Short-term effects of amelogenin gene splice products A+4 and A-4 implanted in the exposed rat molar pulp.
In order to study the short-time effects of two bioactive low-molecular amelogenins A+4 and A-4, half-moon cavities were prepared in the mesial aspect of the first maxillary molars, and after pulp exposure, agarose beads alone (controls) or beads soaked in A+4 or A-4 (experimental) were implanted into the pulp. After 1, 3 or 7 days, the rats were killed and the teeth studied by immunohistochemistry. Cell proliferation was studied by PCNA labeling, positive at 3 days, but decreasing at day 7 for A+4, whilst constantly high between 3 and 7 days for A-4. The differentiation toward the osteo/odontoblast lineage shown by RP59 labeling was more apparent for A-4 compared with A+4. Osteopontin-positive cells were alike at days 3 and 7 for A-4. In contrast, for A+4, the weak labeling detected at day 3 became stronger at day 7. Dentin sialoprotein (DSP), an in vivo odontoblast marker, was not detectable until day 7 where a few cells became DSP positive after A-4 stimulation, but not for A+4. These results suggest that A +/- 4 promote the proliferation of some pulp cells. Some of them further differentiate into osteoblast-like progenitors, the effects being more precocious for A-4 (day 3) compared with A+4 (day 7). The present data suggest that A +/- 4 promote early recruitment of osteogenic progenitors, and evidence functional differences between A+4 and A-4.
D020341:Absorbable Implants; D053523:Amelogenin / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D003782:Dental Pulp / Q000378:metabolism*; D003785:Dental Pulp Capping / Q000379:methods*; D003786:Dental Pulp Cavity / Q000187:drug effects; D003789:Dental Pulp Exposure / Q000628:therapy; D005899:Glass Ionomer Cements / Q000494:pharmacology; D007124:Immunoenzyme Techniques; D008963:Molar; D019154:Protein Splicing / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012685:Sepharose / Q000494:pharmacology
D053523:Amelogenin; D015415:Biomarkers; D005899:Glass Ionomer Cements; D012685:Sepharose