Early Gene Expression of Immune Proteins in Chondrocytes Differentiation from Rat Bone Marrow Stromal Cells

To study an effective differentiation condition of chondrocytes(Ch) from rat bone marrow stromal cells(MSC) in vitro by immunohistochemistry, in situ hybridization and RT- PCR, and identify gene expression pattern of immune proteins in this process via cDNA microarray analysis. The results suggested that Dexamethasone (Dex) had an ability to promote cell proliferation. The group of TGF-beta could highly express collagen II while its cell proliferation was weaker than that of Dex group. These indicated that TGF-beta had the ability to differentiate MSC into Ch.The group of combination of TGF-beta and Dex could both express collagen II and maintain proliferation. Analysis by cDNA microarray revealed that 7 genes of immune proteins out of the 2242 rat genes had differential expression during this process, including membrane-spanning 4-domainssubfamily A; T-cell receptor active alpha-chain C-region, TRA29; MHC class I-related protein; pepti dylprolyl isomerase C-associated protein; C8b; complement component 4 binding protein a and beta.This study showed that combination cultural condition in which MSC were induced into Ch lineage was effective to repair of articular cartilage. Various immune genes were involved in Ch differentiation. This would provide foundation for repair of articular cartilage defect with Ch.