Exosome Released From Schwann Cells May Be Involved in Microenergy Acoustic Pulse-Associated Cavernous Nerve Regeneration

The correlation between premature ejaculation and a high incidence of erectile dysfunction and its research progress: a narrative review

Background and Objective

Premature ejaculation (PE) and erectile dysfunction (ED) are two common sexual symptoms of male sexual dysfunction that can strongly affect men's mental health and quality of life, and they often coexist. This aim of this study was to explore the causes and relationships between PE and ED, with a focus on the progression of PE accompanied by high-frequency ED. A deeper understanding of the causes and treatments for PE combined with ED will help improve clinical diagnosis and treatment.

Methods

We conducted a literature review of the most relevant articles related to the outlined topic in the PubMed, Google Scholar, and Web of Science databases. We did not limit language, covering both English and non-English publications, and include Chinese and English papers published between January 1996 and March 2024.

Key Content and Findings

The incidence of PE and ED increases with age. Approximately one-third of patients who complain of ED suffer from PE. Similarly, in a large-scale survey in the Asia-Pacific region, more than 30% of patients with PE reported concurrent ED. Various research findings indicate a strong correlation between PE and ED. Some scholars speculate that there is a vicious cycle between PE and ED. Men who attempt to control ejaculation can reduce the level of arousal, leading to ED, whereas men who try to achieve an erection will attempt to increase the level of arousal, which can lead to PE. This cycle of mutual influence may lead to reciprocal aggravation and persistence of sexual dysfunction in both parties. Although some studies have explored the relationship between PE and ED, the specific determinants and underlying factors have not yet been clarified.

Conclusions

There is a close interrelationship between PE and ED, and a vicious cycle may exist between the two. This cycle of mutual influence may lead to the mutual aggravation and persistence of both sexual dysfunctions. However, the specific determining factors and potential factors underlying the correlation between the two have not been clearly identified and require further exploration.

Proceedings of PRINCETON IV: PDE5 inhibitors and cardiac health symposium

INTRODUCTION

Prior consensus meetings have addressed the relationship between phosphodiesterase type 5 (PDE5) inhibition and cardiac health. Given significant accumulation of new data in the past decade, a fourth consensus conference on this topic was convened in Pasadena, California, on March 10 and 11, 2023.

OBJECTIVES

Our meeting aimed to update existing knowledge, assess current guidelines, and make recommendations for future research and practice in this area.

METHODS

An expert panel reviewed existing research and clinical practice guidelines.

RESULTS

Key findings and clinical recommendations are the following: First, erectile dysfunction (ED) is a risk marker and enhancer for cardiovascular (CV) disease. For men with ED and intermediate levels of CV risk, coronary artery calcium (CAC) computed tomography should be considered in addition to previous management algorithms. Second, sexual activity is generally safe for men with ED, although stress testing should still be considered for men with reduced exercise tolerance or ischemia. Third, the safety of PDE5 inhibitor use with concomitant medications was reviewed in depth, particularly concomitant use with nitrates or alpha-blockers. With rare exceptions, PDE5 inhibitors can be safely used in men being treated for hypertension, lower urinary tract symptoms and other common male disorders. Fourth, for men unresponsive to oral therapy or with absolute contraindications for PDE5 inhibitor administration, multiple treatment options can be selected. These were reviewed in depth with clinical recommendations. Fifth, evidence from retrospective studies points strongly toward cardioprotective effects of chronic PDE5-inhibitor use in men. Decreased rates of adverse cardiac outcomes in men taking PDE-5 inhibitors has been consistently reported from multiple studies. Sixth, recommendations were made regarding over-the-counter access and potential risks of dietary supplement adulteration. Seventh, although limited data exist in women, PDE5 inhibitors are generally safe and are being tested for use in multiple new indications.

CONCLUSION

Studies support the overall cardiovascular safety of the PDE5 inhibitors. New indications and applications were reviewed in depth.

Research progress on the therapeutic application of extracellular vesicles in erectile dysfunction

Erectile dysfunction (ED) is one of the most common male sexual dysfunctions and is related to many pathogenic factors. However, first-line treatment, represented by phosphodiesterase 5 inhibitors, is unable to maintain long-term efficacy. Extracellular vesicles (EVs) have recently attracted the attention of researchers in the fields of cardiovascular disease, neurologic disease, and regenerative medicine and may become a treatment for ED. This article reviews recent applications of EVs in the treatment of ED from the aspects of the source, the therapeutic mechanism, and the strategies to enhance therapeutic efficacy. These research advances lay the foundation for further research and provide references for in-depth understanding of the therapeutic mechanism and possible clinical application of EVs in ED.

Safety of low-intensity extracorporeal shock wave therapy in prostate disorders: in vitro and in vivo evidence

ABSTRACT

Recent evidence suggests that low-intensity extracorporeal shock wave therapy (Li-ESWT) is a promising treatment for chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS); however, its safety in pelvic organs, particularly prostate tissues and cells, remains unclear. The current study evaluates the risks of prostate cell damage or oncogenesis following the administration of Li-ESWT for prostatitis. To this end, a robust in vitro model (Cell Counting Kit-8 [CCK-8] assay, clone formation assay, cell scratch assay, lactate dehydrogenase [LDH] release assay, flow cytometry, and immunoblotting assay) was designed to examine the effects of Li-ESWT on cell proliferation, clonogenicity, migration, membrane integrity, and DNA damage. Exome sequencing of Li-ESWT-treated cells was performed to determine the risk of carcinogenesis. Furthermore, an in vivo rat model ( n = 20) was employed to assess the effects of Li-ESWT on cancer biomarkers (carcinoembryonic antigen [CEA], Ki67, proliferating cell nuclear antigen [PCNA], and gamma-H2A histone family member X, phosphorylation of the H2AX Ser-139 [ γ -H2AX]) in prostate tissue. Based on our findings, Li-ESWT promotes cellular growth and motility without inducing significant cell membrane or DNA damage or alterations. Genetic analyses did not demonstrate an increase in mutations, and no damage to prostate tissue or upregulation of cancer biomarkers was detected in vivo. This comprehensive in vitro and in vivo assessment confirms the safety of Li-ESWT in managing prostate disorders.

Princeton IV consensus guidelines: PDE5 inhibitors and cardiac health

BACKGROUND

In 1999, 1 year after the approval of the first oral phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), the first Princeton Consensus Conference was held to address the clinical management of men with ED who also had cardiovascular disease. These issues were readdressed in the second and third conferences. In the 13 years since the last Princeton Consensus Conference, the experience with PDE5 inhibitors is more robust, and recent new data have emerged regarding not only safety and drug-drug interactions, but also a potential cardioprotective effect of these drugs.

AIM

In March 2023, an interdisciplinary group of scientists and practitioners met for the fourth Princeton Consensus Guidelines at the Huntington Medical Research Institutes in Pasadena, California, to readdress the cardiovascular workup of men presenting with ED as well as the approach to treatment of ED in men with known cardiovascular disease.

METHOD

A series of lectures from experts in the field followed by Delphi-type discussions were developed to reach consensus.

OUTCOMES

Consensus was reached regarding a number of issues related to erectile dysfunction and the interaction with cardiovascular health and phosphodiesterase-5 inhibitors.

RESULTS

An algorithm based on recent recommendations of the American College of Cardiology and American Heart Association, including the use of computed tomography coronary artery calcium scoring, was integrated into the evaluation of men presenting with ED. Additionally, the issue of nitrate use was further considered in an algorithm regarding the treatment of ED patients with coronary artery disease. Other topics included the psychological effect of ED and the benefits of treating it; the mechanism of action of the PDE5 inhibitors; drug-drug interactions; optimizing use of a PDE5 inhibitors; rare adverse events; potential cardiovascular benefits observed in recent retrospective studies; adulteration of dietary supplements with PDE5 inhibitors; the pros and cons of over-the-counter PDE5 inhibitors; non-PDE5 inhibitor therapy for ED including restorative therapies such as stem cells, platelet-rich plasma, and shock therapy; other non-PDE5 inhibitor therapies, including injection therapy and penile prostheses; the issue of safety and effectiveness of PDE5 inhibitors in women; and recommendations for future studies in the field of sexual dysfunction and PDE5 inhibitor use were discussed.

CLINICAL IMPLICATIONS

Algorithms and tables were developed to help guide the clinician in dealing with the interaction of ED and cardiovascular risk and disease.

STRENGTHS AND LIMITATIONS

Strengths include the expertise of the participants and consensus recommendations. Limitations included that participants were from the United States only for this particular meeting.

CONCLUSION

The issue of the intersection between cardiovascular health and sexual health remains an important topic with new studies suggesting the cardiovascular safety of PDE5 inhibitors.

Exosome-based regenerative rehabilitation: A novel ice breaker for neurological disorders

Neurological disorders affect a large population, often leading to different levels of disability and resulting in decreased quality of life. Due to the limited recovery obtained from surgical procedures and other medical approaches, a large number of patients with prolonged dysfunction receive neurorehabilitation protocols to improve their neural plasticity and regeneration. However, the poor neural regeneration ability cannot effectively rebuild the tissue integrity and neural functional networks; consequently, the prognoses of neurorehabilitation remain undetermined. To increase the chances of neural regeneration and functional recovery for patients with neurological disorders, regenerative rehabilitation was introduced with combined regenerative medicine and neurorehabilitation protocols to repair neural tissue damage and create an optimized biophysical microenvironment for neural regeneration potential. With the deepening of exosome research, an increasing number of studies have found that the systemic therapeutic effects of neurorehabilitation approaches are mediated by exosomes released by physically stimulated cells, which provides new insight into rehabilitative mechanisms. Meanwhile, exosome therapy also serves as an alternative cell-free therapy of regenerative medicine that is applied in partnership with neurorehabilitation approaches and formulates exosome-based neurological regenerative rehabilitation. In this study, we review the current state of exosome-associated neurorehabilitation. On the one hand, we focus on presenting the varied mediating effects of exosomes in neurorehabilitation protocols of specific neurological pathologies; on the other hand, we discuss the diverse combinations of exosome therapies and neurorehabilitation approaches in the field of neurological regenerative rehabilitation, aiming to increase the awareness of exosome research and applications in the rehabilitation of neurological disorders.

Neurobiological insights into lower urinary tract dysfunction: evaluating the role of brain-derived neurotrophic factor

Lower urinary tract dysfunction (LUTD) encompasses a range of debilitating conditions that affect both sexes and different age groups. Understanding the underlying neurobiological mechanisms contributing to LUTD has emerged as a critical avenue for the development of targeted therapeutic strategies. Brain-derived neurotrophic factor (BDNF), a prominent member of the neurotrophin family, has attracted attention due to its multiple roles in neural development, plasticity, and maintenance. This review examines the intricate interplay between neurobiological factors and LUTD, focusing on the central involvement of BDNF. The review emphasizes the bidirectional relationship between LUTD and BDNF and explores how LUTD-induced neural changes may affect BDNF dynamics and vice versa. Growth factor therapy and the combined administration of controlled release growth factors and stem cells are minimally invasive treatment strategies for neuromuscular injury. Among the many growth factors and cytokines, brain-derived neurotrophic factor (BDNF) plays a prominent role in neuromuscular repair. As an essential neurotrophin, BDNF is involved in the modulation of neuromuscular regeneration through tropomyosin receptor kinase B (TrkB). Increasing BDNF levels facilitates the regeneration of the external urethral sphincter and contributes to the regulation of bladder contraction. Treatments targeting the BDNF pathway and sustained release of BDNF may become novel treatment options for urinary incontinence and other forms of lower urinary tract dysfunction. This review discusses the applications of BDNF and the theoretical basis for its use in the treatment of lower urinary tract dysfunction, including urinary incontinence (UI), overactive bladder (OAB), and benign prostatic hyperplasia (BPH), and in the clinical diagnosis of bladder dysfunction.

LIPUS-SCs-Exo promotes peripheral nerve regeneration in cavernous nerve crush injury-induced ED rats via PI3K/Akt/FoxO signaling pathway

OBJECTIVE

Clinical treatment of erectile dysfunction (ED) caused by cavernous nerve (CN) injury during pelvic surgery is difficult. Low-intensity pulsed ultrasound (LIPUS) can be a potential strategy for neurogenic ED (NED). However, whether Schwann cells (SCs) can respond to LIPUS stimulation signals is unclear. This study aims to elucidate the signal transmission between SCs paracrine exosome (Exo) and neurons stimulated by LIPUS, as well as to analyze the role and potential mechanisms of exosomes in CN repair after injury.

METHODS

The major pelvic ganglion (MPG) neurons and MPG/CN explants were stimulated with LIPUS of different energy intensities to explore the appropriate LIPUS energy intensity. The exosomes were isolated and purified from LIPUS-stimulated SCs (LIPUS-SCs-Exo) and non-stimulated SCs (SCs-Exo). The effects of LIPUS-SCs-Exo on neurite outgrowth, erectile function, and cavernous penis histology were identified in bilateral cavernous nerve crush injury (BCNI)-induced ED rats.

RESULTS

LIPUS-SCs-Exo group can enhance the axon elongation of MPG/CN and MPG neurons compared to SCs-Exo group in vitro. Then, the LIPUS-SCs-Exo group showed a stronger ability to promote the injured CN regeneration and SCs proliferation compared to the SCs-Exo group in vivo. Furthermore, the LIPUS-SCs-Exo group increased the Max intracavernous pressure (ICP)/mean arterial pressure (MAP), lumen to parenchyma and smooth muscle to collagen ratios compared to the SCs-Exo group in vivo. Additionally, high-throughput sequencing combined with bioinformatics analysis revealed the differential expression of 1689 miRNAs between the SCs-Exo group and the LIPUS-SCs-Exo group. After LIPUS-SCs-Exo treatment, the phosphorylated levels of Phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt) and forkhead box O (FoxO) in MPG neurons increased significantly compared to negative control (NC) and SCs-Exo groups.

CONCLUSION

Our study revealed that LIPUS stimulation could regulate the gene of MPG neurons by changing miRNAs derived from SCs-Exo, then activating the PI3K-Akt-FoxO signal pathway to enhance nerve regeneration and restore erectile function. This study had important theoretical and practical significance for improving the NED treatment.

Low-intensity pulsed ultrasound ameliorates erectile dysfunction induced by bilateral cavernous nerve injury through enhancing Schwann cell-mediated cavernous nerve regeneration

BACKGROUND

Cavernous nerve injury-induced erectile dysfunction caused by pelvic surgery or trauma is refractory to conventional medications and required an alternative treatment. Low-intensity pulsed ultrasound is a noninvasive mechanical therapy that promotes nerve regeneration.

OBJECTIVES

To investigate the therapeutic effect and potential mechanism of low-intensity pulsed ultrasound in the treatment of neurogenic erectile dysfunction.

MATERIALS AND METHODS

Thirty rats were randomly divided into the sham-operated group, bilateral cavernous nerve injury group, and bilateral cavernous nerve injury + low-intensity pulsed ultrasound group. The erectile function was assessed 3 weeks after daily low-intensity pulsed ultrasound treatment. The penile tissues and cavernous nerve tissues were harvested and subjected to histologic analysis. Primary Schwann cells and explants were extracted from adult rats. The effects of low-intensity pulsed ultrasound on proliferation, migration, and nerve growth factor expression of Schwann cells and axonal elongation were examined in vitro. RNA sequencing and western blot assay were applied to predict and verify the molecular mechanism of low-intensity pulsed ultrasound-induced Schwann cell activation.

RESULTS

Our study showed that low-intensity pulsed ultrasound promoted Schwann cells proliferation, migration, and neurotrophic factor nerve growth factor expression. Meanwhile, low-intensity pulsed ultrasound exhibits a stronger ability to enhance Schwann cells-mediated neurite outgrowth of major pelvic ganglion neurons and major pelvic ganglion/cavernous nerve explants in vitro. In vivo experiments demonstrated that the erectile function of the rats in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group was significantly higher than those in the bilateral cavernous nerve injury groups. Moreover, the expression levels of smooth muscle and cavernous endothelium also increased significantly in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group. In addition, we observed the higher density and number of cavernous nerve regenerating axons in the bilateral cavernous nerve injury + low-intensity pulsed ultrasound group, indicating that low-intensity pulsed ultrasound promotes axonal regeneration following cavernous nerve injury in vivo. RNA sequencing analysis and bioinformatic analysis suggested that low-intensity pulsed ultrasound might trigger the activation of the PI3K/Akt pathway. Western blot assay confirmed that low-intensity pulsed ultrasound activated Schwann cells through TrkB/Akt/CREB signaling.

CONCLUSIONS

Low-intensity pulsed ultrasound promoted nerve regeneration and ameliorated erectile function by enhancing Schwann cells proliferation, migration, and neurotrophic factor nerve growth factor expression. The TrkB/Akt/CREB axis is the possible mechanism of low-intensity pulsed ultrasound-mediated Schwann cell activation. Low-intensity pulsed ultrasound-based therapy could be a novel potential treatment strategy for cavernous nerve injury-induced neurogenic erectile dysfunction.

Fermented Gynochthodes officinalis (F.C.How) Razafim. & B.Bremer alleviates diabetic erectile dysfunction by attenuating oxidative stress and regulating PI3K/Akt/eNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, Gynochthodes officinalis (F.C.How) Razafim. & B.Bremer (G. officinalis) has been historically as tonics to treat impotence. Fermentation is an ancient processing method for traditional Chinese medicine. Whether fermentation affects the therapeutic effects of G. officinalis on diabetic erectile dysfunction has so far remained unknown.

AIMS OF THE STUDY

In this research, we aim to determine the effect of fermented or unfermented G. officinalis root extract on diabetes mellitus-induced erectile dysfunction (DMED) and the potential mechanisms.

MATERIALS AND METHODS

Candida sp. B5, Lactobacillus sp. Y5 and Lactobacillus sp. R2 are applied for the fermentation of G. officinalis. The optimum fermentation conditions of G. officinalis are investigated. Sprague-Dawley rats were used to establish a diabetic erectile dysfunction model, treated with different concentrations of fermented or unfermented G. officinalis, to compare the effect of fermented or unfermented G. officinalis on DMED and explore underlying mechanisms by assessment of intracavernous pressure, ELISA, Western blot, Masson's trichrome staining, and immunofluorescence. The corpus cavernosum smooth muscle cells (CCSMCs) and Schwann cells were isolated and used to investigate the effect of fermented or unfermented G. officinalis on hydrogen peroxide (H₂O₂)-induced apoptosis.

RESULTS

The results reveal the optimum fermentation conditions of G. officinalis using Lactobacillus sp. Y5 were determined to be 35 °C, the ratio of solid to liquid 1:10, and six days of fermentation. The fermentation increases the abundance of major active ingredients within G. officinalis. After fermented or unfermented G. officinalis treatment for eight weeks by oral gavage at a dose of 100 mg kg^-1 or 300 mg kg^-1, the results show that the fermentation enhances the effect of G. officinalis on diabetic erectile dysfunction detected by intracavernous pressure. The protein expressions of the PI3K/Akt/eNOS pathway were upregulated in diabetic rats after fermented or unfermented G. officinalis treatment, while the level of oxidative stress was significantly reduced. Meanwhile, Masson's trichrome staining also displayed an improvement in the ratio of smooth muscle to collagen. In vitro experiments confirmed that fermented or unfermented G. officinalis protected CCSMCs and Schwann cells from apoptosis. In contrast, fermented G. officinalis showed a fortified protective effect over unfermented G. officinalis.

CONCLUSION

Our findings suggest that fermentation can increase the composition of main active ingredients in G. officinalis and enhance its role in diabetic erectile dysfunction. It augurs the potential therapeutic application of fermented G. officinalis well for treating diabetic erectile dysfunction.

Cisplatin causes erectile dysfunction by decreasing endothelial and smooth muscle content and inducing cavernosal nerve senescence in rats

INTRODUCTION

Cisplatin (cis-diamminedichloroplatinum II, CDDP), a drug widely used for cancer worldwide, may affect erectile function, but its side effects have not received enough attention. To investigate the effect of CDDP on erectile function and its possible mechanism.

METHODS

Sprague-Dawley rats were intraperitoneally administered CDDP (CDDP group) or the same volume of normal saline (control group). Erectile function was evaluated after a one-week washout. Then, histologic changes in the corpus cavernosum and cavernous nerve (CN) were measured. Other Sprague-Dawley rats were used to isolate the major pelvic ganglion and cavernous nerve (MPG/CN). RSC96 cells were then treated with CDDP. SA-β-gal staining was used to identify senescent cells, and qPCR was used to detect the senescence-associated secretory phenotype (SASP). Finally, the supernatant of RSC96 cells was used to culture MPG/CN. Erectile function was measured after administration of CDDP. The cavernosum levels of α-SMA, CD31, eNOS, and γ-H2AX, the apoptosis rate and the expression of p16, p21 and p53 in CN were also assayed. The senescent phenotype of RSC96 cells treated with CDDP was identified, and neurite growth from the MPG/CN was photographed and measured.

RESULTS

The CDDP group had a significantly lower ICP/MAP ratio than the control group. Compared to the control group, the CDDP group exhibited significantly lower α-SMA, CD31 and eNOS levels and significantly higher γ-H2AX and apoptosis rates in corpus cavernosum. In addition, CDDP increased some senescence markers p16, p21 and p53 in CN. In vitro, CDDP induced RSC96 senescence and SASP, and the supernatant of senescent cells slowed neurite outgrowth of MPG/CN.

DISCUSSIONS

CDDP treatment could induce erectile dysfunction, by affecting the content of endothelial and smooth muscle and causing SASP in CN. The results indicate that CDDP treatment should be considered as a risk factor for ED. Clinicians should pay more attention to the erectile function of cancer patients who receive CDDP treatment.

Erectile dysfunction and exosome therapy

Erectile dysfunction (ED), as a common male disease, can seriously reduce the life quality of men and their partners. With the improvement of human living standards, ED is considered to be an important health issue that plagues men. However, it is difficult for existing therapeutic approaches to meet the needs of all patients, so it is necessary to develop novel treatment strategies. Exosomes, as a class of vesicles secreted by cells with bilayer membrane structure, are involved in various physiological and pathological processes in human body and considered to have great therapeutic potentials. This review summarizes the recent advances on exosome therapy with animal models of ED, and proposes the prospect of future research in order to provide a basis for clinical trials and clinical translation.

Molecular pathogenesis and treatment of cavernous nerve injury-induced erectile dysfunction: A narrative review

Introduction: Erectile dysfunction (ED) is a common complication after radical prostatectomy (RP), and it seriously affects the quality of life in patients and their partners. The primary trigger of postoperative ED is surgical injury to the cavernous nerves that control penile erection and run along the anterolateral aspect of the prostate. Despite the introduction and ongoing innovation of nerve-sparing techniques, a significant number of patients still suffer from moderate cavernous nerve injury (CNI), which is thought to be transient and reversible. Therefore, early postoperative penile rehabilitation therapy may salvage patients’ erectile function by promoting cavernous nerve regeneration and preventing penile structural alterations.

Aims: To present a comprehensive overview of the current molecular pathogenesis of CNI-induced ED, as well as novel therapeutic strategies and their potential mechanisms.

Methods: A literature search was performed using PubMed. Search terms included erectile dysfunction, cavernous nerve injury, pathogenesis, pathway, and treatment.

Results: The NOS/NO pathway, oxidative stress-related pathway, RhoA/ROCK pathway, transforming growth factor-β (TGF-β), sonic hedgehog (Shh), and hydrogen sulfide (H2S) are involved in the molecular pathogenesis of CNI-induced ED. Multiple neurotrophins, including brain-derived nerve growth factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and neurturin (NTN), were found to promote cavernous nerve regeneration. Emerging therapeutic approaches can be roughly summarized into four categories, namely small molecule and drug, stem cell-based therapy (SCT), micro-energy therapy and platelet-rich plasma (PRP) therapy.

Conclusion: These pathways collectively lead to the irreversible damage to the penile structure after CNI. The combined early rehabilitation strategies of promoting upstream nerve regeneration and recovering abnormal molecular signals of downstream penis are presumed to save patients’ erectile function after RP. In future studies, the cross-talk between these molecular pathways needs to be further clarified, and the questions of how denervation injury induces the molecular alterations in the penis also need to be addressed.

The Efficacy and Safety of Thrice vs Twice per Week Low-Intensity Pulsed Ultrasound Therapy for Erectile Dysfunction: A Randomized Clinical Trial

BACKGROUND

A recent sham-controlled clinical study has shown that low-intensity pulsed ultrasound twice per week can safely and effectively treat patients with mild-to-moderate erectile dysfunction (ED). However, large-scale clinical trials are needed to verify its efficacy and safety and determine a reasonable treatment interval.

AIM

To study whether low-intensity pulsed ultrasound therapy thrice per week is non-inferior to twice per week in patients with mild-to-moderate ED.

METHODS

A randomized, open-label, parallel-group, non-inferiority clinical trial was conducted in 7 hospitals in China. A total of 323 patients with mild-to-moderate ED were randomized (1:1) into thrice per week (3/W) and twice per week (2/W) groups. Low-intensity pulsed ultrasound was applied on each side of the penis for 16 sessions.

OUTCOMES

The primary outcome was response rate using the minimal clinically important difference in the International Index of Erectile Function (IIEF-EF) score at week 12. Secondary outcomes included Erection Hardness Score (EHS), Sexual Encounter Profile, Global Assessment Question, and Self Esteem and Relationship Questionnaire.

RESULTS

Response rates in 3/W and 2/W groups were 62.0% and 62.5%, respectively. Treatment effect in the 3/W group was noninferior to that of the 2/W group, with rate difference lower bound of -0.01% [95% confidence interval -0.11 to 0.10%] within the acceptable margin (-14.0%). No significant difference was found among secondary outcomes. IIEF-EF score showed a significant increase from baseline in the 3/W group (16.8 to 20.7) and 2/W group (17.8 to 21.7), and the percentage of patients with EHS ≥3 increased in the 3/W (54.9% to 84.0%) and 2/W (59.5% to 83.5%) groups. There was no significant difference in response rate between the 2 groups after controlling for strata factors and homogeneous tests. No treatment-related adverse events were reported.

CLINICAL IMPLICATIONS

Low-intensity pulsed ultrasound therapy displays similar efficacy and safety for mild-to-moderate ED when administered thrice or twice per week for 16 sessions. This study provides two options to suit patients' needs.

STRENGTHS & LIMITATIONS

This is a large-sample, randomized, controlled, noninferiority trial study. Short-term follow-up and mostly younger patients are the main limitations.

CONCLUSION

Low-intensity pulsed ultrasound therapy thrice and twice per week showed equivalent therapeutic effects and safety for mild-to-moderate ED in a young and generally healthy population. This therapy warrants further investigation of its potential value in rehabilitation of ED.

The Role of Extracellular Vesicles in Cancer-Nerve Crosstalk of the Peripheral Nervous System

Although the pathogenic operations of cancer–nerve crosstalk (e.g., neuritogenesis, neoneurogensis, and perineural invasion—PNI) in the peripheral nervous system (PNS) during tumorigenesis, as well as the progression of all cancer types is continuing to emerge as an area of unique scientific interest and study, extensive, wide-ranging, and multidisciplinary investigations still remain fragmented and unsystematic. This is especially so in regard to the roles played by extracellular vesicles (EVs), which are lipid bilayer-enclosed nano- to microsized particles that carry multiple-function molecular cargos, facilitate intercellular communication in diverse processes. Accordingly, the biological significance of EVs has been greatly elevated in recent years, as there is strong evidence that they could contribute to important and possibly groundbreaking diagnostic and therapeutic innovations. This can be achieved and the pace of discoveries accelerated through cross-pollination from existing knowledge and studies regarding nervous system physiology and pathology, as well as thoroughgoing collaborations between oncologists, neurobiologists, pathologists, clinicians, and researchers. This article offers an overview of current and recent past investigations on the roles of EVs in cancer–nerve crosstalk, as well as in neural development, physiology, inflammation, injury, and regeneration in the PNS. By highlighting the mechanisms involved in physiological and noncancerous pathological cellular crosstalk, we provide hints that may inspire additional translational studies on cancer–nerve interplay.

The Therapeutic Potential of Exosomes in Soft Tissue Repair and Regeneration

Soft tissue defects are common following trauma and tumor extirpation. These injuries can result in poor functional recovery and lead to a diminished quality of life. The healing of skin and muscle is a complex process that, at present, leads to incomplete recovery and scarring. Regenerative medicine may offer the opportunity to improve the healing process and functional outcomes. Barriers to regenerative strategies have included cost, regulatory hurdles, and the need for cell-based therapies. In recent years, exosomes, or extracellular vesicles, have gained tremendous attention in the field of soft tissue repair and regeneration. These nanosized extracellular particles (30-140 nm) can break the cellular boundaries, as well as facilitate intracellular signal delivery in various regenerative physiologic and pathologic processes. Existing studies have established the potential of exosomes in regenerating tendons, skeletal muscles, and peripheral nerves through different mechanisms, including promoting myogenesis, increasing tenocyte differentiation and enhancing neurite outgrowth, and the proliferation of Schwann cells. These exosomes can be stored for immediate use in the operating room, and can be produced cost efficiently. In this article, we critically review the current advances of exosomes in soft tissue (tendons, skeletal muscles, and peripheral nerves) healing. Additionally, new directions for clinical applications in the future will be discussed.

Regulating the production and biological function of small extracellular vesicles: current strategies, applications and prospects

Numerous studies have confirmed the great application potentials of small extracellular vesicles (sEVs) in biological medical field, especially in tissue repair and regeneration. However, the production capability of sEVs by noncancerous cells is very limited, while their dosage requirements in disease treatments are usually very high. Meanwhile, as cell aging, the sEV production capability of cells decreases and the biological function of sEVs changes accordingly. In addition, for special applications, sEVs carrying desired bioactive substances should be designed to perform their expected biological function. Therefore, improving the production of sEVs and precisely regulating their biological function are of great significance for promoting the clinical applications of sEVs. In this review, some of the current classic strategies in affecting the cellular behaviors of donor cells and subsequently regulating the production and biological function of their sEVs are summarized, including gene engineering methods, stress-inducing conditions, chemical regulators, physical methods, and biomaterial stimulations. Through applying these strategies, increased yield of sEVs with required biological function can be obtained for disease treatment and tissue repair, such as bone regeneration, wound healing, nerve function recovery and cancer treatment, which could not only reduce the harvest cost of sEV but promote the practical applications of sEVs in clinic.

Effects of androgen on extracellular vesicles from endothelial cells in rat penile corpus cavernosum

BACKGROUND

The explicit mechanism of erectile dysfunction caused by low androgen status is unknown. It was reported that eNOS was expressed in extracellular vesicles (EVs). Androgen may regulate erectile function by affect the release of EVs from endothelial cells.

OBJECTIVES

To investigate whether androgen affects the production of EVs and nitric oxide (NO) in endothelial cells of rat penile corpus cavernosum.

MATERIALS AND METHODS

Endothelial cells of rat penile corpus cavernosum were isolated and purified from 6-week-old healthy male Sprague Dawley (SD) rats. Endothelial cells were treated with different concentrations of dihydrotestosterone (DHT) in a cell culture medium as follows: no-androgen group (NA group, DHT 0 nmol/L), very-low androgen group (VLA group, DHT 0.1 nmol/L), low androgen group (LA group, DHT 1 nmol/L), and physiological concentrations androgen group (PA group, DHT 10 nmol/L). After 24 h, EVs of supernatant in each group were isolated and identified. The content of EVs and NO in the supernatant and the expression of CD9, CD63, TSG101, and eNOS in EVs were detected.

RESULTS

Positive expression of CD9, CD63, TSG101, and eNOS was found in isolated EVs. The concentration of EVs was lower in the NA group compared with other groups (p < 0.01). The expression of eNOS and the concentration of NO was lower in the NA group than that in other groups (p < 0.05); it was lower in the VLA group than that in the LA group (p < 0.05) and lower in LA group than that in PA group (p < 0.05). When the concentration of DHT in endothelial cell culture medium ranged from 0 to 10 nmol/L, the concentration of DHT was positively correlated with the content of EVs and NO.

CONCLUSION

Decrease in eNOS-expressing EVs is one mechanism of NO reduction in endothelial cells of rat corpus cavernosum caused by low androgen levels.