• BMB Reports
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• v.48 no.8
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• pp.467-472
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• 2015

Heat shock increases skin temperature during sun exposure and some evidence indicates that it may be involved in skin aging. The antioxidant response mediated by the transcription factor NF-E2-related factor 2 (Nrf2) is a critically important cellular defense mechanism that serves to limit skin aging. We investigated the effects of heat shock on collagenase expression when the antioxidant defense system was downregulated by knockdown of Nrf2. GSH and collagenases were analyzed, and the expression of inducible Nrf2, HO-1, and NQO1 was measured. HS68 cells were transfected with small interfering RNA against Nrf2. Heat shock induced the downregulation of Nrf2 in both the cytosol and nucleus and reduced the expression of HO-1, GSH, and NQO1. In addition, heat-exposed Nrf2-knockdown cells showed significantly increased levels of collagenase protein and decreased levels of procollagen. Our data suggest that Nrf2 plays an important role in protection against heat shock-induced collagen breakdown in skin. [BMB Reports 2015; 48(8): 467-472]

• BMB Reports
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• v.28 no.1
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• pp.51-56
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• 1995

Thioredoxin is a small redox protein with an active-site disulfide/dithiol, and is ubiquitous in bacteria, plants, and animals. To investigate the structure-function relationship of thioredoxin, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3(N to C-terminal) and C3-E. The hybrid thioredoxin genes were put under the T7 promoter and their productions were confirmed. The two hybrid thioredoxins complemented phenotypes of a thioredoxin-deficient E. coli strain. A strain containing the C3-E hybrid thioredoxin supported growth of the T7 phage, whereas a strain expressing the E-C3 hybrid thioredoxin did not. However, both hybrids supported growth of M13 phages. The two hybrid thioredoxins were also characterized in other aspects. Differences in activity between the hybrid thioredoxins were attributed to altered interactions of the N- and C-terminal domains of the molecule, which produced changes in the three-dimensional structure of the active site region.

• BMB Reports
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• v.49 no.7
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• pp.355-356
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• 2016

The THO/TREX complex consists of several conserved subunits and is required for mRNA export. In metazoans, THO/TREX binds a subset of mRNAs during RNA splicing, and facilitates their nuclear export. How THO/TREX selects RNA targets is, however, incompletely understood. In our recent study, we reported that THO is loaded onto Piwi-interacting RNA (piRNA) precursor transcripts independent of splicing, and facilitates convergent transcription in Drosophila ovary. The precursors are later processed into mature piRNAs, small noncoding RNAs that silence transposable elements (TEs). We observed that piRNAs originating from dual-strand clusters, where precursors are transcribed from both strands, were specifically affected by THO mutation. Analysis of THO-bound RNAs showed enrichment of dual-strand cluster transcripts. Interestingly, THO loading onto piRNA precursors was dependent on Cutoff (Cuff), which comprises the Rhino-Deadlock-Cutoff (RDC) complex that is recruited to dual-strand clusters by recognizing H3K9me3 and licenses convergent transcription from he cluster. We also found that THO mutation affected transcription from dual-strand clusters. Therefore, we concluded that THO/TREX is recruited to dual-strand piRNA clusters, independent of splicing events, via multi-protein interactions with chromatin structure. Then, it facilitates transcription likely by suppressing premature termination to ensure adequate expression of piRNA precursors.

• BMB Reports
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• v.50 no.9
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• pp.454-459
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• 2017

Tumor suppressor candidate 2 (Tusc2, also known as Fus1) regulates calcium signaling, and $Ca^{2+}$-dependent nuclear factor of activated T-cells (NFAT) and nuclear factor kappa B ($NF-{\kappa}B$) pathways, which play roles in osteoclast differentiation. However, the role of Tusc2 in osteoclasts remains unknown. Here, we report that Tusc2 positively regulates the differentiation of osteoclasts. Overexpression of Tusc2 in osteoclast precursor cells enhanced receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. In contrast, small interfering RNA-mediated knockdown of Tusc2 strongly inhibited osteoclast differentiation. In addition, Tusc2 induced the activation of RANKL-mediated $NF-{\kappa}B$ and calcium/calmodulin-dependent kinase IV (CaMKIV)/cAMP-response element (CRE)-binding protein CREB signaling cascades. Taken together, these results suggest that Tusc2 acts as a positive regulator of RANKL-mediated osteoclast differentiation.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.45-52
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• 2009

In order to understand the molecular interactions that occur between rice and the rice blast fungus during infection, we previously identified a number of rice blast fungal elicitor-responsive genes from rice (Oryza sativa cv. Milyang 117). Here, we report the cloning and characterization of the rice fungal elicitor-inducible gene Oshin1 (GenBank Accession Number AF039532). Sequence analysis revealed that the Oshin1 cDNA is 1067 bp long and contains an open reading frame encoding 205 amino acid residues. The Oshin1 gene shows considerable sequence similarity to the tobacco hin1 and hin2 genes. The predicted Oshin1 protein has a cysteine-rich domain at the N-terminus and is rich in leucine, serine, and alanine residues. Southern blot analysis suggests that Oshin1 gene is a member of a small gene family in the rice genome. To examine the expression of Oshin1, Northern blot analysis was conducted. Expression of the Oshin1 transcript is rapidly induced in suspension-cultured rice cells treated with fungal elicitor, salicylic acid or hydrogen peroxide. In addition, Oshin1 transcript levels are rapidly increased by treatment with $Ca^{2+}$/A23187. The expression of Oshin1 was also elevated in 3-week old leaf tissues upon ethephon application or fungal elicitor treatment. Our results suggest that the Oshin1 gene is involved in plant defense responses to environmental stresses.

• Journal of Life Science
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• v.6 no.4
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• pp.278-285
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• 1996

This experiments was conducted to determine the effect of dietary fiber(DF) levels with diets of isocaloric (3,010 kcal/1kg diet) and isoprotein(21% of diet) on colored brolier chicks(Juk jun hatchery farm). Four groups of 6 chicks 4 replication. were fed corn-soy meal diets containing 0% (DF, 5%), 2%(DF, 6%), 4%(DF, 7%), and 6%(DF, 8%) of dehydrated alfalfa meal(AM) from 21 to 42 days of age. The addition of dietary fiber levels to the broiler chicks diets did noty affect body weight, feed efficiency, energy efficiency and protein efficiency, but affect feed intake of chicks fed 6% of fiber. The level of fiber diets did not affect gizzard weight of female(1.45g/100g BW) and male(1.25g/100g BW), but affect small intestine length of female. When comparing two the dietary fiber levels, 5% and 8%, the contents of the total serum cholesterol was slightly higher in chicks fed 5% of fier than that of 8% without significant. However, total serum cholesterol levels of female(121mg/dl) and male(119mg/dl) were not influenced by increased dietary fiber levels. The liver weight was not influenced by increasing of dietary fiber levels (female 2.03g and male 2.05g/100g BW). The yields of dressed weight(72% of shrunk body weight), skin weight)11% of dressed weight) were not influenced by increased dietary fiber.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3623-3626
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• 2014

Nuclear factor-erythroid 2-related factor 2 (Nrf2) regulates the expression of over 200 genes of antioxidant and phase II drug-metabolizing enzymes, and is highly expressed in non-small cell lung cancer (NSCLC). Nine derivatives of 4-(2-cyclohexylethoxy)aniline were designed. Our previous study demonstrated that IM3829 increases radiosensitivity of several lung cancer cells in vitro and in vivo. Here, biological effects of IM3829 derivatives (2a-2i) were evaluated. Compound 2g derivative effectively inhibits mRNA and protein expression of Nrf2 and HO-1. In addition, we observed over two fold enhancement in IR-induced cell death, from $2.90{\pm}0.22$ to $6.02{\pm}0.87$, in H1299 cancer cell-line. Among the nine derivatives, compound 2g derivative exhibited the highest enhancement of radiosensitizing effect via inhibition of Nrf2 activity.

• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.420-425
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• 2014

Esophageal reflux of gastric contents causes esophageal mucosal damage and inflammation. Recent studies show that oxygen-derived free radicals mediate mucosal damage in reflux esophagitis (RE). Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is one of the most abundant polyphenols in the human diet and possesses anti-inflammatory, antibacterial and anti-oxidant activities. In this context, we investigated the effects of CGA against experimental RE in rats. RE was produced by ligating the transitional region between the forestomach and the glandular portion and covering the duodenum near the pylorus ring with a small piece of catheter. CGA (10, 30 and 100 mg/kg) and omeprazole (positive control, 10 mg/kg) were administered orally 48 h after the RE operation for 12 days. CGA reduced the severity of esophageal lesions, and this beneficial effect was confirmed by histopathological observations. CGA reduced esophageal lipid peroxidation and increased the reduced glutathione/oxidized glutathione ratio. CGA attenuated increases in the serum level of tumor necrosis factor-${\alpha}$, and expressions of inducible nitric oxide synthase and cyclooxygenase-2 protein. CGA alleviates RE-induced mucosal injury, and this protection is associated with reduced oxidative stress and the anti-inflammatory properties of CGA.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.1-15
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• 2010

Progress in the development of DNA vaccines and their delivery strategies has been made since their initial concept as a next generation vaccine. Since DNA vaccine includes non-infectious DNA parts of pathogens, it can't cause disease yet it closely mimic the natural process of infection and immune responses. Despite their early promising results of controlling infectious diseases and cancer in small animal models, DNA vaccines failed to display a level of immunogenicity required for combating these diseases in humans, possibly due to their lower protein expression levels. However, increasing evidence has shown that DNA vaccines are clinically well-tolerated and safe. Furthermore, one notable advantage of DNA vaccines includes convenient utilities of plasmid DNAs coding for antigens. For instance, any emerging pathogens could be prevented easily and timely by allowing the simple exchange of antigen-encoding genes. In this review, newly developed DNA vaccine strategies, including electroporation, which has emerged as a potent method for DNA delivery, targeting infectious diseases and cancer will be discussed with a focus on any on-going DNA vaccine trials or progress made pre-clinically and in clinics.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.1
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• pp.48-56
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• 1992

This studies were carried out to investigate the effects of leaf loading quantity and circulating air volume during bulk curing on the variation of physical and chemical characteristics in flue-cured tobacco. The results are as follows : 1. The content of sugar in cured leaves was decreased with more circulating air volume and leaf loading quantity at bulk curing. 2. Total nitrogen and protein nitrogen were decreased with less circulating air volume and more leaf loading quantity, while amino nitrogen was increased. 3. The contents of linolenic acid and linoleic acid were increased with more leaf loading quantity and oxalic acid and citric acid had a tendency of being increased in case of high circulating air volume. 4. In general, major aromatic compounds were increased through flue-curing. Relatively high content of solanone in case of lower air volume and less leaf loading were observed, while megastig matrienone was increased when leaf loading was small. 5. The more circulation air volume with leaf loading quantity caused lowering equilibrium moisture content and higher shatter index, which resulted in poor quality of cured leaves based on quality index, nitrogen number, taste index phillips index, and sugar-nicotine ratio.