Ke Rao

S-allyl cysteine restores erectile function through inhibition of reactive oxygen species generation in diabetic rats

Excessive production of reactive oxygen species (ROS) by an overactive nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system in penile tissue is an important mechanism of erectile dysfunction (ED). S‐allyl cysteine (SAC), a bioactive component derived from garlic, was recently reported to exert versatile antioxidant properties. We hypothesized that SAC would be able to resolve diabetes‐related ED by reducing ROS generation, and designed this study to investigate this possibility as well as to determine the related underlying mechanisms. A streptozotocin‐induced diabetes rat model was established and used for comparative analysis of 4‐week treatment regimens with insulin or SAC. The ratio of maximal intracavernous pressure (ICP) to mean arterial blood pressure (MAP) was measured to determine erectile function. Differential levels of ROS, NADPH oxidase subunits, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling pathway, and apoptosis were evaluated in cavernous tissues. Max ICP/MAP was found to be markedly decreased in untreated diabetic rats; SAC, but not insulin, treatment restored the ratio to baseline (in non‐diabetic untreated controls). The corpus cavernosum of untreated diabetic rats showed increased p47phox and p67phox expression, ROS production and penile apoptotic index, and decreased phospho‐endothelial nitric oxide synthase (phospho‐eNOS, Ser1177) expression, cGMP concentration, B‐cell lymphoma 2 (Bcl‐2)/Bcl‐2‐associated X protein (Bax) ratio and smooth muscle cell number. SAC treatment normalized all the diabetes‐induced effects, whereas insulin treatment partially normalized the alterations, but produced no effects on P47phox expression, penile ROS level, apoptotic index, Bcl‐2/Bax ratio and smooth muscle cell number. Collectively, these data indicate that SAC treatment can restore erectile function in diabetic rats by preventing ROS formation through modulation of NADPH oxidase subunit expression. Furthermore, the poor efficacy of conventional insulin treatment for diabetic ED may be associated with an elevated level of ROS in penile tissue.

Apocynin Improves Erectile Function in Diabetic Rats through Regulation of NADPH Oxidase Expression

INTRODUCTION Diabetes is a risk factor for erectile dysfunction (ED). The proposed mechanisms responsible for diabetic ED are associated with an increase in reactive oxygen species (ROS) production, overactivity of RhoA/ROCK signaling pathway and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, as seen in experimental models of diabetic rats. AIM The aim of this study was to investigate whether NADPH oxidase inhibitor apocynin can ameliorate Streptozotocin (STZ)-induced diabetes-related ED by reducing the ROS production and inhibiting the activity of RhoA/ROCK signaling pathway. METHODS The diabetic rats were treated with and without the NADPH oxidase inhibitor apocynin. MAIN OUTCOME MEASURES Erectile responses were evaluated by determining mean arterial blood pressure (MAP) and intracavernosal pressure (ICP) with electrical stimulation of the cavernous nerve. Levels of mRNA expression were measured by real-time polymerase chain reaction (RT-PCR). Levels of protein expression were examined by Western Blot. ROS production was measured by dihydroethidium (DHE) staining and thiobarbituric acid reactive substances assay. RESULTS The ratio of Maximum ICP-to-MAP (MaxICP/MAP) was significantly decreased in diabetic ED rats, compared to that of age-matched control rats (P < 0.05). Apocynin improved erectile function of diabetic rats (P < 0.05). Expression levels of RhoA (cytosol), nNOS and eNOS were reduced, compared to those of control rats (P < 0.05). Apocynin significantly elevated their expression levels in diabetic rats (P < 0.05). Expression levels of ROCK1, RhoA (membrane fraction), p-MYPT1 and NADPH oxidase subunits p47(phox) and p67(phox) were increased in diabetic rats when compared to those of control rats (P < 0.05), and it was observed that apocynin significantly reduced their expression levels in diabetic rats (P < 0.05). ROS production was increased in diabetic rats when compared to that of control rats (P < 0.05), the effect of apocynin was a reduction in the ROS production in diabetic rats (P < 0.05). CONCLUSION NADPH oxidase inhibitor apocynin can ameliorate diabetes-related ED by reducing the ROS production and inhibiting the activity of RhoA/ROCK signaling pathway.

Up‐regulation of VEGF by Small Activator RNA in Human Corpus Cavernosum Smooth Muscle Cells

INTRODUCTION Functional failure of smooth muscle cells and endothelial cells in corpus cavernosum contributes to erectile dysfunction (ED) in aging men. Given that vascular endothelial growth factor (VEGF) may improve the function of smooth muscle cells and endothelial cells through different mechanisms, it is thus expected that increasing the expression of VEGF may have beneficial effects on erectile function. AIM The aim of this article is to explore the possibility that VEGF can be induced by ribonucleic acid activation (RNAa) technology, and VEGF induction by RNAa has the potential of treating ED. METHODS Primary human corpus cavernosum smooth muscle cells (CCSMCs) were isolated and cultured in vitro. The expression of α-smooth muscle actin was detected by immunohistochemistry to identify CCSMCs. A previously identified VEGF promoter-targeted small activator RNA (saRNA, double-stranded [ds]VEGF-706) and a negative control dsRNA were chemically synthesized. Cultured human CCSMCs were transfected with the saRNAs. The expression of VEGF messenger RNA (mRNA) and protein in transfected CCSMCs was evaluated by real-time polymerase chain reaction (RT-PCR) and Western blotting assay, respectively. Immunofluorescent staining was also used to confirm VEGF protein expression in cultured CCSMCs. MAIN OUTCOME MEASURE The expression of VEGF was assessed by RT quantitative PCR, Western blotting, and immunofluorescence assays. RESULTS After transfection, RT quantitative PCR analysis showed that the expression of VEGF mRNA was significantly induced in dsVEGF-706 transfected cells compared with cells receiving control treatments (P < 0.05). Consistent with mRNA induction, Western blotting and immunofluorescence analysis showed that VEGF protein expression was also induced by dsVEGF-706. CONCLUSION VEGF expression can be activated by RNAa in primary human CCSMCs, suggesting a potential application of RNAa-mediated VEGF activation for the treatment of ED.

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.

Testosterone improves erectile function through inhibition of reactive oxygen species generation in castrated rats

Testosterone is overwhelmingly important in regulating erectile physiology. However, the associated molecular mechanisms are poorly understood. The purpose of this study was to explore the effects and mechanisms of testosterone in erectile dysfunction (ED) in castrated rats. Forty male Sprague-Dawley rats were randomized to four groups (control, sham-operated, castration and castration-with-testosterone-replacement). Reactive oxygen species (ROS) production was measured by dihydroethidium (DHE) staining. Erectile function was assessed by the recording of intracavernous pressure (ICP) and mean arterial blood pressure (MAP). Protein expression levels were examined by western blotting. We found that castration reduced erectile function and that testosterone restored it. Nitric oxide synthase (NOS) activity was decrease in the castrated rats, and testosterone administration attenuated this decrease (each p < 0.05). The testosterone, dihydrotestosterone, cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) concentrations were lower in the castrated rats, and testosterone restored these levels (each p < 0.05). Furthermore, the cyclooxygenase-2 (COX-2) and prostacyclin synthase (PTGIS) expression levels and phospho-endothelial nitric oxide synthase (p-eNOS, Ser1177)/endothelial nitric oxide synthase (eNOS) ratio were reduced in the castrated rats compared with the controls (each p < 0.05). In addition, the p40phox and p67phox expression levels were increased in the castrated rats, and testosterone reversed these changes (each p < 0.05). Overall, our results demonstrate that testosterone ameliorates ED after castration by reducing ROS production and increasing the activity of the eNOS/cGMP and COX-2/PTGIS/cAMP signaling pathways.

Local anesthesia for transrectal ultrasound-guided biopsy of the prostate: A meta-analysis

A meta-analysis was performed to evaluate the efficacy of local anesthesia in alleviating pain during prostate biopsy. We searched relevant articles in PubMed and Embase. The included studies should be randomized controlled trials (RCT) using local anesthesia to alleviate pain during biopsy, which was recorded by a pain scale. Analgesic efficacy of different local anesthesia techniques were analyzed, including intrarectal local anesthesia (IRLA), periprostatic nerve block (PNB), pelvic plexus block (PPB) and intraprostatic local anesthesia (IPLA). We included 46 RCTs. PNB significantly reduced pain score compared with placebo (−1.27 [95% confidence interval [95% CI] −1.72, −0.82]) or no injection (−1.01 [95% CI −1.2, −0.82]). IRLA with prilocaine-lidocaine cream could also reduced pain (−0.45 [95% CI −0.76, −0.15]), while the IRLA with lidocaine gel was not effective (−0.1 [95% CI −0.24, 0.04]). PNB lateral to the neurovascular bundle had better analgesic effect than at prostate apex (P = 0.02). Combination use of PPB and IRLA considerably alleviated pain of patients compared with the combination of PNB and IRLA (−1.32 [95% CI −1.59, −1.06]). In conclusion, local anesthesia could alleviate patients’ pain during the prostate biopsy. PNB was not so effective as PPB.

Clinical assessment and genomic landscape of a consanguineous family with three Kallmann syndrome descendants.

Although some genes that cause Kallmann syndrome (KS) have been identified by traditional linkage analysis and candidate gene techniques, the syndromes molecular etiology in the majority of patients remains poorly understood. In this paper, we present the clinical assessments of a consanguineous Han Chinese family with three KS descendants. To understand the molecular etiology of KS from a genome-wide perspective, we investigated the genome-wide profile of structural variation in this family using the Affymetrix Genome-Wide Human SNP Array 6.0 platform. The results revealed that the three affected individuals had common copy number variants (microdeletions) on chromosomes 1p21.1, 2q32.2, 8q21.13, 14q21.2 and Xp22.31. Moreover, the copy number variants on Xp22.31 were located in the intron of KAL1, which causes X-linked KS. Two PCR assays were performed on these regions to validate the results obtained using the chips. In addition, genomic microdeletions in this region were verified in one of 29 Han Chinese sporadic KS cases and one of four other family cases, but not in 26 Han Chinese sporadic normosmic idiopathic hypogonadotropic hypogonadism cases and 100 unrelated Han Chinese normal controls. Our results provide a novel insight into the relative contributions of certain copy number variants to KSs molecular etiology and generate a list of interesting candidate regions for further studies.

Hyperlipidemia impairs erectile function in rats by causing cavernosal fibrosis

Men with hyperlipidemia are more likely to have erectile dysfunction (ED) than those without hyperlipidemia, but the mechanisms are not fully understood. The aim of this study was to investigate the underlying mechanism of ED caused by hyperlipidemia. Fourteen 8‐week‐old Sprague–Dawley rats were randomly divided into two groups: a control group and a hyperlipidemia group (fed chow containing 4% cholesterol and 1% cholic acid). After 6 months, we assessed erectile function by performing cavernous nerve electrostimulation followed by intracavernosal pressure/mean arterial pressure measurements, as well as plasma lipid profile assessment in all rats. A transferase‐mediated nick end labeling (TUNEL) assay, immunohistochemical staining and Western blotting were performed to determine the levels of apoptosis, autophagy and fibrosis in the penile tissue. Compared with the control group, the hyperlipidemia group exhibited: (i) increased plasma lipid levels; (ii) decreased erectile function; (iii) a decreased smooth muscle/collagen ratio; (iv) increased fibrosis; (v) increased apoptosis and decreased autophagy. Overall, hyperlipidemia may attenuate erectile function in rats by causing of cavernosal fibrosis.

Reduced corporal fibrosis to protect erectile function by inhibiting the Rho-kinase/LIM-kinase/cofilin pathway in the aged transgenic rat harboring human tissue kallikrein 1

Our previous studies have demonstrated that erectile function was preserved in aged transgenic rats (TGR) harboring the human tissue kallikrein 1 (hKLK1), while the molecular level of hKLK1 on corporal fibrosis to inhibit age-related erectile dysfunction (ED) is poorly understood. Male wild-type Sprague-Dawley rats (WTR) and TGR harboring the hKLK1 gene were fed to 4- or 18-month-old and divided into three groups: young WTR (yWTR) as the control, aged WTR (aWTR), and aged TGR (aTGR). Erectile function of all rats was assessed by cavernous nerve electrostimulation method. Masson′s trichrome staining was used to evaluate corporal fibrosis in the corpus cavernosum. We found that the erectile function of rats in the aWTR group was significantly lower than that of other two groups. Masson′s trichrome staining revealed that compared with those of the yWTR and aTGR groups, the ratio of smooth muscle cell (SMC)/collagen (C) was significantly lower in the aWTR group. Immunohistochemistry and Western blotting analysis were performed, and results demonstrated that expression of α-SMA was lower, while expressions of transforming growth factor-β 1 (TGF-β1), RhoA, ROCK1, p-MYPT1, p-LIMK2, and p-cofilin were higher in the aWTR group compared with those in other two groups. However, LIMK2 and cofilin expressions did not differ among three groups. Taken together, these results indicated that the RhoA/ROCK1/LIMK/cofilin pathway may be involved in the corporal fibrosis caused by advanced age, and hKLK1 may reduce this corporal fibrosis by inhibiting the activation of this pathway to ameliorate age-related ED.

Expression of oxytocin receptor in diabetic rat penis

Oxytocin receptor (OTR) expressed in the rat penis and mediated the contractility of the corpus cavernosum smooth muscle both in vitro and in vivo, and OTR could maintain penile detumescence; however, the expression of OTR in diabetic rat penis remains unknown. In the present study, we investigated the expression of OTR in diabetic rat penis. The experimental rats were randomly divided into control group and STZ‐diabetic rats group. The expressions of mRNA and protein were examined by real‐time quantitative PCR, Western blotting and immunohistochemistry respectively. Erectile function was evaluated by measuring intracavernous pressure following electrostimulation of the cavernous nerves. mRNA and protein expression of OTR significantly increased in diabetic rats group compared with the control group. Erectile function of diabetic rats group significantly decreased compared with the control group. Our data showed that the expression of OTR significantly increased in diabetic rats group and OTR may involve in the development of diabetic erectile dysfunction.