Immunolocalization of iron regulatory protein expression in the murine central nervous system

We examined the expression of the iron regulatory proteins 1 and 2 (IRP1 an d IRP2) in the brains of adult (4-6 months) CBA/J mice. Anti-IRP1 immunorea ctivity was localized to cell bodies, including putative neurons and oligod endrocytes. In contrast, anti-IRP2 staining was prevalent throughout the ne uropil of regions of the brain consistent with the central autonomic networ k (CAN) and messy fibers emanating from hippocampal dentate granule cells. Essentially no staining for IRP2 was observed in the cerebellum in contrast to strong IRP1 immunoreactivity in Purkinje cells. Notably, cells within o ne vestibular nucleus exhibited staining by both IRP1 and IRP2. Our results suggest distinct roles for IRP1 and IRP2 in the regulation of iron homeost asis in the mammalian nervous system where IRP1 may provide a maintenance f unction in contrast to IRP2 that could participate in modulating proper CAN functions, including cardiopulmonary, gustatory as well as fine motor cont rol.