Loss of protein kinase Cgamma in knockout mice and increased retinal sensitivity to hyperbaric oxygen.
OBJECTIVE
To determine if loss of protein kinase Cgamma (PKCgamma) results in increased structural damage to the retina by hyperbaric oxygen (HBO), a treatment used for several ocular disorders.


METHODS
Six-week-old mice were exposed in vivo to 100% HBO 3 times a week for 8 weeks. Eyes were dissected, fixed, embedded in Epon, sectioned, stained with toluidine blue O, and examined by light microscopy.


RESULTS
The thicknesses of the inner nuclear and ganglion cell layers were increased. Destruction of the outer plexiform layer was observed in the retinas of the PKCgamma-knockout mice relative to control mice. Exposure to HBO caused significant degradation of the retina in knockout mice compared with control mice. Damage to the outer segments of the photoreceptor layer and ganglion cell layer was apparent in central retinas of HBO-treated knockout mice.


CONCLUSIONS
Protein kinase Cgamma-knockout mice had increased retinal sensitivity to HBO. Results demonstrate that PKCgamma protects retinas from HBO damage.


CONCLUSIONS
Care should be taken in treating patients with HBO, particularly if they have a genetic disease, such as spinocerebellar ataxia type 14, a condition in which the PKCgamma is mutated and nonfunctional.
Department of Biochemistry, 141 Chalmers Hall, Kansas State University, Manhattan, Kansas 66506, USA.
Vladimir V
VV
Yevseyenkov
Satyabrata
S
Das
Dingbo
D
Lin
Lloyd
L
Willard
Harriet
H
Davidson
Ari
A
Sitaramayya
Frank J
FJ
Giblin
L
L
Dang
Dolores J
DJ
Takemoto
D000818:Animals; D015153:Blotting, Western; D006931:Hyperbaric Oxygenation; D051379:Mice; D018345:Mice, Knockout; D018384:Oxidative Stress; D010100:Oxygen / Q000633:toxicity*; D011493:Protein Kinase C / Q000502:physiology*; D012162:Retinal Degeneration / Q000201:enzymology* / Q000209:etiology* / Q000473:pathology; D012165:Retinal Ganglion Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D055214:Retinal Photoreceptor Cell Outer Segment / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology
C087857:protein kinase C gamma; D011493:Protein Kinase C; D010100:Oxygen