title: αB-crystallin/sHSP protects cytochrome c and mitochondrial function against oxidative stress in lens and retinal cells.
abstract: BACKGROUND
  αB-crystallin/sHSP protects cells against oxidative stress damage. Here, we mechanistically examined its ability to preserve mitochondrial function in lens and retinal cells and protect cytochrome c under oxidative stress conditions.
  
  
  METHODS
  αB-crystallin/sHSP was localized in human lens (HLE-B3) and retinal (ARPE-19) cells. αB-crystallin/sHSP was stably over-expressed and its ability to preserve mitochondrial membrane potential under oxidative stress conditions was monitored. Interactions between αB-crystallin/sHSP and cytochrome c were examined by fluorescent resonance energy transfer (FRET) and by co-immune precipitation. The ability of αB-crystallin/sHSP to protect cytochrome c against methionine-80 oxidation was monitored.
  
  
  RESULTS
  αB-crystallin/sHSP is present in the mitochondria of lens and retinal cells and is translocated to the mitochondria under oxidative conditions. αB-crystallin/sHSP specifically interacts with cytochrome c in vitro and in vivo and its overexpression preserves mitochondrial membrane potential under oxidative stress conditions. αB-crystallin/sHSP directly protects cytochrome c against oxidation.
  
  
  CONCLUSIONS
  These data demonstrate that αB-crystallin/sHSP maintains lens and retinal cells under oxidative stress conditions at least in part by preserving mitochondrial function and by protecting cytochrome c against oxidation. Since oxidative stress and loss of mitochondrial function are associated with eye lens cataract and age-related macular degeneration, loss of these αB-crystallin/sHSP functions likely plays a key role in the development of these diseases. αB-crystallin/sHSP is expressed throughout the body and its ability to maintain mitochondrial function is likely important for the prevention of multiple degenerative diseases.
authors.affiliation: Biomedical Sciences Department, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: McGreal
authors.forename: Wanda Lee
authors.initials: WL
authors.lastname: Kantorow
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Chauss
authors.forename: Jianning
authors.initials: J
authors.lastname: Wei
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Brennan
authors.forename: Marc
authors.initials: M
authors.lastname: Kantorow
mesh_terms: D015153:Blotting, Western; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D007908:Lens, Crystalline / Q000166:cytology / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D038203:alpha-Crystallin B Chain / Q000378:metabolism*
chemical_list: D038203:alpha-Crystallin B Chain; D045304:Cytochromes c