Expression of DJ-1 in the adult mouse CNS.

Recessively inherited mutations in DJ-1 have recently been linked to familial forms of parkinsonism. However, the regional and cellular expression of DJ-1 is largely unknown. In the present study, we mapped the distribution of DJ-1 transcript and protein by non-radioactive in situ hybridization and immunohistochemistry in adult mouse CNS. For immunohistochemical analysis, we raised a polyclonal antiserum against GST-mouse DJ-1 fusion protein. DJ-1 transcript and protein were strongly and homogenously expressed in all CNS regions. Colocalization experiments revealed expression in neurons of different neurotransmitter phenotypes and in all glial cell types, such as astrocytes, microglia and oligodendrocytes. DJ-1 protein was diffusely distributed throughout the cytoplasma of the soma and the proximal parts of the processes, while the nuclei were always spared. The high expression of DJ-1 in neuronal and glial cells, that is not confined to a single functional system or any anatomical area, supports the view of a basic physiological role in cell biology.