Open AccessFebrile-range temperature modifies cytokine gene expression in LPS-stimulated macrophages by differentially modifying NF-κB recruitment to cytokine gene promoters
Author(s) -
Zachary A. Cooper,
Arundhati Ghosh,
Aditi Gupta,
Tapan Maity,
Ivor J. Benjamin,
Stefanie N. Vogel,
Jeffrey D. Hasday,
Ishwar Singh
Publication year - 2010
Publication title -
american journal of physiology. cell physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.432
H-Index - 181
eISSN - 1522-1563
pISSN - 0363-6143
DOI - 10.1152/ajpcell.00346.2009
Subject(s) - cytokine , chromatin immunoprecipitation , signal transduction , promoter , biology , hsf1 , gene expression , p38 mitogen activated protein kinases , microbiology and biotechnology , mapk/erk pathway , regulation of gene expression , nf κb , tumor necrosis factor alpha , cancer research , chemistry , gene , immunology , heat shock protein , hsp70 , biochemistry
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.