Activation of Nrf2 signaling protects hypoxia-induced HTR-8/SVneo cells against ferroptosis.

Abstract

This article aims to investigate the possible mechanism by which nuclear factor erythroid 2-related factor 2 (Nrf2) signaling exerts protective effects on the progression of preeclampsia (PE). HTR-8/SVneo cells were cultured under hypoxic conditions to establish PE cell model. Cell viability and invasion were respectively examined by CCK-8 assay and transwell assay. The detection of oxidative stress and Fe2+ content was carried out by corresponding commercial kits, and the expression of corresponding proteins and genes was detected by western blot and qPCR. After Nrf2 was overexpressed in HTR-8/SVneo cells, the above assays were conducted to confirm the exact effects of Nrf2 activation on ferroptosis. Hypoxia reduced the invasion of HTR-8/SVneo cells, induced oxidative stress (upregulated levels of glutathione [GSH], malondialdehyde [MDA], and reactive oxygen species [ROS]), and induced ferroptosis which exhibited by upregulated Fe2+ and downregulated expression of solute carrier family 7 member 11/System xCT (SCL7A11), glutathione peroxidase 4 (GPX4), and ferroportin1 (FPN1). Meanwhile, hypoxia promoted the translocation of Nrf2 to the nucleus, leading to Nrf2/HO-1 signaling activation. These changes upon hypoxia induction were strengthened by ferric ammonium citrate (FAC) but were abolished by deferoxamine (DFO). Moreover, Nrf2 overexpression in hypoxia-induced HTR-8/SVneo cells exerted inhibitory effects on levels of GSH, MDA, ROS, and Fe2+ , and promotive effects on Nrf2/HO-1 signaling activation and expression of SCL7A11, GPX4, and FPN1, indicating that Nrf2 overexpression decreased oxidative stress and ferroptosis in hypoxia-induced HTR-8/SVneo cells. Collectively, activation of Nrf2 signaling alleviated hypoxia-induced invasion lacking, oxidative stress, and ferroptosis in hypoxia-induced HTR-8/SVneo cells, suggesting that Nrf2 signaling activation play a protective role in PE, which can provide instructions for the targeted treatment of PE.