Exposure to a PFAS mixture alters cholesterol lipoprotein subfractions and induces a foam cell-like aortic macrophage...

Per- and polyfluoroalkyl substances (PFAS) have been associated with elevated cholesterol, a clinically-relevant risk factor for atherosclerosis. Macrophages are key mediators of atherosclerosis progression through their polarization to various subsets including inflammatory macrophages and foam cells. However, studies examining impacts of PFAS on macrophages in the context of atherosclerosis are lacking. Here, we investigate the impact of PFAS mixtures on cholesterol subfractions and transcriptional profiling of aortic macrophages during early atherosclerosis. Male low density lipoprotein receptor (Ldlr) deficient mice were fed an atherogenic diet and exposed via their drinking water to a mixture of 5 PFAS (i.e., PFOA, PFOS, PFNA, PFHxS, and GenX), each at a concentration of 2 mg/L, for 7 weeks. Circulating cholesterol subfractions and subclasses were analyzed, and aortic macrophages were isolated using immuno-magnetic beads for RNA-sequencing. Total circulating cholesterol was significantly elevated by 10 % following PFAS exposure which was predominately due to a 25 % increase in intermediate-density lipoprotein (IDL). The densest subfraction of low-density lipoprotein, LDL7, also increased by 206 %. RNA sequencing of aortic macrophages revealed PFAS downregulated 389 and upregulated 593 genes; many related to lipid metabolism and foam cell development. Specifically, expression of inflammatory mediators chemokine (C-X-C motif) ligand 2 (Cxcl2) and chemokine (C-X-C motif) ligand 17 (Cxcl17) were significantly increased due to PFAS (2.4 log2 fold change and 10.4 log2 FC respectively) and levels of lipid metabolism and transport genes fatty acid binding protein 4 (Fabp4) and fatty acid synthase (Fasn) were similarly increased (3 log2 FC and 5.2 log2 FC respectively). This work provides additional mechanistic information related to PFAS-mediated acceleration of atherosclerosis.