Abstract 089: A Genetic Variant of Human Aldosterone Synthase Gene Causes Salt-Dependent High Blood Pressure in Transgenic Mice

Aldosterone, synthesized by the enzyme CYP11B2, induces positive sodium-balance and predisposes to hypertension. Various investigators, using genomic DNA analyses, have linked -344T polymorphism in the hCYP11B2 gene to human hypertension. We have identified three SNPs, in linkage disequilibrium, in the hCYP11B2 gene: T/A at -663, T/C at -470 and C/T at -344. Variants ACT occur together and form the haplotype I (Hap I) while variants TTC constitute haplotype II (Hap II). We hypothesize that these SNPs, when present together, will lead to haplotype-dependent transcription of the hCYP11B2 gene, differentially increase aldosterone and affect blood pressure. To this end, novel transgenic (TG) mice with the hCYP11B2 gene, targeted to the mHPRT locus, with either haplotype II or I variant are used in the study. ChIP assay, using anti-RNA pol II antibody, shows increased Pol II binding to the chromatin from Hap I TG mice in adrenal (2.8 fold higher, p