• 생명과학회지
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• 제22권8호
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• pp.999-1008
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• 2012

자기 현가적(self-sustaining) 조절 장치인 생체시계는 24시간 주기의 생체리듬을 조절하며 또한 생물체로 하여금 매일 변화하는 자연환경의 외부 신호를 인지할 수 있도록 해준다. 생체시계 유전자의 발현 조절은 전사/해독의 역환류 기작을 통해 이루어진다. 애기장대 LATE ELONGATED HYPOCOTYL (LHY)와 CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1)는 아침에 최고조로 발현되며 해독된 LHY and CCA1는 저녁에 최고로 발현되는 TIMING OF CAB EXPRESSION1 (TOC1)의 발현을 억제한다. TOC1단백질은 LHY와 CCA1 발현을 촉진시킴으로써 생체시계의 핵심 진자(oscillator)를 형성한다. 동물에서 생체시계의 주요 전사 인자인CLOCK은 아세틸화효소 활성 기능을 가지며, 이는 생체시계의 기능 유지에 아세틸화의 중요함을 의미한다. 하지만 애기장대 생체시계에 아세틸화를 담당하는 인자에 대한 정보는 현재 보고된 바가 없다. 본 연구에서 DET1 (De-Etiolated1)는 암조건하에서 애기장대 생체시계 관련 핵심인자 중 하나인 LHY발현을 억제하는데 필요하며 이의 억제는 H3Ac 조절을 통해 이루어짐을 증명하였다. 하지만 LHY 아세틸화를 담당하는 효소의 발굴 및 이들 효소와 DET1과의 연결을 찾는 문제는 여전히 미재로 남아있다.

• 동의생리병리학회지
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• 제21권4호
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• pp.973-981
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• 2007

In the present study, we investigated the antiproliferative activity of the water extract of Samgibopae-tang (SGBPT) in NCI-H460 and A549 non-small-cell lung cancer cell lines. We found that exposure of A549 cells to SGBPT resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay, however SGBPT did not affect the growth of NCI-H460 cells. The antiproliferative effect by SGBPT treatment in A549 cells was associated with morphological changes such as membrane shrinking and cell rounding up. SGBPT treatment did not induce the cell cycle arrest in both cell lines, however the frequency of sub-G1 population was concentration-dependently increased by SGBPT treatment in A549 cells. SGBPT treatment partially induced the expression of tumor suppressor p53 in A549 cells and the expression of cyclin-dependent kinase inhibitor p21(WAF1/CIP1) was markedly increased in both transcriptional and translational levels in A549 cells. The up-regulation of p21 by SGBPT occurred in a similar a concentration dependent manner to that observed with the inhibition of cell viability and induction of sub-G1 population of the cell cycle. However SGBPT treatment did not affect other growth regulation-related genes such as early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug-activated gene-1 (NAG-1), inducible nitric oxide synthease (iNOS), cyclooxygenases (COXs), telomere-regulatory factors in A549 as well as NCI-H460 cells. Taken together, these findings suggested that SGBPT-induced inhibition of human lung carcinoma A549 cell growth was aoosciated with the induction of p21 and the results provided important new insights into the possible molecular mechanisms of the anti-cancer activity of SGBPT.

• Journal of Biomedical and Translational Research
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• 제19권4호
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• pp.116-124
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• 2018

Korean Native Pig (KNP) has a uniform black coat color, excellent meat quality, white colored fat, solid fat structure and good marbling. However, its growth performance is low, while the western origin Yorkshire pig has high growth performance. To take advantage of the unique performance of the two pig breeds, we raised crossbreeds (KNP ${\times}$ Yorkshire to make use of the heterotic effect. We then analyzed the liver transcriptome as it plays an important role in fat metabolism. We sampled at two stages: 10 weeks and at 26 weeks. The stages were chosen to correspond to the change in feeding system. A total of 16 pigs (8 from each stage) were sampled and RNA sequencing was performed. The reads were mapped to the reference genome and differential expression analysis was performed with edgeR package. A total of 324 genes were found to be significantly differentially expressed (${\left|log2FC\right|}$ > 1 & q < 0.01), out of which 180 genes were up-regulated and 144 genes were down-regulated. Principal Component Analysis (PCA) showed that the samples clustered according to stages. Functional annotation of significant DEGs (differentially expressed genes) showed that GO terms such as DNA replication, cell division, protein phosphorylation, regulation of signal transduction by p53 class mediator, ribosome, focal adhesion, DNA helicase activity, protein kinase activity etc. were enriched. KEGG pathway analysis showed that the DEGs functioned in cell cycle, Ras signaling pathway, p53 signaling pathway, MAPK signaling pathway etc. Twenty-nine transcripts were also part of the DEGs, these were predominantly Cys2His2-like fold group (C2H2) family of zinc fingers. A protein-protein interaction (PPI) network analysis showed that there were three highly interconnected clusters, suggesting an enrichment of genes with similar biological function. This study presents the first report of liver tissue specific gene regulation in a cross-bred Korean pig.

• Journal of Ginseng Research
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• 제47권6호
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• pp.714-725
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• 2023

Background: Our previous investigation indicated that the preparation of Panax ginseng Meyer (P. ginseng) inhibited melanogenesis. It comprised salicylic acid (SA), protocatechuic acid (PA), p-coumaric acid (p-CA), vanillic acid (VA), and caffeic acid (CA). In this investigation, the regulatory effects of P. ginseng phenolic acid monomers on melanin production were assessed. Methods: In vitro and in vivo impact of phenolic acid monomers were assessed. Results: SA, PA, p-CA and VA inhibited tyrosinase (TYR) to reduce melanin production, whereas CA had the opposite effects. SA, PA, p-CA and VA significantly downregulated the melanocortin 1 receptor (MC1R), cycle AMP (cAMP), protein kinase A (PKA), cycle AMP-response element-binding protein (CREB), microphthalmia-associated transcription factor (MITF) pathway, reducing mRNA and protein levels of TYR, tyrosinase-related protein 1 (TYRP1), and TYRP2. Moreover, CA treatment enhanced the cAMP, PKA, and CREB pathways to promote MITF mRNA level and phosphorylation. It also alleviated MITF protein level in α-MSH-stimulated B16F10 cells, comparable to untreated B16F10, increasing the expression of phosphorylation glycogen synthase kinase 3β (p-GSK3β), β-catenin, p-ERK/ERK, and p-p38/p38. Furthermore, the GSK3β inhibitor promoted p-GSK3β and p-MITF expression, as observed in CA-treated cells. Moreover, p38 and ERK inhibitors inhibited CA-stimulated p-p38/p38, p-ERK/ERK, and p-MITF increase, which had negative binding energies with MC1R, as depicted by molecular docking. Conclusion: P. ginseng roots' phenolic acid monomers can safely inhibit melanin production by bidirectionally regulating melanin synthase transcription. Furthermore, they reduced MITF expression via MC1R/cAMP/PKA signaling pathway and enhanced MITF post-translational modification via Wnt/mitogen-activated protein kinase signaling pathway.

• Toxicological Research
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• 제8권2호
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• pp.343-357
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• 1992

Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.194-194
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• 2017

Camelina (Camelina sativa L.) is a potential bio-energy crop that has short life cycle about 90 days and contains high amount of unsaturated fatty acid which is adequate to bio-diesel production. Enhancing environmental stress tolerance is a main issue to increase not only crop productivity but also big mass production. CsRCI2s (Rare Cold Inducible 2) are cold and salt stress related protein that localized at plasma membrane (PM) and assume to be membrane potential regulation factor. These proteins can be divide into C-terminal tail (CsRCI2D/E/F/G) or no-tail group (CsRCI2A/B/C/H). However, function of CsRCI2s are less understood. In this study, physiological responses and functional characterization of CsRCI2s of Camelina under salt stress were analyzed. Full-length CsRCI2s (A/B/E/F) and CsPIP2;1 sequences were confirmed from Camelina genome browser. Physiological investigations were carried out using one- or four-week-old Camelina under NaCl stress with dose and time dependent manner. Transcriptional changes of CsRCI2A/B/E/F and CsPIP2;1 were determined using qRT-PCR in one-week-old Camelina seedlings treated with NaCl. Translational changes of CsRCI2E and CsPIP2;1 were confirmed with western-blot using the antibodies. Water transport activity and membrane potential measurement were observed by cRNA injected Xenopus laevis oocyte. As results, root growth rate and physiological parameters such as stomatal conductance, chlorophyll fluorescence, and electrolyte leakage showed significant inhibition in 100 and 150 mM NaCl. Transcriptional level of CsPIP2;1 did not changed but CsRCI2s were significantly increased by NaCl concentration, however, no-tail type CsRCI2A and CsRCI2B increased earlier than tail type CsRCI2E and CsRCI2F. Translational changes of CsPIP2;1 was constitutively maintained under NaCl stress. But, accumulation of CsRCI2E significantly increased by NaCl stress. CsPIP2;1 and CsRCI2A/B/E/F co-expressed Xenopus laevis oocyte showed decreased water transport activity as 61.84, 60.30, 62.91 and 76.51 % at CsRCI2A, CsRCI2B, CsRCI2E and CsRCI2F co-expression when compare with single expression of CsPIP2;1, respectively. Moreover, oocyte membrane potential was significantly hyperpolarized by co-expression of CsRCI2s. However, higher hyperpolarized level was observed in tail-type CsRCI2E and CsRCI2F than others, especially, CsRCI2E showed highest level. It means transport of $Na^+$ ion into cell is negatively regulated by expression of CsRCI2s, and, function of C-terminal tail is might be related with $Na^+$ ion influx. In conclusion, accumulation of NaCl-induced CsRCI2 proteins are related with $Na^+$ ion exclusion and prevent water loss by CsPIP2;1 under NaCl stress.

• 생명과학회지
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• 제21권10호
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• pp.1494-1499
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• 2011

${\beta}$-lapachone은 남미에 자생하는 lapacho 나무(Tabeuia avellanedae)의 수액에 함유된 quinone계열의 일종으로 많은 인체암세포에서 apoptosis를 유발하는 것으로 알려져 있다. 본 연구는 A549 인체폐암세포를 대상으로 ${\beta}$-lapachone에 의한 apoptosis 유발 과정에서 나타나는 또 다른 현상들을 조사하기 위하여 실시되었다. ${\beta}$-lapachone이 처리된 A549 세포는 처리 농도의 증가에 따라 생존율이 감소되었으며, 이는 apoptosis 유발과 연관이 있음을 MTT assay와 flow cytometry 분석을 통하여 확인하였다. ${\beta}$-lapachone에 의한 A549 세포의 증식억제는 종양억제유전자 p53과 cyclin-dependent kinase 저해제인 p21의 발현을 전사 및 번역 수준에서 증가시켰으며, p53 단백질의 인산화 증가와 연관성이 있었다. 또한 ${\beta}$-lapachone은 caspase-3과 -9를 활성화시켰으며, 활성화된 caspase-3의 기질 단백질들[poly(ADP-ribose) polymerase, ${\beta}$-catenin 및 phospholipase C-$\gamma$1]의 단편화를 유도하였다. 아울러 ${\beta}$-lapachone은 cyclooxygenase (COX)-2의 mRNA 및 단백질의 발현을 억제하였으나 COX-1의 발현에는 영향을 미치지 않았으며, ${\beta}$-lapachone에 의한 COX-2의 발현억제는 prostaglandin E2의 생성 저하에 관련이 있었다. 본 연구의 결과는 ${\beta}$-lapachone의 항암활성 기전의 이해와 더불어 ${\beta}$-lapachone이 폐암세포에서 강력한 항암활성이 있음을 보여 주는 것이다.

• Molecules and Cells
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• 제43권10호
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• pp.870-879
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• 2020

Dendrites require precise and timely delivery of protein substrates to distal areas to ensure the correct morphology and function of neurons. Many of these protein substrates are supplied in the form of ribonucleoprotein (RNP) complex consisting of RNA-binding proteins (RBPs) and mRNAs, which are subsequently translated in distal dendritic areas. It remains elusive, however, whether key RBPs supply mRNA according to local demands individually or in a coordinated manner. In this study, we investigated how Drosophila sensory neurons respond to the dysregulation of a disease-associated RBP, Ataxin-2 (ATX2), which leads to dendritic defects. We found that ATX2 plays a crucial role in spacing dendritic branches for the optimal dendritic receptive fields in Drosophila class IV dendritic arborization (C4da) neurons, where both expression level and subcellular location of ATX2 contribute significantly to this effect. We showed that translational upregulation through the expression of eukaryotic translation initiation factor 4E (eIF4E) further enhanced the ATX2-induced dendritic phenotypes. Additionally, we found that the expression level of another disease-associated RBP, fragile X mental retardation protein (FMRP), decreased in both cell bodies and dendrites when neurons were faced with aberrant upregulation of ATX2. Finally, we revealed that the PAM2 motif of ATX2, which mediates its interaction with poly(A)-binding protein (PABP), is potentially necessary for the decrease of FMRP in certain neuronal stress conditions. Collectively, our data suggest that dysregulation of RBPs triggers a compensatory regulation of other functionally-overlapping RBPs to minimize RBP dysregulation-associated aberrations that hinder neuronal homeostasis in dendrites.

• 대한의생명과학회지
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• 제12권2호
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• pp.81-89
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• 2006

The ischemia-responsive 94 gene (irp94) encoding a 94 kDa endoplasmic reticulum resident protein was investigated its molecular properties associated with unfoled protein responses. First, the expression of irp94 mRNA was tested after the reperfusion of the transient forebrain ischemia induction at the central nervous system in three Mongolian gerbils. Second, irp94 expression in PC12 cells, which are derived from transplantable rat pheochromocytoma cultured in the DMEM media, was tested at transcriptional and translational levels. The half life of irp94 mRNA was also determined In PC12 cells. Last, the changes of irp94 mRNA expression were investigated by the addition of various ER stress inducible chemicals (A23187, BFA, tunicamycin, DTT and $H_2O_2$) and proteasome inhibitors, and heat shock. High level expression of irp94 mRNA was detected after 3 hours reperfusion in the both sites of the cerebral cortex and hippocampus of the gerbil brain. The main regulation of irp94 mRNA expression in PC 12 cells was determined at the transcriptional level. The half life of irp94 mRNA in PC12 cells was approximately 5 hours after the initial translation. The remarkable expression of irp94 mRNA was detected by the treatment of tunicamycin, which blocks glycosylation of newly synthesized polypeptides, and $H_2O_2$, which induces apoptosis. When PC12 cells were treated with the cytosol proteasome inhibitors such as ALLN (N-acetyl-leucyl-norleucinal) and MG 132 (methylguanidine), irp94 mRNA expression was increased. These results indicate that expression of irp94 was induced by ER stress including oxidation condition and glycosylation blocking in proteins. Expression of irp94 was increased when the cells were chased after heat shock, suggesting that irp94 may be involved in recovery rather than protection against ER stresses. In addition, irp94 expression was remarkably increased when cytosol proteasomes were inhibited by ALLN and MG 132, suggesting that irp94 plays an important role for maintaining the ERAD (endoplasmic reticulum associated degradation) function.

• 한국식품위생안전성학회지
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• 제31권2호
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• pp.67-73
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• 2016

본 총설에서는 비-플라보노이드 폴리페놀인 레스베라트롤이 간, 골격근 및 지방조직에서 지질대사에 관계된 다양한 신호전달체계를 조절하여 지질 대사 효과를 유발시키는 과정에 관해 고찰하였다. 구체적으로 in vitro 연구에서 레스베라트롤은 지방생성을 줄여주고 apoptosis를 증가시켜 지방세포의 발달과정에 기인하며, 지방세포의 분화에 있어 중요한 전사인자인 $C/EBP{\beta}$, $C/EBP{\alpha}$, SREBP1c 및 $PPAR{\gamma}$의 활성을 감소시켜 항 비만 효과를 유발하는 효과가 있다는 것이 많은 논문들을 통해 증명되었다(Fig. 2). 또한, in vivo 연구에서 레스베라트롤은 지방 축적 과정을 억제하고 지질 분해 및 산화 경로를 자극하여 체지방 증가율을 감소시킨다는 것이 증명되었다. 최근 다양한 연구의 결과물(Table 2)들은 레스베라트롤이 지방생성, 지방분해, 열발생 및 지방산 산화에 관여하며 또한, 백색 지방을 갈색 지방으로 변화시키는 능력이 있다는 것을 증명하였다. 흥미롭게도 레스베라트롤은 비만뿐만이 아닌 심장발작 및 뇌졸중과 같은 다양한 대사질환을 예방하는데 도움이 되고, 결장암 및 간암 세포의 성장을 억제하는 효능이 있다는 사실이 밝혀지기도 하였다. 하지만 인간에 대한 레스베라트롤의 명확한 메커니즘을 알지 못하고 인간에게 나타나는 부작용에 관한 연구가 없기 때문에, 안전성을 확보하기 위해서는 다양한 실험모델을 이용한 레스베라트롤의 단기간 및 장기간에 대한 깊은 연구가 요구된다.