Protein changes occurring during storage of platelet concentrates

Abstract

The changes in thrombocyte proteins during 22 degrees C storage of platelet concentrates (PC) were studied. To prepare a reference protein "map" of stored PC, platelet samples were taken on days 1, 7, and 21. The platelet proteins were separated by isoelectric focusing (first-dimension) followed by second-dimension polyacrylamide gradient gel electrophoresis with sodium dodecylsulfate (2D). The silver-stained gels were analyzed by computer to obtain a composite map of stored PC proteins. The pattern seen on day 1 changed during 7 days of storage, with 30 proteins increasing or decreasing in spot density. In general, the spot density for lower-molecular-weight proteins increased, whereas that for higher-molecular-weight proteins decreased. Membrane proteins of intact fresh and stored platelets were labeled with 3H using sodium metaperiodate-[3H]NaBH4 and with 125I using lactoperoxidase-H2O2. A comparison on the fluorographs of 2D gels of [3H]NaBH4-labeled platelet proteins showed several protein spots in the stored Day 7 sample that had not been seen in the Day 1 sample. Similarly, for the autoradiographs, several 125I-labeled proteins detected in Day 7 PC were not seen in the Day 1 samples. The results provide evidence that platelet proteins are altered during PC storage and that these changes involve platelet membrane proteins.

Platelet proteomics

“…Indeed, several pre-analytical factors may modify platelet structure and function and consequently the final proteomic profile. These factors include the recent administration of drugs interfering with platelet function such as aspirin or non-steroid anti-inflammatory drugs (Patrono & Rocca, 2009), quick isolation of platelets after blood collection (Thon, Schubert, & Devine, 2008a) or, in case of platelet concentrate bags, their storage (Snyder et al, 1987) and age (Egidi et al, 2010) and temperature of the platelet suspension (ideally at 378C) These isolation features may induce protein modifications, such as glycosylations (Wandall et al, 2008), and thus bias the results. This is of high importance when platelets are isolated from medical blood transfusion products.…”

“…Indeed, apheresis or whole blood units used in research settings are usually out-ofdate. In these conditions, storage duration or temperature are not driven by the experimental workflow, but by transfusion guidelines and preliminary tests should be done to ensure the quality of the platelet suspension (Snyder et al, 1987;Thon, Schubert, & Devine, 2008a;Thon et al, 2008b). For instance, it has been shown by Hoffmeister et al (2003a,b) that cooling platelets induces a rapid clearance of the platelets, which can be of high importance in case of transfusion, but also for platelet functional studies from medical blood product.…”

“…They could identify proteins and glycoproteins by comparison with purified samples or plasma proteins. The same method was used by Snyder to define the protein alterations due to platelets concentrate storage (Snyder et al, 1987). Researchers analyzed samples from platelet concentrates on days 1, 7, and 21 by 2-DE gels, using computer-assisted comparison of a silverstaining coloration, a fluorescent and radioactive labeling.…”

Biomarker Analysis of Stored Blood Products: Emphasis on Pre-Analytical Issues

“…Protein analysis of platelets during storage was first achieved in the end of the 1980s by identifying variation in actin [56,57]. However, actin polymerization is linked to the method used in the preparation of PCs and it has been shown that this process is partially reversible after 1 day of storage [58], which is highlighting the implication of pre-analytics in biomarker discovery.…”

Effect of Prestorage Leukocyte Reduction on Proteins of Platelets Obtained by Apheresis

“…modifications of platelet proteins due to storage were de scribed using the two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) [22], In this study we compared non-filtered platelet concen trates (NFPCs) and filtered platelet concentrates (FPCs) during a storage period of 7 days. GPIb, GPIIb/IIIA and GMP-140 platelet surface expression was assessed using specific monoclonal antibodies (MoAb) and flow cytom etry, platelet responses to thrombin and ristocetin were studied by aggregometry and platelet protein patterns were analyzed by 2D-PAGE.…”