Characterization of neural cell types expressing peroxiredoxins in mouse brain

The differential expression patterns of antioxidant enzymes observed in the brains of patients with neurodegenerative diseases suggest an important role for reactive oxygen species and antioxidant enzymes in neurodegeneration. The six mammalian peroxiredoxins (Prxs) comprise a novel family of anti-oxidative proteins that are widely distributed in most tissues, but few studies of Prx in brain tissue have been reported. The specific histology of the neural cell types in which Prxs are expressed is an important issue related to biological function and defense against oxidative stress in the brain. This study analyzed mouse brain neural cell types expressing Prx isoforms using single- or double-label immunohistochemical techniques. In neurons, immunoreactivity for Prx II-V was observed in the cytoplasm. In particular, Prx II was found in the habenular nuclei, and Prx III and V were found in the stratum lucidum of the hippocampus. Astrocytes and microglia were immunoreactive only for Prx VI and Prx I, respectively. Prx I and IV immunoreactivity was apparent in oligodendrocytes, where it was principally localized in the nuclei. The observed distribution of Prx isoforms in the mammalian brain may be indicative of their specific roles in their preferred neural cell types and subcellular locales. The results of this study will help in unraveling the physiological and pathophysiological roles of the different Prx isoforms in neural function.