Erectile Function In Diabetic Rats Research Articles

The effects of the urotensin-II receptor antagonist palosuran treatment on the corpora cavernosa of streptozotocin-induced diabetic rats

ObjectiveTo investigate the effects of treatment with palosuran, a urotensin receptor blocker, on molecular changes in the corpora cavernosa (CC) and erectile function in diabetic rats. MethodsStreptozotocin-induced diabetic rats were treated with palosuran 300 mg/kg per day for 6 weeks. Contraction of CC induced by potassium chloride, phenylephrine, and Nω-Nitro-L-arginine methyl ester and relaxation of CC induced by electric field stimulation (EFS) and sodium nitroprusside (SNP) (endothelium-dependent and endothelium-independent stimuli, respectively), and Y-27632 (Rho-kinase inhibitor) were examined in organ baths. Direct contraction or relaxation induced by palosuran and urotensin-II (U-II) were also evaluated. Expressions of nitric oxide synthetase (NOS) enzymes, RhoA, oxidative stress regulators, and U-II were analyzed by Western blotting or immunohistochemisty. ResultsInduction of diabetes in rats resulted in decreased relaxant response to SNP, decreased pD2 value of SNP, attenuated relaxant response to Y-27632 as well as the decreased RhoA expression in CC. Palosuran treatment of diabetic rats reversed all of these parameters; however, it further impaired the already weakened relaxation of diabetic CC in response to EFS. Although induction of diabetes did not change U-II expression in CC significantly, palosuran treatment reduced U-II expression in diabetic CC. The expression level of nNOS was lowered in diabetic CC; however palosuran treatment did not change the decreased nNOS expression. In vitro exposure of diabetic CC strips to palosuran produced a direct relaxant response. ConclusionPalosuran treatment did not affect the expression of NOS enzymes or reduced nitrergic conduction induced by EFS stimulation in diabetic CC. However, while directly triggering a relaxant response, it did not induce a prominent contraction either by decreasing U-II expression, or increasing the sensitivity of CC to NO which suggested that palosuran has the potential to support erectile function. Further and comprehensive studies are required to clarify this issue.

Ursodeoxycholic acid ameliorates erectile dysfunction and corporal fibrosis in diabetic rats by inhibiting the TGF-β1/Smad2 pathway.

Corporal tissue fibrosis is critical in diabetes-associated erectile dysfunction. Transforming growth factor-β1/Small mothers against decapentaplegic-2 (TGF-β1/Smad2) contributes to the induction of fibrosis in corporal tissue. Smad7 is accepted as a general negative regulator of Smad signaling, although its role in corporal fibrosis is unknown. Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid used for biliary and liver related disorders and has antifibrotic effects in the liver. This study investigated the effects of UDCA on diabetic erectile dysfunction. Forty-eight male Spraque Dawley rats were divided into six groups: nondiabetic (n = 6), nondiabetic+20 mg/kg UDCA (n = 6), nondiabetic+80 mg/kg UDCA (n = 6), diabetic (n = 10), diabetic+20 mg/kg UDCA (n = 10), diabetic+80 mg/kg UDCA (n = 10). Diabetes was induced by intraperitoneal injection of 60 mg/kg Streptozocin. UDCA (20 and 80 mg/kg/day) or saline was subsequently administered via oral gavage for 56 days. Erectile function was evaluated as measurement of maximum intracavernosal pressure (m-ICP)/mean arterial pressure (MAP) and total ICP/MAP. Corporal tissues were evaluated by Western blotting and Masson's trichrome staining. Electrical stimulation-induced m-ICP/MAP responses were higher in UDCA-treated diabetic rats compared to untreated diabetic rats, respectively (20 mg/kg; 4 V: 0.77 ± 0.11 vs 0.45 ± 0.09, p = 0.0001 and 80 mg/kg; 4 V: 0.78 ± 0.11 vs 0.45 ± 0.09, p = 0.0001) UDCA prevented the increase in phospho-Smad2 and fibronectin protein expressions in diabetic corporal tissue both at 20 mg/kg (p = 0.0002, p = 0.002 respectively) and 80 mg/kg doses (p < 0.0001 for both). Smad7 protein expressions were significantly increased in the UDCA-treated diabetic groups compared to the untreated diabetic group (20 mg/kg: p = 0.0079; 80 mg/kg: p = 0.004). Furthermore, UDCA significantly prevented diabetes-induced increase in collagen (20 mg/kg: p = 0.0172; 80 mg/kg: p = 0.0003) and smooth muscle loss (20 mg/kg: p = 0.044; 80 mg/kg: p = 0.039). In conclusion, UDCA has a potential protective effect on erectile function in diabetic rats by altering fibrotic pathways via inhibition of TGF-β1/Smad2 and activation of Smad7.

Ameliorative effect of cranberry on erectile function in diabetic rats

Ameliorative effect of cranberry on erectile function in diabetic rats

Curcumin Attenuates Ferroptosis and Ameliorates Erectile Function in Diabetic Rats by Activating Nrf2/HO-1 Pathway

Previous studies have shown that curcumin has a therapeutic effect on diabetic erectile dysfunction (ED), but the exact mechanism of action remains unclear. In order to ascertain the involvement of ferroptosis in diabetic ED and explore the underlying mechanism by which curcumin mitigates ferroptosis in penile endothelial cells under conditions of high-glucose stimulation, we conducted an investigation utilizing a rat model of diabetes induced by a high-fat diet and streptozotocin injection. The 40 male Sprague–Dawley rats were randomly divided into four groups: blank control, diabetes control, ferroptosis inhibitor treatment, and curcumin treatment. After 8 weeks, the erectile function of all rats was evaluated through electrical stimulation of the cavernous nerve. Histological and molecular changes of the cavernous body were analyzed using western blot and immunohistochemistry. Penile endothelial cells were then treated with appropriate concentrations of high glucose and curcumin to explore the mechanism of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling in curcumin’s ability to alleviate ferroptosis in endothelial cells stimulated by high glucose. According to research, diabetic rats experience a decrease in erectile function, damaged endothelial cells, and ferroptosis in tissues. However, curcumin treatment has been shown to be effective in improving erectile function and related tissue and molecular changes in diabetic rats. Furthermore, in vitro experiments have confirmed that curcumin can inhibit the occurrence of ferroptosis in penile endothelial cells that are stimulated by high glucose through Nrf2/HO-1 signaling. Curcumin has been found to improve the occurrence of penile ED in diabetic penile endothelial cells. This is achieved by inhibiting the level of ferroptosis, and the mechanism behind this improvement may be linked to the upregulation of the expression level of Nrf2/HO-1.

The impact of liraglutide treatment on erectile function of the diabetic rats

Objectives: Glucagon like peptide-1 (GLP-1) is a hormone released from intestinal L-cells following nutrient consumption. It potentiates secretion of insulin from pancreatic beta-cells thus GLP-1 analogues are used for the treatment of type-2 diabetes mellitus( T2DM). This study aims to evaluate impact of GLP-1 receptor agonist liraglutide on erectile function of diabetic rats. Methods: Male Sprague-Dawley rats (n = 30, 13-weeks old, 240-335 gr) were fed with fatty diet for 2-weeks and divided into 3 groups (n = 10 each). The rats in the first group served as controls (Group C) whereas the rats in the remaining two groups were injected with streptozocin and became T2DM for forming diabetic group (Group D) and treatment group (Group DT). Rats in group D received citrate buffer injections whereas rats in the group DT received liraglutide injections (0.3 mg/kg/12h) subcutaneously. Erectile functions of all rats were evaluated with intracavernosal pressure (ICP)/mean arterial pressure (MAP) measurements. Moreover, plasma sex hormone levels (Testosterone, FSH, LH) were measured and histological assessment of midpenile tissue were performed (Collagen-Type-IV, rat epithelial antigen-1, nNOS). Results: Maximum ICP/MAP ratios were 0.790 ± 0.164, 0.263 ± 0.139 and 0.652 ± 0.131 in Group C, Group D and Group DT. Although mean ICP/MAP ratios were similar in Group C and Group DT (p = 0.076), mean ICP/MAP ratio was significantly lower in Group D (p &amp;lt; 0.001). Testosterone and FSH results were significantly lower in the Group D as well (p = 0.001). Histological analyses revealed that nNOS (p &amp;lt; 0.001), rat epithelial antigen-1 (p = 0.016) and muscle/collagen ratio (p = 0.015) were also lower in Group D, compared with the other groups. Conclusions: GLP-1 receptor agonist liraglutide demonstrated protective effects on the erectile tissues of the diabetic rats. Clinical trials are required to confirm if liraglutide treatment has similar beneficial effects on men who have T2DM.

MP27-10 CRISPRA-ENGINEERED ADIPOSE-DERIVED STEM CELLS IMPROVE ERECTILE DYSFUNCTION IN DIABETIC RATS

You have accessJournal of UrologyCME1 Apr 2023MP27-10 CRISPRA-ENGINEERED ADIPOSE-DERIVED STEM CELLS IMPROVE ERECTILE DYSFUNCTION IN DIABETIC RATS Wenchao Xu, Hao Li, Taotao Sun, Jiaxin Wang, Tao Wang, and Jihong Liu Wenchao XuWenchao Xu More articles by this author , Hao LiHao Li More articles by this author , Taotao SunTaotao Sun More articles by this author , Jiaxin WangJiaxin Wang More articles by this author , Tao WangTao Wang More articles by this author , and Jihong LiuJihong Liu More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003255.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Due to the high incidence of diabetes mellitus (DM) and poor response to phosphodiesterase type 5 inhibitor in DM-induced erectile dysfunction (DMED) patients, new therapeutic strategies for DMED are needed. Adipose-derived stem cells (ADSCs) transplantation is considered a promising treatment for DMED but is limited by poor survival and efficacy after transplantation. This study explored the therapeutic effect of CRISPRa-engineered ADSCs overexpressing GPX4 (GPX4-ADSCs) on erectile function in diabetic rats. METHODS: Thirty-two SD rats were randomly divided into four groups: the control, DMED, ADSCs, GPX4-ADSCs groups. Among them, the control group rats were non-diabetic rats, and the latter four groups were all diabetic ED rats of the same age. CRISPRa system was used to overexpress GPX4 in ADSCs. The GPX4-ADSCs group was treated with intracavernous injections of GPX4-ADSCs, while the ADSCs group was treated with ADSCs. Four weeks after transplantation, intracavernous pressure (ICP) and mean arterial pressure (MAP) were measured by electrical stimulation of cavernous nerve, and penile tissue was collected for subsequent testing. RESULTS: ADSCs and GPX4-ADSCs transplantation did not affect the weight or the glucose levels of diabetic rats. Although both the ADSCs group and the GPX4-ADSCs group improved erectile function in diabetic rats, the GPX4-ADSCs group had better improvement than the ADSCs group. In the DMED group, oxidative levels in the corpus cavernosum increased, PI3K/AKT/eNOS signal expression was down-regulated, Caspase3 activity was enhanced, and TGFβ1-Smad2/3-Collagen IV pathway was upregulated, showing obvious oxidative stress, apoptosis and fibrosis. ADSCs and GPX4-ADSCs can reverse these changes caused by diabetes to some extent, and GPX4-ADSCs are more effective than ADSCs. CONCLUSIONS: The CRISPRa-engineered ADSCs overexpressing GPX4 had stronger efficacy in improving erectile function than ADSCs, and the mechanism may involve reducing oxidative stress, apoptosis, and fibrosis, which provides a new strategy for the treatment of DMED. Source of Funding: This research was funded by grants from the National Natural Science Foundation of China (No. 82001536 and No.81873831) and the Fundamental Research Funds for the Central Universities (HUST: YCJJ202201021) © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e366 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wenchao Xu More articles by this author Hao Li More articles by this author Taotao Sun More articles by this author Jiaxin Wang More articles by this author Tao Wang More articles by this author Jihong Liu More articles by this author Expand All Advertisement PDF downloadLoading ...

Engineered Adipose-Derived Stem Cells Overexpressing RXFP1 via CRISPR Activation Ameliorate Erectile Dysfunction in Diabetic Rats.

Due to the high incidence of diabetes mellitus (DM) and poor response to the first-line treatment of DM-induced erectile dysfunction (DMED), new therapeutic strategies for DMED are needed. Adipose-derived stem cell (ADSC) transplantation is considered a promising treatment modality for DMED but is limited by poor survival and efficacy after transplantation. In this study, we aimed to increase the therapeutic effect of DMED by overexpressing the relaxin family peptide receptor 1 (RXFP1) using a clustered regularly interspaced short palindromic repeats activation (CRISPRa) system in ADSCs. Two lentiviruses carrying the CRISPRa system transfected ADSCs to overexpress RXFP1 (RXFP1-ADSCs). The intracavernous injection of ADSCs was performed in DMED rats induced by the intraperitoneal injection of streptozotocin. Four weeks after transplantation, we measured erectile function and collected specimens of the corpus cavernosum for follow-up detection. The results showed that ADSCs improved erectile function in diabetic rats, and the RXFP1-ADSCs were more significant. We detected reduced levels of oxidative stress, apoptosis and fibrosis together with relative normalization of endothelial and smooth muscle cell function in the penis after ADSC transplantation. RXFP1-ADSCs had more potent efficacy in the above alterations compared to negative control ADSCs due to the high levels of survival and paracrine capacity in RXFP1-ADSCs. The results revealed that RXFP1-ADSC transplantation could partially preserve erectile function in DMED rats associated with the regulation of oxidative stress, apoptosis, fibrosis and endothelial and smooth muscle cell dysfunction. RXFP1 may be the new target for the genetic modification of ADSCs, which benefits the management of DMED.

A study of diabetes-induced erectile dysfunction treated with human umbilical cord mesenchymal stem cells.

The present study aimed to assess the value of human umbilical cord mesenchymal stem cells (hUC-MSCs) for the treatment of diabetes-induced erectile dysfunction (DMED). We established a type 1 diabetes model through intra-abdominal streptozotocin injection. After 10 weeks, an apomorphine test was performed to screen the rats for erectile dysfunction (ED). The rats were divided into three groups: normal control group (n=10), DMED group (n=9) and DMED+hUC-MSC group (n=9). After 4 weeks of hUC-MSC therapy, erectile function was evaluated by intracavernous pressure measurements, and penile tissue collagen and smooth muscle were examined by haematoxylin-eosin and Masson's trichrome staining. In addition, western blotting, immunohistochemistry and RT-PCR analysis of TLR4, VEGF and eNOS were performed. The results showed that hUC-MSC treatment restored erectile function (p < .05) and reversed the smooth muscle/collagen ratio changes of DMED rats (p < .05). Furthermore, hUC-MSC treatment inhibited the expression of TLR4 (p < .05) and enhanced VEGF and eNOS expression (p < .05). In conclusion, hUC-MSC treatment restored the erectile function of diabetic rats by inhibiting TLR4, improving corpora cavernosa fibrosis, and increasing VEGF and eNOS expression.

Ipidacrine (Axamon), A Reversible Cholinesterase Inhibitor, Improves Erectile Function in Male Rats With Diabetes Mellitus-Induced Erectile Dysfunction.

ABSTRACTSBackgroundManagement of diabetes mellitus-induced erectile dysfunction (DMED) is challenging because of its insufficient responses to phosphodiesterase type 5 inhibitors.AimTo compare the effects of ipidacrine, a reversible cholinesterase inhibitor, and sildenafil on DMED in a rat model of streptozotocin (STZ)-induced diabetes.MethodsErectile dysfunction (ED) caused by STZ-induced diabetes mellitus was modeled in adult male Wistar rats, which were randomized to 4 groups: untreated diabetic rats, sildenafil (5 mg/kg), ipidacrine (3.6 mg/kg) and ipidacrine (6.7 mg/kg). The test drug (ipidacrine), comparator (sildenafil) or control substance (1% starch solution) were administered orally for 5 days or 14 days. Erectile function was assessed by the change in the maximum intracavernous pressure (ICPmax) following cavernous nerve electrical stimulation. The mean arterial pressure (MAP) was recorded, and the ICPmax/MAP ratio was calculated. Sexual behavior, cholinesterase activity and blood testosterone level tests assessed.Main Outcome MeasureThe quantitative value of ICPmax/MAP 14 days after the start of administration of the test drug and the comparison drug.ResultsAnimals with STZ-induced diabetes mellitus showed a significant decrease in ICPmax and ICPmax/MAP ratio compared to the intact control group. When ipidacrine was administered to rats with DMED for 14 days, an increase in these indicators was noted. It was proved that ipidacrine at a dose of 6.7 mg/kg has noninferiority compared to sildenafil on the DMED model. Significant increase in ICPmax compared to STZ-control after electrostimulation of the cavernous nerve was recorded following administration of ipidacrine at a dose of 6.7 mg/kg (P < .05) and sildenafil at a dose 5 mg/kg (P < .05). Neither the test drug, nor the comparator were associated with increase in testosterone levels in blood; as well both drugs did not promote activation of sexual behavior.Clinical ImplicationsIpidacrine may be considered as an effective therapy for DMED but needs to be verified in human investigations.Strengths & LimitationsThe role of ipidacrine, was firstly demonstrated in rats with DMED. However, the results were obtained in animal experiments, and will be further tested in the study of receptor interactions and the determination of cellular targets.ConclusionThis is the first study to show that administration of ipidacrine, the reversible cholinesterase inhibitor, improved erectile function in diabetic rats and these results may be beneficial in further studies using ipidacrine for treatment of DMED, particularly in non-responders to PDE5 inhibitors.Bykov V, Gushchina E, Morozov S, et al. Ipidacrine (Axamon), A Reversible Cholinesterase Inhibitor, Improves Erectile Function in Male Rats With Diabetes Mellitus-Induced Erectile Dysfunction. Sex Med 2022;10:100477.

NOX1/4 Inhibitor GKT-137831 Improves Erectile Function in Diabetic Rats by ROS Reduction and Endothelial Nitric Oxide Synthase Reconstitution

BackgroundPrevious studies have shown that oxidative stress contributes to hyperglycemia-induced erectile dysfunction. A preferential direct inhibitor of NOX1 and NOX4, GKT-137831, exhibited a strong anti‑oxidative role via blockade of reactive oxygen species (ROS) generation in endothelial cells, but whether GKT-137831 could improve erectile function was not clear. AimOur study was designed to investigate the effect of NOX1/4 inhibition on improving diabetic erectile dysfunction (ED) in rats. MethodsWe used streptozotocin to induce type 1 diabetes mellitus (DM) in 32 male Sprague Dawley (SD) rats (8 weeks old). Eight weeks later, type 1 diabetes mellitus-induced erectile dysfunction (DMED) in rats was confirmed using an apomorphine test. Our study consisted of 3 groups: (i) nondiabetic control group (n = 8), (ii) DMED + vehicle group (DMED group; n = 8), and (iii) DMED + GKT-137831 group (n = 9); GKT-137831 was given as a once-daily intraperitoneal injection for 4 weeks. Cavernous nerve electrostimulation was used to evaluate erectile function. Western blot, ELISA, immunohistochemistry, and immunofluorescence were used to measure expression of specific proteins, and DHE fluorescent probe was performed to detect ROS level. OutcomesIntracavernous pressure (ICP), nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway, oxidative stress level, inflammatory response, corporal autophagy, and apoptosis were measured. ResultsErectile function in the DMED group was significantly impaired compared to the nondiabetic control group, whereas this impairment was improved with GKT-137831 treatment by 70%. Similarly, endothelial function and overactivated oxidative stress in the corpus cavernosum (CC) of the DMED + GKT-137831 group were improved. The DMED group showed serious inflammatory responses and excessive autophagy, which were inhibited by GKT-137831 treatment in the DMED + GKT-137831 group. Clinical TranslationOur study showed improvement in erectile function with GKT-137831 in a diabetic rat ED model. Strength and LimitationsThis study suggested for the first time that GKT-137831, an NOX1/4 inhibitor undergoing clinical trials, is effective in improving erectile function in rats with type 1 DMED. However, we only investigated GKT-137831 treatment of streptozotocin-induced type 1 diabetic rats, and therapeutic evidence in other types of diabetes is lacking. ConclusionGKT-137831 improves erectile function by 70% in type 1 DMED rats and constitutes a promising compound for the treatment of type 1 DMED, likely by inhibition of overactivated oxidative stress, down-regulation of proinflammatory factors, and amelioration of excessive autophagy and endothelial function.B Zhou, Y Chen, H Yuan, et al. NOX1/4 Inhibitor GKT-137831 Improves Erectile Function in Diabetic Rats by ROS Reduction and Endothelial Nitric Oxide Synthase Reconstitution. J Sex Med 2021;18:1970–1983.

Knockdown of miR-423-5p simultaneously upgrades the eNOS and VEGFa pathways in ADSCs and improves erectile function in diabetic rats.

This study aimed to explore the possibility of miR‐423‐5p modified adipose‐derived stem cell (ADSCs) therapy on streptozotocin (STZ)‐induced diabetes mellitus erectile dysfunction (DMED) rats. MiR‐423‐5p was knocked down in ADSCs. ADSCs, NC‐miR‐ADSCs and miR‐ADSCs were co‐cultured with human umbilical vein endothelial cells (HUVECs). Normal and high glucose media were supplemented. The supernatant and HUVECs were collected for assessment of eNOS and VEGFa expression, cell proliferation, and apoptosis. HUVECs co‐cultured with ADSCs or miR‐ADSCs exhibited higher eNOS and VEGFa protein expression levels compared to DM groups. MiR‐ADSCs enhanced HUVEC proliferation compared to the ADSCs and NC‐miR‐ADSCs. Lower apoptotic rates were observed when HUVECs were co‐cultured with miR‐ADSCs, compared to ADSCs and NC‐miR‐ADSCs. Fifteen male Sprague‐Dawley (SD) rats aged 12 weeks were induced to develop diabetes mellitus by intraperitoneal injection with STZ, and five healthy SD rats were used as normal controls. Eight weeks after developing diabetes, the rats received ADSCs and miR‐ADSCs via injection into the corpora cavernosa, whereas normal controls and DM controls were injected with saline. Erectile function and histological assessment of penile tissues were performed 8 weeks after injection. The ICP/MAP indicated that erectile function was impaired in the DM rats compared with the normal group. Injection of ADSCs and miR‐ADSCs improved erectile function significantly and was associated with the overexpression of eNOS and VEGFa. MiR‐423‐5p knockdown in ADSCs ameliorated high glucose‐mediated damage to HUVECs and improved erectile function in DM rats by inducing eNOS and VEGFa overexpression, indicating that miR‐423‐5p may be a potential target in the treatment of DMED.

Effects of Cultured Cordycep militaris on Sexual Performance and Erectile Function in Streptozotocin-Induced Diabetic Male Rats.

Cordyceps militaris (CM), a valuable edible and medicinal fungus, has been used as traditional medicine to treat health conditions, as well as hyposexuality in Asian societies for over a century. Due to the high demand, several artificial cultivation methods have been developed for their biological activities. In this study, CM was cultured on medium that contained white rice and silkworm pupae, and the levels of cordycepin and adenosine, as well as its aphrodisiac effects in diabetes-induced erectile dysfunction (DIED), were evaluated. Diabetic rats were induced by streptozotocin (STZ) injection and administered orally with CM (0.1, 0.5, and 1.0 g/kg BW/day) for 3 weeks. Diabetic rats in negative and positive control groups received vehicle and sildenafil citrate (5 mg/kg), respectively. Results showed the changes in mating behaviour in which mount latency and intromission latency were significantly increased in diabetic rats, compared with the normal control group. Diabetic rats also showed a significant reduction in intracavernosal pressure (ICP) response to cavernous nerve stimulation, sperm count, testosterone level, penile nitric oxide synthase (NOS), and testicular superoxide dismutase (SOD) activities, when compared to the normal control group. Administration of CM (0.1, 0.5, and 1.0 g/kg BW/day) reversed the effects of diabetes on the mating behaviour, and the ICP responses to electrical stimulation. Moreover, the levels of penile NOS, testicular SOD activities, testosterone, and sperm count were significantly increased, and testicular malondialdehyde (MDA) levels were significantly decreased in these treated diabetic rats. Diabetic rats treated with sildenafil showed a significant induction in intromission frequency and NOS and SOD activities, as well as a marked increase in ICP responses. These results suggest that CCM exerts its aphrodisiac effect, possibly through activating testosterone production and suppressing oxidative stress to enhance erectile function in diabetic rats.

Exosomes from adipose-derived stem cells protect against high glucose-induced erectile dysfunction by delivery of corin in a streptozotocin-induced diabetic rat model.

IntroductionIncreasing study have found that stem cell transplantation have a therapeutical effect to diabetes mellitus (DM)-induced erectile dysfunction (ED). So, the aim of this study was to evaluate the beneficial effect of corin from adipose-derived stem cells (ADSCs) on DM-induced ED.MethodsExosomes were isolated from ADSCs (ADSC-EXOs) or from ADSCs in which corin gene expression was silenced by siRNA (siCorin). For in vivo studies, rats with streptozotocin-induced DM were intravenously injected with ADSC-EXOs or siCorin-ADSC-EXOs. Two weeks later, intracavernosal pressure (ICP) and mean arterial pressure (MAP) were measured to assess erectile function, and penile tissues were harvested for further evaluation of levels of inflammatory factors and expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and neuronal nitric oxide synthase (nNOS). We also evaluated the recovery of neurovascular function in penile tissues by immunofluorescence analysis.ResultsThe results showed that ADSC-EXOs restored erectile function in diabetic rats, as determined by the ICP/MAP ratio. Exosomes from ADSCs also promoted neurovascular function and suppressed expression of inflammatory factors. In contrast, the decreased content of corin in exosomes after silencing corin in ADSCs reduced the therapeutic effect of exosomes on ED.ConclusionThese findings demonstrated the therapeutic mechanism underlying the use of ADSC-EXOs for treating ED and the beneficial effect of corin.

The beneficial effect of clove essential oil and its major component, eugenol, on erectile function in diabetic rats.

Diabetic men are at a higher risk of erectile dysfunction (ED). A tropical plant, clove (Syn. Eugenia caryophyllata, Caryophyllus aromaticus L., Syzygium aromaticum (L.) Merr. & L.M. Perry) from the Myrtaceae family has displayed aphrodisiac activity. The present research aimed to investigate the impacts of clove essential oil (CEO) and the ingredient of CEO, eugenol (E) on ED in diabetic rats. We divided Sprague-Dawley rats into control and diabetic groups. Erectile function was evaluated before and after CEO and E intracavernosal injection. CEO- and E-induced relaxation responses were investigated in isolated corpus cavernosum (CC) usingvarious inhibitors. The intracavernous administration of CEO and E restored erectile responses in diabetic rats. CEO and E induced remarkable relaxation in all groups. CEO- and E-induced relaxation responses were partially inhibited after pre-contraction with KCl. Tetraethylammonium and glibenclamide inhibited the relaxation response to CEO. Glibenclamide inhibited maximum relaxation to E. The inhibitors of nitric oxide synthase (NOS), soluble guanylyl cyclase and nifedipine did not change CEO- and E-induced relaxation responses. The current results suggest that CEO and the major compound of the essential oil, E improved diabetes-induced ED in rats, and CEO caused CC relaxation via K+ channels independently NO signalling pathway.

Intracavernosal Adeno-Associated Virus-Mediated S100A1 Gene Transfer Enhances Erectile Function in Diabetic Rats by Promoting Cavernous Angiogenesis via VEGF-A/VEGFR2 Signaling

IntroductionNovel therapeutic targets for diabetes-induced erectile dysfunction (DED) are urgently needed. Previous studies have proved that S100A1, a small Ca2+-binding protein, is a pluripotent regulator of cardiovascular pathophysiology. Its absence is associated with endothelial dysfunction, the central event linking cardiovascular changes in diabetes. However, the role of S100A1 in DED remains unknown. AimTo explore the effect and underlying mechanisms of S100A1 in restoring erectile function in type I diabetic rat model. MethodsDiabetes was induced by intraperitoneal injection of streptozotocin and then screened by apomorphine (APO) to confirm erectile dysfunction. Rats that met the criteria of penile erection were marked as APO-positive; otherwise, the result was APO-negative. In experiment 1, S100A1 gene expression alterations in the corpus cavernosum in moderate and established stages of DED were analyzed. In experiment 2, S100A1 and control GFP gene were delivered into the corpus cavernosum in APO-negative rats by adeno-associated virus (AAV) serotype 9. Erectile function was assessed at 4 weeks after gene therapy. Main Outcome MeasuresErectile response, histologic and molecular alterations. ResultsS100A1 protein was localized to the area surrounding the cavernosal sinusoids in the penis, and it was gradually downregulated synchronized with the progression of DED. Compared with an injection of AAV-GFP, a single injection of AAV-S100A1 significantly restored erectile function in diabetic rats. S100A1 overexpression significantly upregulated the expression of endogenous VEGF-A, promoted VEGFR2 internalization, and subsequently triggered the protein kinase B–endothelial nitric oxide synthase pathway in diabetic erectile tissues. Marked increases in nitric oxide and endothelial content were noted in AAV-S100A1-treated diabetic rats. Clinical ImplicationsLocal S100A1 overexpression may be an alternative therapy for DED and should be further investigated by future clinical studies. Strength & LimitationsThis is the first study demonstrating the angiogenic role of S100A1 in DED, but does not preclude the contribution of the effects of S100A1 in other tissues such as the neuronal tissue on the functional effects observed in erectile responses. ConclusionThe decreased expression of S100A1 during hyperglycemia might be important in the development of erectile dysfunction. S100A1 may play a potential role in restoring erectile function in rats with DED through modulating cavernous angiogenesis.Yu Z, Zhang Y, Tang Z, et al. Intracavernosal Adeno-Associated Virus-Mediated S100A1 Gene Transfer Enhances Erectile Function in Diabetic Rats by Promoting Cavernous Angiogenesis via VEGF-A/VEGFR2 Signaling. J Sex Med 2019;16:1344–1354.

MicroRNA-141 binds to the nerve growth factor receptor associated protein 1 gene and restores the erectile function of diabetic rats through down-regulating the nerve growth factor/neurotrophin receptor p75 (NGF/p75NTR) signaling.

Erectile dysfunction (ED) is one of the major complications in diabetes mellitus (DM). We have previously reported that the nerve growth factor (NGF)/tyrosine kinase receptor (TrkA) signaling is actively involved in DM-induced ED (DMED). Here, we investigate the effect of micro-RNA-141 (miR-141) on the NGF/p75 neurotrophin receptor (p75NTR) signaling and erectile function of diabetic rats. Sprague-Dawlay (SD) rats were used to establish a DMED model. The dual-luciferase reporter gene assay was first performed to identify the nerve growth factor receptor-associated protein 1 (NGFRAP1) gene as the target gene of miR-141. The regulatory mechanisms underlying miR-141 governing NGFRAP1 in vivo were then validated by modulating the expressions of miR-141 and knocking down NGFRAP1. The expressions of miR-141 were decreased while the expressions of NGFRAP1, NGF, and p75NTR were increased in DMED. miR-141 and downregulation of NGFRAP1, respectively, increased the density of corpus cavernosum smooth muscle and the ratio of intracavernosal pressure (ICP)/mean arterial blood pressure (MAP) and promoted the expression of α-actin and desmin as well. miR-141 also upregulated the expressions of NGFRAP1 in DMED, and knockdown of NGFRAP1 inhibited the productions of NGF and p75NTR. Furthermore, miR-141 suppressed the NGF/p75NTR signaling via binding to NGFRAP1. NGF/p75NTR signaling actively participates in the pathogenesis of DMED. miR-141 binds to NGFRAP1 and restores the erectile function of diabetic rats via downregulation of NGF/p75NTR signaling.

Transplantation of adipose tissue-derived stem cell-derived exosomes ameliorates erectile function in diabetic rats.

Mesenchymal stem cells (MSCs) have been considered as an attractive tool for the therapy of diseases. Accumulating evidence indicates that the healing effects of MSCs are mainly related to paracrine action rather than transdifferentiation. Exosomes excreted from MSCs have emerged as physiologically relevant and powerful components of the MSC secretome. However, whether MSC-derived exosomes can improve erectile function of streptozotocin-induced diabetic rats and its mechanism remains unknown. Our previous work showed that adipose tissue-derived stem cells (ADSCs) transplantation could increase endothelial and smooth muscle contents and improve erectile function of diabetic rats. In this study, ADSC-derived exosomes (ADSC-Exo) exhibited in vitro proangiogenic properties, induced the proliferation of endothelial cells and restored erectile function in vivo, as well as decreased fibrosis of corpus cavernosum. In further experiments, we found that ADSC-Exo contained some proangiogenic (miR-126, miR-130a and miR-132) microRNAs and an antifibrotic microRNA family (miR-let7b and miR-let7c). Thus, it is reasonable to postulate that ADSC-Exo transports key functional miRNAs to target cells in a specific manner to improve functional recovery or to activate endogenous repair mechanisms. This proof-of-concept study provides a novel approach for the treatment of diabetic erectile dysfunction.

Intracavernous Injection of Human Umbilical Cord Blood Mononuclear Cells Improves Erectile Dysfunction in Streptozotocin-Induced Diabetic Rats

IntroductionErectile dysfunction (ED) worsens in men with diabetes. Human umbilical cord blood (HUCB), because of its widespread availability and low immunogenicity, is a valuable source for stem cell-based therapies. AimTo determine the effect of intracavernous injection of HUCB mononuclear cells (MNCs) on ED in rats with diabetes induced by streptozotocin. MethodsThirty adult male Sprague-Dawley rats were equally divided into three groups: (i) control, (ii) diabetes induced by streptozotocin (35 mg/kg intravenously for 8 weeks), and (iii) diabetic rats treated with MNCs (1 × 106 cells by intracavernosal injection). The HUCB-MNCs isolated by the Ficoll-Hypaque technique were obtained from eight healthy donors and administered to diabetic rats after 4 weeks. Main Outcome MeasuresThe ratio of intracavernosal pressure to mean arterial pressure ratio; the protein expression of endothelial and neuronal markers, such as von Willebrand factor, neuronal nitric oxide synthase, hypoxia-inducible factor-1α, and vascular endothelium growth factor; and the relative area of smooth muscle to collagen using western blotting and Masson trichrome staining were determined. ResultsDiabetic rats demonstrated a significantly decreased ratio of intracavernosal pressure to mean arterial pressure (0.26 ± 0.04; P < .01) and treatment with MNCs restored erectile function in diabetic rats (0.67 ± 0.05) compared with control rats (0.56 ± 0.02). In bath studies, neurogenic relaxant and contractile responses were significantly decreased in diabetic cavernosal tissues, which were restored by treatment. The ratio of smooth muscle to collagen was partly recovered by treatment, whereas von Willebrand factor levels were not altered in any group. Neuronal nitric oxide synthase and vascular endothelium growth factor levels were decreased, which were not restored by treatment. Increased hypoxia-inducible factor-1α protein expression in the diabetic group was completely normalized in MNC-treated diabetic samples. ConclusionThese results suggest that HUCB-MNC treatment can enhance the recovery of erectile function and promote numerous activities such the contribution of the hypoxia-inducible factor-1α and von Willebrand factor pathway to the neurogenic erectile response of diabetic rats. HUCB-MNCs in the healing process could involve an adaptive regenerative response and appear to be a potential candidate for cell-based therapy in ED of men with diabetes. It is evident that HUCB could provide a realistic therapeutic modality for the treatment of diabetic ED.

137 Superparamagnetic Iron Oxide Nanoparticle Targeting of Adipose Tissue-Derived Stem Cells in Diabetes-Associated Erectile Dysfunction

To explore the effect of Adipose tissue-derived stem cells (ADSCs) labelled with superparamagnetic iron oxide nanoparticles (SPIONs) on improving the erectile function of streptozocin (STZ)-induced diabetic rats with an external magnetic field. Ten-week-old male Sprague Dawley rats were injected either with STZ to induce diabetes or citrate buffer as controls. Rat ADSCs were harvested and labelled with SPIONs, and then transplanted into corpus cavernosum of STZ-induced diabetic rats with or without an external magnetic field. At 28 days after transplantation, all rats were sacrificed for tracking of transplanted cells. Erectile response was assessed by cavernous nerve stimulation. Smooth muscle, endothelium and vascular endothelial growth factor (VEGF) expression in corpora cavernosum were assessed using immunohistochemistry. In vitro studies revealed that stem cell properties were minimally affected by SPION labeling. With magnetic targeting, SPION-labelled ADSCs were visibly attracted toward the magnet field. In vivo experiments, magnetic targeting of ADSCs contributed to long-term cell retention in corpus cavernosum and improved the erectile function of diabetic rats compared with ADSC injection alone. ADSCs were identified in the corpus cavernosums of diabetic rats at 28 days after transplantation, and they were negative for vWF and a-SMA, indicating that ADSCs did not differentiate into endothelial or smooth muscle cells. VEGF expression in the corpus cavernosum was significantly increased in both ADSC-treated groups compared with the PBS-treated group. The underlying mechanism of recovery appears to the paracrine mechanism of transplanted ADSCs.

Effect of BKCa Channel Opener LDD175 on Erectile Function in an In Vivo Diabetic Rat Model

IntroductionThe development of novel therapeutic options is imperative in patients with erectile dysfunction, especially those non-responsive to phosphodiesterase type 5 inhibitors. LDD175, a potent BKCa channel opener, has a relaxation effect on the in vitro cavernosal smooth muscle strip. AimTo investigate the effect of LDD175 on erectile function using in vivo animal disease model. MethodsMale Sprague-Dawley rats were assigned to a normal control group and seven diabetic groups: diabetic control, sildenafil (1 and 5 mg/kg), LDD175 (5 and 10 mg/kg), LDD175 5 mg/kg plus sildenafil 1 mg/kg, and LDD175 10 mg/kg plus tetraethylammonium. Main Outcome MeasuresIntracavernosal pressure (ICP), ratio of ICP to mean arterial pressure (MAP), and the area under curve of ICP/MAP of eight groups were compared using in vivo pelvic nerve stimulation. ResultsThe ICP, ICP/MAP ratio, and area under curve of the ICP/MAP ratio of the normal control rats increased with an increase in electrical field stimulation voltage. All parameters in the diabetic control group were significantly lower than those in the normal control rats, with an electrical field stimulation ranging from 1 to 5 V (P < .05). LDD175 improved the erectile response in diabetic rats in a dose-dependent manner. The combination of sildenafil (1 mg/kg) and LDD175 (5 mg/kg) showed a significant additive effect (P < .05) on the improvement of erectile function compared with sildenafil (1 mg/kg) alone. The enhancement of erectile function by LDD175 was completely blocked by tetraethylammonium. ConclusionThe results showed that the BKCa channel opener LDD175 improved erectile function in an in vivo diabetic rat model. Furthermore, combination therapy of LDD175 and sildenafil had an additive effect on the improvement of erectile function in diabetic rats. LDD175 could be a new candidate for the treatment of erectile dysfunction.