Investigation of peri/epicellular protein disulphide isomerase as a novel regulator of the platelet-endothelium interaction in normoglycaemia and Diabetes

Abstract

Diabetes is a chronic and epidemic disease with high socio-economical cost worldwide, being characterized by increased risk of cardiovascular disease (CVD) and thromboembolic event. Upon endothelial dysfunction, platelets bind to endothelial cells to precipitate thrombus formation in a process that is not fully understood. Specifically, it is still unclear which surface proteins regulate platelet-endothelium interaction. In this regard, our lab has shown that peri/epicellular (pec) protein disulphide isomerase A1 (pecPDI) influences adhesion and migration of vascular cells. Therefore we hypothesize that pecPDI may regulate adhesion molecules on the surface of endothelial cells and platelets that influence the binding of these cells in physiological and pathological settings. Moreover, previous evidence suggests PDI is involved in Diabetes, therefore the impact of pecPDI will be assessed in diabetic mice in vivo and hyperglycaemic cells in vitro. Our main goal is to examine if pecPDI regulates platelet-endothelium interaction in normoglycaemia and Diabetes. Specifically, we will assess if pecPDI inhibition or genetic deletion of PDI affects expression levels of adhesion proteins, such as integrin beta 3, platelet and endothelial cell adhesion molecule 1 (PECAM-1), intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), in hyperglycaemic endothelial cells in vitro; which adhesion molecules are targeted by pecPDI and how does pecPDI influence platelet-endothelium interaction in normo and Hyperglycaemia. Finally we will assess the importance of PDI to modulate platelet-endothelium interaction and thrombus formation in diabetic mice using intravital microscopy. Our lab is uniquely positioned to study how pecPDI associates with adhesion molecules, given the extensive techniques developed throughout decades of intensive scientific output. Altogether, the elucidation of novel molecules regulated by pecPDI, as well as mechanistic basis for platelet-endothelium interaction in normoglycaemia and Diabetes will expand the relevance of pecPDI to cell function and potentially lead to novel targets to treat and prevent thrombotic diseases in Diabetes. (AU)