AP-1 (c-Fos/c-Jun) is required for corneal epithelial spreading.
OBJECTIVE
We previously demonstrated that the AP-1 components c-fos/c-jun are up-regulated in healing rat corneal epithelium in a relatively early phase following epithelial débridement, implicating the AP-1 function in the initiation of cell movement. To explore this hypothesis, we examined the effect of lack of c-Fos and c-Jun protein expressions on the spreading of corneal epithelium and in situ in organ culture. Antisense-oligonucleotide (AS) c-fos-null mice were used for this purpose.


METHODS
A rectangular piece of corneal tissue (2 x2 mm) was obtained from each eye of recently killed adult C57BL/6 mice and was incubated for 11 h in culture medium with 8 microM c-fos AS or c-jun AS probe. Sense probes were used for negative control. A rectangular section of corneal tissue was also obtained from each eye of c-fos(-/-), c-fos(+/-) and c-fos(+/+) mice and was organ-cultured for 11 h. The length of the path of epithelial spreading on stromal cut surface (both sides) was measured in hematoxylin-eosin-stained specimens. Data were analyzed by unpaired Student's t-test.


RESULTS
Addition of c-fos AS to the medium decreased the length of epithelial spread to 40.36% of that in the control with the S probe. Addition of c-jun AS decreased the length of epithelial spreading rate to 42.71% of control with S probe. Lacking c-Fos decreased the epithelial spreading to 17.73% of control data from c-fos(+/-) and c-fos(+/+) mice.


CONCLUSIONS
AP-1 (c-Fos/c-Jun) is required for the corneal epithelial spreading.
Department of Ophthalmology, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-0012, Japan. yokada@wakayama-med.ac.jp
Yuka
Y
Okada
Shizuya
S
Saika
Kumi
K
Shirai
Natsuko
N
Hashizume
Takeshi
T
Miyamoto
Osamu
O
Yamanaka
Yoshitaka
Y
Ohnishi
Masayasu
M
Miyajima
Emiko
E
Senba
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D003470:Culture Media; D019573:Epithelium, Corneal / Q000166:cytology*; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009924:Organ Culture Techniques; D016760:Proto-Oncogene Proteins c-fos / Q000502:physiology*; D016755:Proto-Oncogene Proteins c-jun / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000502:physiology*
D003470:Culture Media; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1