The First Generation of iPSC Line from a Korean Alzheimer's Disease Patient Carrying APP-V715M Mutation Exhibits a Distinct Mitochondrial Dysfunction

ABSTRACT

Alzheimer's Disease (AD) is a progressive neurodegenerative disease, which is pathologically defined by the accumulation of amyloid plaques and hyper-phosphorylated tau aggregates in the brain. Mitochondrial dysfunction is also a prominent feature in AD, and the extracellular Aβ and phosphorylated tau result in the impaired mitochondrial dynamics. In this study, we generated an induced pluripotent stem cell (iPSC) line from an AD patient with amyloid precursor protein (APP) mutation (Val715Met; APP-V715M) for the first time. We demonstrated that both extracellular and intracellular levels of Aβ were dramatically increased in the APP-V715M iPSC-derived neurons. Furthermore, the APP-V715M iPSC-derived neurons exhibited high expression levels of phosphorylated tau (AT8), which was also detected in the soma and neurites by immunocytochemistry. We next investigated mitochondrial dynamics in the iPSC-derived neurons using Mito-tracker, which showed a significant decrease of anterograde and retrograde velocity in the APP-V715M iPSC-derived neurons. We also found that as the Aβ and tau pathology accumulates, fusion-related protein Mfn1 was decreased, whereas fission-related protein DRP1 was increased in the APP-V715M iPSC-derived neurons, compared with the control group. Taken together, we established the first iPSC line derived from an AD patient carrying APP-V715M mutation and showed that this iPSC-derived neurons exhibited typical AD pathological features, including a distinct mitochondrial dysfunction.