Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.24 (mitogen-activated protein kinase)
 95,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Triethylene glycol dimethacrylate (TEGDMA) is a resin monomer which is released from polymerized dental composite materials. It induced apoptosis in various target cells or inhibition of LPS-induced cytokine production in cells of the immune system after prolonged exposure. In these tissues, mitogen-activated protein kinases (MAPK) regulate signal transduction pathways that support cell survival and cytokine synthesis. The time-dependent regulation of MAPK as well as their linkage to the induction of apoptosis and cytokine release under the influence of resin monomers is unknown. It was the aim of the present study to investigate the kinetics of the up- or down-regulation of the MAPK p38, JNK, and ERK1/2, the induction of apoptosis and cytokine release in RAW264.7 mouse macrophages and human pulp-derived cells. ERK1/2, p38 and JNK were differentially activated by phosphorylation in the presence of lipopolysaccharide (0.1 microg/ml; LPS), a known inducer of MAPK activity, and TEGDMA (3 mM) as detected by Western blotting. In macrophages, ERK1/2 was activated about 6-fold by LPS, while no activation was observed in the presence of TEGDMA after 15 and 30 min. A slight activation of p38 was detected in cell cultures after short exposure to TEGDMA (30 min), but activated JNK was identified after LPS stimulation only. After a long 24 h exposure period, ERK1/2 and p38 were strongly activated by LPS, a combination of LPS/TEGDMA, and TEGDMA alone (15-20-fold). In human pulp-derived cells, ERK1/2 was phosphorylated after exposure to TEGDMA up to 2 h, and sustained activation of ERK1/2 as well as p38 (12-15-fold) was detected after prolonged exposure for 24 h. The LPS-induced, time-related increase in the secretion of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) as well as the anti-inflammatory IL-10 was instantaneously inhibited by TEGDMA in mouse macrophages. In parallel, the percentage of cells in macrophage cultures in the stage of apoptosis and necrosis increased with exposure period. Yet, in contrast to the inhibition of cytokine release, apoptosis and necrosis caused by LPS and TEGDMA was a late response in both mouse macrophages and human pulp-derived cells. From these data it appears as if MAPK activation, inhibition of cytokine release and the induction of apoptosis and necrosis by TEGDMA are tightly related. The direct causal correlation of these phenomena, however, requires further investigation.
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PMID:Resin monomer-induced differential activation of MAP kinases and apoptosis in mouse macrophages and human pulp cells. 2009 53

Triethylene glycol dimethacrylate (TEGDMA) is a resin monomer available for short exposure scenarios of oral tissues due to incomplete polymerization processes of dental composite materials. The generation of reactive oxygen species (ROS) in the presence of resin monomers is discussed as a common mechanism underlying cellular reactions as diverse as disturbed responses of the innate immune system, inhibition of dentin mineralization processes, genotoxicity and a delayed cell cycle. Yet, the signaling pathway through a network of proteins that finally initiates the execution of monomer-induced specific cell responses is unknown so far. The aim of the present study was to extend the knowledge of molecular mechanisms of monomer-induced cell death as a basis for reasonable therapy strategies. Thus, the monomer-induced expression and phosphorylation of stress-related transcription factors was analyzed in various cell lines. The time-related induction of apoptosis was investigated as well. The expression of p53 increased in HeLa cell cultures treated with camptothecin (positive control) for 24h, and the formation of p53Ser15 and p53Ser46 was detected in cell nuclei by Western blotting. TEGDMA (3 mm) appeared to stimulate p53 expression only slightly, but increased p21 expression was found in cell nuclei and cytoplasm. Both camptothecin and TEGDMA increased p53 expression to some extent in the nuclear fraction in human transformed pulp-derived cells (tHPC), and similar effects were detected in RAW264.7 macrophages. No clear induction of c-Jun and phospho-c-Jun by TEGDMA was detected in HeLa cell nuclei, and the expression of ATF-2 and phospho-ATF-2 was inhibited in the presence of the monomer. ATF-3 expression was found only in the nuclear fraction of camptothecin-treated HeLa cultures. TEGDMA seemed to inhibit the formation of phospho-c-Jun and phospho-ATF-2 in tHPC, and the monomer acted negatively on the expression of c-Jun, ATF-2 and ATF-3 in RAW264.7 macrophages. These changes in the expression and activation of stress-related transcription factors were time-related to the induction of apoptosis by TEGDMA in all cell lines. The present study provides experimental evidence that TEGDMA interferes with the regulation of cellular pathways through transcription factors activated as a consequence of DNA damage like p53 or initiated downstream of MAPK (mitogen-activated protein kinases) like c-Jun, ATF-2 and ATF-3. The direct causal correlation between DNA damage, activation or inhibition of MAPKs and transcription factors, and apoptosis is under current investigation. However, the induction of apoptosis in different cell lines in the presence of monomers like TEGDMA may be subject to a higher level of complexity than currently suggested by simple linear models.
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PMID:Activation of stress-regulated transcription factors by triethylene glycol dimethacrylate monomer. 2114 83