Secretory processing of amyloid precursor protein is inhibited by increase in cellular cholesterol content
Articolo
Data di Pubblicazione:
1997
Citazione:
Secretory processing of amyloid precursor protein is inhibited by increase in cellular cholesterol content / M. Racchi, R. Baetta, N. Salvietti, P. Ianna, G. Franceschini, R. Paoletti, R. Fumagalli, S. Govoni, M. Trabucchi, M. Soma. - In: BIOCHEMICAL JOURNAL. - ISSN 0264-6021. - 322:3(1997), pp. 893-898.
Abstract:
Plasma-membrane composition plays a crucial role in most of the cellular functions that depend on membrane processes. In virtually all cell types the proteolytic processing of Alzheimer amyloid precursor protein (APP) to generate soluble APP (sAPP) is believed to occur at the plasma membrane or in its immediate proximity. Alteration of this metabolic pathway has been linked to the pathogenesis of Alzheimer's disease. We analysed the effect of membrane cholesterol enrichment on APP metabolism. Incubation of COS cells with increasing concentrations of non-esterified cholesterol carried by rabbit β-very low-density lipoprotein caused a dose-dependent inhibition of sAPP release: 70% inhibition with 10 μg/ml non-esterified cholesterol. A less pronounced inhibitory effect was observed on treatment with human low-density lipoprotein. Inhibition of sAPP release was independent of receptor-mediated lipoprotein metabolism since simultaneous treatment with chloroquine did not modify the effect of lipoprotein treatment. In addition, treatment with cholesterol dissolved in either ethanol or methyl-β-cyclodextrin elicited the same effect. Excess non-esterified cholesterol did not cause cell toxicity. Cell cholesterol mass inversely correlated with sAPP release. Progesterone, which inhibits shuttling of nonesterified cholesterol between the plasma membrane and intracellular pools, had no effect on the inhibition of sAPP release from cholesterol-loaded cells, providing indirect evidence that cholesterol may act at the plasma membrane.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
M. Racchi, R. Baetta, N. Salvietti, P. Ianna, G. Franceschini, R. Paoletti, R. Fumagalli, S. Govoni, M. Trabucchi, M. Soma
Link alla scheda completa: