Calcium signaling in platelets

Calcium signaling in platelets is a central regulatory mechanism that translates external stimuli into cellular responses such as shape change, granule secretion, and aggregation [Bergmeier & Stefanini, 2009; Varga-Szabo et al., 2009]. Upon activation of receptors like P2Y12, PAR1, or GPVI, phospholipase C (PLC) is activated, leading to the production of inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) [Gotru et al., 2018; Portland Press, 2014]. IP3 triggers the release of Ca2+ from the dense tubular system, while DAG and the depletion of internal stores promote Ca2+ entry from the extracellular space via channels like Orai1 and TRPC6 [Bergmeier & Stefanini, 2009; Frontiers, 2022]. This rise in cytosolic calcium is essential for the 'inside-out' activation of the integrin alpha-IIb/beta-3 and the subsequent formation of a stable thrombus [Blood, 2018; ResearchGate, 2017]. Because of its pivotal role in thrombosis, various components of the calcium signaling pathway are targeted by clinical antiplatelet agents to treat and prevent cardiovascular diseases [Frontiers, 2018; ResearchGate, 2012]. Drugs such as P2Y12 antagonists and COX-1 inhibitors effectively modulate this pathway to reduce the risk of myocardial infarction and stroke, although they also carry a risk of bleeding due to the inhibition of physiological hemostasis [Blood, 2018; ResearchGate, 2012].

Other names

Platelet calcium signalingIntracellular calcium signaling in plateletsCa2+ signaling in platelets

Antiplatelet drugs modulate calcium signaling by inhibiting upstream receptors (e.g., P2Y12, PAR1) or enzymes (COX-1), thereby preventing the generation of second messengers like IP3 and DAG that trigger calcium release and entry [Bergmeier & Stefanini, 2009; Varga-Szabo et al., 2009]. This suppression of intracellular calcium elevation inhibits downstream processes such as integrin activation and granule release [Gotru et al., 2018; Portland Press, 2014].