Calorie restriction (CR) reduces age-dependent decline of non-homologous end joining (NHEJ) activity in rat tissues

► CR reduced age-dependent decline of NHEJ activity in the lung, liver, kidney and spleen of rats. ► CR also appeared to reduce age-dependent decline of XRCC4 protein level. ► CR could reduce age-dependent decline of NHEJ activity in various tissues of rats possibly through up-regulation of XRCC4.