Cellular and Molecular Mechanisms of Murine Digit Regeneration

小鼠手指再生的细胞和分子机制

• 批准号: 9889795
• 负责人: Feini Qu
• 金额: $ 6.01万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9889795
• 关键词: Ablation; Adult; Affect; American; Amphibia; Amputation; Amputees; Attenuated; Beds; Bioinformatics; Biological; Bone Regeneration; Cell Lineage; Cell Proliferation; Cells; Complex; Cues; Devices; Differentiation Antigens; Digit structure; Disease; Distal; Epithelial; Epithelium; Event; Excision; Failure; Fluorescent in Situ Hybridization; Ganciclovir; Growth; Growth Factor; Human; In Situ Hybridization; Investigation; Label; Limb structure; Mammals; Mediating; Mesenchymal; Methods; Modeling; Molecular; Molecular Target; Mus; Musculoskeletal; Nail plate; Natural regeneration; Organ; Osteoblasts; Paracrine Communication; Pathway interactions; Patient-Focused Outcomes; Periosteal Cell; Periosteum; Play; Population; Process; Production; Proliferating; Proliferation Marker; Prosthesis; Quality of life; RNA; Regenerative Medicine; Regenerative response; Regulator Genes; Regulatory Pathway; Rehabilitation therapy; Reporter; Research Personnel; Role; Signal Transduction; Source; Structure; Technology; Testing; Tissues; Training; Transgenic Mice; Transgenic Organisms; Translating; Trauma; WNT Signaling Pathway; Work; beta catenin; bioinformatics tool; blastema; bone; career development; cell growth; cell type; conditional knockout; cost; digit regeneration; improved; innovation; insight; laser capture microdissection; limb regeneration; microCT; mouse model; musculoskeletal injury; novel therapeutics; osteogenic; outcome forecast; paracrine; regenerative; response; skeletal disorder; skeletal injury; skills; spatiotemporal; stem; stem cells; transcriptome sequencing; transcriptomics

Project Summary Humans have limited regenerative potential after extensive musculoskeletal injuries, particularly following limb loss. As such, the ability to biologically restore the missing limb will significantly improve the quality of life for millions of amputees. To understand the fundamental mechanisms guiding regeneration of complex musculoskeletal tissues or organs, mouse models of digit amputation have been used to study musculoskeletal regrowth, which occurs in a spatiotemporally controlled manner upon distal digit tip removal. While much progress has been made to elucidate the cell types and growth factors responsible for this natural regenerative response, the exact cellular and molecular mechanisms underlying digit regeneration have yet to be revealed. Recent studies suggest that cells derived from the periosteum participate in bone regrowth in adults, and thus represent a possible source of osteoblast lineage cells. However, it remains unknown to what extent this specific cell population plays a direct role in digit regeneration. We hypothesize that spatiotemporal activation of distinct molecular events after distal digit amputation mediates the activation, proliferation, and/or differentiation of periosteal cells (PCs). To test this hypothesis, we will investigate the spatiotemporal response of PCs after digit amputation using Osx-CreERT2;Ai9 inducible reporter transgenic mice in Aim 1, which will permit lineage tracing of this cell population. Furthermore, we will test the requirement of proliferating PCs during digit regeneration by inducible conditional ablation of replicating PCs using 3.6Col1a1-tk transgenic mice. Finally, we will determine the signaling cues that activate and sustain digit regeneration in Aim 2 using RNA in situ hybridization and tissue-specific RNA-sequencing, with a specific focus on the spatiotemporal distribution of canonical Wnt signaling. By identifying the cells and molecular pathways vital to regeneration, this proposal will open new avenues to therapies that will help restore the biological composition and structure of the lost tissues.

项目摘要 人类在广泛的肌肉骨骼损伤后再生潜力有限， 失去肢体后因此，在生物学上恢复缺失肢体的能力将显著改善患者的生活质量。 数百万截肢者的生活质量。为了了解指导再生的基本机制， 复杂的肌肉骨骼组织或器官，手指截肢的小鼠模型已被用于研究 肌肉骨骼再生，这发生在时空控制的方式后，远端指尖去除。 虽然已经取得了很大的进展，以阐明细胞类型和生长因子负责这一自然的， 再生反应，确切的细胞和分子机制的数字再生还没有 被揭露。最近的研究表明，来源于骨膜的细胞参与骨再生， 成人，因此代表成骨细胞谱系细胞的可能来源。然而，它仍然是未知的， 这种特殊的细胞群在手指再生中起着直接的作用。 我们假设远端断指后不同分子事件的时空激活 介导骨膜细胞（PC）的活化、增殖和/或分化。为了验证这个假设，我们 将使用Osx-CreERT 2; Ai 9诱导型研究手指截肢后PC的时空反应 报告基因转基因小鼠，这将允许该细胞群的谱系追踪。此外，我们将 通过诱导条件性复制消融试验， 使用3.6Col1a1-tk转基因小鼠的PC。最后，我们将确定激活和维持 使用RNA原位杂交和组织特异性RNA测序，在Aim 2中进行手指再生， 集中于经典Wnt信号传导的时空分布。通过识别细胞和分子 对于再生至关重要的途径，这一建议将开辟新的途径，以治疗，这将有助于恢复 失去的组织的生物组成和结构。