NF-kappaB activation and Fas ligand overexpression in blood and plaques of patients with carotid atherosclerosis: potential implication in plaque instability.
OBJECTIVE
Apoptosis is present in human atherosclerotic lesions. Nuclear factor-kappaB (NF-kappaB) is involved in the transcriptional regulation of the proapoptotic protein Fas ligand (FasL). We have analyzed NF-kappaB activation and FasL expression in atherosclerotic plaques and peripheral blood mononuclear cells (PBMCs) of patients with carotid stenosis.


METHODS
NF-kappaB activation and FasL and active caspase-3 expression were analyzed in 32 human carotid plaques. NF-kappaB activation and FasL mRNA were tested in PBMCs of patients and healthy volunteers. We analyzed whether the NF-kappaB inhibitor parthenolide regulates FasL expression and cytotoxicity in human T cells.


RESULTS
The inflammatory region of plaques showed an increase in NF-kappaB activation (3393+/-281 versus 1029+/-100 positive nuclei per mm(2), P<0.001) and FasL (16+/-1.4% versus 13+/-1.8%, P<0.05) and active caspase-3 (3.3+/-0.6 versus 1.5+/-0.3%, P<0.05) expression compared with the fibrous area. Activated NF-kappaB and FasL protein were colocalized in plaque cells. In PBMCs obtained from those patients the day of endarterectomy, NF-kappaB activation and FasL expression were significantly increased compared with healthy controls (1.5+/-0.1 versus 0.5+/-0.1 and 2.1+/-0.1 versus 1.2+/-0.1 arbitrary units, respectively; P<0.001). There was a significant correlation between NF-kappaB activation and FasL expression. In activated T cells, parthenolide decreased NF-kappaB activation, FasL promoter activity, and mRNA expression. Parthenolide also decreased cytotoxicity of activated Jurkat cells on FasL-sensitive cells.


CONCLUSIONS
NF-kappaB activation and FasL overexpression occur in PBMCs and atherosclerotic lesions of patients with carotid stenosis. The NF-kappaB-FasL pathway could be involved in the mechanisms underlying plaque instability in humans.
Martín-Ventura
José Luis
JL
Vascular Research Laboratory, Fundación Jiménez Díaz, Autonoma University, Madrid, Spain.
Blanco-Colio
Luis Miguel
LM
Muñoz-García
Begoña
B
Gómez-Hernández
Almudena
A
Arribas
Ana
A
Ortega
Luis
L
Tuñón
José
J
Egido
Jesús
J
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002340:Carotid Artery Diseases / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D003601:Cytotoxicity Tests, Immunologic; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D019169:Jurkat Cells; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D012717:Sesquiterpenes / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D014162:Transfection
D000894:Anti-Inflammatory Agents, Non-Steroidal; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D012333:RNA, Messenger; D012717:Sesquiterpenes; C002669:parthenolide; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases