Coordinated resident macrophage-tenocyte signaling in tendon formation

肌腱形成过程中协调的常驻巨噬细胞-肌腱细胞信号传导

• 批准号: 10742461
• 负责人: Nathaniel A. Dyment
• 金额: $ 18.7万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10742461
• 关键词: Ablation; Address; Adult; Affect; Age; Biology; CSF1 gene; Cell Differentiation process; Cell Lineage; Cells; Cellular biology; Clinical; Coculture Techniques; Collagen; Communication; Data; Development; Embryo; Endothelial Cells; Extracellular Matrix; Fascicle; Fibroblasts; Flow Cytometry; Future; Growth; Growth Factor; Growth and Development function; Homeostasis; Impairment; In Situ; Knowledge; Label; Ligands; Macrophage; Macrophage Colony-Stimulating Factor; Macrophage Colony-Stimulating Factor Receptor; Maintenance; Mechanics; Messenger RNA; Mus; Neurons; Osteoblasts; Outcome; PTPNS1 gene; Pattern; Phenotype; Play; Population; Positioning Attribute; Proliferating; Qualifying; Receptor Signaling; Reporting; Role; Signal Transduction; Source; Spatial Distribution; Stains; Structure; Tendon structure; Testing; Time; Tissues; Yolk Sac; cell type; improved; insight; novel; postnatal; regenerative approach; repaired; single-cell RNA sequencing; spatiotemporal; tendon development

Summary Despite the vast knowledge of the structure and mechanical function of mature tendons, the understanding of tenogenic cell differentiation during development and how cell types from non-tenogenic origins, such as macrophages, influence tenogenesis is limited. Tissue resident macrophages play key roles in the development of several tissues and colony stimulating factor 1 receptor (CSF1R) signaling is essential for their differentiation and survival. The source of ligands that act on CSF1R (CSF1 being the most common) often originate from adjacent resident cells. In addition to CSF1R signaling acting on the macrophages, macrophages often produce trophic factors that act on the adjacent resident cells to regulate aspects of tissue development. In exciting new data, we demonstrate that CSF1R-expressing resident macrophages are situated adjacent to CSF1-expressing tenocytes within linear arrays in the tendon fascicle from initial formation (E15.5) into adulthood, these resident macrophages rapidly accumulate to nearly 10% of the total cell population within tendons during early postnatal growth, and CSF1 produced by tenogenic cells is required for their survival. Additionally, these macrophages internalize collagen in situ, which may indicate a potential role in matrix remodeling during growth and development. Despite their relative abundance and presumed communication with adjacent tenocytes, our limited understanding of the role of resident macrophages in tendon growth and development and potential trophic signaling to tenocytes are significant gaps in knowledge. As macrophages are critical to the development and repair of numerous tissues, defining their role in tendon development will provide insight into signaling mechanisms that could be leveraged in future therapies to improve repair outcomes, which is an unmet clinical need. To address these gaps in knowledge, this proposal will define the ontogeny, distribution, and phenotypic profile of resident macrophages and establish their cross-talk with tenocytes to regulate tendon formation during growth and development. Our central hypothesis is that stable macrophage-tenocyte cross-talk exists and this communication is necessary for tendon formation. Aim 1 will define the ontogeny, abundance, and distribution of resident macrophages with respect to Csf1-expressing tenocytes and the phenotypic profile of these cells at multiple stages of growth and development. Aim 2 will then establish the cross-talk between macrophages and adjacent tenocytes and its role in tendon formation and growth. In this proposal, we will elucidate the importance of stable macrophage-tenocyte cross-talk in promoting cell differentiation and tendon formation in growth and development, thus providing new and critical insight to tendon cell biology that will inform future regenerative strategies.

概括 尽管人们对成熟肌腱的结构和机械功能有大量的了解，但对 发育过程中的肌腱细胞分化以及非肌腱起源的细胞类型如何，例如 巨噬细胞对肌腱形成的影响有限。组织驻留巨噬细胞在发育中发挥关键作用 多种组织的分化，集落刺激因子 1 受体 (CSF1R) 信号传导对于它们的分化至关重要 和生存。作用于 CSF1R（CSF1 最常见）的配体来源通常来自 相邻的常驻牢房。除了作用于巨噬细胞的 CSF1R 信号传导外，巨噬细胞还经常产生 作用于邻近常驻细胞以调节组织发育的营养因子。在令人兴奋的新 数据，我们证明表达 CSF1R 的驻留巨噬细胞位于表达 CSF1 的附近 从最初形成（E15.5）到成年期，肌腱束中线性阵列内的肌腱细胞，这些常驻 出生后早期，巨噬细胞迅速积累到肌腱内细胞总数的近 10% 生长，肌腱细胞产生的 CSF1 是其生存所必需的。此外，这些巨噬细胞 原位内化胶原蛋白，这可能表明在生长和生长过程中基质重塑中的潜在作用 发展。尽管它们相对丰富并且推测与邻近的肌腱细胞有交流，但我们的 对常驻巨噬细胞在肌腱生长、发育和潜力中的作用的了解有限 肌腱细胞的营养信号传导是知识上的重大空白。由于巨噬细胞对于发育至关重要 和修复许多组织，定义它们在肌腱发育中的作用将提供对信号传导的深入了解 可以在未来的治疗中利用机制来改善修复结果，这是一个未满足的临床问题 需要。为了解决这些知识差距，该提案将定义个体发育、分布和表型 驻留巨噬细胞的概况并建立其与肌腱细胞的串扰以调节肌腱形成 成长和发展。我们的中心假设是存在稳定的巨噬细胞-肌腱细胞串扰，并且这 沟通对于肌腱的形成是必要的。目标 1 将定义个体发育、丰度和分布 常驻巨噬细胞与表达 Csf1 的肌腱细胞的关系以及这些细胞的表型特征 成长和发展的多个阶段。目标 2 将建立巨噬细胞和 相邻的肌腱细胞及其在肌腱形成和生长中的作用。在本提案中，我们将阐明重要性 稳定的巨噬细胞-肌腱细胞串扰在促进细胞分化和生长和肌腱形成中的作用 的发展，从而为肌腱细胞生物学提供新的、重要的见解，为未来的再生提供信息 策略。