Radiation effects on circulating and endothelial cell interactions studied by quantitative real-time videomicroscopy

Area of Science:

• Biomedical Engineering
• Cell Biology
• Radiation Oncology

Background:

• Endothelial cells (EC) play a crucial role in vascular homeostasis.
• Radiation therapy can impact cellular function and interactions within the vasculature.
• Understanding radiation's effects on EC is vital for managing treatment side effects.

Purpose of the Study:

• To quantify the in vitro functional effects of irradiation on leukocyte and platelet interactions with endothelial cells (EC).
• To investigate these interactions in flowing whole blood under simulated physiological conditions.

Main Methods:

• Utilized a parallel-plate flow chamber to simulate physiological blood flow.
• Human microvascular lung endothelial cells (HMVEC-L) were exposed to 10 Gy irradiation.
• Leukocyte and platelet adhesion to EC in whole blood was measured using real-time videomicroscopy.

Main Results:

• Irradiation of EC significantly increased leukocyte rolling, velocity, and firm adhesion.
• Irradiated EC also showed enhanced platelet adhesion.
• The flow chamber accurately simulated physiological flow conditions.

Conclusions:

• In vitro irradiation of EC enhances pro-inflammatory and thrombogenic responses.
• These findings suggest a mechanism for radiation-induced vascular occlusion and fibrosis in vivo.
• EC dysfunction following irradiation is a key factor in radiation-induced vascular pathology.