ACSL4 contributes to sevoflurane-induced ferroptotic neuronal death in SH-SY5Y cells via the 5' AMP-activated protein kinase/mammalian target of rapamycin pathway

BACKGROUND: Acyl-CoA synthetase long chain family member 4 (ACSL4) has been reported to serve as a major player in the progress of ferroptosis in various diseases. Nevertheless, the functional role and mechanism of ACSL4 in sevoflurane (sev)-induced neuronal death has never been elucidated. METHODS: Cell viability was assessed using Cell Counting Kit-8 (CCK-8). Iron levels, reactive oxygen species (ROS) production, and malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and glutathione (GSH) content were determined to assess ferroptosis level. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot were undertaken for the measurement of gene expression. RESULTS: Sev hindered the viability of SH-SY5Y cells and suppression of ferroptosis by ferrostatin-1 (Fer-1) mitigated sev-induced inhibition of SH-SY5Y cell viability. Sev treatment increases the Fe(2+) level and decreases the mRNA levels of SLC7A11 and GPX4 in SH-SY5Y cells. Sev increased the expression of ACSL4. Moreover, silencing of ACSL4 could abrogate sev-induced cell damage, as evidenced by increases in cell viability, GPX4 protein levels, and decreases in iron levels, ROS production, and MDA and 4-HNE content. Remarkably, sev hindered the activation of the 5' AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling, which was diminished by knockdown of ACSL4. Moreover, inhibition of the AMPK/mTOR signaling by compound C could mitigate the protective effect of ACSL4 silencing against sev-induced ferroptotic cell death. CONCLUSIONS: Downregulation of ACSL4 restrained sev-induced ferroptotic cell death via AMPK/mTOR signaling, providing the basis for an approach to alleviate sev-induced postoperative cognitive dysfunction (POCD).