[Interaction between human chondrocytes and extracellular matrix in vitro: a contribution to autologous chondrocyte transplantation].

BACKGROUND: Autologous chondrocyte transplantation (ACT) has had reasonable success for repairing small articular cartilage defects. A limiting factor for ACT is, however, the in vitro cultivation of chondrocytes because it leads to dedifferentiation. Therefore, the goal of this work was to optimize the monolayer culture of chondrocytes in vitro. MATERIAL AND
METHOD: Human articular chondrocytes were plated on either collagen type II or untreated surfaces. The cells were evaluated morphologically and with immunoblotting.
RESULTS: On collagen type II surfaces, a stable chondrogenic phenotype, expression of beta1-integrin, and a significant activation of phosphorylated intracellular proteins and the adaptor protein Shc could be observed up to day 20 in culture. Treatment with beta1 integrin antibody led to a loss of cell adhesion (82%). The results indicate that on collagen type II, beta1-integrin receptors are activated. Through the activation of Shc, these stimulate the Ras-MAPK pathway, which stabilizes the chondrogenic phenotype.
CONCLUSION: Our results provide a practical and low-cost solution for improved long-term chondrocyte cultivation, thus providing a new perspective for using ACT on larger or arthrotic cartilage defects.