Hyaluronan in Human Deciduous Tooth Germs in the Bell Stage

Abstract

The primary aim of the present study was a localization of hyaluronan (HA) in human deciduous tooth germs in the bell stage. HA was compared to the content of chondroitin sulfates (CSs). HA was detected with a biotin-labeled HA-binding protein (HABP) and CS with a monoclonal antibody. As controls, enzyme digestions were carried out. Furthermore, the glycosaminoglycans were investigated histochemically with enzyme digestions followed by alcian blue staining. The investigation showed a considerable content of HA in the stellate reticulum, although CS was also found, primarily when treatment with protease was omitted. The dental papilla contained both HA and CS, while the predentin and the dentin contained only CS. The enamel did not contain any CS, but some staining with HABP was observed along the borderline between the ameloblasts and the enamel. The significance of HA in the stellate reticulum is discussed. The importance of carrying out investigations with and without protease digestions is stressed.

Quantitative image analysis of hyaluronan expression in human tooth germs

“…At the early bud stage of development, the dental basement membrane contains abundant HA (14). However, the present data show that the HA positivity undergoes a substantial decrease at subsequent stages of development.…”

“…Previous studies on hyaluronan in developing tooth germs have suggested that the highly hydrated HA may support the dierentiation of the neural crest-derived mesenchymal cells, facilitate metabolite transport within dental papilla, and regulate hard tissue mineralization. The distribution of HA has been described in tooth germs by several authors (13,14).…”

“…This technique, however, cannot be regarded speci®c for hyaluronan, because testicular hyaluronidase also binds and cleaves chondroitin-4-and -6-sulphates. A more speci®c histochemical detection of HA has been made using HA-binding region of aggrecan, but no comprehensive data were collected from dierent developmental stages of the human specimens (14).…”

Surface Treatment of Flexor Tendon Autografts with Carbodiimide-Derivatized Hyaluronic Acid<sbt aid="1047845">An in Vivo Canine Model</sbt>

“…We based the decision not to include such a control group in part on previous clinical and animal studies of the use of unmodified hyaluronic acid with tendon surgery 26,34,35 as well as published reports in which there was no difference in gliding resistance, after repetitive motion in vitro, between tendons treated with unmodified hyaluronic acid and untreated tendons 41,55 . Finally, while the hyaluronic acid-binding-protein technique has been well studied and accepted as a sensitive and specific hyaluronic acid staining method [63][64][65][66][67][68] , it is only semiquantitative as a result of a variety of factors including, but not limited to, sample preparation (frozen or paraffin), dilution of the antibody, staining techniques (for example, washing duration and frequency), varying photographic conditions and lighting, and selection of the analytic area. Using the ratio between the cd-HA and saline-solution groups may have eliminated some errors in photographic and color density analysis as paired tendons (one treated with cd-HA and one treated with saline solution) from the same dog were photographed and analyzed together.…”

Immunohistochemical Expression of Integrins and CD44 in Ameloblastomas.

“…Changes in CD44 expression are associated with progression and metastasis in a variety of human tumors (20,21,23,25). Expression of hyaluronic acid and CD44 has been recognized in dental epithelial structures of tooth germs, suggesting that these molecules play a role in morphogenesis and differentiation during tooth development (26,31,45). In the present study, CD44 was expressed widely in tumor cells of ameloblastomas and one CCOT, but keratinizing areas in acanthomatous ameloblastomas showed decreased expression of CD44.…”