Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2009-3-19
pubmed:abstractText
Microglia in the dorsal horn of the spinal cord are increasingly recognized as being crucial in the pathogenesis of pain hypersensitivity after injury to a peripheral nerve. It is known that P2X4 purinoceptors (P2X4Rs) cause the release of brain-derived neurotrophic factor (BDNF) from microglia, which is necessary for maintaining pain hypersensitivity after nerve injury. However, there is a critical gap in understanding how activation of microglial P2X4Rs leads to the release of BDNF. Here, we show that stimulating P2X4Rs with ATP evokes a biphasic release of BDNF from microglia: an early phase occurs within 5 min, whereas a late phase peaks 60 min after ATP stimulation. Concomitant with the late phase of release is an increased level of BDNF within the microglia. Both phases of BDNF release and the accumulation within the microglia are dependent on extracellular Ca(2+). The late phase of BDNF release and accumulation, but not the early phase of release, are suppressed by inhibiting transcription and translation, indicating that activation of P2X4R causes an initial release of a pre-existing pool of BDNF followed by an increase in de novo synthesis of BDNF. The release of BDNF is abolished by inhibiting SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-mediated exocytosis. Furthermore, we find that the P2X4R-evoked release and synthesis of BDNF are dependent on activation of p38-mitogen-activated protein kinase (MAPK). Together, our findings provide a unifying mechanism for pain hypersensitivity after peripheral nerve injury through P2X4R-evoked increase in Ca(2+) and activation of p38-MAPK leading to the synthesis and exocytotic release of BDNF from microglia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
18
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3518-28
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
P2X4-receptor-mediated synthesis and release of brain-derived neurotrophic factor in microglia is dependent on calcium and p38-mitogen-activated protein kinase activation.
pubmed:affiliation
Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't