HFPO-TA inhibits testosterone synthesis by triggering FTO-mediated m6A modification to drive NCOA4-associated ferroptosis.

Hexafluoropropylene oxide trimer acid (HFPO-TA), a widely used replacement for perfluorooctanoic acid (PFOA), has recently been detected in various environmental media and human biological samples. Its high environmental persistence and potential for bioaccumulation have raised growing concerns about its health risks. However, the molecular mechanisms underlying its male reproductive toxicity remain poorly understood. This study systematically evaluated the effects of HFPO-TA on testosterone synthesis using in vivo mouse exposure models and in vitro Leydig cell models. HFPO-TA exposure caused significant testicular damage and reduced sperm quality in mice. Additional studies revealed that HFPO-TA notably inhibited testosterone biosynthesis, both in vivo and in vitro. Mechanistic studies identified ferroptosis as the key mechanism mediating HFPO-TA-induced testosterone synthesis impairment. Furthermore, HFPO-TA exposure downregulated the expression of the demethylase FTO, leading to an abnormal elevation of m6A modification levels. During this process, the m6A reader protein IGF2BP2 enhanced its binding to Ncoa4 mRNA, thereby promoting its stability and driving ferroptosis. Additional validation in immortalized human Leydig cells and in vivo pharmacological intervention experiments provided further support for these findings. Overall, this study identifies the FTO-m6A-IGF2BP2-NCOA4 axis as a key epitranscriptomic pathway involved in HFPO-TA-induced Leydig cell dysfunction. These findings provide crucial scientific evidence for the risk assessment of emerging per- and polyfluoroalkyl substances and identify potential molecular targets for intervention against pollutant-induced male reproductive impairment.