Transforming growth factor-β isoform expression in mature human healthy and carious molar teeth

Transforming growth factor (TGF)-beta isoforms have been implicated in cellular signalling during tooth development and repair, but little is known of their cellular localisation or distribution within the dental tissues in the mature tooth. This study investigated the presence of TGF-beta 1, beta 2 and beta 3 isoforms in tissues of sound and carious human molar teeth, to understand better the expression of TGF-beta s during health and disease. In healthy tissues, odontoblasts, cells of the cell rich layer, pulpal fibroblasts and endothelial cells were stained to varying degrees for all isoforms, with TGF-beta 3 showing the greatest intensity and TGF-beta 1 the weakest intensity. Similar patterns of staining were observed in carious teeth; however, TGF-beta 1 showed significantly increased staining intensity within odontoblasts and pulpal cells of carious teeth (p < 0.001). Biochemical analysis showed greater amounts of TGF-beta 1 in tertiary dentine than in primary dentine samples. The expression of TGF-beta s in odontoblasts and the increased presence of TGF-beta 1 in tertiary dentine suggest that these isoforms may be important in odontoblast behaviour and the modulation of the tissue response to injury.