IN VITRO CHONDROGENESIS OF BONE MARROW MESENCHYMAL CELLS

软骨分化是一个复杂的，不完全理解的过程。 我们实验室开发的培养系统促进了软骨形成， 哺乳动物骨髓间充质细胞的分化 祖细胞我们假设这个体外过程重演了 它发生在体内，它可以用来定义分子 软骨形成过程中重要的事件。第一 具体目标是检查系统的细胞生物学;包括 参与该过程的细胞的数量和类型，定量 增殖和细胞死亡的发生， 细胞在这个过程的后期。第二个具体目标是 确定特定细胞外信号表达的时间顺序， 在分化过程中产生的基质分子，作为分期的手段， 过程大多数体外骨骼发生的研究都涉及添加 作为一种手段来定义它们的功能。我们假设 通过鉴定细胞内的细胞因子， 文化系统，并确定其上升或下降的顺序， 通过监管，我们将能够更准确地定义 软骨细胞分化中的细胞因子。因此第三 具体目的是确定内源性细胞因子的时间序列， 软骨形成过程中的诱导和抑制。使用 有针对性的RNA指纹将允许筛选和识别 细胞因子家族中的特定因子， 参与软骨形成。所获得的信息可用于 应用，例如开发操作骨髓的策略， 间充质细胞，以促进软骨修复。该系统还可以被 用于检测人类基因突变对分子的影响 在软骨形成中发挥作用。

Cartilage differentiation is a complex, incompletely understood process. A culture system developed in our laboratory facilitates the chondrogenic differentiation of postnatal mammalian bone marrow-derived mesenchymal progenitor cells. We hypothesize that this in vitro process recapitulates that which occurs in vivo and that it can be used to define the molecular events that are important in the process of chondrogenesis. The first specific aim is to examine the cell biology of the system; including the number and type of cells that take part in the process, quantification of the proliferation and cell death that occurs and the commitment of cells in the later stages of the process. The second specific aim is to define the temporal sequence for the expression of specific extracellular matrix molecules produced during differentiation, as a means to staging the process. Most studies of skeletogenesis in vitro involve the addition of cytokines as a means to defining their functions. We hypothesize that by identifying the cytokines that are intrinsic to the cells in the culture system, and defining the sequence of their up- or down- regulation, we will be able to more accurately define the functions of the cytokines in chondrocyte differentiation. Therefore, the third specific aim is to define the temporal sequence of endogenous cytokine induction and repression during the process of chondrogenesis. The use of targeted RNA fingerprinting will allow screening and identification of specific factors which are within cytokine families known to be involved in chondrogenesis. The information gained may then be used for applications such as developing strategies for manipulating marrow mesenchymal cells to facilitate cartilage repair. The system may also be used for examining the effects of human genetic mutations in molecules that play a role in chondrogenesis.