A Scanu1, F Oliviero1, L Gruaz2, P Galozzi1, R Luisetto3, R Ramonda1, D Burger2, L Punzi1. 1. a Rheumatology Unit, Department of Medicine , University of Padova , Italy. 2. b Division of Immunology and Allergy, Inflammation and Allergy Research Group, Hans Wilsdorf Laboratory, University Hospital and Faculty of Medicine , University of Geneva , Switzerland. 3. c Department of Surgery, Oncology and Gastroenterology , University of Padova , Italy.
Abstract
OBJECTIVES: Monosodium urate (MSU) crystal deposition in gouty joints promotes the release of inflammatory mediators, in particular interleukin (IL)-1β. The induction of IL-1β production by MSU crystals requires a co-stimulus. The objective of this study was to determine which part of the synovial fluid (SF) provides co-stimulation to MSU crystals to induce IL-1β in macrophages. METHOD: The lipidic fraction (LF) and the protein fraction (PF) were isolated from the SF of patients with arthropathies. The PF was subfractionated according to different molecular weight (MW) ranges. THP-1 cells or human primary monocytes were stimulated with MSU crystals in the presence or absence of SF or SF fractions. IL-1β and IL-8 production and IL-1β mRNA expression were assessed by an enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR). RESULTS: Exposure of monocytes/macrophages to MSU crystals alone induced the moderate release of IL-8 but not of IL-1β. The production of IL-1β required the presence of both SF from patients with inflammatory arthritis (SFi) and MSU crystals. SF from patients with non-inflammatory arthritis, that is patients with osteoarthritis (OA), did not affect the IL-1β production but slightly enhanced the secretion of IL-8. Both MSU crystals and SFi were required for the induction of the IL-1β transcript, which was not expressed in the presence of either stimulus alone. SFi fractionation demonstrated that the MSU crystal co-stimulus was contained in the PF of SFi with MW > 50 kDa but not in the LF. CONCLUSIONS: This study shows that the SF of inflammatory arthritis patients, including gout patients, contains proteins required for the induction of IL-1β by MSU crystals in macrophages whereas lipids are not involved.
OBJECTIVES:Monosodium urate (MSU) crystal deposition in gouty joints promotes the release of inflammatory mediators, in particular interleukin (IL)-1β. The induction of IL-1β production by MSU crystals requires a co-stimulus. The objective of this study was to determine which part of the synovial fluid (SF) provides co-stimulation to MSU crystals to induce IL-1β in macrophages. METHOD: The lipidic fraction (LF) and the protein fraction (PF) were isolated from the SF of patients with arthropathies. The PF was subfractionated according to different molecular weight (MW) ranges. THP-1 cells or human primary monocytes were stimulated with MSU crystals in the presence or absence of SF or SF fractions. IL-1β and IL-8 production and IL-1β mRNA expression were assessed by an enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qPCR). RESULTS: Exposure of monocytes/macrophages to MSU crystals alone induced the moderate release of IL-8 but not of IL-1β. The production of IL-1β required the presence of both SF from patients with inflammatory arthritis (SFi) and MSU crystals. SF from patients with non-inflammatory arthritis, that is patients with osteoarthritis (OA), did not affect the IL-1β production but slightly enhanced the secretion of IL-8. Both MSU crystals and SFi were required for the induction of the IL-1β transcript, which was not expressed in the presence of either stimulus alone. SFi fractionation demonstrated that the MSU crystal co-stimulus was contained in the PF of SFi with MW > 50 kDa but not in the LF. CONCLUSIONS: This study shows that the SF of inflammatory arthritispatients, including goutpatients, contains proteins required for the induction of IL-1β by MSU crystals in macrophages whereas lipids are not involved.
Authors: Anna Scanu; Mariagrazia Lorenzin; Roberto Luisetto; Paola Galozzi; Augusta Ortolan; Francesca Oliviero; Andrea Doria; Roberta Ramonda Journal: Exp Biol Med (Maywood) Date: 2022-04-26
Authors: Francesca Oliviero; Sara Bindoli; Anna Scanu; Eugen Feist; Andrea Doria; Paola Galozzi; Paolo Sfriso Journal: Front Med (Lausanne) Date: 2020-04-30
Authors: Francesca Oliviero; Yessica Zamudio-Cuevas; Elisa Belluzzi; Lisa Andretto; Anna Scanu; Marta Favero; Roberta Ramonda; Giampietro Ravagnan; Alberto López-Reyes; Paolo Spinella; Leonardo Punzi Journal: Foods Date: 2019-11-07