Quantitative analysis of mRNA expression of TIMPs in the periprosthetic interface tissue of loose hips by real-time PCR system

Matrix metalloproteinases (MMPs) and their endogenous inhibitors, tissue in hibitors of metalloproteinases (TIMPs), have been reported to play a critic al role in extracellular degradation around artificial hip joints. Although messenger ribonucleic acid (mRNA) expression patterns of several MMPs and TIMPs were reported, there is no report of quantitative mRNA analysis of TI MPs in periprosthetic tissues. In this study, mRNA expression of four diffe rent types of TIMPs in periprosthetic interface tissue of loose hips was an alyzed by a quantitative polymerase chain reaction system. The mRNA express ion level of TIMP-1, -2, and -3 in periprosthetic interface tissue was sign ificantly higher than that in control. In contrast, the mRNA expression lev el of TIMP-4 in the periprosthetic interface tissue was lower. This study s uggested that increased levels of TIMP-1, -2, and -3, and decreased levels of TIMP-4 may contribute to pathologic extracellular matrix degradation in combination with MMPs, thus leading to prosthetic loosening and osteolysis around artificial total hip joints. (C) 2001 John Wiley & Sons, Inc.