Contribution of caveolin to diabetic vascular dysfunction

Caveolin 对糖尿病血管功能障碍的贡献

• 批准号: 7792788
• 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 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7792788
• 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

DESCRIPTION (provided by applicant): 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. PUBLIC HEALTH RELEVANCE: The incidence of diabetes that is associated with cardiovascular disease has more than doubled in the past 15 years. The objective of this proposal is to determine if the smooth muscle dysfunction underlying the pathology of diabetic vascular disease is related to a change in the localization of signaling molecules that determine the magnitude of smooth muscle contraction in diabetic blood vessels.

描述(由申请人提供)： 在过去的15年里，与心血管疾病相关的2型糖尿病的发病率增加了一倍多。其基础病理包括内皮和血管平滑肌(VSM)功能障碍，我们在两种不同的糖尿病小鼠模型中观察到这种功能障碍：瘦素受体缺陷(db/db)和链脲佐菌素诱导的糖尿病。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介导的血管扩张剂的松弛较少，对5-羟色胺和其他血管收缩因子的收缩更多，部分原因是Rho/Rho激酶途径的激活增加。尽管研究表明糖尿病患者的收缩功能增强，但这种异常的细胞机制尚不清楚。我研究的长期目标是了解糖尿病患者VSM功能障碍的细胞机制。血管收缩因子5-羟色胺能受体和RhoA被发现与小窝蛋白-1在VSM的特殊质膜微区相关。本实验室的研究表明，小窝蛋白-1(Cav-1)基因缺陷小鼠的主动脉收缩明显增加到5-羟色胺，而5-羟色胺可通过Rho激酶抑制剂恢复正常。依赖Rho的收缩在糖尿病患者中也同样增加。我们的总体假设是，5-羟色胺受体及其下游信号分子定位于小窝内，处于不活跃状态。这种受体和RhoA在小窝中的隔离在糖尿病患者中减少，有助于VSM更大的激活和收缩。在这项研究中，我们将评估糖尿病对肺泡微区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-羟色胺受体亚型是否发生变化(链脲佐菌素诱导或瘦素受体缺陷)。最后，我们将确定特定受体亚型或其下游信号成分在小凹内表达的变化是否有助于糖尿病血管收缩的增强。为了验证这一假说，我们将解决以下特定目标：特定目的1：确定受体介导的Rho/Rho激酶通路的激活是否发生在血管平滑肌的腔隙微域中。我们的工作假设是，激活Rho/Rho激酶途径的受体被隔离在小窝中。我们将评估基础和刺激条件下野生型和小窝蛋白-1缺陷小鼠的主动脉腔泡微域中特异性5-羟色胺受体、RhoA和Rho激酶的表达和定位。特异性目的2：探讨糖尿病时VSM空泡复合体的改变是否通过Rho/Rho激酶途径增加受体信号。我们的工作假设是，5-羟色胺受体和/或RhoA在腔泡微区的定位抑制了它们的激活，而这种激活在糖尿病患者中会减少。我们将比较基础和刺激条件下非糖尿病和糖尿病野生型或Cav-1缺陷的主动脉中5-羟色胺受体、RhoA和Rho激酶的表达与Cav-1的相关性。具体目的3：确定糖尿病血管功能障碍是否与5-羟色胺受体或RhoA的小窝蛋白-1区划改变有关。我们的工作假设是，小窝蛋白-1的缺失将增强受体介导的RhoA激活，这在糖尿病动脉中是增加的。我们将比较病毒转染法抑制(SiRNA)或过表达小窝蛋白-1对非糖尿病和糖尿病小鼠血管对特定5-羟色胺受体激动剂或直接激活RhoA的影响。 公共卫生相关性： 与心血管疾病相关的糖尿病发病率在过去15年中增加了一倍多。这一建议的目的是确定糖尿病血管疾病的病理基础的平滑肌功能障碍是否与决定糖尿病血管中平滑肌收缩幅度的信号分子的定位改变有关。