Profiling of Aggregated Amyloid β42-induced Proteomic Alterations in KOLF2.1J Induced Pluripotent Stem Cell-derived...

Amyloid β (Aβ) plaques are a hallmark of Alzheimer's disease (AD). A human cellular neuronal model that recaptures Aβ-induced pathology is critical for advancing AD research. However, comprehensive proteomic profiling of Aβ-induced cellular model remains elusive. In this study, we investigated the proteomic changes in induced pluripotent stem cell (iPSC)-derived neurons (iNs) exposed to synthetic Aβ (1-42) peptides (Aβ42A) to improve our understanding of the cellular responses of Aβ aggregates and to establish a human-related platform for AD research. Aβ42A formed extracellular aggregates around neuronal soma and neurites, impaired neurite outgrowth, and induced the expression of multiple AD-associated genes, such as APOE, BACE1, ADAM10. To define the molecular landscape of Aβ-induced neuronal dysfunction, we performed proteomic analyses of whole-cell lysates as well as soma- and neurite-enriched fractions. Proteomic profiling revealed extensive gene alterations in pathways associated with synaptic function, neuronal maintenance, and AD pathogenesis, such as the upregulation of APOE. Importantly, the Aβ42A-iNs system recapitulated molecular signatures observed in AD brain tissue and cerebrospinal fluid. Representative protein changes, including APOE upregulation and its colocalization with Aβ aggregates, were further validated in postmortem human AD brain tissue. Together, these findings manifest that the Aβ42A-iNs system reproduces multiple cellular and molecular features of AD and exhibits strongly consensus with clinical observations. It provides a valuable platform for investigating Aβ-driven neurodegeneration and for the discovery of therapeutic targets for AD.