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Research Paper|Volume 7, Issue 2|pp 110—122

Structural chromosome abnormalities, increased DNA strand breaks and DNA strand break repair deficiency in dermal fibroblasts from old female human donors

Faiza Kalfalah1, Sabine Seggewiß1,2, Regina Walter1, Julia Tigges3, María Moreno-Villanueva4, Alexander Bürkle4, Sebastian Ohse5, Hauke Busch5,6,7, Melanie Boerries5,6,7, Barbara Hildebrandt2, Brigitte Royer-Pokora2, Fritz Boege1
  • 1Institute of Clinical Chemistry and Laboratory Diagnostics, Heinrich-Heine-University, Med. Faculty, Düsseldorf, Germany
  • 2Institute of Human Genetics and Anthropology, Heinrich-Heine-University, Med. Faculty, Düsseldorf, Germany
  • 3Leibniz Research Institute for Environmental Medicine (IUF), Düsseldorf, Germany
  • 4Molecular Toxicology Group, Dept. of Biology, University of Konstanz, Konstanz, Germany
  • 5Systems Biology of the Cellular Microenvironment Group, Institute of Molecular Medicine and Cell Research, University of Freiburg, Freiburg, Germany
  • 6German Cancer Research Centre (DKFZ), Heidelberg, Germany
  • 7German Cancer Consortium (DKTK), Freiburg, Germany
Received: December 22, 2014Accepted: January 1, 2015Published: February 4, 2015
https://doi.org/10.18632/aging.100723

Copyright: © 2015 Kalfalah et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Dermal fibroblasts provide a paradigmatic model of cellular adaptation to long-term exogenous stress and ageing processes driven thereby. Here we addressed whether fibroblast ageing analysed ex vivo entails genome instability. Dermal fibroblasts from human female donors aged 20–67 years were studied in primary culture at low population doubling. Under these conditions, the incidence of replicative senescence and rates of age-correlated telomere shortening were insignificant. Genome-wide gene expression analysis revealed age-related impairment of mitosis, telomere and chromosome maintenance and induction of genes associated with DNA repair and non-homologous end-joining, most notably XRCC4 and ligase 4. We observed an age-correlated drop in proliferative capacity and age-correlated increases in heterochromatin marks, structural chromosome abnormalities (deletions, translocations and chromatid breaks), DNA strand breaks and histone H2AX-phosphorylation. In a third of the cells from old and middle-aged donors repair of X-ray induced DNA strand breaks was impaired despite up-regulation of DNA repair genes. The distinct phenotype of genome instability, increased heterochromatinisation and (in 30% of the cases futile) up-regulation of DNA repair genes was stably maintained over several cell passages indicating that it represents a feature of geroconversion that is distinct from cellular senescence, as it does not encompass a block of proliferation