GROWTH PLATE STUDIES IN THE CHONDRODYSTROPHIES

软骨营养不良(CDX)是一组不同类型的疾病 临床上以缩短为特征的软骨内骨生长 四肢和躯干的畸形。世界上最大规模的 导致这些疾病的致病机制很可能是 可取的，因为它不仅会导致对CDX的最终治疗， 但它将对骨骼的原因提供有价值的见解 全身畸形以及正常的骨骼生长。不幸的是， 对CDX异常的理解受到了一种 主要与获取和调查 受影响的组织，骨骼生长板。解决这些问题， 拟议的调查员已经制定了一种适合研究的方法 这些障碍。它涉及到使用高度特异的组织化学来 局部定位塑料包埋组织中的基质成分 对极少量的软骨样本进行生化分析。初步 研究表明，它作为一种手段来探索 生长板作为一种动态结构。现在建议扩大这一范围 一种系统全面检查软骨内的方法 正常对照组和CDX患者生长板组织中的骨化。 组织将通过光学和电子显微镜免疫和 凝集素组织化学、放射自显影和原位杂交。 抗基质成分的单抗：I-VI、IX(G)、X(M)和 1α，2α，3α胶原蛋白；软骨素-4-和-6-硫酸盐，角质形成 软骨的硫酸盐和透明质酸结合区亚结构 蛋白多糖；连接蛋白；纤维连接蛋白；以及特异的 将使用骨骼前胶原mRNAs。以生化方法确认 显微镜观察，软骨的微量样本对应于 软骨细胞增殖分化的不同阶段 用高效液相色谱和十二烷基硫酸钠-聚丙烯酰胺凝胶电泳法对器官培养进行了研究 同位素标记的主要和相对比例的存在和 新合成基质中的少量胶原蛋白和糖胺聚糖。这些 研究应该允许对正常事件的准确呈现 待构建的软骨内骨化及其缺损区 已确认身份。

The chondrodystrophies (CDX) are a heterogeneous group of disorders of endochondral bone growth that are characterized clinically by shortening and deformities of the limbs and trunk. The delineation of the pathogenetic mechanisms responsible for the disorders would be highly desirable because not only would it lead to definitive therapy for the CDX, but it would provide valuable insights into the causes of skeletal deformities in general as well as normal bone growth. Unfortunately, the understanding of the abnormalities in the CDX has been hampered by a variety of problems primarily related to obtaining and investigating the affected tissue, the skeletal growth plate. Addressing these problems, the proposed investigator has developed an approach tailored to studying these disorders. It involves the use of highly specific histochemistry to localize matrix constituents in plastic embedded tissues combined with biochemical analysis of extremely small samples of cartilage. Preliminary studies have demonstrated its potential value as a means to probe the growth plate as a dynamic structure. It is now proposed to expand this approach to systematically and comprehensively examine endochondral ossification in growth plate tissue from normal control and CDX patients. The tissue will be studied by light and electron microscopic immune and lectin histochemistry, autoradiography, and in situ hybridization. Monoclonal antibodies to matrix components: types I-VI, IX (G), X (M), and 1Alpha, 2Alpha, 3Alpha collagens; chondroitin-4- and -6- sulfate, keratan sulfate and hyaluronic acid binding region substructures of cartilage proteoglycan; link protein; fibronectin; and cDNA probes to specific skeletal procollagen mRNAs will be employed. To biochemically confirm the microscopic observations, microsamples of the cartilages corresponding to different stages of chondrocyte proliferation and differentiation will be studied in organ culture by HPLC and SDS-PAGE methods to determine the presence of and relative proportions of isotopically labeled major and minor collagens and glycosaminoglycans in newly synthesized matrix. These studies should permit an accurate representation of the events of normal endochondral ossification to be constructed and defects therein to be identified.