CSB promoter downregulation via histone H3 hypoacetylation is an early determinant of replicative senescence

Nat Commun. 2019 Dec 6;10(1):5576. doi: 10.1038/s41467-019-13314-y.


Cellular senescence has causative links with ageing and age-related diseases, however, it remains unclear if progeroid factors cause senescence in normal cells. Here, we show that depletion of CSB, a protein mutated in progeroid Cockayne syndrome (CS), is the earliest known trigger of p21-dependent replicative senescence. CSB depletion promotes overexpression of the HTRA3 protease resulting in mitochondrial impairments, which are causally linked to CS pathological phenotypes. The CSB promoter is downregulated by histone H3 hypoacetylation during DNA damage-response. Mechanistically, CSB binds to the p21 promoter thereby downregulating its transcription and blocking replicative senescence in a p53-independent manner. This activity of CSB is independent of its role in the repair of UV-induced DNA damage. HTRA3 accumulation and senescence are partially rescued upon reduction of oxidative/nitrosative stress. These findings establish a CSB/p21 axis that acts as a barrier to replicative senescence, and link a progeroid factor with the process of regular ageing in human.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cellular Senescence / genetics
  • Cellular Senescence / physiology*
  • Cockayne Syndrome / genetics
  • Cockayne Syndrome / metabolism*
  • Cockayne Syndrome / pathology
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism
  • DNA / metabolism
  • DNA / radiation effects
  • DNA Damage
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • DNA Repair
  • DNA Repair Enzymes / genetics
  • DNA Repair Enzymes / metabolism*
  • Down-Regulation
  • Epigenomics
  • Fibroblasts
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • HEK293 Cells
  • Histones / metabolism*
  • Humans
  • Mitochondria / metabolism
  • Oxidative Stress
  • Poly-ADP-Ribose Binding Proteins / genetics
  • Poly-ADP-Ribose Binding Proteins / metabolism*
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / metabolism
  • Transcriptome
  • Ultraviolet Rays / adverse effects


  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • Histones
  • Poly-ADP-Ribose Binding Proteins
  • DNA
  • HTRA3 protein, human
  • Serine Endopeptidases
  • DNA Helicases
  • ERCC6 protein, human
  • DNA Repair Enzymes