title: Oxidative stress-induced DNA damage and repair in human peripheral blood mononuclear cells: protective role of hemoglobin.
abstract: BACKGROUND
  DNA repair is a cellular defence mechanism responding to DNA damage caused in large part by oxidative stress. There is a controversy with regard to the effect of red blood cells on DNA damage and cellular response.
  
  
  OBJECTIVE
  To investigate the effect of red blood cells on H2O2-induced DNA damage and repair in human peripheral blood mononuclear cells.
  
  
  METHODS
  DNA breaks were induced in peripheral blood mononuclear cells by H2O2 in the absence or presence of red blood cells, red blood cells hemolysate or hemoglobin. DNA repair was measured by (3)H-thymidine uptake, % double-stranded DNA was measured by fluorometric assay of DNA unwinding. DNA damage was measured by the comet assay and by the detection of histone H2AX phosphorylation.
  
  
  RESULTS
  Red blood cells and red blood cells hemolysate reduced DNA repair in a dose-dependent manner. Red blood cells hemolysate reduced % double-stranded DNA, DNA damage and phosphorylation of histone H2AX. Hemoglobin had the same effect as red blood cells hemolysate on % double-stranded DNA.
  
  
  CONCLUSIONS
  Red blood cells, via red blood cells hemolysate and hemoglobin, reduced the effect of oxidative stress on peripheral blood mononuclear cell DNA damage and phosphorylation of histone H2AX. Consequently, recruitment of DNA repair proteins diminished with reduction of DNA repair. This suggests that anemia predisposes to increased oxidative stress induced DNA damage, while a higher hemoglobin level provides protection against oxidative-stress-induced DNA damage.
authors.affiliation: Department of Medicine E, Rabin Medical Center, Petah Tikva, Israel.
authors.forename: Anat
authors.initials: A
authors.lastname: Gafter-Gvili
authors.forename: Boris
authors.initials: B
authors.lastname: Zingerman
authors.forename: Benaya
authors.initials: B
authors.lastname: Rozen-Zvi
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Ori
authors.forename: Hefziba
authors.initials: H
authors.lastname: Green
authors.forename: Ido
authors.initials: I
authors.lastname: Lubin
authors.forename: Tsipora
authors.initials: T
authors.lastname: Malachi
authors.forename: Uzi
authors.initials: U
authors.lastname: Gafter
authors.forename: Michal
authors.initials: M
authors.lastname: Herman-Edelstein
mesh_terms: D020552:Comet Assay; D004247:DNA / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects; D004260:DNA Repair; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006461:Hemolysis / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation
chemical_list: C468783:H2AX protein, human; D006454:Hemoglobins; D006657:Histones; D004247:DNA; D006861:Hydrogen Peroxide