Cell-type specific secretome profiling reveals targets of liver-heart interorgan crosstalk in HFpEF and semaglutide treatment

Abstract Background Heart failure with preserved ejection fraction (HFpEF) is a multisystemic syndrome, accounting for the majority of heart failure cases worldwide. Up to 50% of patients diagnosed with HFpEF also suffer from "metabolic dysfunction-associated fatty liver disease" (MAFLD). The shared metabolic dysfunction in HFpEF and MAFLD triggered growing research interest in the liver-heart crosstalk. Purpose This study aims to elucidate the organ interactions between liver and heart in cardiometabolic HFpEF in vivo. Methods Here, we report a hepatocyte specific secretome profiling approach in a mouse model of HFpEF, allowing direct labeling, identification and dynamic tracking of secreted proteins on a cell-type specific level. HFpEF was induced by the "two-hit model" in C57BL/6N male mice. 10 weeks after induction of HFpEF, we implemented a cardiometabolic rescue strategy with the glucagon-like peptide 1 receptor agonist semaglutide. Quantification of the hepatocyte "secretome" was performed after delivering an engineered biotinylation enzyme via adeno-associated virus (AAV) transduction under the control of the hepatocyte-selective thyroxine binding protein (Tbg) promoter. Results Following biotin administration and blood plasma streptavidin purification, we could detect 244 significantly enriched hepatocyte-derived plasma proteins trough LC-MS analysis. HFpEF lead to the upregulation of 17 hepatocyte derived plasma proteins compared to chow, while 20 were downregulated. "Positive regulation of immune response" and "cytokine-mediated signaling pathway" were among the most frequent and significantly enriched biological processes involved in response to HFpEF. On top of that, following the removal of blood contaminants, streptavidin pulldown revealed the presence of liver-derived proteins in cardiac, lung, adipose and muscle tissue during HFpEF. Treatment with semaglutid not only significantly improved cardiac diastolic dysfunction and resolved pathological features of steatohepatitis, but also resulted in a deregulated secretomic liver profile. We validated differential expression levels of identified hits in human patient cohorts, including cell-surface receptors of the liver specifically released to the blood in response to metabolic stress. Conclusions Our approach allows the longitudinal detection of secretomes on a cell-type specific resolution and harbors the potential to track origin and destination of secreted proteins in vivo, thereby offering valuable new insights to understand interorgan communication in HFpEF. We could reveal previously undescribed mediators of potential liver-heart crosstalk and likely translational relevance, that warrant further mechanistic studies to pave the way for target-oriented future therapies.