Discovery of platelet glycoprotein VI receptor antagonists and their neuroprotective activity: an in silico, in vitro, and in vivo study

Abstract

The present study utilized a drug repurposing approach to identify potential GPVI receptor antagonists among FDA-approved drugs. Computational and molecular dynamics simulations revealed that adapalene and ranolazine exhibit strong binding affinities to GPVI receptors and stabilize GPVI proteins, respectively. Both compounds inhibited collagen-induced platelet aggregation, evidenced by the suppression of Syk tyrosine kinase expression, a marker of platelet activation, via GPVI stimulation, as confirmed through flow cytometry analysis. Further analysis using circular dichroism and Raman spectroscopy indicated that collagen exposure induced conformational changes in the α-helical domains of platelets, which were stabilized upon treatment with adapalene and ranolazine. Moreover, thrombotic events can lead to cerebral cell death due to hypoxia, which may be mitigated by neuroprotective compounds. Adapalene and ranolazine were assessed for their neuroprotective capabilities. The results showed that these compounds exhibited neuroprotective effects in SHSY5Y neuroblastoma cells subjected to oxygen–glucose deprivation/reperfusion (OGD/R) injury, reducing HIF-1α expression, ROS production, lipid peroxidation, and caspase-3 levels, while also improving mitochondrial membrane potential and glutathione levels. Acridine orange and propidium iodide staining studies further confirmed a decrease in apoptosis. In the FeCl<inf>3</inf>-induced carotid artery thrombosis model, ranolazine effectively inhibited platelet aggregation by modulating GPVI receptor activity, reducing intracellular calcium levels, and enhancing cAMP signaling. It also suppressed critical platelet activation mediators, including COX-1, TXB<inf>2</inf>, and PGE<inf>2</inf>, thereby mitigating thrombus formation. Collectively, these results suggest that adapalene and ranolazine may serve as multimodal therapeutic agents with the potential to treat both thrombotic and neurological diseases. Future studies focusing on the adapalene and ranolazine molecular mechanisms, bleeding risk, dose titration, and long-term safety while managing thrombotic disorders have to be investigated. © King Abdulaziz City for Science and Technology 2025.