Low Shear in Short-Term Impacts Endothelial Cell Traction and Alignment in Long-Term

Area of Science:

• Vascular biology
• Mechanobiology
• Cellular biophysics

Background:

• Endothelial cells (ECs) in the vascular system experience fluid shear stress (FSS), a critical factor for vascular homeostasis.
• Dysfunctional responses to low or disturbed FSS contribute to cardiovascular diseases, but dynamic EC adaptation to FSS is poorly understood.

Approach:

• Investigated dynamic EC responses to brief low FSS using traction force microscopy (TFM) and a custom flow chamber.
• Analyzed human umbilical vein endothelial cells (HUVECs) traction force changes under varying shear stress conditions.

Key Points:

• Initial low FSS exposure significantly increased EC traction force over 10 hours, followed by a slow decrease.
• Immediate high FSS caused a rapid traction spike and subsequent reduction, distinct from low FSS response.
• Traction force direction and cell alignment revealed that initial shear experience dictates long-term endothelial behavior.

Conclusions:

• Short-lived low-shear stress experiences critically influence endothelial function.
• Early exposure to low FSS induces lasting changes in endothelial contractility and alignment.
• These findings have significant implications for understanding vascular health and cardiovascular disease development.