Enhanced expression of B7-1, B7-2, and intercellular adhesion molecule 1 in sinusoidal endothelial cells by warm ischemia/reperfusion injury in rat liver.
To elucidate a role of costimulatory molecule and cell adhesion molecule in hepatic ischemia/reperfusion injury, we examined an alteration in B7-1 (CD80), B7-2 (CD86), and intercellular adhesion molecule 1 (ICAM-1; CD54) expression in the rat liver after warm ischemia/reperfusion injury. To induce hepatic warm ischemia in a rat model, both portal vein and hepatic artery entering the left-lateral and median lobes were occluded by clamping for 30 minutes or 60 minutes, and then reperfused for 24 hours. B7-1, B7-2, and ICAM-1 expressions in the liver were analyzed by immunofluorescence staining and real-time reverse transcription polymerase chain reaction (RT-PCR). Although B7-1 and B7-2 expressions were at very low levels in the liver tissues from normal or sham-operated control rats, both B7-1 and B7-2 expressions were enhanced at protein and messenger RNA (mRNA) levels in the affected, left lobes after warm ischemia/reperfusion. ICAM-1 protein and mRNA were constitutively expressed in the liver of normal and sham-operated control rats, and further up-regulated after warm ischemia/reperfusion. Localization of increased B7-1, B7-2, and ICAM-1 proteins, as well as von Willebrand factor as a marker protein for endothelial cells, was confined by immunofluorescence staining to sinusoidal endothelial cells in hepatic lobules. Data from quantitative real-time RT-PCR analysis revealed that B7-1 and B7-2 mRNA levels were elevated in hepatic lobes after warm ischemia/reperfusion (5.13- and 52.9-fold increase, respectively), whereas ICAM-1 mRNA expression was rather constitutive but further enhanced by warm ischemia/reperfusion (4.24-fold increase). These results suggest that hepatic sinusoidal endothelial cells play a pivotal role as antigen-presenting cells by expressing B7-1 and B7-2 in warm hepatic ischemia/reperfusion injury, and that B7-1 and/or B7-2 might be the primary target to prevent early rejection and inflammatory reactions after hepatic ischemia/reperfusion injury associated with liver transplantation.
Kojima
N
N
Departments of Anatomy and Urology, Akita University School of Medicine, Akita, Japan.
Sato
M
M
Suzuki
A
A
Sato
T
T
Satoh
S
S
Kato
T
T
Senoo
H
H
D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis*; D018122:B7-1 Antigen / Q000096:biosynthesis*; D051940:B7-2 Antigen; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D007511:Ischemia / Q000378:metabolism*; D008099:Liver / Q000098:blood supply*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497966:Cd86 protein, rat; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1