Effect of TGF-beta1 on Collagen Turn-over, Prostaglandin E2, and Cyclooxygenase-2 in Human Dental Pulp Cells

• Main Authors: Po-Shuen Lin, 林柏萱
• Other Authors: 鄭景暉
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/447yu6

博士 === 國立臺灣大學 === 臨床牙醫學研究所 === 105 === Aim: TGF-β1 is an important growth factor which shown to influence odontoblast differentiation and matrix deposition in reactionary dentinogenesis during dental caries. TGF-β1 exerts its effects through many signaling pathways, such as SMADs and MAPKs. In this study, there are two parts investigating effects of TGF-β1on pulpal repair and regeneration. In the first part, we investigated the differential signaling pathways responsible for effects of TGF-β1 on collagen turnover, metalloproteinase-3 (MMP-3) and tissue inhibitor metalloproteinase-1 (TIMP-1) production in human dental pulp cells. In the second part of this study, we investigated the relationships between TGF-β1, cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2), two important proinflammatory cytokines of pulpal inflammation in in human dental pulp cell and further clarify the differential signaling transduction pathways of TGF-β1 that influence COX-2 production. Materials and Methods: Pulp cells were exposed to TGF-β1 with/without pretreatment of SB431542 (an ALK5/Smad2/3 inhibitor) and U0126 (a MEK/ERK inhibitor). In the first part of this study, sircol collagen assay was used to measure cellular collagen content. Culture medium pro-collagen I, TIMP-1 and MMP-3 levels were determined by enzyme-linked immunosorbant assay (ELISA). In the second part of this study, ELISA was used for measurement of PGE2 levels. RT-PCR and western blot were used to determined COX-2 mRNA and protein, respectively. Results: TGF-β1 increased the collagen content, pro-collagen I and TIMP-1 production, but slightly decreased MMP-3 production of pulp cells. SB431542 and U0126 prevented the TGF-β1-induced increase of collagen content and TIMP-1 production of dental pulp cells. Exposure to TGF-β1 (1-10 ng/ml) increased the COX-2 level of cultured pulp cells. Exposure to TGF-β1 (0.1-10 ng/mL) significantly increased PGE2 level in dental pulp cells. Under the pretreatment of SB431542, the stimulatory effect of TGF-β1 on COX-2 level of pulp cells was inhibited. Similarly, U0126 also partly inhibited the TGF-β1-induced COX-2 expression. Conclusion: TGF-β1 may be involved in the healing/regeneration processes of dental pulp in response to injury by stimulation of collagen and TIMP-1 production. These events are associated with ALK5/Smad2/3 and MEK/ERK signaling. TGF-β1 increased the COX-2 and PGE2 level of cultured pulp cells. This effect was associated with ALK5/Smad2/3 and MEK/ERK pathways. These events are important in the early inflammation, repair and regeneration of dental pulp in response to injury.