• Journal of Marine Bioscience and Biotechnology
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• v.8 no.2
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• pp.45-53
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• 2016

Most of microalgae shift their metabolic pathways toward the fatty acid biosynthesis following nitrogen deprivation. Recent studies on Nannochloropsis species, oleaginous microalgae, have been performed to investigate the regulation of contents and compositions of fatty acids under stressful condition. The objective of this experiment is to identify the effect of nitrogen on cell growth and fatty acids production in Nannochloropsis oculata K-1281 and compare fatty acid composition response to nitrogen deficiency between N. oculata LB2164 and K-1281. The fatty acids content in N. oculata K-1281 was increased up to 210%, while the growth rate was decreased under nitrogen deficient condition. The contents of C16:0 and C16:1 increased dramatically in both N. oculata K-1281 and LB2164, while the contents of C20:4 and C20:5 increased in N. oculata LB2164. The fatty acids content and composition in N. oculata K-1281 returned following addition of nitrogen after nitrogen starvation. These results demonstrated that fatty acid contents and compositions under nitrogen deficiency will provide the understanding of fatty acid synthesis in microalgae.

• Molecules and Cells
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• v.45 no.8
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• pp.537-549
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• 2022

Preproenkephalin (PPE) is a precursor molecule for multiple endogenous opioid peptides Leu-enkephalin (ENK) and Met-ENK, which are involved in a wide variety of modulatory functions in the nervous system. Despite the functional importance of ENK in the brain, the effect of brain-derived factor(s) on PPE expression is unknown. We report the dual effect of neural epidermal growth factor (EGF)-like-like 2 (NELL2) on PPE gene expression. In cultured NIH3T3 cells, transfection of NELL2 expression vectors induced an inhibition of PPE transcription intracellularly, in parallel with downregulation of protein kinase C signaling pathways and extracellular signal-regulated kinase. Interestingly, these phenomena were reversed when synthetic NELL2 was administered extracellularly. The in vivo disruption of NELL2 synthesis resulted in an increase in PPE mRNA level in the rat brain, suggesting that the inhibitory action of intracellular NELL2 predominates the activation effect of extracellular NELL2 on PPE gene expression in the brain. Biochemical and molecular studies with mutant NELL2 structures further demonstrated the critical role of EGF-like repeat domains in NELL2 for regulation of PPE transcription. These are the first results to reveal the spatio-specific role of NELL2 in the homeostatic regulation of PPE gene expression.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.33-41
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• 2022

Esculetin (also known as 6, 7-dihydroxycoumarin) a type of coumarin, has been exhibited anti-inflammatory and anti-aging effects. Biorenovation is the microbe-mediated enhancement of biological efficacies and structurally diversified compounds relative to their substrate compounds. The production of different kinds of esculetin derivatives using Bacillus sp. JD3-7 and their effects on lipopolysaccharide (LPS)-triggered inflammatory response in RAW 26.7 cells were assessed. One of the biorenovation products, identified as esculetin 6-O-phosphate (ESP), at concentrations of 1.25, 2.5, and 5 μM inhibited the LPS-stimulated production of inflammation markers of nitric oxide synthase 2 and cyclooxygenase 2 as well as their respective enzymatic reaction products of nitric oxide and prostaglandin E2 in the order of increasing concentrations (1.25, 2.5, and 5 μM). Additionally, ESP treatment suppressed the LPS-stimulated secretion of pro-inflammatory cytokines of interleukin (IL)-1β, IL-6, and tumor necrosis factor- α. Furthermore, these anti-inflammatory effect of ESP was associated with the downregulation of mitogen-activated protein kinase signaling, that is, extracellular signal-regulated kinase, c-Jun NH2-terminal kinase, and p38 mitogen-activated protein kinase signaling pathways. This study would therefore provide interesting insights into the biorenovation-assisted generation of a novel anti-inflammatory compound. ESP may be used to develop treatments for inflammatory disorders.

• The Plant Pathology Journal
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• v.40 no.1
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• pp.30-39
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• 2024

The conservation of the endangered Korean fir, Abies koreana, is of critical ecological importance. In our previous study, a yeast-like fungus identified as Aureobasidium pullulans AK10, was isolated and shown to enhance drought tolerance in A. koreana seedlings. In this study, the effectiveness of Au. pullulans AK10 treatment in enhancing drought tolerance in A. koreana was confirmed. Furthermore, using transcriptome analysis, we compared A. koreana seedlings treated with Au. pullulans AK10 to untreated controls under drought conditions to elucidate the molecular responses involved in increased drought tolerance. Our findings revealed a predominance of downregulated genes in the treated seedlings, suggesting a strategic reallocation of resources to enhance stress defense. Further exploration of enriched Kyoto Encyclopedia of Genes and Genomes pathways and protein-protein interaction networks revealed significant alterations in functional systems known to fortify drought tolerance, including the terpenoid backbone biosynthesis, calcium signaling pathway, pyruvate metabolism, brassinosteroid biosynthesis, and, crucially, flavonoid biosynthesis, renowned for enhancing plant drought resistance. These findings deepen our comprehension of how AK10 biostimulation enhances the resilience of A. koreana to drought stress, marking a substantial advancement in the effort to conserve this endangered tree species through environmentally sustainable treatment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.111-111
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• 2019

Glycyrrhizae radix is one of the most frequently prescribed ingredients in Oriental medicine, and G. radix extract has been shown to exert anti-cancer effects. However, the cellular and molecular mechanisms of apoptosis by G. radix are poorly defined. In the present study, it was examined the biochemical mechanisms of apoptosis by water extract of G. radix (WEGR) in human bladder T24 cancer cells. It was found that WEGR could inhibit the cell growth of T24 cells in a dose-dependent manner, which was associated with the induction of apoptotic cell death, as evidenced by the formation of apoptotic bodies, DNA fragmentation and increased populations of annexin-V positive cells. The induction of apoptotic cell death by WEGR was connected with an up-regulation of pro-apoptotic Bax protein expression and down-regulation of anti-apoptotic Bcl-2 and Bcl-xL proteins, and inhibition of apoptosis family proteins (XIAP, cIAP-1 and cIAP-2). In addition, apoptosis-inducing concentrations of WEGR induced the activation of caspase-9, an initiator caspase of the mitochondrial-mediated intrinsic pathway, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. WEGR also induced apoptosis via a death receptor-mediated extrinsic pathway by caspase-8 activation, resulting in the down-regulation of total Bid and suggesting the existence of cross-talk between the extrinsic and intrinsic pathways. Taken together, the present results suggest that WEGR may be a potential chemotherapeutic agent for the control of human bladder cancer cells.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.311-318
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• 2015

This work investigated the plasma treatment of aqueous bisphenol A (BPA) solution and mineralization pathways. For the effective contact between plasmatic gas and aqueous BPA solution, the plasma was created inside a porous ceramic tube, which was uniformly dispersed into the aqueous solution through micro-pores of the ceramic tube. Effects of the gas flow rate, applied voltage and treatment time on the decomposition of BPA were examined, and analyses using ultraviolet (UV) spectroscopy, ion chromatography and gas chromatography-mass spectrometry were also performed to elucidate mineralization mechanisms. The appropriate gas flow rate was around $1.0L\;min^{-1}$; when the gas flow rate was too high or too low, the BPA decomposition performance at a given electric power decreased. The increase in the voltage improves the BPA decomposition due to the increased electric power, but the energy required to remove BPA was similar, regardless of the voltage. Under the condition of $1.0L\;min^{-1}$ and 20.8 kV, BPA at an initial concentration of $10L\;min^{-1}$ (volume : 1 L) was successfully treated within 30 min. The intermediates produced by the attack of ozone and hydroxyl radicals on BPA were further oxidized to stable compounds such as acetate, formate and oxalate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.136-141
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• 2009

Biological activities of enzymatic hydrolysate of spirulina (EHS) were investigated. EHS showed no significant effects on the growth-stimulating activity for lactic-acid bacteria and antioxidant activity. EHS showed slight in vitro growth-inhibitory effects (15% at 1.42 mg/L) on a human cervical cancer cell line (HeLa). In addition, the anticoagulant activities of EHS were measured based on three different pathways: common, intrinsic and extrinsic pathways. As an indication of anticoagulant activity on common pathway, thrombin time (TT) of EHS (100 mg/L) was measured as 155.6 sec. Activated partial thromboplastin time (aPTT) for intrinsic pathway of EHS (1,000 mg/L) was measured as 95.8 sec. Prothrombin time (PT) based on extrinsic pathway of EHS (1,000 mg/L) was measured as 10.6 sec. These data showed that EHS have influences on anticoagulant factors of common pathway and intrinsic pathway. Consequently it was found that EHS could be used as a functional food for blood circulation.

• Journal of Life Science
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• v.21 no.2
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• pp.251-256
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• 2011

EGCG, catechins in green tea, is a kind of phytochemical. Through the regulation of signal pathways, EGCG has been known to show anti-oxidant and anti-tumor effects in cells. In this study, we investigated the apoptotic effects of EGCG through AMP-activated protein kinase (AMPK) signal pathways, including hypoxia inducible factor-1 alpha (HIF-$1{\alpha}$). The experiments were performed in B16F10 melanoma cells in a hypoxic state. AMPK is activated by ATP consumption such as nutrient deficiency, exercise, heat shock, etc. The activated AMPK that plays an important role as an energy sensor inhibits proliferation of cancer cells, as well as inducing apoptosis. HIF-$1{\alpha}$, the primary transcriptional regulator of the response to oxygen deprivation, plays a critical role in modulating tumor growth and angiogenesis in a hypoxic state. The apoptotic effects of EGCG were studied in B16F10 cells in a hypoxic state. The results show that EGCG inhibits the transcriptional activity of HIF-$1{\alpha}$ and induces apoptosis. These observations suggest that EGCG may exert inhibitory effects of angiogenesis and control tumor cell growth in hypoxic melanoma cells.

• Animal cells and systems
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• v.8 no.3
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• pp.213-220
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• 2004

MicroRNA and siRNA (small interfering RNA), representative members of small RNA, exert their effects on target gene expression through association with protein complexes called miRNP (microRNA associated ribonucleoproteins) and RISC (RNA induced silencing complex), respectively. Although the protein complexes are yet to be fully characterized, human EIF2C2 protein has been identified as a component of both miRNP and RISC. In this report, we raised antiserum against EIF2C2 in order to begin understanding the protein complexes. An immunoblot result indicates that EIF2C2 protein is ubiquitously expressed in a variety of cell lines from human and mouse. EIF2C2 protein exists in both cellular compartments, as indicated by an immunoblot assay with a nuclear extract and a cytosolic fraction (S100 fraction) from HeLa S3 lysate. Depletion of EIF2C1 or EIF2C2 protein resulted in a decrease of microRNA, suggesting a possible role of these proteins in microRNA stability or biogenesis. We also prepared antiserum against dsRNA binding protein PACT, whose homologs in C. elegans and Drosophila are known to have a role in the RNAi (RNA interference) pathway. The expression of PACT protein was also observed in a wide range of cell lines.

• BMB Reports
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• v.53 no.8
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• pp.425-430
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• 2020

Tumor necrosis factor-inducible gene 6 protein (TSG-6) is a cytokine secreted by mesenchymal stem cells (MSCs) and regulates MSC stemness. We previously reported that TSG-6 changes primary human hepatic stellate cells (pHSCs) into stem-like cells by activating yes-associated protein-1 (YAP-1). However, the molecular mechanism behind the reprogramming action of TSG-6 in pHSCs remains unknown. Cluster of differentiation 44 (CD44) is a transmembrane protein that has multiple functions depending on the ligand it is binding, and it is involved in various signaling pathways, including the Wnt/β-catenin pathway. Given that β-catenin influences stemness and acts downstream of CD44, we hypothesized that TSG-6 interacts with the CD44 receptor and stimulates β-catenin to activate YAP-1 during TSG-6-mediated transdifferentiation of HSCs. Immunoprecipitation assays showed the interaction of TSG-6 with CD44, and immunofluorescence staining analyses revealed the colocalization of TSG-6 and CD44 at the plasma membrane of TSG-6-treated pHSCs. In addition, TSG-6 treatment upregulated the inactive form of phosphorylated glycogen synthase kinase (GSK)-3β, which is a negative regulator of β-catenin, and promoted nuclear accumulation of active/nonphosphorylated β-catenin, eventually leading to the activation of YAP-1. However, CD44 suppression in pHSCs following CD44 siRNA treatment blocked the activation of β-catenin and YAP-1, which inhibited the transition of TSG-6-treated HSCs into stem-like cells. Therefore, these findings demonstrate that TSG-6 interacts with CD44 and activates β-catenin and YAP-1 during the conversion of TSG-6-treated pHSCs into stem-like cells, suggesting that this novel pathway is an effective therapeutic target for controlling liver disease.