• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.736-741
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• 2012

In this study, we analyzed the oxidative stress response of wblA ($\underline{w}$hi$\underline{B}$-$\underline{l}$ike gene $\underline{A}$, SCO3579), which was previously shown to be a global antibiotic down-regulator in Streptomyces coelicolor. Ever since a WblA ortholog named WhcA in Corynebacterium glutamicum was found to play a negative role in the oxidative stress response, S. coelicolor wblA has been proposed to have a similar effect. A wblA-deletion mutant exhibited a less sensitive response to oxidative stress induced by diamide present in solid plate culture. Using real-time RT-PCR analysis, we also compared the transcription levels of oxidative stress-related genes, including sodF, sodF2, sodN, trxB, and trxB2, between S. coelicolor wild type and a wblA-deletion mutant in the presence or absence of oxidative stress. Target genes were expressed higher in the wblA-deletion mutant compared with wild type, both in the absence and presence of oxidative stress. Moreover, expression of these target genes in S. coelicolor wild type was stimulated only in the presence of oxidative stress, suggesting that WblA plays a negative role in the oxidative stress response of S. coelicolor, similar to that of C. glutamicum WhcA, through the transcriptional regulation of oxidative stress-related genes.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.979-987
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• 2011

Culture pH change has some important roles in signal transduction and secondary metabolism. We have already reported that acidic pH shock enhanced actinorhodin production in Streptomyces coelicolor. Among many potential governing factors on pH variation, the putative $Na^+/H^+$ antiporter (sha) genes in S. coelicolor have been investigated in this study to elucidate the association of the sha on pH variation and secondary metabolism. Through the transcriptional analysis and overexpression experiments on 8 sha genes, we observed that most of the sha expressions were promoted by pH shock, and in the opposite way the pH changes and actinorhodin production were enhanced by the overexpression of each sha. We also confirmed that sha8 especially has a main role in maintaining cell viability and pH homeostasis through $Na^+$ extrusion, in salt effect experiment under the alkaline medium condition by deleting sha8. Moreover, this gene was observed to have a function of pH recovery after pH variation such as the pH shock, being able to cause the sporulation. However, actinorhodin production was not induced by the only pH recovery. The sha8 gene could confer on the host cell the ability to recover pH to the neutral level after pH variation like a pH drop. Sporulation was closely associated with this pH recovery caused by the action of sha8, whereas actinorhodin production was not due to such pH variation patterns alone.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.70-79
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• 2014

In an attempt to develop a variety of expression vector systems for Corynebacterium glutamicum, six types of promoters, including $P_{tac}$, $P_{sod}$, $P_{sod}$ with a conserved Shine-Dalgarno (SD) sequence from C. glutamicum, $P_{ilvC}$, $P_{ilvC}$ with a conserved SD-1 ($P_{ilvC-M1}$), and $P_{ilvC}$ with a conserved SD-2 ($P_{ilvC-M2}$), were cloned into a modified shuttle vector, pCXM48. According to analysis of promoter strength by quantitative reverse transcription PCR, $P_{sod}$ and $P_{sod-M}$ were superior to tac and ilvC promoters in terms of transcription activity in C. glutamicum. All of the promoters have promoter activities in Escherichia coli, and $P_{sod-M}$ displayed the highest level of transcriptional activity. The protein expression in constructed vectors was evaluated by measuring the fluorescence of green fluorescent protein (GFP) and SDS-PAGE. C. glutamicum harboring plasmids showed GFP fluorescence with an order of activity of $P_{ilvC}$ > $P_{ilvC-M1}$ > $P_{sod}$ > $P_{ilvC-M2}$ > $P_{sod-M}$, whereas all plasmids except pCSP30 with $P_{sod}$ displayed fluorescence activities in E. coli. Of them, the strongest level of GFP was observed in E. coli with $P_{sod-M}$, and this seems to be due to the introduction of the conserved SD sequence in the translational initiation region. These results demonstrate that the expression vectors work well in both C. glutamicum and E. coli for the expression of target proteins. In addition, the vector systems harboring various promoters with different strengths, conserved SD sequences, and multiple cloning sites will provide a comfortable method for cloning and gene expression, and consequently contribute to the metabolic engineering of C. glutamicum.

• IMMUNE NETWORK
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• v.14 no.3
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• pp.138-148
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• 2014

MicroRNAs (miRNAs) are endogenous small RNA molecules best known for their function in post-transcriptional gene regulation. Immunologically, miRNA regulates the differentiation and function of immune cells and its malfunction contributes to the development of various autoimmune diseases including systemic lupus erythematosus (SLE). Over the last decade, accumulating researches provide evidence for the connection between dysregulated miRNA network and autoimmunity. Interruption of miRNA biogenesis machinery contributes to the abnormal T and B cell development and particularly a reduced suppressive function of regulatory T cells, leading to systemic autoimmune diseases. Additionally, multiple factors under autoimmune conditions interfere with miRNA generation via key miRNA processing enzymes, thus further skewing the miRNA expression profile. Indeed, several independent miRNA profiling studies reported significant differences between SLE patients and healthy controls. Despite the lack of a consistent expression pattern on individual dysregulated miRNAs in SLE among these studies, the aberrant expression of distinct groups of miRNAs causes overlapping functional outcomes including perturbed type I interferon signalling cascade, DNA hypomethylation and hyperactivation of T and B cells. The impact of specific miRNA-mediated regulation on function of major immune cells in lupus is also discussed. Although research on the clinical application of miRNAs is still immature, through an integrated approach with advances in next generation sequencing, novel tools in bioinformatics database analysis and new in vitro and in vivo models for functional evaluation, the diagnostic and therapeutic potentials of miRNAs may bring to fruition in the future.

• YAKHAK HOEJI
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• v.54 no.1
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• pp.49-54
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• 2010

SLC6A19 which reported as a neurotransmitter was composed of seven minisatellites. In previous our study, the minisatellites variants of SLC6A19-MS7 showed the susceptibility for hypertension. When this minisatellte sequences were analyzed using the bioinformatic tool, USF1 (upstream transcription factor 1) was found in this region as a putative transcription factor binding site. USF1 is binding with E-boxes which has a consensus sequence of CACGTG. USF1 is a ubiquitously expressed transcription factor and involved in the transcriptional control of many genes including the molecular pathogenesis of cardiovascular disease. Thus, we investigated that the putative functional relationship between the minisatellites variants and susceptibility for myocardial infarction. A case-control study was performed that compared genomic DNA from 400 controls and 225 cases with myocardial infarction. There were no significant differences observed in the overall allelic distribution of minisatellites between controls and cases, which indicates that this polymorphism is not responsible for myocardial infarction susceptibility. Hence, we analyzed the five different minisatellites alleles from this study and characterized 14 different repeats units (Unit1~Unit14). Then, we evaluated the DNA composition, phylogenic tree, and pairwise distances of its repeats. The variability of each repeats differed from 2.33% to 16%. The phylogenic trees for the four SLC6A19-MS7 minisatellites exhibited very different shapes in their braches and distances, and present most common 8 repeats allele was the longest 14 repeats allele. Therefore, this result may help to understand for the evolutional level of the length of minisatellites.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.102-109
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• 2014

Cetaceans (whales, dolphins, and porpoises) are aquatic mammals that experienced drastic changes during the transition from terrestrial to aquatic environment. Morphological changes include streamlined body, alterations in the face, transformation of the forelimbs into flippers, disappearance of the hindlimbs and the acquisition of flukes on the tail. For a prolonged diving, cetaceans acquired hypoxia-resistance by developing various anatomical and physiological changes. However, molecular mechanisms underlying these adaptations are still limited. CREB-binding protein (CREBBP) is a transcriptional co-activator critical for embryonic development, growth control, metabolic homeostasis and responses to hypoxia. Natural selection analysis of five cetacean CREBBPs compared with those from 15 terrestrial relatives revealed strong purifying selection, supporting the importance of its role in mammals. However, prediction for amino acid changes that elicit functional difference of CREBBP identified three cetacean specific changes localized within a region required for interaction with SRCAP and in proximal regions to KIX domain of CREBBP. Mutations in CREBBP or SRCAP are known to cause craniofacial and skeletal defects in human, and KIX domain of CREBBP serves as a docking site for transcription factors including c-Myb, an essential regulator of haematopoiesis. In these respects, our study provides interesting insights into the functional adaptation of cetacean CREBBP for aquatic lifestyle.

• Molecules and Cells
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• v.40 no.3
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• pp.211-221
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• 2017

Transforming growth factor ${\beta}1$ $(TGF{\beta}1)/Smad4$ signaling plays a pivotal role in maintenance of the dynamic balance between bone formation and resorption. The microRNA miR-155 has been reported to exert a significant role in the differentiation of macrophage and dendritic cells. The goal of this study was to determine whether miR-155 regulates osteoclast differentiation through $TGF{\beta}1/Smad4$ signaling. Here, we present that $TGF{\beta}1$ elevated miR-155 levels during osteoclast differentiation through the stimulation of M-CSF and RANKL. Additionally, we found that silencing Smad4 attenuated the upregulation of miR-155 induced by $TGF{\beta}1$. The results of luciferase reporter experiments and ChIP assays demonstrated that $TGF{\beta}1$ promoted the binding of Smad4 to the miR-155 promoter at a site located in 454 bp from the transcription start site in vivo, further verifying that miR-155 is a transcriptional target of the $TGF{\beta}1/Smad4$ pathway. Subsequently, TRAP staining and qRT-PCR analysis revealed that silencing Smad4 impaired the $TGF{\beta}1$-mediated inhibition on osteoclast differentiation. Finally, we found that miR-155 may target SOCS1 and MITF to suppress osteoclast differentiation. Taken together, we provide the first evidence that $TGF{\beta}1/Smad4$ signaling affects osteoclast differentiation by regulation of miR-155 expression and the use of miR-155 as a potential therapeutic target for osteoclast-related diseases shows great promise.

• Journal of Gastric Cancer
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• v.19 no.4
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• pp.460-472
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• 2019

Purpose: Long noncoding RNA 00703 (LINC00703) was found originating from a region downstream of Kruppel-like factor 6 (KLF6) gene, having 2 binding sites for miR-181a. Since KLF6 has been reported as a target of miR-181a in gastric cancer (GC), this study aims to investigate whether LINC00703 regulates the miR-181a/KLF6 axis and plays a functional role in GC pathogenesis. Materials and Methods: GC tissues, cell lines, and nude mice were included in this study. RNA binding protein immunoprecipitation (RIP) and pull-down assays were used to evaluate interaction between LINC00703 and miR-181a. Quantitative real-time polymerase chain reaction and western blot were applied for analysis of gene expression at the transcriptional and protein levels. A nude xenograft mouse model was used to determine LINC00703 function in vivo. Results: We revealed that LINC00703 competitively interacts with miR-181a to regulate KLF6. Overexpression of LINC00703 inhibited cell proliferation, migration/invasion, but promoted apoptosis in vitro, and arrested tumor growth in vivo. LINC00703 expression was found to be decreased in GC tissues, which was positively correlated with KLF6, but negatively with the miR-181a levels. Conclusions: LINC00703 may have an anti-cancer function via modulation of the miR-181a/KLF6 axis. This study also provides a new potential diagnostic marker and therapeutic target for GC treatment.

• Journal of Life Science
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• v.16 no.1
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• pp.76-81
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• 2006

A $\gamma-butyrolactone$ autoregulator receptor has a common activity as DNA-binding transcriptional repressors controlling secondary metabolism and/or morphological differentiation in Streptomyces. A gene (scaR) encoding it was cloned from Streptomyces cravuligerus, a clavulanic acid producer, and was in vitro characterized in a previous report. In this study to clarify the in vivo function of ScaR, a $\gamma-butyrolactone$ autoregulator receptor of Streptomyces clavuligerus, we constructed a scaR-deleted strain by means of homologous recombination. No difference in morphology was found between the wild-type strain and the scaR-disruptant, but the scaR-disruptant showed higher clavulanic acid production. This indicates that the ScaR in S. clavuligerus acts as a negative regulator of the biosynthesis of clavulanic acid, but plays no role in morphological differentiation.

• Journal of Embryo Transfer
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• v.29 no.4
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• pp.351-359
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• 2014

Phasianus colchicus is not only a beautiful bird but also a great value in science and under the threat of endanger. Hence, the aim of this study was to isolate the pheasant male germ cells (mGCs) and then induce them into elongated sperm-like cells in vitro. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the c-kit positive cells and c-kit negative cells examined by flow cytometry analysis (FCA) was 92.87% and 2.57%, respectively. Subsequently, the mGCs were induced for 48h in DMEM/F12 medium supplemented factors such as retinol acid, testosterone and bovine FSH, followed by 5 weeks in culture. We found that some elongated sperm-like cells appeared initially in vitro under inducement of stimulated factors. The elongated sperm-like cells showed in the expression of changed morphology and post-transcriptional marker such as spermatid associated (SPERT), spermatid perinuclear RNA binding protein (STRBP), round spermatid basic protein 1 (RSBN1) and SPER1L. Moreover, in DNA content identified assay, induced cells showed that the 1C DNA population markedly increased in differentiated group but it was not change in undifferentiated group. Successful in vitro differentiation of pheasant testicular germline cells into spermatids appears to offer extremely attractive potential for the conservation of endangered birds and treatment of male infertility.