• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.450-455
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• 2004

A reducing glucose-carrying polymer, called poly [3-O-(4'-vinylbenzyl)-D-glucose］(PVG), was interacted with HepG2 cells including a type-l glucose transporter (GLUT-1) on the cell membrane. The cooperative interaction between a number of GLUT-1s and a number of reducing 3-O-methyl-D-glucose moieties on the PVG polymer chain was found to be responsible for the increase in the interaction with HepG2 cells. The affinity between the cells and the PVG was studied using RITC-labeled glycopolymers. The specific interaction between the GLUT-1 on HepG2 cells and the PVG polymer carrying reducing glucose moieties was suppressed by the inhibitors, phloretin, phloridzin, and cytochalasin B. Direct observation by confocal laser microscopy with the use of RITC-labeled PVG and pretreatment of HepG2 cells with the inhibitors demonstrated that the cells interacted with the soluble form of the PVG polymer via GLUT-1, while fluorescence labeling of the cell surface was prevented after pretreatment with the inhibitors of GLUT-1.

• 생명과학회지
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• 제15권1호
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• pp.87-93
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• 2005

본 연구에서는 Streptozotocin-유발 당뇨 쥐를 대상으로 8주 동안 운동 강도에 따른 혈당, 인슐린, 골격근 내 GLUT-4 발현 량과 GRP-78 발현량 변화를 관찰함으로써 당뇨 쥐의 혈당을 낮추는데 효과적인 운동 강도는 무엇이며, 기전적인 원인은 무엇인지를 밝히고자 실시되었다. 본 연구에서 Streptozotocin으로 당뇨를 유발시킨 흰쥐를 대상으로 운동 강도 처치에 따른 GLUT-4발현 량을 비교한 결과, 기본적으로 당뇨가 유발된 흰쥐의 GLUT-4 발현 량은 정상 쥐에 비해 현저하게 감소하는 것을 볼 수 있었다. 이중 8주 동안 저강도 운동 수행 한 쥐들의 경우는 정상 쥐 수준에 가까운 발현 량을 관찰 할 수 있었으며, 흰쥐 가자미 근 내 GRP-78 발현 량은 당뇨 유발 쥐의 경우 정상 쥐의 유의하게 증가한 것을 관찰할 수 있었고, 저강도 운동을 수행한 집단에서의 GRP-78 발현 량은 정상 흰쥐에서 발현되는 양에 비해 유의하게 높은 수준을 보이기는 했지만 당뇨 유발 대조군과 고강도 운동 군에 비해서는 유의하게 낮은 수준으로 나타났다. 결론적으로 저강도의 운동은 당뇨 질환자의 혈당을 낮추는 데 가장 효과적인 운동이라 할 수 있으며, 이러한 결과의 기전적인 원인은 저강도의 운동이 근육 내 GLUT-4의 증가로 세포내 당 유입을 촉진시킴으로 해서 나타난 사실이라 생각되며 이 같은 사실은 GRP-78의 발현 량의 감소로 확인할 수 있었다.

• 운동영양학회지
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• 제13권1호
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• pp.1-7
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• 2009

It has been shown that both caloric restriction and exercise, enhances glucose uptake through translocation of GLUT-4 protein. It remains unclear how exercise and caloric restriction affect the changes in VAMP (vesicle-associated membrane protein) in skeletal muscle and GLUT-2 in liver. This study investigated the effects of exercise training and caloric restriction on the expressions of glucose transport relating proteins in muscle and liver tissues in diabetic rats. Forty male Sprague-Dawley rats (250±10 g; 8 week in age) were assigned equally to four different groups; control (C), exercise only (E), dietary restriction only (D) and dietary restriction and exercise (DE). Daily food consumption was monitored to establish baseline intake. Both C and E groups consumed baseline food intake while D and DE groups were provided with only 60% of baseline total food intake. Forty-eight hours after intraperitoneal injection of STZ (50 mg/kg), diabetes was confirmed (8-hr fasting blood glucose levels ≥300 mg/dl). Rats in the E and DE groups exercised on a motorized treadmill for 30 min/d, 5 days/week for 4 weeks (5 min running at 3 m/min, 0% grade; 8 m/min for the next 5min, and then 15 m/min for 20 min). Rats were sacrificed 48 hrs after the last bout of exercise. Soleus muscle and liver were extracted to analyze for GLUT-4, VAMP-2, and GLUT-2, respectively. All variables were analyzed using the Western Blotting technique. All values were expressed as optical volume measured by optical density. A Two-way ANOVA was used to examine the difference between groups and applied Duncan's test for post-hoc. No significant differences in GLUT-2 expression were found among groups. However, E (280133±13228 arbitrary units{AU}) and DE (268833±14424 AU) groups showed significantly higher (p<.001) levels of GLUT-4 as compared with C (34461±2099 AU) and D groups (27847±703 AU). VAMP-2 protein expression increased (p<.001) in E (184137±7803 AU) and DE (189800±10856 AU) groups as compared to C (74201±8296AU) and D (72967±863 AU) groups. These results suggest that either exercise with or without caloric restriction increases the up-regulation of GLUT-4 and VAMP-2 in skeletal muscle of diabetic rats. However, GLUT-2 protein in liver was not affected by either exercise or exercise with caloric restriction.

• 생명과학회지
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• 제31권1호
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• pp.1-9
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• 2021

본 연구는 갈조류 유래 물질인 후코이단이 인슐린 민감성을 증진시키는지를 규명하기 위하여 3T3-L1 지방세포에서 포도당 흡수에 미치는 후코이단의 영향을 측정하고 그 작용기전을 조사하였다. 후코이단은 지방세포에서 포도당 흡수를 유의하게 증가시켰으며 이는 PM-GLUT4의 발현 증가와 관련이 있음을 관찰하였다. 후코이단은 인슐린 신호전달 경로에서 PI3K의 활성화 및 pIRS1tyr, Akt, PKCλ/ζ의 인산화를 대조군에 비해 유의하게 증가시켰다. 또한, AMPK의 활성화를 나타내는 pAMPK 수준이 유의하게 증가하였다. 이들 PI3K 및 AMPK 활성화는 포도당 수송체인 GLUT4를 세포막으로 이동시켰으며 이로 인하여 PM-GLUT4의 발현이 증가되고 포도당 흡수가 촉진되었다. 후코이단에 의한 PI3K 및 AMPK 경로의 활성화를 증명하기 위해, PI3K 억제제인 Wortmannin과 AMPK의 억제제인 Compound C를 사용하여 이들 처리에 의한 포도당 흡수능과 PM-GLUT4의 발현을 측정한 결과 이들의 발현이 유의하게 저해되었다. 따라서 후코이단은 3T3-L1 지방세포에서 PI3K 및 AMPK 경로를 활성화시킴으로써 인슐린 민감성을 증진하고 포도당 흡수를 촉진시킬 수 있음을 나타내었다.

• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.183-188
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• 2001

To elucidate antidiabetic effect and mechanism(s) of acarbose in a polygenic spontaneous hyperglycemic and hyperinsulinemic diabetic animal model, $KKA^y$ mice, acarbose was administered orally for 4 weeks and effects on body weight, plasma glucose and insulin levels, genetic expressions of intestinal sucrase-isomaltase (SI), sodium-glucose cotransporter (sGLT1) and glucose transporter in quadriceps muscle (GLUT4) were examined in this study. Although no differences in body weight were detected between control and acarbose-treated groups, plasma glucose level in acarbose-treated group was markedly reduced as compared to the control. In the mechanism study, acarbose downregulated the SI and SGLT1 gene expressions, and upregulated the GLUT4 mRNA and protein expressions when compared to the control group. In conclusion, the data obtained strongly implicate that acarbose can prevent the hyperglycemia in $KKA^y$ mice possibly through blocking intestinal glucose absorption by downregulations of SI and sGLT1 mRNA expressions, and upregulation of skeletal muscle GLUT4 mRNA and protein expressions.

• Asian Pacific Journal of Cancer Prevention
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• 제17권1호
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• pp.147-151
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• 2016

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity and some of these have been documented in association or preceded by oral epithelial dysplasia (OED). Aggressive cancers with fast growth have demonstrated overexpression of some glucose transporters (GLUTs). Thus, the aim of this study was to analyze the immunohistochemical expression of the glucose transporter, GLUT-1, in OEDs and OSCCs, seeking to better elucidate the biological behavior of neoplasias. Fifteen cases were selected this research of both lesions. Five areas were analyzed from each case by counting the percentage of positive cells at 400x magnification. Immunoreactivity of GLUT-1 was observed in 100% of the samples ranging from 54.2% to 86.2% for the OSCC and 73.9% to 97.4% for the OED. Statistical test revealed that there was greater overexpression of GLUT-1 in OED than the OSCC (p=0.01). It is believed the high expression of GLUT-1 may reflect the involvement of GLUT-1 in early stages of oral carcinogenesis.

• 생명과학회지
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• 제14권5호
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• pp.741-746
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• 2004

본 연구는 운동강도 차이에 따른 카페인 구강 투여가 STZ-유발 당뇨 쥐 가자미근에서 GLUT-4와 GRP-78 단백질 발현에 미치는 영향을 규명하기 위하여 F344계 수컷 횐쥐를 무작위 표본추출에 의하여 당뇨유발군(n=6), 당뇨유발-카페인 투여군(n=6), 당뇨유발-카페인투여 저강도운동군(n=6), 당뇨유발-카페인투여 중강도운동군(n=6), 그리고 당뇨유발-카페인투여 고강도 운동군(n=6)으로 분류하였다. 저강도 운동은 트레드밀 경사도 0%에서 8 m/min 속도로, 중강도 운동은 트레드밀 경사도 0%에서 16 m/min 속도로, 고강도운동은 트레드밀 경사도 0%에서 25 m/min속도로 30분간 1회 운동을 실시하였다. GLUT4단백질 발현은 당뇨군에 비해서 당뇨유발군-카페인 투여군과 당뇨유발-카페인투여 저강도 운동군에서 차이가 없었으며, 당뇨유발-카페인투석 중강도 운동군에서는 다소 감소하였으나 당뇨유발-카페인투여 고강도 운동군에서 증가하였다. GRP-78 단백질 발현은 당뇨군에 비해서 당뇨유발-카페인투여 저강도 운동군, 당뇨유발-카페인투여 중강도 운동군, 그리고 당뇨유발-카페인투석 고강도 운동군에서 감소하였으나, 당뇨유발-카페인 투여군에서는 다소 증가한 것으로 나타났다 고강도 일회성 운동이 인슐린 민감도를 개선시켜 인슐린 요구량을 낮추는데 이러한 효과는 내형질세망에서 세포막으로의 GLUT-4 단백질의 전이와 GLUT-4 단백질 양의 증가 때문이다. 운동군에서의 GRP-78 단백질이 감소된 기전은 정확히 밝힐 수는 없지만, 카페인으로 인한 지질 동원이 운동 시 작업근의 세포에 많은 에너지를 공급하여 세포가 받는 스트레스를 완화시켜 주었기 때문이라고 추측된다.

• Tuberculosis and Respiratory Diseases
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• 제45권4호
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• pp.760-765
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• 1998

연구배경: 암세포에서 포도당의 유입이 증가되어 있다는 사실이 오래 전부터 알려져 왔고 이런 현상을 이용하여 FDG-PET 영상이 암의 진단에 이용되고 있다. 그러나, 암세포에서 포도당 유입이 증가하는 기전에 대해서는 모르고 있다. 최근, 여러 연구에서 소화기계의 악성종양과 두경부종양에서 포도당 운반체의 mRNA 의 존재가 증명되었고, 포도당 운반체가 암세포에서의 포도당 유입 증가와 관련이 있을 가능성을 시사하였다. 폐암에서도 포도당대사가 항진되어 있다. 저자등은 폐암에서의 포도당 유입이 증가하는 기전에 대해 알아 보기 위하여 사람 폐암세포주에서 포도당 mRNA의 발현여부를 확인하였다. 방 법: 15종의 사람 폐암 세포주와 불멸화시킨 기관지 상피세포주에서 total RNA를 추출하였다. $20{\mu}g$의 total RNA를 전기영동시킨후, 포도당 운반체 1형과 3 형에 대한 cDNA를 probe로 Northern blot analysis를 시행하였다. 결 과: 14종의 사람 폐암 세포주중에서 13종에서 포도당 운반체 1형의 mRNA 발현을 확인하였고, 14종의 사람 폐암 세포주중에서 10종에서 포도당 운반체 3형의 mRNA 발현을 확인하였다. 불멸화시킨 기관지 상피세포주의 포도당 운반체 1형의 mRNA 발현을 확인할 수 있었고 3형의 mRNA 발현은 확인할 수 없었다. 결 론: 폐암에서 포도당 대사의 증가는 포도당 운반체 1형과 3형의 발현과 관련이 있을 것으로 사료된다.

• 운동영양학회지
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• 제13권2호
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• pp.131-140
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• 2009

The aim of this study was to investigate the expression of PPAR-α, -β/δ, -γ, PGC-1α, GLUT-4 and p-AMPK-α₂ protein in the skeletal muscle of diabetic induced-rats by endurance training combined with rosiglitazone. The expression of PPAR-α, -β/δ, -γ, PGC-1α, GLUT-4 and p-AMPK-α₂ protein in red and white gastrocnemius by western blotting. The body weight was higher in diabetic induced-rats compared to the normal rats and after the treatment of exercise combined with rosiglitazone was significantly reduced in the all group. The levels of blood glucose was higher in diabetic induced-rats compared to the normal rats and after the treatment of exercise combined with rosiglitazone was significantly reduced in the all group. The expression of PPAR-α, -γ, PGC-1α in skeletal muscle of diabetic induced-rats were increased all groups and increased significantly in the group with exercise combined with rosiglitazone. The expression of GLUT-4 and p-AMPK-α₂ protein in the skeletal muscle of diabetic induced-rats were increased all groups and increased significantly in the group with exercise combined with rosiglitazoneI. These results suggest that exercise training and rosiglitazone may act as complementary therapies for the treatment of insulin rasistance.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1297-1304
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• 2007

We conducted a series of investigations in order to elucidate role of nutritional status in regulating GLUT expression and energy metabolism in porcine muscle. Firstly, the role of mild undernutrition in regulating muscle GLUT gene expression and function was studied in growing pigs (3 wk of age) on a high (H) or low (L) food intake (H = 2L) at $35^{\circ}C$ or $26^{\circ}C$. Low food intake selectively upregulates GLUT1 and GLUT4 gene expression; mRNA levels were elevated in longissimus dorsi (L. dorsi) and rhomboideus muscles but not in diaphragm or cardiac muscles. Our next step was to determine whether dietary lysine, a major primary limiting amino acid in diets for pigs, affects muscle GLUT4 expression. Pigs of 6 wk of age were pair-fed a control or low lysine (LL) diet. The control diet contained optimal amounts of all essential amino acids, including 1.15% lysine. The LL diet was similar but contained only 0.70% lysine. GLUT4 mRNA expression was upregulated by the LL diet in L. dorsi and rhomboideus muscles, whereas that in cardiac muscle was unaffected. GLUT4 protein abundance was also higher in rhomboideus muscle of animals on the LL diet. We conducted another investigation in order to elucidate effects of the LL diet on post-GLUT4 glucose metabolism. Activity of hexokinase was unaffected by dietary lysine levels while that of citrate synthase was higher both in L. dorsi and rhomboideus muscles of pigs fed on the LL diet. Glucose 6-phosphate content was higher in L. dorsi msucle in the LL group. Glycogen content was higher both in L. dorsi and rhomboideus muscles in the LL group. Further, we determined the effects of dietary lysine levels on accumulation of intramuscular fat (IMF) in L. dorsi muscle of finishing pigs. A low lysine diet (lysine content was 0.40%) meeting approximately 70% of the requirement of lysine was given to finishing pigs for two months. IMF contents in L. dorsi of the pigs given the low lysine diet were twice higher than those of the pigs fed on a control diet (lysine content was 0.65%). Finally, we proved that a well known effect of breadcrumbs feeding to enhance IMF of finishing pigs could be attributed to shortage of amino acids in diets including breadcrumbs.