ABSTRACT: Per- and polyfluoroalkyl substances (PFASs), common environmental contaminants, can cause cardiotoxic effects particularly during fetal development. However, combined PFAS exposure, which more closely reflects real-world environmental conditions, remains poorly understood. In this study, human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were exposed to three common PFAS compounds-perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA), and perfluorodecanoic acid (PFDA), individually or in combination. Compared with single PFAS compounds, combined PFAS exposure induced synergistic cytotoxicity, significantly reducing hiPSC-CM viability after 5 or 10 days. Combined PFAS exposure for 10 days reduced mitochondrial membrane potential and content in a dose-dependent manner and caused a shift in cysteine metabolism, potentially indicative of an adaptive response to oxidative challenges. Following 14 days of exposure, combined PFASs increased vimentin, a fibroblast marker, along with reduced NK2 Homeobox 5 (NKX2.5), alpha-actinin, and cardiac troponin T (cTnT), key markers of cardiomyocytes, as detected by immunocytochemistry. In addition, proteomic profiling identified that combined PFASs upregulated proteins related to extracellular matrix organization, cholesterol metabolism, and antioxidant defense, and downregulated proteins related to mitochondrial function. These results underscore the importance of evaluating PFAS mixtures to better understand cardiac risks associated with environmental exposure.
Chunhui Xu 