Characterisation of lubricin in synovial fluid from horses with osteoarthritis
Autor: | Niclas G. Karlsson, Stina Ekman, Ulla Rüetschi, C. Jin, Anders Lindahl, Emilia Svala, Eva Skiöldebrand |
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Rok vydání: | 2015 |
Předmět: |
musculoskeletal diseases
0301 basic medicine Cartilage Articular Pathology medicine.medical_specialty Glycosylation Osteoarthritis 03 medical and health sciences chemistry.chemical_compound Western blot In vivo Synovial Fluid medicine Synovial fluid Animals Horses Glycoproteins chemistry.chemical_classification medicine.diagnostic_test Cartilage General Medicine medicine.disease In vitro 030104 developmental biology medicine.anatomical_structure chemistry Gene Expression Regulation Horse Diseases Glycoprotein Biomarkers |
Zdroj: | Europe PubMed Central |
ISSN: | 2042-3306 |
Popis: | SummaryReason for performing study The glycoprotein lubricin contributes to the boundary lubrication of the articular cartilage surface. The early events of osteoarthritis involve the superficial layer where lubricin is synthesised. Objectives To characterise the glycosylation profile of lubricin in synovial fluid from horses with osteoarthritis and study secretion and degradation of lubricin in an in vitro inflammation cartilage model. Study design In vitro study. Methods Synovial fluid samples collected from horses with joints with normal articular cartilage and structural osteoarthritic lesions; with and without osteochondral fragments, were analysed for the lubricin glycosylation profiles. Articular cartilage explants were stimulated with or without interleukin-1β for 25 days. Media samples collected at 3-day intervals were analysed by quantitative proteomics, western blot and enzyme-linked immunosorbent assay. Results O-glycosylation profiles in synovial fluid revealed both Core 1 and 2 O-glycans, with Core 1 O-glycans predominating. Synovial fluid from normal joints (49.5 ± 1.9%) contained significantly lower amounts of monosialylated Core 1 O-glycans compared with joints with osteoarthritis (53.8 ± 7.8%, P = 0.03) or joints with osteochondral fragments (57.3 ± 8.8%, P = 0.001). Additionally, synovial fluid from normal joints (26.7 ± 6.7%) showed higher amounts of disialylated Core 1 O-glycan than from joints with osteochondral fragments (21.2 ± 4.9%, P = 0.03). A C-terminal proteolytic cleavage site in lubricin was found in synovial fluid from normal and osteochondral fragment joints and in media from interleukin-1β stimulated and unstimulated articular cartilage explants. Conclusions This is the first demonstration of a change in the glycosylation profile of lubricin in synovial fluid from diseased equine joints compared with that from normal joints. We demonstrate an identical proteolytic cleavage site of lubricin both in vitro and in vivo. The reduced sialation of lubricin in synovial fluid from diseased joints may affect the boundary lubricating ability of the superficial layer of articular cartilage and could be one of the early events in the progression of osteoarthritis. |
Databáze: | OpenAIRE |
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