Perfluorohexanesulfonic acid-induced inhibition of human palate cell proliferation through upregulation of miR-374a-5p.

Per- and poly fluoroalkyl substances (PFAS) pose significant global health risks. 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 congenital condition influenced by both environmental and genetic factors. Although PFOS has been linked to cleft palate, the effects of other PFAS compounds remain unexplored. The aim of this study was to clarify the involvement of classical and alternative PFAS (PFHxA and PFHxS) in human embryonic palatal mesenchymal cell (HEPM) proliferation. Following PFAS treatment for 48 h, cell viability, apoptosis, and expression of cell cycle-related proteins were tested. In addition, miRNA levels and predicted target genes were measured, and a rescue experiment against PFHxS was conducted using an miR-374a-5p inhibitor. Among the four PFASs, PFHxS decreased the number of cells showing cyclin- and cyclin-dependent kinase reduction. In addition, PFHxS treatment upregulated miR-374a-5p and downregulated its downstream genes. Furthermore, miR- 374a-5p inhibitor alleviated the PFHxS-induced reduction in cell proliferation. These findings therefore indicate that miR-374a-5p plays a key role in the development of PFHxS-induced cleft palate and that alternative PFAS may have a highly toxic effect on HEPM cells.