Background
The multimerization of pro-thrombotic glycoprotein von Willebrand Factor (VWF) drives
the biosynthesis and determines the size and potential function of endothelial-specific
storage organelles, Weibel-Palade bodies (WPBs). VWF is the primary cargo of WPBs as
well as other vasoactive agents. The biogenesis of WPBs is dependent on the vascular
environment, which itself is modulated by factors such as shear stress and blood glucose
levels. Dysregulation of such environmental elements can result in pathological
phenotypes including elevated VWF levels particularly observed in diabetic patients. This
affects vascular function and endothelial cell (EC) physiology.
Aims
To develop assays for quantifying the effects of the diabetic microenvironment on the
formation and function of WPBs and VWF release in cells under physiological shear
stress
To establish the underlying molecular mechanisms involved.
Methods
An in vitro microfluidics system was used to develop models of diabetes mimicking
different aspects of the expected environment experienced in blood vessels including
glucose concentration and varying ECs. Cells were cultured under HSS conditions for
48hrs and then stimulated with an agonist to induce VWF exocytosis from WPBs.
Results
Exposure to elevated or oscillating glucose concentrations did not elicit many significant
effects on WPB numbers size or function in HUVECs. However, ECs derived from diabetic
patients displayed significant changes in the numbers and length of WPBs which may be a consequence of altered VWF structure.
Conclusions
The diabetic microenvironment may result in ECs developing a metabolic memory and
subsequently an altered pathogenic phenotype even when removed from a damaging
environment.
