透明质酸在小鼠下颌第一磨牙牙胚不同发育时期的表达

目的:检测透明质酸在小鼠下颌第一磨牙牙胚不同发育时期的表达,探讨其在小鼠牙胚发育过程中的作用。方法:取不同胎龄的ICR胎鼠,制备小鼠下颌第一磨牙不同发育时期切片,用免疫组织化学实验方法检测透明质酸在下颌第一磨牙牙胚组织中的表达情况。结果:透明质酸在小鼠下颌第一磨牙牙胚的不同发育阶段表达各异。在小鼠磨牙开始发生时,透明质酸即在增厚的牙板上皮中表达,随后在蕾状期牙蕾中央的上皮细胞间可见透明质酸的表达,而在深层的牙源性间充质表达则不明显。自帽状期至钟状晚期,透明质酸在牙胚星网状层细胞间以及牙源性间充质细胞的表达逐渐增强,而在基底膜、内外釉上皮细胞、成釉细胞以及成牙本质细胞所在区域不表达。结论:透明质酸在牙胚发育过程中呈现时间-空间特异性表达。特别是其在星网状层细胞以及牙乳头间充质细胞中的表达随着牙胚的发育逐渐增强提示其可能与牙胚的形态发生密切相关。

Temporal-spatial Expression of Hyaluronic Acid in the First Mandibular Mouse Molar Tooth Germs

Objective: To investigate the expression patterns of hyaluronic acid (HA) in the first mandibular molar tooth germs, and to explore its role during the tooth development of mouse. Methods: Serial paraffin sections of the first mandibular embryonic molars at different stages were made. The expression patterns of HA were analyzed by immunohistochemistry. Results: The expression patterns of HA in the first lower molars varied among the different stages. It slightly expressed in the dental epithelium at tooth initiation stage. And it could be detected in the central areas of the tooth bud during the bud stage, while in the underlying dental mesenchyme the immunostaining was slight. From the cap stage to the late bell stage, the expression of HA at the stellate reticulum cells and dental papillae increased gradually. However, it never expressed in basement membrane, outer and inner enamel epithelium, and the areas where the ameloblast or the odontoblast located. Conclusion: The expression of HA was in a temporal-spatial specific pattern. Particularly, its expression in the stellate reticulum and dental papillae increased gradually with the development of tooth germ. This result implies that HA may be involved in tooth morphogenesis of the mouse molars.