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Pannexons are membrane channels formed by pannexins and are permeable to ATP. They have been implicated in various physiological and pathophysiological processes. Innexins, the invertebrate homologues of the pannexins, form innexons. Nerve injury induces calcium waves in glial cells, releasing ATP through glial pannexon/innexon channels. The ATP then activates microglia. More slowly, injury releases arachidonic acid (ArA). The present experiments show that ArA itself reduced the macroscopic membrane currents of innexin- and of pannexin-injected oocytes; ArA also blocked K(+) -induced release of ATP. In leeches, whose large glial cells have been favorable for studying control of microglia migration, ArA blocked glial dye-release and, evidently, ATP-release. A physiological consequence in the leech was block of microglial migration to nerve injuries. Exogenous ATP (100 µM) reversed the effect, for ATP causes activation and movement of microglia after nerve injury, but nitric oxide directs microglia to the lesion. It was not excluded that metabolites of ArA may also inhibit the channels. But for all these effects, ArA and its non-metabolizable analog eicosatetraynoic acid (ETYA) were indistinguishable. Therefore, ArA itself is an endogenous regulator of pannexons and innexons. ArA thus blocks release of ATP from glia after nerve injury and thereby, at least in leeches, stops microglia at lesions.
Aguzzi,
Microglia: scapegoat, saboteur, or something else?
2013, Pubmed
Aguzzi,
Microglia: scapegoat, saboteur, or something else?
2013,
Pubmed Bao,
Pannexin membrane channels are mechanosensitive conduits for ATP.
2004,
Pubmed
,
Xenbase Bao,
Innexins form two types of channels.
2007,
Pubmed
,
Xenbase Bianco,
Astrocyte-derived ATP induces vesicle shedding and IL-1 beta release from microglia.
2005,
Pubmed Boger,
Arachidonic acid amide inhibitors of gap junction cell-cell communication.
1999,
Pubmed Börjesson,
An electrostatic potassium channel opener targeting the final voltage sensor transition.
2011,
Pubmed
,
Xenbase Chen,
Nitric oxide influences injury-induced microglial migration and accumulation in the leech CNS.
2000,
Pubmed COGGESHALL,
THE FINE STRUCTURE OF THE CENTRAL NERVOUS SYSTEM OF THE LEECH, HIRUDO MEDICINALIS.
1964,
Pubmed Dahl,
Pannexin: to gap or not to gap, is that a question?
2006,
Pubmed Davalos,
ATP mediates rapid microglial response to local brain injury in vivo.
2005,
Pubmed De Petrocellis,
Aquatic invertebrates open up new perspectives in eicosanoid research: biosynthesis and bioactivity.
1994,
Pubmed Duan,
Repair and regeneration of functional synaptic connections: cellular and molecular interactions in the leech.
2005,
Pubmed Duan,
ATP and NO dually control migration of microglia to nerve lesions.
2009,
Pubmed Dykes,
Molecular characterization and embryonic expression of innexins in the leech Hirudo medicinalis.
2006,
Pubmed Elliot,
Long-term survival of glial segments during nerve regeneration in the leech.
1981,
Pubmed Fang,
Arachidonic acid modulates Na+ currents by non-metabolic and metabolic pathways in rat cerebellar granule cells.
2011,
Pubmed Firme,
Ectopic expression of select innexins in individual central neurons couples them to pre-existing neuronal or glial networks that express the same innexin.
2012,
Pubmed Fluri,
Effects of arachidonic acid on the gap junctions of neonatal rat heart cells.
1990,
Pubmed Gabryel,
Activation of cPLA2 and sPLA2 in astrocytes exposed to simulated ischemia in vitro.
2007,
Pubmed Giaume,
Arachidonic acid closes gap junction channels in rat lacrimal glands.
1989,
Pubmed Gronert,
Lipid autacoids in inflammation and injury responses: a matter of privilege.
2008,
Pubmed Guthrie,
ATP released from astrocytes mediates glial calcium waves.
1999,
Pubmed Honda,
Extracellular ATP or ADP induce chemotaxis of cultured microglia through Gi/o-coupled P2Y receptors.
2001,
Pubmed Iglesias,
Pannexin 1: the molecular substrate of astrocyte "hemichannels".
2009,
Pubmed Inoue,
Microglial activation by purines and pyrimidines.
2002,
Pubmed Järving,
On the evolutionary origin of cyclooxygenase (COX) isozymes: characterization of marine invertebrate COX genes points to independent duplication events in vertebrate and invertebrate lineages.
2004,
Pubmed Jiang,
Stimulation of rat erythrocyte P2X7 receptor induces the release of epoxyeicosatrienoic acids.
2007,
Pubmed Kanneganti,
Pannexin-1-mediated recognition of bacterial molecules activates the cryopyrin inflammasome independent of Toll-like receptor signaling.
2007,
Pubmed Kuffler,
The physiology of neuroglial cells.
1966,
Pubmed KUFFLER,
GLIA IN THE LEECH CENTRAL NERVOUS SYSTEM: PHYSIOLOGICAL PROPERTIES AND NEURON-GLIA RELATIONSHIP.
1964,
Pubmed Kumar,
Nerve injury induces a rapid efflux of nitric oxide (NO) detected with a novel NO microsensor.
2001,
Pubmed Liu,
Oxygen-glucose deprivation induces ATP release via maxi-anion channels in astrocytes.
2008,
Pubmed López-Vales,
Phospholipase A2 superfamily members play divergent roles after spinal cord injury.
2011,
Pubmed MacVicar,
Non-junction functions of pannexin-1 channels.
2010,
Pubmed Maingret,
Mechano- or acid stimulation, two interactive modes of activation of the TREK-1 potassium channel.
1999,
Pubmed Martínez,
Arachidonic acid-induced dye uncoupling in rat cortical astrocytes is mediated by arachidonic acid byproducts.
1999,
Pubmed McGlade-McCulloh,
Individual microglia move rapidly and directly to nerve lesions in the leech central nervous system.
1989,
Pubmed Miller,
Rapid, simultaneous quantitation of mono and dioxygenated metabolites of arachidonic acid in human CSF and rat brain.
2009,
Pubmed Minghetti,
Cyclooxygenase-2 (COX-2) in inflammatory and degenerative brain diseases.
2004,
Pubmed Minghetti,
Microglia as effector cells in brain damage and repair: focus on prostanoids and nitric oxide.
1998,
Pubmed Miyachi,
Arachidonic acid blocks gap junctions between retinal horizontal cells.
1994,
Pubmed Monaghan,
The stretch-dependent potassium channel TREK-1 and its function in murine myometrium.
2011,
Pubmed Morgese,
Microglial movement to sites of nerve lesion in the leech CNS.
1983,
Pubmed Ngu,
Reduced axon sprouting after treatment that diminishes microglia accumulation at lesions in the leech CNS.
2007,
Pubmed Pelegrin,
P2X7 receptor differentially couples to distinct release pathways for IL-1beta in mouse macrophage.
2008,
Pubmed Phillis,
Cyclooxygenases, lipoxygenases, and epoxygenases in CNS: their role and involvement in neurological disorders.
2006,
Pubmed Qiu,
Two non-vesicular ATP release pathways in the mouse erythrocyte membrane.
2011,
Pubmed Qiu,
A permeant regulating its permeation pore: inhibition of pannexin 1 channels by ATP.
2009,
Pubmed
,
Xenbase Salter,
ATP causes release of intracellular Ca2+ via the phospholipase C beta/IP3 pathway in astrocytes from the dorsal spinal cord.
1995,
Pubmed Samuels,
Neuroglial ATP release through innexin channels controls microglial cell movement to a nerve injury.
2010,
Pubmed
,
Xenbase Scemes,
Astrocyte calcium waves: what they are and what they do.
2006,
Pubmed Schipke,
Astrocyte Ca2+ waves trigger responses in microglial cells in brain slices.
2002,
Pubmed Scuri,
Role for calcium signaling and arachidonic acid metabolites in the activity-dependent increase of AHP amplitude in leech T sensory neurons.
2005,
Pubmed Shafer,
Injury-induced expression of endothelial nitric oxide synthase by glial and microglial cells in the leech central nervous system within minutes after injury.
1998,
Pubmed Shuttleworth,
Arachidonic acid, ARC channels, and Orai proteins.
2009,
Pubmed Silverman,
The pannexin 1 channel activates the inflammasome in neurons and astrocytes.
2009,
Pubmed
,
Xenbase Sosinsky,
Pannexin channels are not gap junction hemichannels.
2011,
Pubmed Sun,
Phospholipase A2 in the central nervous system: implications for neurodegenerative diseases.
2004,
Pubmed Sun,
Phospholipase A2 in astrocytes: responses to oxidative stress, inflammation, and G protein-coupled receptor agonists.
2005,
Pubmed Verderio,
ATP mediates calcium signaling between astrocytes and microglial cells: modulation by IFN-gamma.
2001,
Pubmed von Bernhardi,
Repair of the central nervous system: lessons from lesions in leeches.
1995,
Pubmed Wang,
SCAM analysis of Panx1 suggests a peculiar pore structure.
2010,
Pubmed
,
Xenbase Watts,
Genetic dissection of polyunsaturated fatty acid synthesis in Caenorhabditis elegans.
2002,
Pubmed Westcott,
Eicosanoids in human ventricular cerebrospinal fluid following severe brain injury.
1987,
Pubmed Xu,
Activation of cytosolic phospholipase A2alpha through nitric oxide-induced S-nitrosylation. Involvement of inducible nitric-oxide synthase and cyclooxygenase-2.
2008,
Pubmed Yazdani,
Expression of a dominant negative mutant innexin in identified neurons and glial cells reveals selective interactions among gap junctional proteins.
2013,
Pubmed
