title: Neuroglobin protection in retinal ischemia.
abstract: OBJECTIVE
  Neuroglobin (Ngb) is a vertebrate globin that is predominantly expressed in the retina and brain. To explore the role of Ngb in retinal neuroprotection during ischemia reperfusion (IR), the authors examined the effect of Ngb overexpression in the retina in vivo by using Ngb-transgenic (Ngb-Tg) mice.
  
  
  METHODS
  Retinal IR was induced in Ngb overexpressing Ngb-Tg mice and wild type (WT) mice by cannulating the anterior chamber and transiently elevating the IOP for 60 minutes. After Day 7 of reperfusion, the authors evaluated Ngb mRNA and protein expression in nonischemic control as well as ischemic mice and its effect on retinal histology, mitochondrial oxidative stress, and apoptosis, using morphometry and immunohistochemistry, quantitative PCR analysis and Western blot techniques.
  
  
  RESULTS
  Ngb-Tg mice without ischemia overexpress Ngb mRNA 11.3-fold (SE ± 0.457, P < 0.05) higher than WT control mice, and this overexpression of Ngb protein was localized to the mitochondria of the ganglion cells, outer and inner plexiform layers, and photoreceptor inner segments. This overexpression of Ngb is associated with decreased mitochondrial DNA damage in Ngb-Tg mice with IR in comparison with WT. Ngb-Tg mice with IR also revealed significant preservation of retinal thickness, significantly less activated caspase 3 protein expression, and apoptosis in comparison with WT mice.
  
  
  CONCLUSIONS
  Neuroglobin overexpression plays a neuroprotective role against retinal ischemia reperfusion injury due to decreasing of mitochondrial oxidative stress-mediated apoptosis.
authors.affiliation: Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors.forename: Anita S Y
authors.initials: AS
authors.lastname: Chan
authors.forename: Sindhu
authors.initials: S
authors.lastname: Saraswathy
authors.forename: Matus
authors.initials: M
authors.lastname: Rehak
authors.forename: Mari
authors.initials: M
authors.lastname: Ueki
authors.forename: Narsing A
authors.initials: NA
authors.lastname: Rao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D016022:Case-Control Studies; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D005914:Globins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008928:Mitochondria / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D000078787:Neuroglobin; D018384:Oxidative Stress / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D015427:Reperfusion Injury / Q000378:metabolism*; D012164:Retinal Diseases / Q000378:metabolism*
chemical_list: D009419:Nerve Tissue Proteins; D000078787:Neuroglobin; D005914:Globins; D053148:Caspase 3