Korea Research Institute of Bioscience and Biotechnology
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A novel ethylene-responsive factor IbERF4 from sweetpotato negatively regulates abiotic stress
No full textThe ERF (ethylene-responsive element-binding factor) transcription factor family plays important roles in abiotic and biotic stress responses in plants. An EAR motif-containing ERF gene, IbERF4, was isolated from sweetpotato [Ipomoea batatas (L.) Lam]. IbERF4 was highly expressed in the early stage of storage roots and can be induced by various stresses. By overexpressing IbERF4 in Arabidopsis, the transgenic Arabidopsis showed greater sensitivity to drought and salt stress by down-regulating stress-related genes, such as rd22, rd29, AtCBF1 and AtCBF2. Overexpressing IbERF4 in sweetpotato made the transgenic sweetpotato more sensitive to salt stress and made propagating new seedlings more difficult. Consistently, the transcriptomic profiling results showed that genes involved in oxidative stress were significantly down-regulated in sweetpotato overexpression lines. These results indicated that IbERF4 plays as key regulators in sweetpotato abiotic stress.
Flexible chemical sensors using signal generation from cyclodextrin-analyte interactions on polymer composites
No full textWe present the design of a chemical sensor and study the generation of electrical signals produced by the formation of a cyclodextrin inclusion complex. Flexible poly(dimethylsiloxane)/graphene hybrid composites were used as sensor substrates and sensing media, beta-cyclodextrin (beta-CD) molecules were incorporated using simple bio-coupling reactions. The feasibility of sensing molecules through the formation of beta-CD/analyte inclusion complexes was investigated systematically using direct electrical measurement. The acquisition and transduction of electrical signals generated by inclusion complex formation is a central focus of this study and extensive complementary experiments were carried out to characterize this phenomenon. Because it is useful for development of a sort of sensor system, electrical measurements were performed to measure the sensitivity of this system (10 nM). However, more study is required to determine the selectivity. This article will be a useful reference for the design of versatile chemical sensors utilizing a non-toxic sensing medium on flexible composite substrates.
The combination of forskolin and VPA increases gene expression efficiency to the hypoxia/neuron-specific system
No full textBackground: Spinal cord injury (SCI) tends to damage neural tissue and generate a hypoxic environment. Studies have confirmed that single therapy with gene or stem cells is inefficient, but research into combining stem cells and gene therapy in treating tissue damage has been undertaken to overcome the related limitations, which include low gene delivery efficiency and therapeutic outcome. Thus, a combination of stem cells, gene therapy, and a hypoxia-specific system may be useful for the reconstruction of SCI.
Methods: To synergistically treat SCI, a combined platform using a hypoxia/neuron-inducible gene expression system (HNIS) and human induced-neural stem cells (hiNSCs) produced by direct reprogramming was designed. Sox2- or nestin-positive hiNSCs were differentiated to Tuj1-, MAP2-, or NeuN-positive neurons.
Results: HNIS showed consistent hypoxia/neuron-specific gene expression in hiNSCs cultured under hypoxia. In particular, the HNIS-hiNSC combined platform revealed a complex pattern with higher gene expression compared with a single platform. In addition, we found that an optimal combination of small molecules, such as CHIR99021, valproic acid (VPA), glycogen synthase kinase-3β (GSK3β), and histone deacetylase (HDAC) inhibitors, could significantly enhance gene expression with HNIS-hiNSCs in the hypoxic environment.
Conclusions: This experiment demonstrated that HNIS-hiNSCs combined with GSK3 and HDAC inhibitors may present another promising strategy in the treatment of SCI.
Aureimonas fodinaquatilis sp. nov., isolated from coal mine wastewater
No full textA Gram stain-negative, aerobic, non-motile, short, rod-shaped bacterial strain CAU 1482T was isolated from coal mine wastewater in Hongcheon, Korea. It grew well at 30 °C, pH 8.5, 2% NaCl (w/v). 16S rRNA-based phylogeny indicated that CAU 1482T forms a distinct lineage within Aureimonas with high similarity to Aureimonas frigidaquae CW5T (98.2%), Aureimonas altamirensis S21BT (98.0%), and Aureimonas glaciei B5-2T (96.3%). The predominant cellular fatty acids were C18:1 2-OH, C16:0, C18:1 ω7c, and/or C18:1 ω6c (summed feature 8), with Q-10 as the major isoprenoid quinone. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, two unidentified aminolipids, and three unidentified lipids. The 3.9-Mb genome included 8 contigs and 3599 protein-coding genes with a 56.7 mol% G + C content. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain CAU 1482T and closely related strains of A. frigidaquae CW5T and A. altamirensis S21BT were 72.2？72.4% and 18.7？18.8%, respectively. These phenotypic, chemotaxonomic, and phylogenetic data support CAU 1482T as a novel Aureimonas species, for which the name Aureimonas fodinaquatilis sp. nov. is proposed. The type strain is CAU 1482T (= KCTC 62995T = NBRC 113692T).
Inhibitory effects of decaschistia intermedia craib extract on melanin synthesis
No full textThe purpose of this study was to investigate the anti-melanogenic effects of the extracts from Decaschistia intermedia craib (EDI). In this study, we examined the effects of EDI on mushroom tyrosinase activity in in vitro, melanin contents, and expression levels of mRNA and proteins of melanogenesis-related genes in B16F10 melanoma cells. The treatment of EDI significantly decreased both tyrosinase activity and melanin contents in B16F10 cells with dose-dependent manner. In addition, we found that the expression of mRNA or proteins of melanogenic proteins, such as, a-melanocyte-stimulating hormone (a-MSH)-induced microphthalmia associated transcription factor (MITF), tyrosinase, tyrosinase related protein-1 (TRP-1), and TRP-2 was significantly downregulated with dose-dependent manner in the EDI-treated B16F10 cells compared to controls. Our results suggest that the EDI inhibits cellular melanogenesis through downregulation of a-MSH-stimulated melanin synthesis. Thus EDI may potentially be an effective whitening agent.
The food-grade antimicrobial xanthorrhizol targets the enoyl-ACP reductase (FabI) in Escherichia coli
No full textXanthorrhizol, isolated from the Indonesian Java turmeric Curcuma xanthorrhiza, displays broad-spectrum antibacterial activity. We report herein the evidence that mechanism of action of xanthorrhizol may involve FabI, an enoyl-(ACP) reductase, inhibition. The predicted Y156V substitution in the FabI enzyme promoted xanthorrhizol resistance, while the G93V mutation originally known for triclosan resistance was not effective against xanthorrhizol. Two other mutations, F203L and F203V, conferred FabI enzyme resistance to both xanthorrhizol and triclosan. These results showed that xanthorrhizol is a food-grade antimicrobial compound targeting FabI but with a different mode of binding from triclosan.
Coiled-coil domain containing 50-V2 protein positively regulates neurite outgrowth
No full textThe coiled-coil domain containing 50 (CCDC50) protein is a phosphotyrosine-dependent signalling protein stimulated by epidermal growth factor. It is highly expressed in neuronal cells in the central nervous system; however, the roles of CCDC50 in neuronal development are largely unknown. In this study, we showed that the depletion of CCDC50-V2 impeded the neuronal development process, including arbor formation, spine density development, and axonal outgrowth, in primary neurons. Mechanistic studies revealed that CCDC50-V2 positively regulated the nerve growth factor receptor, while it downregulated the epidermal growth factor receptor pathway. Importantly, JNK/c-Jun activation was found to be induced by the CCDC50-V2 overexpression, in which the interaction between CCDC50-V2 and JNK2 was also observed. Overall, the present study demonstrates a novel mechanism of CCDC50 function in neuronal development and provides new insight into the link between CCDC50 function and the aetiology of neurological disorders.
Anti-Inflammatory activities of an extract of in vitro grown adventitious shoots of Toona sinensis in LPS-treated RAW264.7 and Propionibacterium acnes-treated HaCaT cells
No full textToona sinensis has been traditionally used to treat dysentery, enteritis, flatulence, and itchiness. However, the existence of anti-inflammatory effects of T. sinensis on Propionibacterium acnes-induced skin disease is unknown. In vitro cultures of plant cells and tissues produced under controlled conditions offer a continuous production platform for plant natural products including pigments and anti-inflammatory agents. In this study, we determine the anti-inflammatory activities of an extract of in vitro grown adventitious shoots of T. sinensis on P. acnes, the etiologic agent of skin inflammation. The extract of T. sinensis showed antioxidant and anti-inflammatory activity in LPS-treated RAW264.7 cells. It also had antibacterial activity and anti-inflammatory effects on P. acnes-treated HaCaT cells. In addition, these effects were regulated by suppression of the mitogen-activated protein kinase (MAPK) pathways. These results suggesting the potential application of adventitious shoots of T. sinensis grown with an in vitro proliferation system as a medicine for treating P. acnes-induced inflammatory skin disease.
Evaluation of the acute toxicity of theoredoxin (TRX) transgenic soybean to Daphnia magna
No full textTheoredoxin (TRX) transgenic soybeans were developed using the human Theoredoxin gene under the control of the β-conglycinin promoter with a selection marker, the phosphinothricin acetyltransferase (PAT) gene. This study was done to assess the acute toxicity of a genetically modified (GM) soybean using the fresh water planktonic crustacean Daphnia magna. The acute toxicity effect of the TRX soybean and non-GM soybean (Gwangan) on D. magna was investigated at different concentrations (0, 156, 313, 625, 1,250, 2,500, and 5,000 mg·L-1). The TRX soybean used for the test was confirmed to express the TRX/PAT genes by PCR and enzyme-linked immunosorbent assay (ELISA). D. magna feeding tests showed no significant differences in the cumulative immobility or an abnormal response with either the TRX soybean or non-GM soybean. The feeding study showed a similar abnormal response and cumulative immobility of the D. magna between the TRX soybean and Gwangan treatments. Additionally, the 48 h-EC50 values for the TRX and Gwangan soybeans were 755.6 and 778 mg·L-1, respectively. The soybean NOEC (no observed effect concentration) value for D. magna was suggested to be 156 mg·L-1. These results suggest that there is no significant difference in toxicity to Daphnia magna between the TRX soybean and its non-GM counterpart.
Risk assessment and evaluation of epidermal growth factor (EGF) transgenic soybean: responses of Cyprinus carpio fed on EGF transgenic soybean
No full textThe epidermal growth factor (EGF) transgenic soybean was developed and biosynthesis of human epidermal growth factor (hEGF) in soybean seeds was confirmed. Also, EGF transgenic soybean were found to contain a herbicide resistance selectable marker by introduction of phosphinothricin acetyltransferase (PAT ) gene from the Streptomyces hygroscopicus. For biosafety assessment, the EGF transgenic soybean expressing the EGF biosynthesis gene EGF and herbicide resistant gene PAT was tested to determine effects on survival of Cyprinus carpio, commonly used as a model organism in ecotoxicological studies. C. carpio was fed 100% ground soybean suspension, EGF soybean or non-genetically modified (GM) counterpart soybean (Gwangan). Gene expression of EGF soybean was confirmed by PCR and ELISA to have EGF/PAT. Feeding test showed that no significant differences in cumulative immobility or abnormal response between C. carpio samples fed on EGF soybean and non-GM counterpart soybean. The 48 h-EC50 values of the EGF and non-GM soybean were 1,688 mg·L-1 (95% confidence limits: 1,585 - 1,798 mg·L-1) and 1,575 mg·L-1 (95% confidence limits: 1,433 - 1,731 mg·L-1), respectively. The soybean NOEC (no observed effect concentration) value for C. carpio was suggested to be 625 mg·L-1. We concluded that there was no significant difference in toxicity for non-target organisms (C. carpio) between the EGF soybean and non-GM counterparts.