Yajun Ruan

Taurine Supplementation Improves Erectile Function in Rats with Streptozotocin-induced Type 1 Diabetes via Amelioration of Penile Fibrosis and Endothelial Dysfunction

INTRODUCTION For patients with diabetes, erectile dysfunction (ED) is common and greatly affects quality of life. However, these patients often exhibit a poor response to first-line oral phosphodiesterase type 5 inhibitors. AIM To investigate whether taurine, a sulfur-containing amino acid, affects diabetic ED (DED). METHODS Type 1 diabetes mellitus was induced in male rats by using streptozotocin. After 12 weeks, an apomorphine test was conducted to confirm DED. Only rats with DED were administered taurine or vehicle for 4 weeks. Age-matched nondiabetic rats were administered saline intraperitoneally for 4 weeks. MAIN OUTCOME MEASURES Erectile function was evaluated by electrical stimulation of the cavernous nerve. Histologic and molecular alterations of the corpus cavernosum also were analyzed. RESULTS Erectile function was significantly reduced in the diabetic rats compared with in the nondiabetic rats, and was improved in the diabetic rats treated with taurine. The corpus cavernosum of the rats with DED exhibited severe fibrosis and decreased smooth muscle content. Deposition of extracellular matrix proteins was increased in the diabetic rats, while expression of endothelial nitric oxide synthase/cyclic guanosine monophosphate/nitric oxide pathway-related proteins was reduced. Taurine supplementation ameliorated erectile response as well as histologic and molecular alterations. CONCLUSION Taurine supplementation improves erectile function in rats with DED probably by potential antifibrotic activity. This finding provides evidence for a potential new therapy for DED.

Stem Cell Therapy for Diabetic Erectile Dysfunction in Rats: A Meta-Analysis

Introduction Stem cell therapy is a novel method for the treatment of diabetic erectile dysfunction (ED). Many relative animal studies have been done to evaluate the efficacy of this therapy in rats. Aims This meta-analysis was performed to compare the efficacy of different stem cell therapies, to evaluate the influential factors and to determine the optimal stem cell therapeutic strategy for diabetic ED. Methods We searched the studies analyzing the efficacy of stem cell therapy for diabetic ED in rats published before September 30, 2015 in PubMed, Web of Science and EBSCO. A random effects meta-analysis was conducted to assess the outcomes of stem cell therapy. Subgroup analysis was also performed by separating these studies based on their different characteristics. Changes in the ratio of intracavernous pressure (ICP) to mean arterial pressure (MAP) and in the structure of the cavernous body were compared. Results 10 studies with 302 rats were enrolled in this meta-analysis. Pooled analysis of these studies showed a beneficial effect of stem cell therapy in improving erectile function of diabetic rats (SMD 4.03, 95% CI = 3.22 to 4.84, P< 0.001). In the stem cell therapy group, both the smooth muscle and endothelium content were much more than those in control group. There was also significant increase in the expression of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS), the ratio of smooth muscle to collagen, as well as the secretion of vascular endothelial growth factor (VEGF). Besides, apoptotic cells were reduced by stem cell treatment. The subgroup analysis indicated that modified stem cells were more effective than those without modification. Conclusions Our results confirmed that stem cell therapy could apparently improve the erectile function of diabetic rats. Some specific modification, especially the gene modification with growth factors, could improve the efficacy of stem cell therapy. Stem cell therapy has potential to be an effective therapeutic strategy for diabetic ED.

Overexpression of p53 activated by small activating RNA suppresses the growth of human prostate cancer cells

Previous research has reported that a particular double-stranded RNA, named dsP53-285, has the capacity to induce expression of the tumor suppressor gene TP53 in chimpanzee cells by targeting its promoter. Usually, it is the wild-type p53 protein, rather than mutants, which exhibits potent cancer-inhibiting effects. In addition, nonhuman primates, such as chimpanzees, share almost identical genome sequences with humans. This prompted us to speculate whether dsP53-285 can trigger wild-type p53 protein expression in human prostate cancer (PCa) cells and consequently suppress cell growth. The human PCa cell lines LNCaP and DU145 were transfected with dsP53-285 for 72 hours. Compared with the dsControl and mock transfection groups, expression of both p53 messenger RNA and p53 protein was significantly enhanced after dsP53-285 transfection, and this enhancement was followed by upregulation of p21, which indirectly indicated that dsP53-285 induced wild-type p53 expression. Moreover, overexpression of wild-type p53 mediated by dsP53-285 downregulated the expression of Cyclin D1 and cyclin-dependent kinase 4/6, thereby inducing PCa cell cycle arrest in G0/G1 phase and then inhibiting cell proliferation and clonogenicity. More importantly, dsP53-285 suppressed PCa cells mainly by modulating wild-type p53 expression. In conclusion, our study provides evidence that dsP53-285 can significantly stimulate wild-type p53 expression in the human PCa cell lines LNCaP and DU145 and can exert potent antitumor effects.

Human tissue kallikrein 1 ameliorates erectile function via modulation of macroautophagy in aged transgenic rats

Previously, we have demonstrated that human tissue kallikrein 1 (hKLK1) improves age‐related erectile dysfunction (ED). Autophagy has been implicated in age‐related diseases, including ED. However, the molecular mechanisms underlying hKLK1‐mediated amelioration of age‐related ED via regulation of autophagy remains unknown. To explore the potential mechanism, male wild‐type Sprague‐Dawley rats (WTR) and transgenic rats harboring human KLK1 (TGR) were bred till 4 or 18 months of age and divided into three groups: young WTR (yWTR) as the control group, aged WTR (aWTR) group, and aged TGR (aTGR) group. The erectile function of each rat was evaluated using cavernous nerve electrostimulation. The ratio of intracavernous pressure/mean arterial pressure (ICP/MAP) and total ICP were also measured. Western blotting, immunohistochemistry, and transmission electron microscopy were performed to detect the levels of autophagy. The expression levels of related signaling pathways were determined by western blotting and immunohistochemistry. We found that hKLK1 improved the impaired erectile function of aged rats. Compared to the yWTR and aTGR groups, the aWTR group showed reduced smooth muscle/collagen ratio, fewer autophagosomes, and lower expression of Beclin 1 and LC3‐II, which indicate impaired smooth muscle function and low level of autophagy in the smooth muscle cells. Moreover, the PI3K/Akt/mTOR signaling pathway, which is considered to be a negative regulator of autophagy, was upregulated in the aWTR group. hKLK1 may partially restore erectile function in aged transgenic rats by upregulating protective autophagy via the PI3K/Akt/mTOR pathway. These observations indicate that hKLK1 is a potential gene therapy candidate for age‐related ED.

AB088. FTY720 supplementation partially improves erectile dysfunction in rats with streptozotocin-induced type 1 diabetes through inhibition of endothelial dysfunction and corporal fibrosis

Background To investigate whether FTY720, approved in 2010 for the treatment of patients with the relapsing-remitting form of multiple sclerosis, could ameliorate erectile dysfunction induced by diabetes mellitus (DMED). Methods Thirty-two Sprague-Dawley rats (8 weeks old) were induced type I DM and the other eight rats formed the control (n=8). Eight weeks later, 17 rats with DMED tested with an apomorphine test were divided in two groups: DMED (n=8) and DMED + FTY720 (1 mg/kg/d; n=9). Treatment of FTY720 lasted for 4 weeks. Results Impaired erectile function, inhibited S1P3/Akt/NO/cGMP activity, serious corporal fibrosis and over-activated pathways (the Smad and non-Smad) were found in the DMED group compared with the control, while FTY720 partly but significantly improved these pathological changes induced by DM. Conclusions FTY720 supplementation inhibited endothelial dysfunction and corporal fibrosis, ultimately leading to partial improvement of DMED in rats. This finding provides evidence for a potential treatment method for DMED.

MP81-14 HUMAN TISSUE KALLIKREIN 1 AMELIORATES ERECTILE FUNCTION VIA MODULATING AUTOPHAGY AND ACTIVATING HIF-1?/COX-2 PATHWAY IN AGED TRANSGENIC RATS

normalized to KCl). Data are presented as means SEM. Data were statistically analyzed using a one way ANOVA followed by Tukeys test(GraphPad Prism software). RESULTS: Vaginal wet weight was decreased (P<0.05) in OVXVV animals compared to SHVV, an effect reversed by local estrogen delivery. Qualitative analysis of vaginal cross sections indicated reversal of ovariectomy induced atrophy of the vaginal muscularis with estrogen treatment. In vitro contractility studies with carbachol demonstrated a trend of a lower EC50 (increased sensitivity) of vaginal strips obtained from OVXVV animals compared to SHVV and OVXVE. The amplitude of contraction to 10 uM carbachol was greater of proximal strips from OVXVV animals compared to SHVV and OVXVE (P<0.05). CONCLUSIONS: Our results indicate that vaginal estrogen is effective at reversing not only OVX induced atrophy of the epithelium but also the vaginal muscularis. We report an increased contractile response to carbachol in OVXVV animals, an effect also reversed by vaginal estrogen. Interestingly, previous studies have shown an increase in vaginal sensory innervation in ovariectomized rodents. More studies are needed to evaluate changes in autonomic innervation with this animal model to identify new therapeutic uses of vaginal estrogen treatment.

AB155. High-throughput sequencing of small RNA component of penile in a post-radical prostatectomy model of erectile dysfunction.

Objective The introduction of nerve-sparing radical prostatectomy represents a milestone in the treatment of prostate cancer. However, a certain percentage of cancer survivors still suffer from erectile dysfunction. Recent research has stated that using PDE 5-inhibitors after radical prostatectomy may lead to biochemical recurrence. This study was performed to identify the expression profile of small RNA in rats with neurogenic erectile dysfunction, and to investigate possible genes and signaling pathways involving in the disease. Methods Neurogenic erectile dysfunction (ED) was induced in male rats by bilateral cavernous nerve crushing injury (BCNI). After 28 days, RNA was isolated from the corpus cavernosum (CC) of both control rats and neurogenic ED rats. Small RNA sequencing was conducted using an Illumina Hiseq 2500/2000 platform. Candidate small RNAs were validated by rael-time polymerase chain reaction. Results Intracavernous pressure (ICP) was significantly decreased in BCNI group compared with SHAM group. Real time PCR validated that miR-9a-5p, miR-203a-5p, miR-378a-3p and miR-3557-5p were upregulated, and meanwhile miR-3084a-3p was downregulated. Conclusion Small RNA, including microRNA, may play an important role in the regulation of genes in CC and some certain miRs may participate in post-prostatectomy ED. Further studies will be designed to investigate the specific mechanisms of these changes.

AB096. Taurine supplementation improves erectile function in rats with streptozotocin-induced type 1 diabetes via amelioration of penile fibrosis and endothelial dysfunction

Objective For patients with diabetes, erectile dysfunction (ED) is common and greatly affects quality of life. However, these patients often exhibit a poor response to first-line oral phosphodiesterase type 5 inhibitors. The aim of this study was to investigate whether taurine, a sulfur-containing amino acid, affects diabetic ED (DED). Methods Type 1 diabetes mellitus was induced in male rats using streptozotocin. After 12 weeks, an apomorphine test was conducted to confirm DED. Only rats with DED were administered taurine or vehicle for four weeks. Age-matched nondiabetic rats were administered saline intraperitoneally for four weeks. Erectile function was evaluated by electrical stimulation of the cavernous nerve. Histologic and molecular alterations of the corpus cavernosum also were analyzed. Results Erectile function was significantly reduced in the diabetic rats compared with in the nondiabetic rats, and was ameliorated in the diabetic rats treated with taurine. The corpus cavernosum of the rats with DED exhibited severe fibrosis and decreased smooth muscle content. Deposition of extracellular matrix proteins was increased in the diabetic rats, while expression of endothelial nitric oxide synthase/cyclic guanosine monophosphate/nitric oxide pathway–related proteins was reduced. Taurine supplementation restored erectile response as well as histologic and molecular alterations. Conclusions Taurine supplementation improves erectile function in rats with DED probably by potential antifibrotic activity. This finding provides evidence for a potential new therapy for DED.

AB156. Taurine ameliorates erectile function in streptozocin-induced type 1 diabetic rats via multiple signaling pathways

Objective PDE5 inhibitors represent the first line therapy for treatment of ED. However, diabetic patients have poorer response compared with normal patients. The aim of this study was to determine whether taurine, a sulfur-containing amino acid, affects diabetic erectile dysfunction. Methods Type 1 diabetes mellitus was induced in male rats by streptozotocin (60 mg/kg, intraperitoneally). After 12 weeks, apomorphine test was conducted to confirm diabetic erectile dysfunction (DED). Only DED rats were administered taurine (400 mg/kg/day, intraperitoneally) or vehicle, for 4 weeks. Age-matched control, nondiabetic, rats were treated with saline intraperitoneally for 4 weeks. At week 16, after a 2-day washout, erectile function was evaluated. Peniles were harvested for Western blot analysis of RhoA, ROCK-1, ROCK-2, eNOS, nNOS, NADPH oxidase subunit gp91phox. Results Erectile function was significantly destroyed in diabetic rats compared with nondiabetic rats and was ameliorated in diabetic rats treated with taurine. In diabetic rats, RhoA, ROCK-1, ROCK-2 and gp91phox protein expressions were increased, whereas eNOS and nNOS expressions were decreased compared with nondiabetic rats, and both were reversed in diabetic rats treated with taurine. Conclusions Taurine improves erectile function in diabetic rats probably by inhibiting RhoA/Rock and activating NOS/NO signaling pathways. This may provide a potential new therapy for diabetic ED.