• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.335-356
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• 1997

Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

• 한국발생생물학회지:발생과생식
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• 제21권2호
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• pp.111-120
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• 2017

Equine chorionic gonadotropin (eCG) is a unique molecule that elicits the response characteristics of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in other species. Previous studies from this laboratory had demonstrated that recombinant eCG (rec-eCG) from Chinese hamster ovary (CHO-K1) cells exhibited both FSH- and LH-like activity in rat granulosa and Leydig cells. In this study, we analyzed receptor internalization through rec-eCGs, wild type eCG ($eCG{\beta}/{\alpha}$) and mutant eCG ($eCG{\beta}/{\alpha}{\Delta}56$) with an N-linked oligosaccharide at $Asn^{56}$ of the ${\alpha}-subunit$. Both the rec-eCGs were obtained from CHO-K1 cells. The agonist activation of receptors was analyzed by measuring stimulation time and concentrations of rec-eCGs. Internalization values in the stably selected rat follicle-stimulating hormone receptor (rFSHR) and rat luteinizing/chorionic gonadotropin receptor (rLH/CGR) were highest at 50 min after stimulation with 10 ng of $rec-eCG{\beta}/{\alpha}$. The dose-dependent response was highest when 10 ng of $rec-eCG{\beta}/{\alpha}$ was used. The deglycosylated $eCG{\beta}/{\alpha}{\Delta}56$ mutant did not enhance the agonist-stimulated internalization. We concluded that the state of activation of rFSHR and rLH/CGR could be modulated through agonist-stimulated internalization. Our results suggested that the eLH/CGRs are mostly internalized within 60 min by agonist-stimulation by rec-eCG. We also suggested that the lack of responsiveness of the deglycosylated $eCG{\beta}/{\alpha}{\Delta}56$ was likely because the site of glycosylation played a pivotal role in agonist-stimulated internalization in cells expressing rFSHR and rLH/CGR.

• Experimental and Molecular Medicine
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• 제50권12호
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• pp.1.1-1.14
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• 2018

DNA methylation is a regulatory mechanism in epigenetics that is frequently altered during human carcinogenesis. To detect critical methylation events associated with gastric cancer (GC), we compared three DNA methylomes from gastric mucosa (GM), intestinal metaplasia (IM), and gastric tumor (GT) cells that were microscopically dissected from an intestinal-type early gastric cancer (EGC) using methylated DNA binding domain sequencing (MBD-seq) and reduced representation bisulfite sequencing (RRBS) analysis. In this study, we focused on differentially methylated promoters (DMPs) that could be directly associated with gene expression. We detected 2,761 and 677 DMPs between the GT and GM by MBD-seq and RRBS, respectively, and for a total of 3,035 DMPs. Then, 514 (17%) of all DMPs were detected in the IM genome, which is a precancer of GC, supporting that some DMPs might represent an early event in gastric carcinogenesis. A pathway analysis of all DMPs demonstrated that 59 G protein-coupled receptor (GPCR) genes linked to the hypermethylated DMPs were significantly enriched in a neuroactive ligand-receptor interaction pathway. Furthermore, among the 59 GPCRs, six GI hormone receptor genes (NPY1R, PPYR1, PTGDR, PTGER2, PTGER3, and SSTR2) that play an inhibitory role in the secretion of gastrin or gastric acid were selected and validated as potential biomarkers for the diagnosis or prognosis of GC patients in two cohorts. These data suggest that the loss of function of gastrointestinal (GI) hormone receptors by promoter methylation may lead to gastric carcinogenesis because gastrin and gastric acid have been known to play a role in cell differentiation and carcinogenesis in the GI tract.

• 한국가축번식학회지
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• 제23권4호
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• pp.347-352
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• 1999

1. 유전자 재 조합 호르몬 (eCG IPMSG, hCG 및 hFSH)의 활성체크 및 세포내 signal transduction에 관한 기초연구를 위하여 rat의 융모성 성선자극 호르몬 수용체 (LH/CGR) 및 난포 자극호르몬 수용체 (FSHR)를 이미 보고되어진 염기배열에 의하여 PCR 방법으로 크로닝 하여, human embryonic kidney 유래의 293 세포에 transfection 하여 세포 표면에 LH/CGR와 FSHR를 발현하는 cell lines을 분리하였다. 2. hCG와 FSH의 signal을 전달하는 능력은 hCG와 FSH 또는 eCG의 농도증가에 따라 이들 수용체로 하여금 세포내의 cAMP 분비가 증가함을 알 수 있었다. 즉, transfection 되어진 이들 수용체를 발현하는 수용체의 대부분은 ligand binding 기능올 가지고, cAMP 반응에 의한 생리활성을 분석할 수 있으며, 또한 유전자 재조합당 단백질 호르몬 (eCG, hCG 및 hFSH)의 signal transduction, 구조 및 기능연구에 활용할 수 있다.

• Journal of Ginseng Research
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• 제43권3호
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• pp.442-451
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• 2019

Background: Ginseng has a wide range of beneficial effects on health, such as the mitigation of minor and major inflammatory diseases, cancer, and cardiovascular diseases. There are abundant data regarding the health-enhancing properties of whole ginseng extracts and single ginsenosides; however, no study to date has determined the receptors that mediate the effects of ginseng extracts. In this study, for the first time, we explored whether the antiinflammatory effects of Rg3-enriched red ginseng extract (Rg3-RGE) are mediated by retinoid X receptor ${\alpha}$-peroxisome-proliferating receptor ${\gamma}$ ($RXR{\alpha}-PPAR{\gamma}$) heterodimer nuclear receptors. Methods: Nitric oxide assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay, quantitative reverse transcription polymerase chain reaction, nuclear hormone receptor-binding assay, and molecular docking analyses were used for this study. Results: Rg3-RGE exerted antiinflammatory effects via nuclear receptor heterodimers between $RXR{\alpha}$ and $PPAR{\gamma}$ agonists and antagonists. Conclusion: These findings indicate that Rg3-RGE can be considered a potent antiinflammatory agent, and these effects are likely mediated by the nuclear receptor $RXR{\alpha}-PPAR{\gamma}$ heterodimer.

• 생명과학회지
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• 제15권1호
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• pp.112-117
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• 2005

하천변에 사는 식물들은 침수 저항성을 갖추고 있는데 그중 Ranunculus속이나 Rumex속에 속하는 일부 반수생 식물들에서 볼 수 있는 것처럼, 엽병이 급격한 생장을 일으켜 잎이 수표면에 이르게 함으로써 호흡할 수 있는 조건을 확보하는 현상은 식물체내에 축적된 에틸렌에 의하여 매개되는 현상이다. 침수 조건에서는 식물 조직 내에 에틸렌이 축적되며, 축적된 에틸렌은 옥신 등 다른 식물호르몬에 대한 조직의 감수성을 증가시켜 생장을 촉진한다. 증가된 생장으로 잎이 수표면에 이르게 되면 다시 공기를 접촉하여 호흡할 수 있게 되고, 식물체내에 축적되었던 에틸렌은 대기 중으로 확산하여 나가게 되므로 체내 에틸렌 농도가 감소하여 생장률이 침수 이전 수준으로 되돌아간다. 에틸렌에 의한 옥신의 감수성 증가는 선량 반응 곡선에 비추어 수용체의 친화도 증가가 수반되는 것으로 생각되는데, 아직 옥신 수용체가 밝혀지지 않아 분자생물학적 기작은 연구되어야 할 과제로 남아있다. 최근 옥신 수용체 발견의 가능성이 높아지고 있으며, 따라서 에틸렌에 의한 옥신 수용체의 옥신에 대한 감수성 조절기작을 탐구할 수 있는 길이 열릴 것으로 기대된다.

• 한국환경보건학회지
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• 제50권3호
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• pp.212-220
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• 2024

Background: 2-Ethylhexyl diphenyl phosphate (EHDPP) is widely used as a flame-retardant plasticizer in the production of polyvinyl chloride, adhesives, and food packaging. This chemical has been frequently detected in water, sediment, and indoor environments, and its lipophilicity raises concerns about bioaccumulation. Objectives: In this study, the effects of EHDPP on the development, behavioral changes, and growth hormone (GH) endocrine system of zebrafish larvae were investigated. Methods: Fertilized embryos were exposed to various concentrations (control, solvent control, 0.07, 0.7, 7, 70, and 700 ㎍/L) of EHDPP for 96 h. Developmental toxicity endpoints were observed daily. Behavioral changes under light-dark-light conditions and changes in hormones and genes related to GH/insulin-like growth factors (IGFs) axis were determined. Results: Significant decreases in survival, body length and moving distance were observed in zebrafish larvae exposed to 70 and 700 ㎍/L EHDPP. The concentrations of GH and IGF-1 were significantly decreased in zebrafish larvae exposed to 70 and 700 ㎍/L EHDPP. This change was well supported by changes in the transcription of genes involved in GH, IGF, IGF receptors, and IGF binding proteins. Conclusions: Our observations showed that exposure to 70 and 700 ㎍/L EHDPP could disrupt the feedback circuits of the GH/IGFs axis, ultimately leading to developmental toxicity, hypoactivity, and mortality.

• Toxicological Research
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• 제20권3호
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• pp.251-261
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• 2004

A large number of chemical pollutants including phthalates, alkylphenolic compounds and organochlorine pesticides have the ability to disrupt endocrine function in animals, and alter cog-nitive function. Because hormone mediated events play an important role in central nervous system development and function, the changes in cognitive function seem to be mediated by the endocrine-like action of these chemicals. The present study therefore was designed to investigate effect of bisphenol A (BPA), an endocrine disrupting chemical on neuro-behavial patterns, and expression of estrogen receptors and tyrosine hydroxylase, a limiting enzyme of dopamine synthesis pathway. BPA was treated orally for 3 weeks into 3 week old mice, and then the neuro-behavial patterns (stereo-type behaviors such as jumping rearing and forepaw tremor, climbing behavior, tail flick, rotarod and locomotor activity), and the expression of estrogen receptors and tyrosine hydroxylase were deter-mined every 3 week for 9 weeks. During the treatment of BPA, the food uptake and body weight increase were not significantly changed. BPA resulted in the increased stereotype behaviors (jump-ing, rearing and forepaw tremor) 6 or 9 weeks after treatment. The time response to tail flick and locomotor activity were decreased by the treatment of BPA, whereas the time for rotarod was increased by the treatment of BPA. The expression of estrogen receptor alpha and beta was increased in the brain and pituitary gland. Maximum expression was found in the brain after 9 week of 100 mg/kg BPA treatment and in the pituitary gland after 6 week of 100 mg/kg BPA treatment. Tyrosine hydroxylase was increased in dose and time dependent manners in the brain but no change was found in the pituitary gland. The present data show that exposure of BPA in the young mice could alter expression of estrogen receptors and dopamine synthesis pathway, thereby modulate neuro-behavial patterns (increase of stereotype behaviors but decrease locomotor activity).

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.167-167
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• 2001

Peroxisome proliferator-activated receptors(PPARs) are member of the neuclear hormone receptor superfamiliy of ligand-dependent transcription factors that heterodimerizes with the retinoid X receptor to function as a transcriptional regulator. They are divided into three subtypes(PPAR-$\alpha$, $\beta$ and ${\gamma}$).(omitted)

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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• pp.127-127
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• 2001

There is a concern that chemicals in our environment are affecting human health by disrupting a normal endocrine function. Much of the concern has focused on chemicals that can interact directly with steroid hormone receptors. The ability of certain man-made chemicals to mimic the effects of natural steroid hormones and their potential to disrupt the delicate balance of the endocrine system in animals are of increasing concern. (omitted)