Villa, AnaSantiago, JorgeGarcía-Silva, SusanaRuiz-León, YolandaPascual, Angel2026-02-212026-02-212002-10Neurochem Int . 2002 Oct;41(4):261-9https://hdl.handle.net/20.500.12105/27255The beta-amyloid peptide, the major component of the senile plaques that characterize Alzheimer's disease, is generated from a set of alternatively spliced beta-amyloid precursor proteins (APPs), which are proteolytically cleaved by the action of a set of enzymes referred to generically as secretases. The major processing pathway involves the proteolytic cleavage of APP by alpha-secretase and results in the release of soluble non-amyloidogenic full-length amino terminal fragments (sAPP), which appear to be involved in neurotrophic events. A reduced production of these neuroprotective sAPP would contribute, together with deposition of the beta-amyloid peptide, to the neurodegenerative processes that lead to the cellular death in Alzheimer's disease. In the present work, we describe a dramatic reduction of sAPP content in medium conditioned by neuronal cells grown under low-serum conditions, when compared with the levels released in the presence of 10% serum. The inhibitory effect on sAPP release appears to be quite specific since that reduction occurs without major changes in cell proliferation, expression of APP-mRNA or intracellular APP levels. Under low-serum conditions, cells showed a more differentiated morphology and no apoptotic signs were observed. Since the alpha-secretase has been described as a membrane anchored protein, our results suggest that the serum contains an essential factor(s) involved in the alpha-secretase activity.engVoRhttp://creativecommons.org/licenses/by-nc-nd/4.0/serum concentrationsAPP releaseamyloid precursor protein (APP)neuroblastoma cellsAttribution-NonCommercial-NoDerivatives 4.0 International12106777414261-269Neurochem Intmetadata only access