Characterization of endogenous stem cells within endosseous wounds

描述（由申请人提供）：鉴于骨创伤、癌症以及成人和先天性疾病的高发病率，这与北美每年超过500，000例骨移植手术相关，因此骨是仅次于血液的最常见移植组织并不奇怪。除了用于缺损的传统骨移植之外，还有许多临床应用可以受益于骨再生疗法，包括颞下颌关节重建以减轻影响估计9000万美国人的颌骨疼痛，以及重建颅面骨内的轮廓和形状的恢复。间充质干细胞和祖细胞（MSPC）被认为在骨再生过程中发挥重要作用，但很少有人知道它们侵入受损或患病组织。迄今为止，还没有研究检查在骨内创伤再生过程中内源性间充质干细胞和祖细胞（MSPCs）的时空分布。这种表征对于开发依赖于这些细胞的募集的治疗策略（即，通过递送生长因子）或使用干细胞或祖细胞的外源来源。此外，植入或注射支架或水凝胶基质对MSPC迁移和分化的影响尚不清楚。在这里，我们的目标是表征以不同速率再生的缺陷内的内源性MSPC迁移和分化的时空概况，这将有助于为我们的实验室创建核心动物模型。这将用于询问涉及MSPC在受损或患病骨组织再生中的各种途径。目标1：表征非关键尺寸缺损内骨内伤口愈合期间MSPC迁移和分化的空间和时间方面。这将通过首先在体外用纯化的MSPC群体验证抗体，然后对大鼠非临界尺寸骨内缺损内的MSPC迁移和分化进行免疫组织化学分析来实现。目标2：确定在植入显著延迟骨再生的生物材料基质后内源性MSPC的时空迁移和分化是否发生变化。 公共卫生相关性：现有的颅面骨缺损（包括功能缺陷和严重美学畸形）的临床再生策略充满了许多局限性。我们的目的是表征内源性间充质干细胞和祖细胞迁移和分化的时空分布，以不同的速度再生的缺陷。这将有助于建立一个核心动物模型，我们可以用它来开发基于利用间充质干细胞再生能力的增强骨再生的新策略。

DESCRIPTION (provided by applicant): Given the high incidence of bone trauma, cancer, and adult and congenital disease, which is associated with over 500,000 bone graft procedures each year in North America, it is not surprising that bone is the most common transplanted tissue, second only to blood. In addition to traditional bone grafting for defects, there are numerous clinical applications that can benefit from bone regeneration therapies including temporomandibular joint reconstruction to alleviate jaw pain which affects an estimated 90 million Americans, and restoration of contour and shape within reconstructed craniofacial bone. Mesenchymal stem and progenitor cells (MSPCs) are believed to play an important role during bone regeneration, however very little is known regarding their invasion into damaged or diseased tissue. To date there are no studies that examine the temporal and spatial distribution of endogenous mesenchymal stem and progenitor cells (MSPCs) during endosseous wound regeneration. Such characterization may be critical to developing therapeutic strategies that rely on recruitment of these cells (i.e., via delivery of growth factors) or the use of an exogenous source of stem or progenitor cells. Additionally, the impact of implanting or injecting scaffolds or hydrogel matrices on the migration and differentiation of MSPCs is unknown. Here we aim to characterize the spatial-temporal profile of endogenous MSPC migration and differentiation within defects that regenerate at different rates that will facilitate the creation of a core animal model for our laboratory. This will be used to interrogate various pathways involving MSPCs in regeneration of damaged or diseased bone tissue. AIM 1: To characterize the spatial and temporal aspects of MSPC migration and differentiation during endosseous wound healing within non-critical size defects. This will be accomplished through first validating antibodies in vitro with purified populations of MSPCs, followed by immunohistochemical analysis of MSPC migration and differentiation within a rat non-critical sized endosseous defect. AIM 2: To determine if the spatial-temporal migration and differentiation of endogenous MSPCs changes upon implantation of biomaterial matrices which significantly delay bone regeneration. Public Health Relevance: Existing clinical strategies for regeneration of craniofacial bone defects including functional deficits and severe aesthetic deformities are fraught with many limitations. We aim to characterize the spatial-temporal profile of endogenous mesenchymal stem and progenitor cell migration and differentiation within defects that regenerate at different rates. This will facilitate the creation of a core animal model that we can use to develop new strategies for enhancing bone regeneration based on harnessing the regenerative capacity of mesenchymal stem cells.