AGE-DEPENDENT CHNGES OF MOLECULR INTERACTION IN PERIODONTAL TISSUEU.

我们先前研究了小鼠牙周组织中BrdU和TUNEL阳性细胞随年龄的变化，结果表明，由于细胞凋亡，与衰老相关的细胞成分在粘膜下结缔组织中显著减少。在此基础上，我们还观察了衰老过程中小鼠各器官组织的细胞动力学变化。出生后30周及以后，牙龈上皮层、颊粘膜、皮肤和毛囊中BrdU阳性细胞减少。生后20周及以后，牙周粘膜下组织、颌下腺粘液性和浆液性腺泡细胞TUNEL阳性细胞增多。衰老标志物蛋白-30(SMP-30)是一种与年龄相关的标志性蛋白，在脑和肝脏中均有表达。已知SMP-30与细胞中的抗凋亡活性有关。用RT-PCR方法检测SMP-30在出生后15周的小鼠牙周组织中的表达。此外，我们对10-15周龄的小鼠牙龈组织进行了cDNA消减，发现10周龄的68个基因和15周龄的51个基因存在差异表达。SMP-30和这些差异表达基因的分子相互作用现在正在进行中。

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.