Profiles of gene expression on periodontal ligament cells

为了确定基因在牙周膜细胞上的特异性表达，我们分析了单细胞克隆细胞刺激后基因表达的变化。我们仅用普通培养基制备了少量单细胞培养的人牙周膜细胞。然后，我们必须在培养基中添加一些生长因子，以保持长期培养。我们分析了成纤维细胞生长因子-2 （FGF-2）对人牙周细胞增殖和复制能力的影响。在对数生长的细胞上添加FGF-2可使细胞增殖率提高10 ~ 15%。在有限的稀释方法中，FGF-2也增强了培养细胞的集落形成能力。这些影响在年轻细胞和年老细胞之间没有变化，并且在培养细胞的整个生命周期中都是一样的。我们分析了FGF-2在连续长期细胞培养中对细胞增殖能力的影响。FGF-2的添加在生命早期促进细胞增殖，但在生命晚期抑制细胞增殖。总的来说，FGF-2的添加导致了复制能力的下降。我们还采用半定量RT-PCR方法检测了p53和p16基因在不同生命周期培养细胞中的表达水平，在细胞中未发现显著差异。这些结果表明，FGF-2在长期培养过程中具有逆转作用，FGF-2是几种细胞的有效丝裂原。

In order to determine specific gene expression on periodontal ligament cells, we analyzed the change of gene expression after stimulation against the cloned cells that were derived from single-cell. We only prepared limited amount of human periodontal ligament cells which were derived from single-cell by using popular media. Then we had to add several growth factors,into media to maintain long term-culture. We analyzed the effects of fibroblast growth factor-2 (FGF-2) on proliferation and replicative capacity in human periodontal cells. Addition of FGF-2 on logarithmically growing cell enhanced proliferation of cell number by 10 to 15 %. FGF-2 also enhanced colony forming capacities on cultured cells in the limited dilution methods. These effects did not change between young and old cells, and suggested same throughout the life-span of cultured cells. We analyzed the effect on FGF-2 to replicative capacity in continuous long-term cell culture. Addition of FGF-2 enhanced proliferation in early stage of life-span, however, it caused inhibition of proliferation at late stage of life span. Totally, addition of FGF-2 caused decreased replicative capacity. We also determined gene expression levels of p53 and p16 into the cultured cells at different stage of life-span by semi-quantified RT-PCR method, and identified no significant differences into the cells. These results suggest that FGF-2, which was known a potent mitogen for several kind of cells, has reverse effect during long-term culture.