PLoS ONE (Jan 2014)

Polμ deficiency increases resistance to oxidative damage and delays liver aging.

  • Beatriz Escudero,
  • Daniel Lucas,
  • Carmen Albo,
  • Suveera Dhup,
  • Jeff W Bacher,
  • Aránzazu Sánchez-Muñoz,
  • Margarita Fernández,
  • José Rivera-Torres,
  • Rosa M Carmona,
  • Encarnación Fuster,
  • Candelas Carreiro,
  • Raquel Bernad,
  • Manuel A González,
  • Vicente Andrés,
  • Luis Blanco,
  • Enrique Roche,
  • Isabel Fabregat,
  • Enrique Samper,
  • Antonio Bernad

DOI
https://doi.org/10.1371/journal.pone.0093074
Journal volume & issue
Vol. 9, no. 4
p. e93074

Abstract

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Polμ is an error-prone PolX polymerase that contributes to classical NHEJ DNA repair. Mice lacking Polμ (Polμ(-/-)) show altered hematopoiesis homeostasis and DSB repair and a more pronounced nucleolytic resection of some V(D)J junctions. We previously showed that Polμ(-/-) mice have increased learning capacity at old ages, suggesting delayed brain aging. Here we investigated the effect of Polμ(-/-) deficiency on liver aging. We found that old Polμ(-/-) mice (>20 month) have greater liver regenerative capacity compared with wt animals. Old Polμ(-/-) liver showed reduced genomic instability and increased apoptosis resistance. However, Polμ(-/-) mice did not show an extended life span and other organs (e.g., heart) aged normally. Our results suggest that Polμ deficiency activates transcriptional networks that reduce constitutive apoptosis, leading to enhanced liver repair at old age.