Cyclooxygenase 2 expression in rat corneas after ethanol exposure.
OBJECTIVE
To evaluate the effects of ethanol exposure of the cornea on inflammation in corneal epithelium.


METHODS
Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan.


METHODS
One cornea of Wistar rats (n = 60) was exposed to ethanol 20% for 30 seconds. The animals were killed 0.5, 1.0, 1.5, 2.0, 6.0, 12.0, 24.0, 48.0, or 72.0 hours or 7 days after treatment. The paraffin section or cryosection of the treated eyes was processed for histology; immunohistochemistry for cyclooxygenase 2 (COX2); p65 subunit of nuclear factor kappa B (NF-kappaB), which is the major transcription factor involved in COX2 expression; phospho-IkappaB; or in situ hybridization for COX2 mRNA.


RESULTS
In the uninjured corneas, faint immunoreactivity for COX2 was detected in the basal cells of the corneal epithelium, but not in other cell layers. Cyclooxygenase 2 mRNA was not observed in the injured epithelium; it was expressed 2 hours after ethanol exposure, but not 3 hours or later after treatment. The COX2 protein was detected in the corneal epithelium throughout the epithelial layers from 3 to 72 hours, but not at 7 days. The p65 of NF-kappaB translocated to the nuclei of corneal epithelium 3 to 24 hours after treatment but was not seen in the nuclei 48 hours after treatment. Phospho-I kappaB was detected in corneal epithelium 6 hours after treatment, but not 12 hours or later.


CONCLUSIONS
Ethanol exposure activated NF-kappaB and upregulated COX2 expression, which may cause inflammation in corneal tissue.
Miyamoto
Takeshi
T
Department of Ophthalmology, Wakayama Medical University, Kimiidera, Wakayama-City, Wakayama, Japan. tmiyam@wakayama-med.ac.jp
Saika
Shizuya
S
Ueyama
Takashi
T
Okada
Yuka
Y
Shirai
Kumi
K
Sumioka
Takayoshi
T
Fujita
Kyoko
K
Ishiwaka
Nobuyuki
N
Ohnishi
Yoshitaka
Y
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D003315:Cornea / Q000187:drug effects* / Q000201:enzymology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology*; D020672:I-kappa B Proteins / Q000378:metabolism; D007124:Immunoenzyme Techniques; D017403:In Situ Hybridization; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D051996:Transcription Factor RelA / Q000378:metabolism; D015854:Up-Regulation
D000891:Anti-Infective Agents, Local; D020672:I-kappa B Proteins; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D000431:Ethanol; D051546:Cyclooxygenase 2