• Journal of Life Science
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• v.29 no.10
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• pp.1120-1125
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• 2019

The short-lived nematode Caenorhabditis elegans has been used as a model organism for many studies, including lifespan extension. To screen common seaweeds for natural anti-aging agents, the lifespan of C. elegans (N2 wild-type strain) was measured by its hatch rate, growth rate, survival rate, chemotaxis, brood size, and egg-laying time after exposure to nematode growth medium (NGM) containing seaweed extracts. Approximately 30 animals synchronized at the first larval stage were incubated until they reached their adult stages before laying their eggs and were transferred to fresh NGM every 3 days. We also identified the major active compound from the seaweed by gas chromatography-mass spectrometry and tested its optimal dose for longevity. Of 13 common seaweed species, an ethanol extract of the brown seaweed Hizikia fusiformis showed the greatest effect on hatching, growth, and survival rates. The lifespan of C. elegans was significantly expanded 1.54-fold and 1.23-fold in the presence of the ethanol extract (0.05 mg/ml) and the main active component, fucosterol (0.05 mg/ml), respectively. Exposure to the ethanol extract also increased chemotaxis 1.13-fold, decreased brood size 0.74-fold, and shortened egg-laying time 0.96-fold. These results suggest that the aquaculturable H. fusiformis may be a promising source of a diet supplement to support health care.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.205-216
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• 2019

Since the RNA interference (RNAi) had been discovered in many organisms, small non-coding RNA-mediated gene silencing technology, including RNAi have been widely applied to analysis of gene function, as well as crop improvement. Despite the usefulness of RNAi technology, RNAi transgenic crops have various potential environmental risks, including off-target and non-target effects. In this study, we developed methods that can be effectively applied to environmental risk assessment of RNAi transgenic crops and verified these methods in 35S::dsRNAi_eGFP rice transgenic plant we generated. Off-target genes, which can be non-specifically suppressed by the expression of dsRNAi_eGFP, were predicted by using the published web tool, pssRNAit, and verified by comparing their expressions between wild-type (WT) and 35S::dsRNAi_eGFP transgenic rice. Also, we verified the non-target effects of the 35S:: dsRNAi_eGFP plant by evaluating horizontal and vertical transfer of small interfering RNAs (siRNAs) produced in the 35S::dsRNAi_eGFP plant into neighboring WT rice and rhizosphere microorganisms, respectively. Our results suggested that the methods we developed, could be widely applied to various RNAi transgenic crops for their environmental risk assessment.

• Korean Journal of Heritage: History & Science
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• v.52 no.1
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• pp.242-257
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• 2019

The Demilitarized Zone (DMZ) stretches two kilometers north and south from the Military Demarcation Line (MDL) of South and North Korea. This area was established as a weapons-free buffer zone when an armistice agreement was signed in 1953. However, there have been several very high-tension military standoffss over the past 65 years. On the South Korean side, civilian access to the Civilian Control Line (CCL) and beyond to the north has been restricted, and natural heritage has been well maintained. Natural heritage is defined as living things, their habitat and non-living things of the ecosystem which deserve to be protected. Research shows that a variety of flora and fauna, their habitat, marshes and geographical structures are found across the DMZ region. Although the DMZ region has not been such a good place for habitat conservation, we can say that this area may be the best location for restoration in terms of its variety of ecosystems and considerable land size. Restoration of course depends on future plans and management policies. This area, including the DMZ and the well-protected north of the CCL, will be the best habitat for endangered species of wild fauna and flora if we classify the various habitat types and create a habitat map. In doing this project, we need to include the estuary of the Han River and the lagoon (brackish water lake) of the East Sea coast. In addition, we must establish long-term plans for conservation and sustainable use and do international scientific research across the DMZ region in collaboration with scientists of South and North Korea and international experts. Mutual cooperation between the two Koreas for investigation and conservation efforts is paramount.

• Journal of Microbiology and Biotechnology
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• v.29 no.1
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• pp.160-170
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• 2019

The lactic acid bacteria species Lactobacillus plantarum (L. plantarum) has been used extensively for vaccine delivery. Considering to the critical role of dendritic cells in stimulating host immune response, in this study, we constructed a novel CD11c-targeting L. plantarum strain with surface-displayed variable fragments of anti-CD11c, single-chain antibody (scFv-CD11c). The newly designed L. plantarum strain, named 409-aCD11c, could adhere and invade more efficiently to bone marrow-derived DCs (BMDCs) in vitro due to the specific interaction between scFv-CD11c and CD11c located on the surface of BMDCs. After incubation with BMDCs, the 409-aCD11c strain harboring a eukaryotic vector pValac-GFP could lead to more efficient expression of GFP compared with wild-type strains shown by flow cytometry analysis, indicating the enhanced translocation of pValac-GFP from L. plantarum to BMDCs. Similar results were also observed in an in vivo study, which showed that oral administration resulted in efficient expression of GFP in both Peyer's patches (PP) and mesenteric lymph nodes (MLNs) within 7 days after the last administration. In addition, the CD11c-targeting strain significantly promoted the differentiation and maturation of DCs, the differentiation of $IL-4^+$ and $IL-17A^+$ T helper (Th) cells in MLNs, as well as production of $B220^+$ $IgA^+$ B cells in the PP. In conclusion, this study developed a novel DC-targeting L. plantarum strain which could increase the ability to deliver eukaryotic expression plasmid to host cells, indicating a promising approach for vaccine study.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.351-361
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• 2019

In our previous study, pyrrolnitrin produced in Pseudomonas chlororaphis G05 plays more critical role in suppression of mycelial growth of some fungal pathogens that cause plant diseases in agriculture. Although some regulators for pyrrolnitrin biosynthesis were identified, the pyrrolnitrin regulation pathway was not fully constructed. During our screening novel regulator candidates, we obtained a white conjugant G05W02 while transposon mutagenesis was carried out between a fusion mutant $G05{\Delta}phz{\Delta}prn::lacZ$ and E. coli S17-1 (pUT/mini-Tn5Kan). By cloning and sequencing of the transposon-flanking DNA fragment, we found that a vfr gene in the conjugant G05W02 was disrupted with mini-Tn5Kan. In one other previous study on P. fluorescens, however, it was reported that the deletion of the vfr caused increased production of pyrrolnitrin and other antifungal metabolites. To confirm its regulatory function, we constructed the vfr-knockout mutant $G05{\Delta}vfr$ and $G05{\Delta}phz{\Delta}prn::lacZ{\Delta}vfr$. By quantifying ${\beta}-galactosidase$ activities, we found that deletion of the vfr decreased the prn operon expression dramatically. Meanwhile, by quantifying pyrrolnitrin production in the mutant $G05{\Delta}vfr$, we found that deficiency of the Vfr caused decreased pyrrolnitrin production. However, production of phenazine-1-carboxylic acid was same to that in the wild-type strain G05. Taken together, Vfr is required for pyrrolnitrin but not for phenazine-1-carboxylic acid biosynthesis in P. chlororaphis G05.

• Korean Journal of Plant Resources
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• v.32 no.2
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• pp.109-115
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• 2019

In this study, we evaluated the anti-cancer activity and potential molecular mechanism of 70% ethanol extracts of branches from Taxillus yadoriki parasitic to Neolitsea sericea (TN-NS-B) against human lung cancer cells, A549. TY-NS-B dose-dependently suppressed the growth of A549 cells. TY-NS-B decreased ${\beta}$-catenin protein level, but not mRNA level in A549 cells. The downregulation of ${\beta}$-catenin protein level by TY-NS-B was attenuated in the presence of MG132. Although TY-NS-B phosphorylated ${\beta}$-catenin protein, the inhibition of $GSK3{\beta}$ by LiCl did not blocked the reduction of ${\beta}$-catenin by TY-NS-B. In addition, TY-NS-B decreased ${\beta}$-catenin protein in A549 cells transfected with Flag-tagged wild type ${\beta}$-catenin or Flag-tagged S33/S37/T41 mutant ${\beta}$-catenin construct. Our results suggested that TN-NS-B may downregulate ${\beta}$-catenin protein level independent on $GSK3{\beta}$-induced ${\beta}$-catenin phosphorylation. Based on these findings, TY-NS-B may be a potential candidate for the development of chemopreventive or therapeutic agents for human lung cancer.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.378-386
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• 2018

GROWTH-REGULATING FACTOR (GRF) genes encode plant-specific transcription factors and play critical roles in regulating the growth and development of lateral organs. In order to explore the agricultural potential of Brassica rapa GRF genes (BrGRFs), we constructed two BrGRF-overexpressing B. napus plants (BrGRF3-1OX and -9OX). BrGRF3-1OX and -9OX developed larger cotyledons, leaves, and seeds than the wild type. The increased organs' sizes were due to increases in cell number, but not due to cell size alterations. RT-PCR analysis revealed that BrGRFs regulated the expression of a wide range of genes that are involved in gibberellin-, auxin-, cell division-related growth processes. Taken together, our data indicate that BrGRFs act as positive regulators of B. napus growth, thus raising the possibility that they may serve as a useful genetic source for crop improvement with respect to organ size and seed production.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.100-109
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• 2021

Objective : Diffuse astrocytic tumour (DAT) is a diffuse infiltrative astrocytoma tumour accompanied by molecular parameters such as the presence or absence of isocitrate dehydrogenase (IDH) gene mutations. Ki-67 is a marker for DAT proliferation, while programmed death ligand 1 (PD-L1) indicates an immune evasion mechanism. This study aimed to analyze the correlation among mutant IDH1 R132H, Ki-67, and PD-L1 immunoexpression in the DAT. Methods : A cross-sectional study was carried out on 30 paraffin blocks of DAT cases. Paraffin block samples consist of grade II (n=14), grade III (n=8), and grade IV (n=8). In this study, the immunohistochemistry-staining of mutant IDH1 R132H, Ki-67, and PD-L1 were carried out to determine the frequency of DAT with IDH1 mutations. Results : Our study shown the frequency of IDH1 mutations in grade II 50.0% (7/14), grade III 37.5% (3/8), and grade IV 12.5% (1/8). Our study also showed a difference in Ki-67 and PD-L1 expression between each the degree of DAT histopathology (p=0.0001 and p=0.002, respectively). There was an association between both mutant IDH1 R132H, and Ki-67 with PD-L1 expression in DAT (p=0.0087 and p=0.0049, respectively). Conclusion : DAT with the mutant IDH1 is frequently observed in grade II and small number of grade III. The expression of wild type IDH1, Ki-67, and PD-L1 were found to be higher in high grade DAT (grade III and grade IV). There is a correlation between each of mutant IDH1 status and Ki-67 with PD-L1 expression in DAT.

• Journal of Life Science
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• v.31 no.1
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• pp.28-36
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• 2021

Edwardsiella piscicida is a significant cause of hemorrhagic septicemia in fish and gastrointestinal infections in humans. Survival bacteria require specialized mechanisms to adapt to environmental fluctuations. Hence, to understand the mechanism through which E. piscicida senses and responds to environmental osmolarity changes, we determined the protein expression profile and physiological properties under various salinity conditions in this study. The OmpR protein is a part of the Env-ZOmpR two-component system that has been implicated in sensing salt stress in bacteria. However, the physiological role played by this protein in E. piscicida remains to be elucidated. Therefore, in this work, the function of the OmpR protein in response to salt stress was investigated. Phenotypic analysis revealed that, in the mutant, three of the biochemical phenotypes were different from the wild type, including, citrate utilization, hydrogen sulfide, and indole production. Introduction of the plasmid containing the entire ompR gene to the mutant strain returned it to its parental phenotype. The retarded growth rate also partially recovered. Furthermore, in our studies, OmpR was not found to be related to cell motility. Taken together, our results from the mutational analysis, the growth assay, MALDI-TOF MS, qRT-PCR, and the phenotype studies suggest that the OmpR of E. piscicida is implicated in osmoregulation, growth, expression of porins (ETAE_1826), virulence-related genes (EseC, EseD and EvpC), and certain genes of unknown function (ETAE_1540 and ETAE_2706).

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1819-1826
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• 2020

Increasing evidence suggests a potential role of microbial colonization in the inception of chronic airway diseases. However, it is not clear whether the lung and gut microbiome dysbiosis is coincidental or a result of mutual interaction. In this study, we investigated the airway microbiome in interleukin 13 (IL-13)-rich lung environment and related alterations of the gut microbiome. IL-13-overexpressing transgenic (TG) mice presented enhanced eosinophilic inflammatory responses and mucus production, together with airway hyperresponsiveness and subepithelial fibrosis. While bronchoalveolar lavage fluid and cecum samples obtained from 10-week-old IL-13 TG mice and their C57BL/6 wild-type (WT) littermates showed no significant differences in alpha diversity of lung and gut microbiome, they presented altered beta diversity in both lung and gut microbiota in the IL-13 TG mice compared to the WT mice. Lung-specific IL-13 overexpression also altered the composition of the gut as well as the lung microbiome. In particular, IL-13 TG mice showed an increased proportion of Proteobacteria and Cyanobacteria and a decreased amount of Bacteroidetes in the lungs, and depletion of Firmicutes and Proteobacteria in the gut. The patterns of polymicrobial interaction within the lung microbiota were different between WT and IL-13 TG mice. For instance, in IL-13 TG mice, lung Mesorhizobium significantly affected the alpha diversity of both lung and gut microbiomes. In summary, chronic asthma-like pathologic changes can alter the lung microbiota and affect the gut microbiome. These findings suggest that the lung-gut microbial axis might actually work in asthma.