Febrile-range temperature modifies cytokine gene expression in LPS-stimulated macrophages by differentially modifying NF-{kappa}B recruitment to cytokine gene promoters.
We previously showed that exposure to febrile-range temperatures (FRT, 39.5-40 degrees C) reduces LPS-induced TNF-alpha expression, in part through the direct interaction of heat shock factor-1 (HSF1) with the TNF-alpha gene promoter. However, it is not known whether exposure to FRT also modifies more proximal LPS-induced signaling events. Using HSF1-null mice, we confirmed that HSF1 is required for FRT-induced repression of TNF-alpha in vitro by LPS-stimulated bone marrow-derived macrophages and in vivo in mice challenged intratracheally with LPS. Exposing LPS-stimulated RAW 264.7 mouse macrophages to FRT reduced TNF-alpha expression while increasing IL-1beta expression despite the two genes sharing a common myeloid differentiation protein-88 (MyD88)-dependent pathway. Global activation of the three LPS-induced signaling intermediates that lead to cytokine gene expression, ERK and p38 MAPKs and NF-kappaB, was not affected by exposing RAW 264.7 cells to FRT as assessed by ERK and p38 phosphorylation and NF-kappaB in vitro DNA-binding activity and activation of a NF-kappaB-dependent synthetic promoter. However, chromatin immunoprecipitation (ChIP) analysis demonstrated that exposure to FRT reduced LPS-induced recruitment of NF-kappaB p65 to the TNF-alpha promoter while simultaneously increasing its recruitment to the IL-1beta promoter. These data suggest that FRT exerts its effects on cytokine gene expression in a gene-specific manner through distal effects on promoter activation rather than proximal receptor activation and signal transduction.
Univ. of Maryland School of Medicine, Health Science Facility-II, Rm. S311, 20 Penn St., Baltimore, MD 21201,USA.
Zachary A
ZA
Cooper
Arundhati
A
Ghosh
Aditi
A
Gupta
Tapan
T
Maity
Ivor J
IJ
Benjamin
Stefanie N
SN
Vogel
Jeffrey D
JD
Hasday
Ishwar S
IS
Singh
D000818:Animals; D002843:Chromatin / Q000502:physiology; D003433:Crosses, Genetic; D016207:Cytokines / Q000235:genetics*; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000502:physiology; D005260:Female; D005334:Fever / Q000503:physiopathology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D000076249:Heat Shock Transcription Factors; D053583:Interleukin-1beta / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000502:physiology*; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D013696:Temperature; D014157:Transcription Factors / Q000172:deficiency / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D002843:Chromatin; D016207:Cytokines; D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; C490017:Hsf1 protein, mouse; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D016328:NF-kappa B; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D004247:DNA