Liver polyploidisation, characterised by accumulation of tetraploid and octaploid cells, is found with increasing age and after administration of various drugs. The significance and mechanisms controlling polyploidisation are not understood but p53 is a candidate gene to be involved. We have investigated the effect of p53 on sodium phenobarbitone (PB)-induced liver proliferation and polyploidisation. Using p53 wild type (+/+), heterozygous (+/-) and homozygous (-/-) C57BL/6J mice, we measured ploidy and proliferation (BrdU incorporation) after 21 days oral administration of PB. Administration of PB caused a striking ploidy change compared with untreated controls, with an increase in 8n cells, and no difference noted comparing the p53 genotypes. BrdU positivity also increased significantly compared with controls, with the increase in BrdU positivity occurring in 8n cells. Our results confirm that PB is a hepatic mitogen that causes liver polyploidisation with a striking increase in 8n cells within the liver. p53 status does not appear to have any effect on this PB-induced ploidy change.
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http://dx.doi.org/10.1016/s0378-4274(00)00299-x | DOI Listing |
J Hepatol
August 2024
Helmholtz Pioneer Campus (HPC), Helmholtz Munich, Neuherberg, Germany; TUM School of Medicine, Technical University of Munich, Munich, Germany; Institute of Biotechnology and Biomedicine (BIOTECMED), Department of Biochemistry and Molecular Biology, University of Valencia, Burjassot, Spain. Electronic address:
Background & Aims: Polyploidy in hepatocytes has been proposed as a genetic mechanism to buffer against transcriptional dysregulation. Here, we aim to demonstrate the role of polyploidy in modulating gene regulatory networks in hepatocytes during ageing.
Methods: We performed single-nucleus RNA sequencing in hepatocyte nuclei of different ploidy levels isolated from young and old wild-type mice.
Nat Commun
March 2024
MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, UK.
DNA repair deficiency can lead to segmental phenotypes in humans and mice, in which certain tissues lose homeostasis while others remain seemingly unaffected. This may be due to different tissues facing varying levels of damage or having different reliance on specific DNA repair pathways. However, we find that the cellular response to DNA damage determines different tissue-specific outcomes.
View Article and Find Full Text PDFJHEP Rep
October 2023
Department of Pathology and Molecular Pathology, University Hospital Zürich (USZ), Zurich, Switzerland.
Background & Aims: Mcl-1, an antiapoptotic protein overexpressed in many tumours, including hepatocellular carcinoma (HCC), represents a promising target for cancer treatment. Although Mcl-1 non-apoptotic roles might critically influence the therapeutic potential of Mcl-1 inhibitors, these functions remain poorly understood. We aimed to investigate the effects of hepatic Mcl-1 deficiency (Mcl-1) on hepatocyte ploidy and cell cycle in murine liver and the possible implications on HCC.
View Article and Find Full Text PDFJ Hepatol
November 2021
Institute for Developmental Immunology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria; Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases (LBI-RUD), 1090 Vienna, Austria; CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria. Electronic address:
A balanced increase in DNA content (ploidy) is observed in some human cell types, including bone-resorbing osteoclasts, platelet-producing megakaryocytes, cardiomyocytes or hepatocytes. The impact of increased hepatocyte ploidy on normal physiology and diverse liver pathologies is still poorly understood. Recent findings suggest swift genetic adaptation to hepatotoxic stress and the protection from malignant transformation as beneficial effects.
View Article and Find Full Text PDFCell Tissue Res
December 2016
Department of Cytobiology and Cytopathobiology, Philipps University, 35033, Marburg, Germany.
Autophagy is a lysosomal degradation process involved in the turnover of organelles or other cell constituents, in providing sources for energy production under starving conditions and in cell metabolism. A key protein in the macroautophagic machinery is the autophagy-related protein (Atg) 7. Constitutive deletion of Atg7 is lethal at birth.
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