Somerman M J, Shroff B, Agraves W S, Morrison G, Craig A M, Denhardt D T, Foster R A, Sauk J J
University of Maryland Dental School, Baltimore 21201.
J Biol Buccale. 1990 Sep;18(3):207-14.
There is general agreement that during development the extracellular environment plays a critical role in controlling cell differentiation. Data generated from numerous studies support the possibility that cell attachment proteins and their corresponding cell receptors are possible candidates for this role. In particular, our studies are directed at identifying attachment proteins in mature cementum and establishing the function of these proteins during root formation. Fractionation of guanidine HCL/EDTA extracts of cementum revealed the presence of a bone-associated attachment, BSP, as well as fractions containing as of yet undetermined attachment proteins. Immunofluorescent examination of 1st molar tissues during root formation, obtained from 7 day-old mice neonates, for bone-associated attachment proteins indicated that osteopontin is expressed in the area of Hertwig's epithelial root sheath, but not in the region of the dental papillae. However, dental papillae cells, considered to have the capacity to form cementum, attached to osteopontin coated dishes, in vitro. Thus, unique attachment proteins, as well as those previously identified, were found in mature cementum and during root development. Future studies focused on identifying attachment proteins of mature cementum and determining the spatial and temporal localization of these proteins, pre- and post-cementogenesis, will provide important information necessary for establishing the function of these proteins during root development.
人们普遍认为，在发育过程中，细胞外环境在控制细胞分化方面起着关键作用。众多研究产生的数据支持了细胞附着蛋白及其相应的细胞受体可能担任这一角色的可能性。特别是，我们的研究旨在鉴定成熟牙骨质中的附着蛋白，并确定这些蛋白在牙根形成过程中的功能。牙骨质的盐酸胍/乙二胺四乙酸提取物的分级分离显示存在一种与骨相关的附着蛋白骨桥蛋白，以及含有尚未确定的附着蛋白的组分。对7日龄新生小鼠第一磨牙牙根形成过程中的组织进行免疫荧光检查，以检测与骨相关的附着蛋白，结果表明骨桥蛋白在赫特维希上皮根鞘区域表达，但在牙乳头区域不表达。然而，被认为具有形成牙骨质能力的牙乳头细胞在体外可附着于包被有骨桥蛋白的培养皿。因此，在成熟牙骨质和牙根发育过程中发现了独特的附着蛋白以及先前已鉴定的蛋白。未来专注于鉴定成熟牙骨质的附着蛋白并确定这些蛋白在牙骨质形成前后的空间和时间定位的研究，将为确定这些蛋白在牙根发育过程中的功能提供必要的重要信息。
