Effects of sex hormones and aging on regeneration of periodontal tissue

牙周病治疗的主要目的是矿化和软结缔组织的再生。PDL细胞在体外可产生矿化结节，这是PDL细胞用于再生治疗的重要功能之一。本研究旨在探讨雌二醇对人牙周膜细胞矿化结节形成的影响。从健康供体获得PDL细胞，并将其维持在含10%胎牛血清的DMEM中。雌二醇的作用时，使用无血清培养基。用比色法分析超声破碎的细胞上清液中的ALP活性。通过用茜素红染色PDL细胞并计数结节数量来评估矿化结节的形成。与对照组相比，20 ng/ml的Escherichia coli显著增强ALP活性和矿化结节形成。这些结果表明，雌激素状态可能会改变牙周组织的再生活性。牙周膜（PDL）细胞是已知的具有成骨细胞样特征，并能够分化成骨细胞。由于人成骨细胞表达雌激素受体mRNA，PDL细胞也可能表达这些受体。然而，关于PDL细胞中雌激素受体mRNA的存在，有相互矛盾的研究结果。为了确定PDL细胞是否表达雌激素受体mRNA，使用两种不同的引物进行逆转录-聚合酶链反应（RT-PCR）。牙周膜（PDL）细胞从一个健康的前磨牙牙周膜提取正畸原因。人乳腺癌细胞系MCF 7用作阳性对照。雌激素受体mRNA在PDL细胞中的表达检测使用的引物之一相比，MCF 7强度较低。Southern杂交证实了这些结果。我们的研究结果表明，PDL细胞表达低水平的雌激素受体mRNA。

A primary objective in the treatment of periodontal disease is the regeneration of the mineralizec and soft connective tissue. PDL cells produce mineralized nodules in vitro which is one of the important functions of PDL cells for regenerative therapy. The purpose of this study was to investigate the effects of estradiol on mineralized nodule formation by human PDL cells. PDL cells were ob-tained from healthy donors and maintained in DMEM with 10% fetal bovine serum. Serum-free medium was used when the effects of estradiol were tested. ALP activity in the supernatant of cells disrupted by sonication was analyzed spectrophotometrically. The formation of mineralized nodules was assessed by staining the PDL cells with alizarine red and counting the number of nodules. at Estradiol 20 ng/ml significantly enhanced the ALP activity and mineralized nodule formation compared to the control. These results suggested that estrogen status may modify the regenerative activity of periodontal tissue.Periodontal ligament (PDL) cells are known to have osteoblast-like features and are capable of differentiating into osteogenic cells. As human osteoblasts express estrogen receptor mRNA, it is possible that PDL cells also express these receptors. However, conflicting findings have been reported regarding the presence of oestrogen receptor mRNA in PDL cells. To determine whethe PDL cells express oestrogen receptor mRNA, reverse transcriptase-polymerase chain reaction (RT-PCR) was performed using two different primers. Periodontal ligament (PDL) cells were obtained from a healthy periodontal ligament of premolar extracted for orthodontic reasons. The humar breast adenocarcinoma cell line MCF7 was used as a positive control. Expression of oestrogen receptor mRNA in PDL cells was detected using one of the primers with less intensity compared to MCF7. Southern hybridization confirmed these results. Our findings suggest that PDL cells express oestrogen receptor mRNA at low levels.