Proteomic study of neuron and astrocyte cultures from senescence accelerated mouse SAMP8

Senescente-accelerated prone (SAMP) strain 8 mice suffer an earlier development of cognitive aging-related pathologies and a shorter life span than conventional mice. Protein alterations in astrocytes, in addition to those in neurons, may contribute to neurodegenerative damage. We used proteomics to study cell-specific early markers of brain aging-related degeneration in SAMP8. The 2-D protein expression patterns of SAMP8 neuron and astrocyte cultures were compared to those obtained from the senescence-resistant strain 1 (SAMR1) cultures. Differentially expressed proteins identified by MALDI–TOF MS in both cell types belonged to cell pathways of energy metabolism, biosynthesis, cell transduction and signaling, stress response and the maintenance of the cytoskeletal functions. Most changes detected were cell type specific, but there was a general trend of increase of cell transduction, signaling and stress-related proteins and decrease of cytokeletal proteins. Also, neurons showed an increase of the expression of several proteins involved in biosynthetic pathways. As a whole, the alterations of their proteoma indicated that both cell types are involved in the brain degenerative changes of SAMP8 mice, but network analysis suggests that neuronal changes are more complex and influencing. Cell culture proteomics is a powerful tool to discern cell specific changes and contributions to aging-related neuropathologies.