Distribution of transforming growth factor-β1-binding proteins and low-affinity receptors during odontoblast differentiation in the mouse

Transforming growth factor-β1 (TGF-β1) was immunolocalized within differentiated odontoblasts and ameloblasts while LAP-β1 was detected at the apicol pole of odonotoblasts and ameloblasts and in predentine. Anti-LAP-β1 antibodies also stained the epithelial-mesenchymal junction (EMJ). Decorin was immunolocalized in young functional odonotoblasts and in both predentine and dentine. Biglycan was similarly distributed but absent from dentine. Immunostaining with anti-latent TGF-β1 binding protein-1 (LTBP-1) showed fibrillar structures located at the EMJ and between predontoblasts and odontoblasts; at older states staining was restricted to the dental papilla and sac. Thus differentiated odonotoblasts express TGF-β1 and in a more restricted manner decorin, biglycan and LAP-β1; it can be assumed that LGF-β1 is able to interact with the three molecules present in predentine. Earlier, LTBP-1 and LAP-β1, both present at the EMJ, may contribute to odontoblast differentiation.