Role of Testosterone Induction of Hydrogen Sulfide in Erectile Dysfunction

项目概要/摘要 睾酮不足是一种不良的健康状况，影响越来越多的男性。它 可能是由前列腺癌治疗引起的，但也可能是由与心脏代谢不良相关的疾病引起的。 肥胖、糖尿病和高血压等健康问题。勃起功能障碍（艾德）是男性常见的症状 睾丸激素不足这项拟议中的研究旨在确定为什么睾丸激素具有保护作用， 对勃起系统的影响具体来说，睾酮激活胱硫醚γ-裂解酶（CSE）的可能性 将被调查。CSE是在脉管系统中产生硫化氢的主要酶。氢 硫化物是一种重要细胞信号分子，已知其具有抗氧化、抗炎和 血管舒张特性。睾酮的血管舒张作用将在转基因动物中进行研究。 缺乏CSE基因的小鼠，以及它们未修饰的同窝对照。这些组织切片 动物也将与不同浓度的睾丸激素一起孵育，之后硫化氢 生产能力将被衡量。海绵体和动脉的组织切片 负责为阴茎供血的动脉将用于这些研究，包括髂内动脉 以及阴部内动脉的近端和远端部分。 以往的研究表明，慢性氧化应激是艾德发病的一个致病因素， 睾酮不足的反应硫化氢发挥细胞信号传导的一种机制是 通过与蛋白质巯基结合，称为巯基化。据推测，硫化氢的作用， 以这种方式促进核相关因子2（Nrf 2）易位到细胞核。NRF 2是一个重要的 调节许多细胞保护和抗氧化基因转录的转录因子。的能力 硫化氢诱导抗氧化防御和缓解勃起功能障碍小鼠模型 将研究睾酮不足。雄性小鼠将接受假手术或阉割手术，之后 去势的小鼠将保持不治疗，或接受低剂量或高剂量的口服活性的缓释药物， 硫化氢供体。干预后，勃起功能将通过测量 海绵体内压力响应于海绵体神经的电刺激而变化。神经血管， 将评估海绵体、髂内动脉和 使用离体肌描记系统测量阴部内动脉的远端和近端段。表达 将通过定量RT-PCR在这些组织中评估受Nrf 2调节的细胞保护和抗氧化基因。 PCR法将通过细胞分级分离测量这些组织中Nrf 2的细胞溶质和细胞核含量， Western印迹阴茎的氧化还原状态将通过使用生物传感器测量体内活性氧来检查。 微透析技术

Project Summary/Abstract Testosterone insufficiency is an adverse health condition that affects an increasing number of men. It may be caused by prostate cancer treatment, but also by conditions associated with poor cardiometabolic health such as obesity, diabetes, and hypertension. Erectile dysfunction (ED) is a common symptom in men with testosterone insufficiency. The proposed research seeks to identify why testosterone has a protective effect on the erectile system. Specifically, the possibility that testosterone activates cystathionine γ-lyase (CSE) will be investigated. CSE is the primary enzyme that produces hydrogen sulfide in the vasculature. Hydrogen sulfide is an important cellular signaling molecule that is known to have antioxidant, anti-inflammatory, and vasodilatory properties. The vasodilatory effects of testosterone will be investigated in genetically modified mice lacking the CSE gene, as well as their unmodified littermate controls. Tissue segments from these animals will also be incubated with varying concentrations of testosterone, after which hydrogen sulfide production capacity will be measured. Tissue segments from the corpus cavernosum and the arteries responsible for supplying blood to the penis will be used for these studies, which include the internal iliac artery and proximal and distal segments of the internal pudendal artery. Previous studies indicate that chronic oxidative stress is a causative factor in ED pathogenesis in response to testosterone insufficiency. One mechanism by which hydrogen sulfide exerts cellular signaling is through binding to protein thiol groups, termed sulfhydration. It is hypothesized that hydrogen sulfide acts in such a manner to promote the nuclear related factor 2 (Nrf2) translocation to the nucleus. Nrf2 is an important transcription factor that regulates transcription of many cytoprotective and antioxidant genes. The ability of hydrogen sulfide to induce antioxidant defense and alleviate erectile dysfunction in a mouse model of testosterone insufficiency will be investigated. Male mice will receive a sham or castration surgery, after which castrated mice will remain untreated, or receive a low-dose or a high-dose of an orally active, slow-releasing hydrogen sulfide donor. Following the intervention, erectile function will be assessed by measuring intracavernous pressure changes in response to electrical stimulation of the cavernous nerve. Neurovascular, endothelial, and smooth muscle function will be assessed in the corpus cavernosum, internal iliac artery, and distal and proximal segments of the internal pudendal artery using an ex vivo myograph system. Expression of cytoprotective and antioxidant genes regulated by Nrf2 will be assessed in these tissues by quantitative RT- PCR. Cytosolic and nuclear content of Nrf2 in these tissues will be measured by cellular fractionation and Western blot. The penile redox state will be examined by measuring in vivo reactive oxygen species using a microdialysis technique.