Neuronal expression of myeloperoxidase is increased in Alzheimer's disease
Article first published online: 2 JUL 2004
Journal of Neurochemistry
Volume 90, Issue 3, pages 724–733, August 2004
How to Cite
Green, P. S., Mendez, A. J., Jacob, J. S., Crowley, J. R., Growdon, W., Hyman, B. T. and Heinecke, J. W. (2004), Neuronal expression of myeloperoxidase is increased in Alzheimer's disease. Journal of Neurochemistry, 90: 724–733. doi: 10.1111/j.1471-4159.2004.02527.x
- Issue published online: 2 JUL 2004
- Article first published online: 2 JUL 2004
- Received January 14, 2004; revised manuscript received March 19, 2004; accepted March 23, 2004.
- Alzheimer's disease;
- oxidative stress;
Myeloperoxidase, a heme protein expressed by professional phagocytic cells, generates an array of oxidants which are proposed to contribute to tissue damage during inflammation. We now report that enzymatically active myeloperoxidase and its characteristic amino acid oxidation products are present in human brain. Further, expression of myeloperoxidase is increased in brain tissue showing Alzheimer's neuropathology. Consistent with expression in phagocytic cells, myeloperoxidase immunoreactivity was present in some activated microglia in Alzheimer brains. However, the majority of immunoreactive material in brain localized with amyloid plaques and, surprisingly, neurons including granule and pyramidal neurons of the hippocampus. Confirming neuronal localization of the enzyme, several neuronal cell lines as well as primary neuronal cultures expressed myeloperoxidase protein. Myeloperoxidase mRNA was also detected in neuronal cell lines. These results reveal the unexpected presence of myeloperoxidase in neurons. The increase in neuronal myeloperoxidase expression we observed in Alzheimer disease brains raises the possibility that the enzyme contributes to the oxidative stress implicated in the pathogenesis of the neurodegenerative disorder.