Force-exerting perpendicular lateral protrusions in fibroblastic cell contraction.

Area of Science:

• Cell biology
• Biophysics
• Biomaterials science

Background:

• Fibroblast activation and extracellular matrix (ECM) fiber alignment are critical in fibrosis and cancer.
• The feedback loop between fibroblasts and ECM is poorly understood.
• Cancer-associated desmoplasia involves significant ECM remodeling.

Purpose of the Study:

• To elucidate the mechanism by which fibroblasts interact with and remodel aligned ECM fibers.
• To identify novel cellular structures involved in fibroblast-ECM force transmission.
• To understand the role of these structures in fibrosis and cancer progression.

Main Methods:

• Utilized 3D fiber networks as force sensors to study fibroblast behavior.
• Investigated cell extensions named 'twines' and their evolution into 3D perpendicular lateral protrusions (3D-PLPs).
• Manipulated ECM geometry to assess the impact on 3D-PLP formation and function.

Main Results:

• Identified 3D perpendicular lateral protrusions (3D-PLPs) originating from 'twines'.
• Demonstrated that 3D-PLPs increase fibroblast contractility and force on aligned fibers.
• Confirmed that anisotropic fibrous environments promote 3D-PLP formation and function, linking them to desmoplastic expansion.

Conclusions:

• 3D-PLPs are key structures mediating fibroblast force exertion on aligned ECM fibers.
• This mechanism contributes to pathological conditions like fibrosis and cancer-associated desmoplasia.
• Controlling ECM architecture influences fibroblast behavior and pathological outcomes.