CCN1-induced Senescence in the Cerebral Vasculature

CCN1 诱导的脑血管衰老

• 批准号: 10370877
• 负责人: Jose Felix Moruno Manchon
• 金额: $ 23.4万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10370877
• 关键词: Aging; Bilateral; Binding; Binding Proteins; Blood - brain barrier anatomy; Blood Vessels; Brain; Carotid Stenosis; Cell Aging; Cell Cycle; Cell Cycle Progression; Cell Proliferation; Cell physiology; Cells; Cerebrovascular Circulation; Cerebrovascular system; Cerebrum; Chronic; Cognitive; Cognitive deficits; Coupled; Cysteine; DNA; DNA Damage; Data; Dementia; Disease; Down-Regulation; Endothelial Cells; Endothelium; Extracellular Matrix Proteins; FMR1; Fibroblasts; Functional disorder; G-Quartets; GTP-Binding Protein alpha Subunits, Gs; Gait; Genes; Guanine; Heterochromatin; Impaired cognition; Impairment; Integrin alpha6beta1; Integrins; Ligands; Link; Malignant Neoplasms; Measures; Mediating; Messenger RNA; Microscopy; Modeling; Molecular; Motor; Mus; Operative Surgical Procedures; Pathologic; Patients; Permeability; Phenotype; Play; Protein Deficiency; Proteins; RNA; RNA-Binding Proteins; Ribosomes; Role; Scheme; Secondary to; Signal Pathway; Structure; System; Techniques; Testing; Tissues; Translations; Tumor Suppressor Proteins; Up-Regulation; Viral Vector; adhesion receptor; aged; aging brain; blood-brain barrier disruption; brain endothelial cell; cell injury; cerebral hypoperfusion; cerebrovascular pathology; cognitive function; conditioned fear; cysteine rich protein; dementia risk; design; motor deficit; mouse model; mutant; negative affect; novel; object recognition; overexpression; prevent; senescence; vascular cognitive impairment and dementia; vector; white matter

Project Summary Vascular contributions to cognitive impairment and dementia (VCID) includes a number of different disorders identified by cognitive deficits secondary to cerebrovascular pathology. Senescence in the cerebral endothelium has been proposed as a mechanism that can drive blood brain barrier disruption (BBB), which precedes VCID. However, the mechanisms that drive endothelial cells to senescence are not fully understood. Guanine-quadruplex (G4) is a non-canonical secondary structure formed in G-rich sequences in DNA and RNA. Importantly, G4 stabilization promotes cellular senescence. Particularly, stabilization of G4s in mRNA (rG4s) stalls ribosomes in the elongation stage and blocks translation. This mechanism is promoted by rG4- binding proteins. Fragile X mental retardation protein (FMRP) binds to the rG4 of tumor suppressors and components of signaling pathways involved in senescence. FMRP deficiency has been associated with senescence in different tissues. We found that overexpressing FMRP in cultured cerebral endothelial cells (CEC) mitigated DNA damage, an important cause of cell senescence. We found that G4 stabilization promoted endothelial senescence and enhanced the levels of Cysteine-rich angiogenic inducer 61 (Cyr61/CCN1), a matricellular protein secreted by endothelial cells in the brain. CCN1 is considered a component of the senescence-associated secretory phenotype (SASP). In fibroblasts, CCN1 induces senescence by binding to integrin α6β1. In our study, we will use bilateral carotid artery stenosis (BCAS) that induces chronic cerebral hypoperfusion and models VCID in mice. We found that BCAS mice showed enhanced levels of G4s, CCN1 and senescence markers. We hypothesize that the endothelial senescence associated with G4 stabilization could be mitigated in mice and hence prevent BBB disruption and cognitive deficits. To test our hypothesis, we propose two aims: In Aim 1, we will selectively target the brain endothelium of young mice with a vector encoding a mutant form of CCN1 that cannot bind to α6β1. We will measure motor and cognitive function, and BBB permeability, and senescence in the brain. In Aim 2, we will determine if upregulating FMRP mitigates motor and cognitive deficits, BBB impairment, and senescence in the cerebral vasculature of aged BCAS mice. Overall, this study proposes two independent strategies to mitigate VCID-associated phenotypes induced by senescence in the cerebrovasculature: impeding the CCN1-α6β1binding in the cerebral endothelium; and upregulating FMPR specifically in the brain vasculature of mice.

项目概要 血管对认知障碍和痴呆 (VCID) 的影响包括许多不同的疾病 通过继发于脑血管病理学的认知缺陷来识别。脑内皮细胞的衰老 已被提议作为一种可以驱动血脑屏障破坏 (BBB) 的机制，该机制先于 VCID。 然而，驱动内皮细胞衰老的机制尚不完全清楚。 鸟嘌呤四联体 (G4) 是 DNA 中富含 G 的序列中形成的非规范二级结构， 核糖核酸。重要的是，G4 稳定会促进细胞衰老。特别是 mRNA 中 G4 的稳定性 (rG4s) 在延伸阶段使核糖体停滞并阻止翻译。该机制由 rG4- 促进 结合蛋白。脆性 X 智力迟钝蛋白 (FMRP) 与肿瘤抑制因子的 rG4 结合， 参与衰老的信号通路的组成部分。 FMRP 缺陷与 不同组织的衰老。我们发现在培养的脑内皮细胞（CEC）中过度表达 FMRP 减轻DNA损伤，这是细胞衰老的一个重要原因。 我们发现 G4 稳定促进内皮衰老并提高富含半胱氨酸的水平 血管生成诱导物 61 (Cyr61/CCN1)，一种由大脑内皮细胞分泌的基质细胞蛋白。 CCN1 是 被认为是衰老相关分泌表型（SASP）的一个组成部分。在成纤维细胞中，CCN1 通过与整合素 α6β1 结合诱导衰老。 在我们的研究中，我们将使用双侧颈动脉狭窄（BCAS）来诱导慢性脑灌注不足和 在小鼠中建立 VCID 模型。我们发现 BCAS 小鼠表现出 G4s、CCN1 和衰老水平增强 标记。 我们假设小鼠中与 G4 稳定相关的内皮衰老可以减轻 因此可以防止血脑屏障破坏和认知缺陷。为了检验我们的假设，我们提出两个目标： 在目标 1 中，我们将用编码突变形式的载体选择性地靶向幼鼠的脑内皮 CCN1 不能与 α6β1 结合。我们将测量运动和认知功能以及血脑屏障渗透性，以及 大脑衰老。 在目标 2 中，我们将确定上调 FMRP 是否可以减轻运动和认知缺陷、BBB 损伤和 老年 BCAS 小鼠脑血管系统的衰老。 总体而言，本研究提出了两种独立的策略来减轻 VCID 相关的表型 脑血管系统衰老：阻碍脑内皮细胞中的 CCN1-α6β1 结合；和 特别是在小鼠的脑血管系统中上调 FMPR。