Regulation of Cellular Phenotype Change in Thoracic Aortic Aneurysms

胸主动脉瘤细胞表型变化的调节

• 批准号: 10265360
• 负责人: Jeffrey A. Jones
• 金额: --
• 依托单位: RALPH H JOHNSON VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10265360
• 关键词: ACVRL1 gene; Abdominal Aortic Aneurysm; Address; Antibodies; Antibody Therapy; Aortic Rupture; Arteries; Attenuated; Blood; Blood Pressure; C-terminal; CXCL11 gene; Cells; Chest; Complex; DDR2 gene; Data; Deposition; Development; Diabetes Mellitus; Diagnosis; Dilatation - action; Disease; Drug Controls; Endocytosis; Endosomes; Extracellular Matrix; Extracellular Matrix Proteins; Fibroblasts; Foundations; Gelatinase A; Geometry; Growth Factor; Homeostasis; Hypertension; In Vitro; Intervention; Knock-out; Laboratories; Ligands; Link; LoxP-flanked allele; MME gene; Maintenance; Matrix Metalloproteinases; Mediating; Mediator of activation protein; Membrane; Mouse Strains; Mus; Operative Surgical Procedures; Pathway interactions; Patients; Peptides; Performance; Phenotype; Phosphorylation; Play; Process; Production; Recycling; Rest; Risk; Role; Rupture; Series; Signal Transduction; Smoker; Structure; Surface; Symptoms; Tamoxifen; Testing; Therapeutic; Thoracic Aortic Aneurysm; Time; Transforming Growth Factor alpha; Transforming Growth Factor beta; Transforming Growth Factor beta Receptors; Transgenic Mice; Vascular Diseases; Veterans; Work; blood pressure regulation; cell growth regulation; cell type; design; high risk; latent TGF-beta binding protein; macrophage; military veteran; monocyte; mouse model; neutralizing antibody; prevent; programs; repaired; response; surgical risk; transdifferentiation

Thoracic aortic aneurysms (TAAs) develop as a consequence to abnormal remodeling of the aortic extracellular matrix (ECM).10 This usually asymptomatic process results in a weakened aortic wall manifested as gross dilatation that progresses to rupture. Current treatment includes blood pressure management until the risk of rupture outweighs the risk of surgical or endovascular intervention; neither of which address the underlying pathways which drive this devastating disease.11 TAA development is influenced by a series of interrelated mechanisms such as the matrix metalloproteinases (MMPs) 12-15, and dysregulation of the production and deposition of ECM proteins.16 Importantly, these mechanisms are mediated in part through changes in the resident cellular constituents within the aortic wall.17, 18 Transforming growth factor-beta (TGF-β), a soluble peptide growth factor capable of regulating the structure and composition of the aortic ECM, is a well described mediator of fibroblast phenotype.19 Current data shows that the alterations in TGF-β signaling result in a type-I TGF-β receptor switch, from a TGF-β-R1 dominant signal, to an ALK-1 dominant signal. TGF-β is sequestered within the extracellular matrix, bound by latent TGF-β binding proteins (LTBPs).21, 22 These latent complexes are proteolytic targets for key MMPs, such as membrane type-I MMP (MT1-MMP), which is induced during TAA development.8, 23 Results demonstrated that TAA development was attenuated in MT1-MMP heterozygous deficient mice, and neutralizing antibody treatment targeting either TGF-β ligands (TGF-β-NAb) or MT1-MMP activity (MT1-MMP-InhAb) was sufficient to attenuate aortic dilatation; suggesting MT1-MMP as an important mediator of TAA formation and progression. New data demonstrate an increase in the number of mature macrophages (F4/80+) at 8- and 16- weeks post-TAA induction; suggesting that macrophage-derived MT1-MMP may also contribute to TAA development. The present proposal will explore the time-dependent and cell-type specific expression of MT1-MMP using an established and well-characterized mouse model of TAA induction, and several unique transgenic mouse strains. The central hypothesis of this study is that MT1-MMP-dependent activation of TGF-β signaling is both time-dependent and cell-specific, and it will be tested through three specific aims: (1) Demonstrate that fibroblast-derived MT1-MMP is required for TGF-β release and fibroblast transdifferentiation, early in TAA development. Using a validated Tamoxifen-inducible, fibroblast-specific Cre- dependent (Col1A2-Cre-ERT2) knockout of floxed-MT1-MMP, MT1-MMP will be deleted in fibroblasts prior to TAA induction (Early), or after 4-weeks of TAA development (Late); (2) Demonstrate that macrophage-derived MT1-MMP is required for TGF-β release and the maintenance of fibroblast phenotype, late in TAA development. Using a Tamoxifen-inducible, monocyte/macrophage-specific Cre-dependent (LysM-Cre-ERT2) knockout of floxed-MT1-MMP, macrophage-derived MT1-MMP will be knockout. A) prior to TAA induction (Early), or B) after 4-weeks of TAA development (Late); and (3) Demonstrate the efficacy of the MT1-MMP activity-neutralizing antibody as a potential therapeutic for the treatment of TAA disease. Mice will be treated with the antibody prior to TAA induction (Early), or after 4-weeks of TAA development (Late). In each aim, the effects on aortic geometry and structure, the activation of TGF-β signaling (pSmad-1/5/8), fibroblast phenotype/function, and the localization of cell-type specific markers, and MT1-MMP, in the aortic wall will be recorded. Together this set of studies will establish the time-dependent and cell-type-specific expression of MT1-MMP during TAA formation and progression and define its mechanistic role in TAA development.

胸腔主动脉瘤（TAAS）是由于主动脉外的异常重塑而出现的 矩阵（ECM）.10这个通常无症状的过程导致弱的主动脉壁表现为总体 扩张发展为破裂。当前治疗包括血压管理，直到有风险 破裂大于手术或血管内干预的风险；哪一个都没有解决基础 驱动这种毁灭性疾病的途径。11TAA的发展受一系列相互关联的影响 诸如基质金属蛋白酶（MMP）12-15的机制，生产和生产失调 ECM蛋白的沉积。16重要的是，这些机制是通过变化的部分介导的 居民细胞构成主动脉壁内。17，18转化生长因子-beta（TGF-β），一种可溶性 能够调节主动脉ECM结构和组成的肽生长因子是一个很好的描述 成纤维细胞表型的介质。19当前数据表明，TGF-β信号的变化导致I型I 从TGF-β-R1显性信号到ALK-1显性信号的TGF-β受体转换。 TGF-β被隔离 在细胞外基质中，由潜在的TGF-β结合蛋白（LTBPS）结合。21，22这些潜在的复合物是 关键MMP的蛋白水解靶标，例如膜I型MMP（MT1-MMP），在TAA期间诱导 开发8，23结果表明，在MT1-MMP杂合中，TAA发育已减弱 缺乏小鼠和靶向TGF-β配体（TGF-β-NAB）或MT1-MMP的中和抗体处理 活性（MT1-MMP胞）足以减弱主动脉膨胀；建议MT1-MMP作为重要 TAA形成和进展的介体。新数据表明成熟的数量有所增加 TAA诱导后8-和16周巨噬细胞（F4/80+）；提示巨噬细胞衍生的MT1-MMP 也可能有助于TAA的发展。本提案将探讨时间依赖性和细胞类型 使用已建立且特征良好的TAA诱导小鼠模型的MT1-MMP的特定表达， 以及几种独特的转基因小鼠菌株。这项研究的中心假设是MT1-MMP依赖性 TGF-β信号的激活既有时间依赖性和细胞特异性，并且将通过三个特定 目的：（1）证明TGF-β释放和成纤维细胞需要成纤维细胞衍生的MT1-MMP 转变，在TAA发展的早期。使用经过验证的他莫昔芬可诱导的成纤维细胞特异性CRE- Floxed-MT1-MMP的依赖（COL1A2-CRE-ERT2）敲除MT1-MMP将在成纤维细胞中删除 TAA诱导（早期），或在TAA开发的4周之后（晚期）； （2）证明了巨噬细胞的衍生 MT1-MMP是TGF-β释放和成纤维细胞表型的维持所必需的，这是TAA发育后期。 使用他莫昔芬诱导，单核细胞/巨噬细胞特异性CRE依赖性（Lysm-Cre-ert2）敲除 Floxed-MT1-MMP，巨噬细胞衍生的MT1-MMP将被淘汰。 a）在TAA诱导之前（早期），或b） TAA开发的4周（晚期）； （3）证明了MT1-MMP活动中和化的效率 抗体是治疗TAA疾病的潜在理论。小鼠将用抗体进行治疗 进行TAA诱导（早期），或在TAA开发的4周之后（晚期）。在每个目标中，对主动脉几何形状的影响 和结构，TGF-β信号（PSMAD-1/5/8）的激活，成纤维细胞表型/功能以及定位 将记录主动脉壁中的细胞类型特异性标记和MT1-MMP。这组研究将在一起 在TAA形成期间建立MT1-MMP的时间依赖性和细胞类型的表达 进展并定义其在TAA发育中的机械作用。