Analysis of the role of the PAC1 receptor in neutrophil recruitment, acute-phase response, and nitric oxide production in septic shock.
Infections caused by Gram-negative bacteria constitute one of the major causes of septic shock, which results from the inability of the immune system to limit bacterial spread during the ongoing infection. In the last decade, it has been demonstrated that vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are two endogenous immunopeptides, which together with three G protein-coupled receptors (VPAC1, VPAC2, and PAC1) exert a significant, therapeutic effect attenuating the deleterious consequences of septic shock by balancing pro- and anti-inflammatory factors. We have recently shown PAC1 receptor involvement in vivo as an anti-inflammatory receptor, at least in part, by attenuating lipopolysaccharide-induced production of proinflammatory interleukin-6. The present study deepens in the protective role of PAC1 receptor in septic shock, elucidating its involvement in the modulation of neutrophil recruitment and in the expression of different molecular sensors such as intercellular adhesion molecule-1, vascular cell adhesion molecule-1, fibrinogen, serum amyloid A, and nitric oxide as important, systemic players of the development of septic shock. Our results, using a mice deficient in PAC1 and a PAC1 antagonist, show that VIP and PACAP as well as the PAC1 receptor are involved in neutrophil recruitment in different target organs, in adhesion molecules expression, and in coagulation-related molecule fibrinogen synthesis. Thus, this study provides some important insights with respect to the involvement of PAC1 into the complexities of sepsis and represents an advantage for the design of more specific drugs complementing standard intensive care therapy in severe sepsis, confirming VIP and PACAP as candidates for multitarget therapy of septic shock.
Martínez
Carmen
C
Department of Cell Biology, Faculty of Medicine, Complutense University, Madrid, Spain. cmmora@bio.ucm.es
Juarranz
Yasmina
Y
Abad
Catalina
C
Arranz
Alicia
A
Miguel
Begoña G
BG
Rosignoli
Florencia
F
Leceta
Javier
J
Gomariz
Rosa P
RP
D000210:Acute-Phase Reaction / Q000276:immunology*; D000818:Animals; D005340:Fibrinogen / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology; D007422:Intestines / Q000276:immunology; D008070:Lipopolysaccharides / Q000633:toxicity; D008099:Liver / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009414:Nerve Growth Factors / Q000276:immunology; D009479:Neuropeptides / Q000276:immunology; D018377:Neurotransmitter Agents / Q000276:immunology; D020556:Neutrophil Infiltration / Q000187:drug effects / Q000276:immunology*; D009569:Nitric Oxide / Q000276:immunology*; D009195:Peroxidase / Q000276:immunology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology*; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D000685:Serum Amyloid A Protein / Q000276:immunology; D012772:Shock, Septic / Q000276:immunology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000276:immunology; D014660:Vasoactive Intestinal Peptide / Q000276:immunology
C495402:Adcyap1 protein, mouse; C495504:Adcyap1r1 protein, mouse; D008070:Lipopolysaccharides; D009414:Nerve Growth Factors; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011956:Receptors, Cell Surface; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D051239:Receptors, Vasoactive Intestinal Peptide, Type II; D051238:Receptors, Vasoactive Intestinal Polypeptide, Type I; D000685:Serum Amyloid A Protein; D019010:Vascular Cell Adhesion Molecule-1; C495507:Vipr1 protein, mouse; C495510:Vipr2 protein, mouse; D018799:Intercellular Adhesion Molecule-1; D009569:Nitric Oxide; D014660:Vasoactive Intestinal Peptide; D005340:Fibrinogen; D009195:Peroxidase