title: Osteopontin expression during early cerebral ischemia-reperfusion in rats: enhanced expression in the right cortex is suppressed by acetaminophen.
abstract: Osteopontin (OPN) is a pleiotropic protein implicated in various inflammatory responses including ischemia-reperfusion (I-R) injury. Two distinct forms of the protein have been identified: an extensively studied secreted form (sOPN) and a less-well-known intracellular form (iOPN). Studies have shown that increased OPN expression parallels the time course of macrophage infiltration into injured tissue, a late event in the development of cerebral infarcts. sOPN has been suggested to promote remodeling of the extracellular matrix in the brain; the function of iOPN may be to facilitate certain signal transduction processes. Here, we studied OPN expression in adult male Sprague-Dawley rats subjected to global forebrain I-R injury. We found iOPN in the cytoplasm of both cortices and the hippocampus, but unexpectedly only the right cortex exhibited a marked increase in the iOPN level after 45 min of reperfusion. Acetaminophen, a drug recently shown to decrease apoptotic incidence, caspase-9 activation, and mitochondrial dysfunction during global I-R, significantly inhibited the increase in iOPN protein in the right cortex, suggesting a role for iOPN in the response to I-R injury in the right cortex.
authors.affiliation: Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey, United States of America.
authors.forename: Sunanda S
authors.initials: SS
authors.lastname: Baliga
authors.forename: Gary F
authors.initials: GF
authors.lastname: Merrill
authors.forename: Mari L
authors.initials: ML
authors.lastname: Shinohara
authors.forename: David T
authors.initials: DT
authors.lastname: Denhardt
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D000818:Animals; D002545:Brain Ischemia / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D053495:Osteopontin / Q000032:analysis / Q000096:biosynthesis* / Q000187:drug effects*; D051381:Rats; D015427:Reperfusion Injury / Q000378:metabolism*
chemical_list: D053495:Osteopontin; D000082:Acetaminophen