Cyclooxygenase-1 and-2 in brains of patients who died with sporadic Creutzfeldt-Jakob disease

Cyclooxygenases (COXs) mediate inflammation, immunomodulation, blood flow, apoptosis, and fever in various diseases of the brain. Whereas COX-2 is cytokine inducible, COX-1 is expressed by macrophages/microglial cells that accumulate in pathological foci. We analyzed the localization of COX-1 and COX-2 in postmortem cortex slices of eight patients who died with sporadic Creutzfeldt-Jakob disease (CJD) and four neuropathologically unaltered controls by immunohistochemical double-labeling, reverse transcriptase polymerase chain reaction (RT-PCR), and Western blotting experiments. In healthy brains, COX-1 was expressed by single macrophages / microglial cells and COX-2 by disseminated neurons. In patients with CJD, significantly (p = 0.0195) more COX-1-expressing macrophages/microglial cells were detected adjacent to neurons. COX-2 expression was predominantly observed in neurons, and their number was significantly higher (p < 0.0001) compared to controls. RT-PCR and Western blotting revealed more COX-1 and COX-2 mRNA and protein in one CJD patient than in one control patient. These data show that accumulation of COX-1-expressing macrophages/microglial cells and COX-2-expressing neurons might represent important regulatory mechanisms in the complex process of neuronal degeneration in CJD patients.