Related Experiment Video
Updated: Apr 1, 2026

High-Density Lipoprotein-Specific Phospholipid Efflux Assay
Published on: September 30, 2025
Disrupted lipid homeostasis as a pathogenic mechanism in ABCA7-associated Alzheimer's disease risk
Younji Nam1, Brooke A DeRosa1, Aura M Ramirez1
1John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA.
Introduction:
ABCA7 (ATP binding cassette subfamily A member 7) encodes a lipid transporter associated with increasing risk for Alzheimer's disease (AD). A 44-base pair deletion in ABCA7 (rs142076058; p.Arg578Alafs) is a strong risk factor in individuals of African ancestry (AA). However, the biological consequences of this deletion are poorly understood.
Methods:
We expressed the truncated ABCA7 protein in HEK and HepG2 cells to assess cellular localization and impact on lipid metabolism, respectively. Additionally, induced pluripotent stem cell (iPSC)-derived neurons carrying the deletion were functionally assessed compared to isogenic controls.
Results:
Truncated ABCA7 localized to endoplasmic reticulum and plasma membranes similarly to the wild type in HEK cells but induced significant lipid droplet accumulation in HepG2 cells and iPSC-derived neurons while reducing mitochondrial membrane potential in iPSC-derived neurons.
Discussion:
These findings show that the AA-specific ABCA7 deletion disrupts lipid and mitochondrial homeostasis, supporting a mechanistic link between the ABCA7 deletion and increased AD risk.
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