Comparative proteome analysis of splenic lymphocytes in senescence-accelerated mice

Abstract

Background: Senescence-accelerated mice (SAM) are commonly used as animal models for studying aging. To date, aging-related proteomes in the livers and brains of SAMP8 mice have been reported; however, spleen of SAM has not yet been used as material for studying the aging-related proteome despite its extremely important role in the progress of aging or aging-related diseases.

Objective: To identify proteins associated with aging or aging-related diseases in SAM.

Methods: Two-dimensional gel electrophoresis (2DE) was used to compare the proteomes of splenic lymphocytes from two strains of SAM (SAMP8 and SAMR1). Differentially expressed spots whose expression altered over twofold (p < 0.01) were identified by LC-MS/MS and database search.

Results: Identification results showed that 18 differentially expressed protein spots represented 14 different proteins known to be involved in aging- or aging disease-related pathways, i.e., annexin I, calgranulin B, transaldolase, isocitrate dehydrogenase, and an unnamed protein product were involved in oxidative stress and cell defense, phosphoglycerate mutase I, aldose reductase, carbonic anhydrase I and carbonic anhydrase II were involved in glycolytic energy metabolism and homeostasis, and macrophage capping protein and high mobility group box-1 protein were involved in infection and DNA damage.

Conclusion: 2DE combined with MS is effective for comparative proteome analysis of splenic lymphocytes of SAM to identify proteins closely involved in aging or aging-related diseases, especially immune diseases, and further functional studies of these proteins in SAM may throw some light on the study of biomarkers for aging or aging-related diseases.