Endothelial Insulin Resistance, Inflammation and Vascular Function in Diabetes

描述（由申请人提供）：糖尿病患者的心血管疾病是一个紧迫的临床问题。内皮细胞对维持血管内环境稳定至关重要。内皮细胞表型的改变导致一氧化氮生物活性的丧失和通过NF：B增加的内皮炎性激活可能有助于糖尿病的动脉粥样硬化形成和临床血管事件。最近的实验研究表明，胰岛素信号通过PI 3 K-Akt通路有助于内皮细胞一氧化氮的产生。在动物模型中，这些信号传导机制的缺失会导致内皮胰岛素抵抗和血管功能受损。PKC 2的激活可能将糖尿病的代谢紊乱与内皮胰岛素抵抗和促炎性内皮表型联系起来。尽管内皮细胞表型改变具有潜在的临床意义，但很少有研究将这些实验结果应用于糖尿病患者。我们的初步数据表明，内皮炎症激活与血管功能障碍和糖尿病使用一种新的方法来收集和表征人类受试者的内皮细胞。 我们现在提出的假设，即改变内皮细胞表型有助于糖尿病患者的血管功能障碍。在目的1中，我们将描述内皮细胞胰岛素抵抗和炎症激活与血管功能障碍和糖尿病的关系。我们将在120例糖尿病患者和120例对照组中，将内皮胰岛素信号传导标志物（eNOS表达、胰岛素介导的eNOS磷酸化）和从人受试者中新鲜分离的内皮细胞中内皮炎性活化证据（I：2、p65、ICAM表达）与糖尿病的存在和内皮血管功能障碍的严重程度（血流介导的扩张、外周动脉张力测定和反应性充血）联系起来。在目标2中，我们将研究PKC 2激活和NF：2激活对不利的内皮表型和受损的血管功能的贡献。我们假设，内皮细胞胰岛素抵抗和炎症激活将逆转与选择性PKC 2抑制剂（LY 379196）或NF：2抑制剂（水杨酸钠）在体外治疗，支持炎症和PKC 2激活糖尿病患者的作用。在目标3中，我们将通过评估安慰剂或抗炎药物双水杨酯（NF：2激活抑制剂）治疗前后的血管功能和内皮细胞表型，获得40例糖尿病患者内皮细胞表型改变导致一氧化氮生物利用度受损的证据。我们希望这些研究将提高我们对糖尿病血管疾病发病机制的理解，这将与创新的治疗和预防疗法的产生有关。 公共卫生相关性：糖尿病是一个严重的和日益增长的公共卫生问题，影响全球超过1.7亿人，至少20%的60岁以上的人。糖尿病的心血管并发症，包括心肌梗死、心力衰竭、外周动脉疾病和中风，占糖尿病患者死亡总数的65%以上。该应用旨在提高对糖尿病患者血管损伤机制的理解，并导致新的预防和治疗策略的产生，以减少这一高危人群的心血管疾病负担。

DESCRIPTION (provided by applicant): Cardiovascular disease in patients with diabetes is a pressing clinical problem. The endothelium is vital to the maintenance of vascular homeostasis. Alteration of endothelial cell phenotype leading to loss of nitric oxide bioactivity and increased endothelial inflammatory activation via NF:B may contribute to atherogenesis and clinical vascular events in diabetes. Recent experimental studies indicate that insulin signaling through the PI3K-Akt pathway contributes to endothelial nitric oxide production. Abnormalities of these signaling mechanisms produce endothelial insulin resistance and impair vascular function in animal models. Activation of PKC2 may link the metabolic derangements of diabetes to endothelial insulin resistance and pro-inflammatory endothelial phenotype. Despite the potential clinical relevance of altered endothelial phenotype, few studies have translated these experimental findings to patients with diabetes. Our preliminary data show that endothelial inflammatory activation is associated with vascular dysfunction and diabetes using a novel method to collect and characterize endothelial cells from human subjects. We now propose to test the hypothesis that altered endothelial cell phenotype contributes to vascular dysfunction in patients with diabetes. In Aim 1, we will characterize the relation of endothelial cell insulin resistance and inflammatory activation to vascular dysfunction and diabetes mellitus in human subjects. We will relate markers of endothelial insulin signaling (eNOS expression, insulin-mediated eNOS phosphorylation) and evidence of endothelial inflammatory activation (I:2, p65, ICAM expression) in endothelial cells freshly isolated from human subjects to the presence of diabetes and to the severity of endothelial vasomotor dysfunction (flow-mediated dilation, peripheral arterial tonometry and reactive hyperemia) in 120 patients with diabetes and 120 control subjects. In Aim 2, we will investigate the contribution of PKC2 activation and NF:2 activation to adverse endothelial phenotype and impaired vascular function. We hypothesize that endothelial cell insulin resistance and inflammatory activation will be reversed with in vitro treatment with selective PKC2 inhibitor (LY379196) or an NF:2 inhibitor (sodium salicylate), supporting a role for inflammation and PKC2 activation in patients with diabetes. In Aim 3, we will gain evidence that altered endothelial cell phenotype contributes to impaired nitric oxide bioavailability in 40 patients with diabetes by assessing vascular function and endothelial phenotype before and after treatment with placebo or the anti-inflammatory drug salsalate, an inhibitor of NF:2 activation. We expect that these studies will improve our understanding of the pathogenesis of vascular disease in diabetes that will be relevant to the generation of innovative therapeutic and preventive therapies. PUBLIC HEALTH RELEVANCE: Diabetes is a critical and growing public health problem that affects over 170 million people worldwide and at least 20% of individuals over age 60. Cardiovascular complications of diabetes including myocardial infarction, heart failure, peripheral artery disease and stroke are responsible for more than 65% of all deaths in patients with diabetes. This applications aims to develop an improved understanding of the mechanisms of vascular injury in patients with diabetes and lead to the generation of new prevention and treatment strategies to reduce the burden of cardiovascular disease in this high risk group.