Type I interleukin-1 receptor is required for pulmonary responses to subacute ozone exposure in mice

Am J Respir Cell Mol Biol. 2007 Oct;37(4):477-84. doi: 10.1165/rcmb.2006-0315OC. Epub 2007 Jun 15.

Abstract

Interleukin (IL)-1, a proinflammatory cytokine, is expressed in the lung after ozone (O(3)) exposure. IL-1 mediates its effects through the type I IL-1 receptor (IL-1RI), the only signaling receptor for both IL-1alpha and IL-1beta. The purpose of this study was to determine the role of IL-1RI in pulmonary responses to O(3.) To that end, wild-type, C57BL/6 (IL-1RI(+/+)) mice and IL-1RI-deficient (IL-1RI(-/-)) mice were exposed to O(3) either subacutely (0.3 ppm for 72 h) or acutely (2 ppm for 3 h). Subacute O(3) exposure increased bronchoalveolar lavage fluid (BALF) protein, interferon-gamma-inducible protein (IP)-10, soluble tumor necrosis factor receptor 1 (sTNFR1), and neutrophils in IL-1RI(+/+) and IL-1RI(-/-) mice. With the exception of IP-10, all outcome indicators were reduced in IL-1RI(-/-) mice. Furthermore, subacute O(3) exposure increased IL-6 mRNA expression in IL-1RI(+/+), but not IL-1RI(-/-) mice. Acute (2 ppm) O(3) exposure increased BALF protein, IL-6, eotaxin, KC, macrophage inflammatory protein (MIP)-2, IP-10, monocyte chemotactic protein-1, sTNFR1, neutrophils, and epithelial cells in IL-1RI(+/+) and IL-1RI(-/-) mice. For IL-6, eotaxin, MIP-2, and sTNFR1, there were small but significant reductions of these outcome indicators in IL-1RI(-/-) versus IL-1RI(+/+) mice at 6 hours after exposure, but not at other time points, whereas other outcome indicators were unaffected by IL-1RI deficiency. These results suggest that IL-1RI is required for O(3)-induced pulmonary inflammation during subacute O(3) exposure, but plays a more minor role during acute O(3) exposure. In addition, these results suggest that the induction of IL-6 via IL-1RI may be important in mediating the effects of O(3) during subacute exposure.

Publication types

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

MeSH terms

  • Animals
  • Bronchoalveolar Lavage Fluid / cytology
  • Cell Count
  • Female
  • Gene Expression Regulation / drug effects
  • Inflammation
  • Intercellular Adhesion Molecule-1 / genetics
  • Intercellular Adhesion Molecule-1 / metabolism
  • Interleukin-1alpha / genetics
  • Interleukin-1alpha / metabolism
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Lung / drug effects*
  • Lung / metabolism*
  • Lung / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Ozone / pharmacology*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Interleukin-1 Type I / deficiency
  • Receptors, Interleukin-1 Type I / metabolism*
  • Respiration / drug effects

Substances

  • Interleukin-1alpha
  • Interleukin-1beta
  • Interleukin-6
  • RNA, Messenger
  • Receptors, Interleukin-1 Type I
  • Intercellular Adhesion Molecule-1
  • Ozone