The role of the endothelial NPYR1-TRPC3-ET1 signaling axis in neurovascular coupling dysfunction

该R 01应用程序侧重于神经血管耦合功能障碍的潜在机制。大脑 消耗大量的能量，这些能量必须通过血流以氧气和葡萄糖的形式提供。神经血管 耦合是一种将局部神经元活动与血流相匹配的机制，对于维持局部神经元活动至关重要。 微环境和正常的大脑功能。然而，正常的神经血管耦合在癫痫发作中被破坏， 创伤性脑损伤和其他神经系统疾病。尽管神经元代谢持续高，但小 脑动脉和小动脉开始不适当地收缩以限制CBF到达受攻击的神经元。这 致病性血管收缩，称为“逆血流动力学反应”（IHR），被认为有助于 这些神经系统疾病的脑损伤和功能障碍。《国际卫生条例》的机制尚不清楚。 该提议旨在验证一个新的假设，即糖尿病诱导的IHR是由内皮细胞信号转导介导的。 神经肽Y受体1（NPYR 1）、瞬时受体电位（经典）3（TRPC 3） 通道和内皮素1（ET 1）。我们构建了可诱导的脑特异性内皮TRPC 3敲除细胞系， 和NPYR 1敲除系。这些新的小鼠系将与NPYR 1、TRPC 3和ET 1组合使用 受体选择性抑制剂来验证我们的假设目的1将证明存在内皮细胞 利用急性离体脑介导脑血管收缩的NPYR 1-TRPC 3-ET 1信号通路 实质小动脉和颅窗制备体内。目标2将表明， 信号通路介导顺铂诱导的IHR。目的3将确定是否中断这一信号通路将 降低癫痫发作的易感性及其有害后果。这些研究依赖于互补领域 由一个在脑血管反应性、癫痫和 神经炎症和神经变性。总的来说，这些实验将揭示新的机制 这可能会导致癫痫和其他神经系统疾病的新疗法。

This R01 application focuses on the underlying mechanisms of neurovascular coupling dysfunction. The brain consumes a large amount of energy which must be supplied as oxygen and glucose by blood flow. Neurovascular coupling, a mechanism that matches local neuronal activity to blood flow, is critical to maintain local microenvironment and normal brain function. However, normal neurovascular coupling is disrupted in seizure, traumatic brain injury, and other neurological disorders. Despite continued high neuronal metabolism, small cerebral arteries and arterioles begin to inappropriately constrict to limit CBF to the challenged neurons. This pathogenic vasoconstriction, termed the “inverse hemodynamic response” (IHR), is thought to contribute to brain damage and functional impairment in these neurological diseases. The mechanism of IHR is unknown. This proposal seeks to test a novel hypothesis that seizure-induced IHR is mediated by an endothelial signaling pathway consisted of Neuropeptide Y Receptor 1 (NPYR1), Transient Receptor Potential (Canonical) 3 (TRPC3) channels, and endothelin 1 (ET1). We generated inducible and brain-specific endothelial TRPC3 knockout line and NPYR1 knockout line. These novel mouse lines will be used in combination with NPYR1, TRPC3 and ET1 receptor selective inhibitors to test our hypothesis. Aim 1 will demonstrate the existence of an endothelial NPYR1-TRPC3-ET1 signaling pathway that mediates cerebral vasoconstriction using acutely isolated brain parenchymal arterioles and cranial window preparations in vivo. Aim 2 will show that the same signaling pathway mediates seizure-induced IHR. Aim 3 will determine whether disruption of this signaling pathway will reduce susceptibility to seizures and their deleterious consequences. The studies rely on complementary areas of expertise pooled by a research team with expertise in cerebrovascular reactivity, epilepsy and neuroinflammation and neurodegeneration. Collectively, these experiments will reveal new mechanistic insights regarding IHR and may lead to new treatments for epilepsy and other neurological diseases.