Rho/ROCK mechanosensor in adipocyte stiffness and traction force generation

Area of Science:

• Cellular mechanics
• Adipocyte biology
• Biophysics

Background:

• Adipose cell interactions with their mechanical environment influence adipogenesis and function.
• Cellular mechanics are a key mediator of these interactions.
• Understanding these mechanical properties is crucial for adipose tissue research.

Purpose of the Study:

• To investigate the role of Rho/ROCK signaling in regulating adipose cell mechanical properties.
• To quantify the stiffness and traction forces of preadipocytes and differentiated adipocytes.
• To explore how Rho/ROCK affects actin cytoskeletal contractility and cell mechanics.

Main Methods:

• Atomic Force Microscopy (AFM) to measure cellular Young's modulus (stiffness).
• Traction Force Microscopy (TFM) to assess cellular traction forces.
• Immunofluorescent imaging to visualize actin filament formation.
• Pharmacological manipulation using Rho activator (CN01) and ROCK inhibitor (Y-27632).

Main Results:

• ROCK inhibition reduced cell stiffness, while Rho activation increased it in both cell types.
• Differentiated adipocytes exhibited higher stiffness but lower traction forces than preadipocytes.
• Rho/ROCK signaling significantly modulated actin stress fibers, impacting cell mechanics.
• Lipid droplet accumulation in adipocytes may disrupt force transmission, reducing traction force-cell area correlation.

Conclusions:

• Rho/ROCK signaling is a critical regulator of adipose cell mechanics.
• Cellular stiffness and traction forces differ between preadipocytes and adipocytes, influenced by Rho/ROCK.
• These findings provide a foundation for studying adipocyte mechanotransduction in adipogenesis and tissue remodeling.