Objective: To investigate the role of growth arrest-specific protein 6 (Gas6) in the process of the migration and osteogenic differentiation of human periodontal ligament cells (hPDLCs).
Methods: After different concentrations of recombinant human Gas6 (rhGas6) were added to hPDLCs, cell prolife-ration experiment (CCK-8) was taken to observe the effect of rhGas6 on hPDLCs cell proliferation. Scratch test and cell migration test (Transwell) were taken to analyze the migratory ability of hPDLCs in different concentrations of rhGas6 groups. After osteogenic induction, real-time quantitative polymerase chain reaction (real-time PCR) was taken to detect the expression of the Runt-related transcription factor 2 (Runx2) and alkaline phosphatase (ALP). ALP staining was used to detect the amount of mineralized nodules.
Results: After adding different concentrations of rhGas6, there were no statistically significant differences in hPDLCs cell proliferation among the experimental groups and the control group at 24, 48 and 72 hours (P>0.05). After 24 h of scratch, the healing area in the 800 μg/L of the rhGas6 group was greater than that in the control group, but without statistically significant difference (31.06%±13.70% vs. 21.79%±9.51%, P>0.05). In the migration test, after 24 h, the number of hPDLCs cells which penetrated through the membrane in the 800 μg/L rhGas6 group was significantly higher than that in the control group (P < 0.01). After rhGas6 was added and osteogenic induction, Runx2 and ALP gene expressions of hPDLCs in the 800 μg/L group were significantly higher than those in the control group (1.60±0.30 vs. 0.91±0.10, 2.81±0.61 vs. 0.86±0.12, P < 0.01). After Gas6 was knocked down, the ALP expression of hPDLCs was significantly lower than that of the control group (0.39±0.07 vs. 0.92±0.14, P < 0.01). There was no significant change in Runx2 expression (P>0.05). After 7 days of osteogenic induction, the mineralized nodules formed in the Gas6 knockdown group were significantly less than those in control group (0.25±0.04 vs. 1.00±0.11, P < 0.001). After 14 days of induction, the staining degree of the Gas6 knockdown group was lower than that of the control group, but there was no significant difference (0.86±0.04 vs. 1.00±0.16, P>0.05).
Conclusion: After downregulation of Gas6 gene, mineralized nodule formation was reduced and ALP gene expressions were decreased in the early stage of osteogenic induction (7 days). After addition of rhGas6, Runx2 and ALP gene expressions were increased and the number of cell migration was increased, suggesting that Gas6 might play a promoting role in the migration and osteogenic differentiation of human periodontal ligament cells.
目的: 探索广泛型侵袭性牙周炎(generalized aggressive periodontitis，GAgP)患者牙根形态异常与骨代谢或牙根发育相关基因多态性的关联。
方法: 纳入179例GAgP患者，平均(27.23±5.19)岁，男:女=67 : 112，平均存留牙数(26.80±1.84)颗。采用基于基质辅助激光解吸电离飞行时间质谱技术进行9个与骨代谢和牙根发育相关基因的13个单核苷酸多态性位点(single nucleotide polymorphisms，SNPs)的基因型检测。采用全口根尖片评判牙根形态异常，包括锥根、细长根、冠根比例失调、弯曲根、融合根、后牙根形态异常，分析13个SNPs位点不同基因型根形态异常牙的数量及发生率。
结果: GAgP患者根形态异常牙构成比为14.49%(695/4 798颗)，平均(3.88±3.84)颗。维生素D受体(vitamin D receptor，VDR)基因rs2228570位点的CC、CT、TT基因型患者根形态异常牙数量分别为(4.66±4.10)、(3.71±3.93)和(2.68±2.68)颗，CC基因型和TT基因型之间差异有统计学意义(t=2.62，P=0.01)。降钙素受体(calcitotin receptor，CTR)基因rs2283002位点CC、CT、TT基因型患者根形态异常数分别为(5.02±3.70)、(3.43±3.95)、(3.05±3.12)颗，CC基因型的根形态异常发病率高于CT和TT基因型(87.86% vs. 65.26%和63.64%，P=0.006，adjusted OR=3.71，95%CI:1.45~9.50)。
结论: VDR rs2228570及CTR rs2283002位点可能与广泛型侵袭性牙周炎患者牙根形态异常的发生有关，值得进一步研究。
Keywords: Alkaline phosphatase; Cell differentiation; Growth arrest-specific protein 6; Osteogenesis; Periodontal ligament.