Forskning

September 4, 2018

Roasted coffee reduces β-amyloid production by increasing proteasomal β-Secretase degradation in human neuroblastoma SH-SY5Y cells

K Fukuyama et al, 2018. Roasted coffee reduces β-amyloid production by increasing proteasomal β-Secretase degradation in human neuroblastoma SH-SY5Y cells, Mol Nutr Food Research, published online.

ABSTRACT:

Scope: Epidemiological studies have shown that coffee consumption may be associated with a lower risk of developing several neurological disorders, including Alzheimer’s disease (AD). Caffeine is a prominent candidate component underlying the preventive effects of coffee; however, the contribution of other constituents is unclear. To clarify this issue, we analyzed the effect of roasting coffee beans on β‐secretase (BACE1) expression in human neuroblastoma SH‐SY5Y cells.

Methods and results: Coffee (2%) reduced Aβ accumulation in culture medium to 80% of control levels after 24 h. Accordingly, BACE1 expression was decreased to 70% of control levels at 12 h. Experiments using cycloheximide and MG132, a proteasome inhibitor, revealed that coffee enhanced BACE1 degradation through activation of proteasomal activity. Furthermore, coffee activates cAMP‐dependent protein kinase, and consequently, phosphorylation of a serine residue of proteasome 26S subunit, non‐ATPase 11 (PSMD11). Pyrocatechol, a strong antioxidant known as catechol or 1,2‐dihydroxybenzene, produced from chlorogenic acid during roasting, also reduced BACE1 expression by activation of proteasomal activity. Furthermore, pyrocatechol reduced Aβ production in SH‐SY5Y cells.

Conclusion: Our data suggest that the roasting process may be crucial for the protective effects of coffee consumption in AD.