Exacerbation of retinal degeneration in the absence of alpha crystallins in an in vivo model of chemically induced hypoxia

Exp Eye Res. 2008 Feb;86(2):355-65. doi: 10.1016/j.exer.2007.11.007. Epub 2007 Nov 17.


This study evaluated the role of crystallins in retinal degeneration induced by chemical hypoxia. Wild-type, alphaA-crystallin (-/-), and alphaB-crystallin (-/-) mice received intravitreal injection of 12 nmol (low dose), 33 nmol (intermediate dose) or 60 nmol (high dose) cobalt chloride (CoCl(2)). Hematoxylin and eosin and TdT-mediated dUTP nick-end labeling (TUNEL) stains were performed after 24 h, 96 h, and 1 week post-injection, while immunofluorescent stains for alphaA- and alphaB-crystallin were performed 1 week post-injection. The in vitro effects of CoCl(2) on alphaB-crystallin expression in ARPE-19 cells were determined by real time RT-PCR, Western blot, and confocal microscopy and studies evaluating subcellular distribution of alphaB-crystallin in the mitochondria and cytosol were also performed. Histologic studies revealed progressive retinal degeneration with CoCl(2) injection in wild-type mice. Retinas of CoCl(2) injected mice showed transient increased expression of HIF-1alpha which was maximal 24h after injection. Intermediate-dose CoCl(2) injection was associated with increased retinal immunofluorescence for both alphaA- and alphaB-crystallin; however, after high-dose injection, increased retinal degeneration was associated with decreased levels of crystallin expression. Injection of CoCl(2) at either intermediate or high dose in alphaA-crystallin (-/-) and alphaB-crystallin (-/-) mice resulted in much more severe retinal degeneration compared to wild-type eyes. A decrease in ARPE-19 total and cytosolic alphaB-crystallin expression with increasing CoCl(2) treatment and an increase in mitochondrial alphaB-crystallin were found. We conclude that lack of alpha-crystallins accentuates retinal degeneration in chemically induced hypoxia in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Cells, Cultured
  • Disease Models, Animal*
  • Disease Progression
  • Mice
  • Mice, Knockout
  • Mitochondria / metabolism
  • Pigment Epithelium of Eye / metabolism
  • Pigment Epithelium of Eye / pathology
  • Retinal Degeneration / chemically induced
  • Retinal Degeneration / metabolism*
  • Retinal Degeneration / pathology
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • alpha-Crystallin B Chain / genetics
  • alpha-Crystallin B Chain / metabolism
  • alpha-Crystallins / deficiency*
  • alpha-Crystallins / genetics
  • alpha-Crystallins / physiology


  • alpha-Crystallin B Chain
  • alpha-Crystallins