Introduction: Stem cell therapies represent a promising new frontier for the treatment of refractory diabetic erectile dysfunction (DED). The use of stem cell-derived extracellular vesicles (EVs) is a novel strategy for cellfree stem cell therapy. We have reported that urine-derived stem cells (USCs) can improve DED; however, the therapeutic effects of EVs secreted by USCs (USC-EVs) remain unknown. Aim: To determine the therapeutic effects of USC-EVs on DED in a rat model. Methods: USC-EVs were isolated from conditioned medium by ultracentrifugation. DED was induced in male SpragueeDawley rats via an intraperitoneal injection of streptozotocin. Sixteen DED rats were divided into phosphate-buffered saline (PBS) and USC-EV groups. Eight normal rats served as the normal control group. PBS or USC-EVs were transplanted into the corpora cavernosa in the corresponding groups. Main Outcome Measure: Intracavernosal pressure (ICP), mean arterial pressure (MAP), expression of endothelial markers (CD31), endothelial nitric oxide synthase (eNOS), phospho-eNOS, and neural nitric oxide synthase (nNOS) were assessed in each group. Masson's trichrome staining was used to determine the collagen deposition and ratio of smooth muscle cells to collagen. The microRNA (miRNA) cargo of USC-EVs was characterized by high-throughput RNA sequencing. Results: Recovery of erectile function was observed in the USC-EV group, as represented by improved ICP and ICP/MAP ratio. CD31, eNOS, phospho-eNOS, and nNOS expression in the penis was significantly improved in the USC-EV group. In addition, the ratio of smooth muscle to collagen was significantly increased in the USC-EV group. RNA sequencing revealed that USC-EVs were enriched for distinct classes of miRNA (miR-21-5p, let-7 family, miR-10 family, miR-30 family, and miR-148a-3p) that promote angiogenesis. Conclusion: USC-EV transplantation can ameliorate DED in rats. Its mechanism may involve the delivery of proangiogenic miRNA. Ouyang B, Xie Y, Zhang C, et al. Extracellular Vesicles From Human Urine-Derived Stem Cells Ameliorate Erectile Dysfunction in a Diabetic Rat Model by Delivering Proangiogenic MicroRNA. Sex Med 2019;7:241e250.

Male late-onset hypogonadism is an age-related disease, the core mechanism of which is dysfunction of senescent Leydig cells. Recent studies have shown that elimination of senescent cells can restore proper homeostasis to aging tissue. In the present study, we found that the fork head box O (FOXO) transcription factor FOXO4 was specially expressed in human Leydig cells and that its translocation to the nucleus in the elderly was related to decreased testosterone synthesis. Using hydrogen peroxide-induced senescent TM3 Leydig cells as an in vitro model, we observed that FOXO4 maintains the viability of senescent Leydig cells and suppresses their apoptosis. By disrupting the FOXO4-p53 interaction, FOXO4-DRI, a specific FOXO4 blocker, selectively induced p53 nuclear exclusion and apoptosis in senescent Leydig cells. In naturally aged mice, FOXO4-DRI improved the testicular microenvironment and alleviated age-related testosterone secretion insufficiency. These findings reveal the therapeutic potential of FOXO4-DRI for the treatment of male late-onset hypogonadism.

STUDY QUESTION Whether the testis-specific extracellular vesicle (EV) long noncoding RNAs (lncRNAs) in seminal plasma could be utilized to predict the presence of testicular spermatozoa in nonobstructive azoospermia (NOA) patients? SUMMARY ANSWER Our findings indicate that the panel based on seminal plasma EV lncRNAs was a sensitive and specific method in predicting the presence of testicular spermatozoa and may improve clinical decision-making of NOA. WHAT IS KNOWN ALREADY The adoption of sperm retrieval techniques, especially microdissection testicular sperm extraction (mTESE), in combination with ICSI has revolutionized treatment for NOA. However, there are no precise and noninvasive methods for predicting whether there are testicular spermatozoa in NOA patients before mTESE. STUDY DESIGN, SIZE, DURATION RNA sequencing was performed on seminal plasma EVs from 6 normozoospermic men who underwent IVF due to female factor and 5 idiopathic NOA patients who failed to obtain testicular spermatozoa by mTESE and were diagnosed as having Sertoli cell-only syndrome by postoperative pathology. A biomarker panel of lncRNAs was constructed and verified in 96 NOA patients who underwent mTESE. Decision-making process was established based on the panel in seminal plasma EVs from 45 normozoospermia samples, 43 oligozoospermia samples, 62 cryptozoospermia samples, 96 NOA samples. PARTICIPANTS/MATERIALS, SETTING, METHODS RNA sequencing was done to examine altered profiles of EV lncRNAs in seminal plasma. Furthermore, a panel consisting of EV lncRNAs was established and evaluated in training set and validation sets. MAIN RESULTS AND THE ROLE OF CHANCE A panel consisting of nine differentially expressed testis-specific lncRNAs, including LOC100505685, SPATA42, CCDC37-DT, GABRG3-AS1, LOC440934, LOC101929088 (XR_927561.2), LOC101929088 (XR_001745218.1), LINC00343 and LINC00301, was established in the training set and the AUC was 0.986. Furthermore, the AUC in the validation set was 0.960. Importantly, the panel had a unique advantage when compared with models based on serum hormones from the same group of NOA cases (AUC, 0.970 vs 0.723; 0.959 vs 0.687, respectively). According to the panel of lncRNAs, a decision-making process was established, that is when the score of an NOA case exceeds 0.532, sperm retrieval surgery may be recommended. LIMITATIONS, REASONS FOR CAUTION In the future, the sample size needs to be further expanded. Meanwhile, the regulatory functions and mechanism of lncRNAs in spermatogenesis also need to be elucidated. WIDER IMPLICATIONS OF THE FINDINGS When the score of our panel is below 0.532, subjecting the NOA patients to ineffective surgical interventions may not be recommended due to poor sperm retrieval rate. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the National Natural Science Foundation of China (81871110, 81971314 and 81971759); the Guangdong Special Support Plan-Science and Technology Innovation Youth Top Talents Project (2016TQ03R444); the Science and Technology Planning Project of Guangdong Province (2016B030230001 and 201707010394); the Key Scientific and Technological Program of Guangzhou City (201604020189); the Pearl River S&T Nova Program of Guangzhou (201806010089); the Transformation of Scientific and Technological Achievements Project of Sun Yat-sen University (80000-18843235) and the Youth Teacher Training Project of Sun Yat-sen University (17ykpy68 and 18ykpy09). There are no competing interests related to this study. TRIAL REGISTRATION NUMBER N/A.

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Aims. Cavernosal endothelial dysfunction is one of the factors in developing diabetic erectile dysfunction (DED), but the mechanism of cavernosal endothelial dysfunction is unclear. The present study is aimed at determining the contribution of autophagy in cavernosal endothelial dysfunction of DED rats and explaining the therapeutic effect of urine-derived stem cells (USCs). Methods. After rat corpus cavernosal vascular endothelial cells (CCECs) were isolated and cultured in vitro, CCECs were treated with advanced glycation end products (AGEs) to mimic the diabetic situation. Autophagy flux, proliferation, and apoptosis of CCECs were determined by mRFP-GFP-LC3 adenovirus infection combined with fluorescence observation and western blot analysis. USCs were isolated from the urine of six healthy male donors, and coculture systems of USCs and CCECs were developed to assess the protective effect of USCs for CCECs in vitro. The contribution of autophagy to the cellular damage in CCECs was evaluated by the autophagic inhibitor, 3-methyladenine (3-MA). Then, DED rats were induced by streptozotocin (50 mg/kg) and screened by apomorphine test (100 μg/kg). In DED rats, USCs or PBS as vehicle was administrated by intracavernous injection (n=15 per group), and another 15 normal rats served as normal controls. Four weeks after injection, erectile function was evaluated by measuring the intracavernosal pressure (ICP) and mean arterial pressure (MAP). Cavernosal endothelial function and autophagic activity were examined by western blot, immunofluorescence, and transmission electron microscopy. Results. In vitro, AGE-treated CCECs displayed fewer LC3 puncta formation and expressed less LC3-II, Beclin1, and PCNA but expressed more p62 and cleaved-caspase3 than controls (p<0.05). Coculture of USCs with CCECs demonstrated that USCs were able to protect CCECs from AGE-induced autophagic dysfunction and cellular damage, which could be abolished by 3-MA (p<0.05). DED rats showed lower ratio of ICP/MAP, reduced expression of endothelial markers, and fewer autophagic vacuoles in the cavernosal endothelium when compared with normal rats (p<0.05). Intracavernous injection of USCs improved erectile function and cavernosal endothelial function of DED rats (p<0.05). Most importantly, our data showed that the repaired erectile function and cavernosal endothelial function were the result of restored autophagic activity of the cavernosal endothelium in DED rats (p<0.05). Conclusions. Impaired autophagy is involved in the cavernosal endothelial dysfunction and erectile dysfunction of DED rats. Intracavernous injection of USCs upregulates autophagic activity in the cavernosal endothelium, contributing to ameliorating cavernosal endothelial dysfunction and finally improving the erectile dysfunction induced by diabetes.