Myofibroblasts slow down defect recombination dynamics in mixed cell monolayers

Area of Science:

• Cell Biology
• Biophysics
• Tissue Engineering

Background:

• Cellular organization and mechanotransduction are vital for tissue development, with dysregulation linked to diseases like fibrosis.
• Overactive myofibroblasts drive fibrosis, but their effect on collective cell ordering is not well understood.
• Topological defects in cell alignment may act as mechanical centers, influencing tissue behavior.

Purpose of the Study:

• To investigate how myofibroblasts influence defect dynamics and cellular ordering in co-cultured fibroblast-myofibroblast monolayers.
• To explore the role of cell-cell interactions and substrate topography in modulating cellular organization.
• To understand the relationship between myofibroblast presence, topological defects, and mechanical stress.

Main Methods:

• Co-culture of fibroblasts and myofibroblasts in monolayers.
• Analysis of cellular ordering and topological defect dynamics.
• Experiments on both flat and microgrooved surfaces.
• Immunofluorescence staining to assess mechanotransduction pathways.

Main Results:

• Increasing myofibroblast fraction enhanced disorder and slowed defect recombination.
• Higher myofibroblast concentrations reduced alignment on microgrooved surfaces, indicating combined mechanosensing and cell-cell interactions.
• Myofibroblasts preferentially localized at -1/2 defects, while fibroblasts localized at +1/2 defects.
• Myofibroblast localization at -1/2 defects increased local friction, impeding defect mobility and contributing to slowed dynamics.

Conclusions:

• Myofibroblasts significantly alter collective cell ordering and dynamics in mixed monolayers.
• Preferential localization of myofibroblasts at specific topological defects is a key mechanism affecting defect mobility and tissue mechanics.
• Findings provide insights into the interplay between cell phenotype, topological defects, and mechanotransduction in tissue morphogenesis and fibrosis.