title: Sphingolipids in human synovial fluid--a lipidomic study.
abstract: Articular synovial fluid (SF) is a complex mixture of components that regulate nutrition, communication, shock absorption, and lubrication. Alterations in its composition can be pathogenic. This lipidomic investigation aims to quantify the composition of sphingolipids (sphingomyelins, ceramides, and hexosyl- and dihexosylceramides) and minor glycerophospholipid species, including (lyso)phosphatidic acid, (lyso)phosphatidylglycerol, and bis(monoacylglycero)phosphate species, in the SF of knee joints from unaffected controls and from patients with early (eOA) and late (lOA) stages of osteoarthritis (OA), and rheumatoid arthritis (RA). SF without cells and cellular debris from 9 postmortem donors (control), 18 RA, 17 eOA, and 13 lOA patients were extracted to measure lipid species using electrospray ionization tandem mass spectrometry--directly or coupled with hydrophilic interaction liquid chromatography. We provide a novel, detailed overview of sphingolipid and minor glycerophospholipid species in human SF. A total of 41, 48, and 50 lipid species were significantly increased in eOA, lOA, and RA SF, respectively when compared with normal SF. The level of 21 lipid species differed in eOA SF versus SF from lOA, an observation that can be used to develop biomarkers. Sphingolipids can alter synovial inflammation and the repair responses of damaged joints. Thus, our lipidomic study provides the foundation for studying the biosynthesis and function of lipid species in health and most prevalent joint diseases.
authors.affiliation: Department of Orthopedics, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Marta Krystyna
authors.initials: MK
authors.lastname: Kosinska
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Liebisch
authors.affiliation: Department of Biochemistry, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Guenter
authors.initials: G
authors.lastname: Lochnit
authors.affiliation: Medical Clinic II/IV, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Wilhelm
authors.affiliation: Department of Orthopedics, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Klein
authors.affiliation: Internistisches Praxiszentrum am Krankenhaus Balserische Stiftung, Giessen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kaesser
authors.affiliation: Institute of Forensic Medicine, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Lasczkowski
authors.affiliation: Department of Orthopedics, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Rickert
authors.affiliation: Department of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Regensburg, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Schmitz
authors.affiliation: Department of Orthopedics, Justus-Liebig-University Giessen, Giessen, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Steinmeyer
mesh_terms: D000328:Adult; D000368:Aged; D002308:Cardiolipins / Q000378:metabolism; D016022:Case-Control Studies; D002518:Ceramides / Q000378:metabolism; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D055432:Metabolomics; D008875:Middle Aged; D011180:Postmortem Changes; D013107:Sphingolipids / Q000032:analysis* / Q000378:metabolism*; D013109:Sphingomyelins / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D014019:Tissue Donors; D055815:Young Adult
chemical_list: D002308:Cardiolipins; D002518:Ceramides; D013107:Sphingolipids; D013109:Sphingomyelins