IL-33, a recently identified interleukin-1 gene family member, is expressed in human adipocytes.
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.
Wood
I Stuart
IS
University Clinical Department, Obesity Biology Research Unit, School of Clinical Sciences, Royal Liverpool University Hospital, University of Liverpool, Liverpool, UK. i.s.wood@liverpool.ac.uk
Wang
Bohan
B
Trayhurn
Paul
P
D017667:Adipocytes / Q000378:metabolism*; D052436:Adipose Tissue, White / Q000378:metabolism*; D002478:Cells, Cultured; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics*; D000067596:Interleukin-33; D007378:Interleukins / Q000235:genetics*; D017472:Receptors, Interleukin-1 / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology
C506536:IL33 protein, human; D007375:Interleukin-1; D000067596:Interleukin-33; D007378:Interleukins; D017472:Receptors, Interleukin-1; D014409:Tumor Necrosis Factor-alpha