Cell surface proteoglycan expression by human periodontal cells

Cell surface proteoglycans are known to be involved in many functions inclu ding interactions with components of the extracellular microenivironment an d serve to influence cell shape, adhesion, proliferation, and differentiati on. They also can act as co-receptors, to help bind and modify the action o f various growth factors and cytokines. Despite their strategic location an d relevance to cell function, fee studies have considered the nature of the cell surface proteoglycans associated with cells of the periodontium. Due to the structural complexity and multiplicity of cell types in the periodon tium, we have selected three different cell lines (gingival connective tiss ue fibroblast, periodontal ligament fibroblast, and osteoblast) which each represent the unique functions within the periodontium to study the express ion of cell surface proteoglycans. We hypothesized that a number of cell su rface proteoglycans mill be expressed by human periodontal cells and these may be related to the source and function of the cell. Western blotting and RT-PCR methods mere used to study the expression of five cell surface prot eoglycans (syndecan-1, -2, -4, glypican and betaglycan) in three cell lines of human periodontal cells in vitro. Our results demonstrated the expressi on of protein cores for syndecan-1 (43 kDa), syndecan-2 (48 kDa), syndecan- 4 (35 kDa), glypican (64 kDa), and betaglycan (100-110 kDa). RT-PCR results confirmed that all of these cells produced mRNA for the cell surface prote oglycans under study, of which syndecan-2 showed a significant difference i n expression between the periodontal ligament fibroblasts, gingival fibrobl asts and osteoblasts. We conclude that the presence of specific cell surfac e proteoglycans on periodontal cells implies a likely role for these molecu les in cell-cell, cell-matrix interactions involved in periodontal disease and/or regeneration of the periodontium, of which they may have distinctive functions related to the source and function of these cells.