XPF-ERCC1 endonuclease is required for repair of helix-distorting DNA lesions and cytotoxic DNA interstrand crosslinks. Mild mutations in XPF cause the cancer-prone syndrome xeroderma pigmentosum. A patient presented with a severe XPF mutation leading to profound crosslink sensitivity and dramatic progeroid symptoms. It is not known how unrepaired DNA damage accelerates ageing or its relevance to natural ageing. Here we show a highly significant correlation between the liver transcriptome of old mice and a mouse model of this progeroid syndrome. Expression data from XPF-ERCC1-deficient mice indicate increased cell death and anti-oxidant defences, a shift towards anabolism and reduced growth hormone/insulin-like growth factor 1 (IGF1) signalling, a known regulator of lifespan. Similar changes are seen in wild-type mice in response to chronic genotoxic stress, caloric restriction, or with ageing. We conclude that unrepaired cytotoxic DNA damage induces a highly conserved metabolic response mediated by the IGF1/insulin pathway, which re-allocates resources from growth to somatic preservation and life extension. This highlights a causal contribution of DNA damage to ageing and demonstrates that ageing and end-of-life fitness are determined both by stochastic damage, which is the cause of functional decline, and genetics, which determines the rates of damage accumulation and decline.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Dec 21 2006|
Bibliographical noteFunding Information:
Acknowledgements This research was supported by the National Institute of Aging Program, the Dutch Cancer Society, the Dutch Science Foundation (NWO) through the foundation of the Research Institute Diseases of the Elderly, as well as grants from SenterNovem IOP-Genomics, the NIH, the NIA Program Project, the NIEHS center, the EC, and Human Frontier Science Program. J.H.J.H. is chief scientific officer of DNage. L.J.N. was supported by a postdoctoral fellowship from the American Cancer Society and subsequently by the NCI and The Ellison Medical Foundation, along with A.R.R. and A.A. We thank P. Nair, F. J. Calderon, R. B. Calder and D. Muñoz-Medellin of the Sam and Ann Barshop Center, University of Texas Health Science Center, for their contributions to the preliminary microarray analysis.