• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.4
• /
• pp.1823-1829
• /
• 2014

Aims: Much evidence suggests that increased glucose metabolism in tumor cells might contribute to the development of acquired chemoresistance. However, the molecular mechanisms are not fully clear. Therefore, we investigated a possible correlation of mRNA expression of HIF-$1{\alpha}$ and GLUT1 with chemoresistance in acute myeloid leukemia (AML). Methods: Bone marrow samples were obtained from newly diagnosed and relapsed AML (M3 exclusion) cases. RNA interference with short hairpin RNA (shRNA) was used to stably silence GLUT1 or HIF-$1{\alpha}$ gene expression in an AML cell line and HIF-$1{\alpha}$ and GLUT1 mRNA expression was measured by real-time quantitative polymerase chain reaction assay (qPCR). Results: High levels of HIF-$1{\alpha}$ and GLUT1 were associated with poor responsiveness to chemotherapy in AML. Down-regulation of the expression of GLUT1 by RNA interference obviously sensitized drug-resistant HL-60/ADR cells to adriamycin (ADR) in vitro, comparable with RNA interference for the HIF-$1{\alpha}$ gene. Conclusions: Our data revealed that over-expression of HIF-$1{\alpha}$ and GLUT1 might play a role in the chemoresistance of AML. GLUT1 might be a potential target to reverse such drug resistance.

• Animal Bioscience
• /
• v.34 no.4
• /
• pp.670-679
• /
• 2021

Objective: Glucose transporter 9 (GLUT9) is a uric acid transporter that is associated with uric absorption in mice and humans; but it is unknown whether GLUT9 involves in chicken uric acid regulation. This experiment aimed to investigate the chicken GLUT9 expression and serum uric acid (SUA) level. Methods: Sixty chickens were divided into 4 groups (n = 15): a control group (NC); a sulfonamide-treated group (SD) supplemented with sulfamonomethoxine sodium via drinking water (8 mg/L); a fishmeal group (FM) supplemented with 16% fishmeal in diet; and a uric acid-injection group (IU), where uric acid (250 mg/kg) was intraperitoneally injected once a day. The serum was collected weekly to detect the SUA level. Liver, kidney, jejunum, and ileum tissues were collected to detect the GLUT9 mRNA and protein expression. Results: The results showed in the SD and IU groups, the SUA level increased and GLUT9 expression increased in the liver, but decreased in the kidney, jejunum, and ileum. In the FM group, the SUA level decreased slightly and GLUT9 expression increased in the kidney, but decreased in the liver, jejunum, and ileum. Correlation analysis revealed that liver GLUT9 expression correlated positively, and renal GLUT9 expression correlated negatively with the SUA level. Conclusion: These results demonstrate that there may be a feedback regulation of GLUT9 in the chicken liver and kidney to maintain the SUA balance; however, the underlying mechanism needs to be investigated in future studies.

• Journal of Chest Surgery
• /
• v.43 no.5
• /
• pp.506-512
• /
• 2010

Background: This study was designed to evaluate the FDG uptake ratio of mediastinal node and primary tumors using integrated PET/CT imaging combined with Glut-1 expression of the primary tumor in order to predict the N2 status more accurately in NSCLC patients. Material and Method: Patients who underwent integrated PET/CT scanning with a detectable mSUV for both primary tumors and mediastinal lymph nodes were eligible for this study. The FDG uptake ratio between the mediastinal node and the primary tumor was calculated. Result: The average mSUV of primary tumors and mediastinal nodes were, respectively, $7.4{\pm}2.2$ and $4.2{\pm}2.2$ in N2-positive patients and $7.6{\pm}3.7$ and $2.8{\pm}6.9$ in N2-negative patients. The mean FDG uptake ratio of mediastinal node to primary tumor were $0.58{\pm}0.23$ for malignant N2 lymph nodes and $0.45{\pm}0.20$ for benign lymph nodes (p<0.05). Models which combined Glut-1 expression with an FDG ratio have better diagnostic power than models that use the FDG uptake ratio alone. Conclusion: In some patients with a previous history of pulmonary tuberculosis or other inflammatory lung diseases, an FDG uptake ratio combined with Glut-1 expression may be useful in diagnosing mediastinal node metastasis more exactly.

• Journal of Nutrition and Health
• /
• v.54 no.6
• /
• pp.603-617
• /
• 2021

Purpose: This study was carried out to investigate the effect of amaranth seed extracts on glycemic regulation in HepG2 cells. The 80% ethanol extracts of amaranth seeds were used to evaluate α-amylase and α-glucosidase activities, cell viability, glucose uptake and messenger RNA (mRNA) expression levels of acetyl-CoA carboxylase (ACC), glucose transporter (GLUT)-2, GLUT-4, insulin receptor substrate (IRS)-1 and IRS-2. Methods: The samples were prepared and divided into 4 groups, including germinated black amaranth (GBA), black amaranth (BA), germinated yellow amaranth (GYA) and yellow amaranth (YA). Glucose hydrolytic enzyme, α-amylase and α-glucosidase activities were examined using a proper protocol. In addition, cell viability was measured by MTT assay. Glucose uptake in cells was measured using an assay kit. The mRNA expression levels of ACC, GLUT-2, GLUT-4, IRS-1 and IRS-2 were measured by reverse transcription polymerase chain reaction. Results: The inhibitory activities of α-amylase and α-glucosidase were highly observed in GBA, followed by BA, GYA and YA. Similar results were observed for glucose. The GBA effect was similar compared to the positive control group. The mRNA expression levels of ACC, GLUT-2, GLUT-4, IRS-1, and IRS-2 were significantly increased. The potential hypoglycemic effects of amaranth seed extracts were observed due to the increase in glucose metabolic enzyme activity, and glucose uptake was mediated through the upregulation of ACC, GLUT-2, GLUT-4, IRS-1, and IRS-2 expression levels. Conclusion: Our findings suggest that the amaranth seed is a potential candidate to prevent a diabetes. The present study demonstrated the possibility of using amaranth seeds, especially GBA and BA for glycemic control.

• Journal of Life Science
• /
• v.17 no.6 s.86
• /
• pp.859-866
• /
• 2007

The main objective of this study was to investigate the effects of exercise on serum insulin and leptin levels and GLUT-4 and VAMP-2 in skeletal muscles from the pregnant rats. F344 rats were randomly divided into four groups (n = 15 in each group): control group (CG), pregnant group (PG), pregnant running group (PR), and pregnant swimming group (PS). From the 15th day of pregnancy, animals in the running group were forced to run on treadmill for 30 min with a light intensity, while those in the swimming group were forced to swim in swimming pool for 10 min once a day for 6 consecutive days. The present result demonstrated that in pregnant rat group, serum insulin levels significantly in-creased and leptin levels significantly decreased. Skeletal GLUT-4 and VAMP-2 protein expression was significantly decreased in pregnant rats compared to non-pregnant rats. However, matenal running during gestational period alleviated pregnancy-induced changes in plasma insulin and leptin levels, and it significantly enhanced skeletal GLUT-4 and VAMP-2 protein expression. From those results, it can be suggested that running exercise during gestational period may improve glycemic control by up-regulating GLUT-4 and VAMP-2 protein expression.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1297-1304
• /
• 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.

• Journal of Nutrition and Health
• /
• v.33 no.7
• /
• pp.712-716
• /
• 2000

The Purpose of this study is to investigate the effect of soluble dietary fiber psyllium on insulin sensitivity and skeletal muscle glucose transporter 4(GLUT4) protein expression in stroke-prone hypertensive rats(SHRSP) fed a high-fat diet containing 5% of psyllium or cellulose from five to nine weeks of age. Obtained results were as follows : (1) In the psyllium diet group fasting plasma glucose level was significantly reduced and glucose levels upon oral glucose tolerance test were significantly lower than cellulose diet group at 30 min(p<0.05) and 60 min(p<0.01) (2) Skeletal muscle GLUT4 contents were significantly increased in the soleus(slow twitch) and extensor digitorum longus(fast twitch) muscle of psyllium diet group. (3) However there was no difference in insulin levels in the fasting and oral glucose tolerance test. These results indicated that psyllium diet improves peripheral insulin sensitivity but not insulin secretion. In conclusion our present finding suggest that soluble fiber diet is effective to increase insulin sensitivity in SHRSP. From these results it was suggested that soluble dietary fiber supplementation effectively prevents insulin resistance.

• The Korean Journal of Physiology and Pharmacology
• /
• v.5 no.2
• /
• pp.183-188
• /
• 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.

• Journal of Nutrition and Health
• /
• v.39 no.4
• /
• pp.323-330
• /
• 2006

Peripheral insulin resistance in obese/type II diabetes animals results from an impairment of insulin-stimulated glucose uptake into skeletal muscle. Insulin stimulate the translocation of GLUT4 from intracellular location to the plasma membrane. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) is implicated in mediation of fusion of GLUT4-containing vesicle with the plasma membrane. Present study investigated regulatory effects of Rhodiola sachalinensis administration and exercise training on the expression of GLUT4 protein and SNAREs protein in skeletal muscles of obese Zucker rats. Experimental animals were randomly assigned into one of five groups ; lean control(LN), obese control(OB), exercise-treated(EXE), Rhodiola sachalinensis-treated(Rho), combine of Rho & EXE (Rho-EXE). All animals of exercise training (EXE, Rho-EXE) performed treadmill running for 8 weeks, and animals of Rho groups (Rho, Rho-EXE) were dosed daily by gastric gavage during the same period. After experiment, blood were taken for analyses of glucose, insulin, and lipids levels. Mitochondrial oxidative enzyme (citrate synthase, CS ; $\beta$-hydroxyacyl-CoA dehydrogenase, $\beta$-HAD) activity were analysed. Skeletal muscles were dissected out for analyses of proteins (GLUT4, VAMP2, syntaxin4, SNAP23). Results are as follows. Exercise and/or Rhodiola sachalinensis administration significantly reduced body weight and improved blood lipids (TG, FFA), and increased insulin sensitivity. Endurance exercise significantly increased the activity of mitochondrial enzymes and the expression of GLUT4 protein, however, administration of Rhodiola sachalinensis did not affect them. The effect of exercise and/or Rhodiola sachalinensis administration on the expression of SNARE proteins was unclear. Our study suggested that improvement insulin sensitivity by exercise and/or Rhodiola sachalinensis administration in obese Zucker rats is independent of expression of SNARE proteins.

• Korean Journal of Exercise Nutrition
• /
• v.13 no.2
• /
• pp.131-140
• /
• 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.