Global and tissue-specific aging effects on murine proteomes

ABSTRACT Maintenance of protein homeostasis degrades with age, contributing to aging-related decline and disease. Previous studies have primarily surveyed transcriptional changes with age. To define the effects of age directly at the protein level, we performed discovery-based proteomics in 10 tissues from 20 C57BL/6J mice, representing both sexes at adult and late midlife ages (8 and 18 months). Consistent with previous studies, age-related changes in protein abundance often have no corresponding transcriptional change. Aging resulted in increases in immune protein abundance across all tissues, consistent with a global pattern of immune infiltration with age. Our protein-centric data revealed tissue-specific aging changes with potential functional consequences, including altered endoplasmic reticulum and protein trafficking in the spleen. We further observed changes in the stoichiometry of protein complexes with important roles in protein homeostasis such as the CCT/TriC complex and large ribosomal subunit. These data provide a foundation for understanding how proteins contribute to systemic aging across tissues.