AGGRECAN STRUCTURAL VARIANTS--MATRIX AND OSTEOARTHRITIS

描述（改编自申请人的摘要）：该提案是 旨在研究聚集蛋白聚糖的结构与其 在关节软骨基质中的功能作用。 Aggrecan是一种 其核心蛋白带有超过100个硫酸软骨素链的蛋白聚糖， 并聚集成大的聚集体， 在组织中的压力，并帮助它作为一个缓冲材料内 关节 这项申请是基于最近的观察， 人类聚集蛋白聚糖核心蛋白表现出独特的 多态性，在不同的细胞中产生不同长度的核心蛋白。 个体，并导致聚集蛋白聚糖分子，其潜在的数量 硫酸软骨素附着位点可以变化高达30%。 这种结构 差异可能会影响分子的功能， 这种情况是更有趣的观察，其中一个 多态性聚集蛋白聚糖等位基因优先与双侧 手部骨关节炎 为了研究变异体之间的关系 多态性硫酸软骨素附着区和软骨功能， 永生化软骨细胞系将被稳定转染 其中多态性区域侧翼为聚集蛋白聚糖的小基因构建体 G1和G3结构域。 不同的细胞系表现出高水平和低水平的 将分析重组表达以研究可能发生的变异， 硫酸化的大小、类型和取代的位置 硫酸软骨素链 产生的矩阵的性质 重组表达细胞系也将在琼脂糖培养中进行研究 系统 将通过以下方式评估所得矩阵的结构： 显微镜技术，并通过生物力学测试其功能。 的 结果数据将用于检验假设，即不同的 聚集蛋白聚糖等位基因可以影响软骨的功能特性， 将为今后研究它们在发展中的作用奠定基础， 骨关节炎

DESCRIPTION (Adapted from the Applicant's Abstract): This proposal is designed to study the relationship between the structure of aggrecan and its functional role in the matrix of articular cartilage. Aggrecan is a proteoglycan whose core protein bears over 100 chondroitin sulfate chains, and which assembles into large aggregates that create a strong swelling pressure in the tissue and help it to serve as a cushioning material within articulating joints. This application is based on the recent observation that the human aggrecan core protein exhibits a unique degree of polymorphism, which produces core proteins of different lengths in different individuals, and results in aggrecan molecules whose potential number of chondroitin sulfate attachment sites may vary by up to 30%. Such structural differences could potentially influence the function of the molecule, and this scenario is made more intriguing by the observation that one of the polymorphic aggrecan alleles is preferentially associated with bilateral osteoarthritis of the hand. To study the relationship between the variant polymorphic chondroitin sulfate-attachment regions and cartilage function, an immortalized chondrocyte cell line will be stably transfected with mini-gene constructs in which the polymorphic region is flanked by aggrecan G1 and G3 domains. Different cells lines exhibiting high and low levels of recombinant expression will be analyzed to study variations that may occur in the size, type of sulfation and position of substitution of the chondroitin sulfate chains. The nature of the matrix produced by the recombinant-expressing cell lines will also be studied in an agarose culture system. The structure of the resulting matrix will be assessed by microscopy techniques, and its function by biomechanical testing. The resulting data will be used to test the hypothesis that the different aggrecan alleles can affect the functional properties of the cartilage, and will establish a basis for future study of their role in the development of osteoarthritis.