eNOS-Protein Interaction in the Penis

描述（由申请人提供）：内皮型一氧化氮合酶（eNOS）是阴茎勃起的重要介质。适当的亚细胞运输和蛋白-蛋白相互作用是正常eNOS功能所必需的。eNOS与eNOS蛋白之间最重要的相互作用可能影响eNOS在脉管系统（包括阴茎血管床）中的调控，其中eNOS与caveolin-1和热休克蛋白（Hsp）90的结合。虽然小泡蛋白-1促进eNOS向小泡转运和eNOS信号复合体的正常组织，但它会干扰eNOS的后续生物作用。Hsp90促进eNOS激活并保持eNOS的偶联活性。目前，关于enos -蛋白相互作用在包括阴茎血管床在内的血管系统中对酶活性的调节及其功能相关性的作用和调控知之甚少。本研究的总体目标是通过eNOS-蛋白相互作用研究eNOS调控阴茎的分子机制及其在阴茎勃起中的生理意义。该研究将在小鼠血脂异常模型中评估eNOS与caveolin-1和HspQO的相互作用，作为本研究的范例。我们将首先评估eNOS与caveolin-1和HspQO的相互作用是否在高胆固醇血症引起的勃起功能障碍（ED）中受损，同时eNOS功能存在缺陷。接下来，我们将评估保留eNOS-蛋白相互作用是否保留eNOS功能和勃起功能。这一假设将在用L-4F治疗的血脂异常小鼠中进行验证，L-4F是一种载脂蛋白a -l模拟物，通过维持最佳的eNOS-蛋白相互作用，在一定程度上对eNOS功能产生积极影响。第三，我们将评估NAD(P)H氧化酶和未偶联的eNOS产生的超氧化物是否在高胆固醇血症小鼠中导致eNOS蛋白相互作用和ED受损。这将在有或没有罗布麻素诱导的NAD(P)H氧化酶抑制的高胆固醇血症小鼠中进行测试。阐明eNOS调控的分子机制对于更好地理解血管组织在生理和病理生理条件下no介导的反应至关重要。本研究旨在阐明eNOS调控阴茎的新分子机制及其在勃起生理学中的意义。同时，它可能提示一个特定的eNOS调控通路作为治疗ED的可能的新分子靶点。

DESCRIPTION (provided by applicant): Endothelial nitric oxide synthase (eNOS) is an important mediator of penile erection. Appropriate subcellular trafficking and protein-protein interactions are necessary for proper eNOS function. Among the most important eNOS-protein interactions that may affect eNOS regulation in the vasculature including the penile vascular bed, are eNOS binding with caveolin-1 and heat shock protein (Hsp)90. While caveolin-1 facilitates eNOS trafficking to caveolae and proper organization of the eNOS signaling complex, it interferes with subsequent biological actions of eNOS. Hsp90 facilitates eNOS activation and keeps coupled eNOS activity. Currently very little is known about the role and regulation of eNOS-protein interactions in the regulation of the enzyme's activity and its functional relevance in the vasculature including the penile vascular bed. The overall goal of the proposal is to investigate the molecular mechanisms of eNOS regulation in the penis by eNOS-protein interactions, and its physiological significance in penile erection. The investigation will involve evaluation of eNOS interactions with caveolin-1 and HspQO in a mouse dyslipidemic model as a paradigm for this investigation. We will first evaluate whether eNOS interactions with caveolin-1 and HspQO are impaired in hypercholesterolemia-induced erectile dysfunction (ED) under flaccid or erect conditions, in parallel with a defect in eNOS function. Next, we will evaluate whether preserving eNOS-protein interactions preserves eNOS function and erectile function. This hypothesis will be tested in dyslipidemic mice treated with L-4F, an apolipoprotein-A-l mimetic, which positively influences eNOS function in part by maintaining an optimal eNOS-protein interaction. Third, we will evaluate whether increased superoxide production by NAD(P)H oxidase and uncoupled eNOS underlies impaired eNOS-protein interaction and ED in the hypercholestero- lemic mouse. This will be tested in hypercholesterolemic mice with and without apocynin-induced inhibition of NAD(P)H oxidase. Elucidation of the molecular mechanisms of eNOS regulation is crucial for a better understanding of NO-mediated responses in vascular tissues under physiologic and pathophysiologic circumstances. The proposed investigation is expected to elucidate a novel molecular mechanism of eNOS regulation in the penis and its physiological significance in erection physiology. At the same time, it may suggest a specific eNOS regulatory pathway as a possible new molecular target for treating ED.