AMPK activation inhibits expression of proinflammatory mediators through downregulation of PI3K/p38 MAPK and NF-κB signaling in murine macrophages

DNA Cell Biol. 2015 Feb;34(2):133-41. doi: 10.1089/dna.2014.2630. Epub 2014 Dec 23.

Abstract

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a central role in energy homeostasis and regulation of inflammatory responses. The present study is aimed to investigate the anti-inflammatory effects of ENERGI-F704, a nucleobase analogue isolated from bamboo leaves, on expression of proinflammatory mediators in murine macrophage RAW264.7 in response to lipopolysaccharide (LPS). ENERGI-F704 enhanced phosphorylation of AMPK(T172) but insignificantly affected the viability of RAW264.7 cells. Further investigation showed that ENERGI-F704 decreased mRNA expression of interleukin (IL)-6, IL-8, tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX2), and inducible nitric oxide synthase (iNOS) induced by LPS, as well as suppressed the production of prostaglandin E2 (PGE₂) and nitric oxide (NO). Additionally, the inhibitory effects of ENERGI-F704 on the LPS-induced proinflammatory mediators were diminished by pretreatment of AMPK inhibitor Compound C. ENERGI-F704 also inhibited LPS-triggered activation of nuclear factor kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K), and p38 mitogen-activated protein kinase (p38), whereas extracellular signal-regulated kinase (Erk)1/2 and c-Jun N-terminal kinase (JNK) were insignificantly influenced. Our findings indicate that ENERGI-F704 may exert anti-inflammatory activity on RAW264.7 cells in response to LPS through the activation of AMPK and suppression of PI3K/P38/NF-κB signaling and the consequent decreased expression of proinflammatory mediators, suggesting that ENERGI-F704 is beneficial to the amelioration of inflammatory disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Cell Line
  • Cell Survival / drug effects
  • Cytokines / genetics
  • Cytokines / metabolism
  • Down-Regulation / drug effects
  • Enzyme Activation / drug effects
  • Gene Expression / drug effects
  • Immunoblotting
  • Inflammation Mediators / metabolism*
  • Lipopolysaccharides / pharmacology
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • NF-kappa B / metabolism*
  • Phosphatidylinositol 3-Kinase / metabolism*
  • Phosphorylation / drug effects
  • Plant Extracts / pharmacology
  • Plant Leaves / chemistry
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sasa / chemistry
  • Signal Transduction / drug effects
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Cytokines
  • ENERGI-F704
  • Inflammation Mediators
  • Lipopolysaccharides
  • NF-kappa B
  • Plant Extracts
  • Phosphatidylinositol 3-Kinase
  • p38 Mitogen-Activated Protein Kinases
  • AMP-Activated Protein Kinases