Role of calcium sensitization in diabetes-induced erectile dysfunction

钙敏化在糖尿病引起的勃起功能障碍中的作用

• 批准号: 7316604
• 负责人: Michael Edward DiSanto
• 金额: $ 41.5万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-14 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7316604
• 关键词: Address; Adrenergic Agonists; Affect; Alloxan; Animals; Applications Grants; Attention; Attenuated; Bladder; Blood Vessels; Calcium; Cells; Class; Complex; Complications of Diabetes Mellitus; Condition; Corpora Cavernosa; Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Data; Diabetes Mellitus; Disease; Down-Regulation; Endothelin; Endothelin-1; Enzymes; Erectile dysfunction; Etiology; Failure; Genitourinary system; Glucose; Human; Insulin; Insulin-Dependent Diabetes Mellitus; Knowledge; Link; Maintenance; Mediating; Molecular; Molecular Target; Muscle relaxation phase; Myosin ATPase; Myosin Light Chain Kinase; Nitric Oxide; Non-Insulin-Dependent Diabetes Mellitus; Numbers; Operative Surgical Procedures; Oryctolagus cuniculus; Pathology; Pathway interactions; Patients; Penile Tumescence; Pharmaceutical Preparations; Phenylephrine; Phosphorylation; Physiological; Plasmids; Population; Prevalence; Process; Production; Protein Overexpression; Proteins; Rate; Rattus; Refractory; Regulation; Relaxation; Reporting; Research; Research Personnel; Rho-associated kinase; Role; Role playing therapy; Rosa; Signal Transduction Pathway; Smooth Muscle; Smooth Muscle Myocytes; Smooth Muscle Myosins; Specimen; Stimulus; Sum; System; Therapeutic; Translating; United States; base; desensitization; diabetic; diabetic rat; erection; gain of function; inhibitor/antagonist; insight; loss of function; men; myosin phosphatase; neurophysiology; novel; phosphodiesterase V; prevent; programs; response; satisfaction; sphingosine 1-phosphate; telokin; therapeutic target; type I and type II diabetes

DESCRIPTION (provided by applicant): It is estimated that, on average, 50% of the 10 million men with diabetes mellitus (DM) have erectile dysfunction (ED) with both Type 1 and Type 2 DM nearly equally associated with ED. Although efficacious orally active PDE5 inhibitors have been developed to treat ED, a large percentage of diabetic men (with estimates as high as 50%) remain refractory to this therapy. The specific hypothesis of this proposal is that an increased corpus cavernosum smooth muscle (CCSM) basal tone and inability to properly relax the CCSM in diabetes-induced ED is mediated by SM calcium sensitization via inhibition of smooth muscle myosin phosphatase (SMMP) activity. Specifically, to address this hypothesis, we will examine the expression and regulation of molecules that either directly or indirectly regulate SMMP activity and the roles that they play in "calcium sensitization/desensitization" pathways will be elucidated. Using CCSM from Type- I and Type II diabetic rats, patients with ED, as well as cultured CCSM cells, our hypothesis will be addressed by accomplishing the following specific aims: 1) To determine, using both Type I and Type II rat models of diabetes a) the precise correlation between diabetes and ED, b) whether there is an increased expression/activity of the "calcium-sensitizing" enzyme Rho-kinase, three well-established ROK regulators (RhoA, endothelin and sphingosine-1-phosphate) and/or the SMMP inhibitory protein CPI-17 in diabetic animals, and the correlation of these changes with ED and c) if there is a simultaneous downregulation of molecules that promote the "calcium desensitization" of smooth muscle (namely PKG-1 and telokin), 2) To determine a) whether similar alterations in the expression/activity of "calcium sensitization/desensitization"- associated molecules that occur in response to experimentally-induced diabetes can be induced in isolated CCSM cells (e.g. high glucose, high insulin, exogenous Et-1, etc.) and b) the ability of pharmacological inhibition of "calcium sensitization" molecules or plasmid-mediated overexpression of "calcium desensitization" molecules to prevent, attenuate or reverse ED and the mechanisms for these effects and 3) To determine, using human CCSM specimens routinely isolated from men undergoing penile surgery to treat ED, whether alterations in the "calcium sensitization/desensitization" pathways in the rat translate to diabetic humans with ED. The data obtained by the completion of the studies described above should provide keen and novel insight into the molecular mechanism for diabetes-induced ED and also establish which "calcium sensitization/desensitization" pathways may serve as attractive molecular therapeutic targets for the treatment of ED. Moreover, since similar changes in "calcium sensitization" pathways are beginning to emerge in diabetic vascular SM, knowledge gained from these studies may have implications in diabetes- induced pathologies beyond the urogenital system.

描述（由申请人提供）：据估计，平均而言，1000 万糖尿病 (DM) 男性中有 50% 患有勃起功能障碍 (ED)，其中 1 型和 2 型 DM 与 ED 的相关性几乎相同。尽管已经开发出有效的口服活性 PDE5 抑制剂来治疗 ED，但很大比例的糖尿病男性（估计高达 50%）仍然对这种疗法无效。该提议的具体假设是，糖尿病引起的 ED 中海绵体平滑肌 (CCSM) 基础张力增加和 CCSM 无法适当放松是由 SM 钙敏化通过抑制平滑肌肌球蛋白磷酸酶 (SMMP) 活性介导的。具体来说，为了解决这一假设，我们将检查直接或间接调节 SMMP 活性的分子的表达和调节，并阐明它们在“钙敏化/脱敏”途径中发挥的作用。使用来自 I 型和 II 型糖尿病大鼠、ED 患者的 CCSM 以及培养的 CCSM 细胞，我们的假设将通过实现以下具体目标来解决：1) 使用 I 型和 II 型大鼠模型来确定糖尿病 a) 糖尿病与 ED 之间的精确相关性，b) “钙敏化”酶 Rho 激酶（三种成熟的 ROK 调节因子（RhoA、内皮素和内皮素）的表达/活性是否增加1-磷酸鞘氨醇）和/或糖尿病动物中的 SMMP 抑制蛋白 CPI-17，以及这些变化与 ED 的相关性和 c）是否同时下调促进平滑肌“钙脱敏”的分子（即 PKG-1 和 telokin），2) 确定 a) 响应于“钙敏化/脱敏”相关分子的表达/活性是否发生类似的改变实验诱导的糖尿病可以在分离的 CCSM 细胞中诱导（例如高葡萄糖、高胰岛素、外源性 Et-1 等）和 b) 药物抑制“钙敏化”分子或质粒介导的“钙脱敏”过度表达的能力“预防、减轻或逆转 ED 的分子以及这些作用的机制，以及 3) 使用从接受阴茎手术治疗 ED 的男性中常规分离的人类 CCSM 标本来确定是否发生改变大鼠中的“钙敏化/脱敏”途径转化为患有 ED 的糖尿病人类。完成上述研究所获得的数据应该为糖尿病引起的 ED 的分子机制提供敏锐而新颖的见解，并确定哪些“钙敏化/脱敏”途径可以作为治疗 ED 的有吸引力的分子治疗靶点。此外，由于糖尿病血管 SM 中开始出现“钙敏化”途径的类似变化，因此从这些研究中获得的知识可能对泌尿生殖系统以外的糖尿病引起的病理有影响。