Differences in wound healing in mice with deficiency of IL-6 versus IL-6 receptor

J Immunol. 2010 Jun 15;184(12):7219-28. doi: 10.4049/jimmunol.0901929. Epub 2010 May 10.

Abstract

IL-6 modulates immune responses and is essential for timely wound healing. As the functions mediated by IL-6 require binding to its specific receptor, IL-6Ralpha, it was expected that mice lacking IL-6Ralpha would have the same phenotype as IL-6-deficient mice. However, although IL-6Ralpha-deficient mice share many of the inflammatory deficits seen in IL-6-deficient mice, they do not display the delay in wound healing. Surprisingly, mice with a combined deficit of IL-6 and IL-6Ralpha, or IL-6-deficient mice treated with an IL-6Ralpha-blocking Ab, showed improved wound healing relative to mice with IL-6 deficiency, indicating that the absence of the receptor contributed to the restoration of timely wound healing, rather than promiscuity of IL-6 with an alternate receptor. Wounds in mice lacking IL-6 showed delays in macrophage infiltration, fibrin clearance, and wound contraction that were not seen in mice lacking IL-6Ralpha alone and were greatly reduced in mice with a combined deficit of IL-6 and IL-6Ralpha. MAPK activation-loop phosphorylation was elevated in wounds of IL-6Ralpha-deficient mice, and treatment of wounds in these mice with the MEK inhibitor U0126 resulted in a delay in wound healing suggesting that aberrant ERK activation may contribute to improved healing. These findings underscore a deeper complexity for IL-6Ralpha function in inflammation than has been recognized previously.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Blotting, Southern
  • Blotting, Western
  • Enzyme-Linked Immunosorbent Assay
  • Genotype
  • Immunohistochemistry
  • Interleukin-6 / deficiency*
  • Interleukin-6 / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Receptors, Interleukin-6 / deficiency*
  • Receptors, Interleukin-6 / immunology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / immunology
  • Skin / injuries
  • Skin / metabolism
  • Wound Healing / immunology*

Substances

  • Interleukin-6
  • Receptors, Interleukin-6