Genome-wide approach to identify novel candidate genes for beta blocker response in heart failure using an experimental model.

BACKGROUND We explored use of a canine model of heart failure (HF) for pharmacogenomic discovery, specifically analyzing response to beta blockers (BB). METHODS Dogs with HF that received BB (n=39) underwent genome-wide genotyping to test the association with changes in left ventricular (LV) volume and ejection fraction after treatment. Resulting candidate genes underwent RNA quantification in cardiac tissue from normal (n=5), placebo-HF (n=5), and BB-HF (n=7) dogs. RESULTS Three markers met whole-genome significance for association with improved LV end-systolic volume after BB therapy (each p<5 x 10(-7)). RNA quantification of three candidate genes near these markers -- GUCA1B, RRAGD, and MRPS10 -- revealed that gene expression levels in BB-HF dogs were between that of placebo-HF dogs and normal dogs. CONCLUSION Genome-wide pharmacogenomic screening in a canine model of HF suggests 3 novel BB response candidate loci. This approach is adaptable to discovering mechanisms of action for other drug therapies, and may be a useful strategy for identifying candidate genes for drug response in the pre-clinical setting.