Interleukin 10 inhibits interferon gamma- and tumor necrosis factor alpha-stimulated activation of NADPH oxidase 1 in human colonic epithelial cells and the mouse colon

J Gastroenterol. 2009;44(12):1172-84. doi: 10.1007/s00535-009-0119-6. Epub 2009 Aug 28.


Background: NADPH oxidase 1 (Nox1) is preferentially expressed in the colon, but its functional role is not fully understood. This study was designed to elucidate a potential role of Nox1 in inflammation of the colon.

Methods: Superoxide production by T84 cells was measured by the cytochrome c method. Protein and mRNA levels of Nox1 and Nox organizer 1 (NOXO1) in the cells were measured by real-time reverse transcriptase PCR and Western blotting, respectively. Expression of Nox1, Nox2, dual oxidase 2 (Duox2), NOXO1, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha mRNAs was measured in proximal, middle, and distal portions of colonic mucosas from male wild-type C57BL/6J and interleukin (IL)-10 knockout mice at 6, 10, and 16 weeks of age. Grading of inflammation was done by scoring histological changes.

Results: IL-10 significantly inhibited IFN-gamma- or TNF-alpha-induced up-regulation of superoxide-producing activity in T84 cells by suppressing expression of Nox1 mRNA and protein. IL-10 also inhibited TNF-alpha-stimulated induction of NOXO1 and p38 MAPK phosphorylation. Levels of Nox1, but not Nox2 or Duox2 mRNA, was age-dependently increased following a gradient with low levels in the proximal colon and high levels in the distal colon of the wild-type mice. The absence of IL-10 significantly facilitated Nox1 expression in association with increased IFN-gamma mRNA expression before the development of spontaneous colitis and age-dependently accelerated their mRNA expression.

Conclusions: IL-10 may be a possible down-regulator of the Nox1-based oxidase in the colon, suggesting a potential role of reactive oxygen species (ROS) derived from Nox1-based oxidase in inflammation of the colon.

MeSH terms

  • Animals
  • Cells, Cultured
  • Colitis / genetics
  • Colon / enzymology
  • Colon / metabolism
  • Epithelial Cells / enzymology
  • Epithelial Cells / metabolism
  • Humans
  • Interferon-gamma / antagonists & inhibitors*
  • Interferon-gamma / genetics
  • Interferon-gamma / metabolism
  • Interleukin-10 / genetics
  • Interleukin-10 / metabolism
  • Interleukin-10 / pharmacology*
  • Interleukin-10 Receptor alpha Subunit / genetics
  • Interleukin-10 Receptor alpha Subunit / metabolism
  • Interleukin-10 Receptor beta Subunit / genetics
  • Interleukin-10 Receptor beta Subunit / metabolism
  • Male
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NADH, NADPH Oxidoreductases / genetics
  • NADH, NADPH Oxidoreductases / metabolism*
  • NADPH Oxidase 1
  • NADPH Oxidase 2
  • NADPH Oxidases / genetics
  • NADPH Oxidases / metabolism
  • RNA, Messenger / metabolism
  • Superoxides / metabolism
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism


  • Interleukin-10 Receptor alpha Subunit
  • Interleukin-10 Receptor beta Subunit
  • Membrane Glycoproteins
  • RNA, Messenger
  • Tumor Necrosis Factor-alpha
  • Superoxides
  • Interleukin-10
  • Interferon-gamma
  • NADH, NADPH Oxidoreductases
  • Cybb protein, mouse
  • NADPH Oxidase 1
  • NADPH Oxidase 2
  • NADPH Oxidases
  • NOX1 protein, mouse
  • p38 Mitogen-Activated Protein Kinases