Objective: Inflammatory conditions contribute to increased expression of various activity markers in platelets and endothelial cells, leading to atherosclerotic changes in the vascular wall. The objective of this study was to investigate possible protective effects of 1α,25-dihydroxyvitamin D3 in an endothelial cell model.
Methods: After a 24-hour incubation with 1α,25-dihydroxyvitamin D3, human umbilical vein endothelial cells were stimulated with lipopolysaccharide (LPS) and incubated in direct contact with platelets. The expression of CD40L and CD62P in platelets, the expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1 (VCAM-1), the urokinase receptor uPAR and membrane type 1 matrix metalloproteinase (MT1-MMP) in endothelial cells and endothelial cell reactive oxygen species generation were measured by flow cytometry. Endothelial nitric oxide synthase was analyzed by Western blot.
Results: The increased expression of VCAM-1 and MT1-MMP in endothelial cells by proinflammatory stimulation with LPS and by direct contact with activated platelets was significantly reduced through preincubation with 1α,25-dihydroxyvitamin D3. Platelets in direct contact with preincubated endothelial cells showed significantly reduced CD62P expression when compared to platelets incubated with untreated endothelial cells.
Conclusions: 1α,25-Dihydroxyvitamin D3 attenuates platelet activation and the expression of VCAM-1 and MT1-MMP in human endothelial cells and could have early therapeutic relevance in atherosclerotic diseases.
Copyright © 2011 S. Karger AG, Basel.