Expression of vitronectin and its integrin receptors in the synovial membrane-like interface tissue from aseptic loosening of total hip replacement.

Abstract

To investigate expression of vitronectin (VN) and its integrin (Int) receptors in synovial membrane-like interface tissue (SMLIT) in aseptic loosening of total hip replacement (THR), and the potential role of VN-Int interaction in production of collagenase-3. Avidin-biotin-peroxidase complex (ABC) staining was used to detect distribution of VN and Int alphaV, beta3, and beta5 subunits. Immunofluorescence labeling with FITC and TRITC conjugated IgG was used to localize Int beta3 subunit and matrix metalloproteinase (MMP-13) double positive cells in SMLIT. Intensive VN immunoreactivity was found in the lining-like layers, sublining area, and endothelium of SMLIT. Statistical analysis of the VN staining score revealed a significant difference between SMLIT and control synovial membrane. All 3 Int subunits appeared in the lining-like layers and sublining area. The Int beta3 subunit was also detected in giant cells of SMLIT. Int beta5 subunit staining was relatively weak and rarely found in vascular endothelium. Immunofluorescence labeling showed many double positive cells in the lining-like layer and sublining area of SMLIT. Expressions of VN and Int alphaVbeta3 and alphaVbeta5 are increased in SMLIT compared with that in OA synovial membrane. Int alphaVbeta3 engagement with VN might play a potential role in local MMP-13 production in SMLIT.