Effects of Enamel Matrix Derivative and Transforming Growth Factor-β1 on Connective Tissue Growth Factor in Human Periodontal Ligament Fibroblasts

Background: Enamel matrix derivative (EMD) is suggested to stimulate transforming growth factor-β (TGF-β) production. Connective tissue growth factor (CTGF) is a downstream mediator of TGF-β. This study explores the effects of EMD and TGF-β1 on CTGF in periodontal ligament (PDL) fibroblasts and their interactions in PDL proliferation and development.Methods: Human PDL cells were stimulated with EMD. To explore the effects of EMD and TGF-β1 on CTGF expression, cells were treated with and without TGF-β inhibitor, and CTGF protein levels were assayed by Western blot analysis. To study the role of CTGF in PDL development, cells were treated with CTGF inhibitor. DNA synthesis was analyzed by bromodeoxyuridine enzyme-linked immunosorbent assay. Reverse-transcription polymerase chain reaction was performed to examine messenger RNA expression of PDL osteoblastic differentiation markers: type I collagen, alkaline phosphatase, and osteocalcin.Results: EMD induced a concentration-dependent increase of CTGF protein e...