GSE211166
Immune profiling of murine cardiac leukocytes identifies Trem2 as a novel mediator of hypertensive heart failure
Heart failure with preserved ejection fraction (HFpEF) is characterized by diastolic dysfunction, microvascular dysfunction and myocardial fibrosis with recent evidence implicating the immune system in orchestrating cardiac remodeling. Here, we show the mouse model of deoxycorticosterone acetate (DOCA)-salt hypertension induces key elements of HFpEF, including diastolic dysfunction, exercise intolerance, and pulmonary congestion in the setting of preserved ejection fraction. CITE-Seq analysis of cardiac immune cells reveals an altered abundance and/or transcriptional signature in multiple cell types, most notably cardiac macrophages. The DOCA-salt model results in differential expression of several known and novel genes in cardiac macrophages, including upregulation of Trem2, which was also recently implicated in obesity and atherosclerosis. The role of macrophage Trem2 in cardiac remodeling, however, is unknown. We found that mice with genetic deletion of Trem2 exhibit increased cardiac hypertrophy and decreased cardiac capillary density after DOCA-salt treatment compared to wild-type controls, and Trem2-deficient macrophages have impaired expression of pro-angiogenic gene programs. Furthermore, we found that plasma levels of soluble TREM2 are elevated in human heart failure. Together, our data suggest a novel cardioprotective role for macrophage Trem2 in cardiac remodeling and heart failure and provide an atlas for the identification of additional targets that can lead to improved diagnostic and therapeutic strategies for HFpEF. Overall design: Cardiac immune cells were isolated by mechanical and enzymatic digestion (Liberase TM), enriched with microbeads to CD45, stained with hashtags and extracellular antibodies, flow sorted on live single immune cells and loaded onto the 10X controller for single cell sequencing.