Progenitor Cells From Cartilage

Abstract

BACKGROUND: Recent research confirmed the presence of Mesenchymal stem cell (MSC) - like progenitors (MPC) in both normal and osteoarthritic cartilage. However, there is only limited information concerning how MPC markers develop with osteoarthritis progression. The purpose of this study is to determine the prevalence of MPC markers in different OA grades. MATERIALS AND METHODS: Human osteoarthritic tibial plateau were obtained from ten patients undergoing total knee replacement. Each sample had been classified into a mild or severe group according to OARSI scoring. Tissue was taken from each specimen and mRNA expression levels of CD105, CD166, Notch 1, Sox9, Acan and Col II A1 were measured at day 0 and day 14 (2 weeks in vitro). Furthermore, MSC markers: Nucleostemin, CD90, CD73, CD166, CD105 and Notch 1 were studied by immunofluorescence. RESULTS: mRNA levels of MSC markers did not differ between mild and severe OA at day 0. At day 14, protein analysis showed that proliferated cells from both sources express all 6 MSC markers. Only cells from mild OA resulted in a significant increase of mRNA CD105 and CD166 after in vitro expansion. Moreover, cells from the mild OA showed significantly higher levels of CD105, Sox9 and Acan than those from severe OA. CONCLUSION: Results confirmed the presence of MSC markers in mild and severe OA tissue on both mRNA and protein levels. We found potential differences between cells obtained from mild compared to severe which suggests that mild OA derived cells may have a greater MSC potential.