Development of new antiatherosclerotic and antithrombotic drugs utilizing F11 receptor (F11R/JAM‐A) peptides

Abstract

Peptides with enhanced resistance to proteolysis, based on the amino acid sequence of the F11 receptor molecule (F11R, aka JAM-A/Junctional adhesion molecule-A), were designed, prepared, and examined as potential candidates for the development of anti-atherosclerotic and anti-thrombotic therapeutic drugs. A sequence at the N-terminal of F11R together with another sequence located in the first Ig-loop of this protein, were identified to form a steric active-site operating in the F11R-dependent adhesion between cells that express F11R molecules on their external surface. In silico modeling of the complex between two polypeptide chains with the sequences positioned in the active-site was used to generate peptide-candidates designed to inhibit homophilic interactions between surface-located F11R molecules. The two lead F11R peptides were modified with D-Arg and D-Lys at selective sites, for attaining higher stability to proteolysis in vivo. Using molecular docking experiments we tested different conformational states and the putative binding affinity between two selected D-Arg and D-Lys-modified F11R peptides and the proposed binding pocket. The inhibitory effects of the F11R peptide 2HN-(dK)-SVT-(dR)-EDTGTYTC-CONH2 on antibody-induced platelet aggregation and on the adhesion of platelets to cytokine-inflammed endothelial cells are reported in detail, and the results point out the significant potential utilization of F11R peptides for the prevention and treatment of atherosclerotic plaques and associated thrombotic events.

Functional inhibition of F11 receptor (F11R/junctional adhesion molecule-A/JAM-A) activity by a F11R-derived peptide in breast cancer and its microenvironment

“…F11R/JAM-A derived peptides were previously applied for the drug development in the cardiovascular disorders [7,10,31,32,44]. Here, we report that Tβ4 and TGF-β1 decrease the plasma levels of sJAM-A in the murine 4T1 model.…”

“…Moreover, inflammatory cytokines increase the leukocyte adhesion to endothelium, thus triggering F11R-dependent TEM [40]. Consequently, we employed the F11R/JAM-A antagonistic peptide 4D [31,32] that blocked the breast cancer cell adhesion to the inflamed endothelium, which was particularly evident for MDA-MB-231 cells (Fig. 4a).…”

“…For the inhibition of TJ formation between the cancer cells and endothelium, the cells were treated with the P4D peptide with the sequence of a 70-82 amino acids fragment of the F11R/JAM-A mature polypeptide chain that is responsible for F11R/JAM-A transhomodimerization [31]. The peptide P4D is a d-amino acid analog of the native peptide that binds to the 70-82 amino acid fragments and blocks the trans-homodimerization of F11R/JAM-A molecules, thus inhibiting the TJs formation in the endothelial monolayer as well as between the cancer cells and endothelial cells [32]. The sequence of control peptide (Scr) corresponded to P4D peptide, but was scrambled by random insertion of amino acid residues during the synthesis process.…”

Targeting Opposing Immunological Roles of the Junctional Adhesion Molecule-A in Autoimmunity and Cancer

“…In vitro, treatment with a JAM-A antagonistic peptide capable of blocking homophilic binding (peptide 4D), decreased platelet adhesion to inflamed endothelial cells, whereas agonistic reagents promoted platelet aggregation (12,37). This antagonistic peptide also decreased plaque number and size and increased survival of mice in an atherosclerosis model in comparison with mice treated with a scrambled peptide (38), due to a reduction on platelet adhesion to the inflamed endothelium.…”

In Vitro Methods for Measuring the Permeability of Cell Monolayers

“…Accordingly, we have developed the F11R/JAM-A peptide antagonist P4D that disturbs the homophilic interactions between F11R/JAM-A molecules located on the surfaces of two different, adjacent cells and thus inhibits the tight junctions formation [26]. P4D sequence is based on the 70-82 amino acids fragment of the F11R/JAM-A polypeptide chain, that is located in the first immunoglobulin-fold (Ig-Fold) of the protein's molecule.…”