Overexpression of cytochrome P450 4F2 in mice increases 20-hydroxyeicosatetraenoic acid production and arterial blood pressure

Abstract

Cytochrome P450 4F2 (CYP4F2) activity is thought to be a factor in the pathogenesis of hypertension through its bioactive metabolite 20-hydroxyeicosatetraenoic acid (20-HETE). We previously found that a gain-in-function CYP4F2 variant in a Chinese cohort was associated with elevated urinary 20-HETE and hypertension. To further explore this association we generated a transgenic mouse model expressing CYP4F2 driven by a modified mouse kidney androgen-regulated protein promoter. This heterologous promoter regulated the expression of luciferase and his-tagged CYP4F2 in transfected HEK 293 cells. In the kidney of transgenic mice, CYP4F2 was localized to renal proximal tubule epithelia and was expressed at a higher level than in control mice, leading to increased urinary 20-HETE excretion. Assessment of CYP4F2 activity by an arachidonic acid hydroxylation assay showed that 20-HETE production was significantly higher in kidney microsomes of transgenic mice compared to control mice, as was their systolic blood pressure. There was a positive correlation of blood pressure with urinary 20-HETE levels. Our results show that increased expression of CYP4F2 in mice enhanced 20-HETE production and elevated blood pressure.

Alteration of epoxyeicosatrienoic acids in the liver and kidney of cytochrome P450 4F2 transgenic mice

“…The hepatic and renal microsomes were prepared according to the method described previously (12). The conversion of AA was assessed in a reaction mixture of 100 mM potassium phosphate buffer (pH 7.4) containing 3.3 mM MgCl 2 , 80 µM AA (Cayman Chemical Company), 1 mM NADPH (Roche Applied Science, Basel, Switzerland) and 0.6 µg/µl mouse renal microsomes.…”

“…CYP4F2 transgenic mice from the FVB/N strain were generated and characterized as previously described (12). The mice were fed with standard mouse chow and water ad libitum, and bred in a 12:12 h light-dark cycle system at 23˚C.…”

Evaluation of CMV and KAP promoters for driving the expression of human CYP4F2 in transgenic mice

“…The other is anti-hypertension caused by inhibition of sodium reabsorption (6,7). We have previously elucidated the prohypertensive action of 20-HETE derived from CYP4F2 in the human population and in a transgenic mouse model (8,9). We initially identified that a functional haplotype of CYP4F2 with increased transcriptional activity is associated with elevated urinary 20-HETE and hypertension in the Chinese population (8).…”

“…We initially identified that a functional haplotype of CYP4F2 with increased transcriptional activity is associated with elevated urinary 20-HETE and hypertension in the Chinese population (8). Then, we successfully generated CYP4F2 transgenic mice of the FVB/N strain with the kidney androgen-regulated protein (KAP) promoter (KAP-CYP4F2), and documented that the preferential renal overexpression of CYP4F2 enhances 20-HETE production and elevates systolic blood pressure (SBP) (9). Nevertheless, the following problems should be further addressed: i) whether or not the FVB/N genetic background is involved in the phenotype of the transgenic mice and ii) assessment of the phenotype of transgenic mice with strong CYP4F2 overexpression in multiple tissues and organs.…”

“…The extent of 20-HETE production is possibly related to its prohypertension. Substantiating this possibility, renal overproduction of 20-HETE in mice (9,11) and rats (12)(13)(14) has been associated with the development of hypertension. Female mice, which have very low renal 20-HETE production, are more resistant to angiotensin II-induced hypertension (15).…”