Interleukin-1β mediates macrophage-induced impairment of insulin signaling in human primary adipocytes

Am J Physiol Endocrinol Metab. 2014 Aug 1;307(3):E289-304. doi: 10.1152/ajpendo.00430.2013. Epub 2014 Jun 10.


Adipose tissue expansion during obesity is associated with increased macrophage infiltration. Macrophage-derived factors significantly alter adipocyte function, inducing inflammatory responses and decreasing insulin sensitivity. Identification of the major factors that mediate detrimental effects of macrophages on adipocytes may offer potential therapeutic targets. IL-1β, a proinflammatory cytokine, is suggested to be involved in the development of insulin resistance. This study investigated the role of IL-1β in macrophage-adipocyte cross-talk, which affects insulin signaling in human adipocytes. Using macrophage-conditioned (MC) medium and human primary adipocytes, we examined the effect of IL-1β antagonism on the insulin signaling pathway. Gene expression profile and protein abundance of insulin signaling molecules were determined, as was the production of proinflammatory cytokine/chemokines. We also examined whether IL-1β mediates MC medium-induced alteration in adipocyte lipid storage. MC medium and IL-1β significantly reduced gene expression and protein abundance of insulin signaling molecules, including insulin receptor substrate-1, phosphoinositide 3-kinase p85α, and glucose transporter 4 and phosphorylation of Akt. In contrast, the expression and release of the proinflammatory markers, including IL-6, IL-8, monocyte chemotactic protein-1, and chemokine (C-C motif) ligand 5 by adipocytes were markedly increased. These changes were significantly reduced by blocking IL-1β activity, its receptor binding, or its production by macrophages. MC medium-inhibited expression of the adipogenic factors and -stimulated lipolysis was also blunted with IL-1β neutralization. We conclude that IL-1β mediates, at least in part, the effect of macrophages on insulin signaling and proinflammatory response in human adipocytes. Blocking IL-1β could be beneficial for preventing obesity-associated insulin resistance and inflammation in human adipose tissue.

Keywords: IL-1β; cytokines; human adipocytes; insulin signaling; macrophages.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes, White / cytology
  • Adipocytes, White / drug effects*
  • Adipocytes, White / immunology
  • Adipocytes, White / metabolism
  • Antibodies, Neutralizing / pharmacology
  • Caspase 1 / chemistry
  • Caspase 1 / metabolism
  • Caspase Inhibitors / pharmacology
  • Cell Communication
  • Cell Line
  • Cells, Cultured
  • Culture Media, Conditioned / chemistry
  • Culture Media, Conditioned / metabolism
  • Gene Expression Regulation / drug effects
  • Humans
  • Hypoglycemic Agents / pharmacology*
  • Insulin / pharmacology*
  • Insulin Resistance*
  • Interleukin 1 Receptor Antagonist Protein / genetics
  • Interleukin 1 Receptor Antagonist Protein / metabolism
  • Interleukin-1beta / antagonists & inhibitors
  • Interleukin-1beta / metabolism*
  • Lipolysis / drug effects
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / immunology
  • Macrophages / metabolism*
  • Receptors, Interleukin-1 / agonists
  • Receptors, Interleukin-1 / antagonists & inhibitors
  • Receptors, Interleukin-1 / metabolism
  • Recombinant Proteins / metabolism
  • Signal Transduction*


  • Antibodies, Neutralizing
  • Caspase Inhibitors
  • Culture Media, Conditioned
  • Hypoglycemic Agents
  • IL1B protein, human
  • IL1RN protein, human
  • Insulin
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1beta
  • Receptors, Interleukin-1
  • Recombinant Proteins
  • Caspase 1