• The Korean Journal of Physiology
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• 제30권2호
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• pp.231-236
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• 1996

In our previous study (Kim et al, 1991), GLUT 4 protein content correlated negatively with plasma glucose levels in skeletal muscles of STZ-induced diabetic rats. Thus, in this study, to confirm whether expression of GLUT 4 correlate negatively with degree of hyperglycemia, we measured levels of GLUT 4 mRNA in red and white gastrocnemius muscles in STZ-induced mild and severe diabetic rats. Rats were randomly assigned to control, mild, and severe diabetic groups, and the diabetes was induced by intraperitoneal administration of STZ. The experiment was carried out 10 days after STZ administration. Gastrocnemius red and white muscles were used fur the measurement of GLUT 4 expression. Plasma glucose levels of mild and severe diabetic rats were increased compared to control rats (control, mild, and severe diabetes; $6.4{\pm}0.32,\;9.4{\pm}0.68,\;and\;22.0{\pm}0.58$ mmol/L, respectively). Plasma insulin levels of mild and severe diabetic rats were decreased compared to control rats (control, mild, and severe diabetes; $198{\pm}37,\;l14{\pm}14,\;and\;90{\pm}15$ pmol/L, respectively). GLUT 4 mRNA levels of gastrocnemius red muscles in mild and severe diabetic rats were decreased compared to control rats ($64{\pm}1.2%\;and\;71{\pm}2.0%$ of control, respectively), but GLUT 4 mRNA levels in gastrocnemius white muscles were unaltered in diabetic rats. In summary, GLUT 4 mRNA levels were decreased in STZ-induced diabetic rats but did not correlated negatively with degree of hyperglycemia, and this result suggest that the regulatory mechanisms of decreased GLUT 4 mRNA levels are hypoinsulinemia and/or other metabolic factor but not hyperglycemia. And regulation of GLUT 4 expression in STZ-induced diabetes between red and white enriched skeletal muscles may be related to a fiber specific gene regulatory mechanism.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.844-855
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• 2017

Phosphate-solubilizing bacteria (PSB) have the ability to dissolve insoluble phosphate and enhance soil fertility. However, the growth and mineral phosphate solubilization of PSB could be affected by exogenous soluble phosphate and the mechanism has not been fully understood. In the present study, the growth and mineral phosphate-solubilizing characteristics of PSB strain Burkholderia multivorans WS-FJ9 were investigated at six levels of exogenous soluble phosphate (0, 0.5, 1, 5, 10, and 20 mM). The WS-FJ9 strain showed better growth at high levels of soluble phosphate. The phosphate-solubilizing activity of WS-FJ9 was reduced as the soluble phosphate concentration increased, as well as the production of pyruvic acid. Transcriptome profiling of WS-FJ9 at three levels of exogenous soluble phosphate (0, 5, and 20 mM) identified 446 differentially expressed genes, among which 44 genes were continuously up-regulated when soluble phosphate concentration was increased and 81 genes were continuously down-regulated. Some genes related to cell growth were continuously up-regulated, which would account for the better growth of WS-FJ9 at high levels of soluble phosphate. Genes involved in glucose metabolism, including glycerate kinase, 2-oxoglutarate dehydrogenase, and sugar ABC-type transporter, were continuously down-regulated, which indicates that metabolic channeling of glucose towards the phosphorylative pathway was negatively regulated by soluble phosphate. These findings represent an important first step in understanding the molecular mechanisms of soluble phosphate effects on the growth and mineral phosphate solubilization of PSB.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.100.1-100
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• 2003

A dctA gene encoding a protein with identity to a C4-dicarboxylate/H+ was cloned from a beneficial biocontrol bacterium, P. chororaphis O6. Expression of the dctA was induced in minimal medium by several organic acids and was repressed by glucose. Highest expression was observed in early-log cells grown on fumarate and succinate with decline as cells approached late-log phase. The dctA transcript accumulated weakly when cells were grown on malate but strong expression was observed with benzoate. Expression of the dctA transcript was repressed in early-log cells upon addition of glucose to fumarate, but was detected as the cell culture aged. A dctA-deficient mutant of O6, constructed by marker exchange mutagenesis, did not grow on minimal medium containing succinate, benzoate, or fumarate, and growth on malate was delayed. The dctA mutant and wild type grew equally on glucose. The dctA mutant on cucumber roots in sterilized potting soil was colonized at levels comparable to those of the wild type, but induction level of disease resistance by the mutant against target leaf spot disease was decreased. These results may indicate that the dctA is essential for utilization of certain organic acids and its expression is controlled by the availability of sugars. In addition, the dctA is not essenitial for cucumber root colonization, but important for induction of disease resistance.

• BMB Reports
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• 제57권2호
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• pp.92-97
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• 2024

Elevated blood glucose is associated with an increased risk of atherosclerosis. Data from the current study showed that glucosamine (GlcN), a normal glucose metabolite of the hexosamine biosynthetic pathway (HBP), promoted lipid accumulation in RAW264.7 macrophage cells. Oleic acid- and lipopolysaccharide (LPS)-induced lipid accumulation was further enhanced by GlcN in RAW264.7 cells, although there was no a significant change in the rate of fatty acid uptake. GlcN increased acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), scavenger receptor class A, liver X receptor, and sterol regulatory element-binding protein-1c (SREBP-1c) mRNA expression, and; conversely, suppressed ATP-binding cassette transporter A1 (ABCA-1) and ABCG-1 expression. Additionally, GlcN promoted O-GlcNAcylation of nuclear SREBP-1 but did not affect its DNA binding activity. GlcN stimulated phosphorylation of mammalian target of rapamycin (mTOR) and S6 kinase. Rapamycin, a mTOR-specific inhibitor, suppressed GlcN-induced lipid accumulation in RAW264.7 cells. The GlcN-mediated increase in ACC and FAS mRNA was suppressed, while the decrease in ABCA-1 and ABCG-1 by GlcN was not significantly altered by rapamycin. Together, our results highlight the importance of the mTOR signaling pathway in GlcN-induced macrophage lipid accumulation and further support a potential link between mTOR and HBP signaling in lipogenesis.

• 한국응용곤충학회지
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• 제55권1호
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• pp.53-62
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• 2016

본 연구의 목적은 벼메뚜기(Oxya chinensis sinuosa) 분말 섭취가 유산소성 운동훈련(트레드밀 달리기)의 병행 유무에 의해 ICR 생쥐의 에너지 대사를 증가시키는지를 알아보고자 하는 것이다. 이 목적을 달성하기 위하여, 28 마리의 ICR 생쥐를 보통식 대조군(CON), 보통식 대조군으로서 운동훈련 병행군(COEX), 벼메뚜기 분말이 혼합된 사료 섭취군(GH), 그리고 벼메뚜기 분말이 혼합된 사료를 섭취함과 동시에 운동훈련을 병행군(GHEX)으로 구분하였다. 벼메뚜기 분말 사료섭취 및 운동은 6주간 진행하였다. 체중증가율은 유의하지 않았다. 지방량은 GH와 GHEX에서 유의하게 감소하였다. 혈중 glutamic oxaloacetic transaminase와 glutamic pyruvic transaminase 수준은 처치 집단간 변화가 없었다. 제2형 당수송체 및 제4형 당수송체는 처치 집단간 유의한 차이가 없었다. GHEX의 fibronectin type III domain-containing protein 5 단백질 발현량이 가장 높았다. AMP-activated protein kinase 단백질 수준은 GHEX에서 유의하게 증가하였다. Glycogen synthase kinase 3 beta 단백질 발현량은 GHEX가 CON과 비교할 때 감소하였다. 이러한 결과들은 벼메뚜기 분말을 섭취하면서 지구성 운동훈련을 하는 경우에 에너지 대사에 영향을 준다는 것을 제시하고 있다.

• Journal of Ginseng Research
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• 제48권1호
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• pp.12-19
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• 2024

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

• The Korean Journal of Physiology and Pharmacology
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• 제17권3호
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• pp.245-251
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• 2013

The purpose of this study was to investigate the effects of fluvastatin on the pharmacokinetics of repaglinide in rats. The effect of fluvastatin on P-glycoprotein and CYP3A4 activity was evaluated. The pharmacokinetic parameters and blood glucose concentrations were also determined after oral and intravenous administration of repaglinide to rats in the presence and absence of fluvastatin. Fluvastatin inhibited CYP3A4 activity in a concentration-dependent manner with a 50% inhibition concentration($IC_{50}$) of 4.1 ${\mu}M$ and P-gp activity. Compared to the oral control group, fluvastatin significantly increased the AUC and the peak plasma level of repaglinide by 45.9% and 22.7%, respectively. Fluvastatin significantly decreased the total body clearance (TBC) of repaglinide compared to the control. Fluvastatin also significantly increased the absolute bioavailability (BA) of repaglinide by 46.1% compared to the control group. Moreover, the relative BA of repaglinide was 1.14- to 1.46-fold greater than that of the control. Compared to the i.v. control, fluvastatin significantly increased the $AUC_{0-{\infty}}$ of i.v. administered repaglinide. The blood glucose concentrations showed significant differences compared to the oral controls. Fluvastatin enhanced the oral BA of repaglinide, which may be mainly attributable to the inhibition of the CYP3A4-mediated metabolism of repaglinide in the small intestine and/or liver, to the inhibition of the P-gp efflux transporter in the small intestine and/or to the reduction of TBC of repaglinide by fluvastatin. The study has raised the awareness of potential interactions during concomitant use of repaglinide with fluvastatin. Therefore, the concurrent use of repaglinide and fluvastatin may require close monitoring for potential drug interactions.

• Journal of Yeungnam Medical Science
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• 제14권1호
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• pp.53-66
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• 1997

인슐린 저항성이란 인슐린의 생물학적 효과가 감소하는 상태를 말하며 당뇨병의 중요한 병리기전이다. 인슐린 저항성은 매우 다양한 특성을 가지고 있으며 유전적인 요인이나 후천적인 요인에 의하여 발생한다. 이제까지 가장 잘 알려진 인슐린 저항성의 유발인자로는 고혈당과 고인슐린증이 있다. 장기간의 고혈당이나 고인슐린증은 가장 중요한 인슐린의 작용조직인 골격근에서 인슐린 수용체의 결합능을 감소시키고 당섭취에 필요한 제 4형 당수송체의 발현을 억제하는 것으로 알려져 있다. 그러나 이들 인자는 모두 골격근에서 당섭취를 증가시키는 것으로서 인슐린 저항성은 말초조직이 세포내로의 과도한 영양소 섭취를 방지하기 위하여 작동시키는 조절기전일 가능성을 생각할 수 있다. 본 연구에서는 단기간의 당섭취 증가가 더 이상의 당섭취를 억제할 수 있는지를 평가하고 그 기전을 규명하고자 흰쥐에서 2시간 동안 다양한 조건으로 당섭취를 유도하고 1 시간의 휴식기간을 가진 후 인슐린 예민도를 측정하고 골격근을 분리하여 인슐린 수용체와 제 4 형 당수송체를 분석하여 당섭취량과 인슐린 감수성과의 상관관계를 규명하고 인슐린 수용체 결합능과 제 4형 당수송체량을 비교하였다. 실험군은 hyperinsulinemic glucose clamp 전에 시행한 당섭취의 조건으로써 5개 군으로 구분하였다. 제 I 군은 대조군으로 생리식염수만 주입하여 기초상태의 인슐린 농도와 혈당을 유지하였으며, 제 II 군은 somatostatin과 포도당을 주입하여 정상 인슐린농도와 고혈당을 유지하였으며, 제 III 군은 포도당을 주입하여 고인슐린증과 고혈당을 유지하였고, 제 IV 군은 인슐린(100 mU/kg/min)과 포도당을 주입하여 초고인슐린증(${\sim}4000{\mu}U/ml$)과 정상혈당(~100 mg/dl)으로 유지하였으며, 그리고 제 V 군은 인슐린과 포도당을 주입하여 초고인슐린증과 고혈당(~200 mg/dl)을 유지하였다. 체중, 공복시 혈당 및 인슐린 농도는 각 군 간에 유의한 차이가 없었다. Hyperinsulinemic euglycemic clamp 전에 주입한 포도당의 총량(gm/kg)은 제 II 군이 $1.88{\pm}0.151$, 제 III 군이 $2.69{\pm}0.239$, 제 IV 군이 $3.54{\pm}0.198$, 그리고 제 V 군이 $4.32{\pm}0.621$이었다. Hyperinsulinemic euglycemic clamp의 평형상태 당제거율(mg/kg min)은 제 I 군이 $16.9{\pm}1.74$, 제 II 군이 $13.5{\pm}0.53$, 제 III 군이 $11.2{\pm}0.52$, 제 IV 군이 $13.2{\pm}0.92$, 그리고 제 V 군이 $10.4{\pm}0.41$로 전체 군 간에 유의한 차이가 있었으며(p<0.001) 각 군간의 비교에서 제 II, III, IV, V 군의 값이 제 I 군에 비하여 유의하게 낮았다 (p<0.05). 전체 실험동물에서 포도당 주입량과 당제거율 사이에 역상관관계 (r=-0.701, p<0.001)를 보였다. 인슐린 수용체 결합과 Western blot으로 분석한 제 4형 당수송체량은 각 군 간에 유의한 차이가 없었다. 이상의 결과로 미루어 단기간의 당섭취 증가가 더이상의 당섭취를 억제할 수 있으나 인슐린 수용체 결합과 제 4형 당수송체의 숫적 감소없이 발생하였다.

• 한방비만학회지
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• 제22권2호
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• pp.102-114
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• 2022

Objectives: We investigated the effects of Allii Fistulosi Bulbus (AFB) on high fat diet (HFD)-induced obesity in mice and the regulation of energy metabolism in muscle tissues of mice. Methods: The C57BL/6 mice (6 weeks, male) were fed a HFD for 8 weeks and then administrated with AFB extract at 500 mg/kg (p.o.) once daily for 4 weeks. The body weight (BW), muscle weight, calorie intake, fasting blood glucose (FBG) and serum glucose, insulin, and low-density lipoprotein-cholesterol (LDL-C) levels were measured in mice. It was also observed the histological changes of pancreas, liver, and fat tissues with hematoxylin and eosin staining. It was investigated the phosphorylation of insulin receptor substrate 1 (IRS-1), Ser/Thr kinase (AKT), and adenosine monophosphate-activated protein kinase (AMPK), and the expression of phosphoinositide 3-kinase, glucose transporter type 4 (GLUT4), and sirtuin1 (Sirt1) in gastrocnemius tissues by western blot, respectively. Results: The increases of BWs, calorie intakes and FBG levels in obesity mice were decreased significantly by the administration of AFB extract. The AFB extract administration was reduced significantly serum levels of glucose, insulin, and LDL-C in obesity mice. The AFB extract inhibited lipid accumulation in liver tissues, hyperplasia of pancreatic islets, and enlargement of fat tissues in obesity mice. The phosphorylation of IRS-1 and AKT was increased significantly in muscle tissues and AMPK phosphorylation and the GLUT4 and Sirt1 expression were decreased significantly in muscle tissues after the AFB administration. Conclusions: Our study indicates that AFB extract improves symptoms of obesity through regulation of energy regulating proteins in muscle tissues.

• Food Science and Biotechnology
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• 제16권2호
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• pp.212-217
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• 2007

Fucoidan (fucan sulfate) is a fucose-containing sulfated polysaccharide from brown algae such as Fucus vesiculosus, Ecklonia kurome, and Cladosiphon okamuranus. The aim of this study was to investigate the effect of fucoidan on the expression of diabetes-related genes in mouse cell line 3T3-L1. 3T3-L1 adipocytes were cultured for 48 hr with or without fucoidan (10, 100, and 500 ppm) on a 60 mm dish. Reverse transcription polymerase chain reaction (RT-PCR) was used for measurement of peroxisome proliferators activated receptor ${\gamma}\;(PPAR{\gamma})$, CCAAT/enhancer binding protein ${\alpha}\;(C/EBP{\gamma})$, and glucose transporter 4 (GLUT4) RT-PCR analysis revealed that expression level of GLUT4, $PPAR{\gamma}$, and $C/EBP{\alpha}$ mRNAs increased with fucoidan treatment from 10 to 500 ppm in a dose-dependent manner. Fucoidan appears to enhance insulin sensitivity by increasing the expression level of diabetes-related genes in 3T3-L1 adipocytes. Therefore, fucoidan is potentially useful as a natural therapeutic material for hyperglycemia in type II diabetes patients.