• 대한의생명과학회지
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• 제11권4호
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• pp.487-492
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• 2005

The baculovirus/insect cell expression system is of great value in the study of structure-function relationships in mammalian glucose-transport proteins by site-directed mutagenesis and for the large-scale production of these proteins for mechanistic and biochemical studies. Spodoptera frugiperda Clone 21 (Sf2l) cells grow well on TC-100 medium that contains $0.1\%$ D-glucose as the major carbon source, strongly suggesting the presence of endogenous glucose transporters. However, very little is known about the properties of the endogenous sugar transporter(s) in Sf2l cells, although a saturable transport system for hexose uptake has been previously revealed in the Sf cells. In order to further examine the substrate and inhibitor recognition properties of the Sf2l cell transporter, the ability of hexoses to inhibit 2-deoxy-D-glucose (2dGlc) transport was investigated by measuring inhibition constants $(K_i)$. The $K_i's$ for reversible inhibitors were determined from plots of uptake versus inhibitor concentration. Transport was effectively inhibited by D-mannose and D-glucose. Of the hexoses tested, L-glucose had the least effect on 2dGlc transport in the Sf2l cells, indicating that the transport is stereoselective. Unlike the human HepG2 type glucose transport system, D-mannose had a somewhat greater affinity for the Sf2l cell transporter than D-glucose, implying that the hydroxyl group at the C-2 position is not necessary for strong binding. However, epimerization at the C-4 position of D-glucose (D-galactose) resulted in a dramatic decrease in affinity of the hexose for the Sf2l cell transporter. Such a lowering of affinity might be the result of the involvement of the C-4 hydroxyl in hydrogen bonding. It is therefore suggested that Sf2l cells were found to contain an endogenous sugar transport activity that in several aspects resembles the human HepG2 type glucose transporter, although the insect and human transporters do differ in their affinity for cytochalasin B.

• 한국식품저장유통학회지
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• 제24권7호
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• pp.1007-1016
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• 2017

다슬기는 예로부터 간염, 간경화, 지방간 등의 치료 및 개선에 이용되어 왔으며, 특히 소변불통, 소갈증(당뇨) 등의 약용으로 이용되어 왔다. 본 연구에서는 이러한 다슬기를 대상으로 항당뇨에 대한 효능을 과학적으로 검증하고 그 기작을 규명하고자 하였다. 먼저 다슬기의 생물학적 기능성을 높이기 위해 효소 가수분해를 실시하였으며, protamex에 의한 가수분해도는 10시간 후 약 43% 수준을 나타내었다. PTP1B는 인슐린 신호전달기전에서 IRS-1의 인산화를 방해하여 인슐린 민감성을 저해시키는 효소이다. protamex를 이용한 다슬기 가수분해물(MPH)의 PTP1B에 대한 저해활성은 $15.42{\pm}1.1{\mu}g/mL$의 $IC_{50}$ 값을 나타내어 양성대조군 ursolic acid의 $16.7{\mu}g/mL$ 보다 높은 저해활성을 보이면서 강한 항당뇨 활성 소재로서의 가능성을 보였다. 이에 따라 유리지방산을 이용하여 C2C12 myoblast에서 인슐린 저항성을 유도하고, MPH에 의한 포도당 흡수 정도를 확인하였다. 그 결과, 1 mM PA 처리에 의해 약 32% 수준으로 떨어진 포도당 흡수율은 MPH 처리에 의해 약 199% 수준으로 증가하였다. 또한 장기간 고농도의 포도당(30 mM)에 의해 유도된 당독성 조건에서 MPH는 췌장의 베타세포 INS-1 세포의 생존율을 증가시키고, 대조군에 비해 약 160% 인슐린 mRNA 발현량을 증가시켰다. 이러한 결과에서 MPH는 PTP1B 활성을 저해함으로써 인슐린 신호전달 기작을 활성화하고, 인슐린저항성 환경에서 포도당 흡수를 증진시켜 인슐린저항성을 개선하며, 나아가 고농도 포도당에 의해 유도되는 당독성환경에서 췌장 베타세포를 보호하고 인슐린 mRNA발현량을 정상화할 수 있다는 것을 확인할 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제29권4호
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• pp.249-255
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• 2006

목 적: 양전자방출단층검사(Fluorine-18 2-Deoxy-D-Glucose positron emission tomography : $^{18}F-FDG$ PET)는 가시적 영상분석과 반정량적 섭취계수 분석 방법을 사용하여 폐의 염증성 질환과 폐암을 구별 및 진단하는 데 유용하다. 일반적으로 표준화섭취계수(Standardized Uptake Value : SUV)가 폐 질환의 진단에 사용되지만, 이는 폐 조직에 있어서 반정량적, 정량적 분석을 통한 동적인 정보를 포함하지 않는다. 그러므로, 본 연구는 $^{18}F-FDG$ PET 검사에서 폐 질환의 동적 섭취 분석이 보다 정확한 대상질환의 진단을 유용하게 할 수 있을 것이라는 가정하에 시간-방사능 곡선(Time-Activity Curve: TAC), 표준화섭취계수-동적곡선(Standardized Uptake Value-Dynamic Curve : SUV-DC), 패트락 분석법(Patlak analysis : Glucose Metabolic Rate(MRGlu))을 토대로 얻은 분석방법을 이용하여 진단적 유용성을 평가하였다. 대상 및 방법: 폐 질환을 가진 17명의 환자를 대상을 하여, 각각 60분간 Dynamic $^{18}F-FDG$ PET검사를 시행하였다. 획득한 정보를 통하여 폐질환의 형태를 따라 관심영역(Region of Interest: ROI)를 그린 후, 반정량적 분석인 TAC, SUV-DC와 정량적 분석인 Patlak analysis를 각각의 군에 따라 분석하여 비교 분석하였다. 결 과: Dynamic $^{18}F-FDG$ PET을 통한 분석결과, TAC 형태는 초기 혈류상에서 폐의 염증성 질환과 폐암의 구분이 어려웠으나, 시간이 지날수록 폐암의 곡선이 염증성 질환의 경우보다 확연히 증가하였다. SUV-DC의 경우는 TAC 형태와 거의 유사한 형태를 가졌다. Patlak analysis 분석결과, 대동맥 영역에서는 폐의 염증성 질환이 폐암보다 높은 혈액 방사능을 보였으나 시간이 지남에 따라 염증성 질환의 혈액 방사능이 극히 낮아졌다. 반면, 병변 조직에서는 폐암이 가장 높은 섭취를 보였으며 폐의 염증성 질환은 중간 정도에 머물렀다. 결 론: TAC와 SUV-DC 분석에서 폐암과 폐의 염증성 질환은 각각 고유한 그래프 형태를 띠었으며 Patlak analysis에서 역시 주목할 만한 차이를 보였다. 따라서 이러한 분석법을 토대로 좀더 깊이 있는 연구가 진행된다면 비침습적으로 폐의 질환을 구별하는 데 보다 적절하고 유용한 진단적 정보를 얻을 수 있을 것이다.

• KSBB Journal
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• 제27권6호
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• pp.361-366
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• 2012

We investigated the anti-diabetic activity and enzymatic activity of 24 commercial doenjang samples certified for traditional foods. Twenty four doenjang samples showed the wide ranges in enzymatic activities (protease activities 0-50.45 unit/g, ${\alpha}$-amylase activities 0-675.9 unit/g, ${\beta}$-amylase 13.6-308.6 unit/g), and there were no difference in enzymatic activity by the producing region. To evaluate the potential anti-diabetic activity of 24 doenjang samples, we examined the effect of doenjang methanol extract (DME) on 2-[n-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amyno]-2-deoxy-d-glucose (2-NBDG) uptake. Ten samples among 24 samples significantly stimulated the uptake of 2-NBDG. When the cells were treated with DME at 400 ug/mL, No. 17 and 23 specially stimulated 2-NBDG uptake by 1.23-fold and 1.25-fold, respectively, compared with untreated control cell. And there were no cytotoxicity in the C2C12 cells treated with DME at concentration of 500 ug/mL. Among 24 samples, No. 6, 7, 12, 21 and 24 showed the ${\alpha}$-glucosidase inhibitor activity at concentration of 10 mg/mL; however, they were less effective than acarbose which is a commercial ${\alpha}$-glucosidase inhibitor.

• Nutrition Research and Practice
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• 제11권3호
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• pp.198-205
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• 2017

BACKGROUND/OBJECTIVES: The anti-diabetic activity of pear through inhibition of ${\alpha}-glucosidase$ has been demonstrated. However, little has been reported about the effect of pear on insulin signaling pathway in obesity. The aims of this study are to establish pear pomace 50% ethanol extract (PPE)-induced improvement of insulin sensitivity and characterize its action mechanism in 3T3-L1 cells and high-fat diet (HFD)-fed C57BL/6 mice. MATERIALS/METHODS: Lipid accumulation, monocyte chemoattractant protein-1 (MCP-1) secretion and glucose uptake were measure in 3T3-L1 cells. Mice were fed HFD (60% kcal from fat) and orally ingested PPE once daily for 8 weeks and body weight, homeostasis model assessment of insulin resistance (HOMA-IR), and serum lipids were measured. The expression of proteins involved in insulin signaling pathway was evaluated by western blot assay in 3T3-L1 cells and adipose tissue of mice. RESULTS: In 3T3-L1 cells, without affecting cell viability and lipid accumulation, PPE inhibited MCP-1 secretion, improved glucose uptake, and increased protein expression of phosphorylated insulin receptor substrate 1 [p-IRS-1, ($Tyr^{632})$)], p-Akt, and glucose transporter type 4 (GLUT4). Additionally, in HFD-fed mice, PPE reduced body weight, HOMA-IR, and serum lipids including triglyceride and LDL-cholesterol. Furthermore, in adipose tissue, PPE up-regulated GLUT4 expression and expression ratio of p-IRS-1 ($Tyr^{632})/IRS$, whereas, down-regulated p-IRS-1 ($Ser^{307})/IRS$. CONCLUSIONS: Our results collectively show that PPE improves glucose uptake in 3T3-L1 cells and insulin sensitivity in mice fed a HFD through stimulation of the insulin signaling pathway. Furthermore, PPE-induced improvement of insulin sensitivity was not accompanied with lipid accumulation.

• 미생물학회지
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• 제22권4호
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• pp.243-247
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• 1984

중금속(구리와 카드뮴)이 해양의 표층수와 1m 깊이에서 채취된 미생물군집에 미치는 영향에 관하여 연구되었다. colony 형 성균수와 $^{14}C-glucose$ uptake rate가 배양시간에 따라 각각 측정되었다. 해양에서 채취된 두개의 미생물군집은 서로 상이한 생리적 반응을 나타내었다. 이 결과로서 해양생대체에 토착적인 bacterioneuston population의 존재 가능함을 추정할 수 있다.

• Biomolecules & Therapeutics
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• 제9권4호
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• pp.270-276
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• 2001

Vanadium yeast was prepared by uptaking vanadate in yeast cells. The growth rate of yeast cells was enhanced by 1-5% glucose. While the growth rate of yeast cells was not significantly affected by YEPD containing less than 1mM vanadate, it was completely inhibited by 2.5 mM vanadate. Vanadium uptake in yeast cells was increased with increasing vanadate concentration in growth medium. Vanadate (V) was reduced to vanadyl (IV) in yeast cells associating with macromolecular compounds in cells. Oral administration of vanadium yeast significantly reduced blood glucose levels of streptozotocin treated rats same as vanadate. Vanadate and vanadium yeast similarly increased glucose oxidation in isolated adipocytes. Therefore, it was suggested that vanadium yeast could have an antidiabetic activity potency similar to that of vanadate.

• The Korean Journal of Physiology
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• 제29권2호
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• pp.191-202
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• 1995

The purpose of this study was to compare effects of insulin and IGFs on growth, apical membrane enzyme activities and membrane transport systems of primary cultured rabbit kidney proximal tubule cells. Results were as follows: 1. Insulin and IGF-I produced significant growth stimulatory effects at $5{\times}10^{-10}M.\;IGF-II(5×10^{-10}\;M)$ did not stimulate significant cell growth. 2. Insulin stimulated the phosphorylation of a 97 KD protein. It was difficult to determine whether this band represents insulin and/or the IGF-I receptor. 3. The activities of apical membrane enzymes (alkaline phosphatase, leucine aminopeptidase, and ${\gamma}-glutamyl \;transpeptidase)$ were observed to be diminished after the cells were placed in the culture environment. 4. The uptake of ${\alpha}-MG,$ Pi and Na was significantly increased in cells incubated with insulin or IGF-I, IGF-II had no effect on the uptake of these substrates. 5. Na-pump activity, as assayed by Rb uptake, was significantly increased in cells treated with insulin or IGFs. In conclusion, insulin and IGF-I exert stimulatory effects on growth and membrane transporter(glucose, Na, Pi, and Na-pump) activities in primary cultured rabbit kidney proximal tubule cells. IGF-II had no effect on cell growth and membrane transporter(glucose, Na and Pi) activities.

• 생명과학회지
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• 제24권1호
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• pp.86-91
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• 2014

Trichoplusia ni (T. ni) 세포는 사람 당 수송체를 이성질적으로 많은 양 생산하려 할 때 유용하게 사용되는, baculovirus 발현 시스템의 숙주세포로서 이용된다. 그러나 T. ni 세포에 존재하는 내재된 당 수송체의 높은 활동은, 발현된 외재적 당 수송체의 수송활성과 같은 직접적 증거 제시에 장애가 된다. 뿐만 아니라 곤충세포에 내재하는 당 수송체계의 특성에 대해서는 밝혀진 바가 거의 없다. 그래서 본 연구에서는 baculovirus 발현 시스템을 보다 잘 활용하기 위해 T. ni 세포의 2dGlc기질 수송에 D-fructose가 미치는 영향을 살펴 보았으며, T. ni 세포에 발현된 사람 당 수송체의 생물학적 활성을 보다 용이하게 검증하기 위해 발현된 수송체를 [$^3H$] cytochalasin B를 이용하여 photolabelling 하였다. 우선 감염되지 않은 세포와 recombinant AcMPV-GTL 감염시킨 T. ni 세포의 2dGlc uptake를 300 mM D-fructose가 있을 때와 없을 때, 그리고 $20{\mu}M$ cytochalasin B가 있을 때와 없을 때의 상황에서 살펴보았다. 감염되지 않은 세포에서의 육탄당 uptake는 D-fructose에 의해 강력하게 억제 되었으나 cytochalasin B에 의해서는 단지 미미한 억제 효과만을 보여주었다. 흥미롭게도 AcMPV-GTL 바이러스 감염된 T. ni 세포에서는 비록 2dGlc uptake율은 감염되지 않은 세포와 비교해 다소 낮았지만 육탄당 수송 억제 반응은 근본적으로 동일함을 보여 주었다. 또한 [$^3H$] cytochalasin B를 이용한 발현단백질 photolabelling에서는, L-glucose가 존재하는 상황 하에만 하나의 날카롭게 표지된 peak가, 바이러스 감염된 세포에서 관찰되었다. 감염되지 않은 세포에서는 이러한 peak는 관찰되지 않았다. 게다가 D-glucose 존재 하에서는 발현된 단백질의 photolabelling이 완전히 억제되어짐을 보여주어, labelling의 입체선택성(stereoselectivity)을 입증하였다.

• 약학회지
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• 제40권6호
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• pp.705-712
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• 1996

We have previously shown that determination of glucose uptake using ${\alpha}$-methylglucose(${\alpha}$-MG) is very sensitive and rapid parameter for the assessment of loss of cellular fu nction in renal cell line($LLC-PK_1$). The present study was designed to elucidate the mechanism of inhibition of ${\alpha}$-MG uptake and the intracellular site of toxic action of cisplatin(CIS). $LLC-PK_1$ cells were exposed to various concentrations(5 ${\mu}$M-l00 ${\mu}$M) of CIS for 5 hrs or 24 hrs and ${\alpha}$-MG uptake was determined. Mitochondrial function was evaluated by measuring intracellular ATP content and MTT reduction. The activities of marker enzymes for the basolateral membrane(Na$^+$-K$^+$ ATPase) and brush border membrane (alkaline phosphatase: ALP) were also measured. CIS treatment significantly inhibited the ${\alpha}$-MG uptake in a time- and dose-dependent manner above 25 ${\mu}$M for 5 hrs. Intracellular ATP content and MTT reduction were affected by 24 hr-treatment of 50 ${\mu}$M CIS. The activities of Na$^+$-K$^+$ ATPase and ALP were significantly decreased at 10 ${\mu}$M and 5 ${\mu}$M of CIS for 24 hrs, respectively. The incubation with CIS for 5 hrs had no effects on the intracellular ATP content, MTT reduction and the activities of marker enzymes up to 100 ${\mu}$M. These results partly indicate that inhibition of ${\alpha}$-MG uptake by CIS may not be attributed to the disturbance of mitochondrial function or inhibition of the activity of Na$^+$-K$^+$ ATPase and can be resulted from direct effect of CIS on the Na$^+$/glucose cotransporter in brush border membrane. This study shows that additional mechanistic information, indicating the intracellular site of nephrotoxic action, can be gained by coupling the ${\alpha}$-MG uptake and ATP content or the activity of Na$^+$-K$^+$ ATPase.