Activation of NF kappa B and expression of ICAM-1 in ischemic-reperfused canine myocardium.
Although redox-sensitive transcription factors, including nuclear factor kappa B (NF kappa B) and activator protein-1 (AP-1), have been shown to induce intercellular adhesion molecule-1 (ICAM-1) gene transcription in isolated cells, little is known about their involvement in the regulation of the ICAM-1 gene in vivo during ischemia-reperfusion. Anesthetized closed-chest dogs underwent 90 min coronary artery occlusion, followed by reperfusion for 0, 15, 30, 60, 180, or 360 min. Blood flow (fluorescent or radioactive microspheres), ICAM-1 protein expression (immunohistochemistry), ICAM-1 gene activation (Northern blotting), and nuclear DNA-binding activity of NF kappa B and AP-1 (electrophoretic mobility shift assays) were assessed in myocardial tissue samples. ICAM-1 protein was expressed constitutively on vascular endothelium, but expression levels decreased markedly during ischemia. Within 15 min reperfusion, endothelial ICAM-1 protein increased, associated with a rapid appearance of ICAM-1 mRNA. Activation of both NF kappa B and AP-1 occurred following ischemia-reperfusion, but did not coincide temporally with early post-reperfusion ICAM-1 gene induction. NF kappa B was activated during ischemia, when ICAM-1 mRNA was undetectable, and did not increase further until 60 min reperfusion, well after the increase in ICAM-1 mRNA had begun. Similarly, AP-1 did not increase until 60 min reperfusion. In non-ischemic myocardium, NF kappa B and AP-1 were both activated, but ICAM-1 mRNA did not appear until 6 h later. By immunohistology, NF kappa B (p65 subunit) and the c-Fos subunit of AP-1 were localized primarily in vascular endothelium. Reperfusion of ischemic myocardium is associated with very rapid ICAM-1 gene induction in the context of prior NF kappa B activation, without new activation of NF kappa B. In non-ischemic myocardium, ICAM-1 transcription begins hours after NF kappa B is activated. These findings support a role for NF kappa B in ICAM-1 induction in vivo, but suggest that other processes, such as oxygen-radical generation, may combine with NF kappa B to trigger an accelerated transcription of ICAM-1 following ischemia-reperfusion.
Sun
B
B
Division of Cardiology, The Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
Fan
H
H
Honda
T
T
Fujimaki
R
R
Lafond-Walker
A
A
Masui
Y
Y
Lowenstein
C J
CJ
Becker
L C
LC
D000818:Animals; D001160:Arterioles / Q000378:metabolism / Q000473:pathology; D015152:Blotting, Northern; D002196:Capillaries / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000378:metabolism; D004285:Dogs; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D007249:Inflammation; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D017202:Myocardial Ischemia / Q000235:genetics* / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000235:genetics* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D009928:Organ Specificity; D010084:Oxidation-Reduction; D021122:Protein Subunits; D012333:RNA, Messenger / Q000096:biosynthesis; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation
D016328:NF-kappa B; D021122:Protein Subunits; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D018799:Intercellular Adhesion Molecule-1