In vivo two-photon imaging of vascular invasion and stem cell translocation in calvarial bone

颅骨血管侵袭和干细胞易位的体内双光子成像

• 批准号: 10603163
• 负责人: Andy Y Shih
• 金额: $ 29.54万
• 依托单位: SEATTLE CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10603163
• 关键词: Address; Adult; Blood Vessels; Bone Development; Bone Marrow; Bone Regeneration; Bone Tissue; Bone remodeling; Calvaria; Cartilage; Cell Lineage; Cells; Defect; Development; Developmental Process; Distant; Embryonic Development; Endothelial Cells; Esthetics; Fluorescent Dyes; Future; GLI gene; Goals; Histologic; Homeostasis; Iatrogenesis; Image; Injury; Intravenous; Invaded; Knowledge; Label; Maintenance; Mesenchyme; Molecular; Mus; Natural regeneration; Osteoblasts; Osteoclasts; Osteogenesis; Pericytes; Periosteum; Physiologic Ossification; Population; Regulation; Reporter; Research; Research Project Grants; Research Proposals; Site; Skeleton; Surgical sutures; Tamoxifen; Techniques; Testing; Time; Transgenic Mice; Trauma; Vascularization; Visualization; analog; bone; bone healing; bone repair; cell behavior; congenital anomaly; cortical bone; craniofacial development; healing; in vivo imaging; in vivo two-photon imaging; injured; injury and repair; intramembranous bone formation; long bone; novel therapeutic intervention; osteoclastogenesis; postnatal; postnatal development; regenerative; serial imaging; skeletal stem cell; stem cell niche; stem cells; substantia spongiosa; two-photon

PROJECT SUMMARY Calvarial bone defects commonly occur as a result of trauma, congenital anomalies and iatrogenic conditions. The healing of bone defects relies on the regenerative capability of calvarial bones to replace damaged bone tissues and the availability of skeletal stem cells (SSCs) is one of the key factors for generating new bones to restore both structural and functional integrity. Calvarial SSCs that express marker gene Gli1, Axin2 or Prx1 reside in the sutural stem cell niche and contribute to calvarial bone homeostasis and healing after injury. It remains unclear how calvarial SSCs translocate from the sutural niche to distant regions of the calvarial bones for bone repair after injury of sites remote to the suture. Our preliminary analysis through 2-photon imaging indicates that Gli1-expressing calvarial SSCs not only reside in the sutural niche but also line the walls of blood vessels distributed widely throughout the postnatal calvarial bones. In this project, we will test the hypothesis that calvarial SSCs in the sutural niche could translocate with vascular invasion that initiates at the postnatal suture, and could reside within calvarial bones to contribute to bone regeneration after injury. We propose two specific aims for this project: 1) Determine if vascular invasion from the suture results in bone marrow cavity formation in postnatal calvarial bones, and 2) Determine if calvarial SSCs in the sutural niche translocate with vascular invasion to establish the SSC niche in bone marrow cavities of postnatal calvarial bones. This research proposal leverages the unique expertise of two investigative labs to address a key gap in our knowledge of calvarial healing. Successful completion of this exploratory research will set the stage for further mechanistic studies such as molecular regulation of calvarial SSC translocation, which could facilitate the development of new therapeutic approaches for rapid bone regeneration after injury.

项目摘要 颅骨缺损通常是由于创伤、先天性畸形和医源性疾病造成的。 骨缺损的愈合依赖于颅骨的再生能力，以取代受损的骨 组织和骨骼干细胞（SSC）的可用性是产生新骨的关键因素之一， 恢复结构和功能的完整性。表达标记基因Gli1、Axin2或Prx1的颅骨SSCs 存在于缝干细胞龛中，并有助于颅骨骨稳态和损伤后的愈合。它 目前尚不清楚颅骨干细胞是如何从骨缝处转移到颅骨远端区域的 用于缝合线远端部位损伤后的骨修复。我们通过双光子成像的初步分析 表明Gli1表达的颅骨SSCs不仅存在于骨缝龛中，而且还排列在血液壁中， 血管广泛分布于出生后的颅骨。在这个项目中，我们将测试假设 颅缝龛中的SSCs可以随着出生后开始的血管侵入而移位， 缝合，并可驻留在颅骨内，以促进损伤后的骨再生。我们提出了两 本项目的具体目的：1）确定缝线是否会导致血管侵入骨髓腔 在出生后的颅骨形成，和2）确定是否颅骨SSCs在缝龛易位与 血管侵入，以在出生后颅骨的骨髓腔中建立SSC龛。这 研究提案利用两个调查实验室的独特专业知识，以解决我们在 关于颅骨愈合的知识这项探索性研究的成功完成将为进一步研究奠定基础。 机制研究，如颅顶SSC易位的分子调控，这可能有助于 开发新的治疗方法，用于损伤后快速骨再生。