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Updated: Jul 17, 2025

Evaluation of Injury-induced Senescence and In Vivo Reprogramming in the Skeletal Muscle
Published on: October 26, 2017
p16High senescence restricts cellular plasticity during somatic cell reprogramming
Bogdan B Grigorash1,2, Dominic van Essen1, Guixian Liang3,4
1Institute for Research on Cancer and Aging of Nice (IRCAN), Université Côte d'Azur, INSERM, CNRS, Nice, France.
Abstract:
Despite advances in four-factor (4F)-induced reprogramming (4FR) in vitro and in vivo, how 4FR interconnects with senescence remains largely under investigated. Here, using genetic and chemical approaches to manipulate senescent cells, we show that removal of p16High cells resulted in the 4FR of somatic cells into totipotent-like stem cells. These cells expressed markers of both pluripotency and the two-cell embryonic state, readily formed implantation-competent blastoids and, following morula aggregation, contributed to embryonic and extraembryonic lineages. We identified senescence-dependent regulation of nicotinamide N-methyltransferase as a key mechanism controlling the S-adenosyl-L-methionine levels during 4FR that was required for expression of the two-cell genes and acquisition of an extraembryonic potential. Importantly, a partial 4F epigenetic reprogramming in old mice was able to reverse several markers of liver aging only in conjunction with the depletion of p16High cells. Our results show that the presence of p16High senescent cells limits cell plasticity, whereas their depletion can promote a totipotent-like state and histopathological tissue rejuvenation during 4F reprogramming.
Insights
Removing senescent cells enhances four-factor reprogramming (4FR) of somatic cells into totipotent-like stem cells. This process rejuvenates aged tissues by promoting cell plasticity and reversing aging markers.
Area of Science:
- Cellular reprogramming
- Aging biology
- Stem cell research
Background:
- Four-factor reprogramming (4FR) advances in vitro and in vivo, but its interplay with cellular senescence is understudied.
- Senescence, a state of irreversible cell cycle arrest, is linked to aging and tissue dysfunction.
Purpose of the Study:
- To investigate the role of senescent cells in 4FR.
- To explore the potential of manipulating senescence for regenerative purposes.
Main Methods:
- Genetic and chemical depletion of p16High senescent cells.
- Four-factor reprogramming of somatic cells.
- Analysis of pluripotency markers, two-cell embryonic state markers, blastoid formation, and embryonic/extraembryonic lineage contribution.
- Investigation of nicotinamide N-methyltransferase regulation and S-adenosyl-L-methionine levels.
- Partial 4F epigenetic reprogramming in aged mice with and without senescent cell depletion.
Main Results:
- Depletion of p16High senescent cells enabled 4FR into totipotent-like stem cells expressing pluripotency and two-cell embryonic markers.
- These reprogrammed cells formed implantation-competent blastoids and contributed to embryonic lineages.
- Senescence-dependent regulation of nicotinamide N-methyltransferase was identified as crucial for 4FR and extraembryonic potential.
- Partial 4FR combined with senescent cell depletion reversed liver aging markers in old mice.
Conclusions:
- p16High senescent cells restrict cell plasticity during 4FR.
- Senescent cell depletion promotes a totipotent-like state and tissue rejuvenation.
- Targeting senescence is a viable strategy to enhance reprogramming and combat aging.
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