IL-33, a Recently Identified interleukin-1 Gene Family Member, Is Expressed in Human Adipocytes

Biochem Biophys Res Commun. 2009 Jun 19;384(1):105-9. doi: 10.1016/j.bbrc.2009.04.081. Epub 2009 Apr 23.


Inflammation occurs in adipose tissue in obesity. We have examined whether IL-33, a recently identified IL-1 gene family member, and its associated receptors are expressed in human adipocytes. IL-33, IL-1RL1 and IL-1RAP gene expression was observed in human visceral white fat, in preadipocytes and in adipocytes (SGBS cells). Treatment with TNFalpha for 24h induced a 6-fold increase in IL-33 mRNA level in preadipocytes and adipocytes. Time-course studies with adipocytes showed that the increase in IL-33 mRNA with TNFalpha was maximal (>55-fold) at 12h. This response was markedly different to IL-1beta (peak mRNA increase at 2h; 5.4-fold) and 1L-18 (peak mRNA increase at 6h; >1500-fold). Exposure of adipocytes to hypoxia (1% O(2), 24h) did not alter IL-33 mRNA level; in preadipocytes, however, there was a 3-fold increase. Human adipocytes and preadipocytes express IL-33, but the various IL-1 family members exhibit major differences in responsiveness to TNFalpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism*
  • Adipose Tissue, White / metabolism*
  • Cells, Cultured
  • Gene Expression* / drug effects
  • Humans
  • Interleukin-1 / genetics*
  • Interleukin-33
  • Interleukins / genetics*
  • Receptors, Interleukin-1 / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology


  • IL33 protein, human
  • Interleukin-1
  • Interleukin-33
  • Interleukins
  • Receptors, Interleukin-1
  • Tumor Necrosis Factor-alpha