title: Massive rearrangements of cellular MicroRNA signatures are key drivers of hepatocyte dedifferentiation.
abstract: Hepatocytes are dynamic cells that, upon injury, can alternate between nondividing differentiated and dedifferentiated proliferating states in vivo. However, in two-dimensional cultures, primary human hepatocytes (PHHs) rapidly dedifferentiate, resulting in loss of hepatic functions that significantly limits their usefulness as an in vitro model of liver biology, liver diseases, as well as drug metabolism and toxicity. Thus, understanding the underlying mechanisms and stalling of the dedifferentiation process would be highly beneficial to establish more-accurate and relevant long-term in vitro hepatocyte models. Here, we present comprehensive analyses of whole proteome and transcriptome dynamics during the initiation of dedifferentiation during the first 24 hours of culture. We report that early major rearrangements of the noncoding transcriptome, hallmarked by increased expression of small nucleolar RNAs, long noncoding RNAs, microRNAs (miRNAs), and ribosomal genes, precede most changes in coding genes during dedifferentiation of PHHs, and we speculated that these modulations could drive the hepatic dedifferentiation process. To functionally test this hypothesis, we globally inhibited the miRNA machinery using two established chemically distinct compounds, acriflavine and poly-l-lysine. These inhibition experiments resulted in a significantly impaired miRNA response and, most important, in a pronounced reduction in the down-regulation of hepatic genes with importance for liver function. Thus, we provide strong evidence for the importance of noncoding RNAs, in particular, miRNAs, in hepatic dedifferentiation, which can aid the development of more-efficient differentiation protocols for stem-cell-derived hepatocytes and broaden our understanding of the dynamic properties of hepatocytes with respect to liver regeneration.
  
  
  
  miRNAs are important drivers of hepatic dedifferentiation, and our results provide valuable information regarding the mechanisms behind liver regeneration and possibilities to inhibit dedifferentiation in vitro. (Hepatology 2016;64:1743-1756).
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. volker.lauschke@ki.se.
authors.forename: Volker M
authors.identifier: 0000-0002-1140-6204
authors.initials: VM
authors.lastname: Lauschke
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sabine U
authors.initials: SU
authors.lastname: Vorrink
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sabrina M L
authors.initials: SM
authors.lastname: Moro
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Fatemah
authors.initials: F
authors.lastname: Rezayee
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Nordling
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Delilah F G
authors.initials: DF
authors.lastname: Hendriks
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Bell
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.
authors.forename: Rowena
authors.initials: R
authors.lastname: Sison-Young
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.
authors.forename: B Kevin
authors.initials: BK
authors.lastname: Park
authors.affiliation: MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Goldring
authors.affiliation: Department of Clinical Science, Intervention and Technology, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ewa
authors.identifier: 0000-0002-3057-5337
authors.initials: E
authors.lastname: Ellis
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Inger
authors.initials: I
authors.lastname: Johansson
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Souren
authors.initials: S
authors.lastname: Mkrtchian
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.|Cardiovascular and Metabolic Diseases Innovative Medicines, DMPK, AstraZeneca R&D, Mölndal, Sweden.
authors.forename: Tommy B
authors.initials: TB
authors.lastname: Andersson
authors.affiliation: Section of Pharmacogenetics, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Ingelman-Sundberg
mesh_terms: D000328:Adult; D000368:Aged; D054337:Cell Dedifferentiation / Q000235:genetics*; D002478:Cells, Cultured; D005260:Female; D022781:Hepatocytes / Q000502:physiology*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000502:physiology*; D008875:Middle Aged; D059467:Transcriptome
chemical_list: D035683:MicroRNAs