Opiorphin as a master regulator of pathways leading to priapism

Opiorphin 作为导致阴茎异常勃起途径的主要调节剂

• 批准号: 9008835
• 负责人: KELVIN P DAVIES
• 金额: $ 48.85万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE, INC
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-15 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9008835
• 关键词: Affect; Age; Animal Model; Animal Organ; Bathing; Bilateral; Blood; Blood flow; Brain Hypoxia-Ischemia; Cell Line; Cells; Clinical; Clinical Research; Complex; Dependence; Development; Event; Family; Gene Activation; Gene Expression; Gene Expression Regulation; Gene Transfer; Genes; Human; Hypoxia; In Vitro; Intervention; Laboratories; Lead; Life; Mediating; Modeling; Mus; Muscle; Muscle Tonus; Muscle relaxants; Muscle relaxation phase; Organ; Pathway interactions; Patients; Peptides; Pharmacological Treatment; Play; Priapism; Publishing; Rattus; Regulation; Relaxation; Role; Sickle Cell; Sickle Cell Anemia; Small Interfering RNA; Smooth Muscle; Smooth Muscle Myocytes; Staging; Structure of internal iliac artery; System; Testing; Therapeutic Agents; Tissues; Topical application; Translations; Up-Regulation; Work; base; blebbistatin; gene function; gene transfer vector; in vivo; knock-down; men; mouse model; nanoparticle; novel; overexpression; penis; prevent; public health relevance; research study; response; tool

 DESCRIPTION (provided by applicant): Priapism associated with sickle cell disease affects several thousand men in the US and millions worldwide. At present there is no pharmacological treatment to prevent the onset of priapism in these patients, in part because the mechanisms involved in the development of priapism are complex and not well understood. Our group has established that a family of pentapeptides called opiorphins play a role in the development of priapism. Our most recent work has discovered that opiorphins are up-regulated in corporal smooth tissue in response to hypoxia and that opiorphins then regulate expression of genes that function in smooth muscle "relaxant" pathways. This has led us to propose the following hypothesis: Sickle cell disease causes hypoxia/ischemia in corporal tissue which results in increased opiorphin expression. Opiorphin then acts as a master regulator of compensatory smooth muscle "relaxant" pathways. The excessive activation of these "relaxant" pathways in corporal tissue is generally considered to lead to priapism. Our hypothesis will be tested in three Specific Aims. In Specific Aim 1 we will determine if opiorphin expression is increased in response to hypoxia in mouse and human cells in vitro and if up-regulation of opiorphin expression in turn activates pathways involved in corporal smooth muscle relaxation. We will confirm that the in vitro response to hypoxia correlates to similar changes in relaxant pathways in an in vivo corporal mouse model of hypoxia and if in this animal model there is heightened relaxation of corporal smooth muscle strips in organ bath studies. In Specific Aim 2 we will focus on a mouse model of sickle cell disease and determine if up-regulation of opiorphin expression in corporal tissue is an early event in sickle cell disease. We will determine in the sickle cell mouse corporal tissue if a similar set of genes involved in relaxant pathways are activated as in models of hypoxia (identified in Specific Aim 1). We will correlate changes in the genes involved in relaxant pathways with increased erectile tendencies and heighted relaxation of corporal smooth muscle tissue. In addition, we will determine changes in gene expression in a chemically-(blebbistatin)-induced mouse model of priapism. Analysis of the blebbistatin mouse model will distinguish genes that are changed "secondary" (ie. in response to priapism) rather than "causative" of priapism. In a clinical study we will compare the expression of opiorphin in the blood of sickle cell and non-sickle cell patients, and determine if opiorphin levels are increased during, or predictive of, a priapic-crisis. In Specific Aim 3 will develop opiorphin over expression or knock-down mouse models to directly demonstrate that opiorphins play a role in priapism/erectile function. These studies will utilize a novel delivery system developed by Dr. Joel Friedmans (Co-I) at Einstein- a paramagnetic nanoparticle carrying opiorphin-siRNA which can be targeted to the penis. We will use this system to specifically knock-down expression of opiorphin in the corporal tissue of sickle cell mice and determine if knock-down of opiorphin expression results in decreased erectile tendencies or decreased activity of smooth muscle relaxant pathways. If evidence confirms that knock-down of opiorphin reduces priapic-like activity in this animal model it would provide "proof-of-principle" to support this approach, or other strategies targeting opiorphin, to prevent priapism in sickle cell patients.

 描述（由申请人提供）：与镰状细胞病相关的阴茎异常勃起影响美国数千名男性和全球数百万男性。目前，还没有药物治疗可以预防这些患者出现阴茎异常勃起，部分原因是阴茎异常勃起的发生机制很复杂，而且还不清楚。我们的研究小组已经确定，一个名为阿片肽的五肽家族在阴茎异常勃起的发展中发挥作用。我们最近的工作发现，阿片类药物在低氧时在身体平滑肌组织中上调，然后阿片类药物调节在平滑肌“松弛”途径中起作用的基因的表达。这使我们提出了以下假设：镰状细胞病导致身体组织缺氧/缺血，导致阿片肽表达增加。然后，阿片肽充当补偿性平滑肌“松弛剂”途径的主要调节剂。这些“松弛”途径在身体组织中的过度激活通常被认为是导致阴茎异常勃起。 我们的假设将在三个具体目标中得到检验。在具体目标1中，我们将确定在体外小鼠和人细胞中，阿片肽表达是否响应于缺氧而增加，以及阿片肽表达的上调是否反过来激活参与躯体平滑肌松弛的途径。我们将证实，在体外对缺氧的反应相关的松弛剂途径在体内下士缺氧小鼠模型中的类似变化，如果在这种动物模型中，有提高器官浴研究中的下士平滑肌条的松弛。在具体目标2中，我们将重点关注镰状细胞病的小鼠模型，并确定在身体组织中阿片肽表达的上调是否是镰状细胞病的早期事件。我们将确定在镰状细胞小鼠的身体组织中，是否有一组类似的参与松弛剂途径的基因被激活，如在缺氧模型中（在特定目标1中确定）。我们将把松弛剂通路相关基因的变化与勃起倾向的增加和增强的身体平滑肌组织松弛联系起来。此外，我们将确定化学（blebbistatin）诱导的小鼠阴茎异常勃起模型中基因表达的变化。对blebbistatin小鼠模型的分析将区分“次级”改变的基因（即，响应于阴茎异常勃起）而不是阴茎异常勃起的“病因”。在临床研究中，我们将比较镰状细胞和非镰状细胞患者血液中阿片肽的表达，并确定阿片肽水平是否在阴茎勃起危象期间增加或预测阴茎勃起危象。在具体目标3将开发阿片肽超过 表达或敲除小鼠模型，以直接证明阿片肽在阴茎异常勃起/勃起功能中起作用。这些研究将利用Einstein的Joel Friedmans博士（Co-I）开发的一种新型递送系统-一种携带阿片肽siRNA的顺磁性纳米颗粒，可靶向阴茎。我们将使用该系统来特异性地敲低镰状细胞小鼠的身体组织中的阿片肽表达，并确定敲低阿片肽表达是否导致勃起倾向降低或平滑肌松弛剂途径的活性降低。如果有证据证实敲低阿片肽降低了该动物模型中的阴茎异常勃起样活性，则将提供“原理证明”来支持这种方法或靶向阿片肽的其他策略，以预防镰状细胞患者的阴茎异常勃起。