The role of dendritic cells in heart valve extracellular matrix remodeling, homeostasis, and disease

树突状细胞在心脏瓣膜细胞外基质重塑、稳态和疾病中的作用

• 批准号: 10672638
• 负责人: Brittany A. Gonzalez
• 金额: $ 1.71万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10672638
• 关键词: Ablation; Address; Adult; Affect; Antigen-Presenting Cells; Biomechanics; Cell Communication; Cell Density; Cell Proliferation; Cells; Collagen; Collagen Fiber; Data; Defect; Dendritic Cells; Dendritic cell activation; Development; Disease; Disease Progression; Elastin; Embryo; Environment; Enzymes; Extracellular Matrix; Extracellular Matrix Proteins; FBN1; Gene Mutation; Generations; Genes; Glycosaminoglycans; Heart Valves; Homeostasis; Immune; Incidence; Individual; Infiltration; Inflammatory Response; Injections; Innate Immune System; Intestines; Knock-in; Knock-in Mouse; Knockout Mice; Knowledge; Lead; Leukocytes; Lipopolysaccharides; Live Birth; Liver; Macrophage; Marfan Syndrome; Matrix Metalloproteinases; Mechanics; Mediating; Medical; Mitral Valve; Mus; Mutant Strains Mice; Myeloid Cells; Organ; PTPRC gene; Pathology; Peptide Hydrolases; Physiological; Population; Production; Property; Proteins; Proteoglycan; Reporter; Role; Spleen; Structure; Testing; Therapeutic; Time; Tissues; Wild Type Mouse; aortic valve; cytokine; dominant genetic mutation; genetic signature; heart function; immunogenic; improved; in vivo; inflammatory milieu; inflammatory modulation; insight; malformation; mechanical signal; monocyte; mouse model; postnatal; prevent; receptor; repaired; standard of care; transcriptome sequencing

Project Summary/Abstract Normal heart valve structure and composition development during valve remodeling, starting at late embryonic stages and continues to mature postnatally. Valve remodeling results in a stratified extracellular matrix (ECM), decreased cell density and reduction in cell proliferation. Congenital valve malformations include abnormalities in valve remodeling such as ECM disruption and disorganization. Congenital heart valve abnormalities due to ECM gene mutations and defects, often lead to myxomatous valve disease (MVD). Progressive MVD is characterized by collagen fiber fragmentation, replacement of mucopolysaccharides and proteoglycans, leaflet thickening, and insufficiency, but the mechanisms mediating progressive valve degeneration remain unknown and there are no therapies to prevent or reverse MVD. Recently, our group identified immune cell populations in normal aortic and mitral valves composed of predominantly dendritic cells and myeloid cells. We found that in a murine model of Marfan Syndrome, Fbn1C1039G/+, with MVD that the mitral valve undergoes abnormal postnatal maturation of the ECM accompanied by an increase in immune cells near regions of collagen breakdown and proteoglycan expansion. It was found that deficiency of infiltrating CCR2+ monocytes inhibited the progression of myxomatous generation in MFS mice, with decreased numbers of macrophages and reduced valve thickening, suggesting that immunogenic ECM components and immune cells may be key drivers of MVD progression. Based on RNA sequencing of normal murine valves at postnatal days 7 and 30, dendritic cells (DCs) are the only CCR2+ immune cell subpopulation as a gene signature of top 20 correlated genes [6], suggesting a potential role of DCs in valvular ECM remodeling. Therefore, we hypothesize that immature Xcr1 DCs mediate homeostasis during mitral valve postnatal ECM remodeling and maturation but lead to MVD progression in MFS when activated. We propose two aims to elucidate the role of DCs in ECM remodeling, maturation and disease. In Aim 1, we will determine if activated monocytes are sufficient to drive ECM remodeling, maturation and MVD progression in MFS mitral valves in a murine model injected with Lipopolysaccharide (LPS). The localization and activate of DCs will be determined by assessing DC activation, morphometric ECM changes, inflammatory response in DC knock-in mice models. In Aim 2, we will determine if Xcr1 DCs in the mitral valves are required for ECM remodeling and MVD progression in MFS by accessing DC activation, morphometric ECM changes, inflammatory response and functional and biomechanical changes in DC knock-in and DC knockout mice crossed with fibrillin 1 mutant mice. Understanding DC contributions to MVD in MFS and disease progression will advance therapeutic strategies aimed at preventing or reversing MVD.

项目摘要/摘要 阀重塑期间正常心脏瓣膜结构和组成发展，从迟到开始 胚胎阶段并在产后继续成熟。阀重塑导致分层的细胞外基质 （ECM），细胞密度降低和细胞增殖降低。先天性瓣膜畸形包括 阀重塑的异常，例如ECM破坏和混乱。先天性心脏瓣膜 ECM基因突变和缺陷引起的异常，通常导致粘液瓣疾病（MVD）。 进行性MVD的特征是胶原纤维碎片，替代粘多糖和 蛋白聚糖，传单增厚和不足，但介导进行性阀的机制 退化仍然未知，没有预防或逆转MVD的疗法。最近，我们的小组 在正常主动脉瓣和二尖瓣中鉴定出的免疫细胞群，主要由树突状细胞组成 和髓样细胞。我们发现，在Marfan综合征的鼠模型中，二尖瓣有MVD 瓣膜经历ECM的异常产后成熟，伴随着附近的免疫细胞的增加 胶原蛋白分解和蛋白聚糖扩展区域。发现浸润CCR2+的缺乏 单核细胞抑制了MFS小鼠中粘液肿的产生的进展，数量减少 巨噬细胞和瓣膜变厚，表明免疫原性ECM成分和免疫细胞 可能是MVD进展的关键驱动因素。基于产后正常鼠瓣的RNA测序 7和30，树突状细胞（DC）是唯一的CCR2+免疫细胞亚群，作为前20名的基因特征 相关基因[6]，表明DC在瓣膜ECM重塑中的潜在作用。因此，我们假设 未成熟的XCR1 DCS介导了二尖瓣后ECM重塑和 激活后成熟但导致MFS的MVD进展。我们提出了两个旨在阐明角色的目标 ECM重塑，成熟和疾病中的DC。 在AIM 1中，我们将确定活化的单核细胞是否足以驱动ECM重塑，成熟 在注射脂多糖（LPS）的鼠模型中，MFS二尖瓣中的MVD进展。这 DC的定位和激活将通过评估直流激活，形态计量计量的变化，确定 直流敲门小鼠模型中的炎症反应。在AIM 2中，我们将确定二尖瓣中的XCR1 DC是否 通过访问DC激活，形态计量学ECM需要MFS中ECM重塑和MVD进展 DC敲入和DC敲除的变化，炎症反应以及功能和生物力学变化 与纤维蛋白1突变小鼠交叉的小鼠。了解DC对MFS和疾病中MVD的贡献 进展将推进旨在防止或逆转MVD的治疗策略。