Defining the Progenitor Population in Adult Zebrafish Jaw Bone Regeneration

定义成年斑马鱼颌骨再生中的祖细胞群

• 批准号: 9124158
• 负责人: Dion Giovannone
• 金额: $ 4.44万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-10 至 2019-03-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9124158
• 关键词: Ablation; Adult; Autologous Transplantation; Basic Science; Bone Development; Bone Injury; Bone Regeneration; Bone Transplantation; Bone callus; Candidate Disease Gene; Cartilage; Cell Cycle Progression; Cell Proliferation; Cell Therapy; Cells; Chondrocytes; Clinical; Color; Data; Event; Excision; Fishes; Fracture; Future; Gene Expression Profile; Genes; Genetic; Healed; Homeostasis; Human; Immune response; Immune system; Immunology; In Situ Hybridization; Inflammatory Response; Injury; Intervention; Jaw; Knowledge; Lead; Mammals; Mechanics; Messenger RNA; Modeling; Molecular; Monitor; Mus; Natural regeneration; Orthopedic Surgery procedures; Osteoblasts; Pathway interactions; Patients; Periosteal Cell; Periosteum; Population; Proliferating; Property; Recruitment Activity; Role; Signal Pathway; Signal Transduction; Site; Source; Staging; Stem cells; Testing; Therapeutic; Therapeutic Intervention; Transgenes; Transgenic Organisms; Work; Zebrafish; base; bone; cartilage repair; craniofacial; deep sequencing; defined contribution; genetic profiling; healing; in vivo imaging; insight; macrophage; man; mimicry; mouse model; nerve stem cell; next generation sequencing; novel; progenitor; public health relevance; regenerative; repaired; research study; response

 DESCRIPTION (provided by applicant): Approximately 8 million bone fractures occur annually and 10% of these are delayed and nonunion fractures which fail to heal despite therapeutic intervention. Current therapeutic strategies are severely hindered by the limited supplies of autograft bone and the poor mechanical properties of artificial materials. Zebrafish are masters of regeneration, and I have found that adult zebrafish can rapidly regenerate up to half of its lower jawbone after resection. Craniofacial bone development is highly conserved between zebrafish and humans, and hence understanding large-scale bone regeneration in zebrafish may lead to novel treatments in patients. A unique feature of zebrafish jawbone regeneration is the involvement of an unusual bone-producing chondrocyte population. In this application, I aim to identify the progenitor population that generates these ossifying chondrocytes during large-scale bone regeneration, as well as the role of macrophages in stimulating this progenitor population. Utilizing Cre-based transgenic lineage tracing strategies, I will test that a Runx2+/Sp7- population of pre-osteolasts in the periosteum generate the cartilage callus during regeneration. Using a genetic ablation strategy, I will then test that macrophages are required for the earliest events in bone repair, namely the shift of periosteal cells from making bone during homeostasis to making cartilage during repair. Lastly, I propose to utilize a RUNX2:GFP transgene to isolate these periosteal cells for deep sequencing of expressed mRNAs, which will help identify macrophage-dependent genes activated in periosteal cells after injury. Together, positive findings will illuminate the role of the immune system in shifting the fate of periosteal cells from bone to cartilage during bone repair, with knowledge gained in the zebrafish model being used in the future to develop new bone repair strategies in patients.

 描述（由申请人提供）：每年大约发生 800 万例骨折，其中 10% 是迟发性骨折和骨不连骨折，尽管经过治疗干预仍无法愈合。目前的治疗策略受到自体移植骨供应有限和人造材料机械性能较差的严重阻碍。斑马鱼是再生大师，我发现成年斑马鱼切除后可以迅速再生多达一半的下颌骨。斑马鱼和人类的颅面骨发育高度保守，因此了解斑马鱼的大规模骨再生可能会为患者带来新的治疗方法。斑马鱼颌骨再生的一个独特特征是涉及不寻常的骨生成软骨细胞群。在此应用中，我的目标是确定在大规模骨再生过程中产生这些骨化软骨细胞的祖细胞群，以及巨噬细胞在刺激该祖细胞群中的作用。利用基于 Cre 的转基因谱系追踪策略，我将测试骨膜中的 Runx2+/Sp7- 前成骨细胞群在再生过程中生成软骨愈伤组织。然后，我将使用基因消融策略来测试骨修复中最早的事件是否需要巨噬细胞，即骨膜细胞从稳态期间制造骨骼转变为修复期间制造软骨的转变。最后，我建议利用 RUNX2:GFP 转基因分离这些骨膜细胞，对表达的 mRNA 进行深度测序，这将有助于识别损伤后骨膜细胞中激活的巨噬细胞依赖性基因。总之，积极的发现将阐明免疫系统在骨修复过程中将骨膜细胞的命运从骨转变为软骨的作用，从斑马鱼模型中获得的知识将来可用于为患者开发新的骨修复策略。