DEHP regulates ferritinophagy to promote testicular ferroptosis via suppressing SIRT1/PGC-1α pathway

To increase elasticity and flexibility, di-2-ethylhexyl phthalate (DEHP) is used in a variety of industrial products, but excessive exposure to it can pose a threat to human health. In epidemiological studies of population exposure to DEHP, attention has been paid to damage to the male reproductive system. However, the toxicological mechanism of DEHP regarding testicular injury is not well understood. We used Western blot analysis, transmission electron microscopy, fluorescence staining, transient transfection and assay kit to detect relevant indicators, and the results were as follows: After DEHP exposure, the expression levels of ACSL4, COX2, TF, FTH1, LC3, AMPK, p-AMPK, ULK1, p-ULK1, serum iron, tissue iron and MDA in the exposure group were significantly increased. The expression levels of GPX4, NCOA4, p62, SIRT1, and PGC-1α, as well as the contents of GSH and ATP, decreased. Electron microscopy showed that more autophagosomes were observed. Our findings suggest that exposure to DEHP induced ferritinophagy and ferroptosis in the testis. In vitro, the promoting effect of ferritinophagy on ferroptosis was verified by applying the autophagy inhibitor (3-MA) and si-NCOA4. Moreover, Mono-(2-ethylhexyl) phthalate (MEHP) inhibited the mitochondrial regulatory protein SIRT1/PGC-1α, leading to mitochondrial dysfunction. Changes in mitochondrial reactive oxygen species (MtROS) and energy over-activated AMPK/ULK1 autophagy pathway, and then promoted ferritinophagy, which increased the sensitivity of TM4 cells to ferroptosis. This research offers a theoretical framework for the prevention and management of DEHP-induced harm.