Role of Testosterone Induction of Hydrogen Sulfide in Erectile Dysfunction

项目摘要/摘要 睾丸素不足是一种不利的健康状况，影响着越来越多的男性。它 可能是前列腺癌治疗引起的，但也可能是与心脏代谢不良有关的条件引起的 健康，如肥胖、糖尿病和高血压。勃起功能障碍(ED)是男性的常见症状 患有睾丸素不足。这项拟议的研究试图找出为什么睾丸激素具有保护性 对勃起系统的影响。具体地说，睾酮激活胱硫醚γ裂解酶(CSE)的可能性 将会被调查。CSE是血管系统中产生硫化氢的主要酶。氢 硫化物是一种重要的细胞信号分子，已知具有抗氧化、抗炎和 血管扩张特性。睾酮的血管扩张作用将在转基因药物中进行研究 缺乏CSE基因的小鼠，以及它们的未经修饰的产仔对照。这些组织的组织片段 动物也将与不同浓度的睾丸激素孵化，之后，硫化氢 产能将被衡量。海绵体和动脉的组织切片 负责为阴茎提供血液的人将被用于这些研究，其中包括髂内动脉 以及阴部内动脉的近段和远段。 以往的研究表明，慢性氧化应激是ED发病的一个致病因素 对睾丸激素不足的反应。硫化氢施加细胞信号的一种机制是 通过与蛋白质硫醇基团结合，称为硫水化作用。据推测，硫化氢在 这种方式促进了核相关因子2(NRF2)向细胞核的易位。NRF2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 硫化氢诱导小鼠抗氧化性防御和缓解勃起功能障碍 将对睾丸素不足进行调查。雄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缓释药物 硫化氢供体。干预后，通过测量勃起功能来评估勃起功能 海绵体内压力因电刺激海绵体神经而改变。神经血管， 将评估海绵体、髂内动脉和 使用体外肌图系统对阴部内动脉的远端和近端节段进行测量。的表达 在这些组织中，由Nrf2调控的细胞保护和抗氧化基因将通过定量RT- 聚合酶链式反应。这些组织中NRF2的胞浆和核含量将通过细胞分离和 蛋白质印迹。阴茎的氧化还原状态将通过测量体内的活性氧物种来检查 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.