Articular chondrocytes interact with basement membrane Matrigel through laminin active binding sites

Laminin-like molecules are detected during the differentiation of embryonic mesenchyme into cartilage and in cartilage during amphibian limb regeneration and fracture repair. Since primary articular chondrocytes in culture recognize and respond to laminin from basement membrane, the author studied the effect of laminin-derived peptides, which are thought to be responsible for biological activities of laminin. The biologically active peptides from both the laminin B1 and A chains containing YIGSR, RGD and IKVAV sequences all promoted chondrocyte attachment, and blocked laminin mediated cell attachment, with the IKVAV-containing peptide being the most effective. Laminin promoted cell migration with a maximum activity at 20 micrograms/ml. YIGSR at 100 micrograms/ml was the most active peptide exhibiting about 48% of the chemotactic activity of laminin, whereas the IKVAV-and RGD-containing peptides were much less active. When added in solution to the primary chondrocytes grown on Matrigel, YIGSR-containing peptides prevented cell alignment, whereas in the presence of peptides containing IKVAV sequence the cells spread rapidly and proliferated for 24 h. RGD-containing peptides had no effect on cell behavior on Matrigel.