Heme oxygenase 1 alleviates nonalcoholic steatohepatitis by suppressing hepatic ferroptosis

BackgroundHeme oxygenase 1 (HO-1) has an influential but insufficiently investigated effect on ferroptosis, which is a novel form of programmed cell death and may play an effect on nonalcoholic steatohepatitis (NASH). However, the understanding of the mechanism is limited. Herein, our study aimed to explore the mechanism and role of HO-1 in NASH ferroptosis.MethodsHepatocyte conditional HO-1 knockout (HO-1(HEPKO)) C57BL/6J mice were established and fed a high-fat diet (HFD). Additionally, wild-type mice were fed either a normal diet or a HFD. Hepatic steatosis, inflammation, fibrosis, lipid peroxidation, and iron overload were assessed. AML12 and HepG2 cells were used to investigate the underlying mechanisms in vitro. Finally, liver sections from NASH patients were used to clinically validate the histopathology of ferroptosis.ResultsIn mice, HFD caused lipid accumulation, inflammation, fibrosis, and lipid peroxidation, which were aggravated by HO-1(HEPKO). In line with the in vivo results, HO-1 knockdown upregulated reactive oxygen species accumulation, lipid peroxidation, and iron overload in AML12 and HepG2 cells. Additionally, HO-1 knockdown reduced the GSH and SOD levels, which was in contrast to HO-1 overexpression in vitro. Furthermore, the present study revealed that the NF-& kappa;B signaling pathway was associated with ferroptosis in NASH models. Likewise, these findings were consistent with the liver histopathology results of NASH patients.ConclusionThe current study showed that HO-1 could alleviate NASH progression by mediating ferroptosis.

Automated summary

This study found that heme oxygenase 1 (HO-1) plays an important role in ferroptosis in nonalcoholic steatohepatitis (NASH). HO-1 deficiency exacerbates the pathological manifestations of NASH, while HO-1 overexpression alleviates NASH progression. Mechanistic studies have shown that the NF-κB signaling pathway is associated with ferroptosis in NASH.