Purinergic receptors on microglial cells: functional expression in acute brain slices and modulation of microglial activation in vitro.
Microglial cells are the pathologic sensors in the brain. ATP released from damaged cells is a candidate for signalling neural injury to microglia. Moreover, ATP is an extracellular messenger for propagating astrocyte activity in the form of Ca2+ waves. To test for the functional expression of purinoreceptors in microglial cells we employed the patch-clamp technique in acute slices of adult mouse brain. ATP triggered a nonselective cationic and a K+ current. Pharmacological screening with purinergic ligands indicated the presence of P2Y1 and P2Y2/4 receptors linked to the activation of a K+ current and P2X receptors, including P2X7, linked to the activation of a nonselective cationic current. These findings suggest that microglial cells in situ express different purinergic receptors with distinct sensitivity and functional coupling. To test for the involvement of purinoreceptors in microglial activation, we stimulated cultured microglial cells with lipopolysaccharide and measured the release of tumour necrosis factor alpha, interleukin-6, interleukin-12 and macrophage inflammatory protein 1alpha, induction of K+ outward currents and nitric oxide release. All these parameters were reduced in the presence of purinergic ligands, indicating that purinergic receptor activation attenuated indicators of microglial activation.
Boucsein
Clemens
C
Max Delbrück Center for Molecular Medicine, Cellular Neuroscience, Robert-Rössle-Strasse10, D-13092, Berlin, Germany.
Zacharias
Robert
R
Färber
Katrin
K
Pavlovic
Sanja
S
Hanisch
Uwe-Karsten
UK
Kettenmann
Helmut
H
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D019830:Adenosine-5'-(N-ethylcarboxamide) / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018118:Chloride Channels / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology; D008274:Magnesium / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000502:physiology*; D009431:Neural Conduction / Q000187:drug effects; D009569:Nitric Oxide / Q000378:metabolism; D018408:Patch-Clamp Techniques / Q000379:methods; D015221:Potassium Channels / Q000187:drug effects; D011983:Receptors, Purinergic / Q000145:classification / Q000235:genetics / Q000502:physiology*; D013997:Time Factors; D014530:Uridine Diphosphate / Q000494:pharmacology; D014544:Uridine Triphosphate / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D018118:Chloride Channels; D008070:Lipopolysaccharides; D015221:Potassium Channels; D011983:Receptors, Purinergic; D014665:Vasodilator Agents; D009569:Nitric Oxide; D019830:Adenosine-5'-(N-ethylcarboxamide); C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D014530:Uridine Diphosphate; D000255:Adenosine Triphosphate; D008274:Magnesium; D002118:Calcium; D014544:Uridine Triphosphate