Shear stress increases endothelial platelet-derived growth factor mRNA levels

Area of Science:

• Cardiovascular Biology
• Endothelial Cell Biology
• Molecular Biology

Background:

• Platelet-derived growth factor (PDGF) is a potent mitogen and vasoconstrictor.
• Endothelial cells play a crucial role in regulating blood flow and vascular adaptation.
• The effect of shear stress on PDGF expression in endothelial cells is not fully understood.

Purpose of the Study:

• To investigate the impact of shear stress on platelet-derived growth factor (PDGF) A and B chain mRNA levels in human umbilical vein endothelial cells (hUVEC).

Main Methods:

• Cultured hUVEC were exposed to varying levels of physiological shear stress (0-51 dyn/cm2).
• Platelet-derived growth factor (PDGF) A and B chain mRNA levels were quantified using quantitative analysis at different time points after shear stress onset.

Main Results:

• Physiological shear stress (16 dyn/cm2) significantly elevated both PDGF A and B mRNA levels in hUVEC, peaking at 1.5-2 hours.
• PDGF A mRNA showed a >10-fold increase, while PDGF B mRNA showed a 2-3 fold increase (P < 0.05).
• PDGF A mRNA levels increased with shear stress up to 6 dyn/cm2 and plateaued thereafter, while PDGF B mRNA levels exhibited a more complex, non-monotonic response to increasing shear stress.

Conclusions:

• Shear stress significantly upregulates PDGF A and B mRNA expression in endothelial cells.
• The findings suggest that shear stress-induced PDGF production by endothelial cells may contribute to the adaptation of blood vessels to blood flow.
• PDGF released from the endothelium may play a role in regulating blood flow in vivo.