Back to Search
Start Over
Regenerative failure of intrahepatic biliary cells in Alagille syndrome rescued by elevated Jagged/Notch/Sox9 signaling.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2022 Dec 13; Vol. 119 (50), pp. e2201097119. Date of Electronic Publication: 2022 Dec 05. - Publication Year :
- 2022
-
Abstract
- Despite the robust healing capacity of the liver, regenerative failure underlies numerous hepatic diseases, including the JAG1 haploinsufficient disorder, Alagille syndrome (ALGS). Cholestasis due to intrahepatic duct (IHD) paucity resolves in certain ALGS cases but fails in most with no clear mechanisms or therapeutic interventions. We find that modulating jag1b and jag2b allele dosage is sufficient to stratify these distinct outcomes, which can be either exacerbated or rescued with genetic manipulation of Notch signaling, demonstrating that perturbations of Jag/Notch signaling may be causal for the spectrum of ALGS liver severities. Although regenerating IHD cells proliferate, they remain clustered in mutants that fail to recover due to a blunted elevation of Notch signaling in the distal-most IHD cells. Increased Notch signaling is required for regenerating IHD cells to branch and segregate into the peripheral region of the growing liver, where biliary paucity is commonly observed in ALGS. Mosaic loss- and-gain-of-function analysis reveals Sox9b to be a key Notch transcriptional effector required cell autonomously to regulate these cellular dynamics during IHD regeneration. Treatment with a small-molecule putative Notch agonist stimulates Sox9 expression in ALGS patient fibroblasts and enhances hepatic sox9b expression, rescues IHD paucity and cholestasis, and increases survival in zebrafish mutants, thereby providing a proof-of-concept therapeutic avenue for this disorder.
- Subjects :
- Animals
Humans
Jagged-1 Protein genetics
Jagged-1 Protein metabolism
Mosaicism
SOX9 Transcription Factor genetics
SOX9 Transcription Factor metabolism
Zebrafish genetics
Zebrafish metabolism
Receptors, Notch genetics
Receptors, Notch metabolism
Regeneration
Fibroblasts
Alagille Syndrome genetics
Alagille Syndrome metabolism
Signal Transduction
Bile Ducts, Intrahepatic cytology
Bile Ducts, Intrahepatic pathology
Subjects
Details
- Language :
- English
- ISSN :
- 1091-6490
- Volume :
- 119
- Issue :
- 50
- Database :
- MEDLINE
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 36469766
- Full Text :
- https://doi.org/10.1073/pnas.2201097119