Kronmiller J E, Upholt W B, Kollar E J
Department of Biostructure and Function, School of Dental Medicine, University of Connecticut Health Center, Farmington 06032.
Arch Oral Biol. 1992 Feb;37(2):129-38. doi: 10.1016/0003-9969(92)90008-v.
Retinoids alter the patterning of murine odontogenesis in vivo and stimulate epithelial proliferation. Because odontogenesis is dependent on proliferation of mandibular epithelium, the effects of retinol on the patterning of odontogenic epithelium were studied. These experiments control for developmental stage, applied retinoid concentration and duration of exposure. Explants exposed for 24 h to 0.1 micrograms/ml of retinol exhibited enhanced odontogenesis. Day-9 mandibles exposed to retinol at 1-5 micrograms/ml had altered epithelial patterns consistent with those in previous in vivo experiments, including supernumerary epithelial buds in regions associated with supernumerary incisors in vivo. These changes were associated with a dose-dependent increase in epithelial proliferation and a prolonged expression of epidermal growth factor (EGF) mRNA. Altered expression of EGF mRNA may be responsible for the disrupted pattern of the dental lamina. This is the first report of a retinoid-induced alteration in EGF mRNA expression.
维甲酸可改变小鼠体内牙胚发生的模式并刺激上皮细胞增殖。由于牙胚发生依赖于下颌上皮细胞的增殖，因此研究了视黄醇对牙源性上皮细胞模式的影响。这些实验对发育阶段、应用的维甲酸浓度和暴露持续时间进行了控制。暴露于0.1微克/毫升视黄醇24小时的外植体显示出牙胚发生增强。暴露于1-5微克/毫升视黄醇的第9天下颌骨的上皮细胞模式发生了改变，与之前的体内实验一致，包括在体内与额外切牙相关区域出现额外的上皮芽。这些变化与上皮细胞增殖的剂量依赖性增加以及表皮生长因子（EGF）mRNA的延长表达有关。EGF mRNA表达的改变可能是牙板模式紊乱的原因。这是关于维甲酸诱导EGF mRNA表达改变的首次报道。
