Two-hit mouse model of heart failure with preserved ejection fraction combining diet-induced obesity and renin-mediated hypertension

Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic interventions is hampered by the lack of robust pre-clinical mouse models of human HFpEF. We have developed a novel “2-hit” mouse model, which combines obesity and insulin resistance with chronic pressure overload to recapitulate clinical features of HFpEF. C57Bl6/NJ mice fed a high fat diet for at least 10 weeks were administered an AAV8-driven vector resulting in constitutive overexpression of mouse Renin1d. Control mice, HFD only, Renin only and HFD-Renin (aka “HFpEF”) littermates underwent a battery of cardiac and extracardiac phenotyping. HFD-Renin mice demonstrated obesity and insulin resistance, a 2-3-fold increase in circulating renin levels and resulted in 30-40% increase in LVH hypertrophy, preserved systolic function, and diastolic dysfunction indicated by altered E/e’, IVRT, and strain measurements; increased left atrial mass; elevated natriuretic peptides; and exercise intolerance. The transcriptomic and metabolomic signature of HFpEF indicates upregulation of fibrotic pathways and downregulation of metabolic pathways, in particular branched chain amino acid catabolism, similar to human HFpEF data. Treatment of these mice with the sodium-glucose cotransporter 2 inhibitor empagliflozin, a powerful but incompletely understood HFpEF therapy, showed improvement in exercise tolerance, left heart enlargement, and insulin homeostasis. The HFD-Renin mouse model recapitulates many critical features of human HFpEF and allows for dissection of how individual pathogenic drivers contribute to cardiac and peripheral metabolic changes. Multiple HFpEF models will also allow for orthogonal studies and increase validity in pre-clinical research efforts. To determine the effect of HFpEF on transcriptional changes in heart tissue, control mice were compared to HFpEF (e.g. HFD + Renin) or constituent (e.g. HFD alone or Renin alone) cohorts. Male C57BL/6NJ mice (Jackson Laboratory, Stock 005304) age 8-10 weeks old, were randomized to chow or 60%kcal HFD (D12492i, Research Diets) for 10 weeks. Mice were again randomized to receive AAV-Renin or null vector (control). Samples were collected at 6 weeks post-retroorbital injection. Mice (n=4-6) were euthanized with pentobarbital, and heart tissue was freeze clamped, prior to processing.