Different Biomechanical Cell Behaviors in an Epithelium Drive Collective Epithelial Cell Extrusion

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Organ development, like kidney and mammary gland formation, involves epithelial sheet folding and coordinated cell sorting.
• Mechanisms governing cell lineage sorting and tissue shaping during development are not fully understood.
• Tissues comprise diverse cell types with distinct biomechanical properties influencing their interactions.

Purpose of the Study:

• To investigate the role of atypical Protein Kinase C iota (aPKCi) in epithelial cell sorting and tissue organization.
• To explore how biomechanical interplay between different epithelial cell lineages contributes to tissue morphogenesis.
• To elucidate the mechanisms underlying 3D tissue formation from epithelial monolayers.

Main Methods:

• In vitro experiments using model epithelial cells.
• Analysis of differential expression of aPKCi and its effect on cell properties.
• Investigating forces generated by cell growth and confinement in heterogeneous epithelial monolayers.

Main Results:

• Differential aPKCi expression enhances epithelialization and triggers cell sorting by modulating mechanical properties.
• Forces from confined cell growth in heterogeneous monolayers promote collective cell extrusion.
• Emerging 3D structures, resembling spheroids and buds, arise from these processes.

Conclusions:

• aPKCi plays a crucial role in regulating cell mechanical properties for tissue shaping.
• Biomechanical interactions between distinct epithelial cell types are fundamental for organ development.
• This study provides insights into the physical mechanisms driving tissue morphogenesis and organoid formation.