Genkwanin inhibits proinflammatory mediators mainly through the regulation of miR-101/MKP-1/MAPK pathway in LPS-activated macrophages

PLoS One. 2014 May 6;9(5):e96741. doi: 10.1371/journal.pone.0096741. eCollection 2014.

Abstract

Genkwanin is one of the major non-glycosylated flavonoids in many herbs with anti-inflammatory activities. Although its anti-inflammatory activity in vivo has been reported, the potential molecular mechanisms remain obscure. In this study, by pharmacological and genetic approaches, we explore the anti-inflammatory effects of genkwanin in LPS-activated RAW264.7 macrophages. Genkwanin potently decreases the proinflammatory mediators, such as iNOS, TNF-α, IL-1β and IL-6, at the transcriptional and translational levels without cytotoxicity, indicating the excellent anti-inflammatory potency of genkwanin in vitro. Mechanism study shows that genkwanin significantly suppresses the p38- and JNK-mediated AP-1 signaling pathway and increases the mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) expression at the posttranscriptional level. We also confirmed that microRNA-101 (miR-101) is a negative regulator of MKP-1 expression. Moreover, regardless of miR-101-deficient cells or miR-101-abundant cells, the suppression effects of genkwanin on supernatant proinflammatory mediators' levels are far less than that in respective negative control cells, suggesting that genkwanin exerts anti-inflammatory effect mainly through reducing miR-101 production. However, genkwanin can't affect the level of phospho-Akt (p-Akt), indicating that the phosphorylation of Akt may be not responsible for the effect of genkwanin on miR-101 production. We conclude that genkwanin exerts its anti-inflammatory effect mainly through the regulation of the miR-101/MKP-1/MAPK pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / chemistry
  • Anti-Inflammatory Agents / pharmacology*
  • Cell Line
  • Dual Specificity Phosphatase 1 / metabolism
  • Flavones / chemistry
  • Flavones / pharmacology*
  • Inflammation Mediators / antagonists & inhibitors
  • Inflammation Mediators / metabolism*
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / toxicity
  • Macrophages / cytology
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Mice
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / metabolism
  • Mitogen-Activated Protein Kinases / metabolism
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type II / genetics
  • Nitric Oxide Synthase Type II / metabolism
  • Oligonucleotides, Antisense / metabolism
  • Phosphorylation
  • Signal Transduction / drug effects*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Up-Regulation / drug effects

Substances

  • Anti-Inflammatory Agents
  • Flavones
  • Inflammation Mediators
  • Interleukin-1beta
  • Interleukin-6
  • Lipopolysaccharides
  • MIRN101 microRNA, mouse
  • MicroRNAs
  • Oligonucleotides, Antisense
  • Tumor Necrosis Factor-alpha
  • Nitric Oxide
  • genkwanin
  • Nitric Oxide Synthase Type II
  • Mitogen-Activated Protein Kinases
  • Dual Specificity Phosphatase 1
  • Dusp1 protein, mouse

Grants and funding

This work was supported by the National Natural Science Foundation of China (Nos. 81274163 and 81173645) and National S&T Major Project and Scientific Researchers Aiding Enterprise Item (Nos. 2012ZX09301-002-001 and 2014ZX09201022-006) from the Ministry of Science and Technology of the People's Republic of China. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.