Suppression of LPS-induced tumor necrosis factor-alpha gene expression by microtubule disrupting agents.
Microtubule disrupting agents such as colchicine have been shown to reduce TNF-alpha production in macrophages. To examine molecular mechanisms underlying the action of colchicine, TNF-alpha gene expression was studied in the murine macrophage cell line PU5-1.8. An LPS stimulation caused an intense up-regulation of TNF-alpha gene expression which was followed by a high TNF-alpha protein production. Simultaneous addition of colchicine (10 microM) suppressed LPS-induced TNF-alpha mRNA accumulation by one-third and TNF-alpha protein release by two-thirds. This effect was shared by vinblastine and vincristine, chemically different agents that also disrupt microtubule polymerization. For full suppressive activity on TNF-alpha gene expression, colchicine had to be present for 3 h in LPS-stimulated macrophage cultures. With nuclear run-on transcription experiments we could demonstrate that colchicine primarily inhibited de novo gene transcription and did not accelerate degradation of TNF-alpha mRNA in actinomycin D-treated macrophages. Thus, the well-known antiinflammatory action of microtubule depolymerizing agents may be largely due to a reduced TNF-alpha gene expression.
Li
Z
Z
Institute of Immunology, Philipps University, Marburg, Germany.
Davis
G S
GS
Mohr
C
C
Nain
M
M
Gemsa
D
D
D000818:Animals; D002460:Cell Line; D003078:Colchicine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000276:immunology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008870:Microtubules / Q000187:drug effects*; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000235:genetics*; D014747:Vinblastine / Q000494:pharmacology; D014750:Vincristine / Q000494:pharmacology
D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D014750:Vincristine; D014747:Vinblastine; D003078:Colchicine