Omentin-1 attenuates lipopolysaccharide (LPS)-induced U937 macrophages activation by inhibiting the TLR4/MyD88/NF-κB signaling

Arch Biochem Biophys. 2020 Jan 15:679:108187. doi: 10.1016/j.abb.2019.108187. Epub 2019 Nov 9.

Abstract

Macrophages play a pivotal role in the defense response against harmful pathogens and stimuli by releasing various pro-inflammatory mediators. However, overproduction of pro-inflammatory mediators will do harm to the organism and cause inflammation-associated diseases. Omentin-1, which is a newly discovered adipokine, is specifically expressed in omental adipose tissue. Recent studies have found correlations between omentin-1 and insulin resistance, diabetes, obesity, inflammation, atherosclerosis, bone metabolism, and tumor cell proliferation. Some studies have shown that the association between omentin-1, insulin resistance, and inflammation might suggest that omentin-1 plays an important role in chronic inflammatory diseases. In this study, we found that omentin-1 inhibited LPS-induced expression of inflammatory mediators and pro-inflammatory cytokines in macrophages. Furthermore, omentin-1 inhibited activation of the NF-κB pathway by suppressing both nuclear p65 accumulation and transfected NFκB promoter activity. Importantly, omentin-1 increased nuclear translocation of Nrf2. Our findings demonstrate that omentin-1 exerts anti-inflammatory effects on LPS-induced macrophages and has potential implication in the treatment of inflammation-associated diseases.

Keywords: Inflammation; LPS; Macrophage; NF-κB; Omentin-1.

MeSH terms

  • Cyclooxygenase 2 / metabolism
  • Cytokines / metabolism
  • Dinoprostone / metabolism
  • Gene Expression Regulation / drug effects
  • Humans
  • Lectins / pharmacology*
  • Lipopolysaccharides / pharmacology*
  • Macrophage Activation / drug effects*
  • Myeloid Differentiation Factor 88 / metabolism*
  • NF-E2-Related Factor 2 / metabolism
  • NF-kappa B / metabolism*
  • Nitric Oxide / biosynthesis
  • Nitric Oxide Synthase Type II / metabolism
  • Signal Transduction / drug effects*
  • Toll-Like Receptor 4 / metabolism*
  • U937 Cells

Substances

  • Cytokines
  • Lectins
  • Lipopolysaccharides
  • Myeloid Differentiation Factor 88
  • NF-E2-Related Factor 2
  • NF-kappa B
  • NFE2L2 protein, human
  • Toll-Like Receptor 4
  • Nitric Oxide
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2
  • Dinoprostone