Autoimmune Hepatic Failure Following Acute Hepatitis A is Accompanied by Inflammatory Conversion of Regulatory T Cells

Sulforaphane, an NRF2 agonist, alleviates ferroptosis in acute liver failure by regulating HDAC6 activity

OBJECTIVE

Acute liver failure (ALF) is characterized by severe liver dysfunction, rapid progression and high mortality and is difficult to treat. Studies have found that sulforaphane (SFN), a nuclear factor E2-related factor 2 (NRF2) agonist, has anti-inflammatory, antioxidant and anticancer effects, and has certain protective effects on neurodegenerative diseases, cancer and liver fibrosis. This paper aimed to explore the protective effect of SFN in ALF and it possible mechanisms of action.

METHODS

Lipopolysaccharide and D-galactosamine were used to induce liver injury in vitro and in vivo. NRF2 agonist SFN and histone deacetylase 6 (HDAC6) inhibitor ACY1215 were used to observe the protective effect and possible mechanisms of SFN in ALF, respectively. Cell viability, lactate dehydrogenase (LDH), Fe2+, glutathione (GSH) and malondialdehyde (MDA) were detected. The expression of HDAC6, NRF2, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and solute carrier family 7 member 11 (SLC7A11) were detected by Western blotting and immunofluorescence.

RESULTS

Our results show that NRF2 was activated by SFN. LDH, Fe2+, MDA and ACSL4 were downregulated, while GSH, GPX4 and SLC7A11 were upregulated by SFN in vitro and in vivo, indicating the inhibitory effect of SFN on ferroptosis. Additionally, HDAC6 expression was decreased in the SFN group, indicating that SFN could downregulate the expression of HDAC6 in ALF. After using the HDAC6 inhibitor, ACY1215, SFN further reduced HDAC6 expression and inhibited ferroptosis, indicating that SFN may inhibit ferroptosis by regulating HDAC6 activity.

CONCLUSION

SFN has a protective effect on ALF, and the mechanism may include reduction of ferroptosis through the regulation of HDAC6. Please cite this article as: Zhang YQ, Shi CX, Zhang DM, Zhang LY, Wang LW, Gong ZJ. Sulforaphane, an NRF2 agonist, alleviates ferroptosis in acute liver failure by regulating HDAC6 activity. J Integr Med. 2023; 21(5): 464-473.

Approach to the patient with acute severe autoimmune hepatitis

Autoimmune hepatitis is associated with varied clinical presentations and natural history, as well as somewhat unpredictable treatment responses. Understanding how to stratify patients who require further escalation of therapy will help clinicians manage these patients. The presentation of acute severe autoimmune hepatitis (AS-AIH) is relatively uncommon, although its prevalence is potentially greater than currently perceived. Previous studies consist of small retrospective single-centre series and are not directly comparable due to the diversity of presentations, disease definitions and non-standardised treatment regimens. We define AS-AIH as those who present acutely with AIH and are icteric with an international normalised ratio ≥1.5 and no evidence of hepatic encephalopathy. Those with hepatic encephalopathy should be defined as having AS-AIH with acute liver failure. In this review, we provide a structured practical approach for diagnosing and managing this unique group of patients.