NF-κB activation impairs somatic cell reprogramming in ageing

Abstract

Ageing constitutes a critical impediment to somatic cell reprogramming. We have explored the regulatory mechanisms that constitute age-associated barriers, through derivation of induced pluripotent stem cells (iPSCs) from individuals with premature or physiological ageing. We demonstrate that NF-κB activation blocks the generation of iPSCs in ageing. We also show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs the generation of iPSCs by eliciting the reprogramming repressor DOT1L, which reinforces senescence signals and downregulates pluripotency genes. Genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo progeria syndrome and Hutchinson-Gilford progeria syndrome patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo extends lifespan and ameliorates the accelerated ageing phenotype of progeroid mice, supporting the interest of studying age-associated molecular impairments to identify targets of rejuvenation strategies.

Reprogramming aging through DOT1L inhibition

“…4 Accordingly, we have provided evidence for a direct regulation of DOT1L and YY1 genes by NF-kB, and a striking over-expression of DOT1L in NGPS fibroblasts, suggesting that these proteins might be relevant effectors of NF-kB role in cellular reprogramming as well as in NF-kB-driven alterations. 2 Additionally, the administration of a specific DOT1L chemical inhibitor remarkably increased the reprogramming efficiency of NGPS fibroblasts. 2 Furthermore, the parallelism observed between rejuvenation and reprogramming enhancement through NF-kB inhibition suggested that DOT1L could be a novel target for rejuvenation-based approaches (Fig.…”

“…2 Additionally, the administration of a specific DOT1L chemical inhibitor remarkably increased the reprogramming efficiency of NGPS fibroblasts. 2 Furthermore, the parallelism observed between rejuvenation and reprogramming enhancement through NF-kB inhibition suggested that DOT1L could be a novel target for rejuvenation-based approaches (Fig. 1).…”

“…We also extended these results to cells from patients with other progeroid syndromes and from physiologically aged donors, thereby supporting the key relevance of NF-kB signaling in the maintenance of cellular identity. 2 Nevertheless, the putative NF-kB targets controlling this newly identified ageassociated reprogramming barrier were completely unknown. In this regard, previous studies have uncovered new chromatin-modifying proteins such as DOT1L and YY1 that function as reprogramming repressors.…”

“…2 The methylation of H3K79 by DOT1L which is a conserved epigenetic mark in many eukaryotic epigenomes, increases progressively along the aging process, suggesting that DOT1L might function as a vital clock, ticking the hours impassively. 6 The results discussed herein demonstrate the critical involvement of DOT1L in aging pathogenesis and provide the first in vivo evidence about the efficacy of DOT1L-inhibitory strategies to treat ageassociated alterations, demonstrating the utility of studying age-associated reprogramming barriers for the development of anti-aging therapies.…”

“…2 Our studies in this regard were first focused on the generation of iPSCs from fibroblasts of patients with NestorGuillermo progeria syndrome (NGPS), a severe disease caused by a homozygous mutation in the BANF1 gene (c.34G>C; p.A12T). 3 We found that NGPS fibroblasts showed an increased NF-kB signaling in comparison with control cells, which could contribute to their premature senescence phenotype.…”