Decline in the expression of IL-2 after trauma and changes in the nuclear transcription factors NFAT and AP-1

Chin Med J (Engl). 2002 Sep;115(9):1348-51.

Abstract

Objective: To investigate whether the decrease in expression of interleukin-2 (IL-2) after trauma is associated with changes in DNA binding activity of nuclear factor of activated T cells (NFAT) and activator protein-1 (AP-1).

Methods: Mice with closed impact injury with fracture in both hind limbs were adopted as the trauma model. Spleen lymphocytes were isolated from traumatized mice and stimulated with Con-A. Culture supernatants were assayed for IL-2 activity, and total RNA was extracted from spleen lymphocytes and assayed for IL-2 mRNA. DNA binding activity of NFAT and AP-1 were measured by electrophoretic mobility shift assay (EMSA). The expression of c-Fos, c-Jun and JunB proteins was determined by the Western blot analysis.

Results: DNA binding activity of NFAT and AP-1 gradually decreased to a minimum of 41% and 49%, respectively, of the control on the 4th day after injury, which was closely followed by the decline in IL-2 activity and IL-2 mRNA. A decrease in the expression of c-Fos on the 1st and 4th day after trauma had no significant effect on c-Jun expression; the increase in expression of JunB was only on the 1st day after injury.

Conclusion: Decreased IL-2 expression is, at least in part, due to a decline in the activation of NFAT and AP-1 in traumatized mice. The decline in DNA binding activity of NFAT and AP-1 is partly due to a trauma-induced block in the expression of c-Fos.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Nucleus / chemistry
  • DNA / metabolism
  • DNA-Binding Proteins / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Female
  • Interleukin-2 / analysis
  • Interleukin-2 / genetics*
  • Male
  • Mice
  • NFATC Transcription Factors
  • Nuclear Proteins*
  • Proto-Oncogene Proteins c-fos / analysis
  • Proto-Oncogene Proteins c-jun / analysis
  • RNA, Messenger / analysis
  • Transcription Factor AP-1 / metabolism*
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • Interleukin-2
  • NFATC Transcription Factors
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-fos
  • Proto-Oncogene Proteins c-jun
  • RNA, Messenger
  • Transcription Factor AP-1
  • Transcription Factors
  • DNA