Inflammation Research

, Volume 54, Issue 5, pp 194–203

Anti-inflammatory effect of selective estrogen receptor modulators (SERMs) in microglial cells

  • T. Suuronen
  • T. Nuutinen
  • J. Huuskonen
  • J. Ojala
  • A. Thornell
  • A. Salminen
Original Research Paper

DOI: 10.1007/s00011-005-1343-z

Cite this article as:
Suuronen, T., Nuutinen, T., Huuskonen, J. et al. Inflamm. res. (2005) 54: 194. doi:10.1007/s00011-005-1343-z

Abstract.

Objective: Our aim was to study how different SERMs modulate the inflammatory responses induced by lipopolysaccharide (LPS) or unmethylated CpG-oligonucleotides in mouse and rat microglial cells.

Materials and methods: Inflammatory responses of mouse N9 microglial cells and rat primary hippocampal microglia to lipopolysaccharide (LPS) exposure were recorded by the secretion of nitric oxide (NO) and cytokine IL-6 in two models where SERM was added either 24 h before LPS addition or simultaneously or even after the LPS exposure. The responses of 17β-estradiol, tamoxifen, raloxifene and ICI 182.780 were compared. Responses were recorded by ELISA, Northern and EMSA assays.

Results: SERMs but not 17β-estradiol induced a significant, concentration-dependent anti-inflammatory response both in rat primary microglial cells and in mouse N9 microglial cells. The response was observed both in NO and IL-6 secretion as well as in total IL-6 mRNA expression. We have recently observed that histone deacetylase (HDAC) inhibitors can potentiate the LPS-induced inflammatory response. Raloxifene and tamoxifen inhibited the potentiation of LPS response induced by trichostatin A, an HDAC inhibitor, in N9 microglia. A SERM-induced anti-inflammatory response was observed in acute models where SERM was added simultaneously or even up to 6 h later than LPS exposure. In contrast, the pretreatment of N9 microglia with tamoxifen or raloxifene for 30 h before LPS exposure did not provide any protection against the LPS response. We also observed that the raloxifene-induced protection in N9 microglia was connected to a decline of LPS-induced DNAbinding activity of AP-1 but not that of NF-κB transcription factors.

Conclusions: Our results show that tamoxifen, raloxifene and ICI 182.780 induce an anti-inflammatory response in acute models of mouse and rat microglial cells. It seems that this response is not estrogen receptor -mediated but, probably, is attributable to some SERM-induced modulation of LPS-activated pro-inflammatory signalling cascades.

Key words.

EstrogenLipopolysaccharideInnate immunityNeuroinflammationHDAC

Copyright information

© Birkhäuser Verlag, Basel 2005

Authors and Affiliations

  • T. Suuronen
    • 1
  • T. Nuutinen
    • 1
  • J. Huuskonen
    • 1
  • J. Ojala
    • 1
  • A. Thornell
    • 2
  • A. Salminen
    • 1
    • 3
  1. 1.Department of Neuroscience and NeurologyUniversity of KuopioKuopioFinland
  2. 2.Department of Biochemistry and Biophysics, ALBA NOVAUniversity of StockholmStockholmSweden
  3. 3.Department of NeurologyKuopio University HospitalKuopioFinland