Somerman M J, Shroff B, Foster R A, Butler W T, Sauk J J
Department of Periodontics/Prevention & Geriatrics, University of Michigan, School of Dentistry, Ann Arbor.
Proc Finn Dent Soc. 1992;88 Suppl 1:451-61.
There is a general agreement that the extracellular environment plays a critical role in controlling cell behavior. Thus, significant research efforts have focused on understanding the effects of extracellular matrix proteins on cell function. In particular we have focused on determining the role of adhesion proteins in the regulation of root formation. Using an OPN antibody, 2arN (generously provided by Drs Craig and Denhardt), the expression of OPN during root formation was determined. OPN (osteopontin) is a bone-associated adhesion protein. OPN was expressed in the dental follicle region of molars obtained from 3 day old CD-1 mice, but was not expressed in the odontoblast layer. In contrast by day 8, positive staining was noted in the odontoblast layer, as well as in the area of Hertwig's epithelial root sheath. However, at this same time point no positive labeling for 2arN was observed in the enamel organ or in the dental papillae cells. By day 15 positive staining for OPN was seen in the area of the periodontal ligament, as well as the region of primary deposition of extracellular matrix onto dentin. Also determined was the ability of fibronectin, OPN and dentin sialoprotein (DSP) to promote the attachment of dental ectomesenchymal cells, in vitro. Interestingly, these cells attached remarkable well on bacteriological dishes (control) in the absence of an adhesion protein. DSP did not increase cell attachment beyond that observed for control cells. In contrast, both fibronectin and OPN enhanced cell attachment. These studies, while preliminary indicate that OPN is expressed in a unique fashion during root development, thus suggesting a regulatory role for such adhesion proteins during root formation.
人们普遍认为细胞外环境在控制细胞行为方面起着关键作用。因此，大量研究工作集中在了解细胞外基质蛋白对细胞功能的影响。特别是，我们专注于确定黏附蛋白在根形成调控中的作用。使用一种OPN抗体（由Craig博士和Denhardt博士慷慨提供的2arN），确定了根形成过程中OPN的表达。OPN（骨桥蛋白）是一种与骨相关的黏附蛋白。OPN在从3日龄CD-1小鼠获得的磨牙的牙囊区域表达，但在成牙本质细胞层中不表达。相比之下，到第8天，在成牙本质细胞层以及赫特维希上皮根鞘区域观察到阳性染色。然而，在这个相同的时间点，在釉器或牙乳头细胞中未观察到2arN的阳性标记。到第15天，在牙周膜区域以及细胞外基质在牙本质上的初级沉积区域观察到OPN的阳性染色。还确定了纤连蛋白、OPN和牙本质涎蛋白（DSP）在体外促进牙外胚间充质细胞附着的能力。有趣的是，在没有黏附蛋白的情况下，这些细胞在细菌培养皿（对照）上附着得非常好。DSP并没有比对照细胞观察到的情况增加细胞附着。相比之下，纤连蛋白和OPN都增强了细胞附着。这些研究虽然是初步的，但表明OPN在根发育过程中以独特的方式表达，因此表明这种黏附蛋白在根形成过程中具有调节作用。
