Induction of matrix metalloproteinase-8 in human fibroblasts by basic calcium phosphate and calcium pyrophosphate dihydrate crystals: Effect of phosphocitrate
Pm. Reuben et al., Induction of matrix metalloproteinase-8 in human fibroblasts by basic calcium phosphate and calcium pyrophosphate dihydrate crystals: Effect of phosphocitrate, CONNECT TIS, 42(1), 2001, pp. 1
Although matrix metalloproteinase-8 (MMP-8) was regarded as the exclusive p
roduct of the neutrophils, recent studies have shown that it is also expres
sed in articular chondrocytes, rheumatoid synovial fibroblasts and endothel
ial cells. Our aim was to determine the expression of MMP-8 in human fibrob
lasts (HF) by reverse transcription/polymerase chain reaction (RT/PCR), Nor
thern and Western blotting methods and MMP-8 activity assay. We have shown
the expression of MMP-8 in HF and its dose-dependent upregulation by basic
calcium phosphate (BCP) and calcium pyrophosphate dihydrate (CPPD) crystals
which are markers of severe joint degeneration in osteoarthritis. These ef
fects require new protein synthesis and are reversed by phosphocitrate (PC)
. The results also show that this fibroblast MMP-8 is distinct from the neu
trophil MMP-8 and from the fibroblast MMP-1. These results indicate that MM
P-8 may play a significant role in the pathogenic effects of the crystals i
n osteoarthritis.