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质-蛋白质相互作用是必要的适当eNOS功能。其中最重要的eNOS-蛋白质相互作用，可能会影响eNOS调节血管系统，包括阴茎血管床，eNOS结合小窝蛋白-1和热休克蛋白（HSP）90。虽然小窝蛋白-1促进eNOS运输到小窝和eNOS信号复合物的适当组织，但它干扰eNOS随后的生物学作用。Hsp 90促进eNOS活化并保持eNOS的偶联活性。目前，很少有人知道eNOS-蛋白质相互作用的作用和调节，在调节酶的活性和其功能的相关性，在脉管系统，包括阴茎血管床。该提案的总体目标是通过eNOS-蛋白质相互作用研究阴茎中eNOS调节的分子机制，及其在阴茎勃起中的生理意义。调查将涉及评价eNOS与小窝蛋白-1和HspQO在小鼠血脂异常模型中的相互作用，作为本调查的范例。我们将首先评估在高胆固醇血症诱导的勃起功能障碍（艾德）中，在松弛或勃起条件下，eNOS与小窝蛋白-1和HspQO的相互作用是否受损，同时eNOS功能缺陷。接下来，我们将评估保留eNOS-蛋白质相互作用是否保留eNOS功能和勃起功能。该假设将在用L-4F（一种载脂蛋白-A-I模拟物）处理的血脂异常小鼠中进行测试，所述L-4F部分地通过维持最佳eNOS-蛋白质相互作用来积极影响eNOS功能。第三，我们将评估NAD（P）H氧化酶和解偶联的eNOS引起的超氧化物生成增加是否是高胆固醇血症小鼠eNOS-蛋白质相互作用受损和艾德的基础。这将在存在和不存在夹竹桃苷诱导的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生理和病理生理条件下血管组织中NO介导的反应至关重要。这项研究有望阐明eNOS在阴茎中调控的新分子机制及其在勃起生理学中的生理意义。同时，提示eNOS特异性调控通路可能成为治疗ED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.