SYNOPSIS
Bone cells are regulated by interaction with growth factors and components of the extracellular matrix. Syndecans are transmembrane heparan sulfate proteoglycans known to bind both other extracellular matrix molecules and certain growth factors. In this study using quantitative real-time RT-PCR, we investigated the expression of the syndecan family in normal human osteoblasts exposed to interleukin (IL)-1β as a bone resorptive agent. RT-PCR analysis demonstrated the mRNA expression of syndecan-1, -2 and -4 in normal human osteoblasts. When cells were incu-bated with IL-1β, there were significant decreases in mRNA levels for syndecan-1 and -2 at 24 h compared with time-matched controls. In contrast, the expression of syndecan-4 in IL-1β-stimulated osteoblasts markedly increased at 6 h followed by a decrease at 24 h. These results demonstrate that syndecan-1, -2 and -4 are synthesized in human osteoblasts, and syndecan-4 gene transcription is rapidly responsive to an inflammatory mediator.

Key words:syndecan, osteoblast, IL-1β