2. Academic Validation
  3. Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation

Pharmacologically blocking p53-dependent apoptosis protects intestinal stem cells and mice from radiation

  • Sci Rep. 2015 Apr 10;5:8566. doi: 10.1038/srep08566.
Xinwei Wang 1 2,  Liang Wei 1 2,  Julie M Cramer 1,  Brian J Leibowitz 1 2,  Colleen Judge 1 2,  Michael Epperly 2 3,  Joel Greenberger 2 3,  Fengchao Wang 4,  Linheng Li 4,  Matthias G Stelzner 5,  James C Y Dunn 6,  Martin G Martin 6,  Eric Lagasse 1,  Lin Zhang 2 7,  Jian Yu 1 2 3
Affiliations

Affiliations

  • 1 Department of Pathology, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Pittsburgh, PA 15213.
  • 2 University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA 15213.
  • 3 Department of Radiation Oncology, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Pittsburgh, PA 15213.
  • 4 Department of Pathology, University of Kansas Medical Center, Stowers Institute for Medical Research, 1000 E 50th Street, Kansas City, MS 64110.
  • 5 Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073.
  • 6 Departments of Surgery and Pediatrics, David Geffen School of Medicine, University of California, 10833 Le Conte Ave, Los Angeles, CA 90095.
  • 7 Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, 5117 Centre Avenue, Pittsburgh, PA 15213.
PMID: 25858503 DOI: 10.1038/srep08566
Abstract

Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced Apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 Inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked Apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically.

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