The attenuating effects of 1,2,3,4,6 penta-O-galloyl-β-d-glucose on pro-inflammatory responses of LPS/IFNγ-activated BV-2 microglial cells through NFƙB and MAPK signaling pathways

J Neuroimmunol. 2018 Nov 15:324:43-53. doi: 10.1016/j.jneuroim.2018.09.004. Epub 2018 Sep 11.

Abstract

Background: Overactivated microglial cells exhibit chronic inflammatory response and can lead to the continuous production of pro-inflammatory cytokines, perpetuating inflammation, and ultimately resulting in neuronal injury. 1,2,3,4,6-Penta-O-Galloyl-β-d-Glucose (PGG), which is a naturally occurring polyphenolic compound, has exhibited anti-inflammatory effect through the inhibition of many cytokines in different experimental models, but its effect on activated microglia cells was never described. In the present study, we investigated PGG effect in proteins involved in the NFƙB and MAPK signaling pathways, which play a central role in inflammation through their ability to induce transcription of pro-inflammatory genes.

Methods: PCR arrays and RT-PCR with individual primers were used to determine the effect of PGG on mRNA expression of genes involved in NFƙB and MAPK signaling pathways. Western blots were performed to confirm PCR results.

Results: The data obtained showed that PGG modulated the expression of 5 genes from the NFƙB (BIRC3, CHUK, IRAK1, NFƙB1, NOD1) and 2 genes from MAPK signaling pathway (CDK2 and MYC) when tested in RT-PCR assays. Western blots confirmed the PCR results at the protein level, showing that PGG attenuated the expression of total and phosphorylated proteins (CDK2, CHUK, IRAK1, and NFƙB1) involved in NFƙB and MAPK signaling.

Conclusion: These findings show that PGG could modulate the expression of genes and proteins involved in the production of pro-inflammatory cytokines in microglia cells.

Keywords: 1,2,3,4,6-penta-O-galloyl-β-d-glucose; Microglia cells; NFƙB and MAP kinase signaling pathways.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Line
  • Hydrolyzable Tannins / pharmacology*
  • Inflammation Mediators / antagonists & inhibitors
  • Inflammation Mediators / metabolism*
  • Interferon-gamma / toxicity*
  • Lipopolysaccharides / toxicity*
  • MAP Kinase Signaling System / drug effects
  • MAP Kinase Signaling System / physiology*
  • Mice
  • Microglia / drug effects
  • Microglia / metabolism*
  • NF-kappa B / metabolism*

Substances

  • Hydrolyzable Tannins
  • Inflammation Mediators
  • Lipopolysaccharides
  • NF-kappa B
  • pentagalloylglucose
  • Interferon-gamma