The role of Collagen COL22A1 in intracranial aneurysms and vascular stability

胶原蛋白 COL22A1 在颅内动脉瘤和血管稳定性中的作用

• 批准号: 9926909
• 负责人: Saulius Sumanas
• 金额: $ 15.71万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-15 至 2020-08-07
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9926909
• 关键词: Adult; Affect; Alleles; Amino Acid Sequence; Aneurysm; Basement membrane; Berry; Berry Aneurysm; Biological; Biological Assay; Biological Models; Biological Process; Blood Vessels; Brain hemorrhage; CRISPR/Cas technology; Cessation of life; Chemicals; Clinical; Collagen; Data; Death Rate; Defect; Development; Disease; Embryo; Endothelin-2; Extravasation; Family member; Fibril-Associated Collagens; Frequencies; General Population; Genes; Genetic; Hemorrhage; Homologous Gene; Human; Individual; Integrins; Interruption; Intracranial Aneurysm; Intracranial Hemorrhages; Knock-in; Knowledge; Lead; Maintenance; Mediating; Modeling; Morphology; Mutation; Pathway interactions; Patients; Pericytes; Permeability; Phenotype; Population; Predisposition; Prevention; Proteins; Risk; Role; Rupture; Ruptured Aneurysm; Signal Pathway; Single Nucleotide Polymorphism; Smooth Muscle Myocytes; Structure; Subarachnoid Hemorrhage; Survivors; Testing; Therapeutic; Tight Junctions; Transmission Electron Microscopy; Variant; Vascular Permeabilities; Zebrafish; disability; drug candidate; effective therapy; exome sequencing; experimental study; fibrillin; in vivo; inducible gene expression; intracranial artery; loss of function; mutant; novel; novel therapeutics; overexpression; prevent; protein folding; repaired; screening; small molecule libraries; targeted sequencing; transcription activator-like effector nucleases; triple helix; vascular abnormality

Project Summary Intracranial aneurysms (IA) are berry- or balloon-like defects in the wall of a major intracranial artery and are present in 1-2% of the population. They commonly result in subarachnoid hemorrhage, which leads to death in 30-40% of the patients. There is currently no effective therapy to treat SAH and only limited treatment options to prevent IA rupture. Both environmental and genetic factors have been attributed to the aneurysm formation; however, the genetic factors and their underlying mechanisms are still largely unknown. We have identified mutations in collagen COL22A1 as potential contributors to the development of IAs in human patients. In the Familial Intracranial Aneurysm study, led by our collaborators, whole exome sequencing resulted in identification of a single nucleotide polymorphism (SNP) in a highly conserved region of COL22A1 present in only affected family members. However, biological function of COL22A1 is currently not known, and it is not clear if the identified mutation is causative of aneurysms in humans. We propose to use a zebrafish model to determine the function of COL22A1 in maintaining vascular integrity and to identify potential therapeutic strategies that would lead to the prevention of aneurysm formation and rupture. The protein sequence of COL22A1 is highly conserved between humans and zebrafish, and the zebrafish have emerged as a highly advantageous model system for in vivo analysis of vascular function and disease mechanisms. Our preliminary data indicate that COL22A1 zebrafish mutants display increased susceptibility to hemorrhages and show abnormal vascular dilations comparable to aneurysms in human patients, while inducible expression of the human mutant SNP results in increased frequency of hemorrhages in zebrafish embryos. We hypothesize that COL22A1 is involved in regulating vascular integrity and permeability and that mutations in COL22A1 cause intracranial aneurysms. The following specific aims are proposed: 1) Determine the functional role of COL22A1 in the maintenance of vascular stability; 2) Determine if mutations in COL22A1 cause intracranial aneurysms; 3) Perform a chemical screen to discover drug candidates that suppress hemorrhages in COL22A1 mutant embryos. Zebrafish COL22A1 mutant embryos and adults will be analyzed for morphological and functional defects. The human mutation will be modeled in zebrafish by creating a knock-in allele using a CRISPR / Cas9 mediated homology-directed repair and analyzing it for IA related phenotypes. A chemical library screen will be performed using zebrafish COL22A1 mutants to identify candidate drugs that may compensate for the deficiency in COL22A1 function. The proposed project will identify the biological function of COL22A1 homolog in vivo. It will further determine if mutations in COL22A1 cause IAs, and identify drug candidates that can be used for IA treatments. Understanding genetic causes of aneurysms will enable screening to identify patients at risk and will promote development of new treatments that can prevent devastating consequences of intracranial hemorrhages.

项目摘要 颅内动脉瘤(IA)是指位于主要颅内动脉壁上的浆果状或气球状的缺陷。 并且存在于1%-2%的人口中。它们通常会导致蛛网膜下腔出血，从而导致 30%-40%的患者死亡。目前还没有有效的治疗SAH的方法，只有有限的治疗方法 防止内膜破裂的选项。环境因素和遗传因素都被归因于动脉瘤。 然而，遗传因素及其潜在机制在很大程度上仍不清楚。 我们已经确定胶原COL22A1突变是IAS发生的潜在因素 在人类病人身上。在由我们的合作者领导的家族性颅内动脉瘤研究中， 测序结果表明，在一个高度保守的区域发现了单核苷酸多态。 COL22A1只存在于受影响的家庭成员中。然而，COL22A1的生物学功能目前还不是 目前尚不清楚这种已确认的突变是否是导致人类动脉瘤的原因。 我们建议使用斑马鱼模型来确定COL22A1在维持血管中的功能 并确定有助于预防动脉瘤形成的潜在治疗策略 和破裂。COL22A1的蛋白质序列在人类和斑马鱼之间高度保守，并且 斑马鱼已经成为一种非常有利的模型系统，用于体内分析血管功能和 疾病机制。我们的初步数据表明，COL22A1斑马鱼突变体的数量增加了 人类对出血的易感性和表现出类似于动脉瘤的异常血管扩张 患者，虽然人类突变SNP的可诱导表达会导致出血频率增加 在斑马鱼胚胎中。我们假设COL22A1参与调节血管完整性和 通透性和COL22A1基因突变会导致颅内动脉瘤。以下是具体目标 建议：1)确定COL22A1在维持血管稳定性中的功能作用；2)确定是否 COL22A1基因突变导致颅内动脉瘤；3)进行化学筛查以发现药物 抑制COL22A1突变胚胎出血的候选基因。斑马鱼COL22A1突变胚胎 成人将接受形态和功能缺陷的分析。人类的突变将被模拟为 斑马鱼通过使用CRISPR/Cas9介导的同源定向修复和 对其进行IA相关表型分析。将使用斑马鱼COL22A1进行化学库筛选 突变体以确定可能弥补COL22A1功能缺陷的候选药物。 拟议的项目将确定COL22A1同源物在体内的生物学功能。它将进一步 确定COL22A1突变是否导致IAS，并确定可用于IA治疗的候选药物。 了解动脉瘤的遗传原因将使筛查能够识别有风险的患者，并将促进 开发新的治疗方法，以防止颅内出血的破坏性后果。