The role of tissue nonspecific alkaline phosphatase in brain endothelial cell homeostasis

组织非特异性碱性磷酸酶在脑内皮细胞稳态中的作用

• 批准号: 10220574
• 负责人: Candice Brown
• 金额: $ 54.18万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10220574
• 关键词: Address; Age; Aging; Alkaline Phosphatase; Behavioral; Biology; Blood - brain barrier anatomy; Blood Preservation; Blood Vessels; Brain; Brain Diseases; Cell physiology; Cerebral Ischemia; Cerebrovascular Disorders; Cerebrum; Cre driver; Data; Disease; Endothelial Cells; Endothelium; Enzymes; Exhibits; Extravasation; Female; Foundations; Functional disorder; Gene Expression; Genetic; Health; Homeostasis; Human; Impairment; In Vitro; Injections; Injury; Ischemic Stroke; Knowledge; Label; Link; LoxP-flanked allele; Metabolism; Middle Cerebral Artery Occlusion; Minerals; Modeling; Molecular; Mus; Outcome; Pathologic; Pathway Analysis; Pathway interactions; Permeability; Pharmacology; Physiological; Recovery of Function; Regulation; Reperfusion Therapy; Rho-associated kinase; Role; Signal Pathway; Signal Transduction; Stroke; Structure; Testing; Therapeutic; Tissues; Tracer; Treatment Efficacy; age group; age related; aged; aging brain; aging population; artery occlusion; astrogliosis; behavioral outcome; blood-brain barrier permeabilization; bone; brain endothelial cell; brain health; cadherin 5; cerebral ischemic injury; cerebral microvasculature; cerebrovascular; conditional knockout; enzyme activity; experimental group; fasudil; human disease; human old age (65+); improved; in vivo; indexing; inhibitor/antagonist; injured; male; middle age; mouse model; multiphoton microscopy; nervous system disorder; neurovascular unit; new therapeutic target; normal aging; novel; post stroke; preservation; response; restoration; stroke outcome; therapeutic target; tool; translational impact

PROJECT SUMMARY The objective of this application is to determine how tissue nonspecific alkaline phosphatase (TNAP) enzymatic activity maintains cerebrovascular function within the neurovascular unit (NVU). Brain microvascular endothelial cells (BMECs) comprise the cerebral microvasculature and serve as the structural foundation of the blood-brain barrier (BBB) and. Increased permeability and diminished integrity of BMECs are two common mechanisms through which cerebrovascular function is compromised in human disease. TNAP is a highly enriched enzyme in cerebral microvessels whose function in brain BMECs is poorly understood. Our preliminary data demonstrate that TNAP activity stimulates a novel signaling mechanism which protects against the loss of cerebral microvascular integrity and permeability. These intriguing findings led us to propose the central hypothesis that TNAP maintains NVU homeostasis during cerebral ischemia by preserving BBB integrity. We will utilize mice with a VE-cadherin-Cre driven conditional deletion of TNAP in endothelial cells (VEcKO) and its wild type littermates to interrogate the role of TNAP in BMECs. We will compare responses in young (4-5 months) and aged (18-20 months) mice to assess the age-dependent effects of brain endothelial TNAP on indices of brain endothelial barrier permeability combined with vascular network analysis and functional behavioral outcomes. Aim 1 will elucidate the contribution of brain endothelial cell TNAP to NVU dysfunction in ischemic stroke in young mice. We will employ the transient middle artery occlusion model to assess quantitative differences in cerebrovascular outcomes and behavioral indices. Aim 2 will determine the impact of brain endothelial cell TNAP on age-dependent impairment of the NVU. This aim will assess the impact TNAP on BMEC function in aging and the putative age-dependent interactions in ischemic stroke. Aim 3 will determine how the TNAP-Rho associated kinase (ROCK) pathway regulates the barrier function and whether pharmacological inhibition of the ROCK pathway protects against the loss of barrier integrity and functional deficits associated ischemic stroke in both young and aged mice. Taken together, the studies in this proposal will delineate a novel mechanism through which brain endothelial cell TNAP enzyme activity preserves NVU function in ischemic stroke and improves functional recovery post-stroke. The overall results will contribute to our limited understanding of the basic biology of TNAP’s role at the BBB and its contribution to NVU homeostasis in human health and disease.

项目概要 本应用的目的是确定组织非特异性碱性磷酸酶 (TNAP) 的酶促作用 活性维持神经血管单元（NVU）内的脑血管功能。 细胞 (BMEC) 构成脑微血管系统，是血脑的结构基础 屏障（BBB）和 BMEC 的渗透性增加和完整性降低是两种常见机制。 TNAP 是一种高度富集的酶，在人类疾病中会损害脑血管功能。 我们的初步数据表明，大脑微血管中的 BMEC 功能尚不清楚。 TNAP 活性刺激了一种新的信号传导机制，可防止大脑功能丧失 这些有趣的发现使我们提出了一个中心假设： TNAP 通过保持 BBB 完整性来维持脑缺血期间 NVU 稳态。 内皮细胞 (VEcKO) 及其野生型中 VE-cadherin-Cre 驱动的 TNAP 条件性删除 同窝出生的小鼠询问 TNAP 在 BMEC 中的作用，我们将比较幼仔（4-5 个月）和幼仔的反应。 年龄（18-20 个月）小鼠以评估脑内皮 TNAP 对脑指数的年龄依赖性影响 内皮屏障通透性结合血管网络分析和功能行为结果。 目标 1 将阐明脑内皮细胞 TNAP 对缺血性卒中 NVU 功能障碍的影响 我们将采用短暂的中动脉闭塞模型来评估年轻小鼠的数量差异。 目标 2 将确定脑血管结果和行为指标 TNAP 的影响。 该目标将评估 TNAP 对衰老过程中 BMEC 功能的影响。 缺血性中风中假定的年龄依赖性相互作用将决定 TNAP-Rho 的作用。 相关激酶 (ROCK) 通路调节屏障功能以及是否药理学抑制 ROCK 通路可防止屏障完整性丧失和与缺血性中风相关的功能缺陷 总的来说，本提案中的研究将通过以下方式描绘出一种新的机制。 脑内皮细胞 TNAP 酶活性可保留缺血性中风中的 NVU 功能并改善 中风后的功能恢复总体结果将有助于我们对基本功能的有限理解。 TNAP 在 BBB 中的作用及其对人类健康和疾病中 NVU 稳态的贡献的生物学。