title: Preferential reduction of the alpha-2-6-sialylation from cell surface N-glycans of human diploid fibroblastic cells by in vitro aging.
abstract: Human diploid fibroblastic cell line, TIG-3, has a finite life span of about 80 population doubling levels (PDL), and is used for in vitro aging studies. Young cells (PDL 23) grew to higher cell densities at a higher growth rate than aged cells (PDL 77). When the electrophoretic mobility of cells was determined, the negative surface charge of the aged cells decreased significantly when compared to that of young cells. Lectin blot analysis of membrane glycoproteins showed that the alpha-2-6-sialylation but not the alpha-2-3-sialylation of N-glycans decreases markedly in the aged cells when compared to the young cells. In support of this observation, the cDNA microarray assay and reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that the gene expression of the alpha-2,6-sialyltransferase I (ST6Gal I), which transfers sialic acid to galactose residues of N-glycans, decreases in the aged cells. These results indicate that the concordant decrease of the alpha-2,6-sialylation of N-glycans with the ST6Gal I gene expression is induced in TIG-3 cells by in vitro aging.
authors.affiliation: Department of Biosignal Research, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Tadokoro
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Iku
authors.initials: I
authors.lastname: Kuwahara
authors.forename: Hirosuke
authors.initials: H
authors.lastname: Fujisawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikekita
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Taniguchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sato
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Furukawa
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D016922:Cellular Senescence / Q000502:physiology*; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism*; D009584:Nitrogen / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D012799:Sialyltransferases / Q000378:metabolism*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D011134:Polysaccharides; D012799:Sialyltransferases; D019158:N-Acetylneuraminic Acid; D009584:Nitrogen; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase