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It has been hypothesized that transforming growth factor- β1 (TGF- β1) signalling is involved in erectile dysfunction (ED). This study was undertaken to elucidate in detail whether expression of TGF- β1 and its type II receptor is clinically related to various causes of ED. Fifty-four patients with ED and 24 potent men were the subjects of this study. After multidisciplinary work-up, the ED was classified as psychogenic ( n = 6), neurogenic ( n = 15), or vasculogenic ( n = 33). In every subject, percutaneous cavernous biopsy was performed using a Biopty gun. Masson's trichrome staining was used to quantitate collagen fibres and immunohistochemical staining to evaluate both TGF- β1 and its type II receptor by scoring the intensity of immunoreactivity (score 0–6). Collagen fibres were significantly more abundant in men with vasculogenic ED (72.7 ± 17.7%) than in control subjects (43.3 ± 11.2%) or those with psychogenic (45.0 ± 12.2%) or neurogenic (51.3 ± 20.3%) ED ( p < 0.01). Expression of TGF- β1 was significantly greater in vasculogenic ED (4.3 ± 1.3) than in the control subjects (2.4 ± 0.9) or psychogenic ED (2.0 ± 0.6) groups ( p < 0.01). Type II receptor expression was also significantly increased in vasculogenic ED (3.9 ± 1.3) compared with control (2.2 ± 0.7) and psychogenic (2.2 ± 0.8) or neurogenic (2.6 ± 1.3) ED ( p < 0.01). Of the ED groups, both the hyperlipidaemia and the atherosclerosis patients showed significantly more fibrosis than those without the condition ( p < 0.05). The abundance of collagen fibres correlated well with both TGF- β1 expression ( γ = 0.81; p < 0.001) and receptor II expression ( γ = 0.83; p < 0.001). These results suggest that TGF- β1 and its receptor II pathway are involved in cavernous fibrosis and ED in man. Patients with vascular risk factors such as hyperlipidaemia and atherosclerosis are liable to ED by activation of this pathway. [ABSTRACT FROM AUTHOR]

Background: The odds of erectile dysfunction are three times more prevalent in diabetes. Severe peripheral vascular and neural damage in diabetic patients responds poorly to phosphodiesterase‐5 (PDE5) inhibitors. However, bone morphogenetic protein 2 is known to be involved in angiogenesis. Objectives: To assess the efficacy of bone morphogenetic protein 2 in stimulating angiogenesis and augmenting nerve regeneration in a mouse model of diabetic‐induced erectile dysfunction. Materials and methods: The induction of diabetes mellitus was performed by streptozotocin (50 mg/kg daily) administered intraperitoneally for 5 successive days to male C57BL/6 mice that were 8 weeks old. Eight weeks post‐inductions, animals were allocated to one of five groups: a control group, a streptozotocin‐induced diabetic mouse group receiving two intracavernous 20 μL phosphate‐buffered saline injections, or one of three bone morphogenetic protein 2 groups administered two injections of bone morphogenetic protein 2 protein (1, 5, or 10 μg) diluted in 20 μL of phosphate‐buffered saline within a 3‐day interval between the first and second injections. The erectile functions were assessed 2 weeks after phosphate‐buffered saline or bone morphogenetic protein 2 protein injections by recording the intracavernous pressure through cavernous nerve electrical stimulation. Angiogenic activities and nerve regenerating effects of bone morphogenetic protein 2 were determined in penile tissues, aorta, vena cava, the main pelvic ganglions, the dorsal roots, and from the primary cultured mouse cavernous endothelial cells. Moreover, fibrosis‐related factor protein expressions were evaluated by western blotting. Results: Erectile function recovery to 81% of the control value in diabetic mice was found with intracavernous bone morphogenetic protein 2 injection (5 μg/20 μL). Pericytes and endothelial cells were extensively restored. It was confirmed that angiogenesis was promoted in the corpus cavernosum of diabetic mice treated with bone morphogenetic protein 2 through increased ex vivo sprouting of aortic rings, vena cava and penile tissues, and migration and tube formation of mouse cavernous endothelial cells. Bone morphogenetic protein 2 protein enhanced cell proliferation and reduced apoptosis in mouse cavernous endothelial cells and penile tissues, and promoted neurite outgrowth in major pelvic ganglia and dorsal root ganglia under high‐glucose conditions. Furthermore, bone morphogenetic protein 2 suppressed fibrosis by reducing mouse cavernous endothelial cell fibronectin, collagen 1, and collagen 4 levels under high‐glucose conditions. Conclusion: Bone morphogenetic protein 2 modulates neurovascular regeneration and inhibits fibrosis to revive the mouse erection function in diabetic conditions. Our findings propose that the bone morphogenetic protein 2 protein represents a novel and promising approach to treating diabetes‐related erectile dysfunction. [ABSTRACT FROM AUTHOR]

Severe vascular and nerve damage from diabetes is a leading cause of erectile dysfunction (ED) and poor response to oral phosphodiesterase 5 inhibitors. Argonaute 2 (Ago2), a catalytic engine in mammalian RNA interference, is involved in neurovascular regeneration under inflammatory conditions. In the present study, we report that Ago2 administration can effectively improve penile erection by enhancing cavernous endothelial cell angiogenesis and survival under diabetic conditions. We found that although Ago2 is highly expressed around blood vessels and nerves, it is significantly reduced in the penis tissue of diabetic mice. Exogenous administration of the Ago2 protein restored erectile function in diabetic mice by reducing reactive oxygen species production-signaling pathways (inducing eNOS Ser1177/NF-κB Ser536 signaling) and improving cavernous endothelial angiogenesis, migration, and cell survival. Our study provides new evidence that Ago2 mediation may be a promising therapeutic strategy and a new approach for diabetic ED treatment. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess the potential of oriental melon (Cucumis melo L. var. makuwa Makino) seeds for the management of hyperglycemia linked to type 2 diabetes. The inhibitory effects of the hexane extracts of roasted melon seed on α-glucosidase and α-amylase were examined under different roasting temperatures, and compared with those of the unroasted seeds. The highest hypoglycemic activity was exerted by the seed roasted at 250°C for 90min with an inhibition value of 87.7% and 52.3% against α-amylase and α-glucosidase, respectively. The α-glucosidase and α-amylase inhibitory effects were strongly correlated with the levels of triacylglyceride esterified with linoleic acid (trilinolein). These results suggest that oriental melon seed extracts contain TAG and unsaturated fatty acids, which are potent inhibitors of α-glucosidase and α-amylase Hence it is clear that oriental melon seeds, which at present are considered as agricultural waste, may usefully be extracted and added to foods. [Copyright &y& Elsevier]

Neovascularization of the erectile tissue emerges as a beneficial curative approach to treat erectile dysfunction (ED). Here we for the first time report the unexpected role of vasohibin-1 (VASH1), mainly known as an anti-angiogenic factor, in restoring erectile function in diabetic mice. A diabetic patient has lower cavernous VASH1 expression than in the potent man. VASH1 was mainly expressed in endothelial cells. There were significant decreases in cavernous endothelial cell and pericyte contents in VASH1 knockout mice compared with those in wild-type mice, which resulted in impairments in erectile function. Intracavernous injection of VASH1 protein successfully restored erectile function in the diabetic mice (~ 90% of control values). VASH1 protein reinstated endothelial cells, pericytes, and endothelial cell–cell junction proteins and induced phosphorylation of eNOS (Ser1177) in the diabetic mice. The induction of angiogenic factors, such as angiopoietin-1 and vascular endothelial growth factor, is responsible for cavernous angiogenesis and the restoration of erectile function mediated by VASH1. Altogether, these findings suggest that VASH1 is proangiogenic in diabetic penis and is a new potential target for diabetic ED. [ABSTRACT FROM AUTHOR]

Radical prostatectomy for prostate cancer can not only induce cavernous nerve injury (CNI), but also causes cavernous hypoxia and cavernous structural changes, which lead to a poor response to phosphodiesterase 5 inhibitors. To investigate the therapeutic effect of oral administration of LM11A-31, a small molecule p75 neurotrophin receptor (p75NTR) ligand and proNGF antagonist, in a mouse model of bilateral CNI, which mimics nerve injury–induced erectile dysfunction after radical prostatectomy. 8-week-old male C57BL/6 mice were divided into sham operation and CNI groups. Each group was divided into 2 subgroups: phosphate-buffered saline and LM11A-31 (50 mg/kg/day) being administered once daily starting 3 days before CNI via oral gavage. 2 weeks after CNI, we measured erectile function by electrical stimulation of the bilateral cavernous nerve. The penis was harvested for histologic examination and Western blot analysis. The major pelvic ganglia was harvested and cultured for assays of ex vivo neurite outgrowth. Intracavernous pressure, neurovascular regeneration in the penis, in vivo or ex vivo functional evaluation, and cell survival signaling were measured. Erectile function was decreased in the CNI group (44% of the sham operation group), while administration of LM11A-31 led to a significant improvement of erectile function (70% of the sham operation group) in association with increased neurovascular content, including cavernous endothelial cells, pericytes, and neuronal processes. Immunohistochemical and Western blot analyses showed significantly increased p75NTR expression in the dorsal nerve of CNI mice, which was attenuated by LM11A-31 treatment. Protein expression of active PI3K, AKT, and endothelial nitric oxide synthase was increased, and cell death and c-Jun N-terminal kinase signaling was significantly attenuated after LM11A-31 treatment. Furthermore, LM11A-31 promoted neurite sprouting in cultured major pelvic ganglia after lipopolysaccharide exposure. LM11A-31 may be used as a strategy to treat erectile dysfunction after radical prostatectomy or in men with neurovascular diseases. Unlike biological therapeutics, such as proteins, gene therapies, or stem cells, the clinical application of LM11A-31 would likely be relatively less complex and low cost. Our study has some limitations. Future studies will assess the optimal dosing and duration of the compound. Given its plasma half-life of approximately 1 hour, it is possible that dosing more than once per day will provide added efficacy. Specific inhibition of the proNGF-p75NTR degenerative signaling via oral administration of LM11A-31 represents a novel therapeutic strategy for erectile dysfunction induced by nerve injury. Yin GN, Ock J, Limanjaya A, et al. Oral Administration of the p75 Neurotrophin Receptor Modulator, LM11A-31, Improves Erectile Function in a Mouse Model of Cavernous Nerve Injury. J Sex Med 2021;18:17–28. [ABSTRACT FROM AUTHOR]

Extracellular vesicle (EV)–mimetic nanovesicles (NVs) from embryonic stem cells have been observed to stimulate neurovascular regeneration in the streptozotocin-induced diabetic mouse. Pericytes play important roles in maintaining penile erection, yet no previous studies have explored the effects of pericyte-derived NVs (PC-NVs) in neurovascular regeneration in the context of erectile dysfunction. To investigate the potential effect of PC-NVs in neurovascular regeneration. PC-NVs were isolated from mouse cavernous pericytes, and neurovascular regeneration was evaluated in an in vitro study. Twelve-week-old C57BL/6J mice were used to prepare cavernous nerve injury model. Erectile function evaluation, histologic examination of the penis, and Western blots were assessed 2 weeks after model creation and PC-NVs treatment. The main outcomes of this study are PC-NVs characterization, intracavernous pressure, neurovascular regeneration in the penis, and in vitro functional evaluation. The PC-NVs were extracted and characterized by cryotransmission electron microscopy and EV-positive (Alix, TSG101, CD81) and EV-negative (GM130) markers. In the in vivo studies, PC-NVs successfully improved erectile function in cavernous nerve injury mice (∼82% of control values). Immunofluorescence staining showed significant increases in pericytes, endothelial cell, and neuronal contents. In the in vitro studies, PC-NVs significantly increased mouse cavernous endothelial cells tube formation, Schwann cell migration, and dorsal root ganglion and major pelvic ganglion neurite sprouting. Finally, Western blot analysis revealed that PC-NVs upregulated cell survival signaling (Akt and eNOS) and induced the expression of neurotrophic factors (brain-derived neurotrophic factor, neurotrophin-3, and nerve growth factor). PC-NVs may be used as a strategy to treat erectile dysfunction after radical prostatectomy or in men with neurovascular diseases. We evaluated the effect of PC-NVs in vitro and in a mouse nerve injury model, cavernous nerve injury. Additional studies are necessary to determine the detailed mechanisms of neurovascular improvement. Further study is needed to test whether PC-NVs are also effective when given weeks or months after nerve injury. PC-NVs significantly improved erectile function by enhancing neurovascular regeneration. Local treatment with PC-NVs may represent a promising therapeutic strategy for the treatment of neurovascular diseases. Yin GN, Park S-H, Ock J, et al. Pericyte-Derived Extracellular Vesicle–Mimetic Nanovesicles Restore Erectile Function by Enhancing Neurovascular Regeneration in a Mouse Model of Cavernous Nerve Injury. J Sex Med 2020;17:2118–2128. [ABSTRACT FROM AUTHOR]

Introduction Diabetic erectile dysfunction is a disease mostly of vascular origin and men with diabetic erectile dysfunction respond poorly to oral phosphodiesterase-5 inhibitors. Hepatocyte growth factor (HGF) is a pleiotropic factor that plays an essential role in the regulation of cell proliferation, survival, and angiogenesis. Aim To determine the effectiveness of recombinant human (rh)-HGF in restoring erectile function in diabetic mice. Methods Four groups of mice were used: control non-diabetic mice and streptozotocin-induced diabetic mice receiving two successive intracavernous injections of phosphate buffered saline (days −3 and 0), a single intracavernous injection of rh-HGF (day 0), or two successive intracavernous injections of rh-HGF (days −3 and 0). We also examined the effect of rh-HGF in primary cultured mouse cavernous endothelial cells and in major pelvic ganglion culture in vitro, which was incubated under a normal-glucose (5 mmol/L) or a high-glucose (30 mmol/L) condition. Main Outcome Measures Two weeks after treatment, we measured erectile function by electrical stimulation of the cavernous nerve and the penis was harvested for histologic studies. Results Repeated intracavernous injections of rh-HGF protein induced significant restoration of erectile function in diabetic mice (89–100% of control values), whereas a single intracavernous injection of rh-HGF protein elicited modest improvement. Rh-HGF significantly induced phosphorylation of its receptor c-Met, increased the content of endothelial cells and smooth muscle cells, and decreased the generation of reactive oxygen species (superoxide anion and peroxynitrite) and extravasation of oxidized low-density lipoprotein in diabetic mice. Under the high-glucose condition, rh-HGF protein also promoted tube formation in mouse cavernous endothelial cells and enhanced neurite sprouting in major pelvic ganglion culture in vitro. Conclusion The dual angiogenic and neurotrophic effects of HGF could open a new avenue through which diabetic erectile dysfunction can be treated. [ABSTRACT FROM AUTHOR]

Objectives To investigate bacterial infection in the seminal vesicles by bacteriological examination and radionuclide imaging in men with chronic prostatitis. Methods The study included 50 patients with chronic prostatitis who showed hot uptake in seminal vesicles on Tc-99 m ciprofloxacin imaging and eight patients who did not show hot uptake. The evaluation included the National Institutes of Health Chronic Prostatitis Symptom Index and four-glass test. In all participants, transperineal aspiration of seminal vesicle fluid under the guidance of transrectal ultrasonography and bacteriological examination was carried out. Results Of the 50 patients who showed hot uptake in the seminal vesicles on the isotope study, microorganisms were isolated from the seminal vesicle fluid in 17 patients (positive predictive value, 34%). The most common causative organisms were Escherichia coli in 13 patients (26%), followed by coagulase-negative Staphylococcus species in two patients (4%), Enterococcus faecalis in one patient (2%) and Chlamydia trachomatis in one patient (2%). No microorganisms were isolated in the eight patients who did not show hot uptake in the seminal vesicles (negative predictive value, 100%). However, there were no significant differences in National Institutes of Health Chronic Prostatitis Symptom Index total scores and subscores between the study groups. Conclusions Chronic bacterial seminal vesiculitis might simultaneously affect a considerable portion of patients with chronic prostatitis, although the clinical implication of the disease remains to be further investigated. [ABSTRACT FROM AUTHOR]

Objectives To examine the therapeutic effect of adenovirus encoding histone deacetylase 2 ( HDAC2) small hairpin RNA ( Ad-HDAC2 shRNA) in a rat model of Peyronie's disease ( PD) and to determine the mechanisms by which HDAC2 knockdown ameliorates fibrotic responses in primary fibroblasts derived from human PD plaque. Materials and Methods Rats were distributed into four groups ( n = 6 per group): age-matched controls without treatment; rats in which PD has been induced ( PD rats) without treatment; PD rats receiving a single injection of control adenovirus encoding scrambled small hairpin RNA (Ad-shRNA) (day 15; 1 × 108 pfu/0.1 mL phosphate-buffered saline [ PBS]); and PD rats receiving a single injection of Ad-HDAC2 shRNA (day 15; 1 × 108 pfu/0.1 mL PBS) into the lesion. PD-like plaque was induced by repeated intratunical injections of 100 μL each of human fibrin and thrombin solutions on days 0 and 5. On day 30, the penis was harvested for histological examination. Fibroblasts isolated from human PD plaque were pretreated with HDAC2 small interfering (si) RNA (100 pmoL) and then stimulated with transforming growth factor ( TGF)-β1 (10 ng/mL) to determine hydroxyproline levels, procollagen mRNA, apoptosis and protein expression of poly( ADP-ribose) polymerase 1 ( PARP1) and cyclin D1. Results We observed that Ad-HDAC2 shRNA decreased inflammatory cell infiltration, reduced transnuclear expression of phospho- Smad3 and regressed fibrotic plaque of the tunica albuginea in PD rats in vivo. siRNA-mediated silencing of HDAC2 significantly decreased the TGF-β1-induced transdifferentiation of fibroblasts into myofibroblasts and collagen production, and induced apoptosis by downregulating the expression of PARP1, and decreased the expression of cyclin D1 (a positive cell-cycle regulator) in primary cultured fibroblasts derived from human PD plaque in vitro. Conclusion Specific inhibition of HDAC2 with RNA interference may represent a novel targeted therapy for PD. [ABSTRACT FROM AUTHOR]

Introduction Erectile dysfunction ( ED) is a major complication of radical prostatectomy. Men with radical prostatectomy-induced ED respond less positively to oral phosphodiesterase-5 inhibitors. Aim The study aims to examine whether and how stromal vascular fraction ( SVF) restores erectile function in mice with cavernous nerve injury ( CNI). Methods Twelve-week-old male C57BL/6J mice were used and the animals were distributed into five groups: sham operation group and CNI group receiving a single intracavernous injection of phosphate-buffered saline ( PBS) or SVF (1 × 104, 1 × 105, or 3 × 105 cells/20 μL, respectively). SVF was isolated from epididymal adipose tissues of green fluorescence protein transgenic mice. Main Outcome Measures Two weeks after injection, erectile function was measured by cavernous nerve stimulation. The penis was stained with antibodies to platelet/endothelial cell adhesion molecule-1, phosphohistone H3, and phosphorylated endothelial nitric oxide synthase (phospho- eNOS). We also performed Western blot for angiopoietin-1 ( Ang-1), vascular endothelial growth factor- A, hepatocyte growth factor, phospho- eNOS, and eNOS in the corpus cavernosum tissue. Results Local delivery of SVF restored erectile function in a dose-dependent manner in CNI mice. The highest erectile response was noted at a dose of 3 × 105 cells, for which the response was comparable with that in the sham operation group. Local delivery of SVF significantly increased the expression of angiogenic factor proteins and induced cavernous endothelial cell proliferation and eNOS phosphorylation compared with that in the PBS-treated CNI group. SVF-induced promotion of cavernous angiogenesis and erectile function was diminished in the presence of soluble antibody to Tie2, a receptor tyrosine kinase of Ang-1. Conclusion Secretion of angiogenic factors from SVF is an important mechanism by which SVF induces cavernous endothelial regeneration and restores erectile function. These findings suggest that cavernous endothelial regeneration by using SVF may represent a promising treatment strategy for radical prostatectomy-induced ED. Song K-M, Jin H-R, Park J-M, Choi MJ, Kwon M-H, Kwon K-D, Batbold D, Yin GN, Kim WJ, Koh GY, Ryu J-K, and Suh J-K. Intracavernous delivery of stromal vascular fraction restores erectile function through production of angiogenic factors in a mouse model of cavernous nerve injury. J Sex Med 2014;11:1962-1973. [ABSTRACT FROM AUTHOR]

Introduction Recently, much attention has focused on stem cell therapy; bone marrow-derived stem cells ( BMSCs) are one of the most studied mesenchymal stem cells used in the field of erectile dysfunction ( ED). However, a major limitation for the clinical application of stem cell therapy is the heterogeneous nature of the isolated cells, which may cause different treatment outcomes. Aim We investigated the effectiveness of mouse clonal BMSCs obtained from a single colony by using subfractionation culturing method ( SCM) for erectile function in a mouse model of cavernous nerve injury ( CNI). Methods Twelve-week-old C57 BL/6 J mice were divided into four groups: sham operation group, bilateral CNI group receiving a single intracavernous ( IC) injection of phosphate-buffered saline (20 μL) or clonal BMSCs (3 × 105 cells/20 μL), and receiving a single intraperitoneal ( IP) injection of clonal BMSCs (3 × 105 cells/20 μL). Main Outcome Measures The clonal BMSC line was analyzed for cell-surface epitopes by using fluorescence-activated cell sorting and for differentiation potential. Two weeks after CNI and treatment, erectile function was measured by electrically stimulating the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis. Results Clonal BMSCs expressed cell surface markers for mesenchymal stem cells and were capable of differentiating into several lineages, including adipogenic, osteogenic, and chondrogenic cells. Both IC and IP injections of clonal BMSCs significantly restored cavernous endothelial and smooth muscle content, and penile nNOS and neurofilament content in CNI mice. IC injection of clonal BMSCs induced significant recovery of erectile function, which reached 90-100% of the sham control values, whereas IP injection of clonal BMSCs partially restored erectile function. Conclusion We established a homogeneous population of mouse clonal BMSCs using SCM; clonal BMSCs successfully restored erectile function in CNI mice. The homogeneous nature of clonal mesenchymal stem cells may allow their clinical applications. Ryu J-K, Kim D-H, Song KM, Yi TG, Suh J-K, and Song SU. Intracavernous delivery of clonal mesenchymal stem cells restores erectile function in a mouse model of cavernous nerve injury. J Sex Med 2014;11:411-423. [ABSTRACT FROM AUTHOR]

Introduction Men with erectile dysfunction ( ED) respond poorly to oral phosphodiesterase-5 inhibitors following radical prostatectomy. Recent studies have reported that up-regulation of transforming growth factor-β1 ( TGF-β1) and activation of the Smad signaling pathway play important roles in cavernous fibrosis and in the deterioration of erectile function in a mouse model of cavernous nerve injury ( CNI) and in patients with spinal cord injury. The mothers against decapentaplegic homolog 7 ( Smad7) is known to inhibit the phosphorylation of Smad2 and Smad3. Aim To investigate the effectiveness of adenoviruses encoding Smad7 gene ( Ad- Smad7) on erectile function in a mouse model of CNI. Methods Twelve-week-old C57 BL/6 J mice were used and distributed into 7 groups: sham operation group, untreated CNI group, and CNI groups receiving a single intracavernous injection of adenovirus encoding Lac Z (1 × 108 virus particles [vp]/20 μL) or adenovirus encoding Smad7 ( Ad- Smad7; 1 × 107, 1 × 108, 2 × 108, or 1 × 109 vp/20 μL). Main Outcome Measures Two weeks after bilateral cavernous nerve crushing and treatment, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis. Results The highest erectile response was noted in CNI mice treated with Ad- Smad7 at a dose of 1 × 108 vp, which reached up to 82-85% of sham control values. Local delivery of Ad- Smad7 significantly decreased endothelial cell apoptosis and the production of extracellular matrix proteins, including plasminogen activator inhibitor-1, fibronectin, collagen I, and collagen IV, and induced endothelial nitric oxide synthase phosphorylation in the corpus cavernosum tissue of CNI mice. Conclusion The adenovirus-mediated gene transfer of Smad7 successfully restored erectile function by enhancing endothelial cell function and through antifibrotic effects. These findings suggest that inhibition of the TGF-β signaling pathway by use of Smad7 may represent a promising therapeutic strategy for ED induced by radical prostatectomy. Song KM, Chung J-S, Choi MJ, Jin H-R, Yin GN, Kwon M-H, Park J-M, Kim WJ, Lee S-J, Kim S-J, Ryu J-K, and Suh J-K. Effectiveness of intracavernous delivery of adenovirus encoding Smad7 gene on erectile function in a mouse model of cavernous nerve injury. J Sex Med 2014;11:51-63. [ABSTRACT FROM AUTHOR]

Introduction Much attention has recently been focused on therapeutic angiogenesis as a treatment for erectile dysfunction ( ED). The apelin and apelin receptor ( APJ) system is known to cause endothelium-dependent vasodilatation and to be involved in angiogenesis. Aim To examine the differential expression of apelin and APJ in animal models of vasculogenic ED and to determine whether and how enhancement of apelin- APJ signaling restores erectile function in hypercholesterolemic mice. Methods Acute cavernous ischemia was induced in C57 BL/6 J mice by bilateral occlusion of internal iliac arteries, and chronic vasculogenic ED was induced by feeding a high-cholesterol diet or by intraperitoneal injection of streptozotocin. Main Outcome Measures Messenger RNA ( mRNA) levels of apelin and APJ were determined in cavernous tissue of each vasculogenic ED model by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR). We evaluated erectile function by electrical stimulation of the cavernous nerve in hypercholesterolemic mice 1, 3, 7, and 14 days after a single intracavernous injection of apelin protein (5 μg/20 μL). The penis was harvested for histologic examinations and Western blot analysis. Results The cavernous mRNA expression of apelin and APJ was up-regulated in acute ischemia model and down-regulated in chronic vasculogenic ED models. A significant restoration of erectile function was noted 1 day after injection of apelin protein into the penis of hypercholesterolemic mice; however, erectile function returned to baseline values thereafter. The beneficial effects of apelin on erectile function resulted mainly from an activation of endothelial nitric oxide synthase and increase in nitric oxide bioavailability through reduction in reactive oxygen species-mediated endothelial apoptosis rather than through direct endothelial cell proliferation. Conclusion These findings suggest that apelin- APJ signaling is a potential therapeutic target in the treatment of vasculogenic ED. Further studies are needed to develop a potent agonist for APJ and to determine the role of repeated dosing of apelin on long-term recovery of erectile function. Kwon M-H, Tuvshintur B, Kim WJ, Jin H-R, Yin GN, Song K-M, Choi MJ, Kwon K-D, Batbold D, Ryu J-K, and Suh J-K. Expression of the apelin-APJ pathway and effects on erectile function in a mouse model of vasculogenic erectile dysfunction. J Sex Med 2013;10:2928-2941. [ABSTRACT FROM AUTHOR]

Introduction Erectile dysfunction ( ED) is a highly prevalent complication of diabetes, and the severity of endothelial dysfunction is one of the most important factors in reduced responsiveness to oral phosphodiesterase type 5 inhibitors. Aim To study the effects of human angiopoietin-4 ( Ang-4) protein on erectile function in diabetic mice. Methods Diabetes was induced by intraperitoneal injection of streptozotocin into 8-week-old C57BL/ 6J male mice. At 8 weeks after the induction of diabetes, the animals were divided into four groups: control nondiabetic mice and diabetic mice receiving two successive intracavernous injections of phosphate buffered saline (days −3 and 0), a single intracavernous injection of Ang-4 protein (day 0), or two successive intracavernous injections of Ang-4 protein (days −3 and 0). Main Outcome Measures One week after treatment, we measured erectile function by electrical stimulation of the cavernous nerve. The penis was harvested and stained with hydroethidine or antibodies to Ang-4, platelet/endothelial cell adhesion molecule-1, and phosphorylated endothelial nitric oxide synthase ( eNOS). We also determined the differential expression of Ang-4 in cavernous tissue in the control and diabetic mice. The effect of Ang-4 protein on the phosphorylation of Tie-2, Akt, and eNOS was determined in human umbilical vein endothelial cells ( HUVECs) by Western blot. Results The cavernous expression of Ang-4 was downregulated in diabetic mice; Ang-4 was mainly expressed in endothelial cells. Local delivery of Ang-4 protein significantly increased cavernous endothelial content, induced eNOS phosphorylation, and decreased the generation of superoxide anion and apoptosis in diabetic mice. Ang-4 protein strongly increased the phosphorylation of Tie-2, Akt, and eNOS in HUVECs. Repeated intracavernous injections of Ang-4 induced significant restoration of erectile function in diabetic mice (87% of control values), whereas a single intracavernous injection of Ang-4 protein elicited modest improvement. Conclusions Cavernous endothelial regeneration by use of Ang-4 protein may have potential for the treatment of vascular disease-induced ED, such as diabetic ED. Kwon M-H, Ryu J-K, Kim WJ, Jin H-R, Song K-M, Kwon K-D, Batbold D, Yin GN, Koh GY, and Suh J-K. Effect of intracavernous administration of angiopoietin-4 on erectile function in the streptozotocin-induced diabetic mouse. J Sex Med 2013;10:2912-2927. [ABSTRACT FROM AUTHOR]

Introduction. Radical prostatectomy for prostate cancer can not only induce cavernous nerve injury ( CNI) but also result in structural changes in the cavernous tissues. Nerve injury-induced protein 1, Ninjurin-1 ( Ninj1), is known to be involved in neuroinflammatory processes and to be related to vascular regression during the embryonic period. Aim. The study aims to determine whether and how Ninj1 neutralizing antibody ( Ninj1- Ab) restores erectile function in mice with CNI. Methods. Twelve-week-old C57 BL/6 J mice were used and distributed into four groups: sham operation group and CNI groups receiving a single intracavernous injection of immunoglobulin G ( IgG) control antibody, low-dose Ninj1- Ab (1.0 μg/20 μ L), or high-dose Ninj1- Ab (2.5 μg/20 μ L). Main Outcome Measures. One week after bilateral cavernous nerve crush, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was harvested for histologic examinations and Western blot analysis. Results. The cavernous expression of Ninj1 protein was upregulated up to 7 days after CNI and returned to baseline levels thereafter. Local delivery of Ninj1- Ab significantly increased penile neuronal nitric oxide synthase and neurofilament contents, induced cavernous endothelial proliferation and phosphorylation of Akt and endothelial nitric oxide synthase, and decreased endothelial cell apoptosis in the CNI mice by upregulating angiopoietin-1 and downregulating angiopoietin-2. High-dose Ninj1- Ab induced profound restoration of erectile function in the CNI mice (91% of sham control values), whereas low-dose Ninj1- Ab elicited partial improvement. Conclusion. The dual neurotrophic and angiogenic effects of Ninj1 blockade may provide a good opportunity for treating erectile dysfunction resulting from radical prostatectomy. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction. Men with diabetic erectile dysfunction (ED) often have severe endothelial dysfunction and respond poorly to oral phosphodiesterase-5 inhibitors. Aim. To examine whether and how freshly isolated stromal vascular fraction (SVF) promotes cavernous endothelial regeneration and restores erectile function in diabetic animals. Methods. Eight-week-old C57BL/6J mice were used. Diabetes was induced by intraperitoneal injection of streptozotocin. SVF was isolated from epididymal adipose tissues of green fluorescence protein transgenic mice. At 8 weeks after the induction of diabetes, the animals were divided into six groups: controls, diabetic mice, and diabetic mice treated with a single intracavernous injection of phosphate-buffered saline (PBS) or SVF (1 × 104 cells, 1 × 105 cells, or 2 × 105 cells/20 µL, respectively). Main Outcome Measures. Two weeks later, erectile function was measured by cavernous nerve stimulation. The penis was stained with antibodies to CD31, CD34, phosphohistone H3, phospho-endothelial nitric oxide synthase (eNOS), and vascular endothelial growth factor-A (VEGF-A). We also performed Western blot for phospho-eNOS and eNOS, and determined cyclic guanosine monophosphate (cGMP) concentration in the corpus cavernosum tissue. Results. Significant improvement in erectile function was noted in diabetic mice treated with SVF at concentrations of 1 × 105 and 2 × 105 cells, which reached up to 82% of the control values. Local delivery of SVF significantly increased cavernous endothelial cell proliferation, eNOS phosphorylation, and cGMP expression compared with that in the untreated group and the PBS-treated diabetic group. Intracavernous injection of SVF increased cavernous VEGF-A expression and induced recruitment of CD34(+)CD31(−) progenitor cells. Some SVF underwent differentiation into cavernous endothelial cells. SVF-induced promotion of cavernous angiogenesis and erectile function was abolished in the presence of VEGF-Trap, a soluble VEGF-A neutralizing antibody. Conclusion. The results support the concept of cavernous endothelial regeneration by use of SVF as a curative therapy for diabetic ED. Ryu J-K, Tumurbaatar M, Jin H-R, Kim WJ, Kwon M-H, Piao S, Choi MJ, Yin GN, Song K-M, Kang Y-J, Koh YJ, Koh GY, and Suh J-K. Intracavernous delivery of freshly isolated stromal vascular fraction rescues erectile function by enhancing endothelial regeneration in the streptozotocin-induced diabetic mouse. J Sex Med 2012;9:3051-3065. [ABSTRACT FROM AUTHOR]

Study Type - Therapy (RCT) Level of Evidence 1b What's known on the subject? and What does the study add? Avanafil is a potent selective phosphodiesterase type 5 (PDE5) inhibitor newly developed for treating erectile dysfunction (ED). Preclinical and clinical phase I studies showed that avanafil had enhanced selectivity, faster onset of action and a favourable side-effect profile relative to currently available PDE5 inhibitors. As the result of phase III clinical trial for the efficacy and safety of avanafil treatment (100 and 200 mg), taken as needed over a period of 12 weeks, in Korean patients with ED, avanafil is an effective and well-tolerated therapy for ED of broad-spectrum aetiology and severity. OBJECTIVE To evaluate the efficacy and safety of avanafil, a new potent selective phosphodiesterase type 5 (PDE5) inhibitor, in patients with erectile dysfunction (ED)., PATIENTS AND METHODS The present study was a multicentre, randomized, double-blind, placebo-controlled, fix-dosed phase three clinical trial involving 200 patients with ED., The subjects were treated with placebo or avanafil (100 or 200 mg) for 12 weeks and were asked to complete the International Index of Erectile Function (IIEF), the Sexual Encounter Profile (SEP) diary, and the Global Assessment Questionnaire (GAQ)., The primary outcome variable was the change from baseline for IIEF erectile function domain (EFD) score., The secondary outcome variables were SEP Q2 and Q3, the shift to normal rate (EFD ≥ 26), and response to the GAQ., RESULTS Compared with placebo, patients who took 100 or 200 mg of avanafil had significantly improved IIEF-EFD score., There were similar results when comparing Q2 and Q3 in the SEP diary and the GAQ., Flushing was the most common treatment-related adverse event., Most adverse events were transient and mild or moderate in severity., CONCLUSION Avanafil is an effective and well-tolerated therapy for ED of broad-spectrum aetiology and severity. [ABSTRACT FROM AUTHOR]

Abstract: We developed a novel method for harvesting endothelial cells from blood vessels of freshly obtained cancer and adjacent normal tissue of human breast, and compared the response of the cancer-derived endothelial cells (CECs) and normal tissue-derived endothelial cells (NECs) to ionizing radiation. In brief, when tissues were embedded in Matrigel and cultured in endothelial cell culture medium (ECM) containing growth factors, endothelial cells grew out of the tissues. The endothelial cells were harvested and cultured as monolayer cells in plates coated with gelatin, and the cells of 2nd–5th passages were used for experiments. Both CECs and NECs expressed almost the same levels of surface markers CD31, CD105 and TEM-8 (tumor endothelial marker-8), which are known to be expressed in angiogenic endothelial cells, i.e., mitotically active endothelial cells. Furthermore, both CECs and NECs were able to migrate into experimental wound in the monolayer culture, and also to form capillary-like tubes on Matrigel-coated plates. However, the radiation-induced suppressions of migration and capillary-like tube formations were greater for CECs than NECs from the same patients. In addition, in vitro clonogenic survival assays demonstrated that CECs were far more radiosensitive than NECs. In summary, we have developed a simple and efficient new method for isolating endothelial cells from cancer and normal tissue, and demonstrated for the first time that endothelial cells of human breast cancer are significantly more radiosensitive than their normal counterparts from the same patients. [Copyright &y& Elsevier]

ABSTRACT Introduction. A proper cavernous endothelial cell culture system would be advantageous for the study of the pathophysiologic mechanisms involved in endothelial dysfunction and erectile dysfunction (ED). Aim. To establish a nonenzymatic technique, which we termed the 'Matrigel-based sprouting endothelial cell culture system,' for the isolation of mouse cavernous endothelial cells (MCECs) and an in vitro model that mimics in vivo situation for diabetes-induced ED. Methods. For primary MCEC culture, mouse cavernous tissue was implanted into Matrigel and sprouting cells from the tissue were subcultivated. To establish an in vitro model for diabetes-induced ED, the primary cultured MCECs were exposed to a normal-glucose (5 mmoL) or a high-glucose (30 mmoL) condition for 48 hours. Main Outcome Measures. The purity of isolated cells was determined by fluorescence-activated cell sorting analysis. MCECs incubated under the normal- or the high-glucose condition were used for Western blot, cyclic guanosine monophosphate (cGMP) quantification, and in vitro angiogenesis assay. Results. We could consistently isolate high-purity MCECs (about 97%) with the Matrigel-based sprouting endothelial cell culture system. MCECs were subcultured up to the fifth passage and no significant changes were noted in endothelial cell morphology or purity. The phosphorylation of Akt and eNOS and the cGMP concentration were significantly lower in MCECs exposed to high glucose than in those exposed to normal glucose. MCECs exposed to the normal-glucose condition formed well-organized capillary-like structures, whereas derangements in tube formation were noted in MCECs exposed to high glucose. The protein expression of transforming growth factor-β1 (TGF-β1) and phospho-Smad2 was significantly increased by exposure to high glucose. Conclusion. The Matrigel-based sprouting endothelial cell culture system is a simple, technically feasible, and reproducible technique for isolating pure cavernous endothelial cells in mice. An in vitro model for diabetic ED will be a valuable tool for evaluating the angiogenic potential of novel endogenous or synthetic modulators. Yin GN, Ryu J-K, Kwon M-H, Shin SH, Jin HR, Song K-M, Choi MJ, Kang D-Y, Kim WJ, and Suh J-K. Matrigel-based sprouting endothelial cell culture system from mouse corpus cavernosum is potentially useful for the study of endothelial and erectile dysfunction related to high-glucose exposure. J Sex Med 2012;9:1777-1789. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction. Transforming growth factor-β1 (TGF-β1) has been identified as an important fibrogenic cytokine associated with Peyronie's disease (PD). Aim. The aim of this study was to study the differential expression of the TGF-β1 and Smad transcription factors in plaque tissue from PD patients and to determine the antifibrotic effect of SKI2162 (SK Chemicals, Seoul, South Korea), a novel small-molecule inhibitor of activin receptor-like kinase 5 (ALK5), a type I receptor of TGF-β, in primary fibroblasts derived from human PD plaque. Methods. Plaque tissue was isolated from five PD patients, and tunica albuginea tissue was obtained from four control patients. Plaque tissues from a patient with PD were used for primary fibroblast culture. Fibroblasts were pretreated with SKI2162 (10 µM) and then stimulated with TGF-β1 (10 ng/mL). Main Outcome Measures. The plaque or tunica albuginea tissue was stained with Masson's trichrome or antibody to TGF-β1, phospho-Smad2 (P-Smad2), and P-Smad3. Protein was extracted from treated fibroblasts for Western blotting, and the membranes were probed with antibody to P-Smad2/Smad2, P-Smad3/Smad3, plasminogen activator inhibitor-1, fibronectin, collagen I, and collagen IV. We also determined the inhibitory effect of SKI2162 on TGF-β1-induced nuclear translocation of Smad2/3 in fibroblasts. Results. The plaque tissue from PD patients showed higher TGF-β1, P-Smad2, and P-Smad3 immunoreactivity than did the tunica albuginea tissue from control patients. SKI2162 not only blocked TGF-β1-induced phosphorylation and nuclear translocation of Smad2 and Smad3, but also inhibited the production of extracellular matrix markers in fibroblasts derived from human PD plaque. Conclusion. In light of the pivotal role of TGF-β and Smads in the pathogenesis of PD, pharmacologic inhibition of ALK5 may represent a novel targeted approach to treating PD. Piao S, Choi MJ, Tumurbaatar M, Kim WJ, Jin H-R, Shin SH, Tuvshintur B, Yin GN, Song JS, Kwon M-H, Lee S-J, Han J-Y, Kim S-J, Ryu J-K, and Suh J-K. Transforming growth factor (TGF)-β type I receptor kinase (ALK5) inhibitor alleviates profibrotic TGF-β1 responses in fibroblasts derived from Peyronie's plaque. J Sex Med 2010;7:3385-3395. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction. With the advent of genetically engineered mice, it seems important to develop a mouse model of cavernous nerve injury (CNI). Aim. To establish a mouse model of CNI induced either by nerve crushing or by neurectomy and to evaluate time-dependent derangements in penile hemodynamics in vivo and subsequent histologic alterations in the cavernous tissue. Methods. Twelve-week-old C57BL/6J mice were divided into 4 groups (N = 36 per group): control, sham operation, bilateral cavernous nerve crush, and bilateral cavernous neurectomy group. Main Outcome Measures. Three days and 1, 2, 4, 8, and 12 weeks after CNI, erectile function was measured by electrical stimulation of the cavernous nerve. The penis was then harvested and TUNEL was performed. Immunohistochemical analysis was performed assaying for caspase-3, transforming growth factor-β1 (TGF-β1), phospho-Smad2, PECAM-1, factor VIII, and smooth muscle α-actin. The numbers of apoptotic cells and phospho-Smad2-immunopositive cells in endothelial cells or smooth muscle cells were counted. Results. Erectile function was significantly less in the cavernous nerve crushing and neurectomy groups than in the control or sham group. This difference was observed at the earliest time point assayed (day 3) and persisted up to 4 weeks after nerve crushing and to 12 weeks after neurectomy. The apoptotic index peaked at 1 or 2 weeks after CNI and decreased thereafter. Cavernous TGF-β1 and phospho-Smad expression was also increased after CNI. The numbers of apoptotic cells and phospho-Smad2-immunopositive cells in cavernous endothelial cells and smooth muscle cells were significantly greater in the cavernous nerve crush and cavernous neurectomy groups than in the control or sham group. Conclusion. The mouse is a useful model for studying pathophysiologic mechanisms involved in erectile dysfunction after CNI. Early intervention to prevent apoptosis in smooth muscle cells and endothelial cells or to inhibit cavernous tissue fibrosis is required to restore erectile function. Jin H-R, Chung YG, Kim WJ, Zhang LW, Piao S, Tuvshintur B, Yin GN, Shin SH, Tumurbaatar M, Han J-Y, Ryu J-K, and Suh J-K. A mouse model of cavernous nerve injury-induced erectile dysfunction: Functional and morphological characterization of the corpus cavernosum. J Sex Med 2010;7:3351-3364. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: To evaluate how the expression of angiogenic factors and their downstream target molecules, which are potentially involved in penile homeostasis, is related to erectile dysfunction in a rat model of hypercholesterolemia. Methods: Fifty-six 2-month-old male Sprague-Dawley rats were included in this study. The control animals (n = 28) were fed a normal diet, and the experimental animals (n = 28) were fed a diet containing 4% cholesterol and 1% cholic acid for 3 months. Erectile function was evaluated by cavernous nerve electrical stimulation, and cavernous tissue was harvested for histologic examination (n = 12, respectively). Cavernous tissue specimens from the remaining rats were used for reverse transcriptase–polymerase chain reaction (RT-PCR), Western blot, or cyclic guanosine monophosphate (cGMP) measurement. Results: The ratio of maximal intracavernous pressure to mean arterial pressure was significantly lower in the hypercholesterolemic rats than in the controls (P <0.01). Analysis by RT-PCR and Western blot showed significantly lower gene expression of vascular endothelial growth factor (VEGF), angiopoietin-1, and angiopoietin-2 and significantly lower protein expression of VEGF, angiopoietin-1, angiopoietin-2, the ratio of phospho-Akt to Akt, and phospho-endothelial nitric oxide synthase (eNOS) to eNOS in hypercholesterolemic rats than in controls. Cavernous tissue cGMP concentrations and endothelial area were also significantly lower in hypercholesterolemic rats than in controls (P <0.01). Conclusions: Downregulation of the expression of the angiogenic factors and their downstream signal molecules, and decreased endothelial content in the corpus cavernosum of hypercholesterolemic rats might play important roles in the deterioration of erectile function. [Copyright &y& Elsevier]

Hypercholesterolemia-related endothelial cell dysfunction and decreased endothelium-derived nitric oxide formation may account for impaired angiogenesis and subsequent erectile dysfunction. Angiopoietin-1 (Ang1) is a critical angiogenic factor for vascular maturation and enhances vascular endothelial growth factor (VEGF)-induced angiogenesis in a complementary manner. We hypothesized that combined adenovirus-delivered human Ang1 (ad-Ang1) and VEGF165 (ad-VEGF165) gene transfer might promote angiogenesis cooperatively in a rat model of hypercholesterolemic erectile dysfunction and result in a recovery of erectile function. Ad-Ang1 and ad-VEGF165 were injected either alone or in combination into the corpus cavernosum of the penis. Combined gene transfer of both ad-Ang1 and ad-VEGF165 significantly increased cavernous angiogenesis, eNOS phosphorylation, and cGMP expression compared with that in the groups treated with either therapy alone. Erectile function, as evaluated by electrical stimulation of the cavernous nerve 2 and 8 weeks after treatment, was completely restored in the combined treatment group, whereas intracavernous injection of either ad-Ang1 or ad-VEGF165 alone elicited partial improvement. The results indicate that combined application of angiogenic factors may enhance cavernous angiogenesis cooperatively by reinforcing the endothelium both structurally and functionally, which results in an additive effect on erectile function in hypercholesterolemic rats.Molecular Therapy (2006) 13, 705–715; doi: 10.1016/j.ymthe.2005.10.016 [ABSTRACT FROM AUTHOR]

Purpose: To identify the optimal photobiomodulation (PBM) parameters using molecular, histological, and erectile function analysis in cavernous nerve injury., Materials and Methods: A cavernous nerve injury was induced in 8-week-old C57BL/6J male mice that were subsequently divided randomly into age-matched control groups. Erectile function tests, penile histology, and Western blotting were performed 2 weeks after surgery and PBM treatment., Results: The PBM treatment was administered for five consecutive days with a light-emitted diode (LED) device that delivers 660 nm±3% RED light, and near infra-red 830 nm±2% promptly administered following nerve-crushing surgery and achieved a notable restoration of erectile function approximately 90% of the control values. Subsequent in-vitro and ex-vivo analyses revealed the regeneration of neurovascular connections in both the dorsal root ganglion and major pelvic ganglion, characterized by the sprouting of neurites. Furthermore, the expression levels of neurotrophic, survival, and angiogenic factors exhibited a substantial increase across all groups subjected to PBM treatment., Conclusions: The utilization of PBM employing LED with 660 nm, 830 nm, and combination of both these wavelengths, exhibited significant efficacy to restore erectile function in a murine model of cavernous nerve injury. Thus, the PBM emerges as a potent therapeutic modality with notable advantages such as efficacy, noninvasiveness, and non-pharmacological interventions for erectile dysfunction caused by nerve injury., Competing Interests: The authors have nothing to disclose., (Copyright © 2024 Korean Society for Sexual Medicine and Andrology.)

Erectile dysfunction (ED) affects a significant proportion of men aged 40-70 and is caused by cavernous tissue dysfunction. Presently, the most common treatment for ED is phosphodiesterase 5 inhibitors; however, this is less effective in patients with severe vascular disease such as diabetic ED. Therefore, there is a need for development of new treatment, which requires a better understanding of the cavernous microenvironment and cell-cell communications under diabetic condition. Pericytes are vital in penile erection; however, their dysfunction due to diabetes remains unclear. In this study, we performed single-cell RNA sequencing to understand the cellular landscape of cavernous tissues and cell type-specific transcriptional changes in diabetic ED. We found a decreased expression of genes associated with collagen or extracellular matrix organization and angiogenesis in diabetic fibroblasts, chondrocytes, myofibroblasts, valve-related lymphatic endothelial cells, and pericytes. Moreover, the newly identified pericyte-specific marker, Limb Bud-Heart (Lbh) , in mouse and human cavernous tissues, clearly distinguishing pericytes from smooth muscle cells. Cell-cell interaction analysis revealed that pericytes are involved in angiogenesis, adhesion, and migration by communicating with other cell types in the corpus cavernosum; however, these interactions were highly reduced under diabetic conditions. Lbh expression is low in diabetic pericytes, and overexpression of LBH prevents erectile function by regulating neurovascular regeneration. Furthermore, the LBH-interacting proteins (Crystallin Alpha B and Vimentin) were identified in mouse cavernous pericytes through LC-MS/MS analysis, indicating that their interactions were critical for maintaining pericyte function. Thus, our study reveals novel targets and insights into the pathogenesis of ED in patients with diabetes., Competing Interests: SB, GY, JO, JS, JR No competing interests declared, JP Reviewing editor, eLife, (© 2023, Bae, Yin, Ock et al.)

As a peripheral nerve injury disease, cavernous nerve injury (CNI) caused by prostate cancer surgery and other pelvic surgery causes organic damage to cavernous blood vessels and nerves, thereby significantly attenuating the response to phosphodiesterase-5 inhibitors. Here, we investigated the role of heme-binding protein 1 (Hebp1) in erectile function using a mouse model of bilateral CNI, which is known to promote angiogenesis and improve erection in diabetic mice. We found a potent neurovascular regenerative effect of Hebp1 in CNI mice, demonstrating that exogenously delivered Hebp1 improved erectile function by promoting the survival of cavernous endothelial-mural cells and neurons. We further found that endogenous Hebp1 delivered by mouse cavernous pericyte (MCP)-derived extracellular vesicles promoted neurovascular regeneration in CNI mice. Moreover, Hebp1 achieved these effects by reducing vascular permeability through regulation of claudin family proteins. Our findings provide new insights into Hebp1 as a neurovascular regeneration factor and demonstrate its potential therapeutic application to various peripheral nerve injuries., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The serum glycoprotein leucine-rich ɑ-2-glycoprotein 1 (LRG1), primarily produced by hepatocytes and neutrophils, is a multifunctional protein that modulates various signaling cascades, mainly TGFβ signaling. Serum LRG1 and neutrophil-derived LRG1 have different molecular weights due to differences in glycosylation, but the impact of the differential glycan composition in LRG1 on its cellular function is largely unknown. We previously reported that LRG1 can promote both angiogenic and neurotrophic processes under hyperglycemic conditions by interacting with LPHN2. Here, we determined the crystal structure of LRG1, identifying the horseshoe-like solenoid structure of LRG1 and its four N-glycosylation sites. In addition, our biochemical and cell-biological analyses found that the deglycosylation of LRG1, particularly the removal of glycans on N325, is critical for the high-affinity binding of LRG1 to LPHN2 and thus promotes LRG1/LPHN2-mediated angiogenic and neurotrophic processes in mouse tissue explants, even under normal glucose conditions. Moreover, the intracavernous administration of deglycosylated LRG1 in a diabetic mouse model ameliorated vascular and neurological abnormalities and restored erectile function. Collectively, these data indicate a novel role of LRG1 glycans as molecular switches that can tune the range of LRG1's cellular functions, particularly the LRG1/LPHN2 signaling axis., (© 2023. The Author(s).)

Background: The incidence of diabetic erectile dysfunction (ED) is rapidly increasing, and due to the severe angiopathy caused by diabetes, current drugs are ineffective at treating ED. Insulin-like growth factor-binding protein 5 (IGFBP5) promotes cell death and induces apoptosis in various cell types., Objectives: To evaluate the effectiveness of IGFBP5 knockdown in improving erectile function in diabetic mice., Materials and Methods: Diabetes was induced by injecting streptozotocin (STZ) intraperitoneally into male 8-week-old C57BL/6 mice. Eight weeks after diabetes induction, mice were divided into four groups: a nondiabetic control group and three STZ-induced diabetic mice groups, which were administered intracavernous injections of phosphate buffered saline, scrambled control shRNA, or shRNA targeting mouse IGFBP5 (shIGFBP5) lentivirus particles. Two weeks later, we measured erectile function by electrically stimulating the bilateral cavernous nerve. To mimic diabetic angiopathy, primary cavernous endothelial cells (MCECs) from healthy mice were cultured and treated with glucose., Results: IGFBP5 expression in MCECs or cavernous tissues were significantly increased under diabetic conditions, and knockdown of IGFBP5 induced MCECs angiogenic activity under high-glucose conditions. STZ-induced diabetic mice had reduced erectile function, but shIGFBP5 treatment resulted in significant improvements (to 90% of the nondiabetic control group level). Furthermore, in diabetic mice, numbers of cavernous endothelial cells, pericytes, and neuronal cells were increased by shIGFBP5 treatment, which also increased eNOS Ser 1177 phosphorylation, decreased permeability and apoptosis of cavernous endothelial cells. In addition, IGFBP5 was found to mediate the AKT, ERK, p38 signaling pathways., Discussion and Conclusion: Knockdown of IGFBP5 improved erectile function in diabetic mice by promoting cell proliferation and reducing apoptosis and permeability. Local inhibition of IGFBP5 expression may provide a new treatment strategy for diabetic ED and other ischemic vascular or neurological diseases., (© 2022 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology.)

Purpose: Diabetes mellitus, one of the major causes of erectile dysfunction, leads to a poor response to phosphodiesterase-5 inhibitors. Heat shock protein 70 (Hsp70), a ubiquitous molecular chaperone, is known to play a role in cell survival and neuroprotection. Here, we aimed to assess whether and how Hsp70 improves erectile function in diabetic mice., Materials and Methods: Eight-week-old male C57BL/6 mice and Hsp70-Tg mice were used in this study. We injected Hsp70 protein into the penis of streptozotocin (STZ)-induced diabetic mice. Detailed mechanisms were evaluated in WT or Hsp70-Tg mice under normal and diabetic conditions. Primary MCECs, and MPG and DRG tissues were cultivated under normal-glucose and high-glucose conditions., Results: Using Hsp70-Tg mice or Hsp70 protein administration, we demonstrate that elevated levels of Hsp70 restores erectile function in diabetic mice. We found that cystathionine gamma-lyase (Cse) is a novel target of Hsp70 in this process, showing that Hsp70-Cse acts through the SDF1/HO-1/PI3K/Akt/eNOS/NF-κB p65 pathway to exert its neurovascular regeneration-promoting effects. Coimmunoprecipitation and pull-down assays using mouse cavernous endothelial cells treated with Hsp70 demonstrated physical interactions between Hsp70 and Cse with a dissociation constant of 1.8 nmol/L., Conclusions: Our findings provide novel and solid evidence that Hsp70 acts through a Cse-dependent mechanism to mediate neurovascular regeneration and restoration of erectile function under diabetic conditions., Competing Interests: The authors have nothing to disclose., (Copyright © 2022 Korean Society for Sexual Medicine and Andrology.)

Diabetes mellitus is one of the main causes of erectile dysfunction (ED). Men with diabetic ED do not respond well to oral phosphodiesterase-5 inhibitors owing to neurovascular dysfunction. Pericyte-derived extracellular vesicle-mimetic nanovesicles (PC-NVs) are known to promote nerve regeneration in a mouse model of cavernous nerve injury. Here, we report that administration of PC-NVs effectively promoted penile angiogenesis and neural regeneration under diabetic conditions, thereby improving erectile function. Specifically, PC-NVs induced endothelial proliferation and migration and reduced cell apoptosis under diabetic conditions. In addition, PC-NVs induced neural regeneration in STZ-induced diabetic mice in dorsal root ganglion and major pelvic ganglion explants in vivo and ex vivo under high-glucose conditions. We found that lipocalin 2 (Lcn2) is a new target of PC-NVs in this process, demonstrating that PC-NVs exert their angiogenic and nerve-regeneration effects by activating MAP kinase and PI3K/Akt and suppressing P53 signaling pathway in an Lcn2-dependent manner. Our findings provide new conclusive evidence that PC-NVs can promote neurovascular regeneration and recovery of erectile function under diabetic conditions via an Lcn2-dependent mechanism. Thus, local administration of PC-NVs may be a promising treatment strategy for the treatment of diabetic ED., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)