Expression and cellular localization of cyclooxygenases and prostaglandin E synthases in the hemorrhagic brain

Background: although cyclooxygenases (cox) and prostaglandin e synthases (pges) have been implicated in ischemic stroke injury,little is known about their role in intracerebral hemorrhage (ich)-induced brain damage. this study examines the expression and cellular localization of cox-1,cox-2,microsomal pges-1 (mpges-1),mpges-2,and cytosolic pges (cpges) in mice that have undergone hemorrhagic brain injury.methods: ich was induced in c57bl/6 mice by intrastriatal injection of collagenase. expression and cellular localization of cox-1,cox-2,mpges-1,mpges-2,and cpges were examined by immunofluorescence staining.results: in the hemorrhagic brain,cox-1,mpges-2,and cpges were expressed constitutively in neurons; cox-1 was also constitutively expressed in microglia. the immunoreactivity of cox-2 was increased in neurons and astrocytes surrounding blood vessels at 5 h and then tended to decrease in neurons and increase in astrocytes at 1 day. at 3 days after ich,cox-2 was observed primarily in astrocytes but was absent in neurons. interestingly,the immunoreactivity of mpges-1 was increased in neurons in the ipsilateral cortex and astrocytes in the ipsilateral striatum at 1 day post-ich; the immunoreactivity of astrocytic mpges-1 further increased at 3 days.conclusion: our data suggest that microglial cox-1,neuronal cox-2,and astrocytic cox-2 and mpges-1 may work sequentially to affect ich outcomes. these findings have implications for efforts to develop anti-inflammatory strategies that target cox/pges pathways to reduce ich-induced secondary brain damage. © 2011 wu et al; licensee biomed central ltd.