Prediction of novel genes associated with negative regulators of toll-like receptors-induced inflammation based on endotoxin tolerance

Inflammation. 2012 Dec;35(6):1889-99. doi: 10.1007/s10753-012-9511-0.

Abstract

Prior exposure of innate immune cells to lipopolysaccharide (LPS) has caused them to be refractory to further endotoxin stimulation, also termed endotoxin tolerance (ET). Bacterial LPS signals through Toll-like receptor (TLR) 4, which was thought to enable the innate immune system to deal with invasive pathogens and to restrain systemic inflammation efficiently. We established a robust model of ET and determined the level of TNF-α and IL-6 in cultured human monocytes. Then, microarray assay was applied to assess gene expression in this model. The results showed that 356 non-tolerizable genes were differentially expressed at a high level in tolerant monocytes. The genes selected were classified into several categories based on gene ontology (GO) and KEGG pathway database. And then literature annotations, protein-protein interaction (PPI) network, and functional consistency were applied to analyze the non-tolerizable genes. Finally, the microarray results were verified by quantitative real-time PCR of seven representative genes, including the two candidate genes, Spry2 and Smurf2, which were supposed to play a critical role in TLRs-induced inflammation based on literature retrieval. Our results would provide useful information for further analysis of regulating TLRs-induced inflammation, and would facilitate the study of associated mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Cells, Cultured
  • Endotoxins / immunology*
  • Gene Expression
  • Gene Expression Profiling
  • Humans
  • Inflammation / genetics*
  • Interleukin-6 / analysis
  • Intracellular Signaling Peptides and Proteins
  • Leukocytes, Mononuclear / immunology*
  • Membrane Proteins / genetics
  • Protein Serine-Threonine Kinases
  • Signal Transduction / immunology
  • Toll-Like Receptor 4 / genetics*
  • Tumor Necrosis Factor-alpha / analysis
  • Ubiquitin-Protein Ligases / genetics

Substances

  • Adaptor Proteins, Signal Transducing
  • Endotoxins
  • Interleukin-6
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Tlr4 protein, mouse
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • Smurf2 protein, mouse
  • Ubiquitin-Protein Ligases
  • Protein Serine-Threonine Kinases
  • Spry2 protein, mouse