• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7363-7369
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• 2014

The present study aimed to prepare and evaluate polymeric micelles conjugated with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups for antitumor efficacy. The isomeric block copolymers, ${\alpha}$- and ${\gamma}$-folate-polyethyleneglycol-distearoyl phosphatidylethanolamine (${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE), were produced by solid phase peptide synthesis. Three types of doxorubicin (DOX)-loaded polymeric micelles (MPEG-DSPE-DOX and ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPEDOX micelles) were prepared via the film formation method. Compared with MPEG-DSPE-DOX micelles, the ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPE-DOX micelles presented a higher cellular uptake behavior in the live cell study. Cell viability percentages were 81.8%, 57.3%, 56.6% at 2 hours for MPEG-DSPE-DOX, ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles, respectively (p<0.05). Using the KB xenograft tumor model, both ${\alpha}$- and ${\gamma}$-folate-conjugated micelles were found to have better antitumor effects with lower toxicity in comparison with MPEG-DSPE-DOX micelles. No difference in in vivo antitumor efficacy was found between ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles. The folate-conjugated micelles might be a potentially useful strategy for tumor targeting of therapeutic agents, whether grafting with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.71-80
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• 2005

Effects of low temperature ($8^{\circ}C$) on the hydraulic conductivity of young roots of a chilling-sensitive (cucumber; Cucumis sativus L.) and a chilling-resistant (figleaf gourd; Cucurbita ficifolia Bouche) crop have been measured at the levels of whole root systems (root hydraulic conductivity, $Lp_r$) and of individual cortical cells (cell hydraulic conductivity, Lp). In figleaf gourd, there was a reduction only in hydrostatic $Lp_r$ but not in osmotic $Lp_r$ suggesting that the activity of water channels was not much affected by low root temperature (LRT)treatment in this species. Changes in cell Lp in response to chilling and recovery were similar asroot level, although they were more intense at the root level. Roots of figleaf gourd recovered better from LRT treatment than those of cucumber. In figleaf gourd, recovery (both at the root and cell level) often resulted in Lp and $Lp_r$ values which were even bigger than the original, i.e. there was an overshoot in hydraulic conductivity. These effects were larger forosmotic (representing the cell-to-cell passage of water) than for hydrostatic $Lp_r$. After a short term (1 d) exposure to $8\;^{\circ}C$ followed by 1 d at $20\;^{\circ}C$, hydrostatic $Lp_r$ of cucumber nearly recovered and that of figleaf gourd still remained higher due to the overshoot. On the contrary, osmotic $Lp_r$ and cell Lp in both species remained high by a factor of 3 as compared to the control, possibly due to an increased activity of water channels. After pre-conditioning of roots at LRT, increased hydraulic conductivitywas completely inhibited by $HgCl_2$ at both the root and cell levels. Different from figleaf gourd, recovery from chilling was not complete in cucumber after longer exposure to LRT. It is concluded that at LRT, both changes in the activity of aquaporins and alterations of root anatomy determine the water uptake in both species. To better understand the aquaporin function in plants under various stress conditions, we examined the transgenic Arabidopsisand tobacco plants that constitutively overexpress ArabidopsisPIP1;4 or PIP2;5 under various abiotic stress conditions. No significant differences in growth rates were found between the transgenic and wild-type plants under favorable growth conditions. By contrast, overexpression of PIP1;4 or PIP2;5 had a negative effect on seed germination and seedling growth under drought stress, whereas it had a positive effect under cold stress and no effect under salt stress. Measurement of water transport by cell pressure probe revealed that these observed phenotypes under different stress conditions were closely correlated with the ability of water transport by each aquaporin in the transgenic plants. Together, our results demonstrate that PIP-type aquaporins play roles in seed germination, seedling growth, and stress response of Arabidopsis and tobacco plants under various stress conditions, and emphasize the importance of a single aquaporin-mediated water transport in these cellular processes.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6039-6046
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• 2015

Aims: To investigate effect of metallic nanoparticles, silver (AgNPs) and gold nanoparticles (AuNPs) as antitumor treatment in vitro against human breast cancer cells (MCF-7) and their associated mechanisms. This could provide new class of engineered nanoparticles with desired physicochemical properties and may present newer approaches for therapeutic modalities to breast cancer in women. Materials and Methods: A human breast cancer cell line (MCF-7) was used as a model of cells. Metallic nanoparticles were characterized using UV-visible spectra and transmission electron microscopy (TEM). Cytotoxic effects of metallic nanoparticles on MCF-7 cells were followed by colorimetric SRB cell viability assays, microscopy, and cellular uptake. Nature of cell death was further investigated by DNA analysis and flow cytometry. Results: Treatment of MCF-7 with different concentrations of 5-10nm diameter of AgNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $6.28{\mu}M$, whereas treatment of MCF-7 with different concentrations of 13-15nm diameter of AuNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $14.48{\mu}M$. Treatment of cells with a IC50 concentration of AgNPs generated progressive accumulation of cells in the S phase of the cell cycle and prevented entry into the M phase. The treatment of cells with IC50 concentrations of AuNPs similarly generated progressive accumulation of cells in sub-G1 and S phase, and inhibited the entrance of cells into the M phase of the cell cycle. DNA fragmentation, as demonstrated by electrophoresis, indicated induction of apoptosis. Conclusions: Our engineered silver nanoparticles effectively inhibit the proliferation of human breast carcinoma cell line MCF-7 in vitro at high concentration ($1000{\mu}M$) through apoptotic mechanisms, and may be a beneficial agent against human carcinoma but further detailed study is still needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1367-1374
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• 2005

Amino acid transporters play an important role in supplying nutrition to normal and cancer cells for cell proliferation. Amino acid transport system L is a major nutrient transport system responsible for the $Na^+$-independent transport of neutral amino acids including several essential amino acids. The system L is divided into two major subgroups, the L-tyre amino acid transporter 1 (LAT1) and the L-type amino acid transporter 2 (LAT2). In the present study, we have examined the expression and functional characterization of system L amino acid transporters in FOB human osteoblast cells. RT-PCR and western blot analysis have revealed that the FOB cells expressed LAT1, LAT2 together with their associating protein 4F2hc. The uptakes of $[^{14}C]_L$-leucine by FOB cells are $Na^+$-independent and almost completely inhibited by system L amino acid transporter selective inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). These results suggest that the transport of neutral amino acids including several essential amino acids for cellular nutrition into the FOB human osteoblast cells is mediated by system L amino acid transporters.

• Applied Microscopy
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• v.40 no.4
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• pp.201-209
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• 2010

Korean traditional herbs, especially Anemarrhena asphodeloides (A. asphodeloides), Salvia miltiorrhiza (S. miltiorrhiza), and Terminalia chebula (T. chebula) have been known to have the immunomodulatory, anti-tumor, and anti-inflammatory effects. However, direct cellular mechanism underlying the mast cell-mediated anaphylaxis-like reaction has poorly been understood. In the present study, the effects of the methanol extracts of A. asphodeloides (MEAA), S. miltiorrhiza (MESM), and T. chebula (METC) on anaphylactic reaction were investigated. Using in vitro and in vivo experiments, the influences of MEAA, MESM, and METC on the compound 48/80-induced anaphylaxis-like reaction and mast cell activation, and IgEmediated PCA were examined. Results are below; 1) MEAA, MESM, and METC significantly inhibited systemic anaphylaxis-like reaction, ear swelling response, and IgE-mediated PCA. 2) the compound 48/80-induced mast cell degranulation, histamine release of rat peritoneal mast cells (RPMC) were significantly inhibited by the pretreatment with MEAA, MESM, and METC, and 3) the compound 48/80-induced calcium influx in RPMC was significantly inhibited by the pretreatment with MEAA, MESM, and METC. These results suggest that MEAA, MESM, and METC may be an activity to inhibit the compound 48/80-induced or anti-DNP IgE-mediated anaphylactic reactions by blocking histamine release and calcium uptake into RPMC. MEAA, MESM, and METC potentially may serve as an effective therapeutic tool for allergic diseases.

• Journal of Life Science
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• v.26 no.12
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• pp.1470-1476
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• 2016

The viral hemorrhagic septicemia virus (VHSV), which belongs to the Novirhabdovirus genus of the Rhabdoviridae family, is a viral pathogen that causes severe losses in the olive flounder farming industry. Among six encoding VHSV proteins, the non-virion (NV) protein has been shown to have an impact on virulence. In our previous studies, transcriptomics microarray analysis by using VHSV-infected olive flounder showed that VHSV infection significantly down-regulated the mRNA expression of glycolytic enzymes. In addition, VHSV NV protein variants decreased the intracellular ATP level. Based on these results, we have tried to examine the effect of VHSV NV protein on glycolytic enzyme glucokinase expression, which phosphorylates glucose to glucose 6-phosphate. Our results indicated that the NV protein significantly decreased the mRNA expression of glucokinase in olive flounder HINAE cells. Furthermore, the NV protein played a negative role in the promoter activation of glucokinase. Furthermore, glucose uptake was effectively inhibited by VHSV infection and NV protein expression in olive flounder HINAE cells. These results suggest that the VHSV NV protein negatively regulates glycolytic enzyme expression by a transcription level and eventually leads to gradual morbidity of olive flounder through cellular energy deprivation. The present results may be useful for the prevention and diagnosis of VHSV infection in olive flounder.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.123-133
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• 2017

The development of a new manufacturing process, a two-step temperature treatment, to modulate the physicochemical properties of nanoparticles including the size is critical. This is because its physicochemical properties can be key factors affecting the cellular uptake and the bioavailability of bioactive compounds encapsulated in nanoparticles. The aims of this study were to produce (beta-lactoglobulin) ${\beta}-lg$ nanoparticles and to understand how two-step temperature treatment could affect the formation and physicochemical properties of ${\beta}-lg$ nanoparticles. The morphological and physicochemical properties of ${\beta}-lg$ nanoparticles were determined using atomic force microscopy and a particle size analyzer, respectively. Circular dichroism spectroscopy was used to investigate the secondary structure of ${\beta}-lg$. The surface hydrophobicity and free thiol groups of ${\beta}-lg$ were increased with a decrease in sub-ambient temperature and an increase in mild heat temperature. As sub-ambient temperature was decreased, a decrease in ${\alpha}-helical$ content and an increase in ${\beta}-sheet$ content were observed. The two-step temperature treatment firstly involved a sub-ambient temperature treatment from 5 to $20^{\circ}C$ for 30 min, followed secondly by a mild heat temperature treatment from 55 to $75^{\circ}C$ for 10 min. This resulted in the production of spherically-shaped particles with a size ranging from 61 to 214 nm. Two-way ANOVA exhibited the finding that both sub-ambient and mild heat temperature significantly (p<0.0001) affected the size of nanoparticles. Zeta-potential values of ${\beta}-lg$ nanoparticles were reduced with increasing mild heat temperature. In conclusion, two-step temperature treatment was shown to play an important role in the manufacturing process - both due to its inducement of the conformational changes of ${\beta}-lg$ during nanoparticle formation, and due to its modulation of the physicochemical properties of ${\beta}-lg$ nanoparticles.

• Journal of Life Science
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• v.22 no.9
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• pp.1159-1165
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• 2012

The action of neuronally released ${\gamma}$-aminobutyric acid (GABA) is terminated by uptake into the neurons by GABA transporters (GATs). The mechanism underlying the stabilization and regulation of GAT2 has not yet been elucidated. We used the yeast two-hybrid system to identify proteins that interact with and, thereby, regulate betaine-${\gamma}$-aminobutyric acid transporter 1 (BGT-1/mGAT2). We found an interaction between BGT-1/mGAT2 and Munc-18-interacting proteins (Mints). The "T-H-L" motif at the C-terminal end of BGT-1/mGAT2 was essential for the interaction with Mint2 in the yeast two-hybrid assay. Mint2 bound to the tail region of BGT-1/mGAT2, but not to other GAT members. When co-expressed in HEK-293T cells, Mint2 was co-immunoprecipitated with BGT-1/mGAT2. In addition, we demonstrated the cellular co-localization of BGT-1/mGAT2 and Mint2 in the cells. These results suggest that Mint2 contributes to the regulation of BGT-1/mGAT2.

• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1782-1789
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• 2012

We have developed a novel type of polymer nanogel loaded with anticancer drug based on bio-derived poly(${\gamma}$-glutamic acid) (${\gamma}$-PGA). ${\gamma}$-PGA is a highly anionic polymer that is synthesized naturally by microbial species, most prominently in various bacilli, and has been shown to have excellent biocompatibility. Thiolated ${\gamma}$-PGA was synthesized by covalent coupling between the carboxyl groups of ${\gamma}$-PGA and the primary amine group of cysteamine. Doxorubicin (Dox)-loaded ${\gamma}$-PGA nanogels were fabricated using the following steps: (1) an ionic nanocomplex was formed between thiolated ${\gamma}$-PGA as the negative charge component, and Dox as the positive charge component; (2) addition of poly(ethylene glycol) (PEG) induced hydrogen-bond interactions between thiol groups of thiolated ${\gamma}$-PGA and hydroxyl groups of PEG, resulting in the nanocomplex; and (3) disulfide crosslinked ${\gamma}$-PGA nanogels were fabricated by ultrasonication. The average size and surface charge of Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels in aqueous solution were $136.3{\pm}37.6$ nm and $-32.5{\pm}5.3$ mV, respectively. The loading amount of Dox was approximately 38.7 ${\mu}g$ per mg of ${\gamma}$-PGA nanogel. The Dox-loaded disulfide cross-linked ${\gamma}$-PGA nanogels showed controlled drug release behavior in the presence of reducing agents, glutathione (GSH) (1-10 mM). Through fluorescence microscopy and FACS, the cellular uptake of ${\gamma}$-PGA nanogels into breast cancer cells (MCF-7) was analyzed. The cytotoxic effect was evaluated using the MTT assay and was determined to be dependent on both the concentration and treatment time of ${\gamma}$-PGA nanogels. The bio-derived ${\gamma}$-PGA nanogels are expected to be a well-designed delivery carrier for controlled drug delivery applications.

• Journal of Life Science
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• v.32 no.3
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• pp.256-262
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• 2022

Oxysterols are oxygenated metabolites of cholesterol generated by serial enzymatic reactions during bile acid synthesis. Similar to cholesterol, oxysterols move rapidly to the intracellular region and modulate various cellular processes, such as immune cell responses, lipid metabolism, and cholesterol homeostasis. Different nuclear transcription factors, such as glucocorticoid, estrogen, and liver X receptors, can be modulated by oxysterols in multiple tissues. The most abundant oxysterol, 27-hydroxycholesterol (27-OHC), is a well-known selective modulator that can either activate or suppress estrogen receptor activity in a tissue-specific manner. The contribution of 27-OHC in atherosclerosis development is apparent because a large amount of it is found in atherosclerotic plaques, accelerating the transformation of macrophages into foam cells that uptake extracellular modified lipids. According to previous studies, however, there are opposing opinions about how 27-OHC affects lipid and cholesterol metabolism in metabolic organs, including the liver and adipose tissue. In particular, the effects of 27-OHC on lipid metabolism are entirely different between in vitro and in vivo conditions, suggesting that understanding the physiology of this oxysterol requires a sophisticated approach. This review summarizes the potential effects of 27-OHC in atherosclerosis and metabolic syndromes with a special discussion of its role in metabolic tissues.