IN VITRO CHONDROGENESIS OF BONE MARROW MESENCHYMAL CELLS

软骨分化是一个复杂的、不完全了解的过程。 我们实验室开发的培养系统促进了软骨细胞的形成 生后哺乳动物骨髓间充质细胞的分化 祖细胞。我们假设这一体外过程可以概括为 在体内发生的东西，它可以用来定义分子 在软骨形成过程中非常重要的事件。第一 具体目的是检查系统的细胞生物学；包括 参与这一过程的细胞数量和类型，量化 发生的增殖和细胞死亡，以及对 细胞在该过程的后期阶段。第二个具体目标是 确定特定细胞外基因表达的时间序列 分化过程中产生的基质分子，作为分期的手段 这一过程。大多数体外骨骼形成的研究都涉及到加法 将细胞因子作为定义其功能的一种手段。我们假设 通过识别细胞内固有的细胞因子 文化体系，并定义他们向上或向下的顺序- 规范，我们将能够更准确地界定功能 软骨细胞分化中的细胞因子。因此，第三个 具体目的是定义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。它的用途 靶向RNA指纹识别将允许筛选和识别 已知的细胞因子家族中的特定因素 参与了软骨形成。然后，所获得的信息可用于 应用程序，如开发处理骨髓的策略 间充质细胞促进软骨修复。该系统还可以 用于检测人类基因突变对分子的影响 在软骨形成过程中起着重要作用。

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.