• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.439-447
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• 2018

The aromatic compound p-hydroxybenzoate (PHBA) is an important material with multiple applications, including as a building block of liquid crystal polymers in chemical industries. The cytochrome P450 (CYP) enzymes are beneficial monooxygenases for the synthesis of chemicals, and CYP53A15 from fungus Cochliobolus lunatus is capable of executing the hydroxylation from benzoate to PHBA. Here, we constructed a system for the bioconversion of benzoate to PHBA in Escherichia coli cells coexpressing CYP53A15 and human NADPH-P450 oxidoreductase (CPR) genes as a redox partner. For suitable coexpression of CYP53A15 and CPR, we originally constructed five plasmids in which we replaced the N-terminal transmembrane region of CYP53A15 with a portion of the N-terminus of various mammalian P450s. PHBA productivity was the greatest when CYP53A15 expression was induced at $20^{\circ}C$ in $2{\times}YT$ medium in host E. coli strain ${\Delta}gcvR$ transformed with an N-terminal transmembrane region of rabbit CYP2C3. By optimizing each reaction condition (reaction temperature, substrate concentration, reaction time, and E. coli cell concentration), we achieved 90% whole-cell conversion of benzoate. Our data demonstrate that the described novel E. coli bioconversion system is a more efficient tool for PHBA production from benzoate than the previously described yeast system.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.413-417
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• 2015

Recently, we isolated HY253, a novel decahydrofluorene analog with a molecular structure of 7,8a-divinyl-2,4a,4b,5,6,7,8,8a,9,9a-decahydro-1H-fluorene-2,4a,4b,9a-tetraol from the roots of Aralia continentalis, which is known as Dokwhal (獨活), a traditional medicinal herb. Moreover, we previously reported its cytotoxic activity on cancer cell proliferation in human lung cancer A549 and cervical cancer HeLa cells. The current study aimed to evaluate its detailed molecular mechanisms in cell cycle arrest and apoptotic induction in human hepatocellular carcinoma HepG2 cells. Flow cytometric analysis of HepG2 cells treated with $60{\mu}M$ HY253 revealed appreciable cell cycle arrest at the G1 phase via inhibition of Rb phosphorylation and down-regulation of cyclin D1. Furthermore, using western blots, we found that up-regulation of cyclin-dependent kinase inhibitors, such as p21^CIP1 and p27^KIP1, was associated with this G₁ phase arrest. Moreover, TUNEL assay and immunoblottings revealed apoptotic induction in HepG2 cells treated with $60{\mu}M$ HY253 for 24 h, which is associated with cytochrome c release from mitochondria, via down-regulation of anti-apoptotic Bcl-2 protein, which in turn resulted in activation of caspase-9 and -3, and proteolytic cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, we suggest that HY253 may be a potent chemotherapeutic hit compound for treating human liver cancer cells via up-regulation and activation of the p53 gene.

• Journal of Periodontal and Implant Science
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• v.34 no.4
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• pp.807-818
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• 2004

산화질소는 생리적 농도에서 세포내 신호전달자로 작용하지만 높은 농도에서는 세포독성을 일으킨다. 최근 치은 섬유아세포와 치주인대 섬유아세포는 산화질소 합성효소를 가지고 있고 세균의 lipopolysaccharide나 cytokine에 의해 대량의 높은 농도의 산화질소가 합성된다는 보고가 있음에도 지금까지 치은 조직에서 산화질소의 세포독성에 대한 연구는 아직 이루어 지지않고 있다. 본 연구는 사람의 치은 섬유아세포에서, 산화질소유도세포 고사기전을 밝히는데 목적이 있다. 세포 생장력은 MTT 방법으로 측정하였고, 세포의 형태적 변화는 Diff-Quick 염색법으로 조사하였다. Bcl-2 famly와 Fas 발현 정도는 RT-PCR 방법에 의해 확인하였으며, caspase-3, -8 와 -9의 활성은 spectrophotometer로 reactive oxygen species (ROS)는 형광분광계에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 western blot으로 조사하였다. 산화질소 유리제인 sodium nitroprusside (SNP) 처리는 사람 섬유아세포의 생존률을 시간과 농도 의존적으로 감소시켰고, 세포용적축소, 염색사 용축, DNA 절편화를 일으켰다. 또한, SNP 처리로 미토콘드리아에서 세포질로 유리되는 cytochrome c 양이 증가되었고, caspase-9 과 caspase-3 의 활성이 증가되었다. 한편, SNP 처리에 의해 death receptor 구성요소인 Fas 발현이 증가되었고, caspase-8의 활성이 증가되었다. Bcl-2 family 에 대한 RT-PCR 분석결과, 세포고사를 억제하는 Bcl-2 발현은 감소되었으나 세포고사를 자극하는 Bax와 Bid의 발현은 증가되었다. Soluble guanylate cyclase 억제제인 ODQ는 SNP에 의한 세포 생존율 감소를 차단하지 못했다. 따라서, 본 실험의 결과들은 사람 섬유아세포에서 산화질소유도 세포고사에 Bcl-2 family나 ROS가 매개하는 미토콘드리아 의존 및 death receptor 의존 세포고사기전이 관여함을 시사하였다.

• BMB Reports
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• v.46 no.1
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• pp.47-52
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• 2013

Intestinal epithelial cell (IEC) apoptosis induced by hypoxia compromise intestinal epithelium barrier function. Both Akt and Hsp90 have cytoprotective function. However, the specific role of Akt and $Hsp90{\beta}$ in IEC apoptosis induced by hypoxia has not been explored. We confirmed that hypoxia-induced apoptosis was reduced by $Hsp90{\beta}$ overexpression but enhanced by decreasing $Hsp90{\beta}$ expression. $Hsp90{\beta}$ overexpression enhanced BAD phosphorylation and thus reduced mitochondrial release of cytochrome C. Reducing $Hsp90{\beta}$ expression had opposite effects. The protective effect of $Hsp90{\beta}$ against apoptosis was negated by LY294002, an Akt inhibitor. Further study showed that Akt phosphorylation was enhanced by $Hsp90{\beta}$, which was not due to the activation of upstream PI3K and PDK1 but because of stabilization of pAkt via direct interaction between $Hsp90{\beta}$ and pAkt. These results demonstrate that $Hsp90{\beta}$ may play a significant role in protecting IECs from hypoxia-induced apoptosis via stabilizing pAkt to phosphorylate BAD and reduce cytochrome C release.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.244-251
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• 2017

A total of 15 larvae [3.53~19.49 mm standard length (SL)] belonging to the family Bothidae collected from the southern sea of Korea in 2016 were identified as Psettina tosana based on 434 base-pair sequences of mitochondrial DNA cytochrome c oxidase subunit I. Larvae of Psettina tosana have anterior-most two elongated dorsal fin rays. Uniserial melanophores present on the dorsal and anal fin base, whereas melanophores on the body absent. An inflection point in the relative growth of head length and head depth against SL was shown between 9.93 mm and 10.73 mm SL. The examined larvae of Psettina tosana are clearly distinguished from the most similar species, Psettina iijimae in having no melanophore patches in the proximity of dorsal and anal fin base.

• Research in Plant Disease
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• v.26 no.1
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• pp.53-56
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• 2020

Red spots symptoms were observed on the leaves of Rumex japonicus Houtt. in Goesan, Korea, in May 2019. Diseased leaf showing red spot and white-colored sori were found behind of diseased leaves. Aeciospores were confirmed and observed using a stereomicroscope, light microscope, and scanning electron microscope. They were globose or ovoid and measured 19.0-24.4×19.0-24.5 ㎛, with verrucae ornamentation. For the phylogenetic analysis, partial of large subunit rDNA region and cytochrome c oxidase subunit III were sequenced. As a result, the isolated fungus species showed high similarities with Puccinia prizeliana. Based on the previous report, morphological characters, phylogenetic analysis, it was confirmed as Puccinia phragmitis which have not been reported in Korea, and we firstly report this fungal agent on R. japonicus as P. phragmitis in Korea.

• Journal of Nutrition and Health
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• v.34 no.3
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• pp.299-305
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• 2001

The purpose of this study was to investigate the effects of catechin on the changes of microsomal mixed function oxidase(MFO) system and oxidative damage in rat liver exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to one normal and microwave exposed groups: microwave exposed groups were divided three groups: catechin free diet(MW) group, 0.25% catechin(MW+0.25C) group and 0.5% catechin(MW+0.5C) group to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency 2.45GHz for 15 min and then the changes pattern of mixed function oxidase system and oxidative damage were investigated for 16 days. The activity of XOD in MW group was increased from 4 day to 8 days after irradiation, compared to normal group and decreased to the level of normal group 16 days. But catechin supplementation group were maintained to the normal level. The contents of cytochrome P(sub)450 and NADPH cytochrome P(sub)450 reductase activities in liver of MW group was increased from 4 day to 8 day after irradiation, compared to normal group and decreased to the level of normal group at 16 day. But catechin supplementation group were recovered to the normal level. The contents of superoxide radical in liver of MW group was increased 1.28, 1.25, 1.17 fold of normal group at 4,6 and 8 days days after irradiation. respectively, but catechin supplementation group were maintained the normal level. The contents of lipifuscin in liver have a same tendency in superoxide radical contents. These result suggested that the supplementation of catechin have control the mixed function oxidase system and oxidative damage and that may help to recover tissues from microwave damage. (Korean J Nutrition 34(3) : 299~305, 2001)

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.51-58
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• 2006

The promoting effect of hydrogen peroxide ($H_2O_2$) against the cytotoxicity of 1-methyl-4-phenylpyridinium ($MPP^+$) in differentiated PC12 cells was assessed by measuring the effect on the mitochondrial membrane permeability. Treatment of PC12 cells with $MPP^+$ resulted in the nuclear damage, decrease in the mitochondrial transmembrane potential, cytosolic accumulation of cytochrome c, activation of caspase-3, increase in the formation of reactive oxygen species (ROS) and depletion of GSH. Addition of $H_2O_2$ enhanced the $MPP^+-induced$ nuclear damage and cell death. Catalase, Carboxy-PTIO, Mn-TBAP, N-acetylcysteine, cyclosporin A and trifluoperazine inhibited the cytotoxic effect of $MPP^+$ in the presence of $H_2O_2$. Addition of $H_2O_2$ promoted the change in the mitochondrial membrane permeability, ROS formation and decrease in GSH contents due to $MPP^+$ in PC12 cells. The results show that the $H_2O_2$ treatment promotes the cytotoxicity of $MPP^+$ against PC12 cells. $H_2O_2$ may enhance the $MPP^+$-induced viability loss in PC12 cells by promoting the mitochondrial membrane permeability change, release of cytochrome c and subsequent activation of caspase-3, which is associated with the increased formation of ROS and depletion of GSH. The findings suggest that $H_2O_2$ as a promoting agent for the formation of mitochondrial permeability transition may enhance the neuronal cell injury caused by neurotoxins.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.1062-1067
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• 2005

The purpose of this study was to examine the inhibition effect of Zizania latifolia that has been used heart disease, Diabetes Mellitus and Skin disease for a long time on apoptosis induced by $H_2O_2$ in Neuro2A cell. Neuro2A cells were cultivated in RPMI(GibcoBRL) with $5\%$, FBS and treated with $H_2O_2$, and Zizania latifolia. We measured the cell viability and analyzed DNA fragmentation. Activity of PARP, Cytochrome C, caspase-9, caspase-3, p53, p21, Bax and Bcl-2 in the cell was examined by using western blot. The cell viability in Zizania latifolia treatment (60ug/ml<) decreased significantly compared with that of none treatment. (p<0.001) Zizania latifolia increased cell viability about twice as much as that being injury by $H_2O_2$. (Zizania Latifolia 20ug/ml, $H_2O_2$ 200uM, P<0.001) DNA fragmentation developed by $H_2O_2$, but was not developed in Zizania latifolia treatment. PARP, Cytochrome C, caspase-9 and caspase-3 activated all by $H_2O_2$ but were not activated in Zizania latifolia treatment.. P53, P2l and Bu activated by $H_2O_2$, and Bcl-2 got into inactivation. But the opposite results appeared in Zizania latifolia treatment. In conclusion, these results suggest that Zizania latifolia inhibit the development of DNA fragmentation and apoptosis by $H_2O_2$ and the antioxidant action of Zizania latifolia is effective. More researches about effect of Zizania latifolia are considered to need.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.531-536
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• 2007

The aerial part of Artemisia iwayomogi Kitamura has traditionally been used for inflammation, infectious disease, cancer, pyretic, diuretic, liver protective effect, and choleretic purposes in Korea. We investigated that the essential oil induces apoptosis in KB cell as evidenced by Hoechst-33258 dye staining, flow cytometry (cell cycles), and DNA fragmentation for nuclear condensation and Western blotting for activation of caspases-3, -8, -9, Bax, Bcl-2, cytochrome c, and poly (ADP-ribose) polymerase (PARP) cleavage. In the present study, we found that the essential oil could induce apoptosis in KB cells, as characterized by DNA fragmentation, activation of caspase-3, -8, and -9, and PARP cleavage. The efficacious induction of apoptosis was observed as a dose-dependent. The essential oil-induced apoptotic cell death was accompanied by up-regulation of Bax and down-regulation of Bcl-2. The essential oil also caused the loss of mitochondrial membrane potential and cytochrome c release from mitochondria to cytosol. These findings indicate that mitochondrial pathways might be involved in the essential oil-induced apoptosis and enhance our understanding of the anticancer function of the essential oil in herbal medicine.