Modeling Disease-Relevant Bile Duct Morphogenesis Defects in a Tunable In Vitro System

Area of Science:

• Developmental Biology
• Cell Biology
• Regenerative Medicine

Background:

• Biliary tubulogenesis is crucial for liver function but challenging to study in vivo.
• Existing 3D models lack control over duct development, hindering mechanistic insights.
• Alagille syndrome involves defects in bile duct formation, necessitating better research models.

Purpose of the Study:

• To develop a novel micropattern-based in vitro platform for studying biliary tubulogenesis.
• To investigate the role of Notch signaling and epidermal growth factor (EGF) in bile duct morphogenesis.
• To model key features of Alagille syndrome using this platform.

Main Methods:

• Utilized a micropattern-based platform to constrain cholangiocyte growth in defined geometries.
• Introduced Jag1 mutations or Notch inhibition (CB-103) to mimic Alagille syndrome.
• Performed quantitative morphometric analysis, time-lapse imaging, and coculture with HUVECs.

Main Results:

• The platform enabled reproducible tubular structure formation with controlled folding, lumenization, and branching.
• Notch inhibition recapitulated Alagille syndrome features: reduced tube width, impaired folding, and defective branching.
• EGF promoted folding and proliferation but did not rescue branching defects; Notch activity is essential for tube expansion.

Conclusions:

• The micropattern platform provides a powerful tool for quantitative analysis of bile duct development.
• Notch signaling is critical for the sequential folding-expansion cycle in tube formation.
• This system facilitates the study of developmental defects and exploration of regenerative strategies for biliary disorders.