• KSBB Journal
• /
• v.9 no.3
• /
• pp.339-345
• /
• 1994

Deletions between UASG and the GALI TATA box reduced glucose repression and allowed constitutive expression of the gene product in the absence of galactose. The relative inducer level (ratio of galactose/glucose concentrations) affected the extent of gene expression and glucose repression. Glucose repression was reduced by a factor of 2 to 5 as the relative inducer level increased. In the medium containing galactose only, induction of ${\beta}$-galactosidase synthesis by galactose increased with plasmid copy number. On the contrary, plasmid copy number did not affect significantly ${\beta}$-galactosidase synthesis in the medium containing both glucose and galactose (2% glucose＋2% galactose), which might be due to glucose repression caused by high glucose concentration. However, when the medium contained the relatively high inducer level (0.4% glucose＋0.8% galactose), ${\beta}$-galactosidase synthesis increased with plasmid copy number, indicating that the beneficial effect of higher galactose concentration was weaker than the repressive effect of higher glucose concentration.

• Journal of Life Science
• /
• v.20 no.5
• /
• pp.670-675
• /
• 2010

Autoimmune regulator gene (Aire) is expressed in the thymus and controls the expression of peripheral self-antigens, known as promiscuous genes. Aire and promiscuous genes are involved in T cell tolerance and autoimmunity in the thymus. Here, we identified Aire-expressing fibroblastic reticular cell (FRC), which was derived from mouse lymph node and also expressed in insulin promiscuous antigen. The expression of insulin was increased in cultured FRC over-expressed with Aire. These data suggest that Aire regulates promiscuous gene expression in FRC, and that this function might be under peripheral selection control.

• Korean Journal of Environmental Biology
• /
• v.22 no.3
• /
• pp.472-477
• /
• 2004

To study the radiation related gene expression in mutants of Bacillus lentimorbus WJ5 induced by gamm radiation, the simultaneous gene expression was analyzed by DNA micro array. We constructed DNA chips including two thousand randomly digested genome spots of B. lentimorbus WJ5 and compared its quantitative aspect with seven mutants induced by gamma radiation $(^{60}/Co)$. From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in all mutants. Especially, genes involved in repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the induction of the direct and/or indirect repair related genes in mutants induced by gamma radiation could be remarkably different from the adaptive responses against acute exposure to radiation.

• Korean Journal of Microbiology
• /
• v.54 no.1
• /
• pp.1-8
• /
• 2018

A prokaryotic cell has various histone-like proteins also known as nucleoid-associated proteins (NAPs). These proteins bind AT-rich sequence at DNA, which induce DNA wrapping, bending, and bridging, and subsequently regulate the gene expression in bacteria. Because NAPs function in transcriptional silencing of virulence genes, it is important to study their roles in gene silencing and specific mechanisms of these proteins. In this review, we discussed two well-known NAPs, H-NS, and HU, and summarized their roles for gene expression in Escherichia coli and Salmonella Typhimurium. Through the oligomerization and filamentation of H-NS, it represses the expression of virulence genes in human pathogenic bacteria, such as Salmonella Typhimurium, and it works with other NAPs positively or negatively. Recently, H-NS also regulates typhoid toxin expression, which causes typhoid fever and systemic disease in human. Additionally, HU regulates the expression of genes related to both virulence and physiology of Salmonella. Therefore, we suggest that NAPs like H-NS and HU are crucial factors to reveal the molecular mechanisms of virulence gene expression in bacteria.

• KSBB Journal
• /
• v.23 no.3
• /
• pp.205-212
• /
• 2008

The efficient soluble expression of human epidermal growth factor (hEGF) was achieved by using functional fusion partners in cytoplasm and periplasm of Escherichia coli (E. coli). hEGF was over-expressed in inactive inclusion body form in cytoplasm of E. coli due to improper disulfide bond formation and hydrophobic interaction, yielding about 5.9 mg/L in flask culture. Six functional fusion partners were introduced by linking to N-terminal part of hEGF gene for the high-level expression of soluble and active hEGF in cytoplasm and peri plasm region. Three fusion partners for cytoplasmic expression such as acidic tail of synuclein (ATS), thioredoxin (Trx) and lipase, and three fusion partners for periplasmic expression such as periplasmic cystein oxidoreductases (DsbA and DsbC) and maltose binding protein (MBP) were investigated. hEGF fused with ATS and DsbA showed over 90% of solubility in cytoplasm and periplasm, respectively. Especially DsbA was found to be an efficient fusion partner for soluble and high-level expression of hEGF, yielding about 18.1 mg/L and three-fold higher level compared to that of insoluble non-fusion hEGF in cytoplasm. Thus, heterologous proteins containing complex disulfide bond and many hydrophobic amino acids can effectively be produced as an active form in E. coli by introducing a suitable peptide or protein.

• Development and Reproduction
• /
• v.15 no.4
• /
• pp.349-357
• /
• 2011

Since nesfatin-1/NUCB2 involved in the control of appetite and energy metabolism was discovered for the first time in hypothalamus, many reports have shown its expression in various tissues. We also recently demonstrated that nesfatin-1/NUCB2 was expressed in the reproductive organs of mouse. However, no data exist on nesfatin-1/NUCB2 expression, regulation, and secretion in the uterus. Therefore, we examined the expression of nesfatin-1/NUCB2 in mouse uterus and the effects of PMSG and estrogen on its expression. NUCB2 mRNA expression in the uterus was determined by conventional and real-time PCR and nesfatin-1 protein expression was detected by western blotting. In immunohistochemistry staining, nesfatin-1 protein was localized at the epithelial cells of the uterine glands and endometrium. Nesfatin-1 protein binding sites were displayed at the epithelial cells of uterine glands and specific granulocytes including neutrophils. Additionally, to examine if the nesfatin-1/NUCB2 expression in the uterus is regulated by gonadotropin or estrogen, ovariectomized mice were treated with PMSG or $17{\beta}$-estradiol. The expression levels of NUCB2 mRNA in the uterus was significantly increased in the control mice after PMSG treatment, but not in the ovariectomized mice. In contrast, NUCB2 mRNA expression was dramatically increased in the ovariectomized mice after treatment with $17{\beta}$-estradiol. We report here for the first time that nesfatin-1/NUCB2 mRNA and protein express in the mouse uterus and its expression is regulated by estrogen secreted from the ovary, but not gonadotropin from the pituitary.

• Clinical and Experimental Pediatrics
• /
• v.51 no.10
• /
• pp.1096-1101
• /
• 2008

Purpose : Patients with chronic granulomatous disease (CGD) have genetic mutations in a component of the NADPH oxidase enzyme that is necessary for the generation of the superoxide anion. The profound defect in innate immunity is reflected by the patients susceptibility to catalase-positive bacteria and fungi. In addition, CGD patients display signs of persistent inflammation, which is not associated only with deficient superoxide anion production. The aim of this study was to elucidate the cytokine responses in CGD patients after $TNF-{\alpha}$ stimulation. Methods : Heparinized blood samples were collected from 8 CGD patients and 10 healthy volunteers. Monocytes ($1{\times}10^6cell/well$) isolated by the magnet cell isolation system were incubated with a constant amount of $TNF-{\alpha}$ (10 ng/mL) at $37^{\circ}C$ for 6 h. Incubated cells were harvested at 60-min intervals for IL-8 and IL-10 mRNA analysis, and the supernatant was collected at the same intervals to determine IL-8 and IL-10 expression. Monocytes from healthy volunteers were also incubated with antioxidants followed by $TNF-{\alpha}$ stimulation for IL-8 and IL-10 expression. Results : In CGD patients, a high expression of IL-8 together with a significantly higher IL-10 expression than in the healthy controls was seen after $TNF-{\alpha}$ stimulation. Moreover, normal monocytes treated with antioxidants exhibited increased IL-8 responses. Conclusion : The absence of phagocyte-derived reactive oxidants in CGD might be associated with a dysregulated production of pro- and antiinflammatory cytokines. Additional research related to reactive oxidants is needed to clarify the role of cytokines in CGD patients.

• Development and Reproduction
• /
• v.8 no.1
• /
• pp.57-64
• /
• 2004

This study was carried out to examine the expression of the circadian clock genes in the mouse ovary and testis at different developmental stages. Expression of Period1(Per 1), Period2(Per2), Period3(Per3), Cryptochrome1(Cry1), Cyptochrome2(Cry2), Clock Small and Prokineticin1 and Prokineticin2 receptor(Prok1r, Prok2r) genes in mouse ovary was explored by semiquantitative reverse transcription Polymerase chain reaction(RT-PCR) according to the developmental stage(post partum day; ppd 1, 7, 10, 21 and 35). Immunohistochemistry using PER1 antibody was also analyzed. The differential expression pattern of clock genes was presented according to stages of the mouse ovarian development (ppd 1, 7, 10, 21 and 35). In the cases of ovaries, at the starting point of follicle growth at ppd 7 and 10, the clock gene expression patterns were changed vastly. According to the developmental stages, the clock genes were highly expressed at ppd 7 and 10 in mouse testis also. Receptors for Prok2, the circadian output molecule of SCN, were also expressed in ovary at ppd 7 and in testis at ppd 1 and 7, respectively. Immnunohistochemical analysis of PER1 showed positive signals in the cytoplasm of oocytes and granulosa cells. The level or PER1 expression was increased in cells at the spermatogonia and the condensing spermatids. The expression pattern of Perl and localization of PER1 were showed similar patterns according to the developmental stages in ovary and testis. Taken together, it could be observed that the expression of clock genes was highly correlated with gonadal development and germ cell differentiation in mice. Therefore, in this study, circadian programming of the genes in the ovary and testis is strongly imposed across a wide range of core reproductive cycles and normal development of gametes. Although the existence of circadian genes is clearly investigated, further studies on the direct evidence is required for the understanding of the relationship between circadian genes and regulation of gonadal differentiation and germ cell development.

• Clinical and Experimental Pediatrics
• /
• v.48 no.7
• /
• pp.779-788
• /
• 2005

Purpose : Echinacea, a traditional plant medicine has been used as immune-stimulant. Recent studies have revealed that extract of Echinacea has immunostimulatory effects on human blood mononuclear cells. This study was designed for the purpose of screening the genes associated with immunologic effects of Echinacea on monocytes and dendritic cells using a cDNA microarray chip. Methods : $CD14^+$ monocyte cells were cultured for one day with Echinacea extract(final concentration : $50{\mu}g/mL$) in experiment 1, but were cultured without Echinacea in experiment 2. The gene expression of these cultured monocytes was analyzed using the cDNA microarray chip. Dendritic cells produced from $CD14^+$ monocyte were cultured for five days with GM-CSF and IL-4, and then cultured for one day with Echinacea in experiment 3, but were done without Echinacea in experiment 4. Results : In experiments 1 and 2, there were 17 significantly expressed genes with average expression ratios above 2.5, including interferon gamma-inducible protein 30(IFI 30), CDC(cell-division-cylcle)-like kinase 2(CLK 2), syndecan binding protein(syntenin), superoxide dismutase 2, etc. In experiments 3 and 4, there were 24 gene, with significantly expressed genes were 24 genes, which were insulin-like growth factor 2(somatomedin A), methyl-CpG binding domain protein 3, IFI 30, small inducible cytokine subfamily A, member 22, etc. The genes encoding CD44, IFI 30, mannose receptor C type 1(MRC 1), chemokine receptor 7(CCR 7), CLK 2, syntenin and cytochrome C oxidase subunit VIII were significantly expressed in both monocytes and dendritic cells cultured with Echinacea. Conclusion : This study employed a cDNA microarray chip to elicit the immune-associated gene profile; the expression was enhanced by Echinacea in CD14+ monocytes and dendritic cells. Thus we laid the basis for the quantitative and functional analysis of genes induced by Echinacea in monocytes and monocyte-derived dendritic cells.

• The Journal of the Korean bone and joint tumor society
• /
• v.9 no.2
• /
• pp.178-189
• /
• 2003

Purpose: The current study was designed to investigate the expression pattern of chemokine in musculoskeletal tumors, and between primary osteosarcoma and recurred, and postchemotherapy one. Materials and methods: Ten primary soft tissue and bone tumors, one primary, one recurred, one post-chemotherapy osteosarcoma, and one normal control patients were included in the current study. RT-PCR and RPA were used for the investigation of the expression of cytokines and chemokines. Fisher's exact test in SPSS was used for the statistical analysis. Results: IL-8 and TNF-${\alpha}$ were expressed in all tumor tissues, IFN-${\gamma}$ was in all except two cases, RANTES was in 5 soft tissue tumors and 4 bone tumors, GRO-${\alpha}$was in one soft tissue tumor and 2 bone tumors, and MCP-1 and IP-10 were in two bone tumors and in all the other group. In recurred osteosarcoma all the cytokines and chemokines were expressed, and the degree of the expression was stronger than the primary, except IFN-${\gamma}$. After chemotherapy, RANTES, IFN-${\beta}$ and TGF${\beta}_1$ among the TGF${\beta}$isoforms were expressed. Conclusion: There were differences in the expression of cytokines and chemokines in some different bone and soft tissue tumors, even though it was impossible to support this statistically due to small numbers of cases. The expression pattern of IFN-${\gamma}$and TGF-${\beta}$ isoform in osteosarcoma could be used for the study of tumor recurrence and the changes after chemotherapy.