Abstract
Cytochrome P450 (P450)-derived epoxyeicosatrienoic acids (EETs) exert well recognized vasodilatory, diuretic, and tubular fluid-electrolyte transport actions that are predictive of a hypotensive effect. The study sought to determine the improvement of hypertension and cardiac function by overexpressing P450 epoxygenases in vivo. Long-term expression of CYP102 F87V or CYP2J2 in spontaneously hypertensive rats (SHR) was mediated by using a type 8 recombinant adeno-associated virus (rAAV8) vector. Hemodynamics was measured by a Millar Instruments, Inc. (Houston, TX) microtransducer catheter, and atrial natriuretic peptide (ANP) mRNA levels were tested by real-time polymerase chain reaction. Results showed that urinary excretion of 14,15-EET was increased at 2 and 6 months after injection with rAAV-CYP102 F87V and rAAV-CYP2J2 compared with controls (p < 0.05). During the course of the 6-month study, systolic blood pressure significantly decreased in P450 epoxygenase-treated rats, but the CYP2J2-specific inhibitor C26 blocked rAAV-CYP2J2-induced hypotension and the increase in EET production. Cardiac output was improved by P450 epoxygenase expression at 6 months (p < 0.05). Furthermore, cardiac collagen content was reduced in P450 epoxygenase-treated rats. ANP mRNA levels were up-regulated 6- to 14-fold in the myocardium, and ANP expression was significantly increased in both myocardium and plasma in P450 epoxygenase-treated rats. However, epidermal growth factor (EGF) receptor antagonist 4-(3′-chloroanilino)-6,7-dimethoxy-quinazoline (AG-1478) significantly attenuated the increase in the EET-induced expression of ANP in vitro. These data indicate that overexpression of P450 epoxygenases attenuates the development of hypertension and improves cardiac function in SHR, and that these effects may be mediated, at least in part, by ANP via activating EGF receptor.
Footnotes
This work was supported in part by the National Natural Science Foundation of China [Grants 30430320, 30930039]; National “973” projects [Grant 2007CB512004]; International Collaboration and Wuhan City projects; and in part by the Intramural Research Program of the National Institutes of Health National Institute of Environmental Health Sciences.
Article, publication date, and citation information can be found at http://jpet.aspetjournals.org.
doi:10.1124/jpet.110.167510.
↵ The online version of this article (available at http://jpet.aspetjournals.org) contains supplemental material.
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ABBREVIATIONS:
- P450
- cytochrome P450
- EET
- epoxyeicosatrienoic acid
- eNOS
- endothelial nitric-oxide synthase
- sEH
- soluble epoxide hydrolase
- DHET
- dihydroxyeicosatrienoic acid
- rAAV
- recombinant adeno-associated viral vector
- SHR
- spontaneously hypertensive rat
- ANP
- atrial natriuretic peptide
- GFP
- green fluorescent protein
- NE
- norepinephrine
- ACh
- acetylcholine
- ELISA
- enzyme-linked immunosorbent assay
- RT-PCR
- reverse transcriptase-polymerase chain reaction
- MMP
- matrix metalloproteinase
- AG-1478
- 4-(3′-chloroanilino)-6,7-dimethoxy-quinazoline
- EGFR
- epithelial growth factor receptor
- CRM
- cross-reacting material
- HB-EGF
- heparin-binding epidermal growth factor-like growth factor
- GW9662
- 2-chloro-5-nitro-N-phenylbenzamide
- PPAR-γ
- peroxisome proliferator-activated receptor-γ
- CO
- cardiac output
- Ea
- arterial elastance
- CRE
- cAMP-response element.
- Received February 22, 2010.
- Accepted May 24, 2010.
- U.S. Government work not protected by U.S. copyright
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