• Reproductive and Developmental Biology
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• 제33권4호
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• pp.211-216
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• 2009

A cell frequently utilizes glucose as a fuel of energy and a major substrate of lipid and protein syntheses. A regulation of glucose movement into and out of the cells is precisely controlled by cooperative works of passive and sodium-dependent active processes. At least 13 glucose cotransporter (Slc2a, GLUT) isoforms involve in passive movement of glucose in cells. The efferent ductules (EDs) play in a number of important functions for maintenance of male fertility. In the present study, using real-time PCR analysis, we determined gene expression of five Slc2a isoforms in the EDs. In addition, we compared expression levels of these Slc2a isoforms according to postnatal development ages, 1 week, 2 weeks, 1 month, and 3 months. Results from the current study showed that expression of Slc2a1, Slc2a3, and Slc2a5 mRNAs reached the highest levels at 1 month of age, followed by a transient decrease at 3 months of age. In addition, the level of Slc2a4 mRNA reminded at steady until 1 month of age and was significantly reduced at 3 months of age, whereas the highest level of Slc2a 8 mRNA was detected at 2 weeks of age. Data from the present study indicate a differential expression of various Slc2a isoforms in the ED according to postnatal ages. Thus, it is believed that glucose movement through the epithelial cells in the ED would be regulated by the coordinated manner among Slc2a isoforms expressed at a given age.

• 한국식품영양과학회지
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• 제44권3호
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• pp.324-330
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• 2015

본 연구에서는 C57BL/6J ob/ob 마우스를 이용하여 한국산 겨우살이 냉수 추출물(KME)의 항당뇨 활성을 조사하였다. 50 혹은 100 mg/kg의 KME를 1일 1회씩 경구투여 한 결과 KME 투여 개시 5일 후부터 ob/ob 마우스의 혈당이 유의하게 억제되었으며, 10일 후부터 안정된 억제 효과를 나타내고 대조군에 비해 20% 이상의 혈당강하 효과를 나타내었다. 경구 당부하 실험(OGTT)에서는 KME 경구투여 마우스에서 유효한 당부하 억제 활성이 관찰되었다. 또한 KME 경구 투여는 ob/ob 당뇨 마우스의 혈액 내 총 콜레스테롤과 중성 지질의 농도를 억제하는 것으로 나타났다. 한편 C2C12 근육세포를 이용한 in vitro 실험에서 KME를 처리함으로써 glucose uptake가 현저히 증가하였다. 한편 매우 흥미롭게도 KME를 처리한 C2C12 근육세포에 있어서 미토콘드리아 생성과 산화대사 조절물질인 peroxisome proliferator-activated receptor gamma coactivator 1-${\alpha}(PGC-1{\alpha})$를 비롯하여 glucose transporter type 4(GLUT4), estrogen-related receptor-${\alpha}(ERR-{\alpha})$, nuclear respiratory factor-1(NRF-1) 그리고 mitochondrial transcription factor A(TmfA)와 같은 $PGC-1{\alpha}$ 관련 유전자들의 발현이 증가하는 것으로 확인되었다. 이 결과는 KME가 2형 당뇨에 대한 치료물질로서의 작용을 지니며 이러한 KME의 항당뇨 활성은 미토콘드리아 생성의 조절과 관련 있는 것으로 추정된다.

• 한국가금학회지
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• 제43권1호
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• pp.47-54
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• 2016

Coenzyme Q10(CoQ10)은 자연계에 널리 분포하는 화합물로 세포호흡과 항산화제로서 그 기능이 잘 알려졌지만, 최근 유전자들의 발현 조절자로서의 가능성도 제시되었다. 따라서 본 연구는 산란계에서 CoQ10의 첨가 급이가 콜레스테롤과 지방산 대사관련 유전자들의 발현에 미치는 영향을 관찰하고자 실시하였다. Lohmann Brown(40주령) 36수를 CoQ10의 첨가원에 따라 대조군(CON, basal diet(BD)), CoQ10 건조분말 급여군(T1, BD+CoQ10 100 mg/kg 사료) 및 CoQ10 건조분말 유화처리군(T2, BD+micellar of CoQ10 100 mg/kg 사료) 등 모두 3처리구로 설정하여 5주간 사양시험을 실시하였다. 시험 종료 후 각 개체의 간으로부터 total RNA를 추출하고, real-time PCR을 이용하여 유전자들의 발현을 분석하였다. 콜레스테롤 합성 과정에서 주요 조절 효소인 HMGCoA reductase(HMGCR)의 유전자 발현은 대조구에 비하여 CoQ10 분말첨가인 T1과 유화처리된 T2 처리구에서 모두 약 50%씩 억제되었다(p<0.05). 내생 콜레스테롤의 합성을 촉진시키는 전사인자인 SREBP2 mRNA 발현 또한 대조구와 비교해서 T1과 T2에서 각각 30%와 40% 감소하였다(p<0.05). CoQ10의 첨가 급이는 대조구에 비하여 liver X receptor(LXR) 유전자가 약 30~35% 그 발현이 억제되었으며, sterol regulatory element-binding proteins(SREBPs)1 또한 T2에서 약 40% 유전자 발현이 감소하였다(P<0.05). 전사인자인 $PPAR{\gamma}$와 XBP1은 CoQ10에 의하여 약 15~40% 수준으로 효과적으로 억제됨을 확인하였다(p<0.05). 세포 내부로의 에너지 공급원인 포도당의 흡수를 담당하는 GLUT2는 약 35~60% 그리고 GLUT8은 약 25~30%의 유전자발현 각각 감소함을 보였다(p<0.05). CoQ10의 섭취는 중성지방 합성을 위한 지방합성효소(FASN)의 유전자 발현을 분말처리군에서 약 30%, 유화처리군에서 약 65% 억제됨을 확인하였다(P<0.05). 본 연구결과는 CoQ10 첨가급여가 콜레스테롤 및 지방대사 관련 유전자 발현에 영향을 미치며, 세포내 콜레스테롤과 지방의 생성도 억제할 수 있음을 보여주었다.

• Journal of Ginseng Research
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• 제41권3호
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• pp.257-267
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• 2017

Background: Heat-processed ginseng, sun ginseng (SG), has been reported to have improved therapeutic properties compared with raw forms, such as increased antidiabetic, anti-inflammatory, and antihyperglycemic effects. The aim of this study was to investigate the antiobesity effects of SG through the suppression of cell differentiation and proliferation of mouse 3T3-L1 preadipocyte cells and the lipid accumulation in Caenorhabditis elegans. Methods: To investigate the effect of SG on adipocyte differentiation, levels of stained intracellular lipid droplets were quantified by measuring the oil red O signal in the lipid extracts of cells on differentiation Day 7. To study the effect of SG on fat accumulation in C. elegans, L4 stage worms were cultured on an Escherichia coli OP50 diet supplemented with $10{\mu}g/mL$ of SG, followed by Nile red staining. To determine the effect of SG on gene expression of lipid and glucose metabolism-regulation molecules, messenger RNA (mRNA) levels of genes were analyzed by real-time reverse transcription-polymerase chain reaction analysis. In addition, the phosphorylation of Akt was examined by Western blotting. Results: SG suppressed the differentiation of 3T3-L1 cells stimulated by a mixture of 3-isobutyl-1-methylxanthine, dexamethasone, and insulin (MDI), and inhibited the proliferation of adipocytes during differentiation. Treatment of C. elegans with SG showed reductions in lipid accumulation by Nile red staining, thus directly demonstrating an antiobesity effect for SG. Furthermore, SG treatment down-regulated mRNA and protein expression levels of peroxisome proliferator-activated receptor subtype ${\gamma}$ ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein-alpha ($C/EBP{\alpha}$) and decreased the mRNA level of sterol regulatory element-binding protein 1c in MDI-treated adipocytes in a dose-dependent manner. In differentiated 3T3-L1 cells, mRNA expression levels of lipid metabolism-regulating factors, such as amplifying mouse fatty acid-binding protein 2, leptin, lipoprotein lipase, fatty acid transporter protein 1, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase, were increased, whereas that of the lipolytic enzyme carnitine palmitoyltransferase-1 was decreased. Our data demonstrate that SG inversely regulated the expression of these genes in differentiated adipocytes. SG induced increases in the mRNA expression of glycolytic enzymes such as glucokinase and pyruvate kinase, and a decrease in the mRNA level of the glycogenic enzyme phosphoenol pyruvate carboxylase. In addition, mRNA levels of the glucose transporters GLUT1, GLUT4, and insulin receptor substrate-1 were elevated by MDI stimulation, whereas SG dose-dependently inhibited the expression of these genes in differentiated adipocytes. SG also inhibited the phosphorylation of Akt (Ser473) at an early phase of MDI stimulation. Intracellular nitric oxide (NO) production and endothelial nitric oxide synthase mRNA levels were markedly decreased by MDI stimulation and recovered by SG treatment of adipocytes. Conclusion: Our results suggest that SG effectively inhibits adipocyte proliferation and differentiation through the downregulation of $PPAR{\gamma}$ and $C/EBP{\alpha}$, by suppressing Akt (Ser473) phosphorylation and enhancing NO production. These results provide strong evidence to support the development of SG for antiobesity treatment.

• 생명과학회지
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• 제31권2호
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• pp.209-218
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• 2021

본 연구는 꾸지뽕 신초에 부착된 잎을 6단계 즉 정아의 잎(L0), 정아부에서 하부의 순서대로 L1, L2, L3, L4 및 기부의 잎을 L5로 분류하여 채취하였다. 신초의 위치에 따라서 분류한 잎을 70% 에틸알콜로 추출한 다음 3T3-L1 cell line을 이용하여 지방분화 억제 효과를 스크린하고, 가장 효과가 좋았던 꾸지뽕 신초 정단잎(CTL0) 추출물의 작용기작을 규명하였다. 꾸지뽕 신초 정단잎(CTL0) 추출물의 지방분화 억제효과가 가장 좋았으며, 신초의 중간 잎인 CTL2까지는 정단 잎에서부터 중간 잎 추출물일수록 효과가 감소하였으며, 신초의 중간 하부 잎인 CTL3부터 기부 잎인 CTL5 추출물은 100 ㎍/ml의 고농도에서 효과가 없었다. 꾸지뽕 신초 정단잎(CTL0) 추출물을 12.5, 25 및 50 ㎍/ml의 농도로 처리하여 Oil Red O를 분석한 결과, 농도 의존적으로 3T3-L1세포의 지방분화를 억제시켰다. 3T3-L1 세포에 지방분화물질인 insulin, dexamethasone 및 rosiglitazone을 첨가한 분화배지(DM)에서는 배지내에 glucose의 함량이 낮았으나, CTL0 추출물의 처리는 배지에 glucose함량이 많이 남아있었기 때문에 세포내로 glucose의 흡수를 억제시켰으며, 세포내 중성지방의 함량도 감소하였다. CTL0처리는 전구지방세포에서 지방세포로 분화될 때에 주요 전사인자로 알려진 PPARγ와 PPARγ의 target 유전자인 LPL, A-FABP 및 Glut4 단백질의 발현을 농도 의존적으로 억제하였다. 따라서 꾸지뽕 신초 정단잎(CTL0) 추출물은 항비만 효과가 우수한 소재로서 활용가치가 높을 것으로 사료된다.

• 생약학회지
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• 제36권4호통권143호
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• pp.291-298
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• 2005

Anti-hyperglycemic effects of 17 medicinal plants that have been used for ameliorating diabetes in oriental medicine were evaluated using glucose transport assay in 3T3-L1 adipocytes. Higher activities were obtained by treating water or alcohol extract of Phellodendri Cortex (PC), which showed enhancing effects both on basal and insulin-stimulated glucose uptake. The latter effect of PC was completely inhibited by wortmannin, a specific inhibitor for phosphatidyl inositol 3-kinase (PI 3-kinase), but not affected by SB203580, A specific inhibitor for p38 mitogen-activatedprotein kinase(MAPK). Genistein, an inhibitor for tyrosine kinases, abolished the PC effects completely. Treatment of vanadate, an inhibitor for tyrosine phosphatases, together with PC showed no significant synergic enhancement in glucose uptake. The results of inhibitors associated with insulin signaling pathway indicated that extracts of PC enhance glucose uptake by PI-3 kinase activation which is an upstream event for GLUT4 translocation. Antidiabetic effects of PC extract might be also due to enhanced tyrosine phosphorylation and reduced tyrosine dephosphorylation. In addition, PC accelerated insulin-stimulated glucose uptake in insulin-resistant cells, recovering the uptake level close to that of normal cells. These findings may offer a new way to utilize extracts of PC as novel anti-hyperglycemic agents.

• Molecules and Cells
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• 제19권1호
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• pp.31-38
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• 2005

Human embryonic stem (hES) cells have unique features including unlimited growth capacity, expression of specific markers, normal karyotypes and an ability to differentiate. Many investigators have tried to use hES cells for cell-based therapy, but there is little information about the properties of available hES cell lines. We compared the characteristics of three hES cell lines. The expression of SSEA-1, -3, -4, and APase, was examined by immunocytochemistry, and Oct-4 expression was analyzed by RT-PCR. Differentiation of the hES cells in vitro and in vivo led to the formation of embryoid bodies (EBs) or teratomas. We examined the expression of tissue-specific markers in the differentiated cells by semiquantitative RT-PCR, and the ability of each hES cell line to proliferate was measured by flow cytometry of DNA content and ELISA. The three hES cell lines were similar in morphology, marker expression, and teratoma formation. However there were significant differences (P < 0.05) between the differentiated cells formed by the different cell lines in levels of expression of tissue-specific markers such as renin, kallikrein, Glut-2, ${\beta}-$ and ${\delta}-globin$, albumin, and ${\alpha}1-antitrypsin$ (${\alpha}1-AT$). The hES cell lines also differed in proliferative activity. Our observations should be useful in basic and clinical hES cell research.

• Journal of Nutrition and Health
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• 제55권1호
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• pp.70-84
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• 2022

Purpose: Skeletal muscles display significant heterogeneity in metabolic responses, owing to the composition of metabolically distinct fiber types. Recently, numerous studies have reported that in skeletal muscles, suppression of genes related to fatty acid channeling alters the triacylglycerol (TAG) synthesis and switches the energy substrates. However, such responses may differ, depending on the type of muscle fiber. Hence, we conducted in vitro and animal studies to compare the metabolic responses of different types of skeletal muscle fibers to the deficiency of fatty acyl-CoA synthetase (Acsl)6, one of the main fatty acid-activating enzymes. Methods: Differentiated skeletal myotubes were transfected with selected Acsl6 short interfering RNA (siRNA), and C57BL/6J mice were subjected to siRNA to induce Acsl6 deficiency. TAG accumulation and expression levels of insulin signaling proteins in response to acute glucose supplementation were measured in immortalized cell-based skeletal myotubes, oxidative muscles (OM), and glycolytic muscles (GM) derived from the animals. Results: Under conditions of high glucose supplementation, suppression of the Acsl6 gene resulted in decreased TAG and glycogen synthesis in the C2C12 skeletal myotubes. The expression of Glut4, a glucose transporter, was similarly downregulated. In the animal study, the level of TAG accumulation in OM was higher than levels determined in GM. However, a similar decrease in TAG accumulation was obtained in the two muscle types in response to Acsl6 suppression. Moreover, Acsl6 suppression enhanced the phosphorylation of insulin signaling proteins (Foxo-1, mTORc-1) only in GM, while no such changes were observed in OM. In addition, the induction ratio of phosphorylated proteins in response to glucose or Acsl6 suppression was significantly higher in GM than in OM. Conclusion: The results of this study demonstrate that Acsl6 differentially regulates the energy metabolism of skeletal muscles in response to glucose supplementation, thereby indicating that the fiber type or fiber composition of mixed muscles may skew the results of metabolic studies.

• 대한의생명과학회지
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• 제8권4호
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• pp.211-215
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• 2002

The baculovirus/Sf9 cell expression can be employed as a powerful system for producing large amounts of the human erythrocyte glucose transporter, GLUT1 heterologously In order to exploit the system further, it is necessary to develop a convenient method for demonstrating that the transporter expressed in insect cells is biologically active. To achieve this, we have expressed the human CLUT1 in insect cells and photolabelled the expressed protein with [$^3$H] cytochalasin B, a potent inhibitor of the human erythrocyte glucose transporter. Subsequently, the labelled proteins were analysed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Membranes labelled with [$^3$H] cytochalasln B in the presence of L-Glucose yielded a single sharp peak of labelling of apparent $M_r$ 45,000 on SDS/polyacrylamide gels. The mobility of this peak corresponded exactly to that of the band detected by anti-glucose transporter antibodies on Western blots of membranes prepared from insect cells infected with recombinant virus. In addition, the sharpness of the radioactive peak provides further evidence for the conclusion that the expressed protein is much less heavily and heterogeneously glycosylated than its erythrocyte counterpart. No peak of labelling was seen with the membranes prepared from non-infected Sf9 cells. Furthermore, the incorporation of label into this peak was completely inhibited by the presence of 500 mM-D-Glucose during tile photolabelling procedure, showing the stereoselectivity of the labelling. These evidences clearly show that human glucose transporter expressed in insect cells exhibits native-like biological activity, and that photolabelling with [$^3$H] cytochalasin B can be a convenient means for analysing the biological activity of the transport protein expressed in insect cells.

• The Korean Journal of Physiology and Pharmacology
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• 제25권4호
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• pp.341-354
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• 2021

Cardamonin (CARD) is a chalconoid with anti-inflammatory and antioxidant properties, and it is present in several plants. We sought to explore whether CARD exerts any positive effects against hyperglycemia-induced testicular dysfunction caused by type 2 diabetes and aimed to identify its possible intracellular pathways. Adult male rats were subdivided into six groups: control, CARD, diabetic (DM), DM + glibenclamide (GLIB), DM + CARD and DM + GLIB + CARD. Type 2 DM induced a significant increase in blood glucose and insulin resistance, along with diminished serum insulin, testosterone and gonadotropins levels, which were associated with the impairment of key testicular androgenic enzymes and cellular redox balance. Administration of CARD at a dose of 80 mg/kg for 4 weeks effectively normalized all of these alterations, and the improvement was confirmed by epididymal sperm analysis. After treatment with CARD, the pathological changes in spermatogenic tubules were markedly improved. Significantly, CARD upregulated testicular glucose transporter-8 (GLUT-8) expression and had inhibitory effects on elevated autophagy markers and caspase-3 immunoreactive cells. Furthermore, our results revealed that CARD was able to attenuate damage via activation of Nrf2 through the p62-dependent degradation of testicular anti-Kelch-like ECH-associated protein-1 (Keap-1). In conclusion, this study suggests that CARD provides protection against diabetic stress-mediated testicular damage. The use of CARD with conventional anti-diabetic therapy was associated with improved efficacy compared with conventional therapy alone.