Temsirolimus Sensitive Stimulation of Platelet Activity, Apoptosis and Aggregation by Collagen Related Peptide

The mammalian target of rapamycin (mTOR) inhibitor temsirolimus stimulates apoptosis of tumor cells and is thus therapeutically used for the treatment of diverse malignancies. On the other hand, temsirolimus has been shown to protect against apoptosis of hippocampal neurons. Similar to nucleated cells, blood platelets may enter suicidal death characterized by cell shrinkage and cell membrane scrambling. Platelet apoptosis is frequently preceded by Ca2+ entry, degranulation, integrin activation and stimulation of caspases. Those events could be triggered by collagen related peptide (CRP). The present study explored whether treatment of platelets with temsirolimus modifies platelet activation, caspase activity, platelet shrinkage, and phosphatidylserine abundance.