Hepatocyte Notch activation induces liver fibrosis in nonalcoholic steatohepatitis.

Abstract

Fibrosis is the major determinant of morbidity and mortality in patients with nonalcoholic steatohepatitis (NASH) but has no approved pharmacotherapy in part because of incomplete understanding of its pathogenic mechanisms. Here, we report that hepatocyte Notch activity tracks with disease severity and treatment response in patients with NASH and is similarly increased in a mouse model of diet-induced NASH and liver fibrosis. Hepatocyte-specific Notch loss-of-function mouse models showed attenuated NASH-associated liver fibrosis, demonstrating causality to obesity-induced liver pathology. Conversely, forced activation of hepatocyte Notch induced fibrosis in both chow- and NASH diet-fed mice by increasing Sox9-dependent Osteopontin (Opn) expression and secretion from hepatocytes, which activate resident hepatic stellate cells. In a cross-sectional study, we found that OPN explains the positive correlation between liver Notch activity and fibrosis stage in patients. Further, we developed a Notch inhibitor [Nicastrin antisense oligonucleotide (Ncst ASO)] that reduced fibrosis in NASH diet-fed mice. In summary, these studies demonstrate the pathological role and therapeutic accessibility of the maladaptive hepatocyte Notch response in NASH-associated liver fibrosis.

• Authors: Changyu Zhu, KyeongJin Kim, Xiaobo Wang, Alberto Bartolome, Marcela Salomao, Paola Dongiovanni, Marica Meroni, Mark J Graham, Katherine P Yates, Anna Mae Diehl, Robert F Schwabe, Ira Tabas, Luca Valenti, Joel E Lavine, Utpal B Pajvani
• Journal: Science translational medicine (Sci Transl Med) Vol. 10 Issue 468 (11 21 2018) ISSN: 1946-6242 [Electronic] United States
• PMID: 30463916 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Chemical References

• Receptors, Notch
• SOX9 Transcription Factor
• Spp1 protein, mouse
• Osteopontin
• Methionine
• Choline

Topics

• Animals
• Choline (metabolism)
• Diet
• Female
• Hepatic Stellate Cells (metabolism)
• Hepatocytes (metabolism)
• Humans
• Liver Cirrhosis (complications, pathology)
• Male
• Methionine (deficiency)
• Mice, Inbred C57BL
• Non-alcoholic Fatty Liver Disease (complications, pathology)
• Osteopontin (metabolism)
• Receptors, Notch (metabolism)
• SOX9 Transcription Factor (metabolism)