• Molecules and Cells
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• v.39 no.5
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• pp.418-425
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• 2016

Resveratrol (RES) plays a critical role in the fate of cells and longevity of animals via activation of the sirtuins1 (SIRT1) gene. In the present study, we intend to investigate whether RES could promote the self-renewal and neural-lineage differentiation in human umbilical cord derived MSCs (hUC-MSCs) in vitro at concentrations ranging from 0.1 to $10{\mu}M$, and whether it exerts the effects by modulating the SIRT1 signaling. Herein, we demonstrated that RES at the concentrations of 0.1, 1 and $2.5{\mu}M$ could promote cell viability and proliferation, mitigate senescence and induce expression of SIRT1 and Proliferating Cell Nuclear Antigen (PCNA) while inhibit the expression of p53 and p16. However, the effects were reversed by 5 and $10{\mu}M$ of RES. Furthermore, RES could promote neural differentiation in a dose-dependent manner as evidenced by morphological changes and expression of neural markers (Nestin, ${\beta}III-tubulin$ and NSE), as well as pro-neural transcription factors Neurogenin (Ngn)1, Ngn2 and Mash1. Taken together, RES exerts a dosage-dependent effect on the self-renewal and neural differentiation of hUC-MSCs via SIRT1 signaling. The current study provides a new strategy to regulate the fate of hUC-MSCs and suggests a more favorable in vitro cell culture conditions for hUCMSCs-based therapies for some intractable neurological disorders.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1972-1984
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• 2013

Microtubules play an important role in intracellular transport, mobility, and particularly mitosis. Paclitaxel (Taxol$^{TM}$) and paclitaxel-like compounds have been shown to be anti-tumor agents useful for various human tumors. Paclitaxel-like compounds operate by stabilizing microtubules through interface binding at the interface between two ${\beta}$-tubulin monomers in adjacent protofilaments. In this paper we present the elucidation of the structural features of paclitaxel and paclitaxel-like compounds (e.g., epothilones) with microtubule stabilizing activities, and relate their activities to spatial and chemical features of the molecules. CATALYST program was used to generate three-dimensional quantitative structure activity relationships (3D-QSARs) resulting in 3D pharmacophore models of epothilone- and paclitaxel-derivatives. Pharmacophore models were generated from diverse conformers of these compounds resulting in a high correlation between experimental and predicted biological activities (r = 0.83 and 0.91 for epothilone and paclitaxel derivatives, respectively). On the basis of biological activities of the training sets, five- and four-feature pharmacophore hypotheses were generated in the epothilone and paclitaxel series. The validation of generated hypotheses was achieved by using twelve epothilones and ten paclitaxels, respectively, which are not in the training sets. The clustering (grouping) and merging techniques were used in order to supplement spatial restrictions of each of hypothesis and to develop more comprehensive models. This approach may be of use in developing novel inhibitor candidates as well as contributing a better understanding of structural characters of many compounds useful as anticancer agents targeting microtubules.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.1
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• pp.75-81
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• 2004

Objective: The purpose of this study was to evaluate the efficacy and effect of various cryopreservation method on the survival and the cytoskeletal stability of metaphase II mouse oocyte. Methods: Mouse ovulated oocytes were collected and cryopreserved by a modified slow-freezing method with 1.5 M 1, 2-propanediol (PrOH)+0.1 M sucrose or by vitrification using cryo loop and EM grid with 40% ethylene glycol+0.6 M sucrose. Four hours after thawing, intact oocytes were fixed and stained with fluorescein isothiocyanate (FITC)-conjugated monoclonal anti-$\beta$-tubulin antibody to visualize spindle and propidium iodide (PI) to visualize chromosome. Spindle morphology was classified as follows: normal (barrel-shaped), slightly and absolute abnormal (multipolar or absent). Results: Survival rate of the frozen-thawed oocytes in vitrification group was significantly higher than that of slow-freezing group (62.7% vs. 24.4%, p<0.01). Vitrification with cryo loop showed significantly higher survival rate than that with EM grid (67.7% vs. 53.5%, p<0.05). On the other hand, proportion of normal spindle and chromosome configurations of the frozen-thawed oocytes between two vitrification group was not significantly different. Conclusion: For mouse ovulated oocytes, vitrification with cryo loop may be a preferable procedure compared to slow-freezing method. Further study should be needed to investigate developmental competency of frozen-thawed mouse oocytes.

• Research in Plant Disease
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• v.26 no.3
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• pp.190-193
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• 2020

In 2014, Anthracnose symptoms were observed on fruit of pumpkin in Gangneung, Gangwon in Korea. The typical symptoms on fruit surfaces were circular lesions, brown, shriveled with salmon-colored spore masses on the spots. A fungal isolate was obtained from symptomatic on fruit and cultured on potato dextrose agar at 25℃. The color of the upper surface of the colony varied from white to gray with occurrence of salmon-colored conidial masses and was red to violet on the underside. The causal fungus of anthracnose isolated from the diseased fruits was identified as Colletotrichum fioriniae based on mycological characteristics and sequences of the internal transcribed spacer, glyceraldehyde-3-phosphate dehydrogenase, chitin synthase-1 gene, histone H3, actin gene, beta-tubulin gene region. Pathogenicity tests of the isolate were performed on pumpkin fruit by both wound and non-wound inoculation with conidial suspension (1×10⁶ conidia/ml) and incubated at 25℃. Lesions were observed on both wounded and non-wounded fruit of pumpkin after 7 days inoculation in only C. fioriniae. The pathogen was re-isolated from the lesions of inoculated fruits. To our knowledge, this is the first report of anthracnose on fruit of pumpkin caused by C. fioriniae in Korea.

• Biomolecules & Therapeutics
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• v.18 no.4
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• pp.386-395
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• 2010

Bone marrow-derived mesenchymal stem cells (BM-MSC) are a multipotent cell population that can differentiate into neuron-like cells. Previously it has been reported that murine BM-MSC can differentiate into neuron-like cells by co-treatment with a Rho-associated kinase (ROCK) inhibitor -Y27632 and $CoCl_2$. In this study, we compared several ROCK inhibitors for the ability to induce human BM-MSCs to differentiate into neuron-like cells in the presence of $CoCl_2$. Y27632 with high specificity for ROCK at 1-30 ${\mu}M$ was best at inducing neuronal differentiation of MSCs. Compared to HA1077 and H1152, which also effectively induced morphological change into neuron-like cells, Y27632 showed less toxicity even at 100 ${\mu}M$, and resulted in longer multiple branching processes at a wide range of concentrations at 6 h and 72 h post-induction. H89, however, which has less specificity by inhibition of protein kinase A, S6 kinase 1 and MSK1 with similar or greater potency, was less effective at inducing neuronal differentiation of MSCs. Simvastatin, which can inhibit Rho, Ras, and Rac by blocking the synthesis of isoprenoid intermediates, showed little activity for inducing morphological changes of MSCs into neuron-like cells. Accordingly, the expression patterns for neuronal cell markers,including ${\beta}$-tubulin III, neuron-specific enolase, neurofilament, and microtubule-associated protein, were consistent with the pattern of the morphological changes. The data suggest that the ROCK inhibitors with higher specificity are more effective at inducing neuronal differentiation of MSCs.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1687-1695
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• 2016

Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified as Aspergillus tubingensis M036 and M074 through sequence analysis of the beta-tubulin gene. After culturing both A. tubingensis isolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). Both A. tubingensis strains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by the A. tubingensis strains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest that A. tubingensis isolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.57-66
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• 2017

Aflatoxins are classified as Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer. In this study, a total of 134 fungal strains were isolated from 65 meju samples, and two fungal isolates were selected as potential aflatoxin $B_1$ ($AFB_1$)-biodetoxification fungi. These fungi were identified as Aspergillus oryzae MAO103 and A. oryzae MAO104 by sequencing the beta-tubulin gene. The two A. oryzae strains were able to degrade more than 90% of $AFB_1$ (initial concentration: $40{\mu}g/l$) in a culture broth in 14 days. The mutagenic effects of $AFB_1$ treated with A. oryzae MAO103 and MAO104 significantly decreased to 5.7% and 6.4%, respectively, in the frame-shift mutation of Ames tests using Salmonella typhimurium TA98. The base-substituting mutagenicity of $AFB_1$ was also decreased by the two fungi. Moreover, $AFB_1$ production by Aspergillus flavus was significantly decreased by the two A. oryzae strains on soybean-based agar plates. Our data suggest that the two $AFB_1$-detoxifying A. oryzae strains have potential application to control $AFB_1$ in foods and feeds.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1270-1279
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• 2011

Bealmijang is a short-term aged paste made from meju, which is a brick of fermented soybeans and other ingredients. Different types of bealmijang are available depending on the geographic region or ingredients used. However, no study has clarified the microbial diversity of these types. We identified 17 and 14 fungal species from black soybean meju (BSM) and buckwheat meju (BWM), respectively, on the basis of morphology, culture characteristics, and internal transcribed spacer and ${\beta}$-tubulin gene sequencing. In both meju, Aspergillus oryzae, Rhizopus oryzae, Penicillium polonicum, P. steckii, Cladosporium tenuissimum, C. cladosporioides, C. uredinicola, and yeast species Pichia burtonii were commonly found. Moreover, A. flavus, A. niger, P. crustosum, P. citrinum, Eurotium niveoglaucum, Absidia corymbifera, Setomelanomma holmii, Cladosporium spp. and unclassified species were identified from BSM. A. clavatus, Mucor circinelloides, M. racemosus, P. brevicompactum, Davidiella tassiana, and Cladosporium spp. were isolated from BWM. Fast growing Zygomycetous fungi is considered important for the early stage of meju fermentation, and A. oryae and A. niger might play a pivotal role in meju fermentation owing to their excellent enzyme productive activities. It is supposed that Penicillium sp. and Pichia burtonii could contribute to the flavor of the final food products. Identification of this fungal diversity will be useful for understanding the microbiota that participate in meju fermentation, and these fungal isolates can be utilized in the fermented foods and biotechnology industries.

• Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.21.1-21.11
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• 2016

Background: The evaluation of suitable reference genes as normalization controls is a prerequisite requirement for launching quantitative reverse transcription-PCR (RT-qPCR)-based expression study. In order to select the stable reference genes in abalone Haliotis discus hannai tissues (gill and hepatopancreas) under heavy metal exposure conditions (Cu, Zn, and Cd), 12 potential candidate housekeeping genes were subjected to expression stability based on the comprehensive ranking while integrating four different statistical algorithms (geNorm, NormFinder, BestKeeper, and ${\Delta}CT$ method). Results: Expression stability in the gill subset was determined as RPL7 > RPL8 > ACTB > RPL3 > PPIB > RPL7A > EF1A > RPL4 > GAPDH > RPL5 > UBE2 > B-TU. On the other hand, the ranking in the subset for hepatopancreas was RPL7 > RPL3 > RPL8 > ACTB > RPL4 > EF1A > RPL5 > RPL7A > B-TU > UBE2 > PPIB > GAPDH. The pairwise variation assessed by the geNorm program indicates that two reference genes could be sufficient for accurate normalization in both gill and hepatopancreas subsets. Overall, both gill and hepatopancreas subsets recommended ribosomal protein genes (particularly RPL7) as stable references, whereas traditional housekeepers such as ${\beta}-tubulin$ (B-TU) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were ranked as unstable genes. The validation of reference gene selection was confirmed with the quantitative assay of MT transcripts. Conclusions: The present analysis showed the importance of validating reference genes with multiple algorithmic approaches to select genes that are truly stable. Our results indicate that expression stability of a given reference gene could not always have consensus across tissue types. The data from this study could be a good guide for the future design of RT-qPCR studies with respect to metal regulation/detoxification and other related physiologies in this abalone species.

• Journal of Korean Neurosurgical Society
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• v.38 no.2
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• pp.121-125
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• 2005

Objective : Many recent reports have shown that the mature mammalian brain harbors multipotent stem cells, rendering the brain capable of generating new neurons and glia throughout life. Harvested stem cells from an adult rat are transplanted in order to evaluate the cell survival and differentiation. Methods : Using a percoll gradient with a high speed centrifugation method, we isolate neural stem/progenitor cells were isolated from the subventricular zone[SVZ] of a syngeneic adult Fisher 344 rats brain. For 14days expansion, the cultured cells comprised of a heterogeneous population with the majority of cells expressing nestin and/or GFAP. After expanding the SVZ cells in the presence of basic fibroblast growth factor-2, and transplanting then into the hippocampus of normal rats, the survival and differentiation of those cells were examined. For transplantation, the cultured cells were labeled with BrdU two days prior to use. In order to test their survival, the cells were transplanted into the dorsal hippocampus of normal adult Fisher 344 rats. Results : The preliminary data showed that at 7days after transplantation, BrdU+ transplanted cells were observed around the injection deposition sites. Immuno-fluorescent microscopy revealed that the cells co-expressed BrdU+ and neuronal marker ${\beta}$-tubulin III. Conclusion : The data demonstrate that the in vitro expanded SVZ cells can survive in a heterotypic environment and develop a neuronal phenotype in the neurogenic region. However more research will be needed to examine the longer survival time points and quantifying the differentiation in the transplanted cells in an injured brain environment.