Formation of a functional tendon enthesis during development and healing

在发育和愈合过程中形成功能性肌腱附着点

• 批准号: 10587399
• 负责人: Stavros Thomopoulos
• 金额: $ 51.69万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10587399
• 关键词: Ablation; Acute; Adult; Agonist; Architecture; Automobile Driving; Biological Assay; Biomechanics; Cartilage; Cell Differentiation process; Cell Lineage; Cells; Chondrocytes; Cicatrix; Connective Tissue; Cues; Development; Differentiation Antigens; Embryo; Erinaceidae; Event; Extracellular Matrix; Failure; Fibrocartilages; Future; Genetic; Genetic Transcription; Goals; Growth; Health; Individual; Injury; Knee; Knowledge; Mechanics; Mediating; Minerals; Modeling; Molecular; Morphology; Mus; Muscle; Natural regeneration; Neonatal; Older Population; Operative Surgical Procedures; Outcome; Pain; Pathway interactions; Phenotype; Physiological; Pilot Projects; Population; Process; Quality of life; Repeat Surgery; Reporter; Research; Role; Rotator Cuff; Rupture; Shoulder; Signal Transduction; Site; Stress; Tendon Injuries; Tendon structure; Testing; Therapeutic; Tissues; Transcriptional Regulation; United States; Work; anterior cruciate ligament injury; bone; bone healing; bone repair; clinically significant; fetal; gain of function; healing; improved; loss of function; mechanical properties; mineralization; patient population; postnatal; postnatal development; prevent; progenitor; programs; regenerative; regenerative approach; repaired; response; smoothened signaling pathway; stem cell differentiation; stem cell niche; stem cell therapy; stem cells; transcription factor; transcriptome

SUMMARY/ABSTRACT Tendon injuries often occur near their bony attachments, requiring surgical repair of tendon to bone. Outcomes after repair, however, are poor and result in pain, reinjury, and repeated surgeries. Rotator cuff repair, for example, is among the most common shoulder surgeries, yet is plagued by 20-94% failure rates. At the root of these poor outcomes is a lack of regeneration of the enthesis, the specialized tissue that connects healthy tendon and bone. In contrast to the disorganized scar that forms during tendon-to-bone healing, the healthy enthesis has spatial gradients in cell phenotypes, extracellular matrix composition, mineral content, and mechanical properties. This functional grading allows for effective transfer of stress between two materials, tendon and bone, with vastly different mechanical properties. The enthesis is formed by a pool of cells during fetal and early postnatal development that is unique from tendon and cartilage precursors. We previously defined the lineage of these Gli1+ enthesis stem cells (ESCs) and showed that initiation and mineralization of the enthesis requires hedgehog (Hh) signaling. Despite this work, the transcriptional network that controls ESC differentiation remains elusive. A better understanding of the developmental cues necessary for enthesis formation, and mineralization in particular, will help guide new stem cell treatment approaches for adult tendon- to-bone repair. Aim 1 will determine the transcriptional regulation of enthesis stem cell differentiation. Gli1- CreERT-mTmG mice will be used to isolate enthesis cells from different developmental stages and scRNAseq will be used to define their transcriptomes. The transcription factors Klf2/4 and Runx1 will be examined as putative regulators of ESC differentiation and mineralization. Aim 2 will determine the necessity and sufficiency of Gli1+ enthesis stem cells for enthesis regeneration. Healing will be evaluated using our mouse rotator cuff tendon enthesis injury model. The necessity of Gli1+ enthesis stem cells and Hh signaling for regeneration will be tested using cell ablation and loss-of-function models, respectively. The sufficiency of Gli+ enthesis stem cells and Hh signaling for regeneration will be tested by delivery of these cells to enthesis injuries and using gain-of-function models, respectively. These studies will identify the molecular mechanisms by which progenitor cells form and mineralize the enthesis. Results will have a direct impact on future regenerative strategies for tendon-to-bone repair.

摘要/摘要 肌腱损伤通常发生在其骨骼附着处附近，需要手术修复肌腱与骨骼之间的关系。结果 然而，修复后的皮肤质量很差，会导致疼痛、再次受伤和反复手术。肩袖修复术，用于 例如，是最常见的肩部手术之一，但失败率为20%-94%。在…的根源上 这些不良的结果是缺乏连接健康的特殊组织--齿端的再生 肌腱和骨头。与肌腱到骨骼愈合过程中形成的杂乱无章的疤痕相比，健康的 在细胞表型、细胞外基质组成、矿物质含量和 机械性能。该功能分级允许在两种材料之间有效地传递应力， 肌腱和骨骼，具有非常不同的机械性能。末端由一池细胞在过程中形成。 胎儿和出生后早期的发育，这是肌腱和软骨前体所独有的。我们之前 明确了这些Gli1+成体干细胞(ESCs)的谱系，并表明 末端需要刺猬(HH)信号。尽管如此，控制ESC的转录网络 区分仍然难以捉摸。更好地理解成虫所需的发育线索 形成，特别是矿化，将有助于指导成人肌腱的新干细胞治疗方法- 去骨修复。目的1将决定成体干细胞分化的转录调控。Gli1- CreERT-mTmG小鼠将用于分离不同发育阶段的生殖细胞和scRNAseq 将被用来定义他们的转录本。转录因子KLF2/4和RUNX1将被检测为 可能是ESC分化和成矿的调节因子。目标2将确定必要性和充分性 Gli1+成虫干细胞用于成虫再生。愈合情况将使用我们的鼠标肩袖进行评估 肌腱端部损伤模型。Gli1+成体干细胞和HH信号对再生的必要性 分别使用细胞消融和功能丧失模型进行测试。Gli+宿根的充分性 用于再生的细胞和HH信号将通过将这些细胞输送到末端损伤和使用 分别建立了函数增益模型。这些研究将确定分子机制，通过 祖细胞形成并矿化末端。结果将对未来的再生产生直接影响 肌腱到骨骼修复的策略。