Upregulation of P-selectin and intercellular adhesion molecule-1 after retinal ischemia-reperfusion injury.
OBJECTIVE
Vascular endothelial cells and leukocytes express several inflammatory adhesion receptors, such as selectins and cell adhesion molecules, after retinal ischemia. They mediate the transmigration process of leukocytes. For further understanding of the role of leukocytes after retinal ischemia-reperfusion injury, the responses of the leukocyte-endothelial cell adhesion molecules P-selectin and intercellular adhesion molecule (ICAM)-1 during retinal ischemia and reperfusion were examined.


METHODS
Male pigmented rats were subjected to retinal ischemia by a 1-hour ligation of the optic nerve followed by reperfusion. Gene and protein expression of P-selectin and ICAM-1 were studied at 0.5, 1, 6, 12, and 24 hours after the onset of reperfusion with semiquantitative polymerase chain reaction and Western blot analysis. Immunohistochemical methods were used to detect specific lesions expressing ICAM-1.


RESULTS
Significant upregulation of P-selectin and ICAM-1 mRNA (at 6, 12, and 24 hours of reperfusion) were observed, with the expression peaks of both P-selectin and ICAM-1 mRNA occurring at 12 hours after reperfusion. P-selectin protein gradually increased and reached a maximum 6 hours after reperfusion, whereas ICAM-1 protein increased until 24 hours after reperfusion. Immunostaining with ICAM-1 antibodies was positive in endothelial cells after ischemia-reperfusion injury.


CONCLUSIONS
Retinal ischemia-reperfusion stimulates P-selectin and ICAM-1 expression. Endothelial ICAM-1 expression in retinal vessels was observed. Upregulation of P-selectin and ICAM-1, which contribute to leukocyte rolling and adhesion, were observed after retinal ischemia.
Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. atoda@med.nagoya-cu.ac.jp
Akiko
A
Nishiwaki
Takashi
T
Ueda
Shinya
S
Ugawa
Shoichi
S
Shimada
Yuichiro
Y
Ogura
D000818:Animals; D015153:Blotting, Western; D004730:Endothelium, Vascular / Q000502:physiology; D019084:Fluorescent Antibody Technique, Indirect; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D007962:Leukocytes / Q000502:physiology; D008297:Male; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D015427:Reperfusion Injury / Q000378:metabolism* / Q000473:pathology; D012171:Retinal Vessels / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D019007:P-Selectin; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1