Absolute Proteome Analysis of Hippocampus, Cortex and Cerebellum in Aged and Young Mice Reveals Changes in Energy Metabolism

Aging is associated with a general decline of cognitive functions, and it is widely accepted that this decline results from changes in the expression of proteins involved in regulation of synaptic plasticity. However, several lines of evidence have accumulated that suggest that the impaired function of the aged brain may be related to significant alterations in the energy metabolism. In the current study, we employed the label-free "Total protein approach" (TPA) method to focus on the similarities and differences in energy metabolism proteomes of young (1-month-old) and aged (22-month-old) murine brains. We quantified over 7000 proteins in each of the following three analyzed brain structures: the hippocampus, the cerebral cortex and the cerebellum. To the best of our knowledge, this is the most extensive quantitative proteomic description of energy metabolism pathways during the physiological aging of mice. The analysis demonstrates that aging does not significantly affect the abundance of total proteins in the studied brain structures, however, the levels of proteins constituting energy metabolism pathways differ significantly between young and aged mice.