• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.239-246
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• 2005

In the central nervous system, nitric oxide (NO) is associated with many pathological diseases such as brain ischemia, neurodegeneration and inflammation. The epigallocatechin gallate (EGCG), a major compound of green tea, is recognized as protective substance against neuronal diseases. This study is aimed to investigate the effect of EGCG on NO-induced cell death in PC12 cells. Administration of sodium nitroprusside (SNP), a NO donor, decreased cell viability in a dose- and time-dependent manner and induced genomic DNA fragmentation with cell shrinkage and chromatin condensation. EGCG diminished the decrement of cell viability and the formation of apoptotic morphologenic changes as well as DNA fragmentation by SNP. EGCG played as an antioxidant that attenuated the production of reactive oxygen species (ROS) by SNP. The cells treated with SNP showed downregulation of Bcl-2, but upregulation of Bax. EGCG ameliorated the altered expression of Bcl-2 and Bax by SNP. The release of cytochrome c from mitochondria into cytosol and expression of voltage -dependent anion channel (VDAC)1, a cytochrome c releasing channel in mitochondria, were increased in SNP-treated cells, whereas were attenuated by EGCG. The enhancement of caspase-9, preceding mitochondria-dependent pathway, caspase-8 and death receptor-dependent pathway, as well as caspase-3 activities were suppressed by EGCG. SNP upragulated Fas and Fas-L, which are death receptor assembly, whereas EGCG ameliorated the expression of Fas enhanced by SNP. These results demonstrated that EGCG has a protective effect against SNP-induced apoptosis in PC12 cells, through scavenging ROS and regulating the mitocondria- and death receptor-mediated signal pathway. The present study suggest that EGCG might be a natural neuroprotective substance.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.6
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• pp.783-796
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• 1997

The relaxation induced by stimulation of the inhibitory non-adrenergic, non-cholinergic (iNANC) nerve is mediated by the release of iNANC neurotransmitters such as nitric oxide (NO), vasoactive intestinal peptide (VIP) and adenosine triphosphate (ATP). The mechanisms of NO, VIP or ATP-induced relaxation have been partly determined in previous studies, but the detailed mechanism remains unknown. We tried to identify the nature of iNANC neurotransmitters in the smooth muscle of guinea pig ileum and to determine the mechanism of the inhibitory effect of nitric oxide. We measured the effect of NO-donors VIP and ATP on the intracellular $Ca^{2+}$ concentration$([Ca^{2+}]_i)$, by means of a fluorescence dye(fura 2) and tension simultaneously in the isolated guinea pig ileal smooth muscle. Following are the results obtained. 1. Sodium nitroprusside $(SNP:10^{-5}\;M)$ or S -nitro-N-acetyl-penicillamine $(SNP:10^{-5}\;M)$ decreased resting $[Ca^{2+}]_i$ I and tension of muscle. SNP or SNAP also inhibited rhythmic oscillation of $[Ca^{2+}]_i$ and tension. In 40mM $K^+$ solution or carbachol ($(CCh:10^{-6}\;M)$-induced precontracted muscle, SNP decreased muscle tension. VIP did not change $[Ca^{2+}]_i$ and tension in the resting or precontracted muscle, but ATP increased resting $[Ca^{2+}]_i$ and tension in the resting muscle. 2. 1H-[1,2,4]oxadiazol(4,3-a)quinoxalin-1-one $(ODQ:1\;{\mu}M)$, a specific inhibitor of soluble guanylate cyclase, limited the inhibitory effect of SNP 3. Glibenclamide $(10\;{\mu}M)$, a blocker of $K_{ATP}$ channel, and 4-aminopyridine (4-AP:5 mM), a blocker of delayed rectifier K channel, apamin $(0.1\;{\mu}M)$, a blocker of small conductance $K_{Ca}$ channel had no effect on the inhibitory effect of SNP. Iberiotoxin $(0.1\;{\mu}M)$, a blocker of large conductance $K_{Ca}$ channel, significantly increased the resting $[Ca^{2+}]_i$, and tension, and limited the inhibitory effect of SNP. 4. Nifedipine $(1\;{\mu}M)$ or elimination of external $Ca^{2+}$ decreased not only resting $[Ca^{2+}]_i$ and tension but also oscillation of $[Ca^{2+}]_i$ and tension. Ryanodine $(5\;{\mu}M)$ and cyclopiazonic acid $(10\;{\mu}M)$ decreased oscillation of $[Ca^{2+}]_i$ and tension. 5. SNP decreased $Ca^{2+}$ sensitivity of contractile protein. In conclusion, these results suggest that 1) NO is an inhibitory neurotransmitter in the guinea pig ileum, 2) the inhibitory effect of SNP on the $[Ca^{2+}]_i$ and tension of the muscle is due to a decrease in $[Ca^{2+}]_i$ by activation of the large conductance $K_{Ca}$ channel and a decrease in the sensitivity of contractile elements to $Ca^{2+}$ through activation of G-kinase.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.627-637
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• 2010

The consumption of tomato has greatly increased recently in Korea, and a large number of tomato cultivars are commercially available in the market. However, identification of tomato cultivars by morphological traits is extremely difficult because of the narrow genetic diversity of breeding lines. Therefore, it is necessary to develop molecular markers for cultivar identification in tomato. In this study, we surveyed single nucleotide polymorphism (SNP), and developed SNP marker sets for tomato cultivar identification. SNP markers were developed based on conserved ortholog set II (COSII) and intron-based markers derived from pepper EST sequences, and marker polymorphism was tested using high-resolution melting (HRM) analysis. A total of 628 primer sets was tested, and 417 primer sets amplifying single bands were selected. Of the 417 primer sets, 70 primer sets showing HRM polymorphism among 4 inbred lines were selected. Eleven markers were selected from the 70 primer sets and subjected to cultivar identification analysis. Thirty two commercial tomato cultivars were successfully identified using the marker set.

• Journal of The Korean Association For Science Education
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• v.26 no.3
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• pp.393-405
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• 2006

The purpose of this study was to analyze the effects of Semantic Network Program (SNP) instruction on learning achievement and motivation in high school biology classes. For this study, a SNP was designed by applying the recommendations in regard to student attention and satisfaction factors in Keller's ARCS theory. SNP instruction was conducted with an experimental group and a control group, each consisting of 62 high school biology class student. A pretest-posttest control group design was employed. The pre-test was used to analyze the learning achievement test, learning motivation test, and semantic forming test. For 4 weeks the experiment group was instructed using the developed SNP which centered on Keller's attention and satisfaction factors, and the control group was instructed via teacher-centered lectures based on the textbook. It was found that SNP instruction efficiently increased students' biology learning achievement (p<.001). It was also discovered that SNP instruction was effective in increasing Keller's motivation strategies on attention and satisfaction factors (p<.001). In addition, SNP instruction positively affected students' semantic formation (p<.001) and learning content retention (p>.05) in the heredity unit by aiding students in the area of active multimedia learning. An in depth interview with students in the class using SNP instruction showed that material learned via this method in biology had longer retention of problem-solving methods. Consequently, SNP instruction according to motivation strategies may high school biology teachers with meaningful teaching-learning methods strategies for the unit on heredity.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.167-173
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• 2008

Somatic cells such as oviduct epithelial cell, uterine epithelial cell, cumulus-granulosa cell and buffalo rat river cell has been used to establish an effective culture system for bovine embryos produced in in vitro. But nitric oxide (NO) metabolites secreted from somatic cells were largely arrested the development of bovine in vitro matured/ in vitro fertilized (IVM/IVF) embryos, suggesting that NO was induced the embryonic toxic substance into culture medium. The objective of this study was to investigate whether BOEC co-culture system can ameliorate the NO-mediated oxidative stress in the culture of bovine IVM/IVF embryos. Therefore, we evaluated the developmental rate of bovine IVM/IVF embryos under BOEC co-culture system in the presence or absence of sodium nitroprusside (SNP), as a NO donor, and also detected the expression of growth factor (TGF-$\beta$, EGF and IGFBP) and apoptosis (Caspase-3, Bax and Bcl-2) genes. The supplement of SNP over 5 uM was strongly inhibited blastocyst development of bovine IVM/IVF embryos than in control and 1 uM SNP group (Table 2). The developmental rates beyond morulae stages of bovine IVM/IVF embryos co-cultured with BOEC regardless of SNP supplement (40.4% in 5 uM SNP+ BOEC group and 65.1% in BOEC group) were significantly increased than those of control (35.0%) and SNP single treatment group (23.3%, p<0.05: Table 3). The transcripts of Bax and Caspase-3 genes were detected in all experiment groups (1:Isolated fresh cell (IFC), 2:Primary culture cell (PCC), 3:PCC after using the embryo culture, 4: PCC containing 5 uM SNP and 5: PCC containing 5 uM SNP after using the embryo culture), but Bcl-2 gene was not detected in IFC and PCC (Fig. 1). In the expression of growth factor genes, TGF-$\beta$ gene was found in all experimental groups, and EGF and IGFBP genes were not found in IFC and PCC (Fig. 2). These results indicate that BOEC co-culture system can increase the development beyond morula stages of bovine IVM/IVF embryos, possibly suggesting the alleviation of embryonic toxic substance like nitric oxide.

• Journal of Life Science
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• v.18 no.6
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• pp.770-775
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• 2008

Several studies reported quantitative trait loci (QTL) for meat quality on porcine chromosome 2. For application of the chromosomal information to pig industry through using DNA technology, single nucleotide polymorphism (SNP) markers are developed by comparative re-sequencing of polymerase chain reaction (PCR) products of 13 candidate genes. A total of 34 SNPs were identified in 11 PCR products, an average of one SNP in every 296 bp.PCR restriction fragment length polymorphism (RFLP) assays were developed for 11 SNPs and used to genotype four commercial pig populations in Korea. The SNP markers were used to map candidate genes in QTL and to clarify the relevance of SNP and quantitative traits.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.504-511
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• 2010

Diabetes is a disease that contains a high concentration of glucose in blood and due to defects in either insulin secretion or insulin action. Although the distinctive causes and factors of diabetes have not been clarified, the genetic factors are suggested as a main susceptibility until now. SNP (Single Nucleotide Polymorphism), as the most common genetic variation, has an influence on personal susceptibility for diseases. A nonsynonymous SNP, which changes the amino acid of the protein and its function, is especially important. Therefore, this study hypothesized that there are associations between specific SNPs of the targeted genes. Transcription factor 7-like 2 (TCF7L2) and fat mass and obesity associated (FTO) genes were selected as target genes from the results of genome-wide association and other related research studies. Second, four nonsynonymous SNPs (three in TCF7L2 and one in FTO gene) were selected as target SNPs by using public database of NCBI (National Center for Biotechnology Information). The recruited personnel was classified into three subgroups of diabetes, impaired fasting glucose (IFG) and normal groups. The individual genotypes of each group were analyzed by resequencing. None of genetic variations at four targeted SNP sites was revealed in all samples of this study. However, this study found two new SNPs that were not reported in TCF7L2 gene. One is synonymous SNP, which is heterozygous of C/T and no amino acid change of asparagine/asparagines, was located at c1641 and found in one normal person. Another is nonsynonymous SNP, which is heterozygous of G/A, was located at c1501 and found in two samples. This new discovered nonsynonymous SNP induce the amino acid change from alanine to threonine. Moreover, this new nonsynonymous SNP was found among two persons, one of whom was a diabetes patient and the other one was a person at boundary between IFG and normal, suggesting that this variant might be associated with IFG or diabetes. Even if there is a limitation of sample number for statistical power, this study has an importance due to the discovery of new SNPs. In the future study, a large sample number of diabetes cohort will be needed to investigate the frequency and association with new discovered SNP.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.289-294
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• 2009

Inositol 1,4,5-triphosphate receptor type 1 (IP3R1) is a $Ca^{2+}$ release channel that responds to the second messenger IP3 and that modulates diverse cellular functions such as contraction/excitation, secretion, gene expression and cellular growth. We discovered single nucleotide polymorphisms (SNPs) within IP3R1 gene and analyzed associations between gene polymorphisms and carcass traits in Korean cattle (Hanwoo) in order to develop novel DNA markers at genomic level. Three SNPs were detected at the position of g.1428617A>G, g.1418843C>T and g.1414377C>T with 24 unrelated Hanwoo samples by direct sequencing of the PCR products. We found that genotype of g.1414377C>T SNP was associated with live weight (P<0.05) and carcass weight (P<0.01) using the general linear model of SAS package. These results suggest that polymorphism of IP3R1 gene was associated with weight-related traits in Hanwoo.

• Journal of Life Science
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• v.26 no.1
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• pp.1-7
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• 2016

Fatness is one of the most important economic traits in pigs. The leptin receptor (LEPR) gene may be a potential candidate for the fatness quantitative trait locus (QTL) on porcine chromosome 6, due to its position and physiological role. Thus, this study was carried out to evaluate the associations between structural variants in the LEPR gene and economic traits in pigs. We obtained an approximately 114-kb sequence containing the complete genomic DNA of the porcine LEPR gene, using shotgun sequencing of a bacterial artificial chromosome clone. We report the complete genomic structure of the porcine LEPR gene. Dozens of transcription factor-binding sites were found in the 1.2 kb upstream region from the transcription start point. An association study was performed with 550 Duroc pigs for 24 single-nucleotide polymorphisms (SNPs), including 6 SNPs within exons and 18 SNPs within the putative 5‘ regulatory region of the porcine LEPR gene. Among them, one SNP (−790C/G) was significantly associated with backfat thickness and lean meat percentage, whereas the others, including two SNPs with missense polymorphisms, had no effect on any phenotype. These results suggest that SNP −790C/G may be a useful marker for genetic improvements of fatness and leanness in Duroc pigs.

• The Korean Journal of Mycology
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• v.43 no.4
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• pp.231-238
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• 2015

Genome-wide reanalyzed data of 25 Flammulina strains were compared against the reference genome (KACC42780) to establish a genome-wide single nucleotide polymorphism (SNP). The rate of mapping differences between the strains reflected in the strain variation in its result. Genome-wide SNPs distribution divided into types of homozygous SNP and heterozygous SNP moreover all of the strains demonstrated a wide variation in all of the regions. In the further study of topological relationship between the collected strains, phylogenetic tree was separated into 3 major groups. Group I contained F. velutipes var. related strains of ASI 4062, 4148, 4195. Group 2 contained strains that are different species of ASI 4188 F. elastica, ASI 4190 F. fennae, and ASI 4194 F. rossica. The other 19 strains F. velutipes were classified as a single group. However, further experiment to discriminate its genetic relationship between the white group and brown group did not verify its validity. The inferred tree exhibited a phylogenetic relationship between Korea white fruitbody forming strains of ASI 4210, 4166, 4178 and Japan white fruitbody forming strains of ASI 4209, 4167 confirmed to be genetically closely related.