Identifying Approaches to Enhance Bone and Cartilage Regeneration

确定增强骨和软骨再生的方法

• 批准号: 10629250
• 负责人: Louis J. Dell'Italia
• 金额: --
• 依托单位: BIRMINGHAM VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10629250
• 关键词: Affect; Apoptosis; Autologous; Biological; Biological Assay; Biology; Blood Vessels; Bone Development; Bone Morphogenetic Proteins; Bone Regeneration; Bone Transplantation; Bone callus; Bone remodeling; Cartilage; Cell Differentiation process; Cell Proliferation; Cell Survival; Cells; Cellular biology; Chondrocytes; Chondrogenesis; Clinical; Clonal Expansion; Data; Defect; Degenerative Disorder; Degenerative polyarthritis; Dental Implants; Development; Ensure; Exhibits; Failure; Fibrous capsule of kidney; Fracture; Growth; Healthcare; Hindlimb; Hip Fractures; Hydrogels; Implant; In Vitro; Individual; Industry; Injury; Knock-out; Knockout Mice; Laboratories; Mesenchymal; Methods; Micro Array Data; Modeling; Morbidity - disease rate; Mus; Natural regeneration; Operative Surgical Procedures; Orthopedic Procedures; Osteoblasts; Osteocytes; Osteogenesis; Pathway interactions; Patients; Phenotype; Physical condensation; Play; Powder dose form; Predisposition; Procedures; Process; Proteins; Publishing; Recombinants; Regenerative pathway; Replacement Arthroplasty; Research Personnel; Role; Secure; Series; Site; Skeleton; Spinal Fusion; Stimulus; Techniques; Testing; Time; Transgenic Mice; Translating; Veterans; Wild Type Mouse; aging population; bone; bone fracture repair; bone healing; bone quality; cartilage regeneration; cell type; cost; daughter cell; experimental study; healing; improved; improved outcome; in vitro Assay; in vitro testing; in vivo; in vivo Model; insight; irradiation; limb injury; migration; military veteran; mortality; novel; osteogenic; osteoprogenitor cell; progenitor; repaired; skeletal; skeletal stem cell; success; surgery outcome; targeted treatment; therapeutic target; therapy development; therapy outcome; tool; warfighter

Failure to properly heal bone fractures is associated with significant morbidity and mortality. Additionally, the need to properly form bone is vital to successful outcomes from surgeries ranging from joint replacement to spinal fusion to dental implants. In an aging population, the biomedical need is even greater. The recent identification of skeletal progenitor cells, composed of 8 subpopulations, capable of forming all three components of the skeleton, bone, cartilage and stroma, promises to have a major impact on improving the outcomes for these therapies. A key question that remains is what are the factors affecting eventual cell fate of these skeletal progenitor cells. Our data on the matricellular protein DEL1 have shown it has an impact on skeletal repair. We have preliminary data indicating that it has a direct effect on skeletal progenitor cell biology and we propose that DEL1 plays an important role in their biology. Prior to this, our data had shown DEL1 had a biological effect on chondrocytes, but not on osteoblasts. We demonstrated decreased numbers of mouse skeletal stem cells (mSSCs), and bone, cartilage, stroma progenitors (BCSPs), the skeletal progenitor most important in fracture healing in the fracture callus, and we propose the mechanism for decreased bone formation after fracture is due to an effect on skeletal progenitors ability to expand after fracture. We plan on examining this first by isolating mSSCs and BCSPs, from knockout (KO) and wild type (WT) mice and comparing their biology. We will examine the biology of BCSPs using in vitro assays for cell proliferation, osteogenic and chondrogenic potential. BCSPs develop a different phenotype termed the fracture BCSP (f-BCSP) that has greater proliferative ability and osteogenic potential after fracture, and we will test whether the same change occurs in our KO mice. We will perform in vivo assays for osteogenesis by implanting BCSPs into the renal capsule to examine how well they form bone. A key question in understanding how DEL1 affects formation of bone after fracture is to understand what happens to skeletal progenitors after fracture in WT and KO mice. We will use lineage tracing techniques with mice currently in our laboratory to examine the fate of daughter cells from individual clones of skeletal progenitors cells. The final series of experiments represent our initial approaches to translating use of DEL1 into potential therapies. First, we will perform a carefully controlled microarray experiment to identify pathways altered in KO skeletal progenitors compared to WT. We will examine the ability of exogenous DEL1 to promote viability and growth of skeletal stem cells grown in vitro. We will test the ability of DEL1 to stimulate bone and cartilage formation of skeletal progenitor cells implanted into the renal capsule. Finally, we will examine whether exogenous DEL1 protein placed at a fracture site can enhance normal fracture healing. We will also use a separate model of poor fracture healing with mice that have undergone hindlimb irradiation. In summary, we will examine how Del1 affects the biology of skeletal progenitor cells. In addition to providing steps to potentially translate these discoveries into therapies, these experiments can provide us with mechanistic answers about how lack of Del1 leads to decreased bone in fracture healing. They will provide insight into the factors that affect the potential fate of skeletal progenitor cells.

骨折未能正确愈合与显着的发病率和死亡率相关。此外， 正确形成骨骼的需要对于从关节置换到手术等手术的成功结果至关重要 脊柱融合到牙种植体。在人口老龄化中，生物医学的需求更大。最近的 鉴定骨骼祖细胞，由 8 个亚群组成，能够形成所有三种 骨骼、骨、软骨和基质的组成部分，有望对改善 这些疗法的结果。仍然存在的一个关键问题是影响细胞最终命运的因素有哪些？ 这些骨骼祖细胞。我们关于基质细胞蛋白 DEL1 的数据表明它对 骨骼修复。我们的初步数据表明它对骨骼祖细胞生物学有直接影响 我们认为 DEL1 在其生物学中发挥着重要作用。 在此之前，我们的数据表明DEL1对软骨细胞有生物学作用，但对成骨细胞没有生物学作用。我们 小鼠骨骼干细胞 (mSSC) 以及骨、软骨、基质数量减少 祖细胞（BCSP），是骨折愈伤组织中对骨折愈合最重要的骨骼祖细胞，我们 提出骨折后骨形成减少的机制是由于对骨骼祖细胞的影响 骨折后的扩张能力。我们计划首先通过从敲除中分离 mSSC 和 BCSP 来检查这一点 (KO) 和野生型 (WT) 小鼠并比较它们的生物学特性。我们将使用体外研究 BCSP 的生物学 细胞增殖、成骨和软骨形成潜力的测定。 BCSP 形成不同的表型 称为骨折BCSP（f-BCSP），骨折后具有更强的增殖能力和成骨潜力， 我们将测试同样的变化是否会发生在我们的 KO 小鼠身上。我们将进行体内测定 通过将 BCSP 植入肾囊中来检查它们形成骨的情况来进行成骨。 了解 DEL1 如何影响骨折后骨形成的一个关键问题是了解什么 WT 和 KO 小鼠骨折后骨骼祖细胞会发生这种情况。我们将使用谱系追踪技术 目前我们实验室的小鼠正在检查来自骨骼个体克隆的子细胞的命运 祖细胞。 最后一系列实验代表了我们将 DEL1 的使用转化为潜力的初步方法 疗法。首先，我们将进行仔细控制的微阵列实验，以确定 KO 中改变的途径 骨骼祖细胞与WT相比。我们将检查外源性 DEL1 促进活力和 骨骼干细胞在体外的生长。我们将测试DEL1刺激骨和软骨的能力 植入肾囊的骨骼祖细胞的形成。最后，我们将检查是否 将外源性 DEL1 蛋白置于骨折部位可以增强骨折的正常愈合。我们还将使用一个 接受后肢照射的小鼠骨折愈合不良的单独模型。 总之，我们将研究 Del1 如何影响骨骼祖细胞的生物学。此外 这些实验提供了将这些发现转化为治疗方法的步骤，可以为我们提供 关于 Del1 缺乏如何导致骨折愈合过程中骨量减少的机制答案。他们将提供 深入了解影响骨骼祖细胞潜在命运的因素。