• BMB Reports
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• v.40 no.6
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• pp.1077-1082
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• 2007

Human glutamate dehydrogenase exists in hGDH1 (housekeeping isozyme) and in hGDH2 (nerve-specific isozyme), which differ markedly in their allosteric regulation. In the nervous system, GDH is enriched in astrocytes and is important for recycling glutamate, a major excitatory neurotransmitter during neurotransmission. Chloroquine has been known to be a potent inhibitor of house-keeping GDH1 in permeabilized liver and kidneycortex of rabbit. However, the effects of chloroquine on nerve-specific GDH2 have not been reported yet. In the present study, we have investigated the effects of chloroquine on hGDH2 at various conditions and showed that chloroquine could inhibit the activity of hGDH2 at dose-dependent manner. Studies of the chloroquine inhibition on enzyme activity revealed that hGDH2 was relatively less sensitive to chloroquine inhibition than house-keeping hGDH1. Incubation of hGDH2 was uncompetitive with respect of NADH and non-competitive with respect of 2-oxoglutarate. The inhibitory effect of chloroquine on hGDH2 was abolished, although in part, by the presence of ADP and L-leucine, whereas GTP did not change the sensitivity to chloroquine inhibition. Our results show a possibility that chloroquine may be used in regulating GDH activity and subsequently glutamate concentration in the central nervous system.

• BMB Reports
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• v.53 no.11
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• pp.576-581
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• 2020

Dimethylation of the histone H3 protein at lysine residue 9 (H3K9) is mediated by euchromatin histone methyltransferase II (EHMT2) and results in transcriptional repression of target genes. Recently, chemical inhibition of EHMT2 was shown to induce various physiological outcomes, including endoplasmic reticulum stress-associated genes transcription in cancer cells. To identify genes that are transcriptionally repressed by EHMT2 during apoptosis, and cell stress responses, we screened genes that are upregulated by BIX-01294, a chemical inhibitor of EHMT2. RNA sequencing analyses revealed 77 genes that were upregulated by BIX-01294 in all four hepatic cell carcinoma (HCC) cell lines. These included genes that have been implicated in apoptosis, the unfolded protein response (UPR), and others. Among these genes, the one encoding the stress-response protein Ras-related GTPase C (RRAGC) was upregulated in all BIX-01294-treated HCC cell lines. We confirmed the regulatory roles of EHMT2 in RRAGC expression in HCC cell lines using proteomic analyses, chromatin immune precipitation (ChIP) assay, and small guide RNA-mediated loss-of-function experiments. Upregulation of RRAGC was limited by the reactive oxygen species (ROS) scavenger N-acetyl cysteine (NAC), suggesting that ROS are involved in EHMT2-mediated transcriptional regulation of stress-response genes in HCC cells. Finally, combined treatment of cells with BIX-01294 and 5-Aza-cytidine induced greater upregulation of RRAGC protein expression. These findings suggest that EHMT2 suppresses expression of the RRAGC gene in a ROS-dependent manner and imply that EHMT2 is a key regulator of stress-responsive gene expression in liver cancer cells.

• Herbal Formula Science
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• v.13 no.1
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• pp.9-33
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• 2005

Acetaminophen, which causes acute liver min in humans and animals, has made useful inducer of hepatoxicity for studying hepatopreventive drugs. Injinhotang is known as one of the hepatopreventive drugs. However, its mechanism of recovery of hepatoxicity treated with acetaminophen is poorly understood. this study was performed to observe the antioxidative effect of injinhotang extract and its several combination groups. The results were obtained as follows:1. In the study on free radical scavenging effect in vitro(the suppressing effect on peroxidation of linoleic acid on concentration, the scavenging effect of DPPH radical, inhibitory effect of superoxide in xanthine-xanthine oxidase system and the inhibitory effect on lipid peroxidation reaction by hydroxy radical in H2O2-Fe2+system, injinhotang have more effect than its components groups relatively. 2. In the study on antioxidants system in vivo(the level of serum LPO, the level of hepatic LPO, catalase, GSH, GST), only injnhotang has a significant effect. 3. In the study on hepatotoxicity(GOT, GPT, $\gamma$-GTP, ALP, LDH, b ilirubin), only injinhotang has a significant effect. These results suggest that injinhotang has the protective effect on acetaminophen-induced hepatoxicity. The mechanisms of these are supposed to be involved in antioxidant and three drugs' cooperative synergy effect.

• BMB Reports
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• v.45 no.12
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• pp.707-712
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• 2012

Human glutamate dehydrogenase isozymes (hGDH1 and hGDH2) have been known to be inhibited by palmitoyl-CoA with a high affinity. In this study, we have performed the cassette mutagenesis at six different Cys residues (Cys59, Cys93, Cys119, Cys201, Cys274, and Cys323) to identify palmitoyl-CoA binding sites within hGDH2. Four cysteine residues at positions of C59, C93, C201, or C274 may be involved, at least in part, in the inhibition of hGDH2 by palmitoyl-CoA. There was a biphasic relationship, depending on the levels of palmitoyl-CoA, between the binding of palmitoyl-CoA and the loss of enzyme activity during the inactivation process. The inhibition of hGDH2 by palmitoyl-CoA was not affected by the allosteric inhibitor GTP. Multiple mutagenesis studies on the hGDH2 are in progress to identify the amino acid residues fully responsible for the inhibition by palmitoyl-CoA.

• Korean Journal of Pharmacognosy
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• v.40 no.3
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• pp.205-212
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• 2009

Antitumor activity of Korean mistletoe extract (KM-110) and European commercial mistletoe preparation (Helixor) was investigated. KM-110 showed the cytotoxic effect that it is high for various tumor cell lines and normal splenocytes in comparison with Helixor. Administration of two mistletoe extracts ($100{\mu}g$) to mice did not show any significant changes on the level of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvate transaminase (GTP), blood creatinine (CRE) and blood urea nitrogen (BUN) in sera. The culture supernatant of macrophages stimulated with KM-110 inhibited effectively tumor growth whereas Helixor had little effect. Administration of KM-110 or Helixor resulted in a effective inhibition of lung metastasis after the i.v. inoculation of colon 26-M3.1 lung carcinoma, B16-BL6 melanoma and L5178Y-ML25 lymphomas. In all cases, the mice treated with KM-110 showed more effective anti-tumor metastatic activity than the mice of Helixor. These results suggest that Korean mistletoe extracts, KM-110 might be used as an alternative methods having antitumor activity like European mistletoe preparation, Helixor.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.289-294
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• 2014

The purpose of this report is to discuss the obtained findings gathered from ultrasound screenings of the liver. After running diagnostic tests health, screens were then conducted to analyze and compare the gained results. This data was then charted and used to strengthen our theorized hypothesis. From January 2013 to June 2013 a recorded 2906 people over the age of 20 visited Health Promotion Centers in various areas throughout Daejeon. Of those 2906 participants 1789 underwent screenings for abdominal ultrasonography; these participants as well as their ultrasound results were used as the bases of our study. For the establishment of our baseline and the comparison of our results, we gathered case-controlled studies from various reputable sources. Both the control and the experimental groups were tested to measure the following liver enzymes (AST, ALT, r-GTP, ALP, and etc.). Kidney functions were measured as well enzymes such as BUN, Creatinine, and Uric Acids levels were analyzed and recorded to see if any relationships existed between the levels documented in the liver and those in the kidneys. It was shown that the two primary causes of fat build up within the liver were significantly connected to obesity BMI(OR=4.14) and waist circumference(OR=3.88).

• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.11-24
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• 2010

Objectives : This study was carried out to investigate the hepatoprotective effects of mixture with Hovenia dulcis Thunb (HDT) and Acer tegmentosum Maxim(ATM) on D-galactosamine-induced liver failure in rats. Methods : The animals were divided into 4 groups: control, with liver failure and no treatment; H1A1, with liver failure and oral treatment with HDT 1 and ATM 1; H1A2, with liver failure and oral treatment with HDT 1 and ATM 2; H1A4, with liver failure and oral treatment with HDT 1 and ATM 4. The animals were treated for 3 weeks and then examinations of change of body weight, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transpeptidase ($\gamma$-GTP), total cholesterol, triglyceride, total bilirubin, superoxide dismutase (SOD), catalase, histopathologic change, and complete blood count (CBC) were performed. Results : All experimental groups had significantly decreased AST in serum and markedly increased activity of SOD as compared with the control group. H1A1, and H1A4 significantly decreased ALT in serum and H1A4 at 2 weeks was significantly higher on the change of body weight as compared with the control group. In histopathologic change of liver tissue by light microscopy, all experimental groups showed recovery effects of liver cells which were damaged by D-galactosamine. Conclusions : Based upon these results, it could be assumed that a mixture of HDT and ATM has hepatoprotective and antioxidative effects on D-galactosamine-induced liver failure. Therefore, a mixture of HDT and ATM might be utilized as a protective agent in therapy for liver diseases.

• BMB Reports
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• v.38 no.4
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• pp.391-398
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• 2005

3-hydrogenwadaphnin (3-HK) is a new daphnane-type diterpene ester isolated from Dendrostellera lessertii with strong anti-tumoral activity in animal models and in cultures. Here, prolonged effects of this new agent on proliferation and viability of several different cancerous cell lines were evaluated. Using [$^3H$]thymidine incorporation, it was found that the drug inhibited cell proliferation and induced G1/S cell cycle arrest in leukemic cells 24 h after a single dose treatment. The cell viability of Jurkat cells was also decreased by almost 10%, 31% and 40% after a single dose treatment (7.5 nM) at 24, 48 and 72 h, respectively. The drug-treated cells were stained with acridine orange/ethidium bromide to document the chromatin condensation and DNA fragmentation. These observations were further confirmed by detection of DNA laddering pattern in the agarose gel electrophoresis of the extracted DNA from the treated cells. Treatment of K562 cells with the drug at 7.5, 15 and 30 nM caused apoptosis in 25%, 45% and 65% of the cells, respectively. Exogenous addition of $25-50\;{\mu}M$ guanosine and/or deoxyguanosine to the cell culture of the drug-treated cells restored DNA synthesis, released cell arrest at G1/S checkpoint and decreased the apoptotic cell death caused by the drug. These observations were not made using adenosine. However, the drug effects on K562 cells were potentiated by hypoxanthine. Based on these observations, perturbation of GTP metabolism is considered as one of the main reasons for apoptotic cell death by 3-HK.

• BMB Reports
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• v.46 no.2
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• pp.103-106
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• 2013

Phosphoinositide 3-kinases (PI3Ks) play key roles in synaptic plasticity and cognitive functions in the brain. We recently found that genetic deletion of $PI3K{\gamma}$, the only known member of class IB PI3Ks, results in impaired N-methyl-D-aspartate receptor-dependent long-term depression (NMDAR-LTD) in the hippocampus. The activity of RalA, a small GTP-binding protein, increases following NMDAR-LTD inducing stimuli, and this increase in RalA activity is essential for inducing NMDAR-LTD. We found that RalA activity increased significantly in $PI3K{\gamma}$ knockout mice. Furthermore, NMDAR-LTD-inducing stimuli did not increase RalA activity in $PI3K{\gamma}$ knockout mice. These results suggest that constitutively increased RalA activity occludes further increases in RalA activity during induction of LTD, causing impaired NMDAR-LTD. We propose that $PI3K{\gamma}$ regulates the activity of RalA, which is one of the molecular mechanisms inducing NMDAR-dependent LTD.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2743-2748
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• 2013

The vitamin gets through food and the sun. But there is case that density alters by certain factor in vitamin. So this research analyzed effect of the liver function factor and change of $25OH-VIT.D_3$ density. Research target is a person who undergo health medical examination in the certain university hospital medical examination center from August, 2012 to December, 2012. Comparison classified to experiment group and control group. As a result, variable that influence in $25OH-VIT.D_3$ density showed by age and B type inflammation of the liver titer. Specially, B type inflammation of the liver titer displayed reverse corelation ($R^2$=0.40). Therefore, inflammation of the liver carrier must manage liver fuction test and density of $25OH-VIT.D_3$.