NADPH oxidase 4 (Nox4) deletion accelerates liver regeneration in mice
M. Herranz-Itúrbide,
J. López-Luque,
E. Gonzalez-Sanchez,
D. Caballero-Díaz,
E. Crosas-Molist,
B. Martín-Mur,
M. Gut,
A. Esteve-Codina,
V. Jaquet,
J.X. Jiang,
N.J. Török,
I. Fabregat
Affiliations
M. Herranz-Itúrbide
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Oncology Program, CIBEREHD, National Biomedical Research Institute on Liver and Gastrointestinal Diseases, Instituto de Salud Carlos III, Spain
J. López-Luque
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Oncology Program, CIBEREHD, National Biomedical Research Institute on Liver and Gastrointestinal Diseases, Instituto de Salud Carlos III, Spain
E. Gonzalez-Sanchez
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Oncology Program, CIBEREHD, National Biomedical Research Institute on Liver and Gastrointestinal Diseases, Instituto de Salud Carlos III, Spain; Department of Physiological Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Spain
D. Caballero-Díaz
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Oncology Program, CIBEREHD, National Biomedical Research Institute on Liver and Gastrointestinal Diseases, Instituto de Salud Carlos III, Spain
E. Crosas-Molist
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
B. Martín-Mur
CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
M. Gut
CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain
A. Esteve-Codina
CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology, Barcelona, Spain
V. Jaquet
Department of Pathology and Immunology, Medical School, University of Geneva, Geneva, Switzerland; RE.A.D.S Unit, Medical School, University of Geneva, Geneva, Switzerland
J.X. Jiang
Gastroenterology and Hepatology, UC Davis, Sacramento, CA, USA
N.J. Török
Department of Internal Medicine, Division of Gastroenterology and Hepatology, Stanford University, Stanford, CA, USA
I. Fabregat
TGF-β and Cancer Group. Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain; Oncology Program, CIBEREHD, National Biomedical Research Institute on Liver and Gastrointestinal Diseases, Instituto de Salud Carlos III, Spain; Department of Physiological Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Spain; Corresponding author. IDIBELL, Gran Vía de l'Hospitalet, 199, 08908, L'Hospitalet de Llobregat, Barcelona, Spain.
Liver is a unique organ in displaying a reparative and regenerative response after acute/chronic damage or partial hepatectomy, when all the cell types must proliferate to re-establish the liver mass. The NADPH oxidase NOX4 mediates Transforming Growth Factor-beta (TGF-β) actions, including apoptosis in hepatocytes and activation of stellate cells to myofibroblasts. Aim of this work was to analyze the impact of NOX4 in liver regeneration by using two mouse models where Nox4 was deleted: 1) general deletion of Nox4 (NOX4−/−) and 2) hepatocyte-specific deletion of Nox4 (NOX4hepKO). Liver regeneration was analyzed after 2/3 partial hepatectomy (PH). Results indicated an earlier recovery of the liver-to-body weight ratio in both NOX4−/− and NOX4hepKO mice and an increased survival, when compared to corresponding WT mice. The regenerative hepatocellular fat accumulation and the parenchyma organization recovered faster in NOX4 deleted livers. Hepatocyte proliferation, analyzed by Ki67 and phospho-Histone3 immunohistochemistry, was accelerated and increased in NOX4 deleted mice, coincident with an earlier and increased Myc expression. Primary hepatocytes isolated from NOX4 deleted mice showed higher proliferative capacity and increased expression of Myc and different cyclins in response to serum. Transcriptomic analysis through RNA-seq revealed significant changes after PH in NOX4−/− mice and support a relevant role for Myc in a node of regulation of proliferation-related genes. Interestingly, RNA-seq also revealed changes in the expression of genes related to activation of the TGF-β pathway. In fact, levels of active TGF-β1, phosphorylation of Smads and levels of its target p21 were lower at 24 h in NOX4 deleted mice. Nox4 did not appear to be essential for the termination of liver regeneration in vivo, neither for the in vitro hepatocyte response to TGF-β1 in terms of growth inhibition, which suggest its potential as therapeutic target to improve liver regeneration, without adverse effects.
