Overexpression of COX-2, Prostaglandin E synthase-1 and prostaglandin E receptors in blood mononuclear cells and plaque of patients with carotid atherosclerosis: regulation by nuclear factor-kappaB.
OBJECTIVE
Prostaglandin E2 (PGE(2), a product of the cyclooxygenase 2 (COX-2) and membrane-associated Prostaglandin E Synthase (mPGES-1) pathway, has been implicated in the instability of atherosclerotic plaques. We have studied COX-2, mPGES-1 and PGE2 receptors (EPs) expression in peripheral blood mononuclear cells (PBMC) and atherosclerotic plaques of 29 patients with carotid stenosis as well as the effect of different nuclear factor-kappaB (NF-kappaB) inhibitors on COX-2, mPGES-1 and EPs expression in cultured monocytic cells (THP-1).


METHODS
COX-2, mPGES-1 and EP expression was analyzed by RT-PCR (PBMC), immunohistochemistry (plaques) and Western blot (THP-1). PGE2 levels were determined by ELISA (plasma and cell supernatants).


RESULTS
In relation to healthy controls, COX-2, mPGES-1 and EP-3/EP-4 mRNA expression was increased in PBMC from patients. In the inflammatory region of atherosclerotic plaques, an increase of COX-2, mPGES-1 and EPs expression was also observed. Activated NF-kappaB and COX-2, mPGES-1 and EPs proteins were colocalized in the plaque's cells. In cytokine-treated cultured THP-1, the NF-kappaB inhibitors parthenolide, Bay 11-7082 and PDTC reduced COX-2, mPGES-1 and EP-1/EP-3/EP-4 expression as well as PGE2 levels. By employing specific agonists and antagonists, we noted that the cytokine- and PGE2-induced metalloproteinase 9 (MMP-9) expression and activity occurs through EP-1/EP-3/EP-4, an effect downregulated by NF-kappaB inhibitors.


CONCLUSIONS
Patients with carotid atherosclerosis depict an overexpression of COX-2, mPGES-1 and EPs simultaneously in the PBMC as well as in the vulnerable region of plaques. The studies in cultured monocytic cells suggest that NF-kappaB inhibitors and/or EPs antagonists could represent a novel therapeutic approach to the treatment of plaque instability and rupture.
Gómez-Hernández
Almudena
A
Vascular Research Laboratory, Fundación Jiménez Díaz, Avda Reyes Católicos 2, 28040 Madrid, Spain.
Martín-Ventura
Jose Luis
JL
Sánchez-Galán
Eva
E
Vidal
Cristina
C
Ortego
Mónica
M
Blanco-Colio
Luis Miguel
LM
Ortega
Luis
L
Tuñón
José
J
Egido
Jesús
J
D000368:Aged; D002340:Carotid Artery Diseases / Q000097:blood / Q000378:metabolism* / Q000473:pathology*; D016022:Case-Control Studies; D002460:Cell Line; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism*; D000071876:Prostaglandin-E Synthases; D018078:Receptors, Prostaglandin E / Q000378:metabolism*
D016328:NF-kappa B; D018078:Receptors, Prostaglandin E; D051546:Cyclooxygenase 2; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; D000071876:Prostaglandin-E Synthases