Colchicine has opposite effects on interleukin-1 beta and tumor necrosis factor-alpha production.
To study the role of microtubules in cytokine production, the effect of the microtubule depolymerizing agent colchicine on lipopolysaccharide endotoxin (LPS)-induced interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) release by blood monocytes and alveolar macrophages were examined. Immunofluorescence microscopy demonstrated that LPS resulted in the appearance of microtubule-containing cytoplasmic appendages and that colchicine, which resulted in microtubule disruption in monocytes, blocked appendage formation. Colchicine resulted in approximately 50% increase in LPS-induced IL-1 beta release and a 50% decrease in LPS-induced TNF-alpha release by human monocytes at all doses of LPS tested. Although colchicine resulted in a statistically significant increase in LPS-stimulated human alveolar macrophage IL-1 beta release, the increase was not as great as that observed with monocytes. Northern blot analysis suggested that the colchicine effect occurs pretranslationally because colchicine caused an increase in LPS-stimulated IL-1 beta mRNA levels and a decrease in TNF-alpha mRNA levels. These results suggest that microtubules contribute to the regulation of endotoxin-stimulated mononuclear phagocyte cytokine production and that this regulation differs significantly between IL-1 beta and TNF-alpha.
Department of Internal Medicine, Ohio State University, Columbus 43210.
J N
JN
Allen
D J
DJ
Herzyk
M D
MD
Wewers
D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D008070:Lipopolysaccharides / Q000502:physiology; D008264:Macrophages / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics
D007375:Interleukin-1; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D003078:Colchicine