Cyclization of the urokinase receptor-derived ser-arg-ser-arg-tyr Peptide generates a potent inhibitor of trans-endothelial migration of monocytes.
The receptor for the urokinase-type plasminogen activator (uPAR) is a widely recognized master regulator of cell migration and uPAR88-92 is the minimal sequence required to induce cell motility. We and others have previously documented that the uPAR88-92 sequence, even in the form of synthetic linear peptide (SRSRY), interacts with the formyl peptide receptor type 1 (FPR1), henceforth inducing cell migration of several cell lines, including monocytes. FPR1 is mainly expressed by mammalian phagocytic leukocytes and plays a crucial role in chemotaxis. In this study, we present evidence that the cyclization of the SRSRY sequence generates a new potent and stable inhibitor of monocyte trafficking. In rat basophilic leukaemia RBL-2H3/ETFR cells expressing high levels of constitutively activated FPR1, the cyclic SRSRY peptide ([SRSRY]) blocks FPR1 mediated cell migration by interfering with both internalization and ligand-uptake of FPR1. Similarly to RBL-2H3/ETFR cells, [SRSRY] competes with fMLF for binding to FPR1 and prevents agonist-induced FPR1 internalization in human monocyte THP-1 cells. Unlike scramble [RSSYR], [SRSRY] inhibits fMLF-directed migration of monocytes in a dose-dependent manner, with IC50 value of 0.01 nM. PMA-differentiated THP-1 cell exposure to fMLF gradient causes a marked cytoskeletal re-organization with the formation of F-actin rich pseudopodia that are prevented by the addition of [SRSRY]. Furthermore, [SRSRY] prevents migration of human primary monocytes and trans-endothelial migration of monocytes. Our findings indicate that [SRSRY] is a new FPR1 inhibitor which may suggest the development of new drugs for treating pathological conditions sustained by increased motility of monocytes, such as chronic inflammatory diseases.
Department of Pharmacy, University Federico II, Naples, Italy.
Ali Munaim
AM
Yousif
Neoplastic Progression Unit, Department of Experimental Oncology, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy.
Michele
M
Minopoli
Neoplastic Progression Unit, Department of Experimental Oncology, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy.
Katia
K
Bifulco
Neoplastic Progression Unit, Department of Experimental Oncology, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy; SUN Second University of Naples, Italy.
Vincenzo
V
Ingangi
Neoplastic Progression Unit, Department of Experimental Oncology, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy.
Gioconda
G
Di Carluccio
Department of Pharmacy, University Federico II, Naples, Italy.
Francesco
F
Merlino
University 'Parthenope', Naples, Italy.
Maria Letizia
ML
Motti
Department of Pharmacy, University Federico II, Naples, Italy; CIRPEB: Centro Interuniversitario di Ricerca sui Peptidi Bioattivi University of Naples "Federico II", DFM-Scarl, Institute of Biostructures and Bioimaging-CNR, 80134, Naples, Italy.
Paolo
P
Grieco
Neoplastic Progression Unit, Department of Experimental Oncology, IRCCS Istituto Nazionale Tumori "Fondazione G. Pascale", Naples, Italy.
Maria Vincenza
MV
Carriero
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D003500:Cyclization; D008264:Macrophages / Q000187:drug effects / Q000502:physiology; D009000:Monocytes / Q000187:drug effects* / Q000502:physiology*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D011485:Protein Binding; D051381:Rats; D055293:Receptors, Urokinase Plasminogen Activator / Q000737:chemistry* / Q000378:metabolism*; D057705:Transendothelial and Transepithelial Migration / Q000187:drug effects*
D010455:Peptides; D055293:Receptors, Urokinase Plasminogen Activator