• Nutritional Sciences
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• v.6 no.2
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• pp.73-77
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• 2003

PAI-1 (plasminogen activator inhibitor-1), leptin, and resistin are synthesized and secreted by Int cells of rodents and have recently been postulated to be an important link to obesity. This study was conducted to identify the nutritional regulation of PAI-1, leptin, and resistin gene expression in 0b/ob mice. The mice were divided into four groups according to nutritional status: control, 48 hour fasting, 48 hour-fasting/12 hour-refeeding, and 48 hour-fasting/24 hour-refeeding. The mRNA levels of each peptide were measured by semi-quantitative RT-PCR. In visceral fat tissue, the level of PAI-1 mRNA increased markedly when 48h-fasted animals were refed with a high carbohydrate-low fat diet. However, lasting/refeeding did not appreciably change PAI-1 mRNA levels in subcutaneous fat tissue. Similar results were obtained for resistin mRNA levels in both types of fat tissues. These findings suggest that visceral adipose tissue might be more sensitively involved in the nutritional regulation of PAI-1 and resistin gene expression compared to subcutaneous fat tissue. The level of leptin mRNA decreased markedly in the 48h-fasted animals, and increased markedly when 48h-fasted animals were refed with a high carbohydrate-low fat diet. The nutritional regulation of leptin mRNA showed similar patterns in both types of fat tissues. In conclusion, the nutritional regulation of gene expression encoding PAI-1, resistin, and leptin from adipocytes may vary according to the type of adipose tissue.

• Genomics & Informatics
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• v.15 no.4
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• pp.170-177
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• 2017

HOTAIR is an lncRNA that has been known to have an oncogenic role in different cancers. There is limited knowledge of genetic and epigenetic elements and their interactions for the gene encoding HOTAIR. Therefore, understanding the molecular mechanism and its regulation remains to be challenging. We used different in silico analyses to find genetic and epigenetic elements of HOTAIR gene to gain insight into its regulation. We reported different regulatory elements including canonical promoters, transcription start sites, CpGIs as well as epigenetic marks that are potentially involved in the regulation of HOTAIR gene expression. We identified repeat sequences and single nucleotide polymorphisms that are located within or next to the CpGIs of HOTAIR. Our analyses may help to find potential interactions between genetic and epigenetic elements of HOTAIR gene in the human tissues and show opportunities and limitations for researches on HOTAIR gene in future studies.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.473-477
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• 1993

Both glycerol-phosphate acyltransferase (GPAT) and 7.2 kb mRNAs were present at the highest level in liver. Glycerol-phosphate acyltransferase and 7.2 kb mRNA levels increased dramatically when fasted mice were refed a high carbohydrate diet. In mature 3T3-L1 adipocytes, insulin increased both glycerol-phosphate acyltransferase and 7.2kb mRNA levels 2.6 to 3-fold while dibutyryl cAMP decreased mRNA levels by 50% and 80%, respectively. These results indicate positive regulation by insulin and negative regulation by dibutyryl cAMP of both glycerol-phosphate acyltransferase and 7.2 kb mRNA.

• Genomics & Informatics
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• v.3 no.2
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• pp.66-72
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• 2005

The epidermis is a physiological barrier to protect organisms against environment. During the aging process, skin tissues undergo various changes including morphological and functional changes. The transcriptional regulation of genes is part of cellular reaction of aging process. In order to examine the changes of gene expression during the aging process, we used the primary cell culture system of human keratinocytes. Since UV radiation is the most important environmental skin aggressor, causing skin cancer and other problems including premature skin aging, we examined the changes of gene expression in human keratinocytes after UV irradiation using oligonucleotide microarray containing over 10,000 genes. We also compared the gene expression patterns of the senescent and UV treated cells. Expression of the variety of genes related to transcription factors, cell cycle regulation, immune response was altered in human keratinocytes. Some of down-regulated genes are represented in both senescent and UV treated cells. The results may provide a new view of gene expression following UVB exposure and aging process in human keratinocytes.

• Natural Product Sciences
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• v.10 no.5
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• pp.197-206
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• 2004

Cytochrome P4501A2 (CYP1A2) is responsible for the metabolic activation of a number of aromatic amines and amides to mutagenic and carcinogenic moieties. Considerable variations in the level of CYP1A2 expression in humans have been reported. Thus, the level of human CYP1A2 may determine an individuals susceptibility to these chemicals. Given its importance, the molecular mechanisms of CYP1A2 regulation have been studied by many groups. Direct interactions between transcription factors with the promoters of the gene represent one of the primary means by which the expression of CYP1A2 is controlled. In this review, several important cis elements, transcription factors and the effects of deacetylation/methylation of promoter regions that play an important role in the induction by PAHs as well as constitutive expression of human CYP1A2 are discussed.

• Journal of Microbiology
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• v.39 no.1
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• pp.42-48
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• 2001

The regulation of actin gene expression during the differentiation of Naegleria gruberi was examined. Actin mRNA concentration was maximal in amoebae and decreased rapidly after the initiation of differentiation. At 20 min after initiation, the concentration of actin mRNA decreased to 55% of the maximal value. The actin mRNA concentration decreased to the minimum at 80 min (15% of the maximum), and then began to increase slightly at the end of differentiation. This decrease of actin mRNA concentration was regulated by the repression of actin gene transcription based on nuclear run-on transcription experiments. The rates of transcription of actin gene in nuclei prepared at 40 and 80 min after the initiation of differentiation were 50 and 28% of that of nuclei prepared at the beginning of differentiation, respectively. The addition of cycloheximide at the initiation of differentiation inhibited both the rapid decrease in the concentration of actin mRNA and the repression of actin gene transcription. These results suggest that the rapid decrease in the concentration of actin mRNA during the differentiation of N. gruberi is accomplished by the repression of actin gene transcription and this transcriptional regulation requires continuous protein synthesis during the differentiation.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3681-3685
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• 2012

Background: In breast cancer, estrogen receptors have been demonstrated to interact with transcription factors to regulate target gene expression. However, high-throughput identification of the transcription regulation relationship between transcription factors and their target genes in response to estradiol is still in its infancy. Purpose: Thus, the objective of our study was to interpret the transcription regulation network of MCF7 breast cancer cells exposed to estradiol. Methods: In this work, GSE11352 microarray data were used to identify differentially expressed genes (DEGs). Results: Our results showed that the MYB (v-myb myeloblastosis viral oncogene homolog [avian]), PGR (progesterone receptor), and MYC (v-myc myelocytomatosis viral oncogene homolog [avian]) were hub nodes in our transcriptome network, which may interact with ER and, in turn, regulate target gene expression. MYB can up-regulate MCM3 (minichromosome maintenance 3) and MCM7 expression; PGR can suppress BCL2 (B-cell lymphoma 2) expression; MYC can inhibit TGFB2 (transforming growth factor, beta 2) expression. These genes are associated with breast cancer progression via cell cycling and the $TGF{\beta}$ signaling pathway. Conclusion: Analysis of transcriptional regulation may provide a better understanding of molecular mechanisms and clues to potential therapeutic targets in the treatment of breast cancer.

• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1692-1700
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• 2017

Ralstonia solanacearum causes bacterial wilt in a wide variety of host plant species and produces a melanin-like blackish-brown pigment in stationary phase when grown in minimal medium supplemented with tyrosine. To study melanin production regulation in R. solanacearum, five mutants exhibiting overproduction of melanin-like pigments were selected from a transposon (Tn) insertion mutant library of R. solanacearum SL341. Most of the mutants, except one (SL341T), were not complemented by the original gene or overproduced melanins. SL341T showed Tn insertion in a gene containing a conserved domain of eukaryotic transcription factor. The gene was annotated as a hypothetical protein, given its weak similarity to any known proteins. Upon complementation with its original gene, the mutant strains reverted to their wild-type phenotype. SL341T produced 3-folds more melanin at 72 h post-incubation compared with wild-type SL341 when grown in minimal medium supplemented with tyrosine. The chemical analysis of SL341T cultural filtrate revealed the accumulation of a higher amount of homogentisate, a major precursor of pyomelanin, and a lower amount of dihydroxyphenylalanine, an intermediate of eumelanin, compared with SL341. The expression study showed a relatively higher expression of hppD (encoding hydroxyphenylpyruvate dioxygenase) and lower expression of hmgA (encoding homogentisate dioxygenase) and nagL (encoding maleylacetoacetate isomerase) in SL341T than in SL341. SL341 showed a significantly higher expression of tyrosinase gene compared with SL341T at 48 h post-incubation. These results indicated that R. solanacearum produced both pyomelanin and eumelanin, and the novel hypothetical protein is involved in the negative regulation of melanin production.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.406-411
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• 2011

Background: Invariant Natural killer T (iNKT) cells, a distinct subset of CD1d-restricted T cells with invariant $V{\alpha}{\beta}$ TCR, functionally bridge innate and adaptive immunity. While iNKT cells share features with conventional T cells in some functional aspects, they simultaneously produce large amount of Th1 and Th2 cytokines upon T-cell receptor (TCR) ligation. However, gene expression pattern in two types of cells has not been well characterized. Methods: we performed comparative microarray analyses of gene expression in murine iNKT cells and conventional $CD4^+CD25^-$ ${\gamma}{\delta}TCR^-$ T cells by using Gene Set Enrichment Analysis (GSEA) method. Results: Here, we describe profound differences in gene expression pattern between iNKT cells and conventional $CD4^+CD25^-$ ${\gamma}{\delta}TCR^-$ T cells. Conclusion: Our results provide new insights into the functional competence of iNKT cells and a better understanding of their various roles during immune responses.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.275-281
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• 2009

Modification of thyroid hormone levels has a profound effect on skeletal muscle differentiation, predominantly through direct regulation involving thyroid hormone receptors. Nevertheless, little is known about the regulation of myostatin gene expression in skeletal muscle due to altered concentrations of thyroid hormone. Thus, the goal of our study was to find out whether altered thyroid states could change the gene expression of myostatin, the most powerful inhibitor of skeletal muscle development. A hyperthyroid state was induced in rats by daily injections of L-thyroxine 20 mg/100 g body weight for 14 days, while a hypothyroid state was induced in another group of rats by administering methimazole (0.04%) in drinking water for 14 days. After a period of 14 days of L-thyroxine treatment we observed a significant increase of myostatin expression both in mRNA and protein level. However, decreased expression of myostatin mRNA and protein were observed in hypothyroid rats. Furthermore, our studies demonstrated that the upregulation of myostatin gene expression might be responsible for the loss of body weight induced by altered thyroid hormone levels. We concluded that myostatin played a role in a metabolic process in muscle that was regulated by thyroid hormone.