内皮素B受体激动剂对小鼠成牙骨质细胞生物学行为的影响

目的：探讨内皮素B受体（ETBR）激动剂对成牙骨质细胞系OCCM-30生物学行为的影响，为牙源性牙根修复提供实验依据。方法：选取对数生长期的小鼠成牙骨质细胞，分为实验组和对照组。实验组采用10^-6 mol·L^-1 ETBR激动剂处理成牙骨质细胞，以未处理的细胞为对照组。采用MTT方法检测培养不同时间点（24、48和72h）2组成牙骨质细胞增殖抑制率，流式细胞术检测培养不同时间点（24、48和72h）2组细胞凋亡率，碱性磷酸酶染色和茜素红染色检测细胞体外分化及矿化情况，实时定量PCR检测各组细胞中Runx2、BSP、OCN、Col1和Osterix等分化相关基因表达水平。结果：MTT检测，与对照组比较，培养24、48和72 h后，实验组细胞增殖抑制率明显升高（P<0.05），培养48 h时细胞增殖抑制率最高。流式细胞术检测，与对照组比较，实验组成牙骨质细胞凋亡率无明显变化。碱性磷酸酶和茜素红染色检测，与对照组比较，实验组细胞显色较浅，产生矿化结节较少。实时定量PCR检测，与对照组比较，在培养24h时实验组细胞中Runx2、BSP、Osterix、OCN和Col1表达水平无明显变化，在培养48h时上述基因表达水平开始降低，在培养72h时细胞中Runx2、BSP、Osterix和Col1表达水平明显降低（P<0.01）。结论：ETBR激动剂可抑制成牙骨质细胞增殖和分化，但对细胞凋亡无影响。

Effects of endothelin B receptor agonist on biological behaviors of cementoblasts of mice

Objective: To investigate the effects of endothelin B receptor (ETBR) agonist on the biological behaviors of cementoblast cell line OCCM-30 of the mice, and to provide the experimental basis for odontogenic root restoration.Methods: The cementoblasts of the mice in logarithmic growth phase were selected and divided into experiment group and control group. The cells in experiment group were treated with ETBR agonist at a concentration of 10^-6 mol·L^-1, and the cells in control group did not receive any treatment. MTT method was used to detect the inhibitory rates of proliferation of the cementoblasts in two groups at different time points (24,48, and 72 h). Flow cytometry was used to detect the apoptotic rates of cells in two groups different time points (24, 48, and 72 h);alkaline phosphatase staining and alizarin red staining were performed to detect the cell differentiation and mineralization;real-time PCR was used to determine the expression levels of differentiation-related or mineralization-related genes such as Runx2, BSP, OCN, Col1, and Osterix.Results: MTT assay showed that compared with control group, the inhibitory rates of proliferation of the cells in experimental group were significantly increased after cultured for 24, 48 and 72 h(P<0.05), and the inhibitory rate of proliferation was the highest at 48 h of culture.The flow cytometry results showed that compared with control group, the apoptotic rate of cementoblasts in experimental group did not change significantly.In alkaline phosphatase and alizarin red staining experiments, compared with control group, the cells in experiment group showed lighter color rendering and fewer mineralized nodules.In real-time PCR detection, compared with control group, there were no significant differences in the expression levels of Runx2, Osterix, BSP, OCN and Col1 in the cells in experiment group at 24 h after culture, and the expression levels of Runx2, Osterix, BSP, OCN and Col1 in experiment group were decreased at 48 h after culture;at 72 h after culture, the expression levels of Runx2, Osterix, BSP and Col1 in experiment group were significantly decreased(P<0.01).Conclusion: ETBR agonist can inhibit the proliferation and differentiation of cementoblasts, but it has no effect on apoptosis.