LITAF mediation of increased TNF-α secretion from inflamed colonic lamina propria macrophages

PLoS One. 2011;6(9):e25849. doi: 10.1371/journal.pone.0025849. Epub 2011 Sep 30.

Abstract

Dysregulation of TNF-α in lamina propria macrophages (LPM) is a feature of inflammatory bowel diseases (IBD). LPS-Induced-TNF-Alpha-Factor (LITAF) is a transcription factor that mediates TNF-α expression. To determine whether LITAF participates in the mediation of TNF-α expression in acutely inflamed colonic tissues, we first established the TNBS-induced colonic inflammation model in C57BL/6 mice. LPM were harvested from non-inflamed and inflamed colonic tissue and inflammatory parameters TNF-α and LITAF mRNA and protein levels were measured ex-vivo. LPM from TNBS-treated mice secreted significantly more TNF-α at basal state and in response to LPS than LPM from untreated mice (p<0.05). LITAF mRNA and protein levels were elevated in LPM from TNBS compared with untreated animals and LPS further increased LITAF protein levels in LPM from inflamed tissue (P<0.05). To further confirm the role of LITAF in acutely inflamed colonic tissues, TNBS-induced colonic inflammation was produced in LITAF macrophage specific knockout mice (LITAF mac -/- mice) and compared to wild type (WT) C57BL/6. Twenty four hours following TNBS administration, colonic tissue from LITAF mac -/- mice had less MPO activity and reduced colonic TNF-α mRNA then WT C57BL/6 mice (p<0.05). LPM harvested from LITAF mac -/- secreted significantly less TNF-α in response to LPS than wild type (WT) C57BL/6 (p<0.05). This study provides evidence that LITAF contributes to the regulation of TNF-α in LPM harvested following acute inflammation or LPS treatment paving the way for future work focusing on LITAF inhibitors in the treatment of TNF-α-mediated inflammatory conditions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Colon / cytology*
  • Colon / drug effects
  • Colon / metabolism*
  • DNA-Binding Proteins
  • Enzyme-Linked Immunosorbent Assay
  • Inflammation / chemically induced
  • Inflammation / metabolism*
  • Lipopolysaccharides / pharmacology
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mucous Membrane / cytology*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Peroxidase / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • DNA-Binding Proteins
  • Lipopolysaccharides
  • Litaf protein, mouse
  • Nuclear Proteins
  • Transcription Factors
  • Tumor Necrosis Factor-alpha
  • Peroxidase