Identification and initial characterization of 5000 expressed sequenced tags (ESTs) each from adult human normal and osteoarthritic cartilage cDNA libraries

Objective: To prepare, sequence and analyse adult human cartilage cDNA libr aries to study the gene expression pattern between normal and osteoarthriti c cartilage. Methods: Poly A(+) RNA from adult human normal and osteoarthritic articular cartilage was isolated and used to prepare cDNA libraries. Approximately 5 000 ESTs from each library were sequenced and analysed using bioinformatic tools. The expression of select genes was confirmed by Northern blot and in situ hybridization analysis. Results: Multiple gene families including several classical cartilage matri x protein encoding genes were identified. Approximately 28-40% of the genes sequenced from these libraries were novel, while half of the genes encoded known proteins and 4-6% of the genes encoded novel homologs of known prote ins. Several known genes, whose expression has not been reported previously in cartilage, were also identified. We have confirmed the cartilage expres sion of three known (CTGF, CTGF-L and clusterin) and two novel homologs of known genes (PCPE-2 and Gal-Nac transferase) by Northern blot and in situ h ybridization analysis. Conclusion: This is the first report of the preparation and sequencing of c DNA libraries from adult human normal and osteoarthritic articular cartilag e. Further analysis of genes identified from these libraries may provide mo lecular targets for diagnosis and/or treatment of osteoarthritis (OA). (C) 2001 OsteoArthritis Research Society International.