Cellular consequences of the expression of Alzheimer's disease-causing presenilin 1 mutations in human neuroblastoma (SH-SY5Y) cells.
Mutations in the presenilin 1 (PS1) gene lead to early-onset Alzheimer's disease with the S170F mutation causing the earliest reported age of onset. Expression of this, and other PS1 mutations, in SH-SY5Y cells resulted in significant loss of cellular viability compared to control cells. Basal Ca2+ concentrations in PS1 mutants were never lower than controls and prolonged incubation in Ca2+ -free solutions did not deplete Ca2+ stores, demonstrating there was no difference in Ca2+ leak from endoplasmic reticulum (ER) stores in PS1 mutants. Peak muscarine-evoked rises of [Ca2+]i were variable, but the integrals were not significantly different, suggesting, while kinetics of Ca2+ store release might be affected in PS1 mutants, store size was similar. However, when Ca2+ -ATPase activity was irreversibly inhibited with thapsigargin, the S170F and ΔE9 cells showed larger capacitative calcium entry indicating a direct effect on Ca2+ influx pathways. There was no significant effect of any of the mutations on mitochondrial respiration. Amyloid β(Aβ(1-40)) secretion was reduced, and Aβ(1-42) secretion increased in the S170F cells resulting in a very large increase in the Aβ42/40 ratio. This, rather than any potential disruption of ER Ca2+ stores, is likely to explain the extreme pathology of this mutant.
Division of Cardiovascular and Neuronal Remodelling, Leeds Institute of Genetics, Health & Therapeutics, University of Leeds, Leeds, UK. j.p.boyle@leeds.ac.uk
John P
JP
Boyle
Nishani T
NT
Hettiarachchi
Jenny A
JA
Wilkinson
Hugh A
HA
Pearson
Jason L
JL
Scragg
Corinne
C
Lendon
Moza M
MM
Al-Owais
Cindy B
CB
Kim
David M
DM
Myers
Philip
P
Warburton
Chris
C
Peers
D016229:Amyloid beta-Peptides / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D053764:Presenilin-1 / Q000235:genetics* / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D053764:Presenilin-1; D002118:Calcium