Gene expression profile of hypertrophic chondrocytes treated with H2O2:A Preliminary investigation

To identify the osteogenesis genes whose expression is altered in hypertrophic chondrocytes treated with H2O2.Methods Murine chondrogenitor cells(ATDC5)were differentiated into hypertrophic chondrocytes by Insulin-Transferrin-Selenium(ITS)treatment,and then treated with H2O2.Suitable conditions(concentration,time)were determined by using the MTT assay.After total RNA isolation and cDNA synthesis,the levels of 84 genes were determined using the PCR array,whereas quantitative RT-PCR was carried out to validate the PCR array data.Results We identified 9 up-regulated genes and 12 down-regulated genes,encoding proteins with various functions,such as collagen proteins,transcription factors,proteins involved in skeletal development and bone mineral metabolism,as well as cell adhesion molecules.Quantitative RT-PCR confirmed the altered expression of 5 down-regulated genes(Smad2,Smad4,transforming growth factorβreceptor 1,transforming growth factorβreceptor 3,and matrix metalloproteinase 10).Conclusions H2O2 significantly changed the expression of several genes involved in a variety of biological functions.Because of the link between oxidative damage and Kashin-Beck disease,these genes may also be involved in the deep-zone necrosis of the cartilage observed in Kashin-Beck disease.