Perfluorohexanoic Acid-Induced Inhibition of Human Palate Cell Proliferation Through Upregulation of miR-374a-5p

Per- and poly fluoroalkyl substances (PFAS) pose serious health concerns worldwide. Although the use of classical PFAS, such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), is regulated, the toxicological effects of alternative PFASs remain unknown. Cleft palate is a birth defect that is associated with environmental and genetic factors. Although an association between PFOS-induced and cleft palate has been reported, whether alternative PFASs affect cleft palate remains to be fully elucidated. The aim of this study was to clarify the involvement of classical and alternative PFAS (PFHxA and PFHxS) in the proliferation of human embryonic palatal mesenchymal cells (HEPM). Cell viability, apoptosis, and cell cycle-related markers were evaluated after PFASs treatment. In addition, miRNA levels and their downstream genes were measured, and a rescue experiment was performed using the miR-374a-5p inhibitor. Among the four PFASs, PFHxS decreased the number of cells with cyclin- and cyclin-dependent kinase reduction. In addition, PFHxS treatment upregulated miR-374a-5p and its downstream genes. Furthermore, miR-374a-5p inhibitor alleviated the PFHxS-induced inhibition of cell proliferation. These results suggest that PFHxS-induced cleft palate associated with miR-374a-5p and alternative PFAS may have a highly toxic effect on HEPM cells.