title: The role of the DNA damage response in zebrafish and cellular models of Diamond Blackfan anemia.
abstract: Ribosomal biogenesis involves the processing of pre-ribosomal RNA. A deficiency of some ribosomal proteins (RPs) impairs processing and causes Diamond Blackfan anemia (DBA), which is associated with anemia, congenital malformations and cancer. p53 mediates many features of DBA, but the mechanism of p53 activation remains unclear. Another hallmark of DBA is the upregulation of adenosine deaminase (ADA), indicating changes in nucleotide metabolism. In RP-deficient zebrafish, we found activation of both nucleotide catabolism and biosynthesis, which is consistent with the need to break and replace the faulty ribosomal RNA. We also found upregulation of deoxynucleotide triphosphate (dNTP) synthesis - a typical response to replication stress and DNA damage. Both RP-deficient zebrafish and human hematopoietic cells showed activation of the ATR/ATM-CHK1/CHK2/p53 pathway. Other features of RP deficiency included an imbalanced dNTP pool, ATP depletion and AMPK activation. Replication stress and DNA damage in cultured cells in non-DBA models can be decreased by exogenous nucleosides. Therefore, we treated RP-deficient zebrafish embryos with exogenous nucleosides and observed decreased activation of p53 and AMPK, reduced apoptosis, and rescue of hematopoiesis. Our data suggest that the DNA damage response contributes to p53 activation in cellular and zebrafish models of DBA. Furthermore, the rescue of RP-deficient zebrafish with exogenous nucleosides suggests that nucleoside supplements could be beneficial in the treatment of DBA.
authors.affiliation: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA. ndanilova@ucla.edu shuolin@ucla.edu.
authors.forename: Nadia
authors.initials: N
authors.lastname: Danilova
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Bibikova
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Covey
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA.
authors.forename: David
authors.initials: D
authors.lastname: Nathanson
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dimitrova
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
authors.forename: Yoan
authors.initials: Y
authors.lastname: Konto
authors.affiliation: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Lindgren
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
authors.forename: Bertil
authors.initials: B
authors.lastname: Glader
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California, Los Angeles, CA 90095, USA.
authors.forename: Caius G
authors.initials: CG
authors.lastname: Radu
authors.affiliation: Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305-5208, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Sakamoto
authors.affiliation: Department of Molecular, Cell & Developmental Biology, University of California, Los Angeles, CA 90095, USA. ndanilova@ucla.edu shuolin@ucla.edu.
authors.forename: Shuo
authors.initials: S
authors.lastname: Lin
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000263:Adenylate Kinase / Q000378:metabolism; D029503:Anemia, Diamond-Blackfan / Q000196:embryology / Q000235:genetics / Q000473:pathology*; D000818:Animals; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000473:pathology; D005333:Fetus / Q000473:pathology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008954:Models, Biological; D009705:Nucleosides / Q000494:pharmacology; D012264:Ribonucleotide Reductases / Q000378:metabolism; D012269:Ribosomal Proteins / Q000172:deficiency / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000378:metabolism
chemical_list: D009705:Nucleosides; D012269:Ribosomal Proteins; D029961:Zebrafish Proteins; D000255:Adenosine Triphosphate; D012264:Ribonucleotide Reductases; D000263:Adenylate Kinase
keywords: AMPK; ATP; ATR; Chk1; Exogenous nucleosides; RNR; Ribosomal protein deficiency; Rpl11; Rps19; p53