周期性张应力下人牙周膜成纤维细胞结缔组织生长因子的表达

背景：前期研究发现，周期性张应力在一定时间内可以诱导人牙周膜成纤维细胞增殖。目的：观察周期性张应力对人牙周膜成纤维细胞表达结缔组织生长因子的影响；明确JNK、p38MAPK、PI3K信号通路在周期性张应力诱导人牙周膜成纤维细胞表达结缔组织生长因子过程中的作用。方法：采用多通道细胞牵张应力加载系统对体外培养的人牙周膜成纤维细胞分别给予周期性张应力刺激1，6，12，24 h，并以未加力组为对照组。对加力12 h的细胞分别添加JNK、p38MAPK、PI3K信号通路特异性抑制剂预处理，并与未加抑制剂的细胞作对比。应用ELISA法检测培养细胞分泌到上清液中的结缔组织生长因子蛋白；应用荧光定量PCR技术检测细胞结缔组织生长因子mRNA的表达。结果与结论：加载周期性张应力组与对照组相比较，1 h人牙周膜成纤维细胞表达结缔组织生长因子开始增强、6 h表达明显增强，12 h达最高峰值、24 h表达开始下降。加入JNK信号通路特异性抑制剂后，人牙周膜成纤维细胞表达结缔组织生长因子出现下降；而加入p38MAPK信号通路和PI3K信号通路的特异性抑制剂后结缔组织生长因子表达未发生明显改变。提示在一定时间范围内，周期性张应力引起结缔组织生长因子mRNA与蛋白水平的表达与时间呈依赖性升高；其后随着时间的延长，结缔组织生长因子的表达则开始下降。周期性张应力通过JNK通路的介导调控人牙周膜成纤维细胞结缔组织生长因子的表达。中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Cyclic tensile stress effects on the expression of connective tissue growth factor in human periodontal ligament fibroblasts

BACKGROUND:Previous studies have found that cyclic tensile stress can induce the proliferation of human periodontal ligament fibroblasts in a certain time.OBJECTIVE:To observe the effect of cyclic tensile stress on the expression of connective tissue growth factor in human periodontal ligament fibroblasts, and to clarify the role of JNK, p38MAPK, PI3K pathway in the cyclic tensile stress-induced expression of connective tissue growth factor in human periodontal ligament fibroblasts. METHODS:Human periodontal ligament fibroblasts cultured in vitro were given stimulation of cyclic tensile stress in vitro for 1, 6, 12, 24 hours using multi-channel cell stretch stress loading system (experimental group). Control group was set up and not given any stimulation at the same time. The cells under stress application for 12 hours were given specific inhibitors of JNK, p38MAPK, PI3K respectively at the beginning, and were compared with those with no inhibitors. The concentrations of connective tissue growth factor in the culture supernatant were measured by ELISA. The mRNA expression of connective tissue growth factor in human periodontal ligament fibroblasts was detected by real-time RT-PCR.RESULTS AND CONCLUSION:Compared with the control group, the expression of connective tissue growthfactor in human periodontal ligament fibroblasts under cyclic tensile stress began to increase at 1 hour, increased manifestly at 6 hours, reached the peak at 12 hours, and then decreased at 24 hours. The expression of connective tissue growth factor was reduced by the specific inhibitors of JNK, while the specific inhibitors of p38 MAPK, PI3K had not the same effect. In a certain time, the cyclic tensile stress can induce a time-dependent increase in mRNA and protein levels of connective tissue growth factor. Along with the extending of time, the expression of connective tissue growth factor begins to decrease. Cyclic tensile stress can regulate expression of connective tissue growth factor in human periodontal ligament fibroblasts via the JNK pathway.