Role of neuraminidase activity on endothelial dysfunction in type 2 diabetes

项目摘要/摘要 内皮功能障碍与心血管疾病(CVD)的发展密切相关，心血管疾病是主要的 2型糖尿病(T2D)患者的死因。血管内皮细胞调节动脉直径和 通过产生包括一氧化氮(NO)在内的多种血管活性物质来维持血管的动态平衡。不是 是一种强大的血管扩张剂，是对血流诱导的剪应力的反应，通过 机械敏感型内皮腔结构。糖萼就是这样一种机械传感器。它由一个 相互交织的糖蛋白和蛋白多糖的网状物，当受到剪切力的干扰时，转化为 机械力转化为生化信号。这一过程的适当结果称为 机械转导，是血管内皮细胞依赖的血流介导的扩张(FMD)，被认为是金黄色的血管。 内皮功能的标准生理测量。值得注意的是，FMD受损在T2D和T2D中非常普遍 也是导致心血管疾病的机制的关键组成部分。然而，尽管扮演着主要角色 FMD减少在T2D相关CVD的发生中起作用，这是导致这种异常的机制 人们对此的反应尚不完全清楚。此外，目前还没有具体的治疗手段来缓解 FMD受损。这项提议的一个中心目标是破译导致脑功能损害的机制 并发现新的治疗靶点以改善其功能。基于我们以前的工作和最新的 令人兴奋的初步数据，我们提出了新的假设，即增加血浆神经氨酸酶活性 通过激活ADAM17(一种去整合素和金属蛋白酶-17)降解糖萼结构和 促进T2D患者的内皮功能障碍。我们将用功能的得失来检验我们的创新假说 人内皮细胞培养及分离的药理和遗传操作实验 在神经氨酸酶消融和T2D的动物模型中，以及在T2D的患者中。具体来说，在目标1中， 利用培养的人血管内皮细胞和分离的动脉，我们将确定 神经氨酸酶活性增加血管内皮细胞ADAM17活性，损害FMD。随后，在目标2中， 我们将在动物模型和患者中确定神经氨酸酶抑制对内皮功能的影响 使用T2D。我们假设，在T2D小鼠或人类中抑制神经氨酸酶可以改善FMD和整体 血管功能。我们的团队正准备通过一个项目来推动心血管和糖尿病的研究 这将对概念上新颖的多个层面的调查产生持续、强大的影响， 从机制上、方法论上和治疗上。事实上，以神经氨酸酶活性为目标 纠正T2D的内皮功能障碍并最终预防/治疗T2D的非凡前景- 相关的心血管疾病。

PROJECT SUMMARY/ABSTRACT Endothelial dysfunction is causally implicated in the development of cardiovascular disease (CVD), the main cause of death in patients with type 2 diabetes (T2D). The endothelium regulates arterial diameter and vascular homeostasis via the production of a myriad of vasoactive substances including nitric oxide (NO). NO is a powerful vasodilator produced in response to blood flow-induced shear stress, which is detected by mechanosensitive endothelial luminal structures. The glycocalyx is such a mechanosensor. It consists of a mesh of interwoven glycoproteins and proteoglycans that, when disturbed by shear stress, converts mechanical forces into biochemical signals. The appropriate result of this process, known as mechanotransduction, is endothelium-dependent flow-mediated dilation (FMD), which is considered the gold- standard physiological measure of endothelial function. Notably, impaired FMD is highly prevalent in T2D and also represents a critical component of the mechanisms that lead to CVD. However, despite the major role that reduced FMD plays in T2D-associated CVD development, the mechanisms that lead to this abnormal response are not completely known. In addition, there are currently no specific therapeutic means to alleviate impaired FMD. A central goal of this proposal is to decipher the mechanisms underlying the impairment of FMD in T2D and discover new therapeutic targets to improve it. Based on our prior work and most recent and exciting preliminary data, we propose the novel hypothesis that increased plasma neuraminidase activity degrades glycocalyx structures via activation of ADAM17 (a disintegrin and metalloproteinase-17) and promotes endothelial dysfunction in T2D. We will test our innovative hypothesis with gain- and loss-of-function pharmacological and genetic-manipulation experiments in human cultured endothelial cells and isolated arteries, in animal models of neuraminidase ablation and T2D, and in patients with T2D. Specifically, in Aim 1, using cultured endothelial cells and isolated arteries from humans, we will determine the mechanisms by which neuraminidase activity increases endothelial ADAM17 activation and impairs FMD. Subsequently, in Aim 2, we will determine the effects of neuraminidase inhibition on endothelial function in animal models and patients with T2D. We hypothesize that neuraminidase inhibition in T2D mice or humans improves FMD and overall vascular function. Our team is poised to move cardiovascular and diabetes research forward with a project that will exert a sustained, powerful impact across a number of levels of inquiry that are novel conceptually, mechanistically, methodologically, and therapeutically. Indeed, targeting neuraminidase activity holds extraordinary promise for correcting endothelial dysfunction in T2D and ultimately preventing/treating T2D- associated CVD.