title: Endothelial activation by platelets from sickle cell anemia patients.
abstract: 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.
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Proença-Ferreira
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Ana Flávia
authors.initials: AF
authors.lastname: Brugnerotto
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Vanessa Tonin
authors.initials: VT
authors.lastname: Garrido
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Venina Marcela
authors.initials: VM
authors.lastname: Dominical
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Daiana Morelli
authors.initials: DM
authors.lastname: Vital
authors.affiliation: Children's Center for Hematologic Investigations, Dr. Domingos A. Boldrini, Campinas, Brazil.
authors.forename: Marilene de Fátima Reis
authors.initials: Mde F
authors.lastname: Ribeiro
authors.affiliation: Children's Center for Hematologic Investigations, Dr. Domingos A. Boldrini, Campinas, Brazil.
authors.forename: Melissa Ercolin
authors.initials: ME
authors.lastname: dos Santos
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil ; Department of Internal Medicine, University of São Paulo at Riberão Preto Medical School, Riberão Preto, Brazil.
authors.forename: Fabíola
authors.initials: F
authors.lastname: Traina
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Sara T
authors.initials: ST
authors.lastname: Olalla-Saad
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Fernando Ferreira
authors.initials: FF
authors.lastname: Costa
authors.affiliation: INCT do Sangue, Haematology and Haemotherapy Centre, School of Medicine, University of Campinas - UNICAMP, Campinas, São Paulo, Brazil.
authors.forename: Nicola
authors.initials: N
authors.lastname: Conran
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D001792:Blood Platelets / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion; D018920:Coculture Techniques; D019040:E-Selectin / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D053583:Interleukin-1beta / Q000096:biosynthesis / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D019007:P-Selectin / Q000235:genetics / Q000378:metabolism; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000235:genetics / Q000378:metabolism; D061251:Primary Cell Culture; D015398:Signal Transduction / Q000235:genetics*; D013450:Sulfones / Q000494:pharmacology
chemical_list: C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D019040:E-Selectin; C573420:ICAM1 protein, human; D053583:Interleukin-1beta; D016209:Interleukin-8; D016328:NF-kappa B; D009570:Nitriles; D019007:P-Selectin; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C546936:SELE protein, human; D013450:Sulfones; D018799:Intercellular Adhesion Molecule-1