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

ABSTRACT Introduction Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), which involves various epigenetic modifications. Objectives N 6 ‐methyladenosine (m 6 A), 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 m 6 A 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 m 6 A 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 m 6 A 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.