Glial conditioned medium alters the expression of amyloid precursor protein in SH-SY5Y neuroblastoma cells

The effect of conditioned medium from astroglia or microglia cultures on the mRNA expression of amyloid precursor protein (APP) in SH-SY5Y human neuroblastoma cells was examined. When incubated with conditioned medium of glial cells, SH-SY5Y cells expressed a larger amount of APP mRNA than the control cells. Reverse transcription followed by the polymerase chain reaction showed marked induction of expression of APP isoforms containing a Kunitz-type protease inhibitor domain. Our results suggest that glial cells may contribute to the regulation of expression of APP in neurons.