Fetal Stromal Progenitor Cells in Mice

描述（由申请人提供）： 我们目前对间充质干细胞（MSC）生物学的了解大多来自成人组织来源。MSC生物学的发育方面仍然相对未知。然而，了解MSC样群体的个体发育及其在正常发育中的作用可能为MSC的出生后鉴定，功能表征和最终临床利用提供重要见解。本申请的长期目标是将从产前间充质祖细胞群体的分离、表征和分析中获得的见解应用于开发临床有用的出生后MSC群体的目标。本申请的具体目的是：1）完成小鼠模型中胎儿多能基质祖细胞群的体外表征。我们已经从胎儿肝脏、胎儿骨髓和脐带血中分离出独特的鼠胎儿多能基质祖细胞（fMSP），并开始对其进行鉴定。我们假设一个共同的fMSP存在于发育中的胎儿在多个组织。为此，将对每个fMSP群体的体外生长特征、克隆扩增、多能性、支持造血的能力和胚胎细胞标志物的表达进行充分表征和比较。2)明确小鼠多能间质祖细胞的发育个体发生。我们假设fMSP在胎儿中有一个共同的起源部位，并在发育过程中迁移到造血和非造血组织。为了解决这一假设，我们将尝试在主动脉-性腺-中肾区、胎儿肝脏和胎儿骨髓中造血发生之前和同时从胎儿的特定造血和非造血区域分离fMSP。3)在小鼠子宫内干细胞移植模型中评估胎儿多能间质祖细胞的体内情况。我们将使用我们实验室开发的用于腹膜内或血管内胎儿注射的技术将转基因GFP/雄性fMSP的优化群体移植到胎儿受体中。我们将研究归巢，短期和长期的植入，并在体内多潜能的fMSP在相对不受干扰的环境中的胎儿模型。这些研究应该提高我们对间充质祖细胞的发育生物学的理解，并且应该导致更好地理解它们在正常组织重塑和成熟中的生理作用，以及最终，它们在组织修复和再生中响应损伤或疾病的作用（如果有的话）。

DESCRIPTION (provided by applicant): Most of our current knowledge of mesenchymal stem cell (MSC) biology derives from adult tissue sources. The developmental aspects of MSC biology remain relatively unknown. Yet it is likely that understanding the ontogeny of MSC like populations and their role in normal development can provide important insights toward the postnatal identification, functional characterization, and ultimately the clinical utilization of MSCs. The long-term objective of this application is to apply insights gained from the isolation, characterization, and analysis of prenatal mesenchymal progenitor populations toward the goal of developing clinically useful postnatal MSC populations. The specific aims of this application are: 1) To complete the in vitro characterization of fetal multipotent stromal progenitor populations in the murine model. We have isolated and begun to characterize unique populations of murine fetal multipotent stromal progenitor (fMSP) cells from fetal liver, fetal bone marrow, and cord blood. We hypothesize that a common fMSP exists in the developing fetus in multiple tissues. In this aim, each fMSP population will be fully characterized and compared with respect to in vitro growth characteristics, clonal expansion, multipotentiality, ability to support hematopoiesis, and expression of embryonal cell markers. 2) To define the developmental ontogeny of murine multipotent stromal progenitors. We hypothesize that fMSPs have a common site of origin in the fetus and migrate to hematopoietic and non-hematopoeitic tissues during development. To address this hypothesis, we will attempt to isolate fMSPs from specific hematopoietic and non-hematopoietic regions of the fetus prior to, and concurrent with, onset of hematopoiesis in the Aorto-Gonadal-Mesonephric region, fetal liver, and fetal bone marrow. 3) To assess fetal multipotent stromal progenitors in vivo in the murine in utero stem cell transplantation model. We will transplant optimized populations of transgenic GFP/male fMSPs into fetal recipients using techniques developed by our laboratory for intraperitoneal, or intravascular fetal injection. We will investigate homing, short and long term engraftment, and in vivo multipotentiality of fMSPs in the relatively unperturbed milieu of the fetal model. These studies should improve our understanding of the developmental biology of mesenchymal progenitors and should lead to a better understanding of their physiologic role in normal tissue remodeling and maturation and ultimately, what role, if any, they play in tissue repair and regeneration in response to injury or disease.