Bone Marrow-Derived Cells Implanted into Radiation-Injured Urinary Bladders Reconstruct Functional Bladder Tissues in Rats

Bi-layered adipose mesenchymal cell sheets improve bladder compliance in spinal cord-injured rats

To improve bladder compliance in patients with low-compliance bladders, augmentation cystoplasty with the intestinal tract is performed. However, the use of the intestinal tract often leads to serious surgical complications. Tissue engineering technologies have the potential to improve bladder compliance without using the intestinal tract. In this study, we fabricated bi-layered adipose-derived mesenchymal cell (AMC) sheets and then determined whether the bi-layered AMC sheets could improve bladder compliance in rats with spinal cord injury (SCI). The abdominal adipose tissues of green fluorescence protein (GFP)-transfected Sprague-Dawley (SD) rats were harvested, and the attached and proliferating cells on type Ⅰ collagen were used as AMCs. The AMCs were then cultured on temperature-responsive culture dishes. After reaching over-confluence, the AMCs that maintained cell-cell contacts were detached from the dishes and applied to a gelatin hydrogel sheet. Then, another detached AMC monolayer was accumulated on the AMC monolayer-applied gelatin. Prior to 4 weeks of transplantation, the levels of T8-9 in the spinal cords of recipient SD rats were partially transected. After producing the bi-layered AMC sheets and the rats with SCI, the detrusor muscles of the anterior bladder walls of the rats with SCI were incised, and the bi-layered AMC sheet was patch-transplanted onto the exposed bladder epithelium (n = 8). As a control, the sham operation was performed (n = 7). Four weeks after the transplantation, bladder capacity and bladder compliance in AMC sheet-transplanted SCI-rats were significantly higher than those in sham-operated control SCI-rats. The smooth muscle layers in AMC sheet-transplanted bladders were significantly larger than those in control bladders. In addition, the collagen fibers in the AMC sheet-transplanted bladders were significantly smaller than those in the control bladders. Some GFP-positive transplanted AMCs differentiated into SMA- or desmin-positive cells. Furthermore, GFP-positive cells secreted transforming growth factor-β1 or vascular endothelial growth factor. Therefore, this study showed that bi-layered AMC sheets could improve bladder compliance and bladder tissues in SCI rats.

Revolutionizing Radiotoxicity Management with Mesenchymal Stem Cells and Their Derivatives: A Focus on Radiation-Induced Cystitis

Although radiation therapy plays a crucial role in cancer treatment, and techniques have improved continuously, irradiation induces side effects in healthy tissue. Radiation cystitis is a potential complication following the therapeutic irradiation of pelvic cancers and negatively impacts patients' quality of life (QoL). To date, no effective treatment is available, and this toxicity remains a therapeutic challenge. In recent times, stem cell-based therapy, particularly the use of mesenchymal stem cells (MSC), has gained attention in tissue repair and regeneration due to their easy accessibility and their ability to differentiate into several tissue types, modulate the immune system and secrete substances that help nearby cells grow and heal. In this review, we will summarize the pathophysiological mechanisms of radiation-induced injury to normal tissues, including radiation cystitis (RC). We will then discuss the therapeutic potential and limitations of MSCs and their derivatives, including packaged conditioned media and extracellular vesicles, in the management of radiotoxicity and RC.

Non-Muscular Invasive Bladder Cancer: Re-envisioning Therapeutic Journey from Traditional to Regenerative Interventions

Non-muscular invasive bladder cancer (NMIBC) is one of the most common cancer and major cause of economical and health burden in developed countries. Progression of NMIBC has been characterized as low-grade (Ta) and high grade (carcinoma in situ and T1). The current surgical intervention for NMIBC includes transurethral resection of bladder tumor; however, its recurrence still remains a challenge. The BCG-based immunotherapy is much effective against low-grade NMIBC. BCG increases the influx of T cells at bladder cancer site and inhibits proliferation of bladder cancer cells. The chemotherapy is another traditional approach to address NMIBC by supplementing BCG. Notwithstanding, these current therapeutic measures possess limited efficacy in controlling NMIBC, and do not provide comprehensive long-term relief. Hence, biomaterials and scaffolds seem an effective medium to deliver therapeutic agents for restructuring bladder post-treatment. The regenerative therapies such as stem cells and PRP have also been explored for possible solution to NMIBC. Based on above-mentioned approaches, we have comprehensively analyzed therapeutic journey from traditional to regenerative interventions for the treatment of NMIBC.

Impact of low-dose tadalafil on adverse events after low-dose-rate brachytherapy for prostate cancer: A bi-center randomized open-label trial

OBJECTIVE

To study the efficacy of phosphodiesterase-5 inhibitor tadalafil in attenuating adverse events after low-dose-rate brachytherapy for prostate cancer.

METHODS

This was a randomized open-label trial, conducted at two institutions. Prostate cancer patients undergoing low-dose-rate brachytherapy were randomly assigned to receive tadalafil (study group) or tamsulosin (control group). The primary endpoint was International Prostate Symptom Score for subjective evaluation of lower urinary tract symptoms. Uroflowmetry, postvoid residual urine volume, and Sexual Health Inventory for Men score were the secondary endpoints. Each clinical variable was evaluated during a follow-up period of 1 year after low-dose-rate brachytherapy.

RESULTS

A total of 107 patients were enrolled in this study, with a final total of 96 patients analyzed. The mean total International Prostate Symptom Score changes at 1, 3, 6, 9, and 12 months after low-dose-rate brachytherapy were +7.4, +7.1, +4.7, +1.5, and +0.8, respectively, in the tamsulosin group, and +8.5, +9.2, +6.4, +4.1, and +1.6, respectively, in the tadalafil group. There were no statistically significant differences in International Prostate Symptom Score with the exception of the score at 9-month follow-up. Moreover, there were no statistically significant differences in any of the uroflowmetry or postvoid residual urine volume findings. The Sexual Health Inventory for Men score in the tadalafil group was significantly higher than that in the tamsulosin group at 6, 9, and 12 months after low-dose-rate brachytherapy.

CONCLUSIONS

Tadalafil could be an effective option for the management of lower urinary tract symptoms after low-dose-rate brachytherapy.

Therapeutic effects of Choreito, a traditional Japanese (Kampo) medicine, on detrusor overactivity induced by acetic acid in rats

Choreito (CRT), a traditional Japanese (Kampo) medicine, is widely used for the treatment of overactive bladder (OAB) and other lower urinary tract symptoms in Japan. This study aimed to identify the effects and therapeutic mechanism of CRT on the improvement of detrusor overactivity (DO) using an experimental rat model. Forty-five female Sprague-Dawley rats were equally divided into three groups: intravesical saline instillation with normal food (normal group), intravesical acetic acid (AA) instillation with normal food (AA group), and intravesical AA instillation with CRT (AA with CRT group). To induce a decrease in bladder capacity, instillation of 0.2% AA was used based on prior studies. Cystometric investigation was employed to clarify the effects of AA and CRT. Microcirculation was performed using a laser blood flowmeter, and the localization of hypoxia-inducible factor 1α (HIF1α) was assessed by immunohistochemistry. The bladder capacities of the normal, AA, and AA with CRT groups were 1.2 ± 0.3 mL, 0.4 ± 0.1 mL, and 0.8 ± 0.1 mL, respectively. CRT significantly attenuated AA irritation of the urinary bladder and exerted protective effects on basal pressure, micturition pressure, micturition interval, and micturition volume. Furthermore, CRT could prevent the excess blood flow and edematous change under the urothelium induced by intravesical AA instillation. No obvious changes in immunohistochemical HIF1α staining were observed among the groups. CRT attenuated DO induced by intravesical AA instillation in a rat experimental model. CRT might impart therapeutic effects on OAB via the mitigation of urothelial damage and regulation of excess blood flow.

The Therapeutic Effect of Adipose-Derived Mesenchymal Stem Cells for Radiation-Induced Bladder Injury

This study was designed to investigate the protective effect of adipose derived mesenchymal stem cells (AdMSCs) against radiation-induced bladder injury (RIBI). Female rats were divided into 4 groups: (a) controls, consisting of nontreated rats; (b) radiation-treated rats; (c) radiation-treated rats receiving AdMSCs; and (d) radiation-treated rats receiving AdMSCs conditioned medium. AdMSCs or AdMSCs conditioned medium was injected into the muscular layer of bladder 24 h after radiation. Twelve weeks after radiation, urinary bladder tissue was collected for histological assessment and enzyme-linked immunosorbent assay (ELISA) after metabolic cage investigation. At the 1 w, 4 w, and 8 w time points following cells injection, 3 randomly selected rats in RC group and AdMSCs group were sacrificed to track injected AdMSCs. Metabolic cage investigation revealed that AdMSCs showed protective effect for radiation-induced bladder dysfunction. The histological and ELISA results indicated that the fibrosis and inflammation within the bladder were ameliorated by AdMSCs. AdMSCs conditioned medium showed similar effects in preventing radiation-induced bladder dysfunction. In addition, histological data indicated a time-dependent decrease in the number of AdMSCs in the bladder following injection. AdMSCs prevented radiation induced bladder dysfunction and histological changes. Paracrine effect might be involved in the protective effects of AdMSCs for RIBI.

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.