The Platelet P2 Receptors

QSAR, structure-based pharmacophore modelling and biological evaluation of novel platelet ADP receptor (P2Y12) antagonist

P2Y12 has a key role in platelet aggregation and thrombus formation via an ADP-induced platelet activation mechanism. Recently, P2Y12 antagonists have become of great interest in the clinical management of antithrombotic therapy. In light of this, we explored the pharmacophoric space of P2Y12 using structure-based pharmacophore modelling. Subsequently, genetic algorithm and multiple linear regression analyses were conducted to select the best combination of physicochemical descriptors and pharmacophoric models to create useful predictive quantitative structure-activity relationship (QSAR) equation (r 2 = 0.9135, r (adj) 2 = 0.9147, r (PRESS) 2 = 0.9129, LOF = 0.3553). One pharmacophoric model emerged in the QSAR equation and was validated by analysing receiver operating characteristic (ROC) curves. The model was then used to screen 200 000 compounds from the National Cancer Institute (NCI) database. The top-ranked hits were in vitro tested, where their IC50's range between 4.20 to 35.00 μM when measured via the electrode aggregometry assay. Whilst, the VASP phosphorylation assay showed 29.70% platelet reactivity index for NSC618159, which is superior to that of ticagrelor.

Purinergic receptor ligands: the cytokine storm attenuators, potential therapeutic agents for the treatment of COVID-19

The coronavirus disease-19 (COVID-19), at first, was reported in Wuhan, China, and then rapidly became pandemic throughout the world. Cytokine storm syndrome (CSS) in COVID-19 patients is associated with high levels of cytokines and chemokines that cause multiple organ failure, systemic inflammation, and hemodynamic instabilities. Acute respiratory distress syndrome (ARDS), a common complication of COVID-19, is a consequence of cytokine storm. In this regard, several drugs have been being investigated to suppress this inflammatory condition. Purinergic signaling receptors comprising of P1 adenosine and P2 purinoceptors play a critical role in inflammation. Therefore, activation or inhibition of some subtypes of these kinds of receptors is most likely to be beneficial to attenuate cytokine storm. This article summarizes suggested therapeutic drugs with potential anti-inflammatory effects through purinergic receptors.

Involvement of P2Y12 receptors in an NTG-induced model of migraine in male mice

BACKGROUND AND PURPOSE

P2Y₁₂ receptors (P2Y₁₂ Rs) are known to regulate different forms of pain and inflammation. In this study we investigated the participation of P2Y₁₂ Rs in an animal model of migraine.

EXPERIMENTAL APPROACH

We tested the effect of the centrally administered selective P2Y₁₂ R antagonist PSB-0739, and P2Y₁₂ R gene deficiency in acute nitroglycerin (NTG)-treated mice. Additionally, platelet depletion was used to investigate the role of platelet P2Y₁₂ Rs during migraine-like pain.

KEY RESULTS

NTG induced sensory hypersensitivity of C57BL/6 wild-type (P2ry12^+/+ ) mice, accompanied by an increase in c-fos and CGRP expression in the upper cervical spinal cord (C1-C2) and trigeminal nucleus caudalis (TNC). Similar changes were also observed in P2Y₁₂ R gene-deficient (P2ry12^-/- ) mice. Prophylactic intrathecal application of PSB-0739 reversed thermal hyperalgesia and head grooming time in wild-type mice but had no effect in P2ry12^-/- mice; furthermore, it was also effective when applied as a post-treatment. PSB-0739 administration suppressed the expression of c-fos in C1-C2 and TNC, and decrease C1-C2 levels of dopamine and serotonin in wild-type mice. NTG treatment itself did not change adenosine diphosphate (ADP)-induced platelet activation measured by CD62P upregulation in wild-type mice. Platelet depletion by anti-mouse CD41 antibody and clopidogrel attenuated NTG-induced thermal hypersensitivity and head grooming time in mice.

CONCLUSION AND IMPLICATIONS

Taken together, our findings show that acute inhibition of P2Y₁₂ Rs alleviates migraine-like pain in mice, by modulating the expression of c-fos, and platelet P2Y₁₂ Rs might contribute to this effect. Hence, it is suggested that the blockade of P2Y₁₂ Rs may have therapeutic potential against migraine.