Roflumilast inhibits leukocyte-endothelial cell interactions, expression of adhesion molecules and microvascular permeability.
OBJECTIVE
The present study addressed the effects of the investigational PDE4 inhibitor roflumilast on leukocyte-endothelial cell interactions and endothelial permeability in vivo and in vitro.


METHODS
In vivo, intravital video-microscopy was used to determine effects of roflumilast p.o. on leukocyte-endothelial cell interactions and microvascular permeability in rat mesenteric venules. In vitro, the effects of roflumilast N-oxide, the active metabolite of roflumilast in humans, and other PDE4 inhibitors on neutrophil adhesion to tumour necrosis factor alpha (TNFalpha)-activated human umbilical vein endothelial cells (HUVEC), E-selectin expression and thrombin-induced endothelial permeability was evaluated. Flow cytometry was used to determine the effect of roflumilast on N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced CD11b upregulation on human neutrophils.


RESULTS
In vivo, roflumilast, given 1 h before lipopolysaccharide (LPS), dose-dependently reduced leukocyte-endothelial cell interactions in rat mesenteric postcapillary venules. It also diminished histamine-induced microvascular permeability. Immunohistochemical analyses revealed that roflumilast prevented LPS-induced endothelial P- and E-selectin expression. In vitro, roflumilast N-oxide concentration-dependently suppressed neutrophil adhesion to TNFalpha-activated HUVEC and CD11b expression on fMLP-stimulated neutrophils. It also reduced TNFalpha-induced E-selectin expression on HUVEC, when PDE3 activity was blocked. HUVEC permeability elicited by thrombin was concentration-dependently suppressed by roflumilast N-oxide. While roflumilast N-oxide was as potent as roflumilast at inhibiting stimulated endothelial cell and neutrophil functions, both compounds were significantly more potent than the structurally unrelated PDE4 inhibitors, rolipram or cilomilast.


CONCLUSIONS
These findings further support earlier observations on the inhibition of inflammatory cell influx and protein extravasation by roflumilast in vivo.
Sanz
M-J
MJ
Department of Pharmacology, University of Valencia, Valencia, Spain.
Cortijo
J
J
Taha
M A
MA
Cerdá-Nicolás
M
M
Schatton
E
E
Burgbacher
B
B
Klar
J
J
Tenor
H
H
Schudt
C
C
Issekutz
A C
AC
Hatzelmann
A
A
Morcillo
E J
EJ
D000631:Aminopyridines / Q000494:pharmacology*; D000818:Animals; D001549:Benzamides / Q000494:pharmacology*; D039481:CD11b Antigen / Q000378:metabolism; D002199:Capillary Permeability / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002450:Cell Communication / Q000187:drug effects*; D002460:Cell Line; D002478:Cells, Cultured; D003521:Cyclopropanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects*; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D008642:Mesenteric Veins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019087:Selectins / Q000235:genetics / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D000631:Aminopyridines; D001549:Benzamides; D039481:CD11b Antigen; D015815:Cell Adhesion Molecules; D003521:Cyclopropanes; D008070:Lipopolysaccharides; D010726:Phosphodiesterase Inhibitors; D012333:RNA, Messenger; D019087:Selectins; D014409:Tumor Necrosis Factor-alpha; C424423:Roflumilast; C517734:roflumilast N-oxide
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