[Roles of cyclooxygenase 2/2', 3'-cyclic nucleotide3' phosphohydrolase in the oligodendrocyte apoptosis in heroin-induced spongiform leucoencephalopathy].

ABSTRACT

OBJECTIVE: To investigate the regulation of cyclooxygenase (Cox)-2/2', 3'-cyclic nucleotide3' phosphohydrolase (CNPase) on the oligodendrocyte apoptosis in the pathogenesis of the heroin-induced spongiform leucoencephalopathy (HSLE). METHODS: Samples of frontal lobe, cerebellum, and corpus callosum were obtained from the brains during autopsy of 4 HSLE patients and 5 patients who died of diseases other than cerebral diseases (controls) and underwent light microscopy and electron microscopy. Immunocytochemistry was carried out to detect the expression of myelin basic protein (MBP), caspase-3, COX-2, and CNPase protein. Apoptosis was examined by TUNEL staining. RESULTS: Widespread demyelination was seen in the white matter of the frontal lobe, cerebellum, and corpus callosum of the HSLE cases, most severely in cerebellum. In he HSLE group, the levels of caspase-3 and COX-2 expression were significantly higher, and the level of CNPase was significantly lower than those of the control group (all P < 0.05). CONCLUSION: Widespread demyelination in the white matter is a prevailing pathological change of HSLE. Oligodendrocyte apoptosis is one of the causes of HSLE. The upregulation of COX-2 and downregulation of CNPase may contribute to the pathogenesis.