Systemic NO production during (septic) shock depends on parenchymal and not on hematopoietic cells: in vivo iNOS expression pattern in (septic) shock.
Septic shock is the leading cause of death in noncoronary intensive care units and the 10th leading cause of death overall. Several lines of evidence support an important role for the vasodilator NO in hypotension, a hallmark of septic shock. However, NO may also positively or negatively regulate inflammation, apoptosis, and oxidative stress. These dual effects of NO may relate to its isoform specific production but also to differences in cellular and/or temporal expression. Via bone marrow transplantations, we examined the contribution of hematopoietic cells to the dramatically elevated NO levels seen in (septic) shock. Surprisingly, hematopoietic cells are not responsible at all for the production of circulating NO after systemic tumor necrosis factor or lipopolysaccharide challenge and contribute only marginally in a bacteremic (Salmonella) model of septic shock. Immunohistochemistry identified the nonhematopoietic sources of NO as hepatocytes, paneth cells, and intestinal and renal epithelial cells. In contrast, during granulomatous Bacillus Calmette-Guérin inflammation, the hematopoietic cell population represents the sole source of systemic NO. These mouse data demonstrate that, in contrast to the general conjecture, the dramatically elevated levels of NO during (septic) shock are not produced by hematopoietic cells such as monocytes/macrophages but rather by parenchymal cells in liver, kidney and gut.
Bultinck
Jennyfer
J
Department for Molecular Biomedical Research, Ghent University/VIB, Technologiepark 927, Ghent 9052, Belgium.
Sips
Patrick
P
Vakaet
Luc
L
Brouckaert
Peter
P
Cauwels
Anje
A
D000818:Animals; D017931:DNA Primers; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D007249:Inflammation / Q000503:physiopathology; D015850:Interleukin-6 / Q000097:blood; D007668:Kidney / Q000503:physiopathology; D008099:Liver / Q000503:physiopathology; D008264:Macrophages / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000502:physiology; D009569:Nitric Oxide / Q000502:physiology*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018124:Receptors, Tumor Necrosis Factor / Q000172:deficiency / Q000235:genetics; D012772:Shock, Septic / Q000503:physiopathology*; D013234:Stem Cells / Q000502:physiology
D017931:DNA Primers; D015850:Interleukin-6; D018124:Receptors, Tumor Necrosis Factor; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II