Defining the Role of Type III Collagen in Neonatal Tendon Development and Healing

定义 III 型胶原蛋白在新生儿肌腱发育和愈合中的作用

• 批准号: 10605477
• 负责人: Margaret Kathryn Tamburro
• 金额: $ 4.77万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-07 至 2025-12-06
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10605477
• 关键词: Acceleration; Adult; Aging; Biology; Blood Vessels; Cells; Cellular Infiltration; Cellularity; Characteristics; Cicatrix; Clinical; Collagen; Collagen Fiber; Collagen Fibril; Collagen Type I; Collagen Type III; Deposition; Development; Developmental Process; Diameter; Dryness; Economic Burden; Ehlers-Danlos Syndrome; Environment; Extracellular Matrix; Fibroblasts; Foundations; Gene Expression; Glean; Growth; Immunohistochemistry; Incidence; Infiltration; Injury; Integrins; Investigation; Knock-out; Laboratory Research; Measures; Mechanics; Menopause; Minor; Modeling; Mus; Natural regeneration; Neonatal; Orthopedics; Pennsylvania; Perinatal; Phase; Play; Predisposition; Process; Property; Proteomics; Regulation; Reproducibility; Research Personnel; Resistance; Role; Scientific Inquiry; Smoking; Stress; Tendon Injuries; Tendon structure; Testing; Time; Tissue Engineering; Tissues; Training; Transmission Electron Microscopy; Universities; Weight; Work; clinically relevant; comparative; crosslink; defined contribution; density; fetal; fibrillogenesis; healing; improved; inflammatory milieu; injured; innovation; insight; joint mobilization; knock-down; mechanical properties; migration; mouse model; multidisciplinary; neonatal mice; neonate; novel; postnatal; postnatal development; prenatal; progenitor; recruit; regenerative; regenerative approach; response; response to injury; stem cells; tendon development; therapeutic target; viscoelasticity; wound healing

Project Abstract Tendons can withstand large forces due to a highly aligned, dense collagen matrix. However, their low cellularity and relative inability to recruit reparative cells post-injury, as well as susceptibility to excessive scarring, results in loss of tendon structure and mechanical function. Type I collagen (Col1) is the primary collagen of healthy tendon and type III collagen (Col3) is a minor constituent that increases in response to injury. Persistently increased Col3 contributes to persistent fibrovascular scarring and structural and functional deficits in the healing tendon. In perinatal tendons, Col3 is increased, similar to the injured state, compared to healthy mature tendons. Unlike the healing response, the process of neonatal tendon development yields a structurally and functionally superior tendon with a highly aligned Col1-dense matrix. Moreover, neonatal developing tendon demonstrates improved efficiency and quality of healing compared to healing mature tendon. Understanding the role of Col3 in the developmental and healing processes of the neonatal tendon will increase our ability to recapitulate tendon development with tissue engineering and improve tendon injury treatment. Therefore, our overall objective is to delineate the contribution of Col3 to development and healing in the neonatal tendon through modulation of matrix properties and cellular activity. Specifically, we will test the hypothesis that Col3 is crucial for early neonatal development but contributes less to regulation of development at later time points as relative Col3 in the tendon decreases. We also hypothesize that the neonatal tendon has enhanced capacity for a robust proliferative response to tendon injury which creates a Col3-dense healing matrix favorable for tendon progenitor migration and differentiation to ultimately deposit aligned, Col1 fibrils which restore tendon structure and function. To test these hypotheses, we generated a novel, inducible Col3 deficient mouse (i.e. Col3a1F/F) to temporally control Col3 reduction. The study aims are: Aim 1: Define the temporal dynamics of the regulatory function(s) of Col3 during phases of neonatal tendon development and Aim 2: Define the regulatory function(s) of Col3 during phases of neonatal healing. Viscoelastic mechanical testing, transmission electron microscopy, immunohistochemistry, gene expression, proteomics, and 11 integrin analyses will be used to assess the structural, mechanical, and compositional properties of tendons in both aims. Insights gleaned from this work will be relevant to a variety of conditions that reduce Col3 expression including vascular Ehlers Danlos syndrome, aging, smoking and menopause and will highlight therapeutic targets for enhancing tendon injury treatment. The proposed work will be carried out in a world- class training environment at the University of Pennsylvania’s McKay Orthopaedic Research Laboratory. This environment combined with an expert sponsorship team, including experts in studies of tendon structure and function as well as matrix biology, will fully support completion of this proposal and facilitate development into a competent independent investigator capable of producing rigorous and reproducible clinically relevant work.

项目摘要 由于高度排列、致密的胶原蛋白基质，肌腱可以承受很大的力。然而，他们的低 细胞结构和损伤后相对无法募集修复细胞，以及对过度损伤的敏感性 疤痕，导致肌腱结构和机械功能丧失。 I 型胶原蛋白 (Col1) 是主要的 健康肌腱的胶原蛋白和 III 型胶原蛋白 (Col3) 是一种次要成分，会随着 受伤。持续增加的 Col3 会导致持续的纤维血管疤痕以及结构和功能 愈合肌腱的缺陷。在围产期肌腱中，与受伤状态相比，Col3 增加 健康成熟的肌腱。与愈合反应不同，新生儿肌腱发育过程会产生 结构和功能优越的肌腱，具有高度对齐的 Col1 密集矩阵。此外，新生儿 与成熟的肌腱相比，发育中的肌腱显示出更高的愈合效率和质量 肌腱。了解 Col3 在新生儿肌腱发育和愈合过程中的作用将有助于 提高我们通过组织工程重现肌腱发育并改善肌腱损伤的能力 治疗。因此，我们的总体目标是描述 Col3 对发育和治疗的贡献 通过调节基质特性和细胞活性，在新生儿肌腱中发挥作用。具体来说，我们将测试 假设 Col3 对新生儿早期发育至关重要，但对发育调节的贡献较小 在稍后的时间点，随着肌腱中相对 Col3 的减少。我们还假设新生儿肌腱具有 增强对肌腱损伤的强烈增殖反应的能力，从而产生 Col3 密集愈合 有利于肌腱祖细胞迁移和分化的基质，最终沉积对齐的 Col1 原纤维 恢复肌腱的结构和功能。为了测试这些假设，我们生成了一种新颖的、可诱导的 Col3 缺陷小鼠（即 Col3a1F/F）暂时控制 Col3 减少。研究目标是： 目标 1：定义 新生儿肌腱发育阶段 Col3 调节功能的时间动态 目标 2：定义 Col3 在新生儿愈合阶段的调节功能。粘弹性力学 测试、透射电子显微镜、免疫组织化学、基因表达、蛋白质组学和 11 整合素分析将用于评估肌腱的结构、机械和成分特性 这两个目标。从这项工作中收集到的见解将与减少 Col3 的各种条件相关 表达包括血管埃勒斯丹洛斯综合征、衰老、吸烟和更年期，并将突出显示 加强肌腱损伤治疗的治疗目标。拟议的工作将在世界范围内进行 宾夕法尼亚大学麦凯骨科研究实验室的课堂培训环境。这 环境与专家赞助团队相结合，包括肌腱结构研究专家和 功能以及基质生物学，将全力支持该提案的完成，并促进发展成为一个 有能力进行严格且可重复的临床相关工作的有能力的独立研究者。