Annexin 1 and its bioactive peptide inhibit neutrophil-endothelium interactions under flow: indication of distinct receptor involvement.
We have tested the effects of annexin 1 (ANXA1) and its N-terminal peptide Ac2-26 on polymorphonuclear leukocyte (PMN) recruitment under flow. Differential effects of the full-length protein and its peptide were observed; ANXA1 inhibited firm adhesion of human PMNs, while Ac2-26 significantly attenuated capture and rolling without effect on firm adhesion. Analysis of the effects of ANXA1 and Ac2-26 on PMN adhesion molecule expression supported the flow chamber results, with Ac2-26 but not ANXA1 causing l-selectin and PSGL-1 shedding. ANXA1 and its peptide act via the FPR family of receptors. This was corroborated using HEK-293 cells transfected with FPR or FPRL-1/ALX (the 2 members of this family expressed by human PMNs). While Ac2-26 bound both FPR and FPRL-1/ALX, ANXA1 bound FPRL-1/ALX only. ANXA1 and Ac2-26 acted as genuine agonists; Ac2-26 binding led to ERK activation in both FPR- and FPRL-1/ALX-transfected cells, while ANXA1 caused ERK activation only in cells transfected with FPRL-1/ALX. Finally, blockade of FPRL-1/ALX with a neutralizing monoclonal antibody was found to abrogate the effects of ANXA1 in the flow chamber but was without effect on Ac2-26-mediated inhibition of rolling. These findings demonstrate for the first time distinct mechanisms of action for ANXA1 and its N-terminal peptide Ac2-26.
Hayhoe
Richard P G
RP
Centre for Biochemical Pharmacology, The William Harvey Research Institute, London, United Kingdom.
Kamal
Ahmad M
AM
Solito
Egle
E
Flower
Roderick J
RJ
Cooper
Dianne
D
Perretti
Mauro
M
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D017305:Annexin A1 / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002460:Cell Line; D018920:Coculture Techniques; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D019041:L-Selectin / Q000378:metabolism; D036904:Leukocyte Rolling / Q000187:drug effects* / Q000235:genetics; D008562:Membrane Glycoproteins / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology*; D044042:Receptors, Formyl Peptide / Q000235:genetics / Q000378:metabolism; D044067:Receptors, Lipoxin / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D014162:Transfection
D048868:Adaptor Proteins, Signal Transducing; D017305:Annexin A1; D000911:Antibodies, Monoclonal; C105101:FPR2 protein, human; C442142:HSH2D protein, human; D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; D010455:Peptides; D044042:Receptors, Formyl Peptide; D044067:Receptors, Lipoxin; C096153:annexin A1 peptide (2-26); D019041:L-Selectin; D048049:Extracellular Signal-Regulated MAP Kinases