Decoding the Molecular and Cellular Mechanisms of Mutant KRAS-driven Brain Arteriovenous Malformations

解读突变 KRAS 驱动的脑动静脉畸形的分子和细胞机制

基本信息

批准号：
10446836
负责人：
Jason Fish
金额：
$ 67.2万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-01 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10446836
关键词：
Adult Affect Anatomy Angiogenic Factor Animal Disease Models Animal Model Arteries Behavioral Assay Biology Blood Vessels Blood capillaries Blood flow Brain Neoplasms Brain hemorrhage Caliber Cell Culture Techniques Cell Shape Cells Cellular Morphology Cellular biology Cerebral cortex Cessation of life Child Clinical Cognition Cognitive Cues Cultured Cells Cytoskeleton Data Development Diagnosis Disease Down-Regulation Endothelial Cells Endothelium Etiology Event Extracellular Matrix FDA approved Family history of Frequencies GTP Binding Gene Expression Gene Expression Profiling Genes Genetic Genetic Transcription Goals Guanosine Triphosphate Phosphohydrolases Hemorrhage Histologic Histology Homeostasis Human Hypertension Hypoxia Image Immunohistochemistry In Vitro Intervention KRAS2 gene Knowledge Label Lesion MEK inhibition MEKs Maintenance Medical Minority Mitogen-Activated Protein Kinases Modality Modeling Molecular Molecular Target Monomeric GTP-Binding Proteins Morbidity - disease rate Mosaicism Movement Mus Mutation Neuraxis Neurofibrillary Tangles Operative Surgical Procedures Pathogenesis Pathologic Pathway interactions Patient-Focused Outcomes Patients Pericytes Pharmaceutical Preparations Pharmacology Phenotype Pre-Clinical Model Process Publishing Radiation Resistance Risk Rupture Sampling Severity of illness Shunt Device Signal Transduction Smooth Muscle Myocytes Stress Stroke Testing Therapeutic Embolization Time Vascular Smooth Muscle Vascular remodeling Veins Zebrafish brain arteriovenous malformations cadherin 5 cell behavior design disability risk exome sequencing feeding functional disability hemodynamics high risk improved in vivo inhibitor insight malformation mutant neuron loss novel novel therapeutics optogenetics prevent recruit response sensor shear stress single-cell RNA sequencing surgical risk therapeutic target transcriptomics vascular bed young adult

项目摘要

SUMMARY Brain arteriovenous malformations (bAVMs) are composed of abnormal connections between arteries and veins that lack an intervening capillary network. As a result, high-pressure blood from feeding arteries shunts directly into veins. These vascular lesions become distended and highly remodeled, resulting in a tangle of enlarged blood vessels that are prone to rupture. Indeed, bAVMs are a leading cause of hemorrhagic stroke in children and young adults. All current treatment modalities for bAVMs, including surgery, embolization or radiation carry a significant risk of disability or death, and these options are not available for ~20% of bAVM patients due to excessive risk. Because of these complications, alternative medical strategies with lower morbidities such as targeted pharmacological therapies are desperately needed. However, we first need a clear understanding of the biology underlying bAVM development and maintenance. The majority of bAVMs occur sporadically without a family history of the disease. Using whole exome sequencing, we recently identified somatic, activating mutations in the KRAS gene, which encodes a GTPase that is involved in signal transduction. The identified mutations were confined to the endothelium and result in KRAS being locked in a GTP-bound ‘ON’ state. Notably, we have established mouse and zebrafish models of endothelial-specific expression of mutant KRAS, which have revealed the sufficiency for these genetic lesions to drive disease. We have gone on to demonstrate, through transcriptional profiling of cultured cells and in vivo studies in zebrafish expressing mutant KRAS, that many KRAS-induced molecular and cellular changes require MEK/ERK activity. Much remains to be learned regarding the etiology of sporadic bAVMs and our cell culture, mouse and zebrafish models will enable us to define the molecular, cellular and morphological changes that are involved in the initiation and maintenance of bAVMs. We will utilize our expertise in animal models of bAVMs, imaging, cell biology, signaling and single-cell RNA sequencing, to gain unprecedented insight into the bAVM disease process. This information will be leveraged for the design of pharmacological interventions to improve patient outcomes. Our proposal will: 1) define the threshold of KRAS mutant endothelial cells that can remodel vessels, 2) identify the vascular bed(s) that are susceptible to active KRAS expression, 3) determine how KRAS mutations impact hemodynamic signaling and bAVM progression, 4) uncover the cell-autonomous and non-cell autonomous mechanisms of mutant KRAS, and 4) determine the requirement for KRAS and MEK activation for bAVM maintenance in our pre-clinical models. Together, these studies will expand our understanding of bAVM pathogenesis and will assess whether inhibition of the KRAS/MEK pathway may be a viable therapeutic target to pursue in human patients with bAVM.

概括脑动静脉畸形 (bAVM) 由动脉和静脉之间的异常连接组成缺乏介入的毛细血管网络，因此，来自供血动脉的高压血液直接分流。这些血管病变变得扩张并高度重塑，导致扩大的缠结。事实上，脑动静脉畸形是儿童出血性中风的主要原因。目前所有治疗 bAVM 的方法，包括手术、栓塞或放射治疗。残疾或死亡的重大风险，并且由于以下原因，这些选择不适用于约 20% 的 bAVM 患者由于这些并发症，需要采用发病率较低的替代医疗策略，例如迫切需要靶向药物治疗。然而，我们首先需要清楚地了解。 bAVM 发展和维持的生物学基础大多数 bAVM 都是零星发生的，而没有发生。通过全外显子组测序，我们最近发现了该疾病的家族史。 KRAS 基因发生突变，该基因编码参与信号转导的 GTP 酶。突变仅限于内皮细胞，导致 KRAS 被锁定在 GTP 结合的“ON”状态。我们建立了突变型 KRAS 内皮特异性表达的小鼠和斑马鱼模型，我们已经揭示了这些基因损伤足以导致疾病。通过培养细胞的转录分析和表达突变型 KRAS 的斑马鱼的体内研究，许多 KRAS 诱导的分子和细胞变化需要 MEK/ERK 活性，还有很多需要了解的地方。关于散发性 bAVM 的病因学和我们的细胞培养，小鼠和斑马鱼模型将使我们能够定义参与启动和维持的分子、细胞和形态变化我们将利用我们在 bAVM 动物模型、成像、细胞生物学、信号传导和单细胞方面的专业知识。 RNA 测序，以获得对 bAVM 疾病过程的前所未有的了解。我们的建议将用于设计药物干预措施以改善患者的治疗结果。定义可重塑血管的 KRAS 突变内皮细胞的阈值，2) 识别血管床对活跃的 KRAS 表达敏感，3) 确定 KRAS 突变如何影响血流动力学信号传导和 bAVM 进展，4) 揭示细胞自主和非细胞自主机制突变的 KRAS，以及 4) 确定我们的 bAVM 维护所需的 KRAS 和 MEK 激活这些研究将共同扩展我们对 bAVM 发病机制的理解，并将扩大我们对 bAVM 发病机制的理解。评估 KRAS/MEK 通路的抑制是否可能成为人类可行的治疗靶点 bAVM 患者。