Localization of cyclooxygenase-2 induced following traumatic spinal cord injury

Abstract

Objective: Up-regulation of cyclooxygenase-2 (COX-2), a key enzyme in the synthesis of prostaglandins (PGs), is postulated to be involved in pathological processes of acute spinal cord injury (SCI). In the present study, we sought to clarify temporal and spatial expression patterns of the COX-2 gene induced in the spinal cord after traumatic insults using a weight-drop technique.

Results: Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that COX-2 transcription in the spinal cord began to increase within 30 min, peaked at 3 h after injury. Western blotting analysis indicated that the deglycosylated COX-2 protein significantly increased 6 h after injury. Double-immunofluorescent staining analysis showed that COX-2 immunoreactivity was present only in endothelial cells of blood vessels, but not in neurons, astrocytes, monocytes, macrophages, or microglia 6 h after injury.

Conclusions: The results suggested that COX-2 gene induction seems not to require any new protein synthesis and that its expression in endothelial cells may be a component of an inflammatory process after traumatic SCI.