Involvement of the 4-aminopyridine-sensitive transient A-type K+ current in macrophage-induced neuronal injury

Dehui Hu, Jianuo Liu, James Keblesh, Huangui Xiong

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

Through their capacity to secrete, upon activation, a variety of bioactive molecules, brain macrophages (and resident microglia) play an important role in brain immune and inflammatory responses. To test our hypothesis that activated macrophages induce neuronal injury by enhancing neuronal outward K+ current, we studied the effects of lipopolysaccharide (LPS)-stimulated human monocyte-derived macrophage (MDM) on neuronal transient A-type K+ current (IA) and resultant neuronal injury in primary rat hippocampal neuronal cultures. Bath application of LPS-stimulated MDM-conditioned media (MCM+) enhanced neuronal IA in a concentration-dependent manner. Non-stimulated MCM (MCM-) failed to alter IA. The enhancement of neuronal IA was recapitulated in neurons co-cultured with macrophages. The link of MCM(+)-induced enhancement of IA to MCM(+)-associated neuronal injury, as detected by propidium iodide and 4″,6-diamidino-2-phenylindol staining (DAPI) and 3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, was demonstrated by experimental results showing that addition of IA blocker 4-aminopyridine to the cultures protected hippocampal neurons from MCM(+)-induced neuronal injury. Further investigation revealed that glutamate was involved in MCM(+)-induced enhancement of neuronal IA. These results suggest that during brain inflammation macrophages (and microglia) might mediate neuronal injury via enhancement of neuronal IA, and that neuronal Kv channel might be a potential target for the development of therapeutic strategies for some neurodegenerative disorders by which immune and inflammatory responses are believed to be involved in the pathogenesis.

Original languageEnglish (US)
Pages (from-to)214-222
Number of pages9
JournalEuropean Journal of Neuroscience
Volume31
Issue number2
DOIs
StatePublished - Jan 2010

Keywords

  • Apoptosis
  • Glutamate
  • Hippocampus
  • Neuroinflammation
  • Potassium channels

ASJC Scopus subject areas

  • Neuroscience(all)

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