Influence of high glucose on endothelial function

描述（由申请人提供）：识别和干预直接导致血管并发症的分子通路将对预防血管并发症产生重大临床影响。 胰岛素依赖型糖尿病（IDDM）相关血管并发症。我们推测，由持续高血糖介导的内皮源性舒张因子（一氧化氮）信号通路改变导致的生理修复机制受损是血管并发症的原因。在正常生理条件下，热休克蛋白（Hsp-86）与内皮型一氧化氮合酶（NOS III）的相互作用负责一氧化氮依赖性内皮功能。然而，在高葡萄糖条件下，存在增强的抑制剂kB激酶活性（IKK-2），其竞争NOSIII与Hsp-86的结合。进一步的IKK-2结合使Hsp-86磷酸化。这一系列事件导致Hsp-86对NOS III的可用性不足，这降低了NOS III活性，最终结果是整联蛋白-粘着斑解体、延迟的内皮迁移和不良的血管修复。阻断IKK-2与遗传或药理学抑制剂结合药物，这是已经在临床实践中，可能会打开新的途径，以改善一氧化氮的生产和减少血管损伤的IDDM患者。拟议的研究构成了创新的方法，使用哺乳动物主动脉内皮细胞的体外细胞培养为基础的测定。使用遗传诱导的糖尿病动物模型和优化的动脉损伤程序进一步补充了体外机制方法。具体目的是：目的1将研究在高糖影响下NOS III和IKK-2与Hsp-86之间的竞争性串扰。将评价连续改变的一氧化氮信号传导途径对内皮迁移的影响。目的2将在体内确定1型小鼠模型中Hsp-86 - IKK-2串扰在NOS III失调中的贡献。目的3探讨IKK-2单用或与L-精氨酸联合应用在改善动脉损伤后内皮修复机制中的作用。所获得的知识将有助于确定新的途径，将改善目前的治疗方式，旨在预防或尽量减少血管并发症的严重程度的胰岛素依赖型糖尿病患者。

DESCRIPTION (provided by applicant): Identifying and intervening molecular pathways that directly contribute to vascular complications will have a significant clinical impact in preventing insulin dependent diabetes mellitus (IDDM)-associated vascular complications. We hypothesize that impaired physiological repair mechanisms due to altered endothelium- derived relaxation factor (nitric oxide) signaling pathway mediated by sustained high glucose is responsible for vascular complications. Under normal physiological condition, interaction of heat shock protein (Hsp-86) with endothelial nitric oxide synthase (NOS III) is responsible for nitric oxide-dependent endothelial functions. However, under high glucose condition, there is an enhanced inhibitor kB kinase activity (IKK-2), which competes out NOS lll from binding to Hsp-86. Further IKK-2 binding phosphorylates Hsp-86. This sequence of events lead to inadequate availability of Hsp-86 to NOS III, which decelerates NOS lll activity with a final outcome of integrin-focal adhesion disassembly, delayed endothelial migration and poor vascular repair. Blocking IKK-2 with genetic or pharmacological inhibitors in combination with agents, which are already in clinical practice, may open new avenues to improve nitric oxide production and reduce vascular damage in IDDM patients. The proposed study constitutes innovative approaches with the use of in vitro cell culture based assays using mammalian aortic endothelial cells. Use of genetically-induced diabetic animal model and optimized arterial injury procedures further complement the in vitro mechanistic approach. The specific aims are: Aim 1 will investigate the competitive cross talk between NOS III and IKK-2 with Hsp-86 under the influence of high glucose. The effect of sequentially altered nitric oxide signaling pathway on endothelial migration will be evaluated. Aim 2 will determine in vivo, the contribution of Hsp-86 - IKK-2 cross talk in NOS lll dysregulation in Type-1 mouse model. Aim 3 will evaluate the potentials of blocking IKK-2 independently or in combination with L-arginine in improving endothelial repair mechanism in response to arterial injury. The knowledge gained will help to identify new avenues that will improve the current treatment modalities aimed to prevent or minimize the severity of vascular complications of IDDM patients.