COLLAGEN IN OSTEOARTHRITIC CARTILAGE

已经表明，兔的表型表达 关节软骨细胞可以通过持续的调节来调节 传代培养或用维甲酸处理原代软骨细胞 酸，如通过胶原蛋白表型的变化监测的。 虽然 两种调节的表型不同，两者都可以通过治疗逆转， 使用微丝修饰药物二氢细胞松弛素B， 这表明了一种共同的机制， 软骨细胞表型，我们将调查的可能性， 微丝结构的改变是物理传递的：艾德 进入细胞核，通过细胞质-核基质 相互作用，并导致基因表达的变化， 修饰可能产生化学信号的可能性 介导的改变膜协会和磷酸化， 蛋白激酶C或酪氨酸激酶。 将测试多个过程和分子关联， 参与微丝机制。 的改变 将研究细胞蛋白质的区室化 使用高分辨率二维蛋白质图谱技术。 单克隆 针对细胞骨架蛋白的抗体将被用于其 鉴定和定量。 细胞分布和 细胞骨架/核基质成分的结构模式 还将使用间接免疫荧光进行研究， 透射电子显微镜 交联分析将是 用于鉴定肌动蛋白和DNA相关蛋白，两者都 确定细胞核内存在或不存在肌动蛋白， 研究可能与癌症相关的蛋白质变化， 再表达机制。 更多的研究将测试这种作用 多聚ADP核糖基化，DNA超螺旋，以及 再表达机制中的血清衍生因子。 拟议的研究是长期战略的一部分， 并控制骨关节炎的发病机制。 开发一个 了解表型变化的机制，使用这种 独特的模型系统，将大大提高未来的概率 在自然控制点进行临床干预。

It has been shown that the phenotypic expression of rabbit articular chondrocytes may be modulated either by continued subculture or by treatment of primary chondrocytes with retinoic acid, as monitored by changes in the collagen phenotype. Although the two modulated phenotypes differ, both are reversed by treatment with the microfilament modifying drug dihydrocytochalasin B, suggesting a common mechanism for the reexpression of the chondrocyte phenotype, we will investigate the possibility that modifications in microfilament structure are physically transmit:ed into the nucleus, by way of cytoskeletal-nuclear matrix interactions, and result in changes in gene expression, and the possibility that modification may generate chemical signals mediated by altered membrane association and phosphorylation by protein kinase C or tyrosine kinases. Multiple processes and molecular associations will be tested for involvement in the microfilament mechanism. Alterations in the compartmentalization of cellular proteins will be investigated using high resolution 2-D protein mapping techniques. Monoclonal antibodies to cytoskeletal proteins will be used in their identification and quantitation. The cellular distribution and architectural patterns of cytoskeletal/nuclear-matrix component will also be investigated using indirect immunofluorescence and transmission electron microscopy. Crosslinking analysis will be used to identify both actin- and DNA-associated proteins, both to establish the presence or absence of actin within the nucleus and to study changes in proteins that are likely to be involved in the mechanism of reexpression. Additional studies will test the role of poly-ADP ribosylation, DNA supercoiling, and the requirement for a serum-derived factor in the reexpression mechanism. The proposed studies are part of a long term strategy to understand and manipulate the pathogenesis of osteoarthritis. Developing an understanding of the mechanisms of phenotypic change, using this unique model system, will greatly enhance the probability of future clinical intervention at natural control points.