possibility of potential targeted treatment and prevention of SUI afterwards.

Production of Proliferation- and Differentiation-Competent Porcine Myoblasts for Preclinical Studies in a Porcine Large Animal Model of Muscular Insufficiency

Muscular insufficiency is observed in many conditions after injury, chronic inflammation, and especially in elderly populations. Causative cell therapies for muscle deficiencies are not state of the art. Animal models to study the therapy efficacy are, therefore, needed. We developed an improved protocol to produce myoblasts suitable for pre-clinical muscle therapy studies in a large animal model. Myoblasts were isolated from the striated muscle, expanded by employing five different protocols, and characterized on transcript and protein expression levels to determine procedures that yielded optimized regeneration-competent myoblasts and multi-nucleated myotubes. We report that swine skeletal myoblasts proliferated well under improved conditions without signs of cellular senescence, and expressed significant levels of myogenic markers including Pax7, MyoD1, Myf5, MyoG, Des, Myf6, CD56 (p ≤ 0.05 each). Upon terminal differentiation, myoblasts ceased proliferation and generated multi-nucleated myotubes. Injection of such myoblasts into the urethral sphincter complex of pigs with sphincter muscle insufficiency yielded an enhanced functional regeneration of this muscle (81.54% of initial level) when compared to the spontaneous regeneration in the sham controls without myoblast injection (67.03% of initial level). We conclude that the optimized production of porcine myoblasts yields cells that seem suitable for preclinical studies of cell therapy in a porcine large animal model of muscle insufficiency.

Cell Therapy by Mesenchymal Stromal Cells Versus Myoblasts in a Pig Model of Urinary Incontinence

The leading cause of stress urinary incontinence (SUI) in women is the urethral sphincter muscle deficiency caused by mechanical stress during pregnancy and vaginal delivery. In men, prostate cancer surgery and injury of local nerves and muscles are associated with incontinence. Current treatment often fails to satisfy the patient's needs. Cell therapy may improve the situation. We therefore investigated the regeneration potential of cells in ameliorating sphincter muscle deficiency and UI in a large animal model. Urethral sphincter deficiency was induced surgically in gilts by electrocautery and balloon dilatation. Adipose tissue-derived stromal cells (ADSCs) and myoblasts from Musculus semitendinosus were isolated from male littermates, expanded, characterized in depth for expression of marker genes and in vitro differentiation, and labeled. The cells were injected into the deficient sphincter complex of the incontinent female littermates. Incontinent gilts receiving no cell therapy served as controls. Sphincter deficiency and functional regeneration were recorded by monitoring the urethral wall pressure during follow-up by two independent methods. Cells injected were detected in vivo during follow-up by transurethral fluorimetry, ex vivo by fluorescence imaging, and in cryosections of tissues targeted by immunofluorescence and by polymerase chain reaction of the sex-determining region Y (SRY) gene. Partial spontaneous regeneration of sphincter muscle function was recorded in control gilts, but the sphincter function remained significantly below levels measured before induction of incontinence (67.03% ± 14.00%, n = 6, p < 0.05). Injection of myoblasts yielded an improved sphincter regeneration within 5 weeks of follow-up but did not reach significance compared to control gilts (81.54% ± 25.40%, n = 5). A significant and full recovery of the urethral sphincter function was observed upon injection of ADSCs within 5 weeks of follow-up (100.4% ± 23.13%, n = 6, p < 0.05). Injection of stromal cells provoked slightly stronger infiltration of CD45pos leukocytes compared to myoblasts injections and controls. The data of this exploratory study indicate that ADSCs inherit a significant potential to regenerate the function of the urethral sphincter muscle.

Serum albumin levels and stress urinary incontinence in females: A retrospective study based on NHANES 2007-2016

Background

Serum albumin (sAlb) is an essential indicator of human physiological function. However, the correlation between the concentration of sAlb and stress urinary incontinence (SUI) remains poorly understood.

Methods

The sAlb was measured using the bichromatic digital endpoint method. The SUI was assessed according to information from the National Health and Nutrition Examination Survey (NHANES) questionnaire. Univariate and multivariate logistic regression analyses of the potential correlation between sAlb and stress incontinence were performed. Subgroup analysis was also conducted according to body mass index (BMI).

Results

After adjusting for potential key confounders, sAlb was found to have a significant association with SUI in adult females, and higher sAlb levels were associated with a lower risk of SUI (OR = 0.849; 95 % CI: 0.724-0.994; P = 0.042). Furthermore, subgroup analysis indicated that sAlb was associated with reduced SUI risk only in the subgroup with a body mass index (BMI) ≥ 30 (OR = 0.762; 95 % CI: 0.595-0.975; P = 0.030).

Conclusion

Female SUI was correlated with sAlb concentration, and a lower risk of SUI was seen in those with greater sAlb levels. These findings provide new insights into SUI prevention.

Stress Urinary Incontinence: An Unsolved Clinical Challenge

Stress urinary incontinence is still a frequent problem for women and men, which leads to pronounced impairment of the quality of life and withdrawal from the social environment. Modern diagnostics and therapy improved the situation for individuals affected. But there are still limits, including the correct diagnosis of incontinence and its pathophysiology, as well as the therapeutic algorithms. In most cases, patients are treated with a first-line regimen of drugs, possibly in combination with specific exercises and electrophysiological stimulation. When conservative options are exhausted, minimally invasive surgical therapies are indicated. However, standard surgeries, especially the application of implants, do not pursue any causal therapy. Non-absorbable meshes and ligaments have fallen into disrepute due to complications. In numerous countries, classic techniques such as colposuspension have been revived to avoid implants. Except for tapes in the treatment of stress urinary incontinence in women, the literature on randomized controlled studies is insufficient. This review provides an update on pharmacological and surgical treatment options for stress urinary incontinence; it highlights limitations and formulates wishes for the future from a clinical perspective.

Research trends of acupuncture therapy on stress urinary incontinence from 1992 to 2022: A bibliometric analysis

Background

Stress urinary incontinence (SUI), the most prevalent type of urinary incontinence disorder, has aroused increasing attention among societies since it has caused much inconvenience in daily life. In addition to conventional conservative treatments like medication and pelvic floor muscle training, acupuncture is now frequently advised. However, a bibliometric analysis of the trend of SUI therapies is still lacking.

Objectives

This article was carried out using CiteSpace (6.3.1) software to research the use of acupuncture therapy on SUI worldwide over the past 30 years (since the database's inception).

Methods

All related articles included were retrieved from the Web of Science Core Collection. CiteSpace (6.3.1) software was used to analyze the number of publications, countries and institutions, authors and cited authors, and burst keywords to assess the hotspots and trends over the previous three decades. And Microsoft Office Excel 2019 was also used for sorting data and generating tables.

Results

The articles were retrieved on August 31, 2022. A total of 108 records with publication dates ranging from 1992 to 2022 were discovered. The annual number of publications generally increased. In the aspect of publication regions, the USA ranked first in centrality, but China had the largest number of publications. The China Academic of Chinese Medical Sciences, Beijing University of Chinese Medicine, and Shanghai University of Traditional Chinese Medicine were the top 3 institutions, according to the institution map. Liu Z (Liu ZS) was the most productive author, and Chen Y ranked first in the centrality. The article published by Liu Z (Liu ZS) in 2017 was the most cited reference. "Bladder neck suspension", "electrical stimulation" and "acupuncture" were popular therapies mentioned among the top ten hot topics. The keywords "therapy", "postprostatectomy incontinence", "muscle", "cell therapy", and "symptom" ranked in the top five on citation burst. The four frontier topics were "efficacy", "symptom", "cell therapy", and "medical technology".

Conclusion

This study illustrated that the application of acupuncture on SUI had an increasing acceptance worldwide. Recent research has concentrated mainly on acupuncture and electroacupuncture, however, there is still not enough literature on these topics. The valuable information was provided for acupuncture researchers to identify prospects including potential collaborators, cooperation institutions, hot themes, and research frontiers.

Effects of Age and Multiple Vaginal Births on Lower Urinary Tract Structure and Function in Nonhuman Primates

Purpose: The relative roles of urinary sphincter damage, aging, and childbirth in stress urinary incontinence (SUI), have not been established. This study was performed to elucidate the roles of these factors.Methods: The study included: (1) 8 female cynomolgus monkeys (17–19 years of age and 7–8 vaginal births each); (2) six 5-yearold nulliparous monkeys with surgically created chronic urinary sphincter dysfunction; and (3) six 5-year-old, nulliparous, nosurgery controls. Sedated abdominal leak point pressure (ALPP) and maximum urethral sphincter pressures (MUP) were measured. Sphincters, bladders, and pelvic support muscles were quantified for collagen content. Additionally, bladders were analyzed for collagen fiber thickness, length, and angle using CT-FIRE analysis of Picrosirius red-stained tissues.Results: Resting MUP values were similar in the controls and older multiparous monkeys (P>0.05). However, aging and multiple births reduced pudendal nerve-stimulated increases in MUP (P<0.05 vs. controls). ALPP values were lower in the older multiparous versus younger groups of monkeys (P<0.05). Sphincter collagen content was greater, and muscle content less, in the injury model (P<0.05 vs. controls). However, these measures were not affected by age and childbirth (P>0.05 vs. young groups). Bladder collagen content was greater, and muscle content less, in the old multiparous monkeys (P<0.05 vs. younger groups). Additionally, collagen fibers were thicker and more angular in the bladders of the older multiparous monkeys than in the other nonhuman primate groups (P<0.05). Pelvic support muscles had higher collagen and lower muscle content in the older multiparous monkeys than in the younger groups of monkeys (P<0.05).Conclusions: SUI, associated with aging and multiple childbirths, appeared to be more strongly associated with bladder dysfunction, reduced pelvic muscle support, and the compensatory response to neural stimulation than with selective urinary sphincter dysfunction.

Differentiation of patient-specific void urine-derived human induced pluripotent stem cells to fibroblasts and skeletal muscle myocytes

Cell-based therapy is a major focus for treatment of stress urinary incontinence (SUI). However, derivation of primary cells requires tissue biopsies, which often have adverse effects on patients. A recent study used human induced pluripotent stem cells (iPSC)-derived smooth muscle myocytes for urethral sphincter regeneration in rats. Here, we establish a workflow using iPSC-derived fibroblasts and skeletal myocytes for urethral tissue regeneration: (1) Cells from voided urine of women were reprogrammed into iPSC. (2) The iPSC line U1 and hESC line H9 (control) were differentiated into fibroblasts expressing FSP1, TE7, vinculin, vimentin, αSMA, fibronectin and paxillin. (3) Myogenic differentiation of U1 and H9 was induced by small molecule CHIR99021 and confirmed by protein expression of myogenic factors PAX7, MYOD, MYOG, and MF20. Striated muscle cells enriched by FACS expressed NCAM1, TITIN, DESMIN, TNNT3. (4) Human iPSC-derived fibroblasts and myocytes were engrafted into the periurethral region of RNU rats. Injected cells were labelled with ferric nanoparticles and traced by Prussian Blue stain, human-specific nuclear protein KU80, and human anti-mitochondria antibody. This workflow allows the scalable derivation, culture, and in vivo tracing of patient-specific fibroblasts and myocytes, which can be assessed in rat SUI models to regenerate urethral damages and restore continence.

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.

Human primary muscle stem cells regenerate injured urethral sphincter in athymic rats

Background

The aim of the study was to demonstrate the efficacy of human muscle stem cells (MuSCs) isolated using innovative technology in restoring internal urinary sphincter function in a preclinical animal model.

Methods

Colonies of pure human MuSCs were obtained from muscle biopsy specimens. Athymic rats were subjected to internal urethral sphincter damage by electrocauterization. Five days after injury, 2 × 10⁵ muscle stem cells or medium as control were injected into the area of sphincter damage (n = 5 in each group). Peak bladder pressure and rise in pressure were chosen as outcome measures. To repeatedly obtain the necessary pressure values, telemetry sensors had been implanted into the rat bladders 10 days prior to injury.

Results

There was a highly significant improvement in the ability to build up peak pressure as well as a pressure rise in animals that had received muscle stem cells as compared to control (p = 0.007) 3 weeks after the cells had been injected. Only minimal histologic evidence of scarring was observed in treated rats.

Conclusion

Primary human muscle stem cells obtained using innovative technology functionally restore internal urethral sphincter function after injury. Translation into use in clinical settings is foreseeable.

Replacing Needle Injection by a Novel Waterjet Technology Grants Improved Muscle Cell Delivery in Target Tissues

Current regimen to treat patients suffering from stress urinary incontinence often seems not to yield satisfactory improvement or may come with severe side effects. To overcome these hurdles, preclinical studies and clinical feasibility studies explored the potential of cell therapies successfully and raised high hopes for better outcome. However, other studies were rather disappointing. We therefore developed a novel cell injection technology to deliver viable cells in the urethral sphincter complex by waterjet instead of using injection needles. We hypothesized that the risk of tissue injury and loss of cells could be reduced by a needle-free injection technology. Muscle-derived cells were obtained from young male piglets and characterized. Upon expansion and fluorescent labeling, cells were injected into cadaveric tissue samples by either waterjet or injection needle. In other experiments, labeled cells were injected by waterjet in the urethra of living pigs and incubated for up to 7 days of follow-up. The analyses documented that the cells injected by waterjet in vitro were viable and proliferated well. Upon injection in live animals, cells appeared undamaged, showed defined cellular somata with distinct nuclei, and contained intact chromosomal DNA. Most importantly, by in vivo waterjet injections, a significantly wider cell distribution was observed when compared with needle injections (P < .05, n ≥ 12 samples). The success rates of waterjet cell application in living animals were significantly higher (≥95%, n = 24) when compared with needle injections, and the injection depth of cells in the urethra could be adapted to the need by adjusting waterjet pressures. We conclude that the novel waterjet technology injects viable muscle cells in tissues at distinct and predetermined depth depending on the injection pressure employed. After waterjet injection, loss of cells by full penetration or injury of the tissue targeted was reduced significantly in comparison with our previous studies employing needle injections.

Stem Cells in Clinical Trials for Pelvic Floor Disorders: a Systematic Literature Review

Pelvic floor disorders (PFDs) include a series of conditions that can be poorly tolerated, negatively affecting the quality of life. Current treatment options show unsatisfactory results and new ones are therefore needed. Stem cell (SC) therapy might be an alternative treatment strategy. This systematic review aims to define the state of art of SC therapy for PFDs in clinical trials, by systematically reviewing the available evidence. A systematic search strategy was conducted up to November 7, 2020, in PubMed, Scopus, Cochrane Library, and ISI Web of Science. Preclinical studies on animal models were not considered. Studies were included when the patients were affected by any PFDs and cells were isolated, cultured, and characterized as SC. The study protocol was registered in PROSPERO (CRD42020216551). A total of 11 prospective clinical studies were included in the final assessment, specifically 7 single-arm studies dealing with SC therapy for stress urinary incontinence and 4 with anal incontinence. Among the latter, there were two prospective, single-arm studies and two randomized controlled trials. No papers concerning the use of SC for prolapse repair were retrieved. Due to the great heterogeneity, data pooling was not possible. Stem cell injection resulted in a safe procedure, with few mild adverse side effects, mostly related to harvesting sites. However, a clear beneficial impact of SC treatment for the treatment of pelvic floor disorders could not be demonstrated. Further larger targeted studies with control arms are needed before any conclusions can be made.