Abstract 691: Reduced Human Myocardial mRNA Expression of CYP2J2 in Individuals With the G-50T Promoter Polymorphism
Background: Cytochrome P450 enzyme CYP2J2 is predominantly expressed in the heart and synthesizes 11, 12-epoxyeicosatrienoic acid (11, 12-EET) which has anti-inflammatory, vasodilatory and other vasoprotective effects. The promoter polymorphism G-50T of CYP2J2 results in reduced gene expression in transfection studies and is associated with an increased risk of coronary artery disease. In the present study we investigated if this polymorphism is associated with a reduced CYP2J2 mRNA expression in human myocardium.
Methods: Myocardial tissue from the explanted hearts of heart transplant recipients was analyzed (n = 88). DNA was extracted for CYP2J2 genotyping. RT-PCR was performed after extraction of RNA and cardiac mRNA expression of G-50T mutants was compared with wild-type samples. Quantification was performed with Light-Cycler PCR. All samples were measured in triplicate and the results were related to GAPDH mRNA expression and to calibrated samples of CYP2J2 or GAPDH mRNA in each run, respectively.
Results: Genotyping identified 11 G-50T mutants within 88 samples (allele frequency: 6.25%). Cardiac tissue of G-50T mutants had a significantly lower relative mRNA expression (2.3 ± 0.23, mean ± SEM) compared to wild-type samples (3.7 ± 0.36, p < 0.01). The promoter polymorphism resulted in a 38 % reduction of CYP2J2 mRNA expression. These results further support the in vivo functional relevance of the G-50T mutant.
Conclusion: Reduced availability of the anti-inflammatory CYP2J2 mRNA in human myocardium is a potential explanation for the association of the G-50T mutant with coronary artery disease.