title: Expression of heat shock protein receptors on fibroblast-like synovial cells derived from rheumatoid arthritis-affected joints.
abstract: We examined the membrane expression of inducible Hsp70 and HSP receptors like TLR2, TLR4, CD14, CD36, CD40 and CD91 on fibroblast-like synovial cells (SC) derived from synovial tissue in 23 patients with rheumatoid arthritis (RA), who underwent synovectomy by using flow cytometric analysis. For comparison, autologous skin fibroblasts (SF) derived from the operation wound were tested. Significantly higher Hsp70 expression was found on synovial cells than on skin fibroblasts (median SC 21.4% x SF 5.0%, P < 0.001). Both synovial cells and skin fibroblasts expressed high levels of cell surface CD91 (median SC 80.2% x SF 79.2%), however, no or low levels of CD14, CD40, TLR2, TLR4 and CD36. Further, we observed high co-expression of CD91 and Hsp70 on RA synovial cells (median 18.6%), while skin fibroblasts showed only background Hsp70 expression (median 3.9%, P < 0.001). Since we demonstrated the high prevalence of inducible Hsp70 in RA synovial fluids, we speculate that Hsp70 might be captured onto the membrane of synovial cells from the extracellular space via the CD91 receptor. The significance of the Hsp70 interaction with synovial cells via CD91 remains undefined, but may mediate other non-immune purposes.
authors.affiliation: Department of Molecular Biology and Cell Pathology, 3rd Medical Faculty, Charles University, Ruska 87, Prague 10, 10000, Czech Republic. ilona.hromadnikova@lf3.cuni.cz
authors.forename: Ilona
authors.initials: I
authors.lastname: Hromadnikova
authors.forename: Thi Thu Hien
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Denisa
authors.initials: D
authors.lastname: Zlacka
authors.forename: Lucie
authors.initials: L
authors.lastname: Sedlackova
authors.forename: Stanislav
authors.initials: S
authors.lastname: Popelka
authors.forename: David
authors.initials: D
authors.lastname: Veigl
authors.forename: Jan
authors.initials: J
authors.lastname: Pech
authors.forename: Pavla
authors.initials: P
authors.lastname: Vavrincova
authors.forename: Antonin
authors.initials: A
authors.lastname: Sosna
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D015331:Cohort Studies; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D008297:Male; D008875:Middle Aged; D013582:Synovial Fluid; D013583:Synovial Membrane / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D018840:HSP70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; C475476:LRP1 protein, human; D026503:Low Density Lipoprotein Receptor-Related Protein-1