Cells Progenitors Potential In Cartilage: Changes From Moderate To Severe Oa

Abstract

Cells progenitors potential in Cartilage: Changes from moderate to severe OA PURPOSE: Recent data suggests that osteoarthritic (OA) cartilage contains mesenchymal progenitor cells (MPC) with multi – differentiation potential. Yet, there is limited information concerning how their prevalence changes with disease stages. Herein, we explore presence, prevalence and differentiation potential of MPC cells isolated from different OA grades. METHODS: Human osteoarthritic tibial plateaus were obtained from 25 patients undergoing total knee replacement. Each sample was classified as mild, moderate or severe OA according to OARSI scoring. The mRNA expression levels of CD105, CD166, Notch 1, Sox9, Acan, Col II A1 and Col I A1 were measured at day 0, day 14 (2 weeks in vitro) and day 35 (after chondrogenesis). At D35, the pellets matrix composition was tested on formation of proteoglycan, collagen II and I by HES and Immunofluorescence. RESULTS: Cells from all OA grades significantly increased MPC markers mRNA with in vitro expression. Proliferated cells expressed MPC specific antigens: CD105, CD166, CD73, CD90, Notch – 1 and Nucleostemin. The chondrogenesis induced decrease in CD105, Notch 1 and Sox9 mRNA only in mild and moderate OA. Yet, only moderate OA – derived pellets revealed significantly high levels of proteoglycans and hyaline cartilage marker – collagen II and low expression of fibrocartilage marker – Collagen I at both mRNA and protein level. CONCLUSION: A novel finding emerges from our data confirms differences in MPC potential between OA grades. Only moderate OA – derived cells were able to form hyaline – like matrix.