Brain Pericyte and Amyloid-beta Peptide Interaction

脑周细胞和淀粉样蛋白-β 肽相互作用

• 批准号: 8539524
• 负责人: Donghui Zhu
• 金额: $ 13.75万
• 依托单位: NORTH CAROLINA AGRI & TECH ST UNIV
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8539524
• 关键词: Actins; Adhesions; Affect; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Angiopoietin-1; Biological Preservation; Blood - brain barrier anatomy; Blood Vessels; Blood capillaries; Brain; Cell Shape; Cell physiology; Cells; Cerebral Amyloid Angiopathy; Cerebrum; Clinical; Contractile Proteins; Cytoskeletal Modeling; Cytoskeletal Proteins; Cytoskeleton; Degenerative Disorder; Deposition; Development; Endothelial Cells; Endothelium; Figs - dietary; Future; Goals; Growth Factor; Hemostatic function; Imaging Techniques; Immune; In Vitro; Intervention; Investigation; Knowledge; Lead; Ligand Binding; Maintenance; Mediating; Microcirculation; Movement; Myosin ATPase; Pathogenesis; Pericytes; Permeability; Phagocytes; Pharmacologic Substance; Platelet-Derived Growth Factor beta Receptor; Play; Process; Proteins; Recruitment Activity; Regulation; Research; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Transduction; Signaling Molecule; Smooth Muscle Actin Staining Method; Stem cells; Structure; Symptoms; System; Testing; Tight Junctions; Toxic effect; Transforming Growth Factor beta; Vascular Endothelial Growth Factors; Western Blotting; capillary; improved; migration; monomer; neurovascular unit; protein expression; public health relevance

DESCRIPTION (provided by applicant): Pericytes are small cells located outside of brain microvessels between the endothelial cell layer and the parenchyma. As part of the neurovascular unit, pericytes have a substantial range of functions including contractile, immune, phagocytic and stem cell functions, in addition to contributing to blood-brain barrier (BBB) maintenance and hemostasis. One pathological hallmark of Alzheimer's disease (AD) is a compromised BBB characterized by significant reductions in pericytes on the exterior walls of endothelia. Pericyte coverage on endothelia is necessary for normal BBB functioning and the relationship between destruction of these cells and the development and progression of AD symptoms is currently not well understood. Understanding the significance of pericyte functioning in pathological conditions such as AD will lead to the development of future pharmaceutical interventions and improved treatment. The objective of this study is to understand the mechanisms and processes that lead to reduced coverage of pericytes on the endothelial wall and the resulting weakening of the BBB in degenerative conditions such as AD. Aim 1 is to determine if A¿ decreases PDGFR¿ and signaling molecules involved in pericyte-mediated BBB integrity regulation, leading to a compromised BBB in AD. If PDGFR¿ controls the recruitment of pericytes to vessel wall, then reduced expression of PDGFR¿ induced by A¿ will help explain the loss or impaired recruitment of pericytes outside the endothelial wall in AD. If TGF¿, VEGF, and angiopoietin-1/-2 maintain BBB tight junction and paracellular permeability, then decreased secretion of these molecules from pericytes by A¿ will reveal an additional unknown mechanism leading to the compromise and leaks of the BBB in AD. We will examine the expression and translocation of these molecules using RT-PCR, Western blot and quantitative imaging techniques. Aim 2 is to determine if A¿ alters contractile and cytoskeletal proteins, therefore decreasing mobility, adhesion, and migration ability of pericytes, leading to impaired recruitment of pericytes to endothelia. Pericyte movement to endothelial cells is pivotal in vascular development and maintenance. Given that cytoskeletal and contratile proteins play key roles in cell shape, contraction, mobility and BBB permeability regulation, then our investigation of these proteins' expression, including alpha-smooth muscle actin (¿ -SMA) and myosin, and related actin cytoskeletal reorganization in the presence of A¿ will indicate that fewer pericytes are recruited to endothelia. Using in vitro capillary-like structures, we will idenify the rate-limiting step and key-signaling molecules in pericyte adhesion and migration affected by A¿. The rate-limiting step would be the ideal target for therapies.

描述(申请人提供)：周细胞是位于脑微血管外内皮细胞层和实质之间的小细胞。周细胞作为神经血管单位的一部分，除了维持血脑屏障(BBB)和止血外，还具有收缩、免疫、吞噬和干细胞等多种功能。阿尔茨海默病(AD)的一个病理特征是血脑屏障受损，其特征是内皮细胞外壁周细胞显著减少。周细胞覆盖内皮细胞是正常血脑屏障功能所必需的，这些细胞的破坏与AD症状的发展和进展之间的关系目前还不清楚。了解周细胞功能在阿尔茨海默病等病理条件下的重要性，将有助于开发未来的药物干预措施和改进治疗。本研究的目的是了解在退行性疾病如阿尔茨海默病中导致周细胞在内皮细胞壁上的覆盖率降低以及由此导致的血脑屏障减弱的机制和过程。目的1是确定A是否减少PDGFR和参与周细胞介导的血脑屏障完整性调节的信号分子，从而导致AD患者血脑屏障受损。如果PDGFR控制周细胞向血管壁的募集，那么A诱导的PDGFR表达减少将有助于解释AD时内皮壁外周细胞的缺失或募集受损。 如果转化生长因子β、血管内皮生长因子和血管生成素-1/-2维持BBB紧密连接和细胞旁通透性，则Aβ减少周细胞分泌这些分子将揭示导致AD时BBB妥协和泄漏的另一个未知机制。我们将使用RT-PCR、Western印迹和定量成像技术来检测这些分子的表达和易位。目的2是确定A是否改变收缩和细胞骨架蛋白，从而降低周细胞的移动性、粘附性和迁移能力，导致周细胞向内皮细胞的募集受损。周细胞向内皮细胞运动在血管的发育和维持中起着关键作用。鉴于细胞骨架和收缩蛋白在细胞形态、收缩、流动性和血脑屏障通透性调节中起关键作用，我们对这些蛋白的表达，包括α-平滑肌肌动蛋白(α-SMA)和肌球蛋白，以及相关的肌动蛋白细胞骨架重组的研究将表明，较少的周细胞被招募到内皮细胞。利用体外毛细血管样结构，我们将鉴定Aβ影响周细胞黏附和迁移的限速步骤和关键信号分子。限速措施将是治疗的理想目标。