Surface charge of endothelial cells estimated from electrophoretic mobility

Area of Science:

• Biophysics
• Cell Biology
• Biochemistry

Background:

• Endothelial cells form the inner lining of blood vessels.
• Understanding their surface charge is crucial for vascular health.
• Previous research has not fully elucidated the composition of endothelial cell surface charge.

Purpose of the Study:

• To estimate the surface charge density of endothelial cells.
• To compare endothelial cell surface charge to erythrocytes.
• To investigate factors influencing endothelial cell surface charge.

Main Methods:

• Cell electrophoresis was used to measure cell mobility.
• Endothelial cells from bovine pulmonary artery were cultured.
• Mobility was measured under varying ionic strength and calcium concentrations.

Main Results:

• Endothelial cell mobility was 0.74 +/- 0.08 (micron/s)/(V/cm), with a charge density of 2.62 x 10(4) esu/cm2.
• Erythrocyte mobility was 1.03 +/- 0.15 (micron/s)/(V/cm), with a charge density of 0.91 x 10(4) esu/cm2.
• Sialic acid removal did not affect endothelial cell mobility, but reduced erythrocyte mobility; mobility decreased with increased ionic strength or calcium concentration.

Conclusions:

• Endothelial cell surface charge is primarily determined by sulfated glycosaminoglycans.
• Unlike erythrocytes, sialic acid is not the main determinant of endothelial cell surface charge.
• Surface charge is sensitive to physiological changes in ionic strength and calcium levels.