Abiko Y, Shimizu N, Yamaguchi M, Suzuki H, Takiguchi H
Department of Biochemistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Ann Periodontol. 1998 Jul;3(1):350-69. doi: 10.1902/annals.1998.3.1.350.
Although the severity of periodontal disease is known to be affected by age, functional changes of periodontal tissue cells during the aging process are not well characterized. It is important to define how cellular aging affects the progression of periodontal diseases associated with the aging process. In vitro aging of human gingival fibroblast (HGF) and periodontal ligament fibroblast (HPLF) cells was prepared by sequential subcultivations (5 to 6 passages as young, 18 to 20 passages as old). GFs were also prepared from gingiva of Down's syndrome patients and 60-week-old rats. Fetal rat calvarial osteoblasts were prepared by sequential digestion with collagenase. HGF and HPLF cells were treated with lipopolysaccharide (LPS) and cyclic tension force, respectively. Amounts of PGE2, interleukin (IL)-1 beta, IL-6, and plasminogen activator (PA) in conditioned media were measured. Total RNA was extracted, and mRNA expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR). LPS-stimulated PGE2, IL-1 beta, IL-6, and PA production was increased in "old" HGF compared to younger cells. According to RT-PCR analysis, gene expression of COX-2, IL-1 beta, IL-6, and tissue type (t) PA was higher in old cells than in young cells. Cyclic tension force to HPLF also stimulated phenotypic and gene expression of IL-1 beta, PGE2 (COX-2 gene) and tPA. These findings suggest that aging in both HGF and HPLF may be an important factor in the severity of periodontal disease through higher production of inflammatory mediators in response to both LPS and mechanical stress. In addition, oxygen radical-treated fibronectin (FN) as substratum diminished bone nodule formation by osteoblasts when compared with intact FN. This finding suggests that FN plays an important role in Osteoblast activity and that FN damaged by oxygen radicals during the aging process may be related to less bone formation.
虽然已知牙周病的严重程度会受到年龄的影响，但牙周组织细胞在衰老过程中的功能变化尚未得到充分表征。明确细胞衰老如何影响与衰老过程相关的牙周病进展非常重要。通过连续传代培养（5至6代作为年轻细胞，18至20代作为衰老细胞）制备人牙龈成纤维细胞（HGF）和牙周膜成纤维细胞（HPLF）的体外衰老模型。生长因子（GFs）也从唐氏综合征患者的牙龈和60周龄大鼠的牙龈中制备。通过胶原酶连续消化制备胎鼠颅骨成骨细胞。分别用脂多糖（LPS）和循环张力处理HGF和HPLF细胞。测量条件培养基中前列腺素E2（PGE2）、白细胞介素（IL）-1β、IL-6和纤溶酶原激活剂（PA）的含量。提取总RNA，并通过逆转录聚合酶链反应（RT-PCR）分析mRNA表达。与年轻细胞相比，“衰老”的HGF中LPS刺激的PGE2、IL-1β、IL-6和PA产生增加。根据RT-PCR分析，衰老细胞中环氧合酶-2（COX-2）、IL-1β、IL-6和组织型（t）PA的基因表达高于年轻细胞。对HPLF施加循环张力也刺激了IL-1β、PGE2（COX-2基因）和tPA的表型和基因表达。这些发现表明，HGF和HPLF的衰老可能是导致牙周病严重程度增加的一个重要因素，因为它们在对LPS和机械应力的反应中会产生更多的炎症介质。此外，与完整的纤连蛋白（FN）相比，经氧自由基处理的FN作为底物会减少成骨细胞形成骨结节。这一发现表明FN在成骨细胞活性中起重要作用，并且在衰老过程中被氧自由基损伤的FN可能与较少的骨形成有关。
