The IGF2BP3/Notch/Jag1 pathway: A key regulator of hepatic stellate cell ferroptosis in liver fibrosis

Introduction: Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), which involves various epigenetic modifications.

Objectives: N⁶-methyladenosine (m⁶A), the most prevalent RNA modification in eukaryotic cells, influences numerous physiological and pathological processes. Nevertheless, the role of insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3), a reader gene mediating m⁶A modifications, in liver fibrosis remains unclear.

Methods and results: This study demonstrated that IGF2BP3 knockout reduces liver fibrosis by promoting HSC ferroptosis (FPT) and inactivating HSCs. Multi-omics analysis revealed that HSC-specific IGF2BP3 knockout decreased m⁶A content in Jagged1 (Jag1), a key component of the Notch signalling pathway. Furthermore, IGF2BP3 deficiency significantly reduced the expression of hairy and enhancer of split-1 (Hes1), a transcription factor in the Notch/Jag1 signalling pathway, with mRNA levels declining to 35%-62% and protein levels to 28%-35%. Additionally, it suppressed glutathione peroxidase 4 (GPX4) (decreased to approximately 31%-38%), a negative regulator of FPT, thereby facilitating HSC FPT progression and reducing profibrotic gene expression.

Conclusion: These findings uncover a novel IGF2BP3/Notch/Jag1 signalling pathway involving HSC FPT, suggesting promising targets for ameliorating liver fibrosis.

Key points/highlights: IGF2BP3 deficiency inactivates Jag1 signalling. IGF2BP3 deficiency-mediated m⁶A modifications promote HSC ferroptosis. IGF2BP3 inhibition facilitates ferroptosis in HSCs via the Hes1/GPX4 axis. IGF2BP3 deficiency inactivates Jag1/Notch1/3/Hes1 signalling pathway inactivation, leading to the decrease in GPX4, which contributes to HSC ferroptosis.