Mechanical forces alter growth factor release by pleural mesothelial cells

Area of Science:

• Biomedical Engineering
• Cell Biology
• Pulmonary Medicine

Background:

• Mesothelial cells in the visceral pleura experience mechanical forces from lung expansion and movement.
• Understanding how these physical forces influence cellular functions is crucial for respiratory health.

Purpose of the Study:

• To investigate the effects of mechanical forces, specifically fluid shear stress and cyclic strain, on growth factor production by rat visceral pleura mesothelial (RVPM) cells.

Main Methods:

• RVPM cells were subjected to fluid shear stress using a perfused cell-covered bead system.
• Cyclic strain was applied to RVPM cells cultured on silicone elastomers using the Flexercell apparatus.
• The release of endothelin-1 (ET-1) and platelet-derived growth factor (PDGF) was quantified under mechanical stimulation.

Main Results:

• Fluid shear stress (5.2-15.7 dyn/cm2) increased ET-1 release by 2- to 5-fold compared to static conditions.
• Cyclic stretch (20% strain, 30 cycles/min) approximately doubled ET-1 secretion.
• While RVPM cells released significant PDGF, neither shear stress nor cyclic strain affected its release.

Conclusions:

• Physical forces, including fluid shear stress and cyclic strain, play a regulatory role in the production of growth factors by pleural mesothelial cells.
• ET-1 is a key growth factor whose release is modulated by mechanical stimuli in the pleura.
• These findings highlight the mechanosensitivity of mesothelial cells and their response to the physical environment of the lung.