title: Telomere erosion varies during in vitro aging of normal human fibroblasts from young and adult donors.
abstract: The life span of normal fibroblasts in vitro (Hayflick limit) depends on donor age, and telomere shortening has been proposed as a potential mechanism. By quantitative fluorescence in situ hybridization and Southern blot analysis, we show progressive telomere loss to about 5 kb mean telomere restriction fragment length in fibroblasts from two adult donors within 40 population doublings, whereas in fibroblasts from two infant donors, telomere erosion is reduced, leaving a mean telomere restriction fragment length of approximately 7 kb at senescence (after approximately 60 population doublings). Aging of fibroblasts from both infant and adult donors was not accompanied by chromosomal abnormalities but was correlated with increased telomere repeat-binding factor 2 expression at both the protein and transcriptional level.
authors.affiliation: Division of Carcinogenesis and Differentiation, German Cancer Research Center, Heidelberg.
authors.forename: R
authors.initials: R
authors.lastname: Figueroa
authors.forename: H
authors.initials: H
authors.lastname: Lindenmaier
authors.forename: M
authors.initials: M
authors.lastname: Hergenhahn
authors.forename: K V
authors.initials: KV
authors.lastname: Nielsen
authors.forename: P
authors.initials: P
authors.lastname: Boukamp
mesh_terms: D000328:Adult; D000375:Aging; D015139:Blotting, Southern; D015153:Blotting, Western; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism* / Q000648:ultrastructure*; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016615:Telomere / Q000648:ultrastructure*; D035341:Telomeric Repeat Binding Protein 2; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D016376:Oligonucleotides, Antisense; D035341:Telomeric Repeat Binding Protein 2