Involvement of P2X4 receptors in hippocampal microglial activation afterstatus epilepticus
Abstract
Within the central nervous system, functions of the ATP-gated receptor-channel P2X4 (P2X4R) are still poorly understood, yet P2X4R activation in neurons and microglia coincides with high or pathological neuronal activities. In this study, we investigated the potential involvement of P2X4R in microglial functions in a model of kainate (KA)-induced status epilepticus (SE). We found that SE was associated with an induction of P2X4R expression in the hippocampus, mostly localized in activated microglial cells. In P2X4R-deficient mice, behavioral responses during KA-induced SE were unaltered. However, 48h post SE specific features of microglial activation, such as cell recruitment and upregulation of voltage-dependent potassium channels were impaired in P2X4R-deficient mice, whereas the expression and function of other microglial purinergic receptors remained unaffected. Consistent with the role of P2X4R in activity-dependent degenerative processes, the CA1 area was partially protected from SE-induced neuronal death in P2X4R-deficient mice compared with wild-type animals. Our findings demonstrate that P2X4Rs are brought into play during neuronal hyperexcitability and that they control specific aspects of microglial activation. Our results also suggest that P2X4Rs contribute to excitotoxic damages by regulating microglial activation. GLIA 2013;61:1306–1319Keywords
This publication has 38 references indexed in Scilit:
- CCL2 promotes P2X4 receptor trafficking to the cell surface of microgliaPurinergic Signalling, 2012
- Physiology of MicrogliaPhysiological Reviews, 2011
- Neuronal CCL21 up‐regulates microglia P2X4 expression and initiates neuropathic pain developmentThe EMBO Journal, 2011
- Microglia–neuronal signalling in neuropathic pain hypersensitivity 2.0Current Opinion in Neurobiology, 2010
- P2X4 receptors mediate PGE2 release by tissue‐resident macrophages and initiate inflammatory painThe EMBO Journal, 2010
- P2X4 receptors in activated C8-B4 cells of cerebellar microglial originJournal of General Physiology, 2010
- Predominant Functional Expression of Kv1.3 by Activated Microglia of the Hippocampus after Status epilepticusPLOS ONE, 2009
- UDP acting at P2Y6 receptors is a mediator of microglial phagocytosisNature, 2007
- Involvement of P2X4and P2Y12receptors in ATP‐induced microglial chemotaxisGlia, 2007
- Altered Hippocampal Synaptic Potentiation in P2X4Knock-Out MiceJournal of Neuroscience, 2006