• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.54-54
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• 1992

약물, hormone, 독성물질등의 대사능과 발암 가능성등이 간장 장해시 및 ketosis시에 달라지는 원인과 기전, 독성물질 대사효소의 변동과 그 작용기전을 규명하고자, 대표적인 간장장해 물질인 carbon tetrachloride를 rat에 투여하여 간장 장해를 일으키고, 당뇨병, starvation, high-fat diet처리하여 ketosls상태를 만든 후에, specific cytochrome P45O polyclonal antibodies와 cDNA probes를 사용하여, enzyme activitieg, Western immunoblot analysis와 mRNA Northern blot analysis 등을 실험하여, 간장 장해와 ketosis시 cytochrome P45O의 변동과 그 작용기전, regulation을 규명하고자 하였다. 실험 결과, $CCl_4$투여후 P450IIE enzyme (aniline hydroxylase) 활성이 시간 의존적으로 급격히 떨어졌고, P450IIE protein양이 똑같은 방식으로 감소되었으나 mRNA level은 변화가 없었다. $CCl_4$에 의해서 P450IIE는 protein의 특이적인 파괴에 의한 post-translational reduction됨을 알 수 있었다. 반면에 당뇨병, starvation, high-fat diet등 ketosis시에는 P450IIE 효소활성이 2-3배 증가되었고, P450IIE protein양도 같은 수준으로 증가되었으며, mRNA도 증가 되었다. Ketosis시에는 P450IIE가 pretranslational activation됨을 알 수 있었다.

• Journal of Life Science
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• v.19 no.3
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• pp.305-310
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• 2009

Plasmid pGKV21 contains a 229-nucleotide (nt) single-strand DNA initiation (ssi) signal. Using asymmetric PCR, we prepared a small single-stranded (ss) DNA fragment of the ssi signal and, using the 229-nt ssDNA fragment, determined the requirements of RNA polymerase for priming and DNA-protein interaction. The ssi fragment prepared was able to generate primer RNAs with almost the same efficiency as the $M13{\Delta}lac182/229$ phage DNA. However, the cssi (complementary strand of the ssi signal) fragment could not synthesize primer RNAs. This result suggests that the 229-nt ssi signal functions in a strand specific manner. Gel retardation and DNase I footprinting demonstrated that the synthesized ssi fragment could interact with both E. coli RNA polymerase and SSB protein to synthesize primer RNA. In Escherichia coli [pWVAp], an addition of rifampicin resulted in an accumulation of ssDNA, indicating that the host-encoded RNA polymerase is involved in the conversion of ssDNA to double-stranded plasmid DNA.

• Archives of Pharmacal Research
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• v.22 no.3
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• pp.243-248
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• 1999

Sialic acids are key determinants for biological processes, such as cell-cell interaction and differentiation. Sialyltransferases contribute to the diversity in carbohydrate structure through their attachment of sialic acid in various terminal positions on glycolipid and glycoprotein (N-linked and O-linked) carbohydrate groups. Gal$\beta$ 1,3(4)GlcNAc $\alpha$2,3-sialyltransferase (ST3Gal III) is involved in the biosynthesis of $sLe^{X}$ and sLe^{a}$ known as selection ligands and tumor-associated carbohydrate structures. The appearance and differential distribution of ST3Gal III mRNA during mice embryogenesis [embryonic (E) days; E9, E11, E13, E15] were investigated by in situ hybridization with digoxigenin-labeled RNA probes coupled with alkaline phosphatase detection. On E9, all tissues were positive for ST3Gal III mRNA expression whereas ST3Gal III mRNA on E11 was not detected throughout all tissues. On E13, ST3GAl III mRNA was expressed in different manner in various tissues. In this stage, ST3Gal III mRNA was positive only in the liver, pancreas and bladder. On E15, specific signal for ST3GAl III was detected in the liver, lung and forebrain. These results indicate that ST3Gal III is differently expressed at developmental stages of mice embryo, and this may be importantly related with regulation of organogenesis in mice.

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.1070-1076
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• 2009

Telomerase reverse transcriptase (TERT), which prolongs the replicative life span of cells, is highly upregulated in 85-90% of human cancers, whereas most normal somatic tissues in humans express limited levels of the telomerase activity. Therefore, TERT has been a potential target for anticancer therapy. Recently, we described a new approach to human cancer gene therapy, which is based on the group I intron of Tetrahymena thermophila. This ribozyme can specifically mediate RNA replacement of human TERT (hTERT) transcript with a new transcript harboring anticancer activity through a trans-splicing reaction, resulting in selective regression of hTERT-positive cancer cells. However, to validate the therapeutic potential of the ribozyme in animal models, ribozymes targeting inherent transcripts of the animal should be developed. In this study, we developed a Tetrahymena-based trans-splicing ribozyme that can specifically target and replace the mouse TERT (mTERT) RNA. This ribozyme can trigger transgene activity not only also in mTERT-expressing cells but hTERT-positive cancer cells. Importantly, the ribozyme could selectively induce activity of the suicide gene, a herpes simplex virus thymidine kinase gene, in cancer cells expressing the TERT RNA and thereby specifically hamper the survival of these cells when treated with ganciclovir. The mTERT-targeting ribozyme will be useful for evaluation of the RNA replacement approach as a cancer gene therapeutic tool in the mouse model with syngeneic tumors.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.3
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• pp.346-353
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• 2015

Glucocorticoids (GCs) are steroid hormones regulated through responses to stress to maintain diverse metabolic and homeostatic functions. GCs act on the glucocorticoid receptor (GR), a member of the nuclear receptor family. This study identified and characterized the GR gene from the big-belly seahorse Hippocampus abdominalis designating it HaGR. The open reading frame of the HaGR cDNA was 2,346 bp in length, encoding a 782-amino-acid polypeptide with a theoretical isoelectric point of 6.26 and predicted molecular mass of 86.8 kDa. Nuclear receptors share a common structural organization, comprising an N-terminal transactivation domain, DNA-binding domain, and C-terminal ligand-binding domain. The tissue-specific mRNA expression profile of HaGR was analyzed in healthy seahorses using a qPCR technique. HaGR mRNA was expressed ubiquitously in all of the tissues examined, with the highest expression levels in kidney, intestine, stomach, and gill tissues. The mRNA expression in response to immune challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), Edwardsiella tarda, and Streptococcus iniae revealed that it is inducible in response to pathogen infection. These results suggest that HaGR is involved in the immune response of the big-belly seahorse.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.827-833
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• 1999

In this study, we have investigated the effect of Biphenyl Dimethyl Dicarboxylate (DDB), a synthetic analogue of Schizandrin C isolated from Schizandrae Fructus on cytochrome $P_450$ lAl and 2Bl, and the protective mechanism against $CCl_4-induced$ hepatotoxicity in rat liver. After DDB was administered into male rats for different periods of time (1~7 days) and with different doses (25, 50, 100 and 200 mg/kg), mRNA levels of CYPlAl were measured by polymearse chain reaction (PCR) and assayed the activities of CYPlAl specific ethoxyresorufin-O-dealkylase (EROD) and CYP2Bl specific benzyloxyresorufin-O-dealkylase (BROD). DDB treatment resulted in increase in CYP2Bl mRNA level and BROD activity, whereas there was no change in CYPlAl mRNA level and EROD activity. This effect of DDB was time-and dose-dependent and reached maximal level by 3 day and 200 mg/kg treatment. In addition, rats were pre-treated with DDB at doses of 25, 50 or 100 mg/kg daily for 4 days, 3-hr after final treatment on the 4th day, $CCl_4$ 0.3ml/kg was intraperitonially injected into the rats to examine the effect of DDB on $CCl_4-induced$ hepatic injury. Serum levels of ALT and AST were determined and histopathological examination was done in rat liver. Furthermore, we have measured hepatic microsomal malondialdehyde(MDA) level, a parameter of lipid peroxidation. Based on serum ALT level and lipid peroxidation, pretreatment of DDB, 50 mg/kg appeared the most protective effect against $CCl_4-induced$ heapatotoxity. These results indicate that DDB stimulates CYP2Bl mRNA level and BROD activity in time and dose dependent manner and suggest that protective effect of DDB on $CCl_4-induced$ hepatotoxicity may be mediated through free radical scavenging.

• IMMUNE NETWORK
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• v.11 no.1
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• pp.11-41
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• 2011

The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA.

• BMB Reports
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• v.50 no.4
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• pp.158-159
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• 2017

MicroRNAs (miRNAs) regulate gene expression by guiding the Argonaute (Ago)-containing RNA-induced silencing complex (RISC) to specific target mRNA molecules. It is well established that miRNAs are stabilized by Ago proteins, but the molecular features that trigger miRNA destabilization from Ago proteins remain largely unknown. To explore the molecular mechanisms of how targets affect the stability of miRNAs in human Ago (hAgo) proteins, we employed an in vitro system that consisted of a minimal hAgo2-RISC in HEK293T cell lysates. Surprisingly, we found that miRNAs are drastically destabilized by binding to seedless, non-canonical targets. We showed that miRNAs are destabilized at their 3' ends during this process, which is largely attributed to the conformational flexibility of the L1-PAZ domain. Based on these results, we propose that non-canonical targets may play an important regulatory role in controlling the stability of miRNAs, instead of being regulated by miRNAs.

• BMB Reports
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• v.33 no.5
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• pp.359-365
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• 2000

Ribozymes are catalytic RNAs that can cleave RNAs at specific sites, thus they have been employed to degrade a target mRNA in vivo. Development of allosterically controllable ribozymes is of great current interest, but it remained difficult to furnish such functions to ribozymes in cultured cells or in animals. Recently, we designed allosterically controllable ribozymes termed maxizymes, which have sensor arms that recognize target mRNA sequences and, in the presence of such target sequences only, they form a cavity that can capture catalytically indispensable $Mg^{2+}$ ions, cleaving the target. The maxizyme was applied to therapy for chronic myelogenous leukemia (CML). It cleaved specifically the chimeric BCR-ABL mRNA, which caused CML, without damaging the normal ABL or BCR mRNA in mammalian cells and also in mice, providing the first successful example for allosteric control of the activity of artificial ribozymes in vivo.

• BMB Reports
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• v.42 no.6
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• pp.367-372
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• 2009

In this study, we showed that WAX9D, a nonspecific lipid-transfer protein found in broccoli, binds palmitate (C16) and stearate (C18) with dissociation constants of 0.56 ${\mu}M$ and 0.52 ${\mu}M$, respectively. WAX9D was fused to thioredoxin protein by genetic manipulation to enhance its solubility. The data revealed strong interaction of Trx-WAX9D with palmitate and stearate. The dissociation constants of Trx-WAX9D for palmitate and stearate were 1.1 ${\mu}M$ and 6.4 ${\mu}M$, respectively. The calculated number of binding sites for palmitate and stearate was 2.5 to 2.7, indicating that Trx-WAX9D can bind three molecules of fatty acids. Additionally, Trx-WAX9D was shown to inhibit the apoptotic effect of palmitate in endothelial cells. Our data using Trx-WAX9D provide insight into the broad spectrum of its biological applications with specific palmitate binding.