Age-associated neurodegeneration is the subject of intense research, in the hope of decreasing the incidence of mentally disabling diseases in the elder population. Alzheimer's disease (AD) is the most common age-related neurodegenerative disease with an estimated 26 million people living with the condition worldwide. This number will quadruplicate by 2050.The senescence-accelerated prone mouse strain 8 (SAMP8) is an established animal model for studying age- Abbreviations used: AD, Alzheimer's disease; Aldh2, aldehyde dehydrogenase; Cox, cytochrome oxidase; FBS, fetal bovine serum; HPI, human protein interactome; IPG, Immobilized pH Gradient; PMF, peptide mass fingerprint; PP1, serine/threonine-protein phosphatase type 1; Ppp1ca, Serine/threonine-protein phosphatase PP1-a catalytic subunit; SAMP8, senescence-accelerated prone mouse strain 8; SAMR1, senescence-accelerated resistant mouse strain 1; SDS, sodium dodecyl sulfate.
AbstractSenescence-accelerated prone (SAMP) strain 8 mice suffer an earlier development of cognitive age-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 applied proteomics techniques to study cell-specific early markers of brain aging-related degeneration in SAMP8. The two-dimensional protein expression patterns of the SAMP8 neuron and astrocyte cultures were compared with those obtained from senescence-accelerated resistant mouse strain 1 cultures. Differentially expressed spots were identified by matrix-assisted laser desorption/ionization-time of flight peptide map fingerprinting and database search. Proteins belonged to cell pathways of energy metabolism, biosynthesis, cell transduction and signaling, stress response, and the maintenance of cytoskeletal functions. Most of the changes were cell type specific. However, there was a general increase in cell transduction, signaling, and stress-related proteins and a decrease in cytoskeletal proteins. In addition, neurons showed an increased expression of proteins involved in biosynthetic pathways. A number of the protein alterations have been previously reported in the brain tissue proteome of SAMP8, aged brain or Alzheimer's disease brain. Alterations in neuron and astrocyte proteoma indicated that both cell types are involved in the brain degenerative changes of SAMP8 mice. However, network analysis suggests that neuronal changes are more complex and have a greater influence. Keywords: Alzheimer's disease, brain aging, differential proteomics, neuron and astrocyte cultures, senescenceaccelerated prone mouse strain 8. 2009). SAMP8 was obtained through phenotypic selection from a common genetic pool of AKR/J mice. It has a shorter life span than the reference strain (senescence-accelerated resistant mouse strain 1; SAMR1) and suffers age-related cognitive impairment (Takeda 1999(Takeda , 2009
Materials and methods
Animals and reagentsSenescence-accelerated resistant mouse strain 1 and SAMP8 mouse breeders we...