title: Proteomic analysis of tendon extracellular matrix reveals disease stage-specific fragmentation and differential cleavage of COMP (cartilage oligomeric matrix protein).
abstract: During inflammatory processes the extracellular matrix (ECM) is extensively remodeled, and many of the constituent components are released as proteolytically cleaved fragments. These degradative processes are better documented for inflammatory joint diseases than tendinopathy even though the pathogenesis has many similarities. The aims of this study were to investigate the proteomic composition of injured tendons during early and late disease stages to identify disease-specific cleavage patterns of the ECM protein cartilage oligomeric matrix protein (COMP). In addition to characterizing fragments released in naturally occurring disease, we hypothesized that stimulation of tendon explants with proinflammatory mediators in vitro would induce fragments of COMP analogous to natural disease. Therefore, normal tendon explants were stimulated with IL-1β and prostaglandin E2, and their effects on the release of COMP and its cleavage patterns were characterized. Analyses of injured tendons identified an altered proteomic composition of the ECM at all stages post injury, showing protein fragments that were specific to disease stage. IL-1β enhanced the proteolytic cleavage and release of COMP from tendon explants, whereas PGE2 had no catabolic effect. Of the cleavage fragments identified in early stage tendon disease, two fragments were generated by an IL-1-mediated mechanism. These fragments provide a platform for the development of neo-epitope assays specific to injury stage for tendon disease.
authors.affiliation: From the Department of Clinical Sciences and Services, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, United Kingdom and.
authors.forename: Stephanie Georgina
authors.initials: SG
authors.lastname: Dakin
authors.forename: Roger Kenneth Whealands
authors.initials: RK
authors.lastname: Smith
authors.forename: Dick
authors.initials: D
authors.lastname: Heinegård
authors.forename: Patrik
authors.initials: P
authors.lastname: Önnerfjord
authors.forename: Areej
authors.initials: A
authors.lastname: Khabut
authors.forename: Jayesh
authors.initials: J
authors.lastname: Dudhia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D064236:Cartilage Oligomeric Matrix Protein / Q000737:chemistry / Q000378:metabolism*; D002853:Chromatography, Liquid; D003470:Culture Media; D015232:Dinoprostone / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism*; D006736:Horses; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D040901:Proteomics / Q000379:methods*; D052256:Tendinopathy / Q000378:metabolism* / Q000473:pathology*; D013710:Tendons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D014022:Tissue Survival / Q000187:drug effects
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D003470:Culture Media; D053583:Interleukin-1beta; D015232:Dinoprostone
keywords: Extracellular Matrix; Inflammation; Mass Spectrometry (MS); Peptides; Proteomics; Tendon