IRF3 activates RB to authorize cGAS-STING-induced senescence and mitigate liver fibrosis

Sci Adv. 2024 Mar;10(9):eadj2102. doi: 10.1126/sciadv.adj2102. Epub 2024 Feb 28.

Abstract

Cytosolic double-stranded DNA surveillance by cyclic GMP-AMP synthase (cGAS)-Stimulator of Interferon Genes (STING) signaling triggers cellular senescence, autophagy, biased mRNA translation, and interferon-mediated immune responses. However, detailed mechanisms and physiological relevance of STING-induced senescence are not fully understood. Here, we unexpectedly found that interferon regulatory factor 3 (IRF3), activated during innate DNA sensing, forms substantial endogenous complexes in the nucleus with retinoblastoma (RB), a key cell cycle regulator. The IRF3-RB interaction attenuates cyclin-dependent kinase 4/6 (CDK4/6)-mediated RB hyperphosphorylation that mobilizes RB to deactivate E2 family (E2F) transcription factors, thereby driving cells into senescence. STING-IRF3-RB signaling plays a notable role in hepatic stellate cells (HSCs) within various murine models, pushing activated HSCs toward senescence. Accordingly, IRF3 global knockout or conditional deletion in HSCs aggravated liver fibrosis, a process mitigated by the CDK4/6 inhibitor. These findings underscore a straightforward yet vital mechanism of cGAS-STING signaling in inducing cellular senescence and unveil its unexpected biology in limiting liver fibrosis.

MeSH terms

  • Animals
  • DNA / metabolism
  • Interferon Regulatory Factor-3 / genetics
  • Interferon Regulatory Factor-3 / metabolism
  • Interferons / metabolism
  • Mice
  • Nucleotidyltransferases / genetics
  • Nucleotidyltransferases / metabolism
  • Retinal Neoplasms*
  • Retinoblastoma*

Substances

  • Interferon Regulatory Factor-3
  • Nucleotidyltransferases
  • DNA
  • Interferons