• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.169-175
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• 2000

The filamentous soil bacterium Streptomyces coelicolor is known to produce four distinct antibiotics. The simultaneous global regulation for the biosynthesis of those four antibiotics was previously confirmed by absA and absB mutations that blocked all four antibiotics' biosynthesis without influencing their morphological differentiation. To study the complex regulatory cascade that controls the secondary metabolism in Streptomyces, a new abs-like mutation was characterized. namely absR, which is slightly leaky on a complete R2YE medium, yet tight on a minimal medium. A genetic analysis of the absR locus indicated that it is located at 10 o'clock on the genetic map, near the site of absA. A cloned copy of the absA gene that encoded bacterial two-component regulatory kinases did not restore antibiotic biosyntheis to the absR mutant. Accordingly, it is proposed that absR is another abs-type mutation which is less tight than the previously identified absA or absB mutations income medium conditions, and can be used to characterize another global regulatory gene for secondary metabolete formation in S. coelicolor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.958-962
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• 1999

Hydroxy methylglutaryl CoA(HMG CoA) reductase and acyl CoA:cholesterol acyltransferase(ACAT) are two important enzymes that are associated with regulation of cholesterol metabolism. The inhibitors of HMG CoA reductase and ACAT are very effective in lowering serum cholesterol in most animal species. In present study, various plant extracts with hot water were used to examine the inhibitory activities against HMG CoA reductase and ACAT that are involved in cholesterol biosynthesis and cholesterol esterification in tissues, respectively. The extracts of Fagophyrum rotundatum, Rosa multiflora, Rosa rugosa and Alisma orientalis exhibited significant inhibitory activities against the ACAT, 29%, 24%, 19%, and 18%, respectively. However the extracts of Typha augustifolia, Polygonum cuspidatum, Crataegus pinnatifida, Polygonum multiflorum inhibited the HMG CoA reductase activity by 53%, 42%, 37%, and 33% respectively. Results suggest that these plant extracts might play important roles in the regulation of the cholesterol metabolism in vivo.

• Natural Product Sciences
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• v.25 no.2
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• pp.165-171
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• 2019

Although the functions of a standardized extract of Gingko biloba leaves (EGb $761^{(R)}$) has been reported with regard to neurobiological properties, no attention has been paid to the impact of EGb $761^{(R)}$ on the neuronal regulation of energy homeostasis. To evaluate the hypothesis that EGb $761^{(R)}$ affect the secretion of peptide tyrosine tyrosine (PYY) and the activation of free fatty acid receptor 4 (FFA4), which are involved in the neuronal circuitries that control energy homeostasis by inducing the transfer of information about the influx of energy to the brain, we examined whether EGb $761^{(R)}$ can stimulate PYY secretion in the enteroendocrine NCI-H716 cells and if EGb $761^{(R)}$ can activate FFA4 in FFA4-expressing cells. In NCI-H716 cells, EGb $761^{(R)}$ stimulated PYY secretion and the EGb $761^{(R)}$-induced PYY secretion was involved in the increase in intracellular $Ca^{2+}$ concentration and the activation of FFA4. Furthermore, in FFA4-expressing cells, EGb $761^{(R)}$ activated FFA4. These results suggest that EGb $761^{(R)}$ may affect the control of energy homeostasis via the regulation of PYY secretion and FFA4 activation.

• BMB Reports
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• v.39 no.2
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• pp.113-131
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• 2006

Sphingolipids have emerged as molecules whose metabolism is regulated leading to generation of bioactive products including ceramide, sphingosine, and sphingosine-1-phosphate. The balance between cellular levels of these bioactive products is increasingly recognized to be critical to cell regulation; whereby, ceramide and sphingosine cause apoptosis and growth arrest phenotypes, and sphingosine-1-phosphate mediates proliferative and angiogenic responses. Sphingosine kinase is a key enzyme in modulating the levels of these lipids and is emerging as an important and regulated enzyme. This review is geared at mechanisms of regulation of sphingosine kinase and the coming to light of its role in disease.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.566-574
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• 2023

The aim of this study was to investigate the regulation of lantipeptide production in Streptomyces globisporus SP6C4, which produces the novel antifungal lantipeptides conprimycin and grisin, and to identify the role of cytochrome P450 (P450) in tis regulation. To investigate the regulation of lantipeptide production, we created gene deletion mutants, including ΔP450, ΔtsrD, ΔlanM, ΔP450ΔtsrD, and ΔP450ΔlanM. These mutants were characterized in terms of their morphology, sporulation, attachment, and antifungal activity against Fusarium oxysporum. The gene deletion mutants showed distinct characteristics compared to the wild-type strain. Among them, the ΔP450ΔlanM double mutant exhibited a recovery of antifungal activity against F. oxysporum, indicating that P450 plays a significant role in regulating lantipeptide production in S. globisporus SP6C4. Our findings highlight the significant role of P450 in the regulation of lantipeptide production and morphological processes in S. globisporus. The results suggest a potential link between P450-mediated metabolic pathways and the regulation of growth and secondary metabolism in SP6C4, thereby highlighting P450 as a putative target for the development of new antifungal agents.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.359-366
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• 2001

Studies were carried out to explore the influence of dietary protein level on bone metabolism in uninephrectomized rat (experimental renal failure model) when dietary Ca and P contents were equal. Male rats were uninephrectomized or sham operated and fed 8%, 15% and 40% casein diets for 24 weeks. Ca and P contents of the all diet were 0.4% and 0.6% respectively. The results are summarized as follows. We did not found any significant difference in PTH and Ca level of the serum, Ca intake and Ca excretion among the experimental groups. There was significant positive correlation between the PTH and phosphate level. There was significant inverse correlation between serum Ca and creatinine level. The effect of the dietary protein level and renal mass loss on density and Ca contents of the bone were small and different according to the kinds of the bone. Low protein diet was associated with a significant enhancement of scapular density. Femur and vertebra density, however, were not influenced by dietary protein level and uninephrectomy. Light microscopic examination showed several calcified foci in the kidney in all experimental groups. Low protein diets have been used for a long time in the conservative management of chronic renal failure as they have a beneficial effect in preventing the appearance of symptoms. This study elucidated that part of beneficial effects of the low protein diet related to the suppression of the hyperphosphatemia. And these results, even though uninephrectomized rats fed high protein diet, the secondary hyperparathyroidism is supressed by the regulation of the P level. Therefore this study emphasized the need to pay more attention to the regulation of dietary P level as well as dietary protein content in chronic renal failure. (Korean J Nutrition 34(4): 359∼366, 2001)

• Molecules and Cells
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• v.42 no.4
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• pp.363-375
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• 2019

Fungal sectorization is a complex trait that is still not fully understood. The unique phenotypic changes in sporadic sectorization in mutants of CpBck1, a mitogen-activated protein kinase kinase kinase (MAPKKK) gene, and CpSlt2, a mitogen-activated protein kinase (MAPK) gene, in the cell wall integrity pathway of the chestnut blight fungus Cryphonectria parasitica have been previously studied. Although several environmental and physiological factors cause this sectoring phenotype, genetic variants can also impact this complex morphogenesis. Therefore, RNA sequencing analysis was employed to identify candidate genes associated with sectorization traits and understand the genetic mechanism of this phenotype. Transcriptomic analysis of CpBck1 and CpSlt2 mutants and their sectored progeny strains revealed a number of differentially expressed genes (DEGs) related to various cellular processes. Approximately 70% of DEGs were common between the wild-type and each of CpBck1 and CpSlt2 mutants, indicating that CpBck1 and CpSlt2 are components of the same MAPK pathway, but each component governs specific sets of genes. Functional description of the DEGs between the parental mutants and their sectored progenies revealed several key pathways, including the biosynthesis of secondary metabolites, translation, amino acid metabolism, and carbohydrate metabolism; among these, pathways for secondary metabolism and translation appeared to be the most common pathway. The results of this comparative study provide a better understanding of the genetic regulation of sector formation and suggest that complex several regulatory pathways result in interplays between secondary metabolites and morphogenesis.

• The Korea Journal of Herbology
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• v.31 no.2
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• pp.39-45
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• 2016

Objectives : Abnormal regulation of glucose and impaired lipid metabolism that result from a defective or deficient insulin are the key etiological factor in type 2 diabetes mellitus. The our study investigated the effects of Gamioknyeo-jeon (GO) on blood glucose and lipid metabolism improved by it in db/db mice (a murine model of type 2 diabetes mellitus).Methods : The animals were divided into 3 groups: Normal groups were not-treated C57BL/6 mice; Control groups were treated orally with DW in db/db mice; GO groups were treated orally with GO (200 ㎎/㎏/day) in db/db mice. After mice were treated with GO for 5 weeks, we measured AST, ALT, creatinine, BUN, body weight, food intake, blood glucose, insulin and lipid levels (total cholesterol, HDL cholesterol, and LDL cholesterol and atherogenic index(AI) and cardiac risk factor(CRF).Results : Serum AST, ALT, creatinine, BUN levels were not changed by GO do not show any toxic effects. GO groups were decreased in body weight, food intake and blood glucose level among compared to Control groups. Also, GO groups were found to have atherogenic Index and cardiac risk factor as well as lipid metabolism improvement (total cholesterol and LDL cholesterol decrease). Finally, GO groups were increased the insulin compared to Normal and control groups.Conclusions : We suggest that GO may have the control effects of diabetes mellitus by improving blood glucose control and lipid metabolism.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.196-201
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• 2013

Abnormal regulation of glucose and impaired lipid metabolism that result from a defective or deficient insulin are the key etiological factor in type 2 diabetes mellitus (T2DM). The our study evaluated the beneficial effect of diet supplementation with Lentinus edodes on hyperglycemia and lipid metabolism in normal and type 2 diabetic rats. The animals were divided into 4 groups: group I(control) rats were fed standard diet (12% of calories as fat); group II (T2DM) rats were fed HFD (40% of calories as fat) for 2 weeks and then injected with STZ (50 mg/kg); group III and group IV rats were continually fed a diet containing 1% and 10% Lentinus edodes for 4 weeks after T2DM induction, respectively. After 4 weeks we determined biochemical parameters such as glucose, insulin concentration, serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), and glycosylated hemoglobin (HbA1c) concentration were also measured. There was a significant reduction in serum TC and TG in the Lentinus edodes supplement groups. The Lentinus edodes diet supplementation were found to have a potent lipid metabolism improvement as well as LDL concentration decreased and HDL concentration was increased. Concentrations of blood glucose and HbA1c in the experimental groups II were significantly decreased after 4 weeks compared with the control group. The Lentinus edodes diet supplementation is useful in regulating the glucose level, improves the insulin, HbA1c, serum lipid metabolism in experimental diabetic rats. We suggest that Lentinus edodes supplementation may have the control effects of diabetes mellitus by improving blood glucose control and lipid metabolism.

• Archives of Pharmacal Research
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• v.28 no.1
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• pp.55-60
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• 2005

Leukocyte adhesion to the vascular endothelium is a critical initiating step in inflammation and atherosclerosis. We have herein studied the effect of manassantin A (1) and S (2), dineolignans, on interaction of THP-1 monocytic cells and human umbilical vein endothelial cells (HUVEC) and expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in HUVEC. When HUVEC were pretreated with 1 and 2 followed by stimulation with $TNF-{\alpha}$, adhesion of THP-1 cells to HUVEC decreased in dose-dependent manner with $IC_{50}$ values of 5 ng/mL and 7 ng/mL, respectively, without cytotoxicity. Also, 1 and 2 inhibited $TNF-{\alpha}-induceda$ up-regulation of ICAM-1, VCAM-1 and E-selectin. The present findings suggest that 1 and 2 prevent monocyte adhesion to HUVEC through the inhibition of ICAM-1, VCAM-1 and E-selectin expression stimulated by $TNF-\alpha$, and may imply their usefulness for the prevention of atherosclerosis relevant to endothelial activation.