High glucose enhances inflammation-driven platelet adhesion to endothelial cells in vitro.

Endothelial and platelet dysfunction are central to vascular disease development. We established a simplified, reproducible 96-well plate model to assess platelet adhesion to endothelial cells under conditions mimicking in vitro endothelial dysfunction and platelet hyperactivation. Human aortic endothelial cells (HAEC) were treated with tumour necrosis factor-alpha (TNF-α, 20-50 ng/mL) and/or high glucose levels (30 mM) to replicate in vitro the states of inflammation and hyperglycaemia. Treated HAEC were then exposed to platelets from healthy volunteers. In some experiments, platelets were treated with tirofiban, a GP IIb/IIIa inhibitor, before HAEC exposure. Platelet adhesion was evaluated by fluorescence, transmission, and scanning electron microscopy. Conditions showing significant effects were subsequently confirmed using a microfluidic device under high shear conditions. TNF-α stimulation significantly increased platelet adhesion to HAEC. This was accompanied by morphological changes indicative of activation. High glucose alone had no significant effect but, when combined with TNF-α, it synergistically enhanced platelet adhesion under both static and dynamic flow conditions. Interestingly, adhesion was prevented by platelet pretreatment with tirofiban. This study demonstrates the utility of a straightforward experimental in vitro setup that allows for mechanistic studies regarding platelet-endothelial interaction. By combining simplicity with reproducibility, the model offers a valuable tool for investigating platelet-endothelium interactions. It also serves as a preclinical platform for evaluating therapeutic interventions aimed at reducing thrombotic risk in conditions of inflammation and hyperglycaemia.