Proteome-Level Autophagy-Lysosome Remodelling Marks Ageing in Human Dermal Fibroblasts and Nominates Hydroxytyrosol as a Candidate Nutraceutical.

Autophagy-lysosome dysfunction accompanies dermal fibroblast ageing, yet whether remodelling is transcriptional or post-transcriptional in primary human cells remains unresolved. We reanalysed the Genetic and Epigenetic Signatures of Translational Ageing Laboratory Testing(GESTALT) paired RNA sequencing (RNA-seq) and tandem mass tag (TMT) proteome from 82 donors (aged 22-89) using Data Integration Analysis for Biomarker discovery using Latent cOmponents (DIABLO) for supervised multi-omics integration, weighted gene co-expression network analysis (WGCNA), external Genotype-Tissue Expression(GTEx) transcriptomic comparison, network medicine proximity mapping and CDOCKER molecular docking. Three analyses converged on the autophagy-lysosome axis: Kyoto Encyclopaedia of Genes and Genomes (KEGG) Lysosome ranked first in discordant-quadrant analysis; gene set enrichment analysis (GSEA) identified vacuole organisation and macroautophagy as the top age-upregulated Gene Ontology (GO) terms; and WGCNA recovered KEGG Lysosome in the brown module. Module regression localised most proteomic age signals to the lysosomal degradative-capacity module, whereas the proteasome was unaffected. McNemar testing and GTEx comparison supported a protein-side, post-transcriptional origin. TCIRG1, CTSA and ATP6V0D1 were recurrent hubs. Network proximity computationally prioritised hydroxytyrosol as a lysosomal-degradative-capacity-preferential candidate, and CDOCKER on cathepsin A linked its advantage over tyrosol to an ortho-hydroxyl group forming additional hydrogen bonds. These results support protein-layer-dominant autophagy-lysosome remodelling as a feature of dermal fibroblast ageing and suggest a cell-type-resolved computational route from ageing proteomics to testable dietary candidates.