Pluripotent Cells Expressing APOE4 Exhibit a Pronounced Pro-Apoptotic Phenotype Accompanied by Markers of Hyperinflammation and a Blunted NF-κB Response

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that poses an increasing burden on society. It is characterized by the presence of neurofibrillary tangles (NFTs) and amyloid-beta (Aβ) plaques. AD is a multifactorial disease, with one of the strongest genetic risk factors being the APOE4 allele. In this study, we investigated the impact of APOE4 on NF-κB signaling in induced pluripotent stem (iPS) cells. Our results indicate that APOE4 may influence the subcellular localization of the pluripotency marker OCT4, showing a predominantly nuclear localization in APOE4 cells, whereas it appears cytoplasmic in APOE3 cells. Additionally, NF-κB activation via its canonical subunits is blunted in APOE4 cells. Interestingly, APOE4 cells still exhibit increased transcription of key hyperinflammatory markers CCL2, CXCL10 and COX2, which are known NF-κB target genes, and exhibit a significantly higher rate of apoptosis compared to APOE3 cells—independent of TNF-α stimulation. Moreover, an elevated incidence of DNA double-strand breaks was observed in APOE4 cells. However, the precise molecular mechanisms by which APOE4 suppresses NF-κB activation while simultaneously promoting inflammation and apoptosis remain unclear. Further research is required to elucidate these underlying pathways.