Department of Occupational and Environmental Health, Dalian Medical University, 9 Lvshun South Road, Dalian, 116044, PR China.
Department of Nutrition and Food Hygiene, Dalian Medical University, 9 Lvshun South Road, Dalian, 116044, PR China.
Environ Res. 2020 Sep;188:109824. doi: 10.1016/j.envres.2020.109824. Epub 2020 Jun 23.
Exposure to arsenic is a risk factor for nonalcoholic steatohepatitis (NASH). Ferroptosis is a form of regulated cell death defined by the accumulation of lipid peroxidation. In the current study, we observed the occurrence of ferroptosis in arsenic-induced NASH by assessing ferroptosis related hallmarks. In vitro, we found that ferrostatin-1 effectively attenuated the executing of ferroptosis and NASH. Simultaneously, the expression of ACSL4 (acyl-CoA synthetase long-chain family member 4) was upregulated in rat's liver and L-02 cells exposed to arsenic. While, suppression of ACSL4 with rosiglitazone or ACSL4 siRNA remarkably alleviated arsenic-induced NASH and ferroptosis through diminishing 5-hydroxyeicosatetraenoic acid (5-HETE) content. Additionally, Mitofusin 2 (Mfn2), a physical tether between endoplasmic reticulum and mitochondria, has rarely been explored in the ferroptosis. Using Mfn2 siRNA or inositol-requiring enzyme 1 alpha (IRE1α) inhibitor, we found NASH and ferroptosis were obviously mitigated through reducing 5-HETE content. Importantly, Co-IP assay indicated that Mfn2 could interact with IRE1α and promoted the production of 5-HETE, ultimately led to ferroptosis and NASH. Collectively, our data showed that ferroptosis is involved in arsenic-induced NASH. These data provide insightful viewpoints into the mechanism of arsenic-induced NASH.
砷暴露是导致非酒精性脂肪性肝炎(NASH)的一个风险因素。铁死亡是一种受调控的细胞死亡形式,其特征是脂质过氧化的积累。在本研究中,我们通过评估铁死亡相关标志物观察到了砷诱导的 NASH 中铁死亡的发生。在体外,我们发现铁死亡抑制剂 ferrostatin-1 可有效减轻铁死亡和 NASH 的发生。同时,我们发现暴露于砷的大鼠肝脏和 L-02 细胞中酰基辅酶 A 合成酶长链家族成员 4(ACSL4)的表达上调。然而,用罗格列酮或 ACSL4 siRNA 抑制 ACSL4 通过减少 5-羟二十碳四烯酸(5-HETE)含量,可显著减轻砷诱导的 NASH 和铁死亡。此外,线粒体和内质网之间的物理连接蛋白 Mitofusin 2(Mfn2)在铁死亡中很少被探索。使用 Mfn2 siRNA 或肌醇需求酶 1α(IRE1α)抑制剂,我们发现通过降低 5-HETE 含量,NASH 和铁死亡明显减轻。重要的是,Co-IP 实验表明 Mfn2 可以与 IRE1α 相互作用并促进 5-HETE 的产生,最终导致铁死亡和 NASH。总之,我们的数据表明铁死亡参与了砷诱导的 NASH。这些数据为砷诱导 NASH 的机制提供了有见地的观点。