NEURONAL SECRETOME REMODELLING IN RESPONSE TO AGE-RELATED OXIDATIVE STRESS

Oxidative stress is a hallmark of aging, causing cumulative cellular damage that elevates susceptibility to neurodegenerative disorders. We investigated protein secretion patterns in SH-SY5Y human neuroblastoma cells subjected to mild oxidative conditions replicating age-associated environments. Cells were exposed to 150 µM hydrogen peroxide over 24 hours, and conditioned media were harvested for proteomic profiling and gene ontology (GO) analysis. Proteomic screening revealed overexpression of 4,101 proteins. Functional enrichment via g:Profiler demonstrated substantial GO term representation, refined to exclude cell cycle-associated processes given the postmitotic nature of differentiated neurons. Key enriched categories included Nucleoplasm, Cytosol and Membrane coat (cellular components); Protein binding, Molecular adaptor activity and Catalytic activity (molecular functions); and Regulation of primary metabolic process alongside Organelle organization (biological processes). Pathway analysis through Reactome unveiled predominant activation of gene regulatory mechanisms including Epigenetic regulation (HDAC1), Transcription (TBP), Mediator complex (MED1) and RNA processing (SF3B1), as well as intracellular transport systems encompassing ER and Golgi trafficking (SEC13), Endocytosis (RAB5A), Late endosomes and Lysosomes (RAB7A), Motors and scaffolds (KIF1A), and Membrane fusion (NSF). These findings demonstrate that mild oxidative stress elicits an extensive adaptive response characterized by upregulation of transcriptional regulators and vesicular transport components, indicating active neuronal attempts to restore homeostasis and counteract aging-related deterioration. This work was supported by Spanish Ministry of Science and Innovation and Agencia Estatal de Investigación plus FEDER Funds through grants PID2023-149767OB-I00 (FJM) and ‘Unidad de Excelencia María de Maeztu’ CEX2024-001431-M funded by MICIU/AEI/10.13039/501100011033 and by ’ERDF A way of making Europe’.