Rapid mobilization of endogenous progenitor cells for bone healing

快速动员内源性祖细胞促进骨愈合

• 批准号: 8301916
• 负责人: Clare E Yellowley-Genetos
• 金额: $ 17.31万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8301916
• 关键词: AMD3100; Acute myocardial infarction; Age; Anti-Inflammatory Agents; Anti-inflammatory; Biomechanics; Bone Marrow; Bone Marrow Aspiration; Bone Regeneration; Bone callus; CSF3 gene; CXCR4 Receptors; Cartilage; Cell Count; Cell Differentiation process; Cell Separation; Cells; Collection; Colony-Forming Units Assay; Complex; Complication; Deformity; Disease; Engraftment; Flow Cytometry; Fracture; Fracture Healing; General Anesthesia; Goals; Granulocyte Colony-Stimulating Factor; Growth Factor; Healed; Hematopoietic Stem Cell Mobilization; Hematopoietic stem cells; Home environment; Homing; Impaired wound healing; In Vitro; Inflammatory; Injury; Intervention; Label; Laboratories; Life Style; Ligaments; Measures; Mechanics; Mesenchymal Stem Cells; Minerals; Modeling; Molecular; Mus; Musculoskeletal; Myocardial; Natural regeneration; Osteogenesis; Pain; Pharmaceutical Preparations; Population; Process; Recovery; Shapes; Signal Transduction; Site; Smoking; Source; Stem cells; Stromal Cell-Derived Factor 1; Tendon structure; Testing; Therapeutic; Time; Tissues; Transplantation; Vascular Endothelial Growth Factors; Work; angiogenesis; base; body system; bone; bone healing; cell motility; cell preparation; chemokine; cost effective; cytokine; density; effective therapy; healing; improved; in vivo; mortality; paracrine; peripheral blood; progenitor; receptor; repaired; response; scaffold; stem; tissue regeneration

DESCRIPTION (provided by applicant): Impaired healing and non-union are a serious complication of a fracture that results in pain, deformity, diminished function and mobility. Bone healing is a complex process which requires stem and progenitor cell migration to repair the vasculature, establish a callus and ultimately return the bone to its former shape and mechanical integrity. Delivery of bone marrow derived stem and progenitor cells to the site of injury is an effective therapy to enhance healing. Bone marrow is a rich source of endothelial progenitor cells (EPCs), mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs), which have been shown to induce angiogenesis and osteogenesis and release anti-inflammatory cytokines to enhance bone healing. However, cell-based therapeutics such as these require the isolation of bone marrow and expansion or concentration of cells in vitro. A radically different approach is to rapidly mobilize large numbers of endogenous progenitor cells directly into the peripheral blood (PB) that will home to the site of injury and take part in tissu regeneration. AMD3100, is a selective antagonist of chemokine (CXC motif) receptor 4 (CXCR4) that rapidly mobilizes HSCs and EPCs into PB. AMD3100 in combination with VEGF mobilizes MSCs. Our central hypothesis is that bone marrow-derived progenitor cells are released into the PB subsequent to fracture, and that increasing circulating numbers of these cells using pharmacological interventions will improve bone healing. We will test this hypothesis a) by quantifying MSCs, HSCs and EPCs mobilized in response to fracture and AMD3100/VEGF in the mouse using colony forming unit assays and flow cytometry; b) by tracking the homing of mobilized progenitor cells to the fracture site; c) by measuring the effects of VEGF/AMD3100 on bone healing using a murine fracture model. We propose to mobilize cells during the first three days of fracture healing, at a time when inflammatory cytokines and chemoattractant molecules are released, and cells are thought to home to the site of injury. We anticipate that fracture results in increased numbers of MSCs, HPCs and EPCs in PB and that pharmacological intervention can significantly increase these numbers further. We anticipate that early, increased availability of circulating progenitor cells to home to the fracture site and contribute directly to tissue healing by engraftment, cell differentiation and tissue elaboration o indirectly through release of paracrine factors will accelerate bone healing. Enhanced healing will be evidenced by a greater callus size, tissue mineral density, and biomechanical strength. Our overall objective is to show that rapid release of endogenous bone marrow progenitors into PB is an effective strategy to enhance tissue regeneration. It is expected that efficient mobilization of stem cells shortly after injury, could circumvent the need for bone marrow aspiration, and complications associated with in vitro cell manipulation. PUBLIC HEALTH RELEVANCE: Rapid pharmacological mobilization of endogenous cell populations into PB, as an effective strategy to enhance tissue regeneration, would circumvent current complications associated with progenitor cell isolation, in vitro manipulation and subsequent delivery. This has significant implications for our current cell based strategies for bone regeneration, and could be extended as a simple and cost effective therapy for the treatment of damage in other musculoskeletal tissues such as cartilage, ligament and tendon, and beyond bone for the repair of other organ systems.

描述（由申请人提供）：愈合不良和骨不连是骨折的严重并发症，可导致疼痛、畸形、功能和活动度下降。骨愈合是一个复杂的过程，需要干细胞和祖细胞迁移以修复血管系统，建立愈伤组织并最终使骨恢复其先前的形状和机械完整性。将骨髓源性干细胞和祖细胞递送至损伤部位是促进愈合的有效疗法。骨髓是内皮祖细胞（EPC）、间充质干细胞（MSC）和造血干细胞（HSC）的丰富来源，其已被证明诱导血管生成和成骨并释放抗炎细胞因子以促进骨愈合。然而，诸如这些的基于细胞的治疗剂需要分离骨髓并在体外扩增或浓缩细胞。一种完全不同的方法是快速动员大量的内源性祖细胞直接进入外周血（PB），这些细胞将回到损伤部位并参与组织再生。AMD 3100是趋化因子（CXC基序）受体4（CXCR 4）的选择性拮抗剂，可快速动员HSC和EPC进入PB。AMD 3100与VEGF联合动员MSC。我们的中心假设是，骨髓来源的祖细胞在骨折后释放到PB中，并且使用药物干预增加这些细胞的循环数量将改善骨愈合。我们将检验这一假设：a）通过使用集落形成单位测定和流式细胞术定量小鼠中响应骨折和AMD 3100/VEGF而动员的MSC、HSC和EPC; B）通过追踪动员的祖细胞归巢到骨折部位; c）通过测量 VEGF/AMD 3100对骨愈合的影响。我们建议在骨折愈合的前三天动员细胞，此时炎性细胞因子和化学引诱物分子被释放，细胞被认为是受伤部位的家。我们预期骨折导致PB中MSC、HPC和EPCs数量增加，并且药物干预可以进一步显著增加这些数量。我们预计，早期，增加循环祖细胞的可用性，以家庭骨折部位， 通过植入、细胞分化和组织加工直接促进组织愈合，或通过旁分泌因子的释放间接促进骨愈合。愈伤组织尺寸、组织矿物质密度和生物力学强度的增加将证明愈合增强。我们的总体目标是显示内源性骨髓祖细胞快速释放到PB中是增强组织再生的有效策略。预期在损伤后不久干细胞的有效动员可以避免骨髓抽吸的需要以及与体外细胞操作相关的并发症。 公共卫生相关性：作为增强组织再生的有效策略，将内源性细胞群快速药理学动员到PB中将避免与祖细胞分离、体外操作和随后递送相关的当前并发症。这对我们目前基于细胞的骨再生策略具有重要意义，并且可以扩展为一种简单且具有成本效益的治疗方法，用于治疗其他肌肉骨骼组织（如软骨、韧带和肌腱）以及骨以外的其他器官系统的修复。