Use of specialized resolving mediators to alleviate cold platelet storage lesion

BACKGROUND Cold-stored platelets are an attractive option for treatment of actively bleeding patients due to a reduced risk of septic complications and preserved hemostatic function compared to conventional room temperature-stored platelets. However, refrigeration causes increased platelet activation and aggregate formation. Specialized pro-resolving mediators (SPMs), cell signaling mediators biosynthesized from essential fatty acids, have been shown to modulate platelet function and activation. In this study, we sought to determine if SPMs could be used to inhibit cold-stored platelet activation. METHODS Platelets were collected from healthy donors (n = 4-7) and treated with SPMs (resolvin E1 [RvE1], maresin 1 [MaR1], and resolvin D2 [RvD2]) or vehicle (VEH; 0.1% EtOH). Platelets were stored without agitation in the cold and assayed on Days 0 and 7 of storage for platelet activation levels using flow cytometry, platelet count, aggregation response using impedance aggregometry, and nucleotide content using mass spectrometry. RESULTS Compared to VEH, SPM treatment inhibited GPIb shedding (all compounds), significantly reduced both PS exposure and activation of GPIIb/IIIa receptor (RvD2, MaR1), and preserved aggregation response to TRAP (RvD2, MaR1) after 7 days of storage. Similar to untreated cold-stored platelets, SPM-treated samples did not preserve platelet counts or block the release of P-Selectin. Nucleotide content was unaffected by SPM treatment in cold-stored platelets. CONCLUSIONS SPM treatment, particularly Mar1 and RvD2, led to reduced platelet activation and preserved platelet function after 7 days of storage in the cold. Future work is warranted to better elucidate the mechanism of action of SPMs on cold platelet function and activation.