Rumjantseva Viktoria, Grewal Prabhjit K, Wandall Hans H, Josefsson Emma C, Sørensen Anne Louise, Larson Göran, Marth Jamey D, Hartwig John H, Hoffmeister Karin M
Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
Nat Med. 2009 Nov;15(11):1273-80. doi: 10.1038/nm.2030. Epub 2009 Sep 27.
Rapid chilling causes glycoprotein-Ib (GPIb) receptors to cluster on blood platelets. Hepatic macrophage beta(2) integrin binding to beta-N-acetylglucosamine (beta-GlcNAc) residues in the clusters leads to rapid clearance of acutely chilled platelets after transfusion. Although capping the beta-GlcNAc moieties by galactosylation prevents clearance of short-term-cooled platelets, this strategy is ineffective after prolonged refrigeration. We report here that prolonged refrigeration increased the density and concentration of exposed galactose residues on platelets such that hepatocytes, through Ashwell-Morell receptor binding, become increasingly involved in platelet removal. Macrophages rapidly removed a large fraction of transfused platelets independent of their storage conditions. With prolonged platelet chilling, hepatocyte-dependent clearance further diminishes platelet recovery and survival after transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold.
快速冷却会导致糖蛋白 Ib（GPIb）受体在血小板上聚集。肝脏巨噬细胞的β2整合素与这些聚集体中的β-N-乙酰葡糖胺（β-GlcNAc）残基结合，会导致输血后急性冷却的血小板被迅速清除。尽管通过半乳糖基化封闭β-GlcNAc部分可防止短期冷却血小板的清除，但在长期冷藏后该策略无效。我们在此报告，长期冷藏会增加血小板上暴露的半乳糖残基的密度和浓度，从而使肝细胞通过阿什韦尔-莫雷尔受体结合，越来越多地参与血小板清除。巨噬细胞会迅速清除大部分输血后的血小板，而与它们的储存条件无关。随着血小板长期冷却，肝细胞依赖性清除会进一步降低输血后血小板的回收率和存活率。抑制β2整合素和阿什韦尔-莫雷尔受体对冷却血小板的清除作用，可能为在低温下储存血小板提供一种潜在的简单方法。
