title: Sickle red cells as danger signals on proinflammatory gene expression, leukotriene B4 and interleukin-1 beta production in peripheral blood mononuclear cell.
abstract: This study tested the hypothesis that sickle red blood cell (SS-RBC) induce Toll-like receptors (TLR) and Nod-like receptor family, pyrin domain containing 3 (NLRP3)- inflammasome expression in peripheral blood mononuclear cells (PBMC). TLR and NLRP3 inflammasome could contribute to the maintenance of the inflammatory status in sickle cell anemia (SCA) patients, since SS-RBC act as danger signals activating these pathways. In this study, first, we evaluated TLR (2, 4, 5 and 9), NLRP3, Caspase-1, interleukin (IL)-1β and IL-18 expression in PBMC freshly isolated from SCA patients (SS-PBMC) in comparison with PBMC from healthy individuals (AA-PBMC). In the second moment, we investigated whether SS-RBC could interfere with the expression of these molecules in PBMC from healthy donor, in the absence or presence of hydroxyurea (HU) in vitro. TLRs and NLRP3 inflammasome expression were investigated by qPCR. IL-1β, Leukotriene-B4 (LTB4) and nitrite production were measured in PBMC (from healthy donor) culture supernatants. TLR2, TLR4, TLR5, NLRP3 and IL-1β were highly expressed in SS-PBMC when compared to AA-PBMC. Additionally, SS-RBC induced TLR9, NLRP3, Caspase-1, IL-1β and IL-18 expression and induced IL-1β, LTB4 and nitrite production in PBMC cultures. HU did not prevent TLR and NLRP3 inflammasome expression, but increased TLR2 and IL-18 expression and reduced nitrite production. In conclusion, our data suggest that TLR and inflammasome complexes may be key inducers of inflammation in SCA patients, probably through SS-RBC; also, HU does not prevent NLRP3 inflammasome- and TLR-dependent inflammation, indicating the need to develop new therapeutic strategies to SCA patients that act with different mechanisms of those observed for HU.
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil; Instituto de Ciências da Saúde (ICS), Universidade Federal da Bahia (UFBA), 40110902 Salvador, Bahia, Brazil.
authors.forename: Thassila N
authors.initials: TN
authors.lastname: Pitanga
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Ricardo R
authors.initials: RR
authors.lastname: Oliveira
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Dalila L
authors.initials: DL
authors.lastname: Zanette
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Guarda
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Rayra P
authors.initials: RP
authors.lastname: Santiago
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Sanzio S
authors.initials: SS
authors.lastname: Santana
authors.affiliation: Fundação de Hematologia e Hemoterapia da Bahia (HEMOBA), 40286240 Salvador, Bahia, Brazil.
authors.forename: Valma M L
authors.initials: VML
authors.lastname: Nascimento
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Jonilson B
authors.initials: JB
authors.lastname: Lima
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Graziele Q
authors.initials: GQ
authors.lastname: Carvalho
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Vitor V
authors.initials: VV
authors.lastname: Maffili
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil; Hospital Universitário Professor Edgard Santos (HUPES), UFBA, 40110060 Salvador, Bahia, Brazil.
authors.forename: Magda O S
authors.initials: MOS
authors.lastname: Carvalho
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Luiz C J
authors.initials: LCJ
authors.lastname: Alcântara
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil.
authors.forename: Valéria M
authors.initials: VM
authors.lastname: Borges
authors.affiliation: Fundação Oswaldo Cruz, Centro de Pesquisas Gonçalo Moniz - FIOCRUZ/BA, 40296710 Salvador, Bahia, Brazil; Faculdade de Farmácia, UFBA, 40170115 Salvador, Bahia, Brazil. Electronic address: mari@bahia.fiocruz.br.
authors.forename: Marilda S
authors.initials: MS
authors.lastname: Goncalves
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004913:Erythrocytes, Abnormal / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D020382:Interleukin-18 / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000378:metabolism* / Q000473:pathology; D007975:Leukotriene B4 / Q000096:biosynthesis*; D008297:Male; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein / Q000096:biosynthesis; D009573:Nitrites / Q000378:metabolism; D051193:Toll-Like Receptors / Q000096:biosynthesis
chemical_list: C508585:IL1B protein, human; D020382:Interleukin-18; D053583:Interleukin-1beta; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C453881:NLRP3 protein, human; D009573:Nitrites; D051193:Toll-Like Receptors; D007975:Leukotriene B4
keywords: IL-1β; Leukotriene B4; NLRP3 inflammasome; Sickle cell anemia; Sickle red cell; Toll-like receptors