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 肌腱损伤通常在其骨附着附近发生，需要对肌腱进行手术修复。结果 然而，修复后，较差，导致疼痛，重伤和反复手术。肩袖维修，用于 例如，是最常见的肩部手术之一，但失败率20-94％。词根 这些差的结果是缺乏源头的再生，这是连接健康的专门组织 肌腱和骨头。与在肌腱到骨愈合过程中形成混乱的疤痕相反，健康 Enthesis在细胞表型，细胞外基质组成，矿物质含量和 机械性能。这种功能分级可以有效地在两种材料之间转移应力， 肌腱和骨，具有巨大不同的机械性能。该源是由一个细胞池形成的 胎儿和早期产后发育是肌腱和软骨前体独有的。我们以前 定义了这些Gli1+伦理干细胞的谱系（ESC），并表明了起始和矿化 该渗透需要刺猬（HH）信号传导。尽管进行了这项工作，但控制ESC的转录网络 差异仍然难以捉摸。更好地理解Entingses所需的发展线索 尤其是矿化的形成，将有助于指导成人肌腱的新干细胞处理方法 骨修复。 AIM 1将确定埃文干细胞分化的转录调节。 gli1- Creert-MTMG小鼠将用于分离不同发育阶段和SCRNASEQ的细胞 将用于定义其转录组。转录因子KLF2/4和RUNX1将被检查为 ESC分化和矿化的推定调节剂。 AIM 2将决定必要和充分性 gli1+灌感干细胞的灌感再生。将使用我们的小鼠肩袖评估愈合 肌腱埃文损伤模型。 Gli1+源细胞的必要性和HH信号的再生将 分别使用细胞消融和功能丧失模型进行测试。 Gli+ Enthesis茎的充分性 细胞和HH信号的再生将通过将这些细胞递送至源头进行测试并使用 分别获得功能模型。这些研究将确定分子机制 祖细胞形成并矿化。结果将直接影响未来的再生 肌腱到骨修复的策略。