Dibutyl phthalate (DBP) is a widely used plasticizer that has been shown to induce germ cell apoptosis-related testicular atrophy and cause reproductive toxicity. Our previous results indicated that endoplasmic reticulum (ER) stress-activated autophagy served as a self-defense mechanism against DBP-induced germ cell apoptosis. However, the specific pathways that link ER stress and autophagy remain unclear. Here, we showed that exposure to DBP enhanced autophagic flux in mouse spermatocyte-derived GC-2 cells and that the eukaryotic translation initiation factor 2/activating transcription factor 4 pathway mediated ER stress-related autophagy independent of the mTOR and Beclin-1 pathways. Moreover, we demonstrated that DBP treatment led to the generation of reactive oxygen species (ROS) and that the inhibition of ROS by melatonin abrogated both ER stress and autophagy. The results indicated that excessive ROS production might be involved in DBP-induced ER stress and autophagy in GC-2 cells. Thus, ROS may serve as upstream mediators of ER stress and autophagy in DBP-treated GC-2 cells.
Keywords: Autophagy; dibutyl phthalate; endoplasmic reticulum stress; reactive oxygen species.