title: Age-dependent variations of cell response to oxidative stress: proteomic approach to protein expression and phosphorylation.
abstract: We investigated the protein profiles of variously aged rat astrocytes in response to oxidative stress. After H2O2-exposure of cells at 100 microM for 30 min, the relative intensity of ten protein spots changed on two-dimensional (2-D) gels compared with control gels after silver staining. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis after in-gel digestion revealed that six of these spots corresponded to three kinds of proteins, each of which was composed of a protein and its modified form with a different isoelectric point (pI). These three proteins were identified as peroxiredoxins (PRDXs) II and III, and calpactin I light chain (p11). H2O2-exposure increased the intensity of the spot with lower pI and simultaneously decreased that of the spot with higher pI for both PRDXs II and III. In addition, the expression of annexin VII, S-adenosyl-L-homocysteine hydrolase, elongation factor II fragment (EF-II), and adenosine deaminase was increased by H2O2-exposure in astrocytes from variously aged rats. Using the Pro-Q Diamond staining, heat shock protein 60 kDa (Hsp 60) and alpha-tubulin were observed to be phosphorylated upon H2O2-exposure. While phosphorylation of alpha-tubulin was correlated positively with age, the changes in abundance of ten protein spots as described above were independent of age. These results suggest that aging does not suppress the responses aimed at limiting injury and promoting repair brought about by severe oxidative stress, and might affect cell dynamics including the formation of microtubules.
authors.affiliation: Redox Regulation Research Group, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo, Japan. miura@center.tmig.or.jp
authors.forename: Yuri
authors.initials: Y
authors.lastname: Miura
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kano
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Abe
authors.forename: Shiro
authors.initials: S
authors.lastname: Urano
authors.forename: Shozo
authors.initials: S
authors.lastname: Suzuki
authors.forename: Tosifusa
authors.initials: T
authors.lastname: Toda
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects; D016922:Cellular Senescence; D005260:Female; D018384:Oxidative Stress; D010766:Phosphorylation; D011506:Proteins / Q000032:analysis / Q000378:metabolism*; D040901:Proteomics; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014867:Water / Q000494:pharmacology
chemical_list: D011506:Proteins; D014867:Water