Pericyte KATP channel hyperactivity in cerebral small vessel disease

脑小血管疾病中周细胞 KATP 通道过度活跃

• 批准号: 10750246
• 负责人: Danielle A Jeffrey
• 金额: $ 3.91万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-16 至 2026-07-15
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750246
• 关键词: 3-Dimensional; Acute; Agonist; Arterial Disorder; Arteries; Blood Vessels; Blood capillaries; Brain; Capillary Endothelial Cell; Cells; Cephalic; Cerebral small vessel disease; Cerebrovascular Circulation; Cerebrovascular Disorders; Cerebrum; Chronic; Complex; Computer software; DTR gene; Data; Dementia; Deposition; Diameter; Disease; Distal; Endothelial Cells; Epidermal Growth Factor Receptor; Exposure to; Extracellular Domain; Functional disorder; Genetic; Glyburide; Goals; Hour; Hyperactivity; Image; Immunohistochemistry; Impairment; Induced Mutation; Ischemic Stroke; Kinetics; Ligands; Link; Literature; Location; Matrix Metalloproteinase Inhibitor; Measures; Membrane Potentials; Metabolic; Metabolic Diseases; Microcirculation; Microvascular Dysfunction; Modality; Modeling; Morphology; Mus; Mutation; NOTCH3 gene; Nature; Neurons; Nutrient; Paper; Patients; Perfusion; Pericytes; Physiological; Pinacidil; Population; Potassium; Preparation; Production; Property; Proteins; Publishing; Reagent; Receptor Aggregation; Receptor Inhibition; Receptor Signaling; Regulation; Relaxation; Reporting; Role; Sentinel; Signal Transduction; Smooth Muscle Myocytes; Subcortical Infarctions; Subcortical Leukoencephalopathy; Syndrome; TIMP3 gene; Techniques; Testing; Thinness; Training; Vascular Dementia; Vascular Smooth Muscle; Vasodilation; antagonist; arteriole; autosome; cell type; comparison control; electrical property; experimental study; extracellular; genetic approach; in vivo; insight; knock-down; mouse model; mutant; neurovascular; neurovascular coupling; new therapeutic target; novel; parenchymal arterioles; patch clamp; receptor; response; two-photon; uK-ATP-1 potassium channel

Project Summary Cerebral Autosomal Dominate Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a common small vessel disease (SVD) that is characterized by microvascular dysfunction leading to ischemic stroke and vascular dementia. CADASIL is caused by mutations in the NOTCH3 gene expressed by smooth muscle cells (SMCs), that are associated with larger vasculature such as arteries/arterioles, and pericytes that wrap around capillaries. These mutations induce extracellular receptor aggregation and complex formation with other proteins including matrix metalloproteinase inhibitor, TIMP3. TIMP3 therefore accumulates around the microcirculation causing impaired cerebral blood flow (CBF) regulation. Downstream of TIMP3 accumulation, the pathomechanism includes epidermal growth factor receptor (EGFR) inhibition, resulting in decreased neurovascular coupling (NVC) and ATP production. While this pathomechanism has been investigated in other vascular cell types (endothelial cells and SMCs), pericytes remain understudied. Pericytes are an abundant, highly heterogenous population, that includes mesh pericytes which display fast on/off contractile responses and typically reside on 1-4th order capillaries. Recent studies have revealed a KATP channel, Kir6.1, is uniquely highly expressed in pericytes compared to other cells in the microvascular domain. This channel has proven to be highly relevant in CBF regulation where activation of the channel from low ATP, results in pericyte hyperpolarization, ensuing vasodilation to enhance regional cerebral perfusion to meet energy demands. Due to the CADASIL’s early presentation of neurovascular dysfunction, this proposal focuses on mesh pericytes and their impairment. My preliminary data show that, in CADASIL, mesh pericyte Kir6.1 channels are hyperactive in basal conditions, indicating dysregulation of channel activity. However further characterization of the channel is needed to elucidate potential treatment targets. Specifically, how TIMP3 and EGFR signaling influence Kir6.1 channel activity. This proposal’s first Aim is to characterize Kir6.1 channel properties using a bimodal approach looking at both function and expression in cerebral mesh pericytes. The goal of the second Aim is to expose the mechanism underlying Kir6.1 channel dysfunction including TIMP3 exogenous application and genetic knockdown. This Aim will also employ rescue techniques via EGFR ligand, HB-EGF, to restore Kir6.1 channel function, which due to its prominent expression in cerebral pericytes may be key to restoring CBF dysregulation in CADASIL. Completion of this proposal will fill a significant gap in the literature involving cerebral mesh pericytes and the devastating cerebrovascular disease, CADASIL which currently has no cure and limited treatment options.

项目摘要 脑常染色体统治动脉病，伴有皮质下肌和白细胞脑病（卡达西尔）是一个 具有微血管功能障碍的特征的常见小血管疾病（SVD）导致缺血性 中风和血管痴呆。卡达西尔是由平滑表达的Notch3基因突变引起的 肌肉细胞（SMC），与较大的脉管系统有关，例如动脉/动脉和周细胞 环绕毛细血管。这些突变引起细胞外接收器的聚集和复杂形成 其他蛋白质包括基质金属蛋白酶抑制剂Timp3。 Timp3因此围绕 微循环导致脑血流受损（CBF）调节。 Timp3积累的下游， 病理机制包括表皮生长因子受体（EGFR）抑制，导致下降 神经血管耦合（NVC）和ATP产生。虽然已经研究了这种病理机理 血管细胞类型（内皮细胞和SMC），周围的细胞细胞仍然了解。 周细胞是绝对的，高度异质的人群，包括快速显示的网状周细胞 开/关收缩响应，通常居住在1-4阶毛细管上。最近的研究揭示了Katp 与微血管结构域中的其他细胞相比，在周细胞中，通道（Kir6.1）在周细胞中具有唯一的高度表达。 事实证明，该通道在CBF调节中高度相关，在CBF调节中，从低ATP激活通道， 导致周细胞超极化，确保血管舒张增强区域脑灌注以满足能量 需求。由于卡达西尔早期表现出神经血管功能障碍，该提案重点介绍 周细胞及其障碍。 我的初步数据表明，在卡达西尔，网状周围Kir6.1通道在基本条件下过度活跃， 表明通道活性失调。但是，需要进一步的渠道表征 阐明潜在的治疗目标。具体而言，Timp3和EGFR信号如何影响Kir6.1通道 活动。该提案的第一个目的是使用双峰方法来表征Kir6.1频道属性 在脑网状周细胞中的功能和表达上。第二个目标的目标是公开 Kir6.1基础机制通道功能障碍，包括Timp3外源应用和遗传 击倒。此目标还将通过HB-EGF使用EGFR配体来恢复Kir6.1频道 功能，由于其在脑周细胞中的显着表达可能是恢复CBF失调的关键 在卡达西尔。该提案的完成将填补涉及脑网格的文献中的显着空白 周细胞和毁灭性的脑血管疾病，卡达西目前尚无治愈且有限 治疗选择。