title: The effects of pressure on chondrocyte tumour necrosis factor receptor expression.
abstract: This work was performed to determine whether one aspect of load, pressure, could alter tumour necrosis factor (TNF) receptor type I (RI) expression on chondrocytes. Encapsulated tsT/AC62, osteoarthritic (OA) or non-arthritic (NA) chondrocytes were centrifuged at speeds representing 5 or 20 MPa, incubated for specific periods, released from alginate and TNFRI and II (TNFRII) expression determined by flow cytometry. Significant (p<0.05, n=4) changes in tsT/AC62 chondrocyte TNFRI expression were apparent 24 hours after application of 20 MPa. Five or 20 MPa increased OA chondrocyte TNFRI expression; chondrocytes from some OA patients were markedly sensitive to 20 MPa. NA chondrocyte TNFRI expression usually decreased in response to 5 and 20 MPa. Significant pressure-induced differences in TNFRI expression between NA and OA groups were apparent at 5, but not 20 MPa. Pressure did not significantly alter TNRFII expression on tsT/AC62, NA or OA chondrocytes. These results suggest a mechanism whereby sensitivity of chondrocytes to the effects of TNFalpha may be increased, in susceptible individuals, in regions of the joint that experience peak loading.
authors.affiliation: Department of Pathology, University of Bristol Medical School, Bristol BS8 1TD, UK. Carole.Westacott@bristol.ac.uk
authors.forename: C I
authors.initials: CI
authors.lastname: Westacott
authors.forename: J P G
authors.initials: JP
authors.lastname: Urban
authors.forename: M B
authors.initials: MB
authors.lastname: Goldring
authors.forename: C J
authors.initials: CJ
authors.lastname: Elson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism*; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D004198:Disease Susceptibility; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism* / Q000473:pathology; D011312:Pressure; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D047888:Receptors, Tumor Necrosis Factor, Type I
chemical_list: D015703:Antigens, CD; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I