Upregulation of insulin-like growth factor binding protein 3 in astrocytes of transgenic mice that express Borna disease virus phosphoprotein.

In a previous study, we demonstrated that transgenic mice that express Borna disease virus (BDV) phosphoprotein (P) in astrocytes show striking neurobehavioral abnormalities resembling those in BDV-infected animals. To understand the molecular disturbances induced by the expression of P in astrocytes, we performed microarray analysis with cultured astroglial cells transiently expressing P. We showed that expression of insulin-like growth factor binding protein 3 mRNA increases not only in P-expressing cultured cells but also in astrocytes from the cerebella of P transgenic mice (P-Tg). Furthermore, we demonstrated that insulin-like growth factor signaling is disturbed in the P-Tg cerebellum, a factor that might be involved in the increased vulnerability of Purkinje cell neurons in the brain.