Effect of endothelin-1 on cyclooxygenase-2 gene expression and prostaglandin E2 synthesis in human periodontal fibroblasts

Abstract

The objective of this study is to clarify the effect of endothelin-1 on COX-2 mRNA expression and PGE2 production from human periodontal ligament fibroblasts. Effect of various concentration of ET-1 on cell viability of primary human periodontal ligament fibroblasts was determined by an MTT assay. Then, primary human periodontal ligament fibroblasts were treated with 10 pM ET-1 for 0.5, 1, 2, 4 hours to investigate the time-course effect. Furthermore, to investigate the dose-response effect, periodontal ligament fibroblasts were treated with 1, 10, 100 pM ET-1 for 1 hour. The untreated cells were set as control. RNA extraction followed by cDNA synthesis and real-time PCR were performed to assess COX-2 expression level. Enzyme-Linked Immunosorbent Assay along with micro BCA protein assay was performed to assess PGE2 production from the time-course experiment. One-way ANOVA followed by Games-Howell post-hoc analysis was used to analyze the difference between groups. The result showed that ET-1 significantly increased COX-2 expression in a time-dependent (P<0.05) but not dose-dependent manner. PGE2 level was also increased at 1 hour of ET-1 treatment, though not statistically significant. Further investigation is required to determine the effect of ET-1 in human periodontal ligament fibroblasts.