title: Phosphodiesterase type 4 blockade prevents platelet-mediated neutrophil recruitment at the site of vascular injury.
abstract: OBJECTIVE
  Platelet-neutrophil interactions play a key role in cardiovascular disease and inflammatory processes. Src family kinases mediate P-selectin glycoprotein ligand-1-Mac-1 cross talk necessary for firm platelet-neutrophil adhesion. Because Src family kinase activity can be regulated by cAMP-dependent pathways, in this work, we evaluated the role of phosphodiesterases in the signaling events that are required to sustain platelet-neutrophil interactions and neutrophil recruitment at the site of vascular injury.
  
  
  RESULTS
  In neutrophils exposed to P-selectin, selective phosphodiesterase 4 (PDE4) inhibition prevented Src family kinase-mediated phosphorylation of the proline-rich tyrosine kinase 2 on Tyr579/Tyr580. The effects of PDE4 inhibition required protein kinase A, likely through protein kinase A-mediated activation of COOH-terminal Src kinase, a major negative regulator of Src family kinases. PDE4, but not other phosphodiesterase inhibitors, reduced platelet-neutrophil conjugates as well as neutrophil firm adhesion on spread platelets under flow conditions. The effect of PDE4 inhibition on neutrophil adhesion was primarily mediated by downregulation of P-selectin-induced activation of Mac-1. In a murine model of endovascular injury, selective inhibition of PDE4 significantly reduced neutrophil recruitment at the site of vascular damage.
  
  
  CONCLUSIONS
  This study identifies PDE4 as a central node in the signaling network that mediates platelet-neutrophil adhesion and suggests that pharmacological inhibition of PDE4 may represent a novel therapeutic avenue for the treatment of cardiovascular disease.
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Licia
authors.initials: L
authors.lastname: Totani
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Antonio
authors.initials: A
authors.lastname: Piccoli
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Dell'Elba
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Amore
authors.initials: A
authors.lastname: Concetta
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Angelomaria
authors.initials: A
authors.lastname: Di Santo
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Nicola
authors.initials: N
authors.lastname: Martelli
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Federico
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Zehra
authors.initials: Z
authors.lastname: Pamuklar
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.).
authors.forename: Susan S
authors.initials: SS
authors.lastname: Smyth
authors.affiliation: From the Department of Translational Pharmacology, Laboratory of Vascular Biology and Pharmacology, Fondazione Mario Negri Sud, Santa Maria Imbaro, Chieti, Italy (L.T., A.P., G.D., A.C., A.D.S., N.M., V.E.); Division of Cardiovascular Medicine, The Gill Heart Institute, Lexington, KY (L.F., Z.P., S.S.S.); and VA Medical Center, Lexington, KY (S.S.S.). evangelista@negrisud.it.
authors.forename: Virgilio
authors.initials: V
authors.lastname: Evangelista
mesh_terms: D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000201:enzymology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004195:Disease Models, Animal; D005263:Femoral Artery / Q000187:drug effects* / Q000201:enzymology / Q000293:injuries; D051418:Focal Adhesion Kinase 2 / Q000378:metabolism; D006801:Humans; D016177:Macrophage-1 Antigen / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D020556:Neutrophil Infiltration / Q000187:drug effects*; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism*; D058988:Phosphodiesterase 4 Inhibitors / Q000494:pharmacology*; D010766:Phosphorylation; D010973:Platelet Adhesiveness / Q000187:drug effects*; D020889:Rolipram / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D057772:Vascular System Injuries / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D016177:Macrophage-1 Antigen; D019007:P-Selectin; D058988:Phosphodiesterase 4 Inhibitors; C546937:SELP protein, human; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; D051418:Focal Adhesion Kinase 2; C103547:PTK2B protein, human; D019061:src-Family Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D020889:Rolipram
keywords: neutrophils; phosphodiesterase 4 inhibitors; platelets