Differential pro-inflammatory responses of astrocytes and microglia involve STAT3 activation in response to 1800 MHz radiofrequency fields

PLoS One. 2014 Oct 2;9(9):e108318. doi: 10.1371/journal.pone.0108318. eCollection 2014.

Abstract

Microglia and astrocytes play important role in maintaining the homeostasis of central nervous system (CNS). Several CNS impacts have been postulated to be associated with radiofrequency (RF) electromagnetic fields exposure. Given the important role of inflammation in neural physiopathologic processes, we investigated the pro-inflammatory responses of microglia and astrocytes and the involved mechanism in response to RF fields. Microglial N9 and astroglial C8-D1A cells were exposed to 1800 MHz RF for different time with or without pretreatment with STAT3 inhibitor. Microglia and astrocytes were activated by RF exposure indicated by up-regulated CD11b and glial fibrillary acidic protein (GFAP). However, RF exposure induced differential pro-inflammatory responses in astrocytes and microglia, characterized by different expression and release profiles of IL-1β, TNF-α, IL-6, PGE2, nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Moreover, the RF exposure activated STAT3 in microglia but not in astrocytes. Furthermore, the STAT3 inhibitor Stattic ameliorated the RF-induced release of pro-inflammatory cytokines in microglia but not in astrocytes. Our results demonstrated that RF exposure differentially induced pro-inflammatory responses in microglia and astrocytes, which involved differential activation of STAT3 in microglia and astrocytes. Our data provide novel insights into the potential mechanisms of the reported CNS impacts associated with mobile phone use and present STAT3 as a promising target to protect humans against increasing RF exposure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / metabolism*
  • Astrocytes / pathology
  • CD11b Antigen / metabolism
  • Cell Line
  • Cyclooxygenase 2 / metabolism
  • Cytokines / genetics
  • Cytokines / metabolism
  • DNA / metabolism
  • Dinoprostone / biosynthesis
  • Electromagnetic Fields*
  • Gene Expression Profiling
  • Gene Expression Regulation
  • Glial Fibrillary Acidic Protein / metabolism
  • Inflammation / genetics
  • Inflammation / pathology*
  • Mice
  • Microglia / metabolism*
  • Microglia / pathology
  • Nitric Oxide / biosynthesis
  • Nitric Oxide Synthase Type II / metabolism
  • Phosphorylation
  • Protein Binding
  • Radio Waves*
  • STAT3 Transcription Factor / metabolism*

Substances

  • CD11b Antigen
  • Cytokines
  • Glial Fibrillary Acidic Protein
  • STAT3 Transcription Factor
  • Nitric Oxide
  • DNA
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2
  • Dinoprostone

Grants and funding

This work was supported by the National Basic Research Program of China (973 Program)( 2011CB503700) and the National Natural Science Foundation of China (31200627, 31170800). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.