Manuel Winkler1, Theresa Staniczek2, Sina Wietje Kürschner2, Christian David Schmid2, Hiltrud Schönhaber2, Julio Cordero3, Linda Kessler3, Arthur Mathes3, Carsten Sticht4, Michelle Neßling5, Alexey Uvarovskii6, Simon Anders6, Xue-Jun Zhang7, Guido von Figura8, Daniel Hartmann9, Carolin Mogler10, Gergana Dobreva3, Kai Schledzewski2, Cyrill Géraud11, Philipp-Sebastian Koch12, Sergij Goerdt13. 1. Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, and Center of Excellence in Dermatology, Mannheim, Germany. Electronic address: manuel.winkler@medma.uni-heidelberg.de. 2. Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, and Center of Excellence in Dermatology, Mannheim, Germany. 3. Department of Anatomy and Developmental Biology, European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. 4. Core Facility Next Generation Sequencing, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. 5. Central Unit Electron Microscopy, German Cancer Research Center (DKFZ), Heidelberg, Germany. 6. Center for Molecular Biology (ZMBH), Heidelberg University, Heidelberg, Germany. 7. Department of Surgery, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany; Department of Orthopedic Surgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China. 8. II. Medical Clinic and Policlinic, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. 9. Department of Surgery, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany. 10. Institute of Pathology, School of Medicine, Technical University of Munich, Munich, Germany. 11. Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, and Center of Excellence in Dermatology, Mannheim, Germany; Section of Clinical and Molecular Dermatology, Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany; European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. 12. Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, and Center of Excellence in Dermatology, Mannheim, Germany; European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany. Electronic address: philipp.koch@umm.de. 13. Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University, and Center of Excellence in Dermatology, Mannheim, Germany; European Center for Angioscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
Abstract
BACKGROUND & AIMS: Angiocrine signaling by liver sinusoidal endothelial cells (LSECs) regulates hepatic functions such as growth, metabolic maturation, and regeneration. Recently, we identified GATA4 as the master regulator of LSEC specification during development. Herein, we studied the role of endothelial GATA4 in the adult liver and in hepatic pathogenesis. METHODS: We generated adult Clec4g-icretg/0xGata4fl/fl (Gata4LSEC-KO) mice with LSEC-specific depletion of Gata4. Livers were analyzed by histology, electron microscopy, immunohistochemistry/immunofluorescence, in situ hybridization, and LSECs were isolated for gene expression profiling, ChIP- and ATAC-sequencing. Partial hepatectomy was performed to assess regeneration. We used choline-deficient, l-amino acid-defined (CDAA) diet and chronic carbon tetrachloride exposure to model liver fibrosis. Human single cell RNA-seq data sets were analyzed for endothelial alterations in healthy and cirrhotic livers. RESULTS: Genetic Gata4 deficiency in LSECs of adult mice caused perisinusoidal liver fibrosis, hepatopathy and impaired liver regeneration. Sinusoidal capillarization and LSEC-to-continuous endothelial transdifferentiation were accompanied by a profibrotic angiocrine switch involving de novo endothelial expression of hepatic stellate cell-activating cytokine PDGFB. Increased chromatin accessibility and amplification by activated MYC mediated angiocrine Pdgfb expression. As observed in Gata4LSEC-KO livers, CDAA diet-induced perisinusoidal liver fibrosis was associated with GATA4 repression, MYC activation and a profibrotic angiocrine switch in LSECs. Comparison of CDAA-fed Gata4LSEC-KO and control mice demonstrated that endothelial GATA4 indeed protects against dietary-induced perisinusoidal liver fibrosis. In human cirrhotic livers, GATA4-positive LSECs and endothelial GATA4 target genes were reduced, while non-LSEC endothelial cells and MYC target genes including PDGFB were enriched. CONCLUSIONS: Endothelial GATA4 protects against perisinusoidal liver fibrosis by repressing MYC activation and profibrotic angiocrine signaling at the chromatin level. Therapies targeting the GATA4/MYC/PDGFB/PDGFRβ axis offer a promising strategy for prevention and treatment of liver fibrosis. LAY SUMMARY: The liver vasculature is supposed to play a major role in the development of liver fibrosis and cirrhosis, which can lead to liver failure and liver cancer. Herein, we discovered that structural and transcriptional changes induced by genetic deletion of the transcription factor GATA4 in the hepatic endothelium were sufficient to cause liver fibrosis. Activation of the transcription factor MYC and de novo expression of the "angiocrine" growth factor PDGFB were identified as downstream drivers of fibrosis and as potential therapeutic targets for this potentially fatal disease.
BACKGROUND & AIMS: Angiocrine signaling by liver sinusoidal endothelial cells (LSECs) regulates hepatic functions such as growth, metabolic maturation, and regeneration. Recently, we identified GATA4 as the master regulator of LSEC specification during development. Herein, we studied the role of endothelial GATA4 in the adult liver and in hepatic pathogenesis. METHODS: We generated adult Clec4g-icretg/0xGata4fl/fl (Gata4LSEC-KO) mice with LSEC-specific depletion of Gata4. Livers were analyzed by histology, electron microscopy, immunohistochemistry/immunofluorescence, in situ hybridization, and LSECs were isolated for gene expression profiling, ChIP- and ATAC-sequencing. Partial hepatectomy was performed to assess regeneration. We used choline-deficient, l-amino acid-defined (CDAA) diet and chronic carbon tetrachloride exposure to model liver fibrosis. Human single cell RNA-seq data sets were analyzed for endothelial alterations in healthy and cirrhotic livers. RESULTS: Genetic Gata4 deficiency in LSECs of adult mice caused perisinusoidal liver fibrosis, hepatopathy and impaired liver regeneration. Sinusoidal capillarization and LSEC-to-continuous endothelial transdifferentiation were accompanied by a profibrotic angiocrine switch involving de novo endothelial expression of hepatic stellate cell-activating cytokine PDGFB. Increased chromatin accessibility and amplification by activated MYC mediated angiocrine Pdgfb expression. As observed in Gata4LSEC-KO livers, CDAA diet-induced perisinusoidal liver fibrosis was associated with GATA4 repression, MYC activation and a profibrotic angiocrine switch in LSECs. Comparison of CDAA-fed Gata4LSEC-KO and control mice demonstrated that endothelial GATA4 indeed protects against dietary-induced perisinusoidal liver fibrosis. In human cirrhotic livers, GATA4-positive LSECs and endothelial GATA4 target genes were reduced, while non-LSEC endothelial cells and MYC target genes including PDGFB were enriched. CONCLUSIONS: Endothelial GATA4 protects against perisinusoidal liver fibrosis by repressing MYC activation and profibrotic angiocrine signaling at the chromatin level. Therapies targeting the GATA4/MYC/PDGFB/PDGFRβ axis offer a promising strategy for prevention and treatment of liver fibrosis. LAY SUMMARY: The liver vasculature is supposed to play a major role in the development of liver fibrosis and cirrhosis, which can lead to liver failure and liver cancer. Herein, we discovered that structural and transcriptional changes induced by genetic deletion of the transcription factor GATA4 in the hepatic endothelium were sufficient to cause liver fibrosis. Activation of the transcription factor MYC and de novo expression of the "angiocrine" growth factor PDGFB were identified as downstream drivers of fibrosis and as potential therapeutic targets for this potentially fatal disease.
Authors: Kaela Drzewiecki; Jungmin Choi; Joseph Brancale; Michael A Leney-Greene; Sinan Sari; Buket Dalgiç; Aysel Ünlüsoy Aksu; Gülseren Evirgen Şahin; Ahmet Ozen; Safa Baris; Elif Karakoc-Aydiner; Dhanpat Jain; David Kleiner; Michael Schmalz; Kadakkal Radhakrishnan; Junhui Zhang; Kasper Hoebe; Helen C Su; João P Pereira; Michael J Lenardo; Richard P Lifton; Sílvia Vilarinho Journal: J Exp Med Date: 2021-05-06 Impact factor: 14.307
Authors: Nicolò Manicardi; Anabel Fernández-Iglesias; Laia Abad-Jordà; Felix Royo; Mikel Azkargorta; Martí Ortega-Ribera; David Sanfeliu-Redondo; Ana Martínez-Alcocer; Felix Elortza; Amelia J Hessheimer; Constantino Fondevila; Juan José Lozano; Juan Carlos García-Pagán; Jaime Bosch; Francisco Javier Cubero; Agustín Albillos; Javier Vaquero; Juan M Falcón-Pérez; Jordi Gracia-Sancho Journal: Cancers (Basel) Date: 2021-05-29 Impact factor: 6.639