Cyclic tensile stress effects on the expression of connective tissue growth factor in human periodontal ligament fibroblasts / 中国组织工程研究

ABSTRACT

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 culturedin vitro were given stimulation of cyclic tensile stress in vitro for 1, 6, 12, 24 hours using multi-channel cel stretch stress loading system (experimental group). Control group was set up and not given any stimulation at the same time. The cels 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.