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 常染色体显性遗传性脑动脉病伴皮质下白质脑病（CADASIL）是一种 一种常见的小血管疾病（SVD），其特征是微血管功能障碍，导致缺血性 中风和血管性痴呆。CADASIL是由平滑型胶原蛋白表达的NOTCH 3基因突变引起的。 肌肉细胞（SMC），其与较大的脉管系统如动脉/小动脉相关，以及周细胞， 缠绕在毛细血管上。这些突变诱导细胞外受体聚集和复合物形成， 其他蛋白质包括基质金属蛋白酶抑制剂TIMP 3。因此，TIMP 3积聚在 微循环导致脑血流量（CBF）调节受损。TIMP 3积累的下游， 病理机制包括表皮生长因子受体（EGFR）抑制，导致 神经血管偶联（NVC）和ATP产生。虽然这种病理机制已经在其他研究中进行了研究， 尽管在血管细胞类型（内皮细胞和SMC）中，周细胞仍然研究不足。 周细胞是一个丰富的，高度异质性的人口，其中包括网状周细胞，显示快速 开/关收缩反应，并且通常驻留在1- 4级毛细血管上。最近的研究表明， 通道Kir6.1，与微血管域中的其他细胞相比，在周细胞中独特地高度表达。 该通道已被证明在CBF调节中高度相关，其中从低ATP激活通道， 导致周细胞超极化，随后血管舒张，以增强局部脑灌注，以满足能量 要求。由于CADASIL的早期表现为神经血管功能障碍，因此该建议侧重于补片 周细胞及其损伤。 我的初步数据显示，在CADASIL中，网状周细胞Kir6.1通道在基础条件下异常活跃， 表明通道活动失调。然而，需要对通道进行进一步表征， 阐明潜在的治疗目标。具体而言，TIMP 3和EGFR信号传导如何影响Kir6.1通道 活动该建议的第一个目的是使用双峰方法来表征Kir6.1信道特性， 在大脑网状周细胞中的功能和表达。第二个目标的目标是揭露 Kir6.1通道功能障碍的潜在机制，包括TIMP 3外源性应用和遗传 击倒。该目的还将采用通过EGFR配体HB-EGF的拯救技术来恢复Kir6.1通道， 功能，由于其在大脑周细胞中的突出表达，可能是恢复CBF失调的关键 在CADASIL。该提案的完成将填补涉及脑补片的文献中的一个重大空白 周细胞和毁灭性的脑血管疾病，CADASIL，目前还没有治愈和有限的 治疗方案。