Deoxycorticosterone acetate (DOCA)-salt is a common hypertension model in mice and has recently been used to study heart failure with preserved ejection fraction (HFpEF) in rats. Our goal was to validate DOCA-salt as a mouse model of HFpEF and determine how DOCA-salt alters the cardiac immunological landscape to identify novel therapeutic targets for this disease. DOCA-salt mice underwent uninephrectomy, implantion of a DOCA pellet, and supplementation of the drinking water with 1% NaCl water for three weeks. Control mice underwent a sham procedure and received normal water. Compared to control mice, DOCA-salt mice exhibited elevated systolic BP, increased heart weight to body weight ratios (5.6 vs 7.1), increased lung wet to dry weight ratios (4.4 vs 4.8) indicative of pulmonary congestion, and decreased time to exhaustion upon treadmill exercise testing (23.0 vs. 18.5 seconds). On conscious echocardiography, DOCA-salt mice exhibited a preserved ejection fraction. Invasive hemodynamic studies revealed an increased tau constant (5.7 vs 8.2) and increased end-diastolic pressures in DOCA-salt mice (1.7 vs 2.6), consistent with diastolic dysfunction. CITE-seq, a novel technique to obtain transcriptomic and surface marker expression on single cells, was performed on a total of 4,359 and 7,600 cells sorted live CD45+ leukocytes from four sham and four DOCA-salt left ventricles, respectively. Unsupervised computational analysis revealed 29 clusters of immune cells. Six clusters containing natural killer, T lymphocyte and myeloid cell populations were overrepresented and five B cell clusters were underrepresented in DOCA-salt samples. Differential expression analysis of CD11b+CD64+ cardiac macrophages revealed transcriptional changes between groups with 146 significantly upregulated and 111 downregulated genes. Gene set enrichment analysis showed upregulation of leukocyte migration, response to type I interferon, and cytokine-mediated signaling pathways in DOCA-salt macrophages. In conclusion, the DOCA-salt mouse model recapitulates key features of HFpEF including diastolic dysfunction with preserved ejection fraction, cardiac hypertrophy, and pulmonary congestion and is associated with an altered cardiac immune cell profile.
Faculty Opinions recommendation of Energetic Basis for Exercise-Induced Pulmonary Congestion in Heart Failure With Preserved Ejection Fraction.
