COLLAGEN IN OSTEOARTHRITIC CARTILAGE

已有研究表明，兔的表型表达 关节软骨细胞可以通过持续的 传代培养或用维甲酸处理原代软骨细胞 酸，通过胶原蛋白表型的变化来监测。虽然 这两种调制的表型不同，都可以通过治疗逆转。 用微丝修饰药物二氢细胞松弛素B， 建议了一种共同的机制来重新表达 软骨细胞表型，我们将研究这种可能性 微丝结构中的修饰是物理传输的：ED 通过细胞骨架-核基质进入细胞核 相互作用，并导致基因表达的变化，以及 修饰可能产生化学信号的可能性 通过改变膜结合和磷酸化来介导 蛋白激酶C或酪氨酸激酶。 将对多种过程和分子关联进行测试 参与微丝机制。建筑的改动 将研究细胞蛋白质的区隔 使用高分辨率的二维蛋白质图谱技术。单克隆 针对细胞骨架蛋白的抗体将用于他们的 鉴定和量化。细胞的分布和分布 细胞骨架/核基质组件的体系结构模式 还将使用间接免疫荧光和 透射电子显微镜。将进行交联度分析 用于识别肌动蛋白和DNA相关蛋白，两者都可以 确定细胞核内是否存在肌动蛋白和 研究蛋白质的变化，这些蛋白质可能参与了 重新表达的机制。更多的研究将测试这种作用 多聚ADP核糖化，DNA超螺旋，以及对 在重新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，以了解 并操纵骨性关节炎的发病机制。开发一种 理解表型变化的机制，使用这个 独特的机型系统，将大大提升未来的机率 自然控制点的临床干预。

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.