Insulin Resistance May Contribute to Upregulation of Adhesion Molecules on Endothelial Cells in Psoriatic Plaques

Psoriasis primarily affects the skin, but also has a systemic dimension and is associated with severe comorbidities. Since endothelial cells play an important role in psoriasis as well as in the development of cardiovascular comorbidities, we investigated whether a common mechanism, namely cytokine-induced insulin resistance, underlies both pathologies. Activation of the insulin pathway was studied in psoriatic skin and dermal endothelial cells. Expression of adhesion molecules was assessed by flow cytometry, as well as their biological function in flow chamber experiments. The phosphorylation status of Akt, a central kinase in the insulin pathway, suggests that endothelial cells within psoriatic plaques are rendered insulin resistant by pro-inflammatory cytokines. Insulin counteracts the expression of adhesion molecules, but has limited effects on interactions between T cells and endothelial cells. Pro-inflammatory cytokines induce insulin resistance in endothelial cells, which may contribute to the development of the inflammatory infiltrate in psoriasis.