Z Gastroenterol 2019; 57(01): e14
DOI: 10.1055/s-0038-1677076
1. Basic Hepatology (Fibrogenesis, NPC, Transport)
Georg Thieme Verlag KG Stuttgart · New York

Cellular and nuclear hepatocyte ploidy represent a repository in regenerating livers

S Hammad
1   Molecular Hepatology Section, Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany, Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt.
,
U Dahmen
2   Department of General, Visceral and Vascular Surgery, Jena University Hospital, Drackendorfer Str. 1, 07747, Jena, Germany
,
A Othman
3   Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 44139, Dortmund, Germany.
,
I von Recklinghausen
4   Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 44139, Dortmund, Germany.
,
JG Hengstler
5   Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund (IfADo), 44139, Dortmund, Germany.
,
U Klingmüller
6   Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), INF 280, 69120 Heidelberg, Germany.
,
S Dooley
7   Molecular Hepatology Section, Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, 68167, Mannheim, Germany
› Author Affiliations
Further Information

Publication History

Publication Date:
04 January 2019 (online)

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The adult liver consists of various ploidy classes of hepatocytes, including mononuclear and binuclear cells. Nuclear division without subsequent cytokinesis is generating the different ploidy classes of hepatocytes postnatally. The exact fraction of each hepatocyte class in livers that undergo resection is still not exactly described. We developed 3D analysis protocols based on vibratome liver slices (100 µm thick) for such detailed examination. Here, liver slices are co-stained with different antibodies to visualize bile canalicular and sinusoidal networks, pericentral hepatocytes and cell nuclei1. TiQuant2 software was used to analyze and quantify nuclearity and ploidy classes in mouse livers after 2/3 partial hepatectomy (PHx) as compared to sham-operated controls in a time-resolved experiment at 1 d, 2 d, 3 d, 4 d and 7days after surgery. The results were compared with in vitro data from isolated and cultured mouse hepatocytes, as well as with such from conventional 2D analyses. We found that in adult healthy mouse liver more than 75% are binucleated hepatocytes. More than 85% of the hepatocytes are polyploid in healthy livers. Approximately 50% of binuclear hepatocytes are lost 1 d after 2/3 PHx. In regenerating livers, the number of nuclei per cell decreases, however, the DNA content is increased, indicating less binuclear and more cells. Quantification of hepatocytes in S-phase indicates no preferential DNA synthesis between mono- and binuclear cells, as revealed by BrdU incorporation. Similarly, Ki-67 immunostaining revealed no differences between mono- and binucleated hepatocytes. Time-lapse microscopy of cultured HGF stimulated mouse hepatocytes revealed that more than 95% of the binucleated hepatocytes preferentially divide into two mononuclear cells after DNA synthesis. Furthermore, the number of hepatocytes with nuclear polyploidy is increased in regenerating livers, independent of cell nuclearity. In conclusion, binuclear hepatocytes and ploidy variations represent a repository for an immediate regeneration response after liver resection.

1Hammad S, Hoehme S, et al. Protocols for staining of bile canalicular and sinusoidal networks of human, mouse and pig livers, three-dimensional reconstruction and quantification of tissue microarchitecture by image processing and analysis. Arch Toxicol. 2014 May;88(5):1161 – 83.

2Friebel A, Neitsch J, et al. TiQuant: software for tissue analysis, quantification and surface reconstruction. Bioinformatics. 2015 Oct 1;31(19):3234 – 6.