GROWTH PLATE STUDIES IN THE CHONDRODYSTROPHIES

软骨营养不良（CDX）是一组异质性的疾病， 临床上以缩短为特征的软骨内骨生长 四肢和躯干畸形。 的划定 导致这些疾病的发病机制将是高度 这是可取的，因为它不仅会导致CDX的确定性治疗， 但它会提供有价值的见解骨骼的原因， 畸形以及正常的骨骼生长。 可惜 对CDX异常的理解一直受到 各种各样的问题，主要涉及获得和调查 受影响的组织骨骼生长板 为了解决这些问题， 拟议的研究人员已经开发出一种专门研究 这些紊乱。 它涉及使用高度特异性的组织化学， 在塑料包埋组织中定位基质成分， 对极小的软骨样本进行生化分析。 初步 研究已经证明了它作为探测 生长板作为动态结构。 现在建议扩大这一点， 一种系统全面地检查软骨内分泌的方法 正常对照和CDX患者生长板组织中的骨化。 组织将通过光镜和电镜免疫和 凝集素组织化学、放射自显影和原位杂交。 基质组分单克隆抗体：I-VI、IX（G）、X（M）和 1 α，2 α，3 α胶原;软骨素-4-和-6-硫酸，角质素 软骨硫酸盐和透明质酸结合区亚结构 蛋白聚糖;连接蛋白;纤连蛋白;和特异性 将使用骨骼原胶原mRNA。 从生化角度确认 显微镜观察，软骨的微量样品对应于 软骨细胞增殖和分化的不同阶段将是 通过HPLC和SDS-PAGE方法在器官培养中进行研究，以确定 同位素标记的主要成分的存在和相对比例， 新合成基质中的次要胶原蛋白和糖胺聚糖。 这些 研究应允许正常的事件的准确代表性， 软骨内骨化，其中的缺陷， 鉴定

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.