Elucidating mechanisms of hereditary hemorrhagic telangiectasia 2 gene-mediated arteriovenous malformation development via eNOS signaling using in vivo two-photon imaging in a preclinical mouse model

在临床前小鼠模型中使用体内双光子成像通过 eNOS 信号传导阐明遗传性​​出血性毛细血管扩张症 2 基因介导的动静脉畸形发育的机制

• 批准号: 10588596
• 负责人: Kayla Branyan-Schroer
• 金额: $ 1.44万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-19 至 2022-04-18
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10588596
• 关键词: ACVRL1 gene; Affect; Animal Behavior; Animal Model; Animals; Area; Arteries; Arteriovenous malformation; Blood Vessels; Blood capillaries; Blood flow; Brain; Caliber; Cell Count; Cell Proliferation; Characteristics; Clinical; Data; Development; Dimensions; Disease; Disease Progression; Ear; Endothelial Cells; Endothelium; Epilepsy; Epistaxis; Etiology; Evaluation; Exhibits; Family; Floods; Gastrointestinal Hemorrhage; Gene Mutation; Generations; Genes; Genetic Diseases; Genetic Recombination; Goals; Headache; Health behavior; Hemorrhage; Hereditary hemorrhagic telangiectasia; Histopathology; Human; Image; Immunofluorescence Immunologic; Impairment; In Vitro; Incidence; Injections; Investigation; Knowledge; Lead; Lectin; Lesion; Liver; LoxP-flanked allele; Lung; Measures; Mediating; Microscopic; Modeling; Mus; Mutant Strains Mice; NOS3 gene; Neurologic; Neurologic Deficit; Nose; Organ; Oxidative Stress; PECAM1 gene; Pathology; Patients; Penetration; Persons; Pharmaceutical Preparations; Phenotype; Prevention; Prevention strategy; Preventive therapy; Process; Production; Reporting; Research; Retina; Risk; Shapes; Signal Transduction; Skin; Stains; Stroke; Structure; Superoxide Dismutase; Superoxides; Surface; Symptoms; Tamoxifen; Techniques; Telangiectasis; Testing; Transforming Growth Factor beta; Type I Activin Receptors; Vascular System; Vascular remodeling; Veins; Work; activin A; alternative treatment; base; blood vessel development; cadherin 5; clinically relevant; curative treatments; in vivo; in vivo two-photon imaging; innovation; insight; malformation; mimetics; mortality; mouse model; notch protein; novel; novel therapeutics; postnatal; pre-clinical; prevent; promoter; rare genetic disorder; receptor; sepiapterin; tetrahydrobiopterin; therapy development; tool; treatment strategy; two-photon; vascular abnormality

Project Summary The long-term goal of this project is to identify an appropriate preclinical mouse model to characterize the etiology of Hereditary hemorrhagic telangiectasia (HHT) and to develop novel treatment options for the disease. HHT is a genetic disorder with arteriovenous malformations (AVMs) as a core pathology throughout the body. AVMs are abnormal direct connections from arteries to veins without intervening capillaries. Symptoms of HHT include telangiectasias, epistaxis, severe headache, epilepsy, stroke, gastrointestinal bleeding, and AVMs in brain, lung, and liver. The worldwide estimated incidence of HHT is 1:50002, but 90% of people with HHT are undiagnosed. Currently, there is no prevention or cure for the major clinical manifestations of HHT, calling for the development of better treatment strategies. The TGFβ type I receptor activin A receptor-like type 1 (ACVRL1 or Alk1) gene has been implicated in the etiology of HHT type 2 (HHT2), and mutation of this gene is estimated to underlie 25- 57% of all HHT cases3–7. Alk1 is primarily expressed in endothelial cells and is essential for vascular development8–10. Previous mouse models of HHT2, based on deletion of Alk1, exhibited certain disease aspects11–14. However, the existing animal models are not ideal animal models for HHT, as animals either die early by postnatal day 5 (homozygous deletion) or develop vascular lesions with long latency and incomplete penetration (heterozygous deletion) lacking key HHT symptoms, e. g. nosebleed15. Therefore, there is a critical need to develop a better preclinical animal model that better reflects the vascular lesions presented in HHT2 patients, aiding the efforts to uncover the mechanisms of the disease progression and develop potential preventative and treatment strategies for HHT therapy. To resolve these gaps in knowledge, our lab has created a novel mouse model in which Alk1 is deleted postnatally in arterial endothelial cells. Preliminary data suggest that these mice survived beyond postnatal day 27 with HHT-like vascular lesions in multiple organs, offering a valuable animal model of HHT2 to study the disease processes and underlying mechanisms. I will characterize the HHT-like lesions present in these mice by examining the gross pathology, histopathology, animal health, and behavior of the animals. Further, I will examine the vascular structure and function through microscopic imagining, including two-photon in vivo live imaging. Finally, I will characterize the oxidative stress profile of the mice by measuring superoxide and NO levels, while also treating the mice with a superoxide dismutase mimetic, TEMPOL and a synthetic BH4 compound, sepiapterin to determine the effects of oxidative stress in the formation and prevention of AVMs in this model. The successful completion of this project will provide a novel tool for the investigation of mechanism underlying Alk1-mediated HHT formation and for the development of novel preventative and curative therapies for patients with HHT2.

项目摘要 这个项目的长期目标是找出一个合适的临床前小鼠模型来表征病因学。 目的是治疗遗传性出血性毛细血管扩张症(HHT)，并为该疾病开发新的治疗方案。HHT是 动静脉畸形是一种遗传性疾病，以全身动静脉畸形为核心病理改变。Avm是 从动脉到静脉的异常直接连接，没有中间的毛细血管。HHT的症状包括 毛细血管扩张，鼻出血，严重头痛，癫痫，中风，胃肠道出血，脑，肺， 还有肝脏。据估计，世界范围内高血压的发病率为1：50002，但90%的高血压患者没有得到诊断。 目前，HHT的主要临床表现尚无防治措施，亟待发展。 更好的治疗策略。转化生长因子βI型受体激活素A受体样1型基因 与HHT2型(HHT2)的病因学有关，该基因的突变被估计为25- 57%的HHT病例3-7。Alk1主要在血管内皮细胞表达，是血管必需的 发展8-10.以前的HHT2小鼠模型，基于Alk1的缺失，表现出某些疾病 然而，现有的动物模型并不是HHT的理想动物模型，因为动物要么死亡 出生后第5天早期(纯合子缺失)或出现潜伏期长且不完全的血管病变 穿透(杂合缺失)缺乏关键的高血压症状，例如流鼻血15。因此，有一个关键的 需要开发更好的临床前动物模型来更好地反映HHT2中出现的血管病变 患者，帮助努力揭示疾病发展的机制和发展潜力 HHT治疗的预防和治疗策略。为了解决这些知识上的差距，我们的实验室创造了 一种新的小鼠模型，在该模型中，Alk1出生后在动脉内皮细胞中被删除。初步数据显示 这些小鼠在出生后第27天存活，多个器官出现HHT样血管病变，提供了一种 HHT2有价值的动物模型，用于研究疾病过程和潜在机制。我将描述一下 通过大体病理、组织病理学、动物健康和组织学检查，这些小鼠体内存在HHT样病变。 动物的行为。此外，我还将通过显微镜检查血管的结构和功能 想象，包括双光子活体成像。最后，我将描述氧化应激的特征 通过测量小鼠的超氧化物歧化和一氧化氮水平，同时用超氧化物歧化酶模拟物治疗小鼠， 坦普尔和合成的BH4化合物，sepiapterin，以确定氧化应激在地层中的影响 以及在该模型中动静脉动静脉畸形的预防。该项目的成功完成将为 Alk1介导HHT形成机制的研究及新型药物的开发 HHT2患者的预防和治疗。