Interleukin-1 receptor-associated kinase-3 is a key inhibitor of inflammation in obesity and metabolic syndrome

PLoS One. 2012;7(1):e30414. doi: 10.1371/journal.pone.0030414. Epub 2012 Jan 17.

Abstract

Background: Visceral obesity is associated with the rising incidence of type 2 diabetes and metabolic syndrome. Low-grade chronic inflammation and oxidative stress synergize in obesity and obesity-induced disorders.

Objective: We searched a cluster of molecules that support interactions between these stress conditions in monocytes.

Methods: RNA expressions in blood monocytes of two independent cohorts comprising 21 and 102 obese persons and 46 age-matched controls were determined by microarray and independently validated by quantitative RT-PCR analysis. The effect of three-month weight loss after bariatric surgery was determined. The effect of RNA silencing on inflammation and oxidative stress was studied in human monocytic THP-1 cells.

Results: Interleukin-1 receptor-associated kinase-3 (IRAK3), key inhibitor of IRAK/NFκB-mediated chronic inflammation, is downregulated in monocytes of obese persons. Low IRAK3 was associated with high superoxide dismutase-2 (SOD2), a marker of mitochondrial oxidative stress. A comparable expression profile was also detected in visceral adipose tissue of the same obese subjects. Low IRAK3 and high SOD2 was associated with a high prevalence of metabolic syndrome (odds ratio: 9.3; sensitivity: 91%; specificity: 77%). By comparison, the odds ratio of high-sensitivity C-reactive protein, a widely used marker of systemic inflammation, was 4.3 (sensitivity: 69%; specificity: 66%). Weight loss was associated with an increase in IRAK3 and a decrease in SOD2, in association with a lowering of systemic inflammation and a decreasing number of metabolic syndrome components. We identified the increase in reactive oxygen species in combination with obesity-associated low adiponectin and high glucose and interleukin-6 as cause of the decrease in IRAK3 in THP-1 cells in vitro.

Conclusion: IRAK3 is a key inhibitor of inflammation in association with obesity and metabolic syndrome. Our data warrant further evaluation of IRAK3 as a diagnostic and prognostic marker, and as a target for intervention.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipocytes / metabolism
  • Adipogenesis / genetics
  • Adult
  • Cell Line
  • Cells, Cultured
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / genetics
  • Diabetes Mellitus, Type 2 / metabolism
  • Female
  • Gene Expression Profiling
  • Humans
  • Inflammation / genetics*
  • Inflammation / metabolism
  • Interleukin-1 Receptor-Associated Kinases / blood
  • Interleukin-1 Receptor-Associated Kinases / genetics*
  • Interleukin-1 Receptor-Associated Kinases / metabolism
  • Intra-Abdominal Fat / metabolism
  • Male
  • Metabolic Syndrome / complications
  • Metabolic Syndrome / genetics*
  • Metabolic Syndrome / metabolism
  • Middle Aged
  • Monocytes / metabolism
  • Obesity / complications
  • Obesity / genetics*
  • Obesity / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Oxidative Stress
  • Reactive Oxygen Species / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / genetics
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism

Substances

  • Reactive Oxygen Species
  • Superoxide Dismutase
  • superoxide dismutase 2
  • IRAK3 protein, human
  • Interleukin-1 Receptor-Associated Kinases

Associated data

  • GEO/GSE32575