title: Haemorrhagic shock in mice--intracellular signalling and immunomodulation of peritoneal macrophages' LPS response.
abstract: Haemorrhagic shock leads to decreased proinflammatory cytokine response which is associated with an increased susceptibility to bacterial infections. In the present study, the effect of GM-CSF on lipopolysaccharide (LPS)-induced TNF-alpha release and MAPkinase activation was analysed on the background of a possible immunostimulating activity of this substance. Male BALB/c mice were bled to a mean arterial blood pressure of 50 mmHg for 45 min followed by resuscitation. Peritoneal macrophages were isolated 20 h after haemorrhage and incubated with 10 ng/ml GM-CSF for 6h before LPS stimulation. TNF-alpha synthesis was studied in the culture supernatants using ELISA. Phosphorylation of ERK, p38MAPK and IkappaBalpha was detected by Western blotting. LPS-induced TNF-alpha production of peritoneal macrophages was significantly decreased 20 h after haemorrhage in comparison to the corresponding cells of sham-operated mice. In parallel the phosphorylation of IkappaBalpha was less in LPS-stimulated peritoneal macrophages from haemorrhagic mice. LPS-induced phosphorylation of ERK1/2 was also decreased in peritoneal macrophages isolated after haemorrhagic shock. In contrast, p38MAPK was phosphorylated more intensely after LPS-stimulation in macrophages collected from shocked mice. GM-CSF incubation elevated LPS-induced TNF-alpha response of macrophages from both sham-operated and shocked mice which was accompanied by an elevated IkappaB and ERK phosphorylation. In general, GM-CSF treatment in vitro enhanced peritoneal macrophages LPS-response both in terms of TNF-alpha synthesis and IkappaB and MAPK signalling, but the levels always stayed lower than those of GM-CSF-treated cells from sham-operated animals. In conclusion, GM-CSF preincubation could partly reactivate the depressed functions of peritoneal macrophages and may therefore exert immunostimulating properties after shock or trauma.
authors.affiliation: Section Surgical Research Trauma Surgery, University Hospital Essen, Hufelandstr 55, 45122 Essen, Germany.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Rani
authors.forename: Baher
authors.initials: B
authors.lastname: Husain
authors.forename: Sven
authors.initials: S
authors.lastname: Lendemans
authors.forename: Fritz U
authors.initials: FU
authors.lastname: Schade
authors.forename: Sascha
authors.initials: S
authors.lastname: Flohé
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004789:Enzyme Activation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D020672:I-kappa B Proteins / Q000096:biosynthesis / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020929:Mitogen-Activated Protein Kinase Kinases / Q000096:biosynthesis / Q000187:drug effects; D000072000:NF-KappaB Inhibitor alpha; D010766:Phosphorylation; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000276:immunology*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000187:drug effects
chemical_list: D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; C000606205:Nfkbia protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D020929:Mitogen-Activated Protein Kinase Kinases