angiotensinogen and 11-12-epoxy-5-8-14-eicosatrienoic-acid

Cytochrome P450 (CYP)-dependent arachidonic acid (AA) metabolites are involved in the regulation of renal vascular tone and salt excretion. The epoxygenation product 11,12-epoxyeicosatrienoic acid (EET) is anti-inflammatory and inhibits nuclear factor-kappa B activation. We tested the hypothesis that the peroxisome proliferator-activated receptor-alpha-activator fenofibrate (Feno) induces CYP isoforms, AA hydroxylation, and epoxygenation activity, and protects against inflammatory organ damage. Double-transgenic rats (dTGRs) overexpressing human renin and angiotensinogen genes were treated with Feno. Feno normalized blood pressure, albuminuria, reduced nuclear factor-kappa B activity, and renal leukocyte infiltration. Renal epoxygenase activity was lower in dTGRs compared to nontransgenic rats. Feno strongly induced renal CYP2C23 protein and AA-epoxygenase activity under pathological and nonpathological conditions. In both cases, CYP2C23 was the major isoform responsible for 11,12-EET formation. Moreover, we describe a novel CYP2C23-dependent pathway leading to hydroxy-EETs (HEETs), which may serve as endogenous peroxisome proliferator-activated receptor-alpha activators. The capacity to produce HEETs via CYP2C23-dependent epoxygenation of 20-HETE and CYP4A-dependent hydroxylation of EETs was reduced in dTGR kidneys and induced by Feno. These results demonstrate that Feno protects against angiotensin II-induced renal damage and acts as inducer of CYP2C23-mediated epoxygenase activities. We propose that CYP-dependent EET/HEET production may serve as an anti-inflammatory control mechanism.

Topics: 8,11,14-Eicosatrienoic Acid; Angiotensin II; Angiotensinogen; Animals; Animals, Genetically Modified; Arachidonic Acid; Blotting, Western; Chromatography, Liquid; Cytochrome P-450 CYP2J2; Cytochrome P-450 Enzyme System; Fenofibrate; Humans; Hypertension; Hypolipidemic Agents; Immunohistochemistry; Kidney; Kidney Diseases; Mass Spectrometry; NF-kappa B; Polymerase Chain Reaction; Rats; Receptors, Cytoplasmic and Nuclear; Renin; Transcription Factors; Vasoconstrictor Agents