Proteomic profile of platelets during reconstitution of platelet counts after apheresis

Abstract

Purpose: Circulating platelets consist of subpopulations of different age. We designed an approach to remove platelets from circulation using platelet apheresis. We aimed to detect changes in the platelet proteome related to increased platelet turnover after apheresis to map candidate proteins, which may serve as markers of young platelets.

Experimental design: A healthy donor underwent three platelet apheresis procedures on three consecutive days. Blood was drawn at day 1 (baseline) and at days 3, 5, 7, 9, and 11 for the analysis of the platelet proteome using LC-ESI-MS/MS and 2D-DIGE.

Results: Among 1017 proteins identified by LC-ESI-MS/MS, 54 changed in quantity throughout the course of the study. Potential markers of young platelets were 40S ribosomal protein SA, COP9 signalosome complex subunit 5, and proteins involved in clathrin-mediated endocytosis signaling. Among 1036 protein spots observed by 2D-DIGE, 45 spots displayed changes in fluorescence intensity. Identified spots contained IQ motif containing GTPase activating protein 2, talin, moesin, myosin regulatory light chain 2, and coronin-1C.

Conclusions and clinical relevance: We provide the proof of principle that a combination of platelet apheresis and proteomic approaches enables identification of changes in the platelet proteome that are related to platelet de novo synthesis.

Keywords: Platelet age; Platelet apheresis; Platelet proteomics; Platelet turnover.