1. Erythrocyte-Derived Microparticles Activate Pulmonary Endothelial Cells in a Murine Model of Transfusion
- Author
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Alex B. Lentsch, Rebecca Schuster, Alex L. Chang, Young Kim, Aaron P. Seitz, and Timothy A. Pritts
- Subjects
Male ,Erythrocytes ,Leukocyte adhesion molecule ,Intercellular Adhesion Molecule-1 ,Stimulation ,030204 cardiovascular system & hematology ,Critical Care and Intensive Care Medicine ,Article ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Cell-Derived Microparticles ,In vivo ,E-selectin ,medicine ,Animals ,Lung ,biology ,Chemistry ,Cell adhesion molecule ,Transendothelial and Transepithelial Migration ,Endothelial Cells ,030208 emergency & critical care medicine ,Molecular biology ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Emergency Medicine ,biology.protein ,E-Selectin ,Erythrocyte Transfusion ,Packed red blood cells - Abstract
Erythrocyte-derived microparticles (MPs) are sub-micrometer, biologically active vesicles shed by red blood cells as part of the biochemical changes that occur during storage. We hypothesized that MPs from stored red blood cells would activate endothelial cells. MPs from aged murine packed red blood cells (pRBCs) were isolated and used to treat confluent layers of cultured endothelial cells. Endothelial expression of leukocyte adhesion molecules, endothelial-leukocyte adhesion molecule-1 (ELAM-1) and intercellular adhesion molecule-1(ICAM-1), and inflammatory mediator, interleukin-6 (IL-6), was evaluated at 0.5, 6, 12, and 24 h of treatment. Healthy C57BL/6 mice were transfused with a MP suspension and lung sections were analyzed for adhesion molecules and sequestered interstitial leukocytes. Increased levels of ELAM-1 and ICAM-1 were found on cultured endothelial cells 6 h after MP stimulation (6.91 vs. 4.07 relative fluorescent intensity [RFI], P < 0.01, and 5.85 vs. 3.55 RFI, P = 0.01, respectively). IL-6 in cell culture supernatants was increased after 12 h of MP stimulation compared with controls (1.24 vs. 0.73 ng/mL, P = 0.03). In vivo experiments demonstrated that MP injection increased ELAM-1 and ICAM-1 expression at 1 h (18.56 vs. 7.08 RFI, P < 0.01, and 23.66 vs. 6.87 RFI, P < 0.01, respectively) and caused increased density of pulmonary interstitial leukocytes by 4 h of treatment (69.25 vs. 29.25 cells/high powered field, P < 0.01). This series of experiments supports our hypothesis that erythrocyte-derived MPs are able to activate pulmonary endothelium, leading to the pulmonary sequestration of leukocytes following the transfusion of stored pRBCs.
- Published
- 2017
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