Related Experiment Video
Updated: Aug 21, 2026

Hepatocyte-specific Ablation in Zebrafish to Study Biliary-driven Liver Regeneration
Published on: May 20, 2015
Topoisomerase 1 initiates biliary-derived liver regeneration through the Dnmt1-p53 axis
Chuanfang Qian1, Zhuolin Yang1, Xuemeng Xu1
1Institute of Developmental Biology and Regenerative Medicine, Southwest University, Chongqing 400715, China.
Abstract:
In end-stage liver disease, impaired hepatocyte proliferation prevents regeneration. Biliary epithelial cell transdifferentiation thus becomes a critical alternative for liver repair, yet its efficiency remains low in mammals. Elucidating the initiation mechanisms of this process may unlock novel therapeutic targets for end-stage liver disease treatment. By leveraging the zebrafish severe liver injury model and its transparency, as well as the availability of small-molecule research, we identified that topoisomerase 1 (Top1) is essential for the initiation of biliary-derived liver regeneration. Top1 upregulation occurred early after liver injury. Moreover, genetic knockout (top1 mutants) or pharmacological inhibition (topotecan) impeded liver regeneration by suppressing cholangiocyte dedifferentiation, promoting cell apoptosis, and blocking the redifferentiation of bipotential progenitor cells into hepatocytes and cholangiocytes. Mechanistically, Top1 activates DNA methyltransferase 1 (Dnmt1) in cholangiocytes, thereby depressing p53 during dedifferentiation, which subsequently maintains the activity of mTOR signalling in cholangiocytes to trigger regeneration initiation. These findings suggest that the Top1-Dnmt1-p53 axis orchestrates the initiation of biliary-driven liver regeneration.
Related Concept Videos
Liver Regeneration
Cells of Liver
The liver comprises four major types of cells— hepatocytes, stellate, Kupffer, and sinusoidal endothelial cells. The hepatocytes are large...
Abnormal Proliferation
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle
Cirrhosis II: Pathophysiology
Negative Regulator Molecules

