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Gelatinolytic and Collagenolytic Activity in Periprosthetic Tissues from Loose Hip Endoprostheses SPYROS A. SYGGELOS, SOFIA C. ELEFTHERIOU, ELEFTHERIA GIANNOPOULOU, ELIAS PANAGIOTOPOULOS, and ALEXIOS J. ALETRAS
ABSTRACT. Objective. To study the contribution of different members of the metalloproteinases (MMP) family in gelatinolytic and collagenolytic potential, namely dinitrophenyl-Pro-Gln-Gly-Ile-Ala-Gly-Gln-D-Arg (DNP-S) sensitive proteolytic activity, in loose total hip arthroplasty (THA) endoprostheses. Methods. Periprosthetic tissues and fluid samples were collected from patients subjected to hip endoprosthesis replacement. DNP-S sensitive proteolytic activity was evaluated by the degradation of synthetic DNP-S and reverse phase high performance liquid chromatography, while gelatinolytic activity was assessed by gelatin zymography. The isolation and separation of gelatinases was performed by gelatin- and concanavalin A-Sepharose affinity chromatographies and the identification of collagenases by immunoblot analysis. Results. High gelatinolytic activity was observed in all periprosthetic tissue extracts and fluid samples. All samples also exhibited DNP-S degrading activity, without pretreatment by activating agents. Upon fractionation of MMP by gelatin-Sepharose affinity chromatography it was found that the gelatin-unbound collagenases are exclusively responsible for DNP-S degrading activity. Activated species of both MMP-1 and 13 were detected in most samples, but not the soluble form of MT1-MMP. Separation of gelatinases from each other and treatment with 4-aminophenylmercuric acetate (APMA) revealed that both enzymes mainly existed in complex with tissue inhibitor of metalloproteinase (TIMP). Conclusion. MMP-1 and MMP-13, which exist in activated form, could be responsible for the DNP-S-degrading activity in periprosthetic tissues and fluids, while the gelatinases do not contribute in this potential, since they mainly exist in complex with TIMP. The 2 collagenases may play a key role in the loosening of THA endoprostheses. (J Rheumatol 2001;28:1319-29) Key Indexing Terms:
METALLOPROTEINASES |