• Development and Reproduction
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• v.14 no.4
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• pp.253-259
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• 2010

DNA methylation is one of the major epigenetic regulations of gene expression. The DNA methylation patterns are dramatically changed during gametogenesis and embryogenesis, and especially, it has been known that embryonic stem cells show a distinct methylation pattern. In this study, we examined the methylation patterns of imprinting genes, H19, Igf2r, and Snrpn, in stem cells induced from fertilized embryo (fES) and somatic cell nuclear transferred embryo (ntES). The methylation pattern of H19 gene in both fES and ntES were similar. However, the methylation patterns of Igf2r and Snrpn in ntES (hypermethylated) were slightly different from fES cells.

• IMMUNE NETWORK
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• v.6 no.3
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• pp.128-137
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• 2006

Background: Apoptosis is a physiologic phenomenon involved in development, elimination of damaged cells, and maintenance of cell homeostasis. Deregulation of apoptosis may cause diseases, such as cancers, immune diseases, and neurodegenerative disorders. The mouse myeloma cell P3-X63-Ag8.653 (v653) is an HGPRT deficient $(HGPRT^-)$ mutant strain. High dependency on de novo transcription and translation of aminopterin induced apoptosis of this cell seems to be an ideal experimental system for searching apoptosis-induced genes. Methods & Results: For searching apoptosis-related genes we carried out GE-array (dot blot), Affymetrix GeneChip analysis, Northern analysis and differential display-PCR techniques. The chip data were analyzed with three different programs. 66 genes were selected through Affymetrix GeneChip analyses. All genes selected were classified into 8 groups according to their known functions. They were Genes of 1) Cell growth/maintenance/death/enzyme, 2) Cell cycle, 3) Chaperone, 4) Cancer/disease-related genes, 5) Mitochondria, 6) Membrane protein/signal transduction, 7) Nuclear protein/nucleic acid binding/transcription binding and 8) Translation factor. Among these groups number of genes were the largest in the genes of cell growth/maintenance/death/enzyme. Expression signals of most of all groups were peaked at 3 hour of apoptosis except genes of Nuclear protein/nucleic acid binding/transcription factor which showed maximum signal at 1 hour. Conclusion: This study showed induction of wide range of proapoptotic factors which accelerate cell death at various stage of cell death. In addition apoptosis studied in this research can be classified as a type 2 which involves cytochrome c and caspase 9 especially in early stages of death. But It also has progressed to type 1 in late stage of the death process.

• Fisheries and Aquatic Sciences
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• v.20 no.7
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• pp.9.1-9.13
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• 2017

Background: Metal-responsive transcription factor-1 (MTF-1) is a key transcriptional regulator playing crucial roles in metal homeostasis and cellular adaptation to diverse oxidative stresses. In order to understand cellular pathways associated with metal regulation and stress responses in Pacific abalone (Haliotis discus hannai), this study was aimed to isolate the genetic determinant of abalone MTF-1 and to examine its expression characteristics under basal and experimentally stimulated conditions. Results: The abalone MTF-1 shared conserved features in zinc-finger DNA binding domain with its orthologs; however, it represented a non-conservative shape in presumed transactivation domain region with the lack of typical motifs for nuclear export signal (NES) and Cys-cluster. Abalone MTF-1 promoter exhibited various transcription factor binding motifs that would be potentially related with metal regulation, stress responses, and development. The highest messenger RNA (mRNA) expression level of MTF-1 was observed in the testes, and MTF-1 transcripts were detected during the entire period of embryonic and early ontogenic developments. Abalone MTF-1 was found to be Cd inducible and highly modulated by heat shock treatment. Conclusion: Abalone MTF-1 possesses a non-consensus structure of activation domains and represents distinct features for its activation mechanism in response to metal overload and heat stress. The activation mechanism of abalone MTF-1 might include both indirect zinc sensing and direct de novo synthesis of transcripts. Taken together, results from this study could be a useful basis for future researches on stress physiology of this abalone species, particularly with regard to heavy metal detoxification and thermal adaptation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.11a
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• pp.99-113
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• 1996

Taurine, a ${\beta}$-amino acid, plays an important role as a neuromodulator and is necessary for the normal development of the brain. Since de novo synthesis of taurine in the brain is minimal and in vivo studies suggest that taurine does not cross the blood-brain barrier, the blood-cerebrospinal fluid (CSF) barrier is likely to play a role in taurine transport between the central nervous system and the systemic circulation. Therefore, we examined in vivo elimination of taurine from the CSF in the rat to characterize in vivo kinetics of elimination for taurine from the CSF is consistent with the in vitro study. Using a stereotaxic device, cannulaes were placed into the lateral ventricle and the cisterna magna of the rat. Radio-labelled taurine and inulin (a marker of CSF flow) were injected into the lateral ventricle, and the concentrations of the labelled compounds in the CSF were monitored for up to 3 hrs in the cisterna magna. The apparent clearance of taurine from CSF was greater than the estimated CSF flow (p<0.005), indicating that there is a clearance process in addition to the CSF flow. Taurine distribution into the choroid plexus was at least 10 fold higher than that found in other brain areas (e.g., cerebellum, olfactory bulb and cortex). When unlabelled taurine was co-administered with radio-labelled taurine, the apparent clearance of the labeled taurine was reduced (p<0.01), suggesting a saturable disposition of taurine from CSF. Distribution of taurine into the choroid plexus, cerebellum, olfactory bulb and cortex was similarly diminished, indicating that the saturable uptake of taurine into these tissues is responsible for the non-linear disposition. A pharmacokinetic model involving first order elimination and saturable distribution described these data adequately. The Michaelis-Menten rate constant estimated from in vivo elimination study is similar to that obtained in the in vitro uptake experiment Collectively, our results demonstrate that taurine is transported in the choroid plexus via a taurine is cleared from the CSF via a saturable process. This process may be functionally relevant to taurine homeostasis in the brain.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1345-1358
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• 2017

The impact of overproduction of a heterologous protein on the metabolic system of host Lactococcus lactis was investigated. The protein expression profiles of L. lactis IL1403 containing two near-identical plasmids that expressed high- and low-level of the green fluorescent protein (GFP) were examined via shotgun proteomics. Analysis of the two strains via high-throughput LC-MS/MS proteomics identified the expression of 294 proteins. The relative amount of each protein in the proteome of both strains was determined by label-free quantification using the spectral counting method. Although expression level of most proteins were similar, several significant alterations in metabolic network were identified in the high GFP-producing strain. These changes include alterations in the pyruvate fermentation pathway, oxidative pentose phosphate pathway, and de novo synthesis pathway for pyrimidine RNA. Expression of enzymes for the synthesis of dTDP-rhamnose and N-acetylglucosamine from glucose was suppressed in the high GFP strain. In addition, enzymes involved in the amino acid synthesis or interconversion pathway were downregulated. The most noticeable changes in the high GFP-producing strain were a 3.4-fold increase in the expression of stress response and chaperone proteins and increase of caseinolytic peptidase family proteins. Characterization of these host expression changes witnessed during overexpression of GFP was might suggested the metabolic requirements and networks that may limit protein expression, and will aid in the future development of lactococcal hosts to produce more heterologous protein.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.6
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• pp.468-473
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• 2005

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. The molecular mechanisms involved in the development and progression of these carcinomas are not well known. Abnormalities of genomic methylation patterns have been attributed a role in carcinogenesis and local de novo methylation at tumor suppressor loci was held to be involved in silencing of tumor suppressor genes. Using Ms APPCR, we previously isolated a hypermethylated fragment corresponded to the 5' end of TPEF gene from primary liver and lung cancer cells. To confirm the inactivation of TPEF gene by hypermethylation in HNSCC, we investigated correlation between methylation pattern and expression of TPEF in 10 HNSCC cell lines. In methylation analysis such as combined-bisulfite restriction analysis(COBRA) and bisulfite sequencing, only RPMI 2650 showed none methylated pattern and another 9 cell lines showed dense methylation. The TPEF gene expression level analysis using RT-PCR showed that these 9 cell lines had not or significantly low expression levels of TPEF as compared with RPMI 2650. In addition, the increase of TPEF reexpression by 5-AzaC as demethylating agent in 9 cell lines also indicated that TPEF expression was regulated by hypermethylation. These results of this study demonstrate that epigenetic silencing of TPEF gene by aberrant methylation could play an important role in HNSCC carcinogenesis.

• Nutrition Research and Practice
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• v.7 no.4
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• pp.294-301
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• 2013

In this study, we examined the hepatic anti-steatosis activity of carnosic acid (CA), a phenolic compound of rosemary (Rosmarinus officinalis) leaves, as well as its possible mechanism of action, in a high-fat diet (HFD)-fed mice model. Mice were fed a HFD, or a HFD supplemented with 0.01% (w/w) CA or 0.02% (w/w) CA, for a period of 12 weeks, after which changes in body weight, blood lipid profiles, and fatty acid mechanism markers were evaluated. The 0.02% (w/w) CA diet resulted in a marked decline in steatosis grade, as well as in homeostasis model assessment of insulin resistance (HOMA-IR) index values, intraperitoneal glucose tolerance test (IGTT) results, body weight gain, liver weight, and blood lipid levels (P < 0.05). The expression level of hepatic lipogenic genes, such as sterol regulating element binding protein-1c (SREBP-1c), liver-fatty acid binding protein (L-FABP), stearoyl-CoA desaturase 1 (SCD1), and fatty acid synthase (FAS), was significantly lower in mice fed 0.01% (w/w) CA and 0.02% (w/w) CA diets than that in the HFD group; on the other hand, the expression level of ${\beta}$-oxidation-related genes, such as peroxisome proliferator-activated receptor ${\alpha}$ (PPAR-${\alpha}$), carnitine palmitoyltransferase 1 (CPT-1), and acyl-CoA oxidase (ACO), was higher in mice fed a 0.02% (w/w) CA diet, than that in the HFD group (P < 0.05). In addition, the hepatic content of palmitic acid (C16:0), palmitoleic acid (C16:1), and oleic acid (C18:1) was significantly lower in mice fed the 0.02% (w/w) CA diet than that in the HFD group (P < 0.05). These results suggest that orally administered CA suppressed HFD-induced hepatic steatosis and fatty liver-related metabolic disorders through decrease of de novo lipogenesis and fatty acid elongation and increase of fatty acid ${\beta}$-oxidation in mice.

• Journal of Genetic Medicine
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• v.16 no.1
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• pp.39-42
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• 2019

KBG syndrome is an autosomal dominant syndrome presenting with macrodontia, distinctive facial features, skeletal anomalies, and neurological problems caused by mutations in the ankyrin repeat domain 11 (ANKRD11) gene. The diagnosis of KBG is difficult in very young infants as the characteristic macrodontia and typical facial features are not obvious. The youngest patient diagnosed to date was almost one year of age. We here describe a 2-month-old Korean boy with distinctive craniofacial features but without any evidence of macrodontia due to his very early age. He also had a congenital megacolon without ganglion cells in the rectum. A de novo deletion of exons 5-9 of the ANKRD11 gene was identified in this patient by exome sequencing and real-time genomic polymerase chain reaction. As ANKRD11 is involved in the development of myenteric plexus, a bowel movement disorder including a congenital megacolon is not surprising in a patient with KBG syndrome and has possibly been overlooked in past cases.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.730-739
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) causes severe infections and poses a global healthcare challenge. The utilization of novel molecules which confer synergistical effects to existing MRSA-directed antibiotics is one of the well-accepted strategies in lieu of de novo development of new antibiotics. Thymol is a key component of the essential oil of plants in the Thymus and Origanum genera. Despite the absence of antimicrobial potency, thymol is known to inhibit MRSA biofilm formation. However, the anti-MRSA activity of thymol analogs is not well characterized. Here, we assessed the antimicrobial activity of several thymol derivatives and found that 4-chloro-2-isopropyl-5-methylphenol (chlorothymol) has antimicrobial activity against MRSA and in addition it also prevents biofilm formation. Chlorothymol inhibited staphyloxanthin production, slowed MRSA motility, and altered bacterial cell density and size. This compound also showed a synergistic antimicrobial activity with oxacillin against highly resistant S. aureus clinical isolates and biofilms associated with these isolates. Our results demonstrate that chlorinated thymol derivatives should be considered as a new lead compound in anti-MRSA therapeutics.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.10-18
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• 2014

Seed oils (triacylglycerols) of plants are used as a source of essential fatty acids and nutrition for human. In addition, triacylglycerols have been used as industrial raw materials and biofuels. Triacylglycerols are mainly accumulated in seeds by complicated biochemical pathways. Fatty acids are synthesized in the plastids and transported into the endoplasmic reticulum for synthesizing triacylglycerols. It is known for a long time that biosynthesis of triacylglycerols is performed by a de novo synthesis, the Kennedy pathway. However recent studies have revealed that phosphatidylcholine, a major component of cell membrane, plays a central role for triacylglycerols biosynthesis. Phosphatidylcholine is a key regulator determining the relative proportions of unsaturated fatty acids in seeds. It may be a major carrier for the fluxes of fatty acids from the plastid to the endoplasmic reticulum. This finding further suggests that studies of the functions of enzymes involved in the fluxes of fatty acids from phosphatidylcholine to triacylglycerols elucidate the specialized subdomains in the endoplasmic reticulum for triacylglycerols biosynthesis.