Identifying the human skeletal stem cell.

项目摘要 该计划的主要目标是鉴定和鉴定人类骨骼干细胞(HsSC)。 而且血统限制了它所产生的骨、软骨和骨髓基质组织的祖细胞。 基于我们最近在Cell上发表的详细介绍鼠标SSC的文章，我们的最终目标是创建一个详细的 人类骨骼形成的谱系图，如在造血学中所见，多能干细胞产生不同的 在一个调节分化的小生境中的血统。正如我们的小鼠研究表明的那样，我们将通过以下方式实现这一点 首先将人类骨骼干细胞和祖细胞纯化到非常高的同质性水平(目标1)，然后 然后通过检测细胞亚群的转录和翻译表达，最后 定义和探索干细胞和祖细胞之间的相互关系。因此，这些步骤将使 美国将制定战略，如何操纵SSC利基，以推动骨、软骨或骨髓的命运决定 影响临床需求的间质(目标2)。我们对MSSC利基法规的调查也导致我们发现 骨形态发生蛋白-2、Wnt和血管内皮生长因子的特异性组合可诱导骨形态发生蛋白-2和血管内皮生长因子的重新形成 SSC即使在非骨骼(脂肪)组织中也是如此。我们将探索类似的形态基因组合是否也能诱导 大量人脂肪基质中hSSC的形成和骨、软骨或基质的新生生成 人口(目标3)。 尽管老鼠模型很实用，但最近的报告描述了老鼠和人类之间的巨大差异 免疫学，这对新疗法的发展有直接影响。因此，为了真正做到 影响临床翻译，谨慎的做法是首先确定hSSC，以确定保守的关键遗传途径 并揭示小鼠和人类骨骼发生的遗传机制差异 老鼠和人类。我们相信，我们在实施MSSC战略时获得的专业知识 使我们处于一个独特的位置来表征人类对应的小鼠骨骼干细胞和祖细胞。 我们从胎儿和成人组织中获得的新的实质性初步人类骨骼干细胞/祖细胞数据 肯定我们方法在技术上的可行性，以及hssc的存在。这项计划中的实验 如果得到支持，应用将为干细胞再生医学的实际转化扫清道路 骨骼疾病。

Project Summary The primary goal of this proposed project is to identify and characterize the human skeletal stem cell (hSSC) and the lineage restricted progenitors of bone, cartilage, and bone marrow stromal tissues that it generates. Building on our recent publication in Cell detailing the mouse SSC, our ultimate objective is to create a detailed lineage map of human skeletogenesis, as seen in hematopoiesis, with a mulitpotent stem cell generating various lineages in a niche that regulates differentiation. As demonstrated in our mouse study, we will achieve this by first purifying human skeletal stem and progenitor cells to a very high level of homogeneity (Aim 1) and then secondly by examining the transcriptional and translational expression of the cellular subsets, before finally defining and probing the inter-relationship between the stem and progenitor cells. These steps will, thus, enable us to strategize how to manipulate the SSC niche to drive fate determination of bone, cartilage or bone marrow stroma to affect clinical need (Aim 2). Our investigation of the mSSC niche regulation also led us to discover specific combinations of bone morphogenetic protein-2, Wnt and VEGF that could induce de novo formation of SSC even in non-skeletal (adipose) tissue. We will explore if similar morphogen combinations could also induce hSSC formation and de novo generation of bone, cartilage, or stroma from plentiful human adipose stromal populations (Aim 3). Despite the utility of mouse models, recent reports describe dramatic differences between mouse and human immunology, which has a direct impact on the development of novel therapeutics. Therefore, in order to truly affect clinical translation, it is prudent to first identify the hSSC to identify key genetic pathways that are conserved in mouse and human skeletogenesis and to reveal the genetic mechanisms underlying differences between mouse and humans. We are confident that the expertise we acquired upon implementation of our mSSC strategy puts us in a unique position to characterize human counterparts of the mouse skeletal stem and progenitor cell. Our new substantial preliminary human skeletal stem/progenitor data from both fetal and adult tissue strongly affirm the technical feasibility of our approach and the existence of the hSSC. The proposed experiments in this application, if supported, would clear the path to practical translation of stem cell regenerative medicine for skeletal diseases.