KRIT1 in Vascular Development and Dysfunction

KRIT1 在血管发育和功能障碍中的作用

基本信息

批准号：
8160349
负责人：
KEVIN J WHITEHEAD
金额：
$ 32.7万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-01 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8160349
关键词：
Abnormal Cell Abnormal Endothelial Cell Accounting Address Affect Alleles Animal Model Apical Apoptosis Biological Assay Biological Markers Biomechanics Birth Blood Vessels Blood flow Brain Brain hemorrhage CCM1 gene CDC42 gene Caliber Cavernous Malformation Cell Communication Cell Culture Techniques Cell Line Cell Polarity Cell Size Cell model Cells Cellular Stress Cellular biology Cerebrum Cessation of life Clinical Clinical Treatment Controlled Environment Cytoskeleton Defect Development Disease Disease Marker Disease Outcome Disease Progression Effectiveness Embryo Endothelial Cells Endothelium Excision Family Functional disorder Gene Targeting Genes Genetic Guanosine Triphosphate Phosphohydrolases Hemorrhage Hispanics Histologic Human Individual Inherited Intercellular Junctions Knock-out Lesion Life Longitudinal Studies Loss of Heterozygosity MAP Kinase Gene Magnetic Resonance Imaging Measures Medical Modeling Morphogenesis Morphology Mus Mutation Natural History Neuraxis New Mexico Observational Study Operative Surgical Procedures Outcome Pathogenesis Pathologic Pathway interactions Patient observation Patients Penetrance Permeability Pharmaceutical Preparations Physiological Physiology Population Prevention Proteins Relative (related person)Reporting Retinal Rho-associated kinase Risk Role Rupture Seizures Shapes Signal Pathway Signal Transduction Small Interfering RNA Southwestern United States Specimen Staging Stress Stress Fibers Stroke Syndrome System Tamoxifen Telangiectasis Testing Tissues Vascular Diseases Vascular Permeabilities Work angiogenesis cell motility disorder control efficacy testing fluid flow in vivo inhibitor/antagonist insight malformation monolayer mouse model mutant neurosurgery outcome forecast preclinical study research study response rho shear stress tool

项目摘要

DESCRIPTION (provided by applicant): Cerebral Cavernous Malformations (CCM) are common vascular lesions of the central nervous system found in 1 in 200 people. Lesions consist of thin-walled enlarged vascular spaces prone to rupture leading to hemorrhagic strokes, seizures, and death. The disease can be hereditary, in which case affected individuals tend to have multiple lesions, placing them at even greater risk. A large population with hereditary CCM disease is found in New Mexico and the Southwestern United States in which the disease is caused by mutations in the gene, KRIT1. At present, treatment of the disease consists of choosing between neurosurgery to remove lesions, or conservative "watchful waiting". Meaningful medical treatment of the disease will require an understanding of the underlying disease mechanisms, and will be greatly aided by animal models for use in pre-clinical trials of treatment. Recent studies have suggested a potential role for increased RhoA GTPase activity in the pathogenesis of the disease. The Ras family GTPases including RhoA, Rac1, and CDC42 regulate the cellular cytoskeleton, cell-cell interactions, and are involved in the cellular response to biomechanical stress. Other reports have suggested the importance of KRIT1 - Rap1 interactions in regulating cell junction proteins and endothelial cell apical - basal polarity. We hypothesize that KRIT1 is an important component of a mechanosensory apparatus that controls RhoA signaling with downstream effects on endothelial polarity. In this project we propose to use cell biology with physiologic levels of shear stress, and a newly developed animal model of CCM disease in mice to explore the role of KRIT1 in RhoA activation and cell polarity in vascular development and disease. We will describe the response of KRIT1 deficient endothelial cells when exposed to flow, as in living blood vessels, and study the response of signaling pathways in these cells. Using conditional gene targeting we will confirm that the underlying defect is found in the endothelial cells that line the CCM lesions. We will use an endothelial specific, drug inducible Cre system to knockout Krit1 from mice at birth. We have found that this approach leads to CCM lesions that can be seen and followed by MRI. We will use this system to test the efficacy of proposed treatments of CCM. In all of these aims we will evaluate the relative importance of RhoA activation and abnormal cell polarity. Further, we will develop and characterize non-invasive biomarkers of disease activity in CCM lesions, using the exaggerated progression of disease in this model and the access to tissue for mechanistic analysis to full advantage. PUBLIC HEALTH RELEVANCE: Cerebral Cavernous Malformations (CCM) are common vascular lesions of the brain that predispose to hemorrhagic stroke, seizures, and death. Mutations in KRIT1 are the most common genetic cause for CCM, and affect a large population of the original Hispanic settlers of the southwestern United States. This project will develop and characterize mouse and cellular models of CCM due to KRIT1 mutations to test potential therapies, validate surrogate clinical findings, and understand disease mechanisms in the hopes of transforming therapy from surgical removal to medical stabilization.

描述（由申请人提供）：脑海绵状血管瘤 (CCM) 是中枢神经系统常见的血管病变，每 200 人中就有 1 人患有脑海绵状血管瘤。病变由薄壁扩大的血管空间组成，容易破裂，导致出血性中风、癫痫发作和死亡。这种疾病可能是遗传性的，在这种情况下，受影响的个体往往有多处病变，使他们面临更大的风险。新墨西哥州和美国西南部发现了大量患有遗传性 CCM 疾病的人群，该疾病是由 KRIT1 基因突变引起的。目前，对该疾病的治疗包括选择神经外科手术切除病变，或保守的“观察等待”。对这种疾病进行有意义的医学治疗需要了解潜在的疾病机制，并且在临床前治疗试验中使用的动物模型将大大有助于该疾病的治疗。最近的研究表明 RhoA GTP 酶活性增加在该疾病的发病机制中具有潜在作用。 Ras 家族 GTPases 包括 RhoA、Rac1 和 CDC42，调节细胞骨架、细胞间相互作用，并参与细胞对生物力学应激的反应。其他报告表明 KRIT1 - Rap1 相互作用在调节细胞连接蛋白和内皮细胞顶端 - 基底极性中的重要性。我们假设 KRIT1 是机械感觉装置的重要组成部分，该装置控制 RhoA 信号传导并对内皮极性产生下游影响。在这个项目中，我们建议利用具有生理剪应力水平的细胞生物学以及新开发的小鼠 CCM 疾病动物模型来探索 KRIT1 在 RhoA 激活和细胞极性在血管发育和疾病中的作用。我们将描述 KRIT1 缺陷的内皮细胞在暴露于流动时（如在活血管中）的反应，并研究这些细胞中信号通路的反应。使用条件基因靶向，我们将确认在 CCM 病变排列的内皮细胞中发现了潜在的缺陷。我们将使用内皮特异性药物诱导 Cre 系统在小鼠出生时敲除 Krit1。我们发现这种方法会导致 CCM 病变，MRI 可以看到并跟踪这些病变。我们将使用该系统来测试所提出的 CCM 治疗方法的疗效。在所有这些目标中，我们将评估 RhoA 激活和异常细胞极性的相对重要性。此外，我们将利用该模型中夸大的疾病进展以及充分利用组织进行机械分析，开发和表征 CCM 病变中疾病活动的非侵入性生物标志物。公共卫生相关性：脑海绵状血管瘤 (CCM) 是常见的大脑血管病变，容易导致出血性中风、癫痫发作和死亡。 KRIT1 突变是 CCM 最常见的遗传原因，影响美国西南部的大量西班牙裔原始定居者。该项目将开发和表征由 KRIT1 突变引起的 CCM 小鼠和细胞模型，以测试潜在的疗法、验证替代临床结果并了解疾病机制，以期将治疗从手术切除转变为医疗稳定。