Toosendanin induced hepatotoxicity via triggering PERK-eIF2α-ATF4 mediated ferroptosis

Abstract

Toosendanin (TSN) is the main active compound of Melia toosendan Sieb et Zucc with various bioactivities. In this study, we investigated the role of ferroptosis in TSN-induced hepatotoxicity. The characteristic indicators of ferroptosis were detected including reactive oxygen species (ROS), lipid-ROS, glutathione (GSH), ferrous ion and the expression of glutathione peroxidase 4 (GPX4), which showed that TSN caused ferroptosis in hepatocytes. The results of qPCR analysis and western blotting assay showed that TSN-induced activation of protein kinase R-like endoplasmic reticulum kinase (PERK)- eukaryotic initiation factor 2 α subunit (eIF2α)- activation transcription factor 4 (ATF4) signaling pathway resulted in increasing activation transcription factor 3 (ATF3) expression, which upregulated the expression of transferrin receptor 1 (TFRC). Furthermore, TFRC mediated iron accumulation leading to ferroptosis in hepatocytes. To clarify whether TSN triggered ferroptosis in vivo, male Balb/c mice were treated with the different doses of TSN. The results of hematoxylin-eosin (H&E) staining, 4-hydroxynonenal (4-HNE) staining, malondialdehyde (MDA) content and the protein expression of GPX4 showed that ferroptosis contributed to TSN-induced hepatotoxicity. Iron homeostasis relative protein and PERK- eIF2α- ATF4 signaling pathway also involved in hepatotoxicity of TSN in vivo.