Endothelial activation by platelets from sickle cell anemia patients

• Published in: PloS one 2014-02, Vol.9 (2), p.e89012-e89012
• Main Authors: Proença-Ferreira, Renata, Brugnerotto, Ana Flávia, Garrido, Vanessa Tonin, Dominical, Venina Marcela, Vital, Daiana Morelli, Ribeiro, Marilene de Fátima Reis, dos Santos, Melissa Ercolin, Traina, Fabíola, Olalla-Saad, Sara T, Costa, Fernando Ferreira, Conran, Nicola
• Format: Article
• Language: English
• Subjects: Adenosine; Adhesion; Adolescent; Adult; Analysis; Anemia; Anemia, Sickle Cell - genetics; Anemia, Sickle Cell - metabolism; Anemia, Sickle Cell - pathology; Bioavailability; Biology; Blood; Blood platelets; Blood Platelets - metabolism; Blood Platelets - pathology; Blood Platelets - secretion; Cell activation; Cell Adhesion; Cell culture; Children & youth; Coculture Techniques; Cytokines; Cytometry; E-selectin; E-Selectin - genetics; E-Selectin - metabolism; Endothelial cells; Endothelium; Female; Flow cytometry; Gene expression; Gene Expression Regulation; Gene flow; Hematology; Human Umbilical Vein Endothelial Cells - cytology; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Inflammation; Inserts; Intercellular adhesion molecule 1; Intercellular Adhesion Molecule-1 - genetics; Intercellular Adhesion Molecule-1 - metabolism; Interleukin 8; Interleukin-1beta - biosynthesis; Interleukin-1beta - secretion; Interleukin-8 - biosynthesis; Interleukin-8 - secretion; Ligands; Male; Medicine; Middle Aged; NF-kappa B - antagonists & inhibitors; NF-kappa B - genetics; NF-kappa B - metabolism; NF-κB protein; Nitriles - pharmacology; P-selectin; P-Selectin - genetics; P-Selectin - metabolism; Platelet Glycoprotein GPIIb-IIIa Complex - genetics; Platelet Glycoprotein GPIIb-IIIa Complex - metabolism; Platelets; Primary Cell Culture; Pulmonary hypertension; Sickle cell anemia; Sickle cell disease; Signal transduction; Signal Transduction - genetics; Signaling; Sulfones - pharmacology; Tumor necrosis factor-TNF; Umbilical vein
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0089012

Sickle cell anemia (SCA) is associated with a hypercoagulable state. Increased platelet activation is reported in SCA and SCA platelets may present augmented adhesion to the vascular endothelium, potentially contributing to the vaso-occlusive process. We sought to observe the effects of platelets (PLTs) from healthy control (CON) individuals and SCA individuals on endothelial activation, in vitro. Human umbilical vein endothelial cells (HUVEC) were cultured, in the presence, or not, of washed PLTs from CON or steady-state SCA individuals. Supernatants were reserved for cytokine quantification, and endothelial adhesion molecules (EAM) were analyzed by flow cytometry; gene expressions of ICAM1 and genes of the NF-κB pathway were analyzed by qPCR. SCA PLTs were found to be more inflammatory, displaying increased adhesive properties, an increased production of IL-1β and a tendency towards elevated expressions of P-selectin and activated αIIbβ3. Following culture in the presence of SCA PLTs, HUVEC presented significant augmentations in the expressions of the EAM, ICAM-1 and E-selectin, as well as increased IL-8 production and increased ICAM1 and NFKB1 (encodes p50 subunit of NF-κB) gene expressions. Interestingly, transwell inserts abolished the effects of SCA PLTs on EAM expression. Furthermore, an inhibitor of the NF-κB pathway, BAY 11-7082, also prevented the induction of EAM expression on the HUVEC surface by SCA PLTs. In conclusion, we find further evidence to indicate that platelets circulate in an activated state in sickle cell disease and are capable of stimulating endothelial cell activation. This effect appears to be mediated by direct contact, or even adhesion, between the platelets and endothelial cells and via NFκB-dependent signaling. As such, activated platelets in SCD may contribute to endothelial activation and, therefore, to the vaso-occlusive process. Results provide further evidence to support the use of anti-platelet approaches in association with other therapies for SCD.