Hypertonic saline activation of p38 MAPK primes the PMN respiratory burst.
Investigation of hypertonic saline (HTS) modulation of neutrophils (PMN) cytotoxic responses has generated seemingly contradictory results. Clinically relevant levels of HTS attenuate receptor-mediated p38 MAPK signaling, whereas higher levels activate p38 MAPK. Concurrently, HTS exerts a dose-dependent attenuation of the PMN respiratory burst, most notably at concentrations where p38 MAPK is activated. We hypothesized that HTS-mediated p38 MAPK activation augments the PMN respiratory burst on return to normotonicity. We found that although clinically relevant levels of HTS (Na+ > or = 200 mM) did not activate p38 MAPK, higher concentrations (Na+ > or = 300 mM) resulted in activation comparable with that after PAF stimulation. Transient stimulation with high levels of HTS primed the PMN respiratory burst in response to fMLP and PMA. This effect was attenuated by pretreatment with SB 203580, a p38 MAPK specific inhibitor. We conclude that severe osmotic shock primes the respiratory burst via p38 MAPK signaling, further supporting the role of this signaling cascade in PMN priming.
Ciesla
D J
DJ
Department of Surgery, Denver Health Medical Center, Colorado 80204, USA.
Moore
E E
EE
Biffl
W L
WL
Gonzalez
R J
RJ
Moore
H B
HB
Silliman
C C
CC
D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D016897:Respiratory Burst / Q000187:drug effects*; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases
D004791:Enzyme Inhibitors; D007093:Imidazoles; D011725:Pyridines; D012462:Saline Solution, Hypertonic; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; C042932:formylmethionyl-leucyl-phenylalanine methyl ester; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D013755:Tetradecanoylphorbol Acetate; C093642:SB 203580; D010100:Oxygen