Functional peptide of dermatopontin produces fibrinogen fibrils and modifies its biological activity

Background: Dermatopontin (DP), a small extracellular matrix protein, interacts with both fibrinogen and fibrin. DP accelerates fibrin fibril formation and enhances cell adhesion to fibrin fibrils but DP does not influence fibrinogen fibril formation. We have previously demonstrated that DP-4 (PHGQVVVAVRS) is a functional dermatopontin peptide (Wu et al., 2014). Objective: Identification of biological functions of DP-4. Methods: Protein-protein interactions were examined by solid-phase assay. The kinetics of fibrinogen/fibrin polymer formation was monitored by turbidity change, SDS-PAGE, and electron microscopy. A cell adhesion assay was performed using human umbilical vein endothelial cells. Results: Although DP promoted fibrin formation, the DP-4 peptide promoted fibrinogen polymerization but did not apparently affect fibrin formation. The polymerized fibrinogen formed straight solid fibrils comparable to the normally formed fibrin fibrils. A minimum functional sequence of the DP-4 peptide was determined to be VVVAVRS. An cif domain in fibrinogen was involved in the fibril formation. Fibrinogen fibrils made by DP-4 enhanced endothelial cell adhesion and spreading in a dose-dependent manner. This cell adhesion was inhibited by heparin and by anti-alpha v beta 3 and beta 1 integrin antibodies. Conclusion: DP-4 did not reproduce the full functional biological activities of DP with fibrin but DP-4 did promote fibrinogen fibril formation. The fibrinogen fibrils produced by DP-4 are useful as a novel synthetic biomaterial for therapeutic applications. (C) 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.