iScience (Dec 2022)

PERIOD 2 regulates low-dose radioprotection via PER2/pGSK3β/β-catenin/Per2 loop

  • Aris T. Alexandrou,
  • Yixin Duan,
  • Shanxiu Xu,
  • Clifford Tepper,
  • Ming Fan,
  • Jason Tang,
  • Jonathan Berg,
  • Wassim Basheer,
  • Tyler Valicenti,
  • Paul F. Wilson,
  • Matthew A. Coleman,
  • Andrew T. Vaughan,
  • Loning Fu,
  • David J. Grdina,
  • Jefferey Murley,
  • Aijun Wang,
  • Gayle Woloschak,
  • Jian Jian Li

Journal volume & issue
Vol. 25, no. 12
p. 105546

Abstract

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Summary: During evolution, humans are acclimatized to the stresses of natural radiation and circadian rhythmicity. Radiosensitivity of mammalian cells varies in the circadian period and adaptive radioprotection can be induced by pre-exposure to low-level radiation (LDR). It is unclear, however, if clock proteins participate in signaling LDR radioprotection. Herein, we demonstrate that radiosensitivity is increased in mice with the deficient Period 2 gene (Per2def) due to impaired DNA repair and mitochondrial function in progenitor bone marrow hematopoietic stem cells and monocytes. Per2 induction and radioprotection are also identified in LDR-treated Per2wt mouse cells and in human skin (HK18) and breast (MCF-10A) epithelial cells. LDR-boosted PER2 interacts with pGSK3β(S9) which activates β-catenin and the LEF/TCF mediated gene transcription including Per2 and genes involved in DNA repair and mitochondrial functions. This study demonstrates that PER2 plays an active role in LDR adaptive radioprotection via PER2/pGSK3β/β-catenin/Per2 loop, a potential target for protecting normal cells from radiation injury.

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