Cell-matrix interactions control biliary organoid polarity, architecture, and differentiation

Area of Science:

• Hepatology and Gastroenterology
• Stem Cell Biology
• Organoid Technology

Background:

• Cholangiopathies (bile duct diseases) cause significant illness but lack effective human disease models.
• Current 3D biliary organoids have limited applications due to inaccessible apical poles and extracellular matrix (ECM) interference.
• Investigating ECM signals is crucial for developing novel organotypic culture systems for cholangiopathies.

Purpose of the Study:

• To develop a novel organotypic culture system for studying cholangiopathies.
• To overcome limitations of existing 3D biliary organoids by manipulating ECM interactions.
• To generate a more accessible and functionally relevant human biliary organoid model.

Main Methods:

• Generated 3D biliary organoids from human livers embedded in ECM.
• Developed an 'apical-out' organoid (AOO) model by removing organoids from ECM, exposing the apical membrane.
• Utilized functional assays, microscopy (immunohistochemistry, TEM), and transcriptomics (bulk and single-cell).

Main Results:

• AOOs exhibited reduced heterogeneity, enhanced biliary differentiation, and decreased stem cell markers compared to embedded organoids.
• AOOs demonstrated functional bile acid transport and competent tight junctions.
• Coculture with Enterococcus spp. induced chemokine secretion in AOOs, and beta-1-integrin signaling was identified as key to polarity regulation.

Conclusions:

• The novel AOO model provides a platform for studying bile transport, pathobiont interactions, and epithelial permeability.
• This model facilitates research into cholangiopathies, liver diseases, and the impact of ECM on biliary epithelium.
• AOOs offer key insights into the pathobiology of cholangiopathies and related liver conditions.