Tissue-engineered arterial intima model exposed to steady wall shear stresses

Area of Science:

• Cardiovascular biology
• Mechanobiology
• Cellular biomechanics

Background:

• The arterial intima experiences continuous pulsatile wall shear stress (WSS) from blood flow.
• The specific contribution of smooth muscle cells (SMC) to endothelial cell (EC) responses to WSS is not fully understood.

Purpose of the Study:

• To investigate the role of SMCs in the EC response to WSS using a novel co-culture model.
• To compare the effects of WSS on ECs in a co-culture system versus a monolayer system.

Main Methods:

• Developed a co-culture model of ECs on SMCs mimicking arterial intima structure.
• Exposed both co-culture and EC monolayer models to steady flow-induced WSS (up to 24 dyne/cm² for 60 min).
• Quantified alterations in F-actin and VE-cadherin using confocal imaging and flow cytometry.

Main Results:

• Both models maintained high confluency post-WSS exposure.
• ECs in the monolayer showed greater F-actin polymerization compared to co-cultures, suggesting SMCs aided in resisting WSS.
• SMCs in co-culture maintained a contractile phenotype under high WSS, indicating a more physiological response.

Conclusions:

• SMCs actively contribute to the arterial intima's ability to withstand flow-induced WSS.
• The co-culture model provides a more physiologically relevant platform for studying intima mechanobiology.
• Understanding SMC-EC interactions under WSS is crucial for cardiovascular health.