Hematological abnormalities and altered vascular permeability are frequently encountered in Dengue virus infected patients, but the mechanisms that alter platelet-endothelium interactions remain incompletely understood. The DENV NS1 protein has been implicated in adverse disease outcomes. In the present study the role of NS1 protein in affecting the expression of vWF and platelet adhesion properties of endothelial cells was studied in vitro. The results suggest that vWF is down regulated in cultured endothelial cells 6 and 24 h after exposure with increase in vWF levels in culture supernatants at corresponding time points. Ultrastructural studies showed distinct evidence of endothelial cell activation morphology and degranulation of Weibel-Palade bodies in NS1 exposed cells that also showed increased platelet activation physiology. The findings suggest that changes in vWF production and secretion may be induced in endothelial cells exposed to DENV NS1 protein; and play a role in bleeding complications of severe DENV disease.
Keywords: Dengue virus; Endothelial cells; NS1; von Willebrand factor.