Contribution of caveolin to diabetic vascular dysfunction

Caveolin 对糖尿病血管功能障碍的贡献

• 批准号: 8258649
• 负责人: KATHRYN G LAMPING
• 金额: --
• 依托单位: IOWA CITY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8258649
• 关键词: Address; Affect; Aorta; Arteries; Blood; Blood Vessels; CAV1 gene; Cardiovascular Diseases; Cardiovascular system; Caveolae; Caveolins; Cell membrane; Complex; Contracts; Data; Diabetes Mellitus; Diabetic Angiopathies; Diabetic mouse; Functional disorder; G-Protein-Coupled Receptors; Goals; Heart Diseases; Incidence; Laboratories; Mediating; Membrane Microdomains; Mus; Muscle Contraction; Non-Insulin-Dependent Diabetes Mellitus; Pathology; Pathway interactions; Peripheral Vascular Diseases; Proteins; Receptor Signaling; Research; Rho-associated kinase; Serotonin; Serotonin Agonists; Signal Pathway; Signal Transduction; Signaling Molecule; Small Interfering RNA; Smooth Muscle; Streptozocin; Stroke; Testing; Thromboxanes; Tissues; Transfection; Vascular Smooth Muscle; Vasoconstrictor Agents; Vasodilator Agents; Veterans; Viral; Wild Type Mouse; Work; base; caveolin 1; diabetic; inhibitor/antagonist; leptin receptor; mimetics; mouse model; non-diabetic; overexpression; public health relevance; receptor; response; rho; serotonin receptor; vasoconstriction

In the last 15 years, the incidence of Type 2 diabetes associated with cardiovascular disease has more than doubled. The underlying pathology includes both endothelial and vascular smooth muscle (VSM) dysfunction which we have observed in two different mouse models of diabetes: leptin receptor deficient (db/db) and streptozotocin-induced. Compared to non-diabetic mice, aorta from both diabetic mouse models relax less to endothelial NO-mediated vasodilators and contract more to serotonin and other vasoconstrictors, in part, mediated by increased activation of the rho/rho kinase pathway. Although studies have demonstrated increased contractile function in diabetes, the cellular mechanisms underlying this abnormality are unknown. The long-term goal of my research is to understand the cellular mechanisms that contribute to the dysfunction of VSM in diabetes. Vasoconstrictor serotonergic receptors and rhoA have been found associated with caveolin-1 in specialized plasma membrane microdomains of VSM. Studies in our laboratory demonstrate that contractions of aorta isolated from caveolin-1 (cav-1) gene deficient mice are markedly increased to serotonin which are restored to normal by inhibitors of rho kinase. Rho-dependent contractions are similarly increased in diabetes. Our overall hypothesis is that serotonin receptors and their downstream signaling molecules are localized within caveolae in an inactive state. This sequestering of receptors and rhoA in caveolae is reduced in diabetes contributing to greater activation and contraction of VSM. In this proposal we will assess the impact of diabetes on the expression of rhoA, rho kinase and serotonin receptors in caveolar microdomains. We will also determine if the subtype of serotonin receptors changes in VSM in diabetics (streptozotocin- induced or leptin receptor deficient). Finally, we will determine whether a change in the expression of specific receptor subtypes or their downstream signaling components within caveolae contributes to the enhanced vasoconstriction in diabetes. To test this hypothesis, we will address the following specific aims: SPECIFIC AIM 1: To establish if receptor-mediated activation of the rho/rho kinase pathway occurs in caveolar microdomains in vascular smooth muscle. Our working hypothesis is that receptors that activate the rho/rho kinase pathway are sequestered in caveolae. We will assess expression and localization of specific serotonin receptors, rhoA and rho kinase in caveolar microdomains in aorta from wild type and caveolin-1 deficient mice under basal and stimulated conditions. SPECIFIC AIM 2: To determine whether VSM caveolar complexes change in diabetes to increase receptor signaling through the rho/rho kinase pathway. Our working hypothesis is that localization of serotonin receptors and/or rhoA in caveolar microdomains suppresses their activation which is reduced in diabetes. We will compare expression of serotonin receptors, rhoA and rho kinase in association with cav-1 in lipid rafts in non-diabetic and diabetic wild type or cav-1 deficient aorta under basal and stimulated conditions. SPECIFIC AIM 3: To determine whether the vascular dysfunction in diabetes is related to a change in caveolin-1 compartmentalization of serotonin receptors or rhoA. Our working hypothesis is that deletion of caveolin-1 will augment receptor mediated rhoA activation and this is increased in diabetic arteries. We will compare the effects of inhibition (siRNA) or overexpression of caveolin-1 using viral transfection on vascular responses to specific serotonin receptor agonists or direct activation of rhoA in non-diabetic and diabetic mice.

在过去的15年里，与心血管疾病相关的2型糖尿病的发病率比其他疾病高。 比翻了一番。潜在的病理包括内皮和血管平滑肌（VSM） 我们在两种不同的糖尿病小鼠模型中观察到的功能障碍：瘦素受体缺陷 (db/db）和链脲霉素诱导的。与非糖尿病小鼠相比，两种糖尿病小鼠模型的主动脉 对内皮NO介导的血管舒张剂的舒张较少，而对5-羟色胺和其他血管收缩剂的收缩较多， 部分是由rho/rho激酶途径的激活增加介导的。尽管研究表明 糖尿病中的收缩功能增加，这种异常的细胞机制尚不清楚。 我研究的长期目标是了解导致功能障碍的细胞机制 VSM在糖尿病中的作用已经发现血管收缩剂肾上腺素能受体和rhoA与 小窝蛋白-1在VSM的专门质膜微域中的表达。我们实验室的研究表明， 从小窝蛋白-1（caveolin-1）基因缺陷小鼠分离的主动脉收缩对5-羟色胺显著增加 通过rho激酶抑制剂恢复正常。Rho依赖性收缩也同样增加， 糖尿病我们的总体假设是，血清素受体及其下游信号分子是 在非活动状态下位于小窝内。这种受体和rhoA在小窝中的隔离减少 在糖尿病中有助于VSM的更大激活和收缩。在本建议中，我们将评估 糖尿病对小窝微区rhoA、rho激酶和5-羟色胺受体表达的影响 我们还将确定糖尿病患者VSM中5-羟色胺受体的亚型是否发生变化（链脲佐菌素- 诱导的或瘦素受体缺陷的）。最后，我们将确定是否在特定的表达的变化， 小窝内的受体亚型或其下游信号传导组分有助于增强 糖尿病的血管收缩为了检验这一假设，我们将讨论以下具体目标： 具体目的1：确定受体介导的rho/rho激酶通路激活是否发生在小窝中。 血管平滑肌中的微区。我们的假设是激活rho/rho的受体 激酶途径被隔离在小窝中。我们将评估特定5-羟色胺的表达和定位 野生型和小窝蛋白-1缺陷小鼠主动脉小窝微区的受体、rhoA和rho激酶 在基础和刺激条件下。 具体目的2：确定糖尿病中VSM小窝复合体是否发生变化以增加受体 通过rho/rho激酶途径进行信号传导。我们的工作假设是， 小窝微结构域中的受体和/或rhoA抑制它们的活化，这在糖尿病中降低。我们 将比较血清素受体、rhoA和rho激酶与脂筏中cav-1的表达， 在基础和刺激条件下的非糖尿病和糖尿病野生型或CAV-1缺陷型主动脉。 具体目的3：确定糖尿病血管功能障碍是否与小窝蛋白-1的变化有关 血清素受体或rhoA的区室化。我们的工作假设是，caveolin-1的缺失将 增强受体介导的rhoA激活，这在糖尿病动脉中增加。我们将比较 使用病毒转染抑制（siRNA）或过度表达小窝蛋白-1对血管反应的影响 特异性5-羟色胺受体激动剂或直接激活非糖尿病和糖尿病小鼠中的rhoA。