• Nutrition Research and Practice
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• v.13 no.1
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• pp.58-63
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• 2019

BACKGROUND/OBJECTIVES: Telomeres are located at the chromosomal ends and progressively shortened during each cell cycle. Telomerase, which is regulated by hTERT and c-MYC, maintains telomeric DNA sequences. Especially, telomerase is active in cancer and stem cells to maintain telomere length for replicative immortality. Recently we reported that walnut phenolic extract (WPE) can reduce cell viability in a colon cancer stem cell (CSC) model. We, therefore, investigated the effect of WPE on telomere maintenance in the same model. MATERIALS AND METHODS: $CD133^+CD44^+$ cells from HCT116, a human colon cancer cell line, were sorted by Fluorescence-activated cell sorting (FACS) and treated with WPE at the concentrations of 0, 10, 20, and $40{\mu}g/mL$ for 6 days. Telomere lengths were assessed by quantitative real-time PCR (qRT-PCR) using telomere specific primers and DNA extracted from the cells, which was further adjusted with single-copy gene and reference DNA ($ddC_t$). Telomerase activity was also measured by qRT-PCR after incubating the PCR mixture with cell protein extracts, which was adjusted with reference DNA ($dC_t$). Transcriptions of hTERT and c-MYC were determined using conventional RT-PCR. RESULTS: Telomere length of WPE-treated cells was significantly decreased in a dose-dependent manner ($5.16{\pm}0.13$ at $0{\mu}g/mL$, $4.79{\pm}0.12$ at $10{\mu}g/mL$, $3.24{\pm}0.08$ at $20{\mu}g/mL$ and $3.99{\pm}0.09$ at $40{\mu}g/mL$; P = 0.0276). Telomerase activities concurrently decreased with telomere length ($1.47{\pm}0.04$, $1.09{\pm}0.01$, $0.76{\pm}0.08$, and $0.88{\pm}0.06$; P = 0.0067). There was a positive correlation between telomere length and telomerase activity (r = 0.9090; P < 0.0001). Transcriptions of both hTERT and c-MYC were also significantly decreased in the same manner. CONCLUSION: In the present cell culture model, WPE reduced telomere maintenance, which may provide a mechanistic link to the effect of walnuts on the viability of colon CSCs.

• Molecules and Cells
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• v.25 no.1
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• pp.78-85
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• 2008

In a search for new molecular pathways associated with asthma, we performed an mRNA differential display analysis using total RNA extracted from the tracheal tissues of ovalbumin (OVA)-challenged mice and sham controls. cDNAs corresponding to mRNAs for which expression levels were altered by OVA-challenge were isolate and sequenced. Twenty-eight genes differentially expressed in sham and OVA challenged mice were identified. A GenBank BLAST homology search revealed that they were related to cytoskeleton remodeling, transcription, protein synthesis and modification, energy production, and cell growth and differentiation. Two were selected for further characterization. Up-regulation of both the perinatal skeletal myosin heavy chain (skMHC) and fast skeletal muscle myosin light chain (skMLC) genes was confirmed by RT-PCR of trachea tissue from OVA challenged mice. Overexpression of skMLC protein was observed in the smooth muscle layers of OVA-challenged mice by immunohistochemistry, and the surface areas stained with skMLC antibody increased in the OVA-challenged mice. The overexpression of skMLC in murine asthma may be associated with the changes of bronchial smooth muscle.

• Development and Reproduction
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• v.9 no.1
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• pp.33-41
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• 2005

Identification of differentially expressed genes at blastocyst stage embryos would provide insights into early development and differentiation. Here, we applied a new differential display reverse transcription polymerase chain reaction(DD RT-PCR) technology, called annealing control primers(ACP) system to identify the genes that are specifically or prominently expressed in mouse blastocysts compared to embryonic stem(ES) cells. Using 100 ACPs, 26 clones were perceived as differentially expressed genes in mouse blastocysts. A BLAST search revealed that cloned genes had significant sequence similarities with known genes in the GenBank/EMBL data base. Among them, 15 genes were selected and conformed by RT-PCR. This analysis suggests that the ACP system is a practical method for the identification of stage-specific genes using small numbers of mouse embryos.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.821-826
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• 2007

The aim of the experiment was to detect polymorphisms in the keratin-associated protein 8.2 (KAP8.2) gene to determine associations between the genotype and fibre traits in Chinese Inner Mongolia cashmere goats. The fibre traits data investigated were cashmere fibre diameter, combed cashmere weight, cashmere fibre length and guard hair length. Five hundred and forty-two animals were used to detect polymorphisms in the complete coding sequence of the hircine KAP8.2 gene by means of PCR-SSCP. The results identified six genotypes, AA, BB, DD, AB, AD and BD, coded for by three different alleles A, B and D. Two SNPs in the coding region were confirmed by sequencing, which were A214G and T218C respectively. The relationships between the genotypes and cashmere fibre diameter, combed cashmere weight, cashmere fibre length and guard hair length were analyzed. There were significant differences (p<0.01) between the associations of the different genotypes with cashmere fibre diameter, cashmere weight and hair length. Cashmere length was the only trait that was not associated with the genotypes. The genotype AA (0.73) was found to be predominant in Inner Mongolia cashmere goats and the animals with this genotype had the thinnest cashmere fibre diameter compared with the other genotypes. These results suggested that polymorphisms in the hircine KAP8.2 gene may be a potential molecular marker for cashmere fibre diameter in cashmere goats.

• Molecules and Cells
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• v.24 no.1
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• pp.139-147
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• 2007

Although transforming growth factors (TGFs) are implicated in the process of endochondral ossification, which is initiated by the differentiation of mesenchymal cells into chondrocytes, it is not clear how $TGF-{\beta}3$ regulates the chondrogenic differentiation of limb bud mesenchymal cells. Here, differential display polymerase chain reaction (DD-PCR) screening and RT-PCR analysis revealed that transcripts of A Disintegrin And Metalloprotease 10 (ADAM 10) decreased during the chondro-inhibitory action of $TGF-{\beta}3$ on cultured chick leg bud mesenchymal cells. Electroporation of ADAM 10 morpholino antisense oligonucleotides inhibited the ectodomain shedding of delta-1, and cell proliferation and subsequent precartilage condensation, in a manner similar to that caused by $TGF-{\beta}3$. The suppression of mesenchymal cell proliferation induced by $TGF-{\beta}3$ and ADAM 10 morpholino antisense oligonucleotides was reversed by activation of ADAM 10 with phorbol 12-myristate 13-acetate (PMA) or knockdown of Notch-1 with siRNA. Collectively, these data indicate that, in cultured chick leg bud mesenchyme cells, $TGF-{\beta}3$ downregulates ADAM 10 and inhibits cell proliferation and subsequent precartilage condensation by inhibiting the ectodomain shedding of delta-1, and that this results in the activation of Notch signaling.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.89-96
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• 2016

Tooth development shows dynamic morphological changes from the stages of cap to hard tissue formation and is strictly regulated during development. In the present study, we compared expression and localization of 3 major enamel matrix proteins in rats: amelogenin, enamel and ameloblastin. DD-PCR and RT-PCR revealed differential expression of the major proteins from the cap stage to root stage. Immunofluorescence staining results indicated that amelogenin was not detected in either inner enamel epithelium or reduced enamel epithelium, but highly immunoreactive in preameloblasts and ameloblasts; in addition, it was sporadically expressed in preodontoblasts abutting preameloblasts. Ameloblastin expression was also observed in not only differentiated ameloblasts but also osteoblasts. Immunoreactivity to ameloblastin in ameloblasts was strong in Tomes' processes. Enamelin was exclusively localized along the entire newly formed and maturing enamel. Enamelin was largely localized in near Tomes' processes and enamel rods in maturing enamel. Alendronate treatment resulted in down-regulation of amelogenin and ameloblastin at both transcription and translation levels; whereas, enamelin expression was unchanged in response to the treatment. These results suggested that amelogenin, ameloblastin and enamelin might be implicated in cell differentiation, adhesion of ameloblasts to enamel and enamel crystallization during enamel matrix formation, respectively.

• The Journal of the Korean Society for Microbiology
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• v.35 no.2
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• pp.149-157
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• 2000

Mycobacterium tuberculosis is capable of growing and survival within macrophage. The purpose of this study was to identify the genes regulated by infection of mycobacteria in human monocytic THP-1 cells. We used the differential display reverse transcriptase polymerase chain reaction (DD RT-PCR) and nothern blot analysis to confirm the differentially expressed genes from THP-1 cells infected with live Mycobacterium tuberculosis H37Rv, heat-killed Mycobacterium tuberculosis H37Rv and live Mycobacterium bovis BCG. Among many up or down-regulated clones, 27 clones were sequenced and compared with known genes on GenBank. Thirteen of over-expressed clones from THP-1 cells infected with live Mycobacterium tuberculosis H37Rv were identical to human prothymosin alpha, eight were novel clones and six clones showed homology with Human ferritin H chain, Esherichia coli bgl, Mouse RNA-dependent EIF-2 alpha kinase, E. coli htrL, Hyaluronan receptor and T cell receptor. Our result suggests that Mycobacterium tuberculosis might regulate prothymosin alpha gene transcription in monocytic THP-1 cell.

• Molecules and Cells
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• v.23 no.3
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• pp.287-303
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• 2007

Expressed sequence tags (ESTs) and differentially expressed cDNAs from the self-fertilizing fish, Kryptolebias marmoratus were mined to develop alternative biomarkers for endocrine-disrupting chemicals (EDCs). 1,577 K. marmoratus cDNA clones were randomly sequenced from the 5'-end. These clones corresponded to 1,518 and 1,519 genes in medaka dbEST and zebrafish dbEST, respectively. Of the matched genes, 197 and 115 genes obtained Unigene IDs in medaka dbEST and zebrafish dbEST, respectively. Many of the annotated genes are potential biomarkers for environmental stresses. In a differential display reverse transcriptase-polymerase chain reaction (DD RT-PCR) study, 56 differential expressed genes were obtained from fish liver exposed to bisphenol A. Of these, 16 genes were identified after BLAST search to GenBank, and the annotated genes were mainly involved in catalytic activity and binding. The expression patterns of these 16 genes were validated by real-time RT-PCR of liver tissue from fish exposed to bisphenol A. Our findings suggest that expression of these 16 genes is modulated by endocrine disrupting chemicals, and therefore that they are potential biomarkers for environmental stress including EDCs exposure.

• Journal of Sericultural and Entomological Science
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• v.53 no.1
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• pp.44-49
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• 2015

We characterized tissue specific-expressed genes in the posterior silk gland of Bombyx mori using by the Annealing Control Primer based differential display-PCR manner. In this study, we isolated 34 differentially expressed PCR amplicons, which one of these was identified as a novel transcript named as ACP-16 (366 bp), its expression was observed only in the posterior silk glands by Northern blot analysis. To determine promoter region of the ACP-16, we isolated and analyzed a phage DNA having 1.7 kb-long genome DNA including the open reading flame and 5'- upstream untranslated region of the ACP-16 gene from a genomic DNA library. We have estimated a promoter region of the ACP-16 gene by a web promoter prediction engine, which locates -750 ~ -165 from translation initiation site (ATG, +1). ACP-16 gene is necessary to more studies about critical biological role in order to apply the silkworm's transgenic system.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.968-971
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• 2005

The Melanocortin-4 receptor gene (MC4R) regulates the energy balance and the genetic basis of obesity. A polymorphism in the porcine melanocortin-4 receptor has previously shown to be associated with growth, fat deposition and feed intake. In this study, the polymorphism of the gene was studied in several pig breeds of Duroc, Landrace, Berkshire, and Yorkshire. The results showed that the frequencies of MC4R genotype varied among those breeds. Association analyses were also performed between the MC4R polymorphism and average daily gain, feed conversion ratio, backfat thickness and lean percentage phenotypes. The results strongly support that the MC4R polymorphism can be used DNA marker selection indicator for economically important traits for pig breeding program in Korea.