Altered expression of matrix metalloproteinases within mineralizing bone cells in vitro in the presence of fluoride.
Fluoride is known to alter mineralization within bone, although the mechanism for its action is unclear. An important stage in the formation of mineralized tissues is the remodeling of the osteoid, facilitating mineral deposition. Using a bone mineralizing culture system derived from rat femur washes, this study investigated the influence of fluoride on MMP expression at a developmental stage relating to the onset of mineralization. Bone cells cultured in the absence of fluoride synthesized an active form of a 45-kD MMP, which was immunoreactive with an antibody to human MMP-1 (although full characterization of this MMP was not achieved), trace levels of an MMP immunoreactive with anti-MMP-3, and a 66-kD proteolytic species. Incubation in 10(-7) and 10(-5) M fluoride resulted in a decrease in expression of the 45-kD MMP, sharp increases in the expression of MMP-3, and the appearance of a band at 110 kD, which showed immunoreactivity for MMP-9. The influence of fluoride on MMP expression is likely to influence the composition of the remodeling matrix and subsequent mineralization and offers a potential mechanism by which fluoride alters mineralization.
Department of Basic Dental Science, Dental School, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom. waddingtonrj@cardiff.ac.uk
R J
RJ
Waddington
M S
MS
Langley
D000818:Animals; D002113:Calcification, Physiologic / Q000187:drug effects; D002478:Cells, Cultured; D005269:Femur / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D005459:Fluorides / Q000494:pharmacology*; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D020782:Matrix Metalloproteinases; D005459:Fluorides