Mechanical Regulation of Oral Epithelial Barrier Function

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Epithelial cell function is regulated by mechanical forces from the extracellular environment.
• Understanding how mechanical stress and matrix stiffness affect the cytoskeleton is crucial.
• New experimental models are needed to precisely challenge cell mechanics.

Purpose of the Study:

• To develop a novel epithelial tissue culture model, the 3D Oral Epi-mucosa platform.
• To investigate the role of mechanical cues in modulating the epithelial barrier function.
• To explore the effects of matrix stiffness and fibronectin on oral keratinocytes.

Main Methods:

• Developed a 3D Oral Epi-mucosa platform using oral keratinocytes on 3D fibrous collagen (Col) gels.
• Modulated gel stiffness by varying collagen concentration (1.5, 3, and 6 mg/mL) and adding fibronectin (FN).
• Applied low-level mechanical stress (0.1 kPa) and assessed epithelial leakiness, E-cadherin, and Zonula occludens-1 interactions.

Main Results:

• Intermediate stiffness collagen gels (3 mg/mL, 30 Pa) showed lower epithelial leakiness compared to soft (10 Pa) and stiff (120 Pa) gels.
• Matrix stiffness directly modulates epithelial barrier function.
• Fibronectin addition reversed barrier integrity by inhibiting interepithelial interactions via E-cadherin and Zonula occludens-1.

Conclusions:

• The 3D Oral Epi-mucosa platform serves as a novel in vitro system for studying mechanical cues in epithelial barriers.
• Findings highlight the critical role of matrix stiffness in maintaining mucosal barrier integrity.
• The platform can be used to identify mechanisms and targets for mucosal diseases.