Octa-arginine and Octa-lysine Promote Cell Adhesion through Heparan Sulfate Proteoglycans and Integrins

Octa-arginine (R8) has been extensively studied as a cell-penetrating peptide. R8 binds to diverse transmembrane heparan sulfate proteoglycans (HSPGs), including syndecans, and is internalized by cells. R8 is also reported to bind to integrin beta 1. In this study, we evaluated the biological activities of R8 and octa-lysine (K8), a peptide similar to R8, with a focus on cell adhesion. R8 and K8 were immobilized on aldehydeagarose matrices via covalent conjugation, and the effect of these peptides on cell attachment, spreading, and proliferation was examined using human dermal fibroblasts. The results indicated that R8- and K8-matrices mediate cell adhesion mainly via HSPGs. Moreover, R8- and K8-matrices interacted with integrin beta 1 and promote cell spreading and proliferation. These results are useful for further understanding of the RS-membrane interactions and the cellular uptake mechanisms. In addition, the R8- and KS-matrices may potentially be used as a multi-functional biomaterial to promote cell adhesion, spreading, and proliferation.