title: DNA damage, poly(ADP-Ribose) polymerase activation, and phosphorylated histone H2AX expression during postnatal retina development in C57BL/6 mouse.
abstract: OBJECTIVE
  The purpose of this study was to investigate the incidence of DNA damage during postnatal development of the retina and the relationship between DNA damage and cell death.
  
  
  METHODS
  DNA damage in the developing postnatal retina of C57BL/6 mice was assessed by determining the amounts of 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is indicative of DNA oxidation and related to the formation of DNA single-strand breaks (SSBs), and phosphorylated histone H2AX (γ-H2AX), a marker of DNA double-strand breaks (DSBs). Poly(ADP-ribose) polymerase (PARP) activation was measured by ELISA and Western blotting. The location of γ-H2AX-positive and dying cells was determined by immunofluorescence and TUNEL assays.
  
  
  RESULTS
  Oxidative DNA damage was maintained at low levels during high PARP activation between postnatal days 0 (P0) and P7. Phosphorylated histone H2AX gradually increased between P0 and P14 and decreased thereafter. Phosphorylated histone H2AX-positive cells with cell death morphology or TUNEL positivity were more abundant at P7 than at P14.
  
  
  CONCLUSIONS
  Oxidative DNA damage in postnatal retina increases during development. It is low during the first postnatal week when PARP-1 activity is high but increases thereafter. The rise in DSBs when PARP activity is downregulated may be attributable to accumulated oxidative damage and SSBs. At P7 and P14, γ-H2AX-positive cells are repairing naturally occurring DNA damage, but some are dying (mostly at P7), probably due to an accumulation of irreparable DNA damage.
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: David
authors: D
authors: Martín-Oliva
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Sandra M
authors: SM
authors: Martín-Guerrero
authors: Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences (FHMS), University of Surrey, Guildford, United Kingdom.
authors: Ana M
authors: AM
authors: Matia-González
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Rosa M
authors: RM
authors: Ferrer-Martín
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: María
authors: M
authors: Martín-Estebané
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: María-Carmen
authors: MC
authors: Carrasco
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Ana
authors: A
authors: Sierra
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: José L
authors: JL
authors: Marín-Teva
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Ruth
authors: R
authors: Calvente
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Julio
authors: J
authors: Navascués
authors: Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
authors: Miguel A
authors: MA
authors: Cuadros
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis; D015153:Blotting, Western; D004247:DNA / Q000235:genetics*; D004249:DNA Damage / Q000235:genetics*; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000096:biosynthesis / Q000235:genetics*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D051379:Mice; D008810:Mice, Inbred C57BL; D000071137:Poly (ADP-Ribose) Polymerase-1; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000096:biosynthesis / Q000235:genetics*; D012160:Retina / Q000254:growth & development*
chemical_list: D004247:DNA; D006657:Histones; D000071137:Poly (ADP-Ribose) Polymerase-1; D011064:Poly Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases; C499321:Parp1 protein, mouse; C475961:gamma-H2AX protein, mouse
keywords: DNA damage; PARP-1; postnatal development; retina; γ-H2AX