The P2X7-Egr pathway regulates nucleotide-dependent inflammatory gene expression in microglia
S A Friedle1, V M Brautigam, M Nikodemova
1Program in Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Glia
|September 30, 2010
Summary
The P2X7 receptor and mitogen-activated protein kinase (MAPK) pathway regulate microglial inflammatory responses. This pathway influences gene expression, offering potential for neuroprotective therapeutics targeting central nervous system (CNS) injury and disease.
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Microglial hyperactivity exacerbates neuronal damage in CNS disorders.
- P2X7 purinergic receptors modulate microglial inflammatory mediator release.
- The role of P2X7 receptors in inflammatory gene transcription remains unclear.
Purpose of the Study:
- To investigate the role of P2X7 receptors in regulating microglial inflammatory gene transcription.
- To identify the molecular mechanisms underlying P2X7 receptor-mediated transcriptional effects.
- To explore the therapeutic potential of P2X7 receptor modulation for neuroprotection.
Main Methods:
- Activation of P2X7 receptors using BzATP.
- Inhibition of MEK and p38 MAPK pathways.
- RNA interference (RNAi) to assess the necessity of Egr factors and P2X7 receptors.
- Measurement of inflammatory gene expression (iNOS, TNF-α, IL-6).
- Assessment of neuronal survival in LPS-conditioned medium.
Main Results:
- P2X7 receptor activation leads to the induction of early growth response (Egr)-1, -2, and -3 transcription factors.
- Egr factors and P2X7 receptors are essential for BzATP-induced changes in iNOS, TNF-α, and IL-6 gene expression.
- BzATP attenuates LPS-induced neuronal death, an effect dependent on P2X7 receptors.
Conclusions:
- Egr factors are novel downstream targets of P2X7 receptors in microglia.
- The MAPK-Egr pathway mediates P2X7 receptor effects on microglial inflammatory gene expression.
- P2X7 receptor activation exhibits neuroprotective effects by modulating microglial inflammatory responses.
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