Oscillatory Disturbed Flow Enhances Inflammatory and Oxidative Stress Markers in Endothelial Cells

Area of Science:

• Biomedical Engineering
• Cell Biology
• Cardiovascular Research

Background:

• Hemodynamics, particularly shear stress, critically influence endothelial cell (EC) function.
• Abnormal blood flow dynamics (disturbed flows) can lead to endothelial dysfunction, contributing to atherosclerosis.
• Understanding flow-induced cellular changes is vital for cardiovascular disease research.

Purpose of the Study:

• To investigate the impact of normal (laminar) versus disturbed (oscillatory) blood flow on ECs in vitro.
• To explore the relationship between specific hemodynamic patterns and cellular pathways involved in oxidative stress and inflammation.
• To establish a microfluidic model for studying flow-associated vascular diseases.

Main Methods:

• Utilized a 2D cell culture perfusion system with immortalized human vascular endothelial cells (EA.hy926).
• Generated steady laminar flow (2 dynes/cm²) and disturbed oscillatory flow (0.5 dynes/cm²) for up to 24 hours.
• Analyzed gene expression (qPCR) and measured reactive oxygen species (ROS) generation.

Main Results:

• Oscillatory flow significantly increased proinflammatory markers (NFκ-B, COX-2) and apoptosis markers (C-Jun, CHOP) compared to static culture.
• Oscillatory flow decreased endothelial nitric oxide synthase (eNOS) and Endothelin-1 (ET-1) mRNA expression.
• Oscillatory flow markedly increased ROS generation in ECs compared to laminar flow and static conditions.
• Laminar flow showed minimal changes in gene expression and ROS compared to static culture.

Conclusions:

• Disturbed blood flow induces significant inflammatory and oxidative stress responses in endothelial cells.
• The microfluidic system effectively models hemodynamic forces relevant to vascular disease.
• Findings provide insights into molecular mechanisms underlying atherosclerosis and other flow-associated vascular conditions.