Phagocyte-derived catecholamines enhance acute inflammatory injury.
It is becoming increasingly clear that the autonomic nervous system and the immune system demonstrate cross-talk during inflammation by means of sympathetic and parasympathetic pathways. We investigated whether phagocytes are capable of de novo production of catecholamines, suggesting an autocrine/paracrine self-regulatory mechanism by catecholamines during inflammation, as has been described for lymphocytes. Here we show that exposure of phagocytes to lipopolysaccharide led to a release of catecholamines and an induction of catecholamine-generating and degrading enzymes, indicating the presence of the complete intracellular machinery for the generation, release and inactivation of catecholamines. To assess the importance of these findings in vivo, we chose two models of acute lung injury. Blockade of alpha2-adrenoreceptors or catecholamine-generating enzymes greatly suppressed lung inflammation, whereas the opposite was the case either for an alpha2-adrenoreceptor agonist or for inhibition of catecholamine-degrading enzymes. We were able to exclude T cells or sympathetic nerve endings as sources of the injury-modulating catecholamines. Our studies identify phagocytes as a new source of catecholamines, which enhance the inflammatory response.
Flierl
Michael A
MA
Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
Rittirsch
Daniel
D
Nadeau
Brian A
BA
Chen
Anthony J
AJ
Sarma
J Vidya
JV
Zetoune
Firas S
FS
McGuire
Stephanie R
SR
List
Rachel P
RP
Day
Danielle E
DE
Hoesel
L Marco
LM
Gao
Hongwei
H
Van Rooijen
Nico
N
Huber-Lang
Markus S
MS
Neubig
Richard R
RR
Ward
Peter A
PA
D000208:Acute Disease; D058669:Adrenergic alpha-2 Receptor Antagonists; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008171:Lung Diseases / Q000378:metabolism* / Q000473:pathology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D010586:Phagocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism
D058669:Adrenergic alpha-2 Receptor Antagonists; D002395:Catecholamines; D008070:Lipopolysaccharides; D018341:Receptors, Adrenergic, alpha-2