探討 BisGMA 刺激小鼠巨噬細胞產生 PGE2 與細胞毒性–經由COX-2、cPLA2、MAPK family 路徑之研究

Abstract

One of the materials, bisphenole-glycidyl methacrylate (BisGMA), recently has been point out in some studies which can cause cytoxicity, genotoxicity and inflammation in human dental pulp cells and macrophages. For instance, BisGMA induced the generating of proinflammatory cytokines such as tumor necrosis factor-α(TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). In particular, prostaglandin E2 (PGE2) plays an important role in immunomodulatory; however, the mechanism of BisGMA induces PGE2 activation in macrophage has not been clearly defined. Therefore, the purpose of this study is to evaluate the inductive effects of BisGMA induce PGE2 activation signal pathway in mice macrophage (RAW264.7). Throughout this experiment,enzyme-linked immunosorbent assay (ELISA) was used to confirm that BisGMA does increase PGE2 level in concentration-dependent manner. Furthermore, western blots were used to analysis the PGE2 protein phosphorylation levels: including cytosolic phospholipase A2 (cPLA2), cyclooxygenase-2 (COX-2) and also ERK1/2, JNK and p38 pathways in the MAPK pathway. The result shown that, BisGMA will activate, (1) extracellular-signal-regulated kinase 1/2 (ERK1/2) pathways including mitogen-activated protein kinase kinase 1/2 (MEK1/2), ERK1/2 and ETS domain-containing protein (Elk), (2) p38 pathway, including mitogen-activated protein kinase kinase 3/6 (MEK3/6), and MAPk-activated protein kinase 2 (MAPKAPK2), (3) JNk pathway, including mitogen-activated protein kinase kinase 4 (MEK4), c-Jun N-terminal kinase (JNK) and c-Jun, in dose-dependent manner. Pretreatment U0126 (ERK1/2 inhibitor), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor) and AACOCF3 (cPLA2 inhibitor), reconfirmed that BisGMA will induce the phosphorylation of ERK1/2、p38、JNK and cPLA2. As shown above, the generating of PGE2 was induced by BisGMA, which involved the phosphorylation of cPLA2 via ERK1/2, p38 and JNK pathways in RAW264.7 macrophages. Moreover, BisGMA caused DNA damage which activated by cysteine-aspartic proteases (caspase) 3、8、9 then led to apoptosis.