Distribution of tenascin-X in different synovial samples and synovial membrane-like interface tissue from aseptic loosening of total hip replacement

Abstract

 The distribution of tenascin-X (Tn-X) was investigated in synovial samples from rheumatoid arthritis (RA), osteoarthritis (OA) and knee injuries, and in synovial membrane-like interface tissue (SMLIT) from aseptic loosening of total hip replacement (THR). An affinity purified rabbit antiserum against Tn-X was applied in avidin-biotin-peroxidase complex method. Double immunofluorescence labeling was used to assess the spatial relationship of Tn-X and Tn-C. All samples showed Tn-X immunoreactivity. Strong staining appeared in the lining and lining-like layers of RA and SMLIT samples, respectively. An intensive immunoreactivity was also found in pannus tissue in RA, and around multinucleate giant cells and polyethylene wear debris in SMLIT. Staining intensity/extent varied significantly in different samples in the following rank order: SMLIT, RA, OA, knee synovium membrane. Double labeling revealed two patterns of Tn-X/Tn-C distribution, reciprocal and co-localization. Our results suggest that Tn-X is an essential component of normal synovial membrane, and that inflammatory mediators may increase local Tn-X production. Tn-X distribution is not always reciprocal to that of Tn-C.