• Molecules and Cells
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• 제44권12호
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• pp.861-878
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• 2021

The human genome contains many retroviral elements called human endogenous retroviruses (HERVs), resulting from the integration of retroviruses throughout evolution. HERVs once were considered inactive junk because they are not replication-competent, primarily localized in the heterochromatin, and silenced by methylation. But HERVs are now clearly shown to actively regulate gene expression in various physiological and pathological conditions such as developmental processes, immune regulation, cancers, autoimmune diseases, and neurological disorders. Recent studies report that HERVs are activated in patients suffering from coronavirus disease 2019 (COVID-19), the current pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. In this review, we describe internal and external factors that influence HERV activities. We also present evidence showing the gene regulatory activity of HERV LTRs (long terminal repeats) in model organisms such as mice, rats, zebrafish, and invertebrate models of worms and flies. Finally, we discuss several molecular and cellular pathways involving various transcription factors and receptors, through which HERVs affect downstream cellular and physiological events such as epigenetic modifications, calcium influx, protein phosphorylation, and cytokine release. Understanding how HERVs participate in various physiological and pathological processes will help develop a strategy to generate effective therapeutic approaches targeting HERVs.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.754-768
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• 2008

The past decades have seen enormous advances in our understanding of how GH acts. GH is a pituitary-derived polypeptide hormone that has diverse physiological effects including the regulation of bone growth, carbohydrate and lipid metabolism. The effects of GH are mediated directly and indirectly through IGF-I. In addition, GH stimulates the hepatic production of ALS. In postnatal life, IGF-I and -II circulate as 150 kDa ternary complexes consisting of one molecule each of IGFBP-3 or IGFBP-5, IGF-I or IGF-II and ALS. It is now known that ALS increases significantly the half-lives of the IGFs, IGFBP-3 and -5, and therefore is responsible for maintaining a circulating reservoir for each of these proteins.

• BMB Reports
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• 제42권7호
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• pp.421-426
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• 2009

Glucocorticoids regulate multiple physiological processes such as metabolic homeostasis and immune response. Mouse Pon2 (mPon2) acts as an antioxidant to reduce cellular oxidative stress in cells. In this present study, we investigated the transcriptional regulation of mPon2 by glucocorticoids. In the presence of glucocorticoid analogue dexamethasone, the expression of mPon2 mRNA in cells was increased, whereas the expression was inhibited by a transcription inhibitor actinomycin D. Glucocorticoid receptors bound to the putative glucocorticoid response elements located between -593 bp and -575 bp of the mPon2 promoter. Transcriptional activity was completely blocked when the putative element was mutated. Taken together, these results suggest that the expression of the mPon2 gene is directly regulated by glucocorticoid-glucocorticoid receptor complexes.

• Molecules and Cells
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• 제27권1호
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• pp.1-3
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• 2009

Mitotic spindle mediates the segregation of chromosomes in the cell cycle and the proper function of the spindle is crucial to the high fidelity of chromosome segregation and to the stability of the genome. Nucleation of microtubules (MTs) from centrosomes and chromatin represents two well-characterized pathways essential for the assembly of a dynamic spindle in mitosis. Recently, we identified a third MT nucleation pathway, in which existing MTs in the spindle act as a template to promote the nucleation and polymerization of MTs, thereby efficiently amplifying MTs in the spindle. We will review here our current understanding on the molecular mechanism, the physiological function and the cell-cycle regulation of MT amplification.

• Toxicological Research
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• 제31권4호
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• pp.415-420
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• 2015

The purpose of the present study is to investigate the correlations between food intake behavior and job stress level and neuropeptide hormone concentrations. Job strain and food intake behavior were first identified using a self-reported questionnaire, concentrations of neuropeptide hormones (adiponectin, brain derived neurotrophic factor [BDNF], leptin, and ghrelin) were determined, and the correlations were analyzed. In the results, job strain showed significant correlations with adiponectin (odds ratio [OR], 1.220; 95% confidence interval [CI], 1.001~1.498; p < 0.05) and BDNF (OR, 0.793; 95% CI, 0.646~0.974; p < 0.05), and ghrelin exhibited a significant correlation with food intake score (OR, 0.911; 95% CI, 0.842~0.985, p < 0.05). These results suggest that job stress affects food intake regulation by altering the physiological concentrations of neuropeptide hormones as well as emotional status.

• International Journal of Oral Biology
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• 제45권2호
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• pp.64-69
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• 2020

Short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are secondary metabolites produced by anaerobic fermentation of dietary fibers in the intestine. Intestinal SCFAs exert various beneficial effects on intestinal homeostasis, including energy metabolism, autophagy, cell proliferation, immune reaction, and inflammation, whereas contradictory roles of SCFAs in the oral cavity have been reported. Herein, we found that low and high concentrations of SCFAs induce differential regulation of intracellular Ca²⁺ mobilization and expression of pro-inflammatory cytokines, such as interleukin (IL)-6 and IL-8, respectively, in gingival fibroblast cells. Additionally, cell viability was found to be differentially regulated in response to low and high concentrations of SCFAs. These findings demonstrate that the physiological functions of SCFAs in various cellular responses are more likely dependent on their local concentration.

• 대한전기학회논문지
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• 제36권7호
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• pp.514-523
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• 1987

Pole assignment adaptive controller has been suggested for automatic regulation of blood pressure by means of hypertinsive of hypotensive drugs. The relationship between the drug infusion rate and the blood pressure was described by an ARMA model. This adaptive algorithm does not reguire preliminary tests for the purpose of tuning the parameters, and have the capability to adjust automatically to changes in the curculatory state of subject. Experimental results on rabbits showed that stable control are occurred during operation. On the basis of theoretical considerations and experimental results, we expected that adaptive drug infusion system using pole assignment procedure might be effectively applied to the blood pressure control in clinical application.

• 동의생리병리학회지
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• 제28권1호
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• pp.59-62
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• 2014

Glucose uptake plays a pivotal role in maintaining whole body glucose homeostasis in adipocytes and skeletal muscles. In the present study we have shown that Fructus Piperis Longi Extracts (FPLE) can stimulate glucose uptake in OP9 adipocytes. The increasing effects of FPLE on glucose uptake were inhibited by compound C pretreatment, which means that the glucose uptake effects by FPLE were carried out by AMP-activated protein kinase (AMPK) activation. Further studies revealed that FPLE stimulated glucose transport occurs through a mechanism involving extracellular signal-regulated kinase (ERK1/2) activation.

• 동의생리병리학회지
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• 제24권2호
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• pp.242-248
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• 2010

The present study was designed in order to determine whether Lonicerae flos (LF) could mitigate rheumatoid arthritis through inhibition of cyclooxygenase (COX)-2 and matrix metalloproteinase (MMP)-9 by regulation of macrophage migration inhibitory factor (MIF). We found that MIF mRNA expression in synoviocytes stimulated with phorbol-12-myristate-13-acetate dose-dependantly decreased by LF extract treatment (0.4 - 1.0 mg/$m{\ell}$). The distribution of MIF, COX-2 and MMP-9 positive reacted cells in LPS induced arthritis of mice were decreased by LF (45 mg/kg/day) treatment for 28 days. These data likely indicate that LF may act as MIF inhibitor and may be possible to develop useful agent for rheumatoid arthritis.

• 한국식품조리과학회지
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• 제18권1호
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• pp.94-100
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• 2002

The dietary carbohydrates are mainly digested and adsorbed at small intestine. We developed a new food additive as an egg yolk antibody(1gY) against maltase, sucrase and sodium dependent g1ucose cotransporter(SGLT) for the regulation of blood glucose level and weight control. The maltase, sucrase and SGLT were purified from porcine small intestine which is very similar to that of human in physiological characteristics. The purification step contained an ultracentrifugation, ion exchange chromatography and hydrophobic chromatography. The hens were immunized by purified protein and the IgY activities against immunized antigens were determined. This antibody obtained from the immunized hen's egg yolks directly inhibited the activities of maltase and sucrase in vitro. And the IgY delayed and decreased the increment of blood g1ucose level after administration of maltose, sucrose and glucose in rat about 30 to 60%. The results of this study suggest that the IgY inhibiting the carbohydrate digestion could be used as functional food materials for weight control and regulation of blood glucose level in diabetes.