AGE-DEPENDENT CHNGES OF MOLECULR INTERACTION IN PERIODONTAL TISSUEU.

我们之前研究了小鼠牙周组织中BrdU阳性细胞和tunel阳性细胞的年龄依赖性变化，发现与衰老相关的细胞成分在粘膜下结缔组织中因细胞凋亡而显著减少。在此基础上，我们还研究了衰老小鼠各器官组织的细胞动力学变化。出生后30周及以后，牙龈上皮、颊黏膜、皮肤和毛囊brdu阳性细胞减少。出生后20周及以后，牙龈粘膜下组织、颌下腺粘液和浆液腺泡细胞均出现tunel阳性细胞增多。因此，在牙龈组织中，细胞动力学的年龄依赖性变化是明显的，因此似乎与牙龈衰退有关。衰老标记蛋白-30（senescence marker protein-30, SMP-30）是一种与年龄相关的标记蛋白，已知在大脑和肝脏中表达。已知SMP-30与细胞的抗凋亡活性有关。我们采用RT-PCR检测了出生后15周小鼠牙龈组织中SMP-30的表达。此外，我们对10 - 15周龄小鼠牙龈组织进行cDNA减法，发现10周有68个基因差异表达，15周有51个基因差异表达。SMP-30与这些差异表达基因的分子相互作用正在进行中。

We previously examined the age-dependent change of BrdU- and TUNEL-positive cells in the mouse periodontal tissue, and showed that a significant decrease of cellular component in association with aging occurred in the submucosal connective tissue caused by apoptosis. Based on this result, we also examined the cell kinetic change of various organs and tissues in mouse with aging. Decrease of BrdU-positive cells was observed in the epithelial layer of gingiva, buccal mucosa, skin and hair follicle at 30 weeks and following ages after birth. Meanwhile, increase of TUNEL-positive cell was demonstrated gingival submucosal tissue, and mucinous and serous acinar cells of submandibular gland at 20 weeks and following ages after birth. Thus age dependent change of the cell kinetic is evident in the gingival tissue, and is therefore seemed to be related with gingival recession.Senecent marker protein-30(SMP-30) is age-related marker protein, and is known to be expressed in brain and liver. SMP-30 is known to be related the apoptosis-resistant activity in cells. We examined the expression of SMP-30 in the mouse gingival tissue at 15 weeks after birth by RT-PCR. Furthernmore, we performed cDNA subtraction between 10 and 15 weeks aged mouse gingival tissue, and found that 68 genes in the 10 weeks, and 51 genes in the 15 weeks, were differentially expressed. Molecular interaction of SMP-30 and these differentially expressed genes are now proceeding.