Abstract
Microglia is activated by brain injury. They migrate in response to ATP and although adenosine alone has no effect on wild type microglial migration, we show that inhibition of adenosine receptors impedes ATP triggered migration. CD39 is the dominant cellular ectonucleotidase that degrades nucleotides to nucleosides, including adenosine. Importantly, ATP fails to stimulate P2 receptor mediated migration in cd39(-/-) microglia. However, the effects of ATP on migration in cd39(-/-) microglia can be restored by co-stimulation with adenosine or by addition of a soluble ectonucleotidase. We also tested the impact of cd39-deletion in a model of ischemia, in an entorhinal cortex lesion and in the facial nucleus after facial nerve lesion. The accumulation of microglia at the pathological sites was markedly decreased in cd39(-/-) animals. We conclude that the co-stimulation of purinergic and adenosine receptors is a requirement for microglial migration and that the expression of cd39 controls the ATP/adenosine balance.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenine Nucleotides / pharmacology
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Animals
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Animals, Newborn
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Antigens, CD / physiology*
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Apyrase / deficiency
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Apyrase / pharmacology
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Apyrase / physiology*
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Brain Ischemia / metabolism
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Brain Ischemia / pathology
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Cell Movement / drug effects
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Cell Movement / genetics*
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Cells, Cultured
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Cytokines / pharmacology
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Disease Models, Animal
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Dose-Response Relationship, Drug
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Drug Interactions
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Entorhinal Cortex / pathology
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Facial Nerve Diseases / metabolism
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Facial Nerve Diseases / pathology
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Facial Nerve Diseases / physiopathology
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Membrane Potentials / drug effects
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Membrane Potentials / physiology
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Mice
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Mice, Inbred C57BL
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Mice, Knockout
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Microglia / pathology
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Microglia / physiology*
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Microglia / ultrastructure
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Patch-Clamp Techniques / methods
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Receptors, Purinergic P1 / deficiency
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Receptors, Purinergic P2 / physiology*
Substances
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Adenine Nucleotides
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Antigens, CD
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Cytokines
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Receptors, Purinergic P1
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Receptors, Purinergic P2
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Apyrase
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CD39 antigen