Age-related Change of the Immunohistochemical Localization of Fibronectin and Laminin in association with the Apical Migration of the Junctional Epithelium

随着年龄的增长，牙周组织呈现出多种形态变化。这些变化的一个典型的例子是接合上皮的顶端迁移。采用免疫荧光和免疫电镜方法研究了纤维连接蛋白（FN）和层粘连蛋白（LN）在小鼠体内的分布，以阐明这些蛋白在连接上皮顶端迁移过程中可能的功能作用。小鼠在20周龄时开始顶端迁移，然后随着年龄的增长而发展，直到小鼠达到80周龄。在连接上皮的顶端，在上皮下纤维基质中可见FN，这一现象先于连接上皮的顶端迁移进展。FN也被证明与上皮细胞和基底膜之间的局灶接触的基质侧有关。因此，这种局灶性接触被认为是FN受体。LN的定位与结界上皮的迁移没有明显的关系。这些结果表明，FN为接合上皮的顶端迁移提供了临时基质。同时，LN在根尖迁移中似乎不起主要作用。

Periodontal tissue shows various morphological changes with aging. A typical example of these changes is the apical migration of the junctional epithelium. The distribution of fibronectin (FN) and laminin (LN) was investigated by means of immunofluorescent and immunoelectron microscopic methods in mice to clarify any possible functional roles of these proteins in the progression of apical migration of the junctional epithelium. Apical migration starts in 20-week-old mice, and then progresses with increasing age until the mice reached 80 weeks. In the apical tip of the junctional epithelium, FN was demonstrated in the subepithelial fibrillar matrix, and this phenomenon preceded the progression of apical migration in the junctional epithelium. FN was also demonstrated in association with the stromal side of the focal contact observed between epithelial cells and the basement membrane. Therefore, this focal contact is presumed to be a FN receptor. No apparent relationship between the localization of LN and the migration of the junctional epithelium was observed. These results suggest that the FN provides a provisional matrix for the apical migration of the junctional epithelium. Meanwhile, LN does not appear to play a major role in apical migration.