title: Proteomic analysis of specific brain proteins in aged SAMP8 mice treated with alpha-lipoic acid: implications for aging and age-related neurodegenerative disorders.
abstract: Free radical-mediated damage to neuronal membrane components has been implicated in the etiology of Alzheimer's disease (AD) and aging. The senescence accelerated prone mouse strain 8 (SAMP8) exhibits age-related deterioration in memory and learning along with increased oxidative markers. Therefore, SAMP8 is a suitable model to study brain aging and, since aging is the major risk factor for AD and SAMP8 exhibits many of the biochemical findings of AD, perhaps as a model for and the early phase of AD. Our previous studies reported higher oxidative stress markers in brains of 12-month-old SAMP8 mice when compared to that of 4-month-old SAMP8 mice. Further, we have previously shown that injecting the mice with alpha-lipoic acid (LA) reversed brain lipid peroxidation, protein oxidation, as well as the learning and memory impairments in SAMP8 mice. Recently, we reported the use of proteomics to identify proteins that are expressed differently and/or modified oxidatively in aged SAMP8 brains. In order to understand how LA reverses the learning and memory deficits of aged SAMP8 mice, in the current study, we used proteomics to compare the expression levels and specific carbonyl levels of proteins in brains from 12-month-old SAMP8 mice treated or not treated with LA. We found that the expressions of the three brain proteins (neurofilament triplet L protein, alpha-enolase, and ubiquitous mitochondrial creatine kinase) were increased significantly and that the specific carbonyl levels of the three brain proteins (lactate dehydrogenase B, dihydropyrimidinase-like protein 2, and alpha-enolase) were significantly decreased in the aged SAMP8 mice treated with LA. These findings suggest that the improved learning and memory observed in LA-injected SAMP8 mice may be related to the restoration of the normal condition of specific proteins in aged SAMP8 mouse brain. Moreover, our current study implicates neurofilament triplet L protein, alpha-enolase, ubiquitous mitochondrial creatine kinase, lactate dehydrogenase B, and dihydropyrimidinase-like protein 2 in process associated with learning and memory of SAMP8 mice.
authors.affiliation: Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
authors.forename: H Fai
authors.initials: HF
authors.lastname: Poon
authors.forename: Susan A
authors.initials: SA
authors.lastname: Farr
authors.forename: Visith
authors.initials: V
authors.lastname: Thongboonkerd
authors.forename: Bert C
authors.initials: BC
authors.lastname: Lynn
authors.forename: William A
authors.initials: WA
authors.lastname: Banks
authors.forename: John E
authors.initials: JE
authors.lastname: Morley
authors.forename: Jon B
authors.initials: JB
authors.lastname: Klein
authors.forename: D Allan
authors.initials: DA
authors.lastname: Butterfield
mesh_terms: D000375:Aging / Q000235:genetics* / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry / Q000235:genetics* / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D020271:Heredodegenerative Disorders, Nervous System / Q000235:genetics* / Q000503:physiopathology*; D006868:Hydrolysis; D007091:Image Processing, Computer-Assisted; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000737:chemistry*; D040901:Proteomics; D008063:Thioctic Acid / Q000494:pharmacology*; D014357:Trypsin / Q000737:chemistry
chemical_list: D009419:Nerve Tissue Proteins; D008063:Thioctic Acid; D014357:Trypsin