Immunohistochemical localization of phosphoinositide 3-kinase in brains with multiple system atrophy

Oligodendrocytes have been shown to display some morphological characterist ics of apoptosis in MSA. The accumulated evidence shows that phosphoinositi de 3-kinase (P13K) is closely associated with the regulation of apoptosis. Thus, we examined immunohistochemically P13K in the cerebellum and pons fro m autopsy samples with MSA. In control tissues, P13K was immunostained in s ome neurons and a few oligodendrocytes. In MSA samples, the larger number o f oligodendrocytes was observed in the pons and cerebellum. Furthermore, so me neurons were strongly immunolabeled in MSA samples. The recent study has shown that P13K phosphorylates PKB/Akt which phosphorylates BAD resulting in the cessation of apoptotic process. The present results suggest that P13 K is upregulated in oligodendrocytes and some neurons in MSA, possibly in r esponse to the apoptotic signals to these cells.