Function of linear and cyclic RGD-containing peptides in osteoprogenitor cells adhesion process

Cell adhesion directly influences cell growth, differentiation and migratio n as well as morphogenesis, integrity and repair. The extracellular matrix (ECM) elaborated by osteoblast cells constitutes a regulator of the cell ad hesion process and then of the related phenomenon. These regulatory effects of ECM are mediated through integrins and some of them are able to bind RG D sequences. The aim of this study was to determine the role of the sequenc e and the structure of RGD-containing peptides (linear and cyclic) as well as their role in the cell adhesion process. Cell adhesion assays onto ECM p roteins coated surfaces were performed using a range of linear and cyclic R GD-containing peptides. We showed a different human osteoprogenitor cell ad hesion according to the coating for ECM proteins and for RGD-peptides. Inhi bition assays using peptides showed different responses depending on the co ated protein. Depending on the amino-acid sequence and the structure of the peptides (cyclic/linear), we observed 100% inhibition of cell adhesion ont o vitronectin. These results suggest the importance of sequence, structure and conformation of the peptide, which may play a crucial function in the l igand/receptor interaction and/or in the stability of the interaction. (C) 2001 Elsevier Science Ltd. All rights reserved.