The Current Status of Stem-Cell Therapy in Erectile Dysfunction: A Review

Repeated Injections of Mesenchymal Stem Cell-Derived Exosomes Ameliorate Erectile Dysfunction in a Cavernous Nerve Injury Rat Model

PURPOSE

To evaluate the therapeutic effect of repeated injections of mesenchymal stem cell (MSC)-derived exosomes on the erectile dysfunction (ED) of bilateral cavernous nerve injury (BCNI) rat model and to identify potential target genes of these injections.

MATERIALS AND METHODS

MSC-derived exosomes were isolated using an aqueous two-phase system. Rats were randomly assigned into four groups: Normal, BCNI, exosome once, and exosome-repeat groups. After four weeks, we measured the intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio to evaluate erectile function and examined cavernous nerve tissues for histological and molecular analyses. RNA sequencing in penile tissues was used to determine differentially expressed genes and was verified by quantitative polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were used for in vitro studies to analyze biological roles.

RESULTS

The ICP/MAP ratios in the exosome-once and exosome-repeat groups were significantly increased compared to those in the BCNI group. Interestingly, the ICP/MAP ratio showed a greater increase in the exosome-repeat group, which also showed significantly increased smooth muscle/collagen ratio, α-smooth muscle actin and neuronal nitric oxide synthase expression, and cyclic guanosine monophosphate level compared to the BCNI and exosome-once groups. Three genes were significantly differentially expressed in the exosome group, among which Ras homolog family member B promoted cell proliferation and angiogenesis of HUVECs.

CONCLUSIONS

Repeated injections of MSC-derived exosomes can be effective in the treatment of rat models with ED induced by cavernous nerve injury.

Vascular endothelium is the basic way for stem cells to treat erectile dysfunction: a bibliometric study

Vascular endothelial is considered to be a key factor in the pathogenesis of erectile dysfunction (ED). The purpose is to reveal the research trend of the field of ED and vascular endothelium. In addition, the goal is to discover the role and mechanism of vascular endothelium in ED. Bibliometrics and visualization methods based on CiteSpace were selected. We conducted the co-authorship analysis of countries, institutions and authors, co-occurrence analysis of keywords, and co-citation analysis of literature and authors through CiteSpace 6.1.R3. 1431 articles from Web of Science Core Collection (WOSCC) were included in the analysis from 1991 to 2022. We found some influential and cutting-edge nodes in each map, including countries, institutions, authors, articles, etc. Stem cell, therapy, oxidative stress, cavernous nerve injury, radical prostatectomy, fibrosis, erectile function, mesenchymal stem cell, and apoptosis may be hot keywords. In conclusion, the efficacy and mechanisms of stem cells and their derivatives in the treatment of diabetes (DM) ED and cavernous nerve injury (CNI) ED are the future research trends. Stem cells therapy for ED is a hot spot in this field, which side notes that stem cells may work mainly through improving endothelial function. Vascular endothelial cells and VEGF may repair nerve and cavernous smooth muscle directly or indirectly, and finally polish up erectile function.

Improvement of erectile dysfunction using endothelial progenitor cells from fetal cerebral vasculature in the cavernous nerve injury of rats

BACKGROUND

Because of limited differentiation to endothelium from mesenchymal stem cells, it has been strongly recommended to use endothelial progenitor cells for the regeneration of the damaged endothelium of corpora cavernosa. This study was performed to investigate the immortalized human cerebral endothelial cells and their capability for repairing erectile dysfunction in a rat model of cavernous nerve injury. Circulating endothelial progenitor cells were isolated from human fetal brain vasculature at the periventricular region of telencephalic tissues. Over 95% of CD 31-positive cells were sorted and cultured for 10 days. Human cerebral endothelial progenitor cells were injected into the cavernosa of rats with cavernous nerve injury. Erectile response was then assessed. In in vivo assays, rats were divided into three groups: group 1, sham operation: group 2, bilateral cavernous nerve injury: and group 3, treatment with human cerebral endothelial cells after cavernous nerve injury.

RESULTS

Established immortalized circulating endothelial progenitor cells showed expression of human telomerase reverse transcriptase transcript by RT-PCR. They also showed the expression of vascular endothelial growth factor, von Willebrand factor, vascular endothelial growth factor receptor, and CD31, cell type-specific markers for endothelial cells by RT-PCR. In in vitro angiogenesis assays, they demonstrated tube formation that suggested morphological properties of endothelial progenitor cells. In in vivo assays, impaired erectile function of rat with cavernous nerve injury recovered at 2, 4, and 12 weeks after transplantation of human cerebral endothelial cells into the cavernosa.

CONCLUSIONS

Telomerase reverse transcriptase-circulating endothelial progenitor cells from fetal brain vasculature could repair erectile dysfunction of rats with cavernous nerve injury.

Progress and prospect of stem cell therapy for diabetic erectile dysfunction

Diabetic erectile dysfunction (DED) is a common complication of diabetes mellitus, significantly impairing the quality of life of patients. The conventional clinical treatment still has limitations. Stem cells (SCs), as a type of cells with multidirectional or directional differentiation capability and sustainable self-renewal potential, are widely used in regenerative medicine and tissue engineering. With the continuous update of regenerative medicine theory and the success of animal experiments, SCs as a treatment for male erectile dysfunction, especially DED, have attracted widespread attention because of curable possibility. This review focus on the current progress in the clinical application of SC treatment for DED. Moreover, we summarize the development prospects of SCs in the field of DMED therapy.

Stem cell therapy and diabetic erectile dysfunction: A critical review

Erectile dysfunction (ED) has been identified as one of the most frequent chronic complications of diabetes mellitus (DM). The prevalence of ED is estimated to be about 67.4% in all DM cases worldwide. The pathophysiological process leading to ED involves endothelial, neurological, hormonal, and psychological factors. In DM, endothelial and neurological factors play a crucial role. Damages in the blood vessels and erectile tissue due to insulin resistance are the hallmark of ED in DM. The current treatments for ED include phosphodiesterase-5 inhibitors and penile prosthesis surgery. However, these treatments are limited in terms of just relieving the symptoms, but not resolving the cause of the problem. The use of stem cells for treating ED is currently being studied mostly in experimental animals. The stem cells used are derived from adipose tissue, bone, or human urine. Most of the studies observed an improvement in erectile quality in the experimental animals as well as an improvement in erectile tissue. However, research on stem cell therapy for ED in humans remains to be limited. Nevertheless, significant findings from studies using animal models indicate a potential use of stem cells in the treatment of ED.

A novel flavonoid derivative of icariside II improves erectile dysfunction in a rat model of cavernous nerve injury

BACKGROUND

Icariside II (ICA II), an active flavonoid monomer, has been proven to restore post-prostatectomy erectile dysfunction in rats; however, the high cost of extraction from natural plants limits the application of ICA II.

OBJECTIVE

To investigate the therapeutic effect and possible mechanism of action of YS-10, a new flavonoid compound, which was designed and synthesized based on the structure of ICA II in a rat model in of cavernous nerve injury.

MATERIALS/METHODS

Eight of 32 adult male Sprague-Dawley rats were selected as the normal control (NC) group and received vehicle treatment. The remaining rats were subjected to bilateral cavernous nerve injury (BCNI) and randomized into three groups: BCNI group, BCNI + ICA II group (2.5 mg/kg/day), and BCNI + YS-10 group (2.5 mg/kg/day). The total procedure lasted for 21 days, followed by a washout period of 3 days. All animals were evaluated for erectile function, and tissues were harvested for histopathological analyses.

RESULTS

It was observed that in YS-10 group, the ratio of intracavernous pressure (ICP) to mean arterial pressure (MAP) and the area under the ICP/MAP curve were effectively enhanced. The maximum ICP/MAP increased by 30% in the YS-10 group (0.86 ± 0.085) compared with the BCNI group (0.66 ± 0.058), which is close to 82% of the NC group (1.05 ± 0.033). Histopathological changes demonstrated significant reduction of smooth muscle atrophy, collagen deposition, and endothelial and neural dysfunction after YS-10 treatment, which have no statistical differences compared with ICA II group. Additionally, high-protein expression levels of β-Catenin and cyclin D1 were observed in the treatment groups.

CONCLUSION

YS-10, a novel synthesized flavonoid compound, could effectively improve erectile dysfunction in rats after BCNI by alleviating pathological impairments; this effect may associate with the upregulation of β-Catenin and cyclin D1 in Wnt signaling pathway.

A systematic review of intracavernosal injection of mesenchymal stem cells for diabetic erectile dysfunction

BACKGROUND As current erectile dysfunction (ED) treatments are limited, other treatment such as stem cells should be explored. Hence, this study aimed to review the sources, method of administration, and therapeutic effect of mesenchymal stem cells (MSCs) for diabetic ED treatment. METHODS All relevant articles regarding the use of MSCs for diabetic ED were searched in PubMed and Google Scholar databases from December 15, 2019 to January 1, 2020 published in the past 10 years. The keywords were “mesenchymal stem cells” and “diabetic ED”. The selection and critical appraisal of the studies were discussed. Diabetic ED was evaluated for functional and structural outcome. Functional outcome in animal studies was assessed by intracavernosal pressure/mean arterial pressure (ICP/MAP) ratio, meanwhile the structural outcome was done microscopically. In human study, the assessments were done using international index of erectile function score (IIEF-5) to erection hardness score and penile Doppler ultrasonography. RESULTS There were 10 animal studies and 3 human studies. The studies used MSCs from adipose (n = 6), bone marrow (n = 4), placenta (n = 1), umbilical cord (n = 1), and muscle tissue (n = 1). The MSCs were administrated through intracavernosal injection in all studies. In all animal studies, functional outcome was improved, shown in higher ICP/MAP ratio. Microscopically, there were an increase of cavernosal endothelial cells, vascular endothelial growth factor, nitric oxide synthase, and smooth muscle cells. In human studies, IIEF-5 and erection hardness score were improved. Peak systolic velocity was also higher. CONCLUSIONS MSCs may be a promising therapy for diabetic ED; however, long-term safety concerns still need further investigations.

Role of regenerative therapies on erectile dysfunction after radical prostatectomy

The present study provides a review of stem cell therapy as a treatment of erectile dysfunction from peer-reviewed human and animal trials. A literature search was conducted in PubMed-Medline, Scopus, Embase, and Cochrane databases. Tweenty-three animal studies and seven human studies in the period from 1st of January 2000 to 1st of Mai 2020 were included. The seven included human studies are primary phase one trials, and most of them treat erectile dysfunction following radical prostatectomy by injection of stem cells into the corpus cavernosum. The primary outcome measure in all human trials is safety and secondary can stem cells play a role in the recovery of erectile function. All studies conclude that it is safe to use stem cells and the majority of the studies demonstrate an improvement in erectile function. The results from both animal and human trials are promising for stem cells as a restorative treatment, but data from large randomized human phase two trials is missing before it can be concluded, that stem cells is an effective treatment for erectile dysfunction in humans.

Anatomy, Pathophysiology, Molecular Mechanisms, and Clinical Management of Erectile Dysfunction in Patients Affected by Coronary Artery Disease: A Review

Erectile dysfunction (ED) has been defined as the inability to attain or maintain penile erection sufficient for successful sexual intercourse. ED carries a notable influence on life quality, with significant implications for family and social relationships. Because atherosclerosis of penile arteries represents one of the most frequent ED causes, patients presenting with it should always be investigated for potential coexistent coronary or peripheral disease. Up to 75% of ED patients have a stenosis of the iliac-pudendal-penile arteries, supplying the male genital organ’s perfusion. Recently, pathophysiology and molecular basis of male erection have been elucidated, giving the ground to pharmacological and mechanical revascularization treatment of this condition. This review will focus on the normal anatomy and physiology of erection, the pathophysiology of ED, the relation between ED and cardiovascular diseases, and, lastly, on the molecular basis of erectile dysfunction.

Erectile Dysfunction A Prospective Randomized Placebo-Controlled Study Evaluating the Effect of Low-Intensity Extracorporeal Shockwave Therapy (LI-ESWT) in Men With Erectile Dysfunction Following Radical Prostatectomy

Introduction

Previous studies have indicated that low-intensity extracorporeal shockwave therapy (Li-ESWT) may improve male erectile dysfunction (ED) of vascular aetiology.

Aim

To investigate penile rehabilitation of Li-ESWT in a randomized, placebo-controlled trial in men with ED following robotic nerve-sparing radical prostatectomy (RARP).

Methods

Included were men with ED following nerve-sparing RP with a score <22 in the 5-item International Index of Erectile Function (IIEF-5) questionnaire. Participants were divided into an active A (n = 20) and a placebo/sham B group (n = 18). They were randomized consecutively upon study entry. Each study arm had one treatment a week for 5 weeks.

Main outcome measures

Sexual outcomes were assessed by international validated questionnaires, Erection Hardness Score (EHS) and IIEF-5 at baseline and at 4 and 12 weeks after treatment.

Results

A total of 38 (n = 38) participants were enrolled; there were no dropouts. A significant increase was observed in IIEF-5 and EHS in group A at both 4 and 12 weeks. At 12 weeks, the mean IIEF-5 score had increased by 3.45 points (P = .026), while the mean EHS score had increased by 0.5 points (P= .019).

Conclusion

This randomized study indicates that Li-ESWT for ED in men undergone RP might be effective and safe. However, further and more robust research is needed before Li-ESWT can be characterized as a reliable treatment modality. Ladegaard PBJ, Mortensen J, Skov-Jeppesen SM, et al. Erectile Dysfunction A Prospective Randomized Placebo-Controlled Study Evaluating the Effect of Low-Intensity Extracorporeal Shockwave Therapy (LI-ESWT) in Men With Erectile Dysfunction Following Radical Prostatectomy. Sex Med 2021;9:100338.

New Frontiers or the Treatment of Interstitial Cystitis/Bladder Pain Syndrome - Focused on Stem Cells, Platelet-Rich Plasma, and Low-Energy Shock Wave

Interstitial cystitis/bladder pain syndrome (IC/BPS), which is characterized by bladder pain and irritative voiding symptoms, is a frustrating disease without effective treatment. The cause is still largely not understood, although urothelium ischemia/hypoxia, apoptosis, denudation, and infiltration of inflammatory cells are common histopathological findings. The current uncertainty regarding the etiology and pathology of IC/BPS has a negative impact on its timely and successful treatment; therefore, the development of new treatment modalities is urgently needed. Herein, we present advances in our knowledge on this topic and review the potential application of regenerative medicine for the treatment of IC/BPS. This article provides information on the basic characteristics and clinical evidence of stem cells, platelet-rich plasma (PRP), and low-energy shock waves (LESWs) based on a literature review with a search strategy for articles related to IC/BPS, stem cells, PRP, and LESW published in MEDLINE and PubMed. Stem cells, PRP, and LESW, which modulate inflammatory processes and promote tissue repair, have been proven to improve bladder regeneration, relieve bladder pain, inhibit bladder inflammation, and increase bladder capacity in some preclinical studies. However, clinical studies are still in their infancy. Based on the mechanisms of action of stem cells, PRP, and LESW documented in many preclinical studies, the potential applications of regenerative medicine for the treatment of IC/BPS is an emerging frontier of interest. However, solid evidence from clinical studies remains to be obtained.

Myh11+ microvascular mural cells and derived mesenchymal stem cells promote retinal fibrosis

Retinal diseases are frequently characterized by the accumulation of excessive scar tissue found throughout the neural retina. However, the pathophysiology of retinal fibrosis remains poorly understood, and the cell types that contribute to the fibrotic response are incompletely defined. Here, we show that myofibroblast differentiation of mural cells contributes directly to retinal fibrosis. Using lineage tracing technology, we demonstrate that after chemical ocular injury, Myh11+ mural cells detach from the retinal microvasculature and differentiate into myofibroblasts to form an epiretinal membrane. Inhibition of TGFβR attenuates Myh11+ retinal mural cell myofibroblast differentiation, and diminishes the subsequent formation of scar tissue on the surface of the retina. We demonstrate retinal fibrosis within a murine model of oxygen-induced retinopathy resulting from the intravitreal injection of adipose Myh11-derived mesenchymal stem cells, with ensuing myofibroblast differentiation. In this model, inhibiting TGFβR signaling does not significantly alter myofibroblast differentiation and collagen secretion within the retina. This work shows the complexity of retinal fibrosis, where scar formation is regulated both by TGFβR and non-TGFβR dependent processes involving mural cells and derived mesenchymal stem cells. It also offers a cautionary note on the potential deleterious, pro-fibrotic effects of exogenous MSCs once intravitreally injected into clinical patients.

Restoration of Cavernous Veno-Occlusive Function through Chronic Administration of a Jun-Amino Terminal Kinase Inhibitor and a LIM-Kinase 2 Inhibitor by Suppressing Cavernous Apoptosis and Fibrosis in a Rat Model of Cavernous Nerve Injury: A Comparison with a Phosphodiesterase Type 5 Inhibitor

Purpose

To determine if chronic administration of Jun-amino terminal kinase (JNK)-inhibitors and LIM-kinase 2 (LIMK2)-inhibitors from the immediate post-injury period in a rat model of cavernous-nerve-crush-injury could normalize cavernous-veno-occlusive-function, and to compare it with phosphodiesterase type 5 (PDE5)-inhibitors.

Materials and Methods

A total of 75 12-week-old male Sprague–Dawley-rats were randomized into five groups: sham-surgery (S), cavernous-nerve-crush-injury (I), cavernous-nerve-crush-injury treated with 10.0 mg/kg LIMK2-inhibitor (L) or 10.0 mg/kg JNK-inhibitor and 10.0 mg/kg LIMK2-inhibitor (J+L) or 20.0 mg/kg udenafil (P) for five-weeks. Five-weeks after surgery, dynamic-infusion-cavernosometry, histological-studies, caspase-3-activity-assay, and Western-blot were investigated.

Results

Group-I had lower papaverine-response, higher maintenance-rate and higher drop-rate, compared to Group-S. Group-L, Group-J+L and Group-P showed improvement in the three dynamic-infusion-cavernosometry parameters. The papaverine-response and drop-rate in Group-J+L and Group-P recovered to sham-control level, but those in Group-L did not. Regarding apoptosis, Group-I had decreased content of α-smooth-muscle-actin, increased caspase-3 activity and increased cJun-phosphorylation. The cJun-phosphorylation improved only in Group-J+L. The α-smooth-muscle-actin content and caspase-3-activity in Group-J+L and Group-P improved, but those in Group-L were not. Regarding fibrosis, Group-I had decreased smooth muscle (SM)/collagen-ratio, increased protein-expression of fibronectin, and increased Cofilin-phosphorylation. Cofilin-phosphorylation was normalized in Group-L and Group-J+L, but not in Group-P. SM/collagen-ratio and protein-expression of fibronectin in Group-L, Group-J+L and Group-P improved.

Conclusions

Our data indicate that chronic inhibition of JNK and LIMK2 can restore cavernous-veno-occlusive-function by suppressing cavernous-apoptosis and cavernous-fibrosis, comparable to the results by PDE5-inhibitors. Chronic inhibition of JNK and LIMK2 might be a potential mechanism-specific targeted therapy for cavernous-veno-occlusive-dysfunction induced by cavernous nerve-injury.

The effects of single versus combined therapy using LIM-kinase 2 inhibitor and type 5 phosphodiesterase inhibitor on erectile function in a rat model of cavernous nerve injury-induced erectile dysfunction

We aimed to determine whether combination of LIM-kinase 2 inhibitor (LIMK2i) and phosphodiesterase type-5 inhibitor (PDE5i) could restore erectile function through suppressing cavernous fibrosis and improving cavernous apoptosis in a rat model of cavernous nerve crush injury (CNCI). Seventy 12-week-old Sprague-Dawley rats were equally distributed into five groups as follows: (1) sham surgery (Group S), (2) CNCI (Group I), (3) CNCI treated with daily intraperitoneal administration of 10.0 mg kg^-1 LIMK2i (Group I + L), (4) daily oral administration of 20.0 mg kg^-1 udenafil, PDE5i (Group I + U), and (5) combined administration of 10.0 mg kg^-1 LIMK2i and 20.0 mg kg^-1 udenafil (Group I + L + U). Rats in Groups I + L, I + U, and I + L + U were treated with respective regimens for 2 weeks after CNCI. At 2 weeks after surgery, erectile response was assessed using electrostimulation. Penile tissues were processed for histological studies and western blot. Group I showed lower intracavernous pressure (ICP)/mean arterial pressure (MAP), lower area under the curve (AUC)/MAP, decreased immunohistochemical staining for alpha-smooth muscle (SM) actin, higher apoptotic index, lower SM/collagen ratio, increased phospho-LIMK2-positive fibroblasts, decreased protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) phosphorylation, increased LIMK2/cofilin phosphorylation, and increased protein expression of fibronectin, compared to Group S. In all three treatment groups, erectile responses, protein expression of fibronectin, and SM/collagen ratio were improved. Group I + L + U showed greater improvement in erectile response than Group I + L. SM content and apoptotic index in Groups I + U and I + L + U were improved compared to those in Group I. However, Group I + L did not show a significant improvement in SM content or apoptotic index. The number of phospho-LIMK2-positive fibroblasts was normalized in Groups I + L and I + L + U, but not in Group I + U. Akt/eNOS phosphorylation was improved in Groups I + U and I + L + U, but not in Group I + L. LIMK2/cofilin phosphorylation was improved in Groups I + L and I + L + U, but not in Group I + U. Our data indicate that combined treatment of LIMK2i and PDE5i immediate after CN injury could improve erectile function by improving cavernous apoptosis or eNOS phosphorylation and suppressing cavernous fibrosis. Rectification of Akt/eNOS and LIMK2/cofilin pathways appears to be involved in their improvement.

Phoenix: A Portable, Battery-Powered, and Environmentally Controlled Platform for Long-Distance Transportation of Live-Cell Cultures

Despite the advent of advanced therapy medicinal products (ATMPs) in regenerative medicine, gene therapy, cell therapies, tissue engineering, and immunotherapy, the availability of treatment is limited to patients close to state-of-the-art facilities. The SCORPIO-V Division of HNu Photonics has developed the Phoenix-Live Cell Transport^TM, a battery-operated mobile incubator designed to facilitate long-distance transportation of living cell cultures from GMP facilities to remote areas for increased patient accessibility to ATMPs. This work demonstrates that Phoenix^TM (patent pending) is a superior mechanism for transporting living cells compared to the standard method of shipping frozen cells on dry ice (-80°C) or in liquid nitrogen (-150°C), which are destructive to the biology as well as a time consuming process. Thus, Phoenix will address a significant market need within the burgeoning ATMP industry. SH-SY5Y neuroblastoma cells were cultured in a stationary Phoenix for up to 5 days to assess cell viability and proliferation. The results show there is no significant difference in cell proliferation (∼5X growth on day 5) or viability (>90% viability on all days) when cultured in Phoenix^TM and compared to a standard 5% CO₂ incubator. Similarly, SH-SY5Y cells were evaluated following ground (1-3 days) and air (30 min) shipments to understand the impact of transit vibrations on the cell cultures. The results indicate that there is no significant difference in SH-SY5Y cell proliferation (∼2X growth on day 3) or viability (>90% viability for all samples) when the cells are subjected to the vibrations of ground and air transportation when compared to control samples in a standard, stationary 5% CO₂ incubator. Furthermore, the temperature, pressure, humidity, and accelerometer sensors log data during culture shipment to ensure that the sensitive ATMPs are handled with the appropriate care during transportation. The Phoenix^TM technology innovation will significantly increase the accessibility, reproducibility, and quality-controlled transport of living ATMPs to benefit the widespread commercialization of ATMPs globally. These results demonstrate that Phoenix^TM can transport sensitive cell lines with the same care as traditional culture techniques in a stationary CO₂ incubator with higher yield, less time and labor, and greater quality control than frozen samples.

The Combined Use of Stem Cells and Platelet Lysate Plasma for the Treatment of Erectile Dysfunction: A Pilot Study-6 Months Results

Background: The current treatment of Erectile Dysfunction (ED) is mainly based on the use of drugs that provide erections shortly after use but they do not really treat the problem. Stem cell therapy is a novel treatment with regenerative properties that can possibly treat erectile dysfunction. Methods: Five patients with erectile disease were treated with Adipose-Derived Stem Cells (ADSCs) and Platelet Lysate Plasma (PLP). ADSCs were obtained through abdominal liposuction and PLP was prepared after obtaining blood samples from peripheral veins. Erectile function was evaluated with the International Index of Erectile Function questionnaire (IIEF-5) questionnaire, penile triplex at the 1st, 3rd, 6th and 12th month post-treatment. A CT scan of the head, thorax and abdomen was done before treatment and at the 12th month. Results: IIEF-5 scores were improved in all patients at the 6th month although not in the same pattern in all patients. Peak Systolic Velocity (PSV) also improved at the 6th month in all patients but also with different patterns in each patient, while End Diastolic Velocity (EDV) was more variable. Two patients decreased the treatment they used in order to obtain erection (from Intracavernosal injections (ICI) they used PDE-5Is), two had unassisted erections and one had an initial improvement which decreased at the 6th month. There were no side effects noted. Conclusions: Stem cell therapy in combination with PLP appears to show some improvement in erectile function and has minimal side effects in the short term.

Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model

INTRODUCTION

The human placenta provides a bountiful and noncontroversial source of stem cells which have the potential for regeneration of injured tissue. These cells may restore erectile function after neurovascular tissue injury such as that seen in radical pelvic surgeries and pelvic trauma.

AIM

To determine the effect of human placenta-derived stem cells on erectile function recovery and histological changes at various time points in a cavernous nerve injury rat model and to study the fate of injected stem cells throughout the regenerative process.

METHODS

Human placental stem cells (PSCs) were dual labeled with monomeric Katushka far red fluorescent protein (mKATE)-renLUC using a lentivirus vector. A pelvic neurovascular injury-induced erectile dysfunction model was established in male, athymic rats by crushing the cavernous nerves and ligating the internal pudendal neurovascular bundles, bilaterally. At the time of defect creation, nonlabeled PSCs were injected into the corpus cavernosum at a concentration of 2.5 × 10⁶ cells/0.2 mL. The phosphate-buffered saline-treated group served as the negative control group, and age-matched rats (age-matched controls) were used as the control group. Erectile function, histomorphological analyses, and Western blot were assessed at 1, 6, and 12 weeks after model creation. The distribution of implanted, dual-labeled PSCs was monitored using an in vivo imaging system (IVIS). Implanted cells were further tracked by detection of mKATE fluorescence in histological sections.

MAIN OUTCOME MEASURE

The main outcome measure includes intracavernous pressure/mean arterial pressure ratio, neural, endothelial, smooth muscle cell regeneration, mKATE fluorescence, and IVIS imaging.

RESULTS

The ratio of intracavernous pressure to mean arterial pressure significantly increased in PSC-injected rats compared with phosphate-buffered saline controls (P < 0.05) at the 6- and 12-week time points, reaching 72% and 68% of the age-matched control group, respectively. Immunofluorescence staining and Western blot analysis showed significant increases in markers of neurons (84.3%), endothelial cells (70.2%), and smooth muscle cells (70.3%) by 6 weeks in treatment groups compared with negative controls. These results were maintained through 12 weeks. IVIS analysis showed luminescence of implanted PSCs in the injected corpora immediately after injection and migration of cells to the sites of injury, including the incision site and periprostatic vasculature by day 1. mKATE fluorescence data revealed the presence of PSCs in the penile corpora and major pelvic ganglion at 1 and 3 days postoperatively. At 7 days, immunofluorescence of penile PSCs had disappeared and was diminished in the major pelvic ganglion.

CLINICAL IMPLICATIONS

Placenta-derived stem cells may represent a future "off-the-shelf" treatment to mitigate against development of erectile dysfunction after radical prostatectomy or other forms of pelvic injury.

STRENGTH & LIMITATIONS

Single dose injection of PSCs after injury resulted in maximal functional recovery and tissue regeneration at 6 weeks, and the results were maintained through 12 weeks. Strategies to optimize adult stem cell therapy might achieve more effective outcomes for human clinical trials.

CONCLUSION

Human PSC therapy effectively restores the erectile tissue and function in this animal model. Thus, PSC therapy may provide an attractive modality to lessen the incidence of erectile dysfunction after pelvic neurovascular injury. Further improvement in tissue regeneration and functional recovery may be possible using multiple injections or systemic introduction of stem cells. Gu X, Thakker PU, Matz EL, et al. Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model. J Sex Med 2020;17:400-411.

Adipose-derived stem cells modified by BDNF gene rescue erectile dysfunction after cavernous nerve injury

Cavernous nerve injury is the main cause of erectile dysfunction following radical prostatectomy. The recovery of erectile function following radical prostatectomy remains challenging. Our previous studies found that injecting adipose-derived stem cells (ADSCs) into the cavernosa could repair the damaged cavernous nerves, but the erectile function of the treated rats could not be restored to a normal level. We evaluated the efficacy of ADSCs infected with a lentiviral vector encoding rat brain-derived neurotrophic factor (lenti-rBDNF) in a rat model of cavernous nerve injury. The rats were equally and randomly divided into four groups. In the control group, bilateral cavernous nerves were isolated but not injured. In the bilateral cavernous nerve injury group, bilateral cavernous nerves were isolated and injured with a hemostat clamp for 2 minutes. In the ADSC_GFP and ADSC_rBDNF groups, after injury with a hemostat clamp for 2 minutes, rats were injected with ADSCs infected with lenti-GFP (1 × 10⁶ in 20 μL) and lenti-rBDNF (1 × 10⁶ in 20 μL), respectively. Erectile function was assessed 4 weeks after injury by measuring intracavernosal pressures. Then, penile tissues were collected for histological detection and western blot assay. Results demonstrated that compared with the bilateral cavernous nerve injury group, erectile function was significantly recovered in the ADSC_GFP and ADSC_rBDNF groups, and to a greater degree in the ADSC_rBDNF group. Neuronal nitric oxide synthase content in the dorsal nerves and the ratio of smooth muscle/collagen were significantly higher in the ADSC_rBDNF and ADSC_GFP groups than in the bilateral cavernous nerve injury group. Neuronal nitric oxide synthase expression was obviously higher in the ADSC_rBDNF group than in the ADSC_GFP group. These findings confirm that intracavernous injection with ADSCs infected with lenti-rBDNF can effectively improve erectile dysfunction caused by cavernous nerve injury. This study was approved by the Medical Animal Care and Welfare Committee of Wuhan University, China (approval No. 2017-1638) on June 20, 2017.

Smooth Muscle Progenitor Cells Preserve the Erectile Function by Reducing Corporal Smooth Muscle Cell Apoptosis after Bilateral Cavernous Nerve Crush Injury in Rats

Radical prostatectomy causes erectile dysfunction (ED) and irreversible morphologic changes, including induction of endothelial and smooth muscle cell (SMC) apoptosis in the corpus cavernosum (CC). The injection of smooth muscle progenitor cells (SPCs) thickens the vascular intima and has demonstrated therapeutic benefit in cardiovascular disease animal. Herein, we investigated the effect of SPCs on the recovery of erectile function (EF) in rat models with bilateral cavernous nerve (CN) injury. Twenty-four male Sprague-Dawley rats were randomized into sham, vehicle only, or SPC treatment groups. Rats in the SPC treatment and vehicle groups were subjected to bilateral CN injury before intracavernosal injection. Intracavernosal injections of SPCs increased all EF parameters at day 28 after injury and simultaneously reduced apoptosis of the SMCs. Ultrastructural analysis revealed that SPCs maintained the integrity of the CC by preserving the structure of the adherens junctions. Tracking transplanted SPCs labeled with EdU showed that transplanted SPCs remained in the CC 28 days after treatment. Intracavernosal SPC injection restored EF after bilateral CN injury by reducing SMC apoptosis, which favored the maintenance of the structure of adherens junctions and regulated the stability of corporal vessels. These findings demonstrate the therapeutic potential of SPCs for treating ED in humans.

Dyslipidemia Is a Major Factor in Stem Cell Damage Induced by Uncontrolled Long-Term Type 2 Diabetes and Obesity in the Rat, as Suggested by the Effects on Stem Cell Culture

BACKGROUND

Previous work showed that muscle-derived stem cells (MDSCs) exposed long-term to the milieu of uncontrolled type 2 diabetes (UC-T2D) in male obese Zucker (OZ) rats, were unable to correct the associated erectile dysfunction and the underlying histopathology when implanted into the corpora cavernosa, and were also imprinted with a noxious gene global transcriptional signature (gene-GTS), suggesting that this may interfere with their use as autografts in stem cell therapy.

AIM

To ascertain the respective contributions of dyslipidemia and hyperglycemia to this MDSC damage, clarify its mechanism, and design a bioassay to identify the damaged stem cells.

METHODS

Early diabetes MDSCs and late diabetes MDSCs were respectively isolated from nearly normal young OZ rats and moderately hyperglycemic and severely dyslipidemic/obese aged rats with erectile dysfunction. Monolayer cultures of early diabetic MDSCs were incubated 4 days in DMEM/10% fetal calf serum + or - aged OZ or lean Zucker serum from non-diabetic lean Zucker rats (0.5-5%) or with soluble palmitic acid (PA) (0.5-2 mM), cholesterol (CHOL) (50-400 mg/dL), or glucose (10-25 mM).

MAIN OUTCOME MEASURE

Fat infiltration was estimated by Oil red O, apoptosis by TUNEL, protein expression by Western blots, and gene-GTS and microRNA (miR)-GTS were determined in these stem cells' RNA.

RESULTS

Aged OZ serum caused fat infiltration, apoptosis, myostatin overexpression, and impaired differentiation. Some of these changes, and also a proliferation decrease occurred with PA and CHOL. The gene-GTS changes by OZ serum did not resemble the in vivo changes, but some occurred with PA and CHOL. The miR-GTS changes by OZ serum, PA, and CHOL resembled most of the in vivo changes. Hyperglycemia did not replicate most alterations.

CLINICAL IMPLICATIONS

MDSCs may be damaged in long-term UC-T2D/obese patients and be ineffective in autologous human stem cell therapy, which may be prevented by excluding the damaged MDSCs.

STRENGTH & LIMITATIONS

The in vitro test of MDSCs is innovative and fast to define dyslipidemic factors inducing stem cell damage, its mechanism, prevention, and counteraction. Confirmation is required in other T2D/obesity rat models and stem cells (including human), as well as miR-GTS biomarker validation as a stem cell damage biomarker.

CONCLUSION

Serum from long-term UC-T2D/obese rats or dyslipidemic factors induces a noxious phenotype and miR-GTS on normal MDSCs, which may lead in vivo to the repair inefficacy of late diabetic MDSCs. This suggests that autograft therapy with MDSCs in long-term UT-T2D obese patients may be ineffective, albeit this may be predictable by prior stem cell miR-GTS tests. Masouminia M, Gelfand R, Kovanecz I, et al. Dyslipidemia Is a Major Factor in Stem Cell Damage Induced by Uncontrolled Long-Term Type 2 Diabetes and Obesity in the Rat, as Suggested by the Effects on Stem Cell Culture. J Sex Med 2018;15:1678-1697.

Nanotechnology-assisted adipose-derived stem cell (ADSC) therapy for erectile dysfunction of cavernous nerve injury: In vivo cell tracking, optimized injection dosage, and functional evaluation

Stem cell therapy is a potentially promising option for erectile dysfunction; however, its risk of tumorigenicity is a clinical hurdle and the risk is positively related to the number of injected cells. Our previous study showed that nanotechnology improved adipose-derived stem cell (ADSC) therapy for erectile dysfunction of cavernous nerve injury (CNI) by attracting cells in the corpus cavernosum. These results indicated the possibility of using a reduced dosage of ADSCs for intracavernous injection. In this exploratory study, we used lower dosage (2 × 10⁵ cells) of ADSCs for intracavernous injection (ICI) and the nanotechnology approach. Intracavernous pressure and mean arterial pressure were measured at day 28 to assess erectile function. The low-dose ADSC therapy group showed favorable treatment effects, and nanotechnology further improved these effects. In vivo imaging of ICI cells revealed that the fluorescein signals of NanoShuttle-bound ADSCs (NanoADSCs) were much stronger than those of ADSCs at days 0, 1, and 3. Both immunofluorescence and Western blot analysis showed a significant increase in smooth muscle, endothelium, and nerve tissue in the ADSC group compared to that in the CNI group; further improvement was achieved with assisted nanotechnology. These findings demonstrate that nanotechnology can be used to further improve the effect of small dosage of ADSCs to improve erectile function. Abundant NanoADSCs remain in the corpus cavernosum in vivo for at least 3 days. The mechanism of erectile function improvement may be related to the regeneration of the smooth muscle, endothelium, and nerve tissues.

Administration of Adipose Derived Mesenchymal Stem Cells and Platelet Lysate in Erectile Dysfunction: A Single Center Pilot Study

Erectile dysfunction (ED) affects more than 30 million men; endothelial dysfunction plays a significant role in EDs pathogenesis. The aim of this study was to administer mesenchymal stem cells (MSC) derived from adipose tissue and platelet lysate (PL) into patients with erectile dysfunction. This pilot study enrolled eight patients with diagnosed ED. Patients enrolled were suffering from organic ED due to diabetes melitus, hypertension, hypercholesterolaemia, and Peyronie disease. The patients were distributed in 2 groups. Patients in group A received adipose derived mesenchymal stem cells (ADMSC) resuspended in PL while patients in group B received only PL. ADMSCs were isolated from patients' adipose tissue and expanded. In addition, blood sampling was obtained from the patients in order to isolate platelet lysate. After the application of the above treatments, patients were evaluated with an International Index of Erectile Function (IIEF-5) questionnaire, penile triplex, and reported morning erections. After MSCs and PL administration, patients presented improved erectile function after 1 and 3 months of follow-up. A statistically significant difference was observed in the IIEF-5 score before and after administration of both treatments after the first month (p < 0.05) and the third month (p < 0.05). No statistically significant difference was observed in the IIEF-5 score between group A and B patients. All patients were characterized by improved penile triplex and increased morning erections. No severe adverse reactions were observed in any patient except a minor pain at the site of injection, which was in the limits of tolerability. The results of this study indicated the satisfactory use of MSCs and PL in ED. MSCs in combination with PL or PL alone seems to be very promising, especially without having the negative effects of the current therapeutic treatment.

Emerging nonsurgical and surgical techniques to treat erectile dysfunction: A systematic review of treatment options and published outcomes

Erectile dysfunction (ED) is one of the most common causes of morbidity in male patients, with a prevalence of 50-60% in men aged 40-70 years. EDs may be caused by physical or psychological trauma, the former of which may be treatable through surgical intervention. Physical trauma may be further categorized as vasculogenic, neurogenic, or idiopathic in nature. Although many patients do not respond well to nonsurgical treatment options, few opt for surgical intervention. This is likely due to the difficulty of the procedures, as well as relatively low historical success rates. As such, a systematic review of the literature was performed to identify novel surgical interventions for ED. A total of 19 manuscripts were included in this review, representing data of three minimally invasive approaches to ED treatment and seven novel surgical techniques. The data revealed compelling evidence in support of microsurgical treatments for ED - namely, microvascular arterial bypass penile revascularization surgery (MABS) and cavernous nerve graft reconstruction. Nerve grafts varied, with the use of end-to-side ilioinguinal, genitofemoral, and sural grafts, all demonstrating high rates of success. Furthermore, minimally invasive botulinum toxin (BoNT-A) treatment and adipose-derived stem cell (ADSC) therapy have shown extreme promise in rat models; with BoNT-A treatment entering phase II human clinical trials this year. Many of the surgical methods investigated in this review are microsurgical interventions that demonstrate high rates of success in patients with neurogenic or vasculogenic ED. As such, microsurgeons are uniquely trained and positioned to be of value to ED treatment.

Whole genome mRNA expression profiling revealed multiple deregulated pathways in stromal vascular fraction from erectile dysfunction patients

Background: Stem-cell-based therapies have recently been explored in the field of erectile dysfunction (ED). However, the cellular and molecular phenotype of adipose derived stem cells (ADSCs) stromal vascular fraction (SVF) from ED patients remains largely unknown. Herein we compared the global gene expression profile in the SVF from ED patients and healthy individuals and identified altered signaling pathways between the two groups.

Methods: Samples (2–5 g) of abdominal adipose tissue from ED patients (n = 6) and healthy individual controls (n = 3) undergoing elective cosmetic liposuction were collected. Immediately after removal, SVF was separated using Collagenase type I and type IV protocol. RNA was isolated and microarray experiments were conducted using the Agilent platform. Data were normalized and pathway analyses were performed using GeneSpring software.

Results: Our data revealed multiple differentially expressed genes between the ED and control group. Hierarchical clustering based on differentially expressed mRNAs revealed clear separation of the two groups. The distribution of the top enriched pathways for the up-regulated genes indicated enrichment in inflammatory response and T-cell receptor signaling, while pathway analysis performed on the down-regulated genes revealed enrichment in mitogen-activated protein kinase, TGF-β, senescence, FAK, adipogenesis, androgen receptor, and EGF–EGFR signaling pathways in SVF from ED patient.

Conclusion: Our data revealed the existence of multiple altered signaling pathways in the SVF from ED patients, which could potentially play a role in the etiology of this disease. Therefore, therapeutic strategies targeting these pathways might provide novel therapeutic opportunity for ED patients.

Erectile dysfunction treated with intracavernous stem cells: A promising new therapy?

In the past decades, great interest has been shown in the development of new therapies for erectile dysfunction. Stem cell therapy has generated promising results in numerous preclinical trials in animal models, which is why has led to the development of the first clinical trials in humans. The main cause involved in the pathophysiology of erectile dysfunction is vascular damage related to endothelial and neuronal injury. The interest in stem cell therapy is justified by their capability to differentiate into specific damaged tissues, including endothelium and nervous tissue, and induction of the host own cell proliferation. Despite the great effort of the many studies carried out to date, knowledge about biological effects, therapeutic efficacy and safety of stem cells therapy for erectile dysfunction is still very limited.

Successful Use of an Inflatable Penile Prosthesis for the Treatment of Distal Deficiency of the Tunica Albuginea and Cavernous Tissue

Introduction

Congenital hypoplasia of the distal half of the tunica albuginea has not been previously described.

Aim

To review a patient presenting with erectile dysfunction secondary to congenital penile hypoplasia.

Methods

History, physical exam and penile Doppler ultrasound of the patient, followed by a discussed of treatment options and definitive management.

Results

Successful operative treatment of our patient with insertion of an inflatable penile prosthesis.

Conclusion

We present a case of congenital hypoplasia of the distal tunica albuginea and a successful treatment strategy. We highlight the need for further study of penile embryology.

Punjani N, McGarry P, Brock G. Successful Use of an Inflatable Penile Prosthesis for the Treatment of Distal Deficiency of the Tunica Albuginea and Cavernous Tissue. Sex Med 2018;6:356–359.

Effects of light-emitting diodes irradiation on human vascular endothelial cells

Endothelial cell proliferation is a hallmark of angiogenesis and plays a key role in the process of tissue repair. Low-intensity (670 nm) laser irradiation influences endothelial cell proliferation in vitro. Light in the near infrared spectrum may have clinical applications in erectile dysfunction. The purpose of this study was to investigate the effects of irradiation with light-emitting diodes (LEDs) at different wavelengths on human vascular endothelial cells in vitro. Human umbilical vein endothelial cells (HUVECs) were irradiated with LEDs at 410, 480, 595, and 630 nm in doses of 1, 2.5, 5, and 10 J/cm². After 24 h of LED irradiation, effects on cell viability, nitric oxide (NO) secretion, and eNOS expression were assessed by using cell viability assays, Western blot, and real time-polymerase chain reaction, respectively. The cell viability assay demonstrated that irradiation with LEDs at 630 nm significantly increased the proliferation of HUVECs. In addition, irradiation with LEDs at 630 nm was more effective in stimulating NO secretion and eNOS expression from HUVECs than irradiation with LEDs at 410, 480, and 595 nm. Irradiation with LEDs at 630 nm was effective for inducing cell proliferation, NO secretion, and eNOS expression in HUVECs. These results suggest that irradiation with LEDs at 630 nm may be a therapeutic strategy for vasculogenic erectile dysfunction.

Neuroprotective and Nerve Regenerative Approaches for Treatment of Erectile Dysfunction after Cavernous Nerve Injury

Erectile dysfunction (ED) is a significant cause of reduced quality of life in men and their partners. Cavernous nerve injury (CNI) during pelvic surgery results in ED in greater than 50% of patients, regardless of additional patient factors. ED related to CNI is difficult to treat and typically poorly responsive to first- and second-line therapeutic options. Recently, a significant amount of research has been devoted to exploring neuroprotective and neuroregenerative approaches to salvage erectile function in patients with CNI. In addition, therapeutic options such as neuregulins, immunophilin ligands, gene therapy, stem cell therapy and novel surgical strategies, have shown benefit in pre-clinical, and limited clinical studies. In the era of personalized medicine, these new therapeutic technologies will be the future of ED treatment and are described in this review.