Genetics of Cartilage Regeneration and Osteoarthritis

描述(申请人提供)：这项建议是由Linda Sandell博士和James Cheverud博士提出的，前者是矫形外科和细胞生物系的软骨生物学家，后者是解剖学和神经生物学系的群体遗传学家和形态学家。利用与“超级愈合”小鼠相关的品系(包括重组近交系和高级杂交品系)，我们定义了关节软骨再生和耳朵组织再生的表型，并建立了这两种表型之间的强烈正相关。此外，概念验证研究表明，修复关节软骨的能力可能与预防创伤后骨关节炎有关。这一独特的遗传资源将被用来测试耳部伤口愈合、软骨再生和骨关节炎之间的联系，并系统地识别有助于软骨再生从而促进骨关节炎发展的基因。目前赠款提案的具体目标是：(1)在重组近交系LG/J和SM/J中测试关节软骨再生和骨关节炎之间的相关性，映射到大约10厘米；(2)确定关节软骨再生和骨关节炎在LG/J和SM/J高级杂交中的分布，将这些区域映射到包含1-5个基因的亚厘米间隔；(3)确定在代表极端愈合的品系中软骨和干细胞反应中建立的应变差异的细胞和分子机制，以及(4)使用系统教育的候选基因方法，通过我们的“借耳朵治疗骨性关节炎”活动验证基因。用于实现这些特定目的的方法依赖于具有不同再生软骨和耳组织能力的重组近交系和高级杂交菌株LG/J和SM/J的可用性，并结合小鼠手术技术对关节软骨损伤和内侧半月板失稳(DMM骨关节炎模型)进行组织学和显微CT分析。软骨和干细胞的功能分析将在极端愈合的菌株中进行。基因参与的证据将通过使用基因敲除小鼠的DMM骨关节炎模型来建立。该项目的结果将是识别影响小鼠骨关节炎发展和关节软骨再生的基因，为探测人类基因组提供高质量的候选基因。

DESCRIPTION (provided by applicant): This proposal is from Dr. Linda Sandell, a cartilage biologist in the Departments of Orthopaedic Surgery and Cell Biology and Dr. James Cheverud, a population geneticist and morphologist in the Department of Anatomy and Neurobiology. Using strains related to the "super healing" mouse (both recombinant inbred strains and an advanced intercross), we have defined phenotypes of articular cartilage regeneration and ear tissue regeneration and established a strong positive correlation between these two phenotypes. Furthermore, proof- of-concept studies demonstrate that the ability to heal articular cartilage may be associated with protection from post-traumatic osteoarthritis. This unique genetic resource will be used to test the association between ear wound healing, cartilage regeneration and osteoarthritis and to systematically identify genes that contribute to cartilage regeneration and thus to osteoarthritis development. The specific aims of the current grant proposal are: (1) Test the correlation between articular cartilage regeneration and osteoarthritis in recombinant inbred lines of LG/J and SM/J, mapping to approximately 10 cM (2) Determine the distribution of articular cartilage regeneration and osteoarthritis in the advanced intercross f LG/J and SM/J, mapping these regions to sub-cM intervals containing 1-5 genes (3) Determine the cell and molecular mechanisms responsible for established strain differences in cartilage and stem cell responses in the strains that represent extremes of healing, and (4) Using a systems-educated candidate gene approach, validate genes through our "Lend an Ear for Osteoarthritis" Campaign. The methods used to undertake these specific aims rely on the availability of recombinant inbred and advanced intercross strains of LG/J and SM/J with different abilities to regenerate cartilage and ear tissue combined with mouse surgical techniques for articular cartilage wounding and destabilization of the medial meniscus (DMM osteoarthritis model), analyzed by histology and micro-CT. Functional analyses of cartilage and stem cells will be performed in the strains that are extremes of healing. Proof of gene involvement will be established by using the DMM osteoarthritis model in knock-out mice. The outcome of this project will be the identification of genes affecting osteoarthritis development and articular cartilage regeneration in mice, providing high-quality candidates for probing the human genome.