Abstract
1. The amyloid precursor protein (APP) is widely distributed among eukaryotic cells, however, its precise role in cellular functioning is not fully clarified. APP is glycoprotein membrane constituent and it may facilitate membrane associated functions. 2. The aim of the present study was to examine the possibility that APP may play a role in mediating cellular trophic responses. The methods made use of an antisense oligonucleotide that was prepared to the 5' terminus of APP and shown specifically to reduce the level of APP isoforms. 3. In sequential mixing experiments it was observed that the APP antisense oligonucleotide did not significantly modify the trophic response of PC12 cells pretreated with nerve growth factor (NGF). However, pretreatment of cells with the antisense oligonucleotide diminished NGF-induced increases in cellular size and neurite length. 4. These observations suggest that APP may play a role in modulating the trophic response. The combined use of APP antisense oligonucleotides and neurotrophic agents may find clinical utility in the treatment of Alzheimer-type dementia since it is known that NGF normally causes increases in APP levels.