Upregulation of osteopontin expression in XXXX spinal cord microglia after traumatic injury.

@entity63 @entity39 @entity2850 @entity1566 @entity35 @entity385
Osteopontin is a noncollagenous extracellular matrix protein that is expressed in various tissues. Recent studies have shown the upregulation of osteopontin expression in the @entity63 cortex after @entity385 . We demonstrate here the upregulation of osteopontin expression in the spinal cord after @entity2850 . @entity35 were used in a compression model of @entity1566 (30-g load for 5 min). Northern blot analysis showed that osteopontin mRNA expression levels reached a peak 3 days after injury (sevenfold; p < 0.05). In situ hybridization demonstrated osteopontin mRNA expression in @entity39 areas from 24 h, peaking 3 days after injury. Immunohistochemistry detected osteopontin protein immunoreactivity from 12 h, peaking at 3 days. The peak time and distribution of osteopontin protein expression were coincident with those of osteopontin mRNA expression. Osteopontin expression in our model preceded that shown in the previously reported @entity385 models. Osteopontin protein was found in the cytoplasm at 3 days and secreted into the extracellular matrix at 7 days. Triple immunolabeling showed that osteopontin was localized in activated microglia surrounded by astrocytes.
