Transfer of Alarmins from Neutrophils to Platelets after Acute Myocardial Infarction

ABSTRACT: Platelets are central to the pathophysiology of myocardial infarction (MI). How the platelet proteome is altered during MI is unknown. We sought to describe changes in the platelet proteome at the time of MI and identify potential mechanisms. Platelets from patients experiencing ST-elevation myocardial infarction (STEMI) before and 3 days after treatment (n= 30), and a matched cohort of patients with severe stable coronary artery disease(CAD) prior to and 3 days after coronary artery bypass grafting (CABG, n=25) underwent quantitative proteomic analysis. Elevations of the alarmins S100A8 and S100A9 were detected at the time of STEMI compared with stable CAD (S100A8, FC = 2.00, FDR = 0.05; S100A9, FC = 2.28, FDR = 0.005). During STEMI, S100A8 mRNA and protein levels were correlated in platelets (R = 0.46, p = 0.012). To determine if protein synthesis occurs, activated platelets were incubated with 13C-labelled amino acids for 24 hours and analyzed by mass spectrometry. No incorporation was detected, consistent with the notion that protein synthesis in platelets is not a major contributor to the platelet proteome. Platelet abundance of S100A8 and A9 was strongly correlated with neutrophil abundance at the time of STEMI. When isolated platelets and neutrophils were co-incubated under quiescent and TRAP-6 activated conditions, release of S100A8 from neutrophils resulted in uptake of S100A8 by platelets. Leukocyte-to-platelet protein transfer, rather than protein synthesis, may occur in a thromboinflammatory environment such as STEMI, representing a potential new contributor in the innate immune pathogenesis of STEMI.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Platelet, Blood

SUBMITTER: Xiaoke Yin  

LAB HEAD: Manuel Mayr

PROVIDER: PXD024186 | Pride | 2023-11-15

REPOSITORIES: Pride