RGD-peptide lunasin inhibits Akt-mediated NF-κB activation in human macrophages through interaction with the αVβ3 integrin

Mol Nutr Food Res. 2012 Oct;56(10):1569-81. doi: 10.1002/mnfr.201200301. Epub 2012 Sep 4.

Abstract

Scope: Cardiovascular disease is the leading cause of mortality in the United States and regulation of aberrant macrophage activity under inflammatory conditions is critical for its prevention. The objective was to determine the effect of lunasin on the inhibition of Akt-mediated activation of nuclear factor-kappa B (NF-κB)-dependent markers of inflammation and to characterize the physical interaction of lunasin with the αVβ3 integrin receptor in lipopolysaccharide (LPS)-induced human THP-1 macrophages.

Methods and results: The effect of lunasin was evaluated in vitro in LPS-induced THP-1 human macrophages using immunoassays, co-immunoprecipitation (Co-IP), and fluorescence confocal microscopy. Lunasin (50 μM) reduced cyclooxygenase-2, inducible nitric oxide synthase, and NO levels by 57.9, 64.5, and 76.2%, respectively, and inhibited the activation of phosphorylated Akt and NF-κB p65 by 59.5 and 74.5%, respectively. Lunasin (50 μM) reduced exogenous release of prostaglandin E(2) and tumor necrosis factor-α by 92.5 and 94.9%, respectively. Vitronectin (10 μg/mL), an integrin ligand, increased expression of proinflammatory markers, whereas lunasin (50 μM) attenuated them. Co-IP of lunasin-treated cells confirmed direct interaction with αVβ3 integrin and LC/MS/MS verified its identity. Lunasin was detected within intracellular vesicles and reduced total αVβ3 intensity as observed by fluorescence microscopy.

Conclusion: Lunasin inhibited αVβ3 integrin-mediated proinflammatory markers and downregulated Akt-mediated NF-κB pathways through interaction with αVβ3 integrin.

MeSH terms

  • Cell Line
  • Cell Proliferation / drug effects
  • Cyclooxygenase 2 / genetics
  • Cyclooxygenase 2 / metabolism
  • Humans
  • Immunoprecipitation
  • Inflammation / immunology
  • Inflammation / physiopathology
  • Integrin alphaVbeta3 / immunology
  • Integrin alphaVbeta3 / metabolism*
  • Lipopolysaccharides / metabolism
  • Macrophages / drug effects
  • Microscopy, Confocal
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / genetics
  • NF-kappa B / metabolism*
  • Nitric Oxide
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism
  • Oligopeptides / pharmacology*
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction
  • Soybean Proteins / pharmacology*
  • Tandem Mass Spectrometry
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / metabolism
  • Vitronectin / pharmacology

Substances

  • GM2S-1 protein, Glycine max
  • Integrin alphaVbeta3
  • Lipopolysaccharides
  • NF-kappa B
  • Oligopeptides
  • Soybean Proteins
  • Tumor Necrosis Factor-alpha
  • Vitronectin
  • Nitric Oxide
  • arginyl-glycyl-aspartic acid
  • NOS2 protein, human
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Proto-Oncogene Proteins c-akt