Introduction: Modulating tissue-resident stem and progenitor cells with a non-invasive, mechanobiological intervention is an optimal approach for tissue regeneration. Stem cell antigen-1 (Sca-1) has been identified as a stem cell marker within many organs but never within the penis. Aim: To localize and isolate penile stem/progenitor cells (PSPCs) and to evaluate cellular differentiation after exposure to induction medium and microenergy acoustic pulse (MAP) therapy. Methods: Six male Sprague-Dawley rats were used to isolate PSPCs. Isolation was followed by stem cell characterization and differentiation assays. The PSPCs were then treated with MAP (0.033 mJ/mm(2), 1 Hz) at various dosages (25, 50, 100, and 200 pulses) and for different durations (1, 2, 4, 6, or 8 hours) in vitro. Main Outcome Measure: The PSPCs (Sca-1-positive cells) were isolated using the magnetic-activated cell sorting system. PSPC cellular differentiation was assessed after induction with induction medium and with MAP in vitro. Wnt/beta-catenin signaling was also assayed. Results: The PSPCs were successfully localized within the penile subtunic and perisinusoidal spaces, and they were successfully isolated using magnetic-activated cell sorting. The stemness of the cells was confirmed by stem cell marker characterization and by multiple differentiation into smooth muscle cells, endothelial cells, adipocytes, and neurons. MAP-induced PSPCs differentiated into smooth muscle cells by activating the Wnt/beta-catenin signaling pathway in a time- and dosage-dependent manner. Clinical Implications: By modulating resident PSPCs, MAP may have utility in the treatment of erectile dysfunction (ED). Strengths & Limitations: This study provides solid evidence in support of microenergy therapies, including both MAP and low-intensity extracorporeal shock wave therapy, for the treatment of ED. Additional studies are needed and should include additional stem cells markers. Furthermore, studies exploring the underling mechanisms for PSPC activation and differentiation are required. Conclusion: PSPCs were successfully identified, localized, and isolated. Additionally, MAP provoked PSPCs to differentiate into smooth muscle cells via the Wnt/beta-catenin signaling pathway. As such, MAP provides a novel method for activating endogenous tissue-resident stem/progenitor cells and might facilitate stem cell regenerative therapy targeting ED. Copyright (C) 2019, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Background: Erectile dysfunction (ED) caused by pelvic neurovascular injury (PNVI) is often refractory to treatment. In many cases, erectogenic therapy is administered in a delayed fashion. Aim: To evaluate penile hemodynamic effects and histologic changes associated with delayed low-intensity extracorporeal shock wave therapy (Li-ESWT) after PNVI ED in a rat model. We visualized images using immunofluorescence and 3-dimensional imaging of solvent-cleared organs (3DISCO), a novel imaging technique. Methods: A total of 32 Sprague-Dawley male rats aged 12 weeks were divided equally into 4 groups: sham surgery as normal controls (NC), PNVI controls (PC), PNVI with very-low-energy Li-ESWT (PVL), and PNVI with low-energy Li-ESWT (PL). Bilateral cavernous nerve crush and internal pudendal bundle ligation were performed in the 3 PNVI groups. Li-ESWT was administered twice a week for 4 weeks in the PL and PVL groups starting at 4 weeks after PNVI. Outcomes: Intracavernous pressure (ICP) studies (normalized to mean arterial pressure [MAP]) were conducted in all subject animals. After testing, tissue was harvested for immunofluorescence staining and 3DISCO analysis. Results: Mean ICP/MAP was lower in PC animals compared with NC animals (0.37 0.03 vs 0.91 0.03, respectively; P =.001). The ICP/MAP ratio was significantly higher in PVL and PL animals (0.66 0.07 and 0.82 0.05, respectively) compared with PC animals (P =.002 and.001, respectively). Detailed microstructures and trajectories of nerves and vessels were identified with immunofluorescence and 3DISCO. The PC group had lower density of nerves, axons, neuronal nitric oxide synthase positive nerves, and Schwann cells in the dorsal penis. Animals in the PL group had significantly higher expression of all of these markers compared with PC animals. Clinical Implications: Li-EWST may have utility in the management of severe ED related to PNVI from severe pelvic injury or radical pelvic surgeries, even when administered in a delayed fashion. Strength & Limitations: This study of a severe ED phenotype involved treatment administered in a delayed fashion, which is more consistent with how therapy likely would be delivered in a real-world clinical context. Moreover, because the treatment commenced at 4 weeks after injury, when nerve and tissue atrophy have already occurred, the results imply that Li-ESWT can be used for regenerative therapy. Additional studies on dose optimization and treatment interval are needed to inform the design of human clinical trials. Conclusion: Li-ESWT ameliorates the negative functional and histologic effects of severe pelvic neurovascular injury in a rat model system. 3DISCO provides high-resolution images of neuroanatomy and neural regeneration.Copyright (C) 2018, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

Aim To investigate the possibility and mechanism of microenergy acoustic pulses (MAP) for activating tissue resident stem/progenitor cells within pelvic and urethral muscle and possible mechanism. Methods The female Zucker Lean and Zucker Fatty rats were randomly divided into four groups: ZL control, ZLMAP, ZF control, and ZFMAP. MAP was applied at 0.033 mJ/mm(2), 3 Hz for 500 pulses, and the urethra and pelvic floor muscles of each rat was then harvested for cell isolation and flow cytometry assay. Freshly isolated cells were analyzed by flow cytometry for Pax-7, Int-7 alpha, H3P, and EdU expression. Meanwhile, pelvic floor muscle-derived stem cells (MDSCs) were harvested through magnetic-activated cell sorting, MAP was then applied to MDSCs to assess the mechanism of stem cell activation. Results Obesity reduced EdU-label-retaining cells and satellite cells in both pelvic floor muscle and urethra, while MAP activated those cells and enhanced cell proliferation, which promoted regeneration of striated muscle cells of the pelvic floor and urethral sphincter. Activation of focal adhesion kinase (FAK)/AMP-activated protein kinase (AMPK) /Wnt/beta-catenin signaling pathways by MAP is the potential mechanism. Conclusions MAP treatment activated tissue resident stem cells within pelvic floor and urethral muscle in situ via activating FAK-AMPK and Wnt/beta-catenin signaling pathway.

Background Stress urinary incontinence (SUI) is a common disorder with high prevalence in women across their life span, but there are no non-surgical curative options for the condition. Stem cell-based therapy, especially endogenous stem cell therapy may be a potential treatment method for SUI. The aims of this study are to identify, isolate, and assay the function of urethral striated muscle derived stem/progenitor cells (uMDSCs) and to assess uMDSC response to microenergy acoustic pulses (MAP). Methods Urethral striated muscle was identified utilizing 3D imaging of solvent organs (3DISCO) and immunofluorescence (IF). uMDSCs were isolated and purified from Zucker Lean (ZL) (ZUC-LEAN) (ZUC-Leprfa 186) rats, with magnetic-activated cell sorting (MACS) and pre-plating methods. The stemness and differentiation potential of the uMDSCs were measured by cell proliferation, EdU, flow cytometry, IF, and Western blot. Results Comparison of the cell proliferation assays between MACS and pre-plating reveals the advantage of MACS over pre-plating. In addition, the study reveals that uMDSCs form myotubes when treated with MAP. Conclusions The uMDSCs within female rat urethral striated muscle could be a therapeutic target of MAP in managing SUI.

Obesity-associated erectile dysfunction (ED) involves pathologic change that may be related to deficit of the penile endogenous stem/progenitor cells. Therefore, an in-depth study of the penile stem/progenitor cells in the pathogenesis of ED is warranted. For this study, eight Zucker Lean (ZUC-Lepr(fa) 186; ZL group) and 16 Zucker Fatty (ZUC-Lepr(fa) 185; ZF) male rats received an intraperitoneal injection of 5-ethynyl-2-deoxyuridine (EdU) to track endogenous stem cells. Twelve weeks later, the ZF rats were randomized to gavage feeding with 1.5mg/kg/day of icariside II (ZF + ICA II group) or the solvent (ZF group). Treatment lasted 4 weeks and was followed by a 1-week washout period. ZF rats had impaired erectile function with related pathologic changes compared with ZL rats. ICA II treatment restored erectile function and prevented smooth muscle atrophy, endothelial dysfunction, and lipid accumulation compared with no treatment. EdU label-retaining cell levels were higher in the ZF + ICA II group compared with the ZF group. Histone 3 phosphorylation at Ser 10, a specific mitotic cell marker, was additionally used to identify dividing cells. ICA II activated more penile stem cells to proliferate in ZF rats compared with ZL rats. These results suggest that ZF rats can be used as a model for obesity-associated ED and that ICA II improves erectile function and pathologic changes through endogenous progenitor cell preservation and proliferation.