We have used single- and double-labeling immunfluorescence and reverse transcription-polymerase chain reaction (RT-PCR) methods to examine expression of P2X receptor subtypes on microglial cells of brain in late embryonic and postnatal rat, in the N9 microglial cell line and primary cultured microglial cells. P2X1, P2X4, and P2X7 receptors were shown on microglial cells from late embryonic day ...

Rapid modulation of the surface number of certain ionotropic receptors is achieved by altering the relative rates of insertion and internalization. These receptors are internalized by a clathrin-mediated pathway; however, a motif that is necessary for endocytosis of ionotropic receptors has not yet been identified. Here, we identified a motif that is required for constitutive and agonist-regula...

P2X receptors, activated by extracellular ATP, may be important in regulating cardiac function. The objective of the present study was to characterize the electrophysiologic actions of P2X4 receptors in cardiac myocytes and to determine whether they are involved in mediating the effect of extracellular ATP. Membrane currents under voltage clamp were determined in myocytes from both wild-type (W...

Hypoxia and increased extracellular nucleotides are frequently coincident in the brainstem. Extracellular nucleotides are potent modulators of microglial inflammatory gene expression via P2X purinergic receptor activation. Although hypoxia is also known to modulate inflammatory gene expression, little is known about how hypoxia or P2X receptor activation alone affect inflammatory molecule produ...

We isolated a cDNA from human brain encoding a purinergic receptor that shows a high degree of homology to the rat P2X4 receptor (87% identity). By fluorescence in situ hybridization, the human P2X4 gene has been mapped to region q24.32 of chromosome 12. Tissue distribution analysis of human P2X4 transcripts demonstrates a broad expression pattern in that the mRNA was detected not only in brain...

The P2X4 receptor is involved in endothelium-dependent changes in large arterial tone in response to shear stress and is, therefore, potentially relevant to arterial compliance and pulse pressure. Four identified nonsynonymous polymorphisms in P2RX4 were reproduced in recombinantly expressed human P2X4. Electrophysiological studies showed that one of these, the Tyr315>Cys mutation (rs28360472),...

We investigated the properties and regulation of P2X receptors in immortalized C8-B4 cells of cerebellar microglial origin. Resting C8-B4 cells expressed virtually no functional P2X receptors, but largely increased functional expression of P2X4 receptors within 2-6 h of entering the activated state. Using real-time polymerase chain reaction, we found that P2X4 transcripts were increased during ...

We recently reported that degenerating motor neurons of superoxide dismutase mutant 1 (SOD1) rodents exhibit immunoreactivity to P2X4 antibodies. Neurons with strong P2X4-like immunoreactivity (P2X4-LIR) do not show an apoptotic phenotype and are often associated with microglial cells that display neuronophagic activity. Western blot analysis showed that P2X4 antibodies recognize not only the P...

P2X4 purinergic receptors are calcium-permeable, ATP-activated ion channels. In the CA1 area of the hippocampus, they are located at the subsynaptic membrane somewhat peripherally to AMPA receptors. The possible role of P2X4 receptors has been difficult to elucidate because of the lack of selective antagonists. Here we report the generation of a P2X4 receptor knock-out mouse and show that long-...

Differential Modulation by Copper and Zinc of P2X2 and P2X4 Receptor Function. The modulation by Cu2+ and Zn2+ of P2X2 and P2X4 receptors expressed in Xenopus oocytes was studied with the two-electrode, voltage-clamp technique. In oocytes expressing P2X2 receptors, both Cu2+ and Zn2+, in the concentration range 1-130 microM, reversibly potentiated current activated by submaximal concentrations ...