Diverse routes to liver regeneration.
The liver's ability to regenerate is indisputable; for example, after a two-thirds partial hepatectomy in rats all residual hepatocytes can divide, questioning the need for a specific stem cell population. On the other hand, there is a potential stem cell compartment in the canals of Hering, giving rise to ductular reactions composed of hepatic progenitor cells (HPCs) when the liver's ability to regenerate is hindered by replicative senescence, but the functional relevance of this response has been questioned. Several papers have now clarified regenerative mechanisms operative in the mouse liver, suggesting that the liver is possibly unrivalled in its versatility to replace lost tissue. Under homeostatic conditions a perivenous population of clonogenic hepatocytes operates, whereas during chronic damage a minor population of periportal clonogenic hepatocytes come to the fore, while the ability of HPCs to completely replace the liver parenchyma has now been shown.
Centre for Tumour Biology, Barts and the London School of Medicine and Dentistry, London, UK.
Malcolm R
MR
Alison
Department of Gastroenterology and Hepatology, Linkou Chang Gung Memorial Hospital, Department of Medicine, Chang Gung University, Taoyuan, Taiwan.
Wey-Ran
WR
Lin
D000818:Animals; D060465:Axin Signaling Complex / Q000502:physiology; D022781:Hepatocytes / Q000502:physiology; D006801:Humans; D008115:Liver Regeneration / Q000235:genetics / Q000502:physiology*; D051379:Mice; D051736:Proto-Oncogene Proteins c-mdm2 / Q000235:genetics; D051381:Rats; D013234:Stem Cells / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
D060465:Axin Signaling Complex; D016159:Tumor Suppressor Protein p53; D051736:Proto-Oncogene Proteins c-mdm2
Axin2; Mdm2; diploid hepatocytes; hepatic progenitor cells; hybrid hepatocytes; lineage tracing; liver regeneration; p53; stem cell niche