title: Increased expression of EMMPRIN in the tissue around loosened hip prostheses.
abstract: Matrix metalloproteinases (MMPs) have been shown to play a role in aseptic loosening of total hip replacement (THR). Extracellular matrix metalloproteinase inducer (EMMPRIN) can upregulate expression of several MMPs but has little effect on their tissue inhibitor (TIMP). Using the avidin-biotin-peroxidase complex immunostaining method, we detected strong immunoreactivity of EMMPRIN in the lining-like layers, sublining area and vascular endothelium of synovial membrane-like interface tissue around loosened prostheses. In contrast, EMMPRIN staining was very weak in the synovial samples from patients with hip arthrosis. Double immunofluorescence labeling revealed EMMPRIN/MMP-1 double-positive cells in lining-like layers and the sublining area of interface tissue. Our findings indicate that EMMPRIN expression is upregulated in interface tissue, and that locally accumulated EMMPRIN may modulate MMP-1 expression. An imbalance in the activity of MMPs and TIMP may lead to tissue destruction and periprosthetic osteolysis. These biological responses, combined with mechanical stress caused by micromotion and oscillating fluid pressure, may eventually cause aseptic loosening of THR.
authors.affiliation: Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Finland. tianfangl@yahoo.com
authors.forename: T F
authors.initials: TF
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Santavirta
authors.forename: I
authors.initials: I
authors.lastname: Virtanen
authors.forename: M
authors.initials: M
authors.lastname: Könönen
authors.forename: M
authors.initials: M
authors.lastname: Takagi
authors.forename: Y T
authors.initials: YT
authors.lastname: Konttinen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D051926:Basigin; D016022:Case-Control Studies; D019544:Equipment Failure Analysis; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000032:analysis / Q000276:immunology; D008562:Membrane Glycoproteins / Q000032:analysis* / Q000276:immunology; D008875:Middle Aged; D011475:Prosthesis Failure; D012307:Risk Factors; D013314:Stress, Mechanical; D013583:Synovial Membrane / Q000737:chemistry*
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; C497886:BSG protein, human; D008562:Membrane Glycoproteins; D051926:Basigin; D020781:Matrix Metalloproteinase 1