Evaluation of retinal degeneration in P27KIP1 null mouse.
OBJECTIVE
p27kip1 is well-known as a cell cycle inhibitor and also plays an important role for cell differentiation. We hypothesized that if we caused retinal degeneration in a p27(-/-) mouse, then the appropriate method of restoration may be different from that of wild mice and therefore suggest a therapeutic methodology for retinal regeneration.


METHODS
Histological and electrophysiological (ERG) examination was performed on p27(-/-) mice retina. We injected N-methy-N-nitrosourea (MNU) to induce retinal degeneration. BrdU was used to identify the dividing cells in the retina.


RESULTS
Thicker retina were observed in the p27(-/-) mice when compared to those of the p27(-/+) mice or wild type mice. Almost all retinal layers were thick and optic nerves were also enlarged. A statistically significant decrease of a and b waves amplitudes of ERG was observed in p27(-/-) mice when compared to those of the other mice. BrdU and nestin positive cells were present at the outer nuclear layer with no difference between p27(-/-) and wild type mice after MNU injection.


CONCLUSIONS
p27(-/-) mice showed thicker retina and less retinal function than those of other mice. The MNU-induced retinal degeneration in p27(-/-) mice closely resembled the reaction of the other mice with no retinal regeneration observed in our experimental condition.
Tokita-Ishikawa
Yumi
Y
Center for Translational and Advanced Animal Research, Miyagi, Sendai, 980-8574, Japan.
Wakusawa
Ryosuke
R
Abe
Toshiaki
T
D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000172:deficiency* / Q000378:metabolism; D004596:Electroretinography; D005654:Fundus Oculi; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D012162:Retinal Degeneration / Q000473:pathology* / Q000503:physiopathology
D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D050760:Cyclin-Dependent Kinase Inhibitor p27; D001973:Bromodeoxyuridine