Human dermal microvascular endothelial cell morphological response to fluid shear stress

Area of Science:

• Cardiovascular Biology
• Cell Biology
• Biophysics

Background:

• Endothelial cells form the vasculature and sense blood flow via fluid shear stress.
• The response of endothelial cells to shear stress varies by cell type.
• Understanding these responses is crucial for vascular health research.

Purpose of the Study:

• To characterize the morphological response of human dermal microvascular endothelial cells (HMEC-1) to varying levels of fluid shear stress.
• To analyze changes in both cellular and nuclear morphology over time under different shear stress conditions.

Main Methods:

• Cultured HMEC-1 monolayers were subjected to steady, laminar, unidirectional fluid shear stress (0.3, 16, or 32 dyn/cm²).
• Live-cell imaging was used to capture nuclear and cellular morphology hourly over 72 hours.
• Quantitative analysis of cell and nuclear area, elongation, alignment, and orientation was performed.

Main Results:

• Increasing fluid shear stress induced some cell elongation and alignment, but this effect diminished over time.
• Cellular and nuclear area changes were dependent on both shear stress magnitude and duration.
• Distinct morphological trends emerged at shear stress levels above and below 16 dyn/cm².
• Nuclear orientation remained independent of the applied fluid shear stress magnitude.

Conclusions:

• HMEC-1 exhibit a complex, time-dependent, and shear stress-dependent morphological response.
• The study highlights differential responses in cell area versus elongation/alignment.
• Nuclear orientation is less sensitive to shear stress magnitude compared to other morphological parameters in HMEC-1.