Divergence of canonical danger signals: the genome-level expression patterns of human mononuclear cells subjected to heat shock or lipopolysaccharide.
BACKGROUND
Peripheral blood mononuclear cells (PBMC) serve a sentinel role allowing the host to efficiently sense and adapt to the presence of danger signals. Herein we have directly compared the genome-level expression patterns (microarray) of a human PBMC model (THP-1 cells) subjected to one of two canonical danger signals, heat shock or lipopolysaccharide (LPS).


CONCLUSIONS
Based on sequential expression and statistical filters, and in comparison to control cells, we found that 3,988 genes were differentially regulated in THP-1 cells subjected to LPS stress, and 2,921 genes were differentially regulated in THP-1 cells subjected to heat shock stress. Venn analyses demonstrated that the majority of differentially regulated genes (> or = 70%) were uniquely expressed in response to one of the two danger signals. Functional analyses demonstrated that the two danger signals induced expression or repression of genes corresponding to unique pathways, molecular functions, biological processes, and gene networks. In contrast, there were 184 genes that were commonly upregulated by both stress signals, and 430 genes that were commonly downregulated by both stress signals. Interestingly, the 184 commonly upregulated genes corresponded to a gene network broadly related to inflammation, and more specifically to chemokine signaling.


CONCLUSIONS
These data demonstrate that the mononuclear cell responses to the canonical stress signals, heat shock and LPS, are highly divergent. However, there is a heretofore unrecognized common pattern of gene network expression corresponding to chemokine-related biology. The data also serve as a reference database for investigators in the field of stress signaling.
Wong
Hector R
HR
Department of Pediatrics, University of Cincinnati College of Medicine, Division of Critical Care Medicine, Cincinnati Children's Hospital Medical Center and Cincinnati Children's Research Foundation, Cincinnati, Ohio, USA. hector.wong@cchmc.org
Odoms
Kelli
K
Sakthivel
Bhuvaneswari
B
D002460:Cell Line; D003198:Computer Simulation; D016207:Cytokines / Q000235:genetics; D004926:Escherichia coli; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks / Q000187:drug effects / Q000276:immunology; D006360:Heat-Shock Proteins / Q000494:pharmacology*; D018869:Heat-Shock Response; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000187:drug effects / Q000276:immunology; D020411:Oligonucleotide Array Sequence Analysis; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology
D016207:Cytokines; D006360:Heat-Shock Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B