Abstract Background Particulate air pollution has Irrigation Sleeves been associated with lung and cardiovascular disease, for which lung inflammation may be a driving mechanism.The pro-inflammatory cytokine, tumor necrosis factor (TNF) has been suggested to have a key-role in particle-induced inflammation.We studied the time course of gene expression of inflammatory markers in the lungs of wild type mice and Tnf-/- mice after exposure to diesel exhaust particles (DEPs).
Mice were exposed to either a single or multiple doses of DEP by inhalation.We measured the mRNA level of the cytokines Tnf and interleukin-6 (Il-6) and the chemokines, monocyte chemoattractant protein (Mcp-1), macrophage inflammatory protein-2 (Mip-2) and keratinocyte LED Visor derived chemokine (Kc) in the lung tissue at different time points after exposure.Results Tnf mRNA expression levels increased late after DEP-inhalation, whereas the expression levels of Il-6, Mcp-1 and Kc increased early.
The expression of Mip-2 was independent of TNF if the dose was above a certain level.The expression levels of the cytokines Kc, Mcp-1 and Il-6, were increased in the absence of TNF.Conclusion Our data demonstrate that Tnf is not important in early DEP induced inflammation and rather exerts negative influence on Mcp-1 and Kc mRNA levels.
This suggests that other signalling pathways are important, a candidate being one involving Mcp-1.