• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.209-215
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• 2005

Recently, a large number of clinical experiments have shown that exposure of organic pollutants lead to various cancers through the abnormal cell growth. Environmental pollutants, such as 2, 3, 7, 8-Tetrachloro dibenzo-p-dioxin (TCDD) and polycyclic aromatic hydrocarbons (PAHs), are carcinogen and are known to cause the cognitive disability and motor dysfunction in the developing of brain. The effects of these pollutants on neurodevelopmental disorder is well established, but the underlying mechanism(s) and similarity of gene expression profiles in human brain tumors with organic pollutants still remain unclear. In this study, we first examined the gene expression profiles in glioblastomas compared with meningioma that are kinds of primary human brain tumor by using human cDNA microarray. The results of cDNA microarray analysis revealed that 26 genes were upregulated (Z-ratio>2.0) and 14 genes were downregulated (Z-ratio<-2.0) in glioblastoma compared with meningioma. From the altered gene patterns, mitogen-activated protein kinase (MAPK) signaling related genes, such as MAP2K3, MAP3K11 and jun activated domain binding protein, and transcription factors, such as UTF2 and TF12, were upregulated in glioblastoma. Also, we tried to investigate the relation between important genes up- and down-regulated in giloblastoma and various organic pollutants. Therefore, the identification of changes in the patterns of gene expression may provide a better understanding of the molecular mechanisms involved in human primary brain tumors and of the relation between gene expression profiles and organic pollutants in brain tissue.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.31-37
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• 2020

We previously identified a new heparinase inhibitor fungal metabolite, named CRM646-A, which showed inhibition of heparinase and telomerase activities in an in vitro enzyme assay and antimetastatic activity in a cell-based assay. In this study, we elucidated the mechanism by which CRM646-A rapidly induced nucleus condensation, plasma membrane disruption and morphological changes by increasing intracellular Ca²⁺ levels. Furthermore, PD98059, a mitogen-activated protein kinase (MEK) inhibitor, inhibited CRM646-A-induced nucleus condensation through ERK1/2 activation in rat 3Y1 fibroblast cells. We identified CRM646-A as a Ca²⁺ ionophore-like agent with a distinctly different chemical structure from that of previously reported Ca²⁺ ionophores. These results indicate that CRM646-A has the potential to be used as a new and effective antimetastatic drug.

• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.197-207
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• 2006

This experiment focused on MAPK activation in host cell invasion and replication of T. gondii, as well as the expression of CC chemokines, MCP-1 and $MIP-1\alpha$, and enzyme, COX-2/prostaglandin $E_2(PGE_2)$ in infected cells via western blot, $[^3H]-uracil$ incorporation assay, ELISA and RT-PCR. The phosphorylation of ERK1/2 and p38 in infected HeLa cells was detected at 1 hr and/or 6 hr postinfection (PI). Tachyzoite proliferation was reduced by p38 or JNK MAPK inhibitors. MCP-1 secretion was enhanced in infected peritoneal macrophages at 6 hr PI. $MIP-1\alpha$ mRNA was increased in macrophages at 18 hr PI. MCP-1 and $MIP-1\alpha$ were reduced after treatment with inhibitors of ERK1/2 and JNK MAPKs. COX-2 mRNA gradually increased in infected RAW 264.7 cells and the secretion of COX-2 peaked at 6 hr PI. The inhibitor of JNK suppressed COX-2 expression. $PGE_2$ from infected RAW 264.7 cells was increased and synthesis was suppressed by PD98059, SB203580, and SP600125. In this study, the activation of p38, JNK and/or ERK1/2 MAPKs occurred during the invasion and proliferation of T. gondii tachyzoites in HeLa cells. Also, increased secretion and expression of MCP-1, $MIP-1\alpha$, COX-2 and $PGE_2$ were detected in infected macrophages, and appeared to occur via MAPK signaling pathways.

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.23-29
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• 2011

Objective : The purpose of this study was to investigate the anti-inflammatory effects of aqueous extract from Scolopendrae Corpus (SC) on lipopolysaccharide (LPS)-induced inflammatory response. Methods : To evaluate the anti-inflammatory effects of SC, we examined the inflammatory mediators such as nitric oxide (NO) and pro-inflammatory cytokines (TNF-a, inteleukin (IL)-$1{\beta}$ and IL-6) on RAW 264.7 cells. We also examined molecular mechanisms such as mitogen-activated protein kinases (MAPKs) and inhibitory kappa B a ($I{\kappa}$-Ba) using western blot. Furthermore, we also investigated the effect of SC on LPS-induced endotoxin shock. Results : Extract from SC itself had not any cytotoxic effect in RAW 264.7 cells. Aqueous extract from SC inhibited LPS-induced NO production and iNOS expression. SC pre-treatment also inhibited IL-$1{\beta}$, IL-6 production in RAW 264.7 cells. To investigate inhibitory effects of SC on inflammatory mediators, activation of MAPKs was examined. SC inhibited the phosphorylation of p38 kinases (p38), c-Jun $NH_2$-terminal kinase (JNK) and also the degradation of $I{\kappa}$-$B{\alpha}$ in RAW 264.7 cells stimulated with LPS. Furthermore, SC administration reduced LPS-induced endotoxin shock. Conclusion : SC down-regulated LPS-induced production of inflammatory mediators through inhibition of activation of p38, JNK and degradation of $I{\kappa}$-$B{\alpha}$. Taken together, our results suggest that SC may be a beneficial drug against inflammatory diseases such as sepsis.

• Environmental Analysis Health and Toxicology
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• v.21 no.3 s.54
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• pp.275-282
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• 2006

In order to get insight into the mechanism of cadmium (Cd)-induced brain injury, we investigated the effects of Cd on the induction of COX-2 in bEnd.3 mouse brain endothelial cells. Cd induced COX-2 expression and $PGE_2$ release, which were attenuated by thiol-reducing antioxidant N-acetylcysteine (NAC) indicating oxidative components might contribute to these events. Indeed, Cd increased cellular reactive oxygen species (ROS) level and DNA binding activity of nuclear factor-kB (NF-kB), an oxidative stress sensitive transcription factor. Cd-induced $PGE_2$ production and COX-2 expression were significantly attenuated by Bay 11 7082, a specific inhibitor of NF-kB and by SB203580, a specific inhibitor of p38 mitogen activated protein kinase (MAPK). These data suggest that Cd induces COX-2 expression through activation of NF-kB and p38 MAPK, the oxidative stress-sensitive signaling molecules, in brain endothelial cells.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.39.1-39.15
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• 2020

Background: There are various Helicobacter species colonizing the stomachs of animals. Although Helicobacter species usually cause asymptomatic infection in the hosts, clinical signs can occur due to gastritis associated with Helicobacter in animals. Among them, Helicobacter pylori is strongly associated with chronic gastritis, gastric ulcers, and gastric cancers. As the standard therapies used to treat H. pylori have proven insufficient, alternative options are needed to prevent and eradicate the diseases associated with this bacterium. Cheonwangbosim-dan (CBD), a traditional herbal formula that is popular in East Asia, has been commonly used for arterial or auricular flutter, neurosis, insomnia, and cardiac malfunction-induced disease. Objectives: The present study investigated the antimicrobial effect of CBD on H. pylori-infected human gastric carcinoma AGS cells and model mice. Methods: AGS cells were infected with H. pylori and treated with a variety of concentrations of CBD or antibiotics. Mice were given 3 oral inoculations with H. pylori and then dosed with CBD (100 or 500 mg/kg) for 4 weeks or with standard antibiotics for 1 week. One week after the last treatment, gastric samples were collected and examined by histopathological analysis, real-time quantitative polymerase chain reaction, and immunoblotting. Results: Our results showed that CBD treatment of AGS cells significantly reduced the H. pylori-induced elevations of interleukin-8, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). In the animal model, CBD treatment inhibited the colonization of H. pylori and the levels of malondialdehyde, inflammation, proinflammatory cytokines, iNOS, and COX-2 in gastric tissues. CBD also decreased the phosphorylation levels of p38 mitogen-activated protein kinase family. Conclusions: This study suggests that CBD might be a prospective candidate for treating H. pylori-induced gastric injury.

• Journal of Life Science
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• v.30 no.1
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• pp.106-112
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• 2020

Aminoacyl tRNA synthetase complex interacting multifunctional protein 2 (AIMP2) is a scaffolding protein required for the assembly of multi-tRNA synthetase, and it can exert pro-apoptotic activity in response to DNA damage. In the presence of DNA damage, AIMP2 binds to mouse double minute 2 homolog (MDM2) to protect p53 from MDM2 attack. TGF-β signaling results in the nuclear translocation of AIMP2, whereby AIMP2 interacts with FUSE-binding protein, and, thus, suppresses c-myc. TNF receptor-associated factor 2 (TRAF2) is an important mediator between TNF-receptors 1 and 2 which are involved in the signaling of c-Jun N-terminal kinase (JNK), nuclear factor κB (NF-κB), and p38 mitogen-activated protein kinases (MAPKs). TRAF2 is required for the activations of JNK and NF-κB via TNF-α and the mediation of anti-apoptosis signaling. AIMP2 can also enhance pro-apoptosis in the TNF-α signaling. During this signaling, AIMP2 assists the association of E3 ubiquitin ligase, the cellular inhibitor of apoptosis protein 1 (c-IAP1) which is well known and responsible for the degradation of TRAF2. The formation of a complex among AIMP2, TRAF2, and c-IAP1 results in proteasome-mediated TRAF2 degradation. AIMP2 can induce apoptosis via downregulation of TRAF2 to interact directly in TNF-α signaling. This review provides new insight into the molecular mechanism responsible for AIMP2 and TRAF2 complex formation and treatments for TNFα-associated diseases.

• Journal of Photoscience
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• v.9 no.2
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• pp.229-232
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• 2002

There are two distinct UV-responsive signaling pathways in UV-irradiated mammalian cells, i.e., the DNA damage-dependent and -independent pathways. The former occurs in nucleus and results in growth arrest and apoptosis via post-translational modification of p53. The latter is initiated by oxidative stress and/or by damages in cell membrane or cytoplasm, which activate signaling cascade through intracellular molecules including mitogen activated protein kinases (MAPK). In normal human fibroblastic cells, all of MAPK family members, extracellular signal-related kinases (ERK), c-Jun N-terminal kinases (JNK) and p38, were rapidly phosphorylated following UV-irradiation. ERK phosphorylation was suppressed by an inhibitor of receptor tyrosine kinases (RTK). As ERK usually responds to mitogenic stimuli from RTK ligands, UV-induced ERK phosphorylation may be linked to the proliferation of survived cells. In contrast, phosphorylation of JNK and p38, as well as apoptosis, were modulated by the level of UV-generated oxidative stress Therefore, JNK and p38 may take part in oxidative stress-mediated apoptosis. Phosphorylation of p53 at Ser and Thr residues are essential for stabilization and activation of p53. Among several sites reported, we confirmed phosphorylation at Ser-15 and Ser-392 after UV-irradiation. Both of these were inhibited by a phosphoinositide 3-kinase inhibitor, presumably due to the shutdown of signals from DNA damage to p53. Phosphorylation at Ser-392 was also sensitive to an antioxidant and a p38 inhibitor, suggesting that Ser-392 of p53 is one of the possible points where DNA damage-dependent and -independent apoptic signals merge. Thus, MAPK pathway links UV-induced intracellular signals to the nuclear responses and modifies DNA damage-dependent cellular outcome, resulting in the determination of cell death.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.700-709
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• 2016

The mitogen-activated protein kinase HOG1 (high-osmolarity glycerol response pathway) plays a crucial role in the response of yeast to hyperosmotic shock. Trichosporonoides oedocephalis produces large amounts of polyols (e.g., erythritol and glycerol) in a culture medium. However, the effects of HOG1 gene knockout and environmental stress on the production of these polyols have not yet been studied. In this study, a To-HOG1 null mutation was constructed in T. oedocephalis using the loxP-Kan-loxP/Cre system as replacement of the targeted genes, and the resultant mutants showed much smaller colonies than the wild-type controls. Interestingly, compared with the wild-type strains, the results of shake-flask culture showed that To-HOG1 null mutation increased erythritol production by 1.44-fold while decreasing glycerol production by 71.23%. In addition, this study investigated the effects of citric acid stress on the T. oedocephalis HOG1 null mutants and the wild-type strain. When the supplementation of citric acid in the fermentation medium was controlled at 0.3% (w/v), the concentration of erythritol produced from the wild-type and To-HOG1 knockout mutant strains improved by 18.21% and 21.65%, respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.4
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• pp.227-235
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• 2004

The aim of the present study was to examine the effect of leptin on CA release from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. Leptin $(1{\sim}100\;ng/ml)$, when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced a dose-dependently the secretory responses of CA evoked by ACh $(5.32{\times}10^{-3}\;M)$, DMPP $(10^{-4}\;M)$ and McN-A-343 $(10^{-4}\;M)$, although it alone has weak effect on CA secretion. However, it did not affect the CA secretion evoked by excess $K^+\;(5.6{\times}10^{-2}\;M)$. Leptin alone produced a weak secretory response of the CA. Moreover, leptin (10 ng/ml) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type $Ca^{2+}$ channels, and cyclopiazonic acid, an inhibitor of cytoplasmic $Ca^{2+}$ ATPase. However, in the presence of U0126 $(1\;{\mu}M)$, an inhibitor of mitogen-activated protein kinase (MAPK), leptin no longer enhanced the CA secretion evoked by ACh and DMPP. Furthermore, in the presence of anti-leptin (10 ng/ml), an antagonist of Ob receptor, leptin (10 ng/ml) also no longer potentiated the CA secretory responses evoked by DMPP and Bay-K-8644. Collectively, these experimental results suggest that leptin enhances the CA secretion from the rat adrenal medulla evoked by cholinergic stimulation (both nicotininc and muscarinic receptors), but does not that by membrane depolarization. It seems that this enhanced effect of leptin may be mediated by activation of U0126-sensitive MAPK through the leptin receptors, which is probably relevant to the activation of the dihydropyridine L-type $Ca^{2+}$ channels located on the rat adrenomedullary chromaffin cells.