Abstract 079: Multi-omics Analyses Identify Galectin-1 As A Potential Novel Mediator Of Heart Failure With Preserved Ejection Fraction In Mice And Humans

Abstract

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome where patients present with symptoms of volume overload despite having a normal systolic function. HFpEF is associated with elevation of inflammatory biomarkers, but the precise pathways leading to cardiac dysfunction is not known. In a deoxycorticosterone acetate (DOCA)-salt model of hypertension and HFpEF, we performed CITE-Seq analysis on total leukocytes isolated from the heart, which revealed significant differential gene expression primarily in the myeloid population. We took the top 20 genes that were differentially expressed between myeloid cells from DOCA-salt vs sham treated mice and performed a genetic analysis called PrediXcan in Vanderbilt’s DNA databank, BioVU. Of these, the gene encoding galectin 1, Lgals1 , had the lowest p-value (0.02) and highest beta coefficient (0.32) corresponding to an odds ratio for HFpEF of 1.38. The role of galectin-1 in heart failure is unknown. We hypothesized that Lgals1 exacerbates HFpEF. We found that siRNA knockdown of Lgals1 in bone marrow derived macrophages stimulated with lipoprotein saccharide and IFNγ; expressed significantly more inflammatory genes including IL-1α; (p<0.0001), IL-6 (p=0.0219), iNOS (p=0.043), and TNF-α; (p=0.0031) using a 2-way ANOVA followed by Sidak’s multiple comparison test. Next, we explored the role of Lgals1 in the pathophysiology of HFpEF using Lgals1-/- mice. Surprisingly, Lgals1-/- mice did not show a significant difference in HFpEF phenotype (blood pressure, exercise tolerance, echocardiography, heart weight, or pulmonary congestion) after DOCA-salt treatment compared to littermate Lgals1+/+ controls in either males or females (p > 0.05 using Student’s t-test, n=10-12). One hypothesis for this negative result is that Lgals1 is ubiquitously expressed, and a total body knockout may have compensatory mechanisms. We subsequently created Lgals1 floxed mice and ongoing studies will determine the effect of macrophage specific deletion of galectin-1 on HFpEF. In conclusion, while multi-omics approaches in mice and humans identify galectin-1 as a novel mediator of HFpEF, further studies are needed to determine its role as a potential therapeutic target.