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：
10584546
负责人：
Jason Fish
金额：
$ 64.49万
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 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10584546
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 Cell Culture Techniques Cell Shape Cells Cellular biology Central Nervous System Cerebral cortex Cessation of life Child Clinical Cognition Cognitive Cues Cultured Cells Cytoskeleton Data Development Diagnosis Diameter 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 Learning Lesion MEK inhibition MEKs Maintenance Medical Minority Mitogen-Activated Protein Kinases Modality Modeling Molecular Molecular Target Monomeric GTP-Binding Proteins Morbidity - disease rate Morphology Movement Mus Mutation Neurofibrillary Tangles Operative Surgical Procedures Pathogenesis Pathologic Pathway interactions Patient-Focused Outcomes Patients Pericytes Pharmaceutical Preparations Phenotype Pre-Clinical Model Predisposition 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 mosaic mutant neuron loss novel novel therapeutics optogenetics pharmacologic 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.

概括脑动力畸形（BAVM）由动脉和静脉之间的异常连接组成缺乏中间的毛细管网络。结果，喂养动脉分流的高压血液直接血液变成静脉。这些血管病变变得膨胀并进行了高度重塑，导致缠结容易破裂的血管。确实，Bavms是儿童出血性中风的主要原因和年轻人。 BAVM的所有当前治疗方式，包括手术，栓塞或辐射携带残疾或死亡的重大风险，由于约20％的BAVM患者，这些选择不可用过多的风险。由于这些并发症，替代医疗策略具有较低的病毒性迫切需要有针对性的药物疗法。但是，我们首先需要清楚地了解 BAVM开发和维护的生物学。大多数Bavms偶尔出现该疾病的家族史。使用整个外显子组测序，我们最近确定了躯体，激活 KRAS基因中的突变，该突变编码与信号转导有关的GTPase。确定的突变仅限于内皮，导致Kras被锁定在GTP绑定的状态下。尤其，我们已经建立了突变kras内皮特异性表达的小鼠和斑马鱼模型，已经揭示了这些遗传病变驱动疾病的充分性。我们继续演示，通过培养细胞的转录分析和斑马鱼表达突变kras的体内研究，许多KRAS诱导的分子和细胞变化需要MEK/ERK活性。还有很多要学到的关注零星BAVM的病因以及我们的细胞培养，小鼠和斑马鱼模型将使我们能够定义与主动性和维护有关的分子，细胞和形态变化 Bavms。我们将在BAVM，成像，细胞生物学，信号和单细胞的动物模型中利用我们的专业知识 RNA测序，以获得对BAVM疾病过程的前所未有的见解。这些信息将是利用了制药干预措施的设计，以改善患者的预后。我们的建议将：1）定义可以重塑血管的KRAS突变体内皮细胞的阈值，2）识别血管床容易受到主动KRAS表达的影响，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和4）确定我们在我们的BAVM维护中对KRAS和MEK激活的要求临床前模型。这些研究将共同扩展我们对BAVM发病机理的理解，并将评估抑制KRAS/MEK途径是否可能是人类追求的可行治疗靶标 BAVM患者。