Role of neuraminidase activity on endothelial dysfunction in type 2 diabetes

项目总结/摘要 内皮功能障碍与心血管疾病（CVD）的发展有因果关系， 2型糖尿病（T2 D）患者的死亡原因。内皮调节动脉直径， 通过产生包括一氧化氮（NO）在内的大量血管活性物质来维持血管内稳态。没有 是一种强大的血管扩张剂，产生于血流诱导的剪切应力，这是检测到的 机械敏感的内皮管腔结构。糖萼就是这样一种机械传感器。它包括一个 交织在一起的糖蛋白和蛋白聚糖的网状结构，当受到剪切力的干扰时， 机械力转化为生化信号。此过程的适当结果，称为 机械转导，是内皮依赖性流动介导的扩张（FMD），这被认为是黄金， 内皮功能标准生理测量。值得注意的是，受损的FMD在T2 D中非常普遍， 也是导致CVD机制的关键组成部分。然而，尽管发挥了重要作用， 减少FMD在T2 D相关CVD发展中的作用，导致这种异常的机制 答案并不完全清楚。此外，目前尚无特效治疗手段缓解 FMD受损。这项建议的一个中心目标是破译损害的潜在机制， FMD在T2 D和发现新的治疗靶点，以改善它。根据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，增加血浆神经氨酸酶活性， 通过激活ADAM 17（一种去整合素和金属蛋白酶-17）降解糖萼结构， 促进T2 D中的内皮功能障碍。我们将通过功能的获得和丧失来检验我们的创新假设 在人培养的内皮细胞和分离的内皮细胞中的药理学和遗传操作实验 动脉，在神经氨酸酶消融和T2 D的动物模型中，以及在T2 D患者中。具体而言，在目标1中， 使用培养的内皮细胞和分离的人类动脉，我们将确定其机制， 神经氨酸酶活性增加内皮细胞ADAM 17活化并损害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剂对内皮功能的影响 关于T2 D我们假设T2 D小鼠或人类中的神经氨酸酶抑制剂改善了FMD， 血管功能我们的团队准备通过一个项目推动心血管和糖尿病研究的发展 这将在概念上新颖的多个层次的探究中产生持续的、强大的影响， 从机械学、方法学和治疗学的角度。事实上，靶向神经氨酸酶活性 纠正T2 D内皮功能障碍并最终预防/治疗T2 D的非凡前景- 相关CVD

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.