Time-dependent physiological regulation of ovine placental GLUT-3 glucose transporter protein

2000 ◽  
Vol 279 (6) ◽  
pp. R2252-R2261 ◽  
Author(s):  
Utpala G. Das ◽  
Jing He ◽  
Richard A. Ehrhardt ◽  
William W. Hay ◽  
Sherin U. Devaskar

We immunolocalized the GLUT-3 glucose transporter isoform versus GLUT-1 in the late-gestation epitheliochorial ovine placenta, and we examined the effect of chronic maternal hyperglycemia and hypoglycemia on placental GLUT-3 concentrations. GLUT-3 was limited to the apical surface of the trophoectoderm, whereas GLUT-1 was on the basolateral and apical surfaces of this cell layer and in the epithelial cells lining the placental uterine glands. GLUT-3 concentrations declined at 17–20 days of chronic hyperglycemia ( P < 0.05), associated with increased uterine and uteroplacental net glucose uptake rate, but a normal fetal glucose uptake rate was observed. Chronic hypoglycemia did not change GLUT-3 concentrations, although uterine, uteroplacental, and fetal net glucose uptake rates were decreased. Thus maternal hyperglycemia causes a time-dependent decline in the entire placental glucose transporter pool (GLUT-1 and GLUT-3). In contrast, maternal hypoglycemia decreases GLUT-1 but not GLUT-3, resulting in a relatively increased GLUT-3 contribution to the placental glucose transporter pool, which could maintain glucose delivery to the placenta relative to the fetus when maternal glucose is low.

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Hyun Jin Baek ◽  
Yong Joon Jeong ◽  
Jeong Eun Kwon ◽  
Jong Sung Ra ◽  
Sung Ryul Lee ◽  
...  

The extract of the Momordica charantia fruit (MCE) is recognized as an alternative treatment for diabetes. The extract of Ligularia fischeri leaves (LFE) is traditionally used as a folk medicine for treating inflammatory diseases in Korea as well. In this study, we investigated the synergistic effect of MCE combined with LFE on antihyperglycemic and antihyperlipidemic potentials. Based on the α-glucosidase inhibitory effect and promotion of adipocyte differentiation in the 3T3-L1 cell line, the MLM was prepared with MCE:LFE (8:2 weight:weight). MLM showed the synergistic effects in the promotion of the glucose uptake rate, suppression of dipeptidyl peptidase-4 (DPP-4) mRNA expression, upregulation of an insulin receptor substrate and glucose transporter type-4 expression, and an increase in insulin-associated signaling in C2C12 cells. In addition, the efficacy of peroxisome proliferator-activated receptor-γ agonism and glucose uptake rate by MLM supplementation was significantly enhanced in vitro. Then, the antihyperglycemic and antihyperlipidemic effects of MCE, LFE, and MLM at the dose of 50, 100, and 200 mg/kg/day (n = 6 per each group) were determined in streptozotocin (STZ)-insulted mice fed an atherogenic diet (ATH) for 4 weeks. In addition, MLM (50, 100, and 200 mg/kg/day, n = 5 per each group) was supplemented in ATH-fed db/db mice for 10 weeks. Compared with MCE or LFE alone, MLM supplementation led to a more significant reduction of glucose levels in both STZ/ATH and db/db/ATH mice as well as lowered lipid profiles in STZ/ATH mice. In addition, the stimulation of islet of Langerhans regeneration was more pronounced by MLM supplementation in both mice models. In conclusion, antihyperglycemic and antihyperlipidemic effects were strengthened by the combined extracts of L. fischeri and M. charantia (MLM) in diabetes-mimicking mice.


Circulation ◽  
1999 ◽  
Vol 100 (suppl_2) ◽  
Author(s):  
Ingeborg Friehs ◽  
Adrian M. Moran ◽  
Christof Stamm ◽  
Steven D. Colan ◽  
Koh Takeuchi ◽  
...  

Background —Severe hypertrophy and heart failure are important risk factors in cardiac surgery. Early adaptive changes in hypertrophy include increased ventricular mass-to-cavity volume ratio (M/V ratio) and increased dependence on glucose for energy metabolism. However, glucose uptake is decreased in the late stages of hypertrophy when ventricular dilatation and failure are present. We hypothesized that impaired glucose uptake would be evident early in the progression of hypertrophy and associated with the onset of ventricular dilatation. Methods and Results —Ten-day-old rabbits underwent banding of the descending aorta. Development of hypertrophy was followed by transthoracic echocardiography to measure left ventricular M/V ratio. Glucose uptake rate, as determined by 31 P-nuclear magnetic resonance spectroscopy measuring 2-deoxyglucose conversion to 2-deoxyglucose-6-phosphate, was measured in isolated perfused hearts obtained from banded rabbits when M/V ratio had increased by 15% from baseline (compensated hypertrophy) and by 30% from baseline (early-decompensated hypertrophy). In age-matched control animals, the rate of glucose uptake was 0.61±0.08 μmol · g of wet weight −1 · 30 min −1 (mean±SEM). With a 15% M/V ratio increase, glucose uptake rate remained at control levels (0.6±0.05 μmol · g of wet weight −1 · 30 min −1 ), compared with hearts with 30% increased M/V ratios, where glucose uptake was significantly lower (0.42±0.05 μmol · g of wet weight −1 · 30 min −1 ; P ≤0.05). Glucose transporter protein expression was the same in all groups. Conclusions —Glucose uptake rate is maintained during compensated hypertrophy. However, coinciding with severe hypertrophy, preceding ventricular dilatation, and glucose transporter protein downregulation, glucose uptake is significantly decreased. Because of the increased dependence of the hypertrophied hearts on glucose use, we speculate that this impairment may be a contributing factor in the progression to failure.


1998 ◽  
Vol 274 (2) ◽  
pp. R339-R347 ◽  
Author(s):  
Utpala G. Das ◽  
H. Farouk Sadiq ◽  
Michael J. Soares ◽  
William W. Hay ◽  
Sherin U. Devaskar

To examine the in vivo and in vitro time-dependent effects of glucose on placental glucose transporter (GLUT-1) protein levels, we employed Western blot analysis using placenta from the short-term streptozotocin-induced diabetic pregnancy (STZ-D), uterine artery ligation-intrauterine growth restriction (IUGR) rat models, pregnant sheep exposed to chronic maternal glucose and insulin infusions, and the HRP.1 rat trophoblastic cell line exposed to differing concentrations of glucose. In the rat, 6 days of STZ-D with maternal and fetal hyperglycemia caused no substantive change, whereas 72 h of IUGR with fetal hypoglycemia and ischemic hypoxia resulted in a 50% decline in placental GLUT-1 levels ( P < 0.05). In late-gestation ewes, maternal and fetal hyperglycemia caused an initial threefold increase at 48 h ( P< 0.05), with a persistent decline between 10 to 21 days, whereas maternal and fetal hypoglycemia led to a 30–50% decline in placental GLUT-1 levels ( P < 0.05). Studies in vitro demonstrated no effect of 0 mM, whereas 100 mM glucose caused a 60% decline ( P < 0.05; 48 h) in HRP.1 GLUT-1 levels compared with 5 mM of glucose. The added effect of hypoxia on 0 and 100 mM glucose concentrations appeared to increase GLUT-1 concentrations compared with normoxic cells ( P < 0.05; 100 mM at 18 h). We conclude that abnormal glucose concentrations alter rodent and ovine placental GLUT-1 levels in a time- and concentration-dependent manner; hypoxia may upregulate this effect. The changes in placental GLUT-1 concentrations may contribute toward the process of altered maternoplacentofetal transport of glucose, thereby regulating placental and fetal growth.


2001 ◽  
Vol 280 (1) ◽  
pp. G113-G120 ◽  
Author(s):  
Lan Jiang ◽  
Ronaldo P. Ferraris

Fructose transporter (GLUT-5) expression is low in mid-weaning rat small intestine, increases normally after weaning is completed, and can be precociously induced by premature consumption of a high-fructose (HF) diet. In this study, an in vivo perfusion model was used to determine the mechanisms regulating this substrate-induced reprogramming of GLUT-5 development. HF (100 mM) but not high-glucose (HG) perfusion increased GLUT-5 activity and mRNA abundance. In contrast, HF and HG perfusion had no effect on Na+-dependent glucose transporter (SGLT-1) expression but increased c- fos and c- jun expression. Intraperitoneal injection of actinomycin D before intestinal perfusion blocked the HF-induced increase in fructose uptake rate and GLUT-5 mRNA abundance. Actinomycin D also prevented the perfusion-induced increase in c- fos and c- jun mRNA abundance but did not affect glucose uptake rate and SGLT-1 mRNA abundance. Cycloheximide blocked the HF-induced increase in fructose uptake rate but not the increase in GLUT-5 mRNA abundance and had no effect on glucose uptake rate and SGLT-1 mRNA abundance. In neonatal rats, the substrate-induced reprogramming of intestinal fructose transport is likely to involve transcription and translation of the GLUT-5 gene.


1997 ◽  
Vol 272 (3) ◽  
pp. H1122-H1130 ◽  
Author(s):  
K. Hashimoto ◽  
T. Nishimura ◽  
M. Ishikawa ◽  
K. Koga ◽  
T. Mori ◽  
...  

This study quantifies the myocardial glucose uptake and clarifies the pathway of augmented glucose uptake in myocardium reperfused after a brief period of ischemia (stunned myocardium). The glucose uptake rate was determined from the time course of the sugar phosphate (SP) resonance in rat myocardium (d[SP]/dt) with 31P nuclear magnetic resonance after the substitution of glucose with its analog 2-deoxyglucose. The d[SP]/dt in stunned myocardium [1.03 +/- 0.05 (SE) micromol x g wet wt(-1) x min(-1); n = 8] increased significantly compared with nonischemic control myocardium (0.18 +/- 0.03 micromol x g wet wt(-1) x min(-1); n = 8; P < 0.0001), reaching the maximal stimulatory uptake rate during exposure to insulin (1.05 +/- 0.04 micromol x g wet wt(-1) x min(-1); n = 8). Twenty minutes after reperfusion, the d[SP]/dt was still augmented (0.41 +/- 0.05 micromol x g wet wt(-1) x min(-1); n = 5; P < 0.05 vs. control myocardium). To elucidate further the mechanism of augmented glucose uptake, N6-(L-2-phenylisopropyl)-adenosine (PIA; 100 micromol/l), a potent blocker of the glucose transporter, was administered to stunned hearts and, as a control, to insulin-stimulated hearts. PIA significantly and comparably inhibited the increase in d[SP]/dt in stunned myocardium (0.36 +/- 0.07 micromol x g wet wt(-1) x min(-1); n = 4; P < 0.0001 vs. without PIA) and in insulin-stimulated myocardium (0.38 +/- 0.02 micromol x g wet wt(-1) x min(-1); n = 4; P < 0.0001 vs. without PIA). These results indicate that the augmented glucose uptake in stunned myocardium is maintained by the glucose transporter, the amount of which is almost equal to that which can be maximally recruited by insulin.


2012 ◽  
Vol 24 (2) ◽  
pp. 344 ◽  
Author(s):  
M. Garcia-Herreros ◽  
I. M. Aparicio ◽  
D. Rath ◽  
T. Fair ◽  
P. Lonergan

Previous studies have shown that developmental kinetic rates following IVF are lower in female than in male blastocysts and that this may be related to differences in glucose metabolism. In addition, an inhibition of phosphatidylinositol 3-kinase (PI3-K) inhibits glucose uptake in murine blastocysts. Therefore, the aim of this study was to identify and compare the expression of proteins involved in glucose metabolism (hexokinase-I, HK-I; phosphofructokinase-1, PFK-1; pyruvate kinase1/2, PK1/2; glyceraldehyde-3-phosphate dehydrogenase, GAPDH; glucose transporter-1, GLUT-1; and glycogen synthase kinase-3, GSK-3) in male and female bovine blastocysts to determine whether PI3-K has a role in the regulation of the expression of these proteins. Hexokinase-I, PFK-1, PK1/2, GAPDH and GLUT-1 were present in bovine embryos. Protein expression of these proteins and GSK-3 was significantly higher in male compared with female blastocysts. Inhibition of PI3-K with LY294002 significantly decreased the expression of HK-I, PFK-1, GAPDH, GSK-3 A/B and GLUT-1. Results showed that the expression of glycolytic proteins HK-I, PFK-1, GAPDH and PK1/2, and the transporters GLUT-1 and GSK-3 is regulated by PI3-K in bovine blastocysts. Moreover, the differential protein expression observed between male and female blastocysts might explain the faster developmental kinetics seen in males, as the expression of main proteins involved in glycolysis and glycogenogenesis was significantly higher in male than female bovine embryos and also could explain the sensitivity of male embryos to a high concentration of glucose, as a positive correlation between GLUT-1 expression and glucose uptake in embryos has been demonstrated.


1996 ◽  
Vol 271 (2) ◽  
pp. C547-C554 ◽  
Author(s):  
W. S. Pascoe ◽  
K. Inukai ◽  
Y. Oka ◽  
J. W. Slot ◽  
D. E. James

We have examined the intracellular localization of five facilitative glucose transporter proteins, one endogenous (GLUT-1) and four exogenous (GLUT-2, -3, -4, and -5), in polarized epithelial cells. GLUT-2, -3, -4, and -5 were stably transfected into Madin-Darby canine kidney (MDCK) cells, and peptide-specific antibodies were used to establish their distribution by immunofluorescence and immunoelectron-microscopic techniques. GLUT-1 and -2 were predominantly targeted to the basolateral domain of the cell, whereas GLUT-3 and -5 were targeted to the apical plasma membrane. The insulin-regulatable glucose transporter GLUT-4 was found in intracellular tubulovesicular structures beneath the surface of the cell. Vectorial 2-deoxy-D-glucose uptake measurements revealed that approximately 95% of glucose entry into wild-type MDCK cells occurs via the basolateral membranes. In GLUT-3-transfected cells, however, apical glucose uptake increased to approximately 55%; this was not observed in cells expressing the other GLUT isoforms. The discrete and differential intracellular localizations of the various GLUTs, in addition to the high level of sequence homology and predicted secondary structure similarity, render the GLUT family ideal for the study of intrinsic targeting motifs involved in the establishment and maintenance of cellular polarity.


Endocrinology ◽  
2002 ◽  
Vol 143 (11) ◽  
pp. 4295-4303 ◽  
Author(s):  
M. Lucia Gavete ◽  
Maria Agote ◽  
M. Angeles Martin ◽  
Carmen Alvarez ◽  
Fernando Escriva

Abstract The high energy demands of myocardium are met through the metabolism of lipids and glucose. Importantly, enhanced glucose utilization rates are crucial adaptations of the cardiac cell to some pathological conditions, such as hypertrophy and ischemia, but the effects of undernutrition on heart glucose metabolism are unknown. Our previous studies have shown that undernutrition increases insulin-induced glucose uptake by skeletal muscle. Consequently, we considered the possibility of a similar adaptation in the heart. With this aim, undernourished rats both in the basal state and after euglycemic hyperinsulinemic clamps were used to determine the following parameters in myocardium: glucose uptake, glucose transporter (GLUT) content, and some key components of the insulin signaling cascade. Heart membranes were prepared by subcellular fractionation in sucrose gradients. Although GLUT-4, GLUT-1, and GLUT-3 proteins and GLUT-4/1 mRNAs were reduced by undernutrition, basal and insulin-stimulated 2-deoxyglucose uptake were significantly enhanced. Phosphoinositol 3-kinase activity remained greater than control values in both conditions. The abundance of p85α and p85β regulatory subunits of phosphoinositol 3-kinase was increased as was phospho-Akt during hyperinsulinemia. These changes seem to improve the insulin stimulus of GLUT-1 translocation, as its content was increased at the surface membrane. Such adaptations associated with undernutrition must be crucial to improvement of cardiac glucose uptake.


2001 ◽  
Vol 281 (5) ◽  
pp. R1545-R1552 ◽  
Author(s):  
Marianne S. Anderson ◽  
Judy Flowers-Ziegler ◽  
Utpala G. Das ◽  
William W. Hay ◽  
Sherin U. Devaskar

The acute effect of selective hyperglycemia or hyperinsulinemia on late gestation fetal ovine glucose transporter protein (GLUT-1, GLUT-3, and GLUT-4) concentrations was examined in insulin-insensitive (brain and liver) and insulin-sensitive (myocardium and fat) tissues at 1, 2.5, and 24 h. Hyperglycemia with euinsulinemia caused a two- to threefold increase in brain GLUT-3, liver GLUT-1, and myocardial GLUT-1 concentrations only at 1 h. There was no change in GLUT-4 protein amounts at any time during the selective hyperglycemia. In contrast, selective hyperinsulinemia with euglycemia led to an immediate and persistent twofold increase in liver GLUT-1, which lasted from 1 until 24 h with a concomitant decline in myocardial tissue GLUT-4 amounts, reaching statistical significance at 24 h. No other significant change in response to hyperinsulinemia was noted in any of the other isoforms in any of the other tissues. Simultaneous assessment of total fetal glucose utilization rate (GURf) during selective hyperglycemia demonstrated a transient 40% increase at 1 and 2.5 h, corresponding temporally with a transient increase in brain GLUT-3 and liver and myocardial GLUT-1 protein amounts. In contrast, selective hyperinsulinemia led to a sustained increase in GURf, corresponding temporally with the persistent increase in hepatic GLUT-1 concentrations. We conclude that excess substrate acutely increases GURf associated with an increase in various tissues of the transporter isoforms GLUT-1 and GLUT-3 that mediate fetal basal glucose transport without an effect on the GLUT-4 isoform that mediates insulin action. This contrasts with the tissue-specific effects of selective hyperinsulinemia with a sustained increase in GURfassociated with a sustained increase in hepatic basal glucose transporter (GLUT-1) amounts and a myocardial-specific emergence of mild insulin resistance associated with a downregulation of GLUT-4.


1995 ◽  
Vol 269 (3) ◽  
pp. R544-R551 ◽  
Author(s):  
X. Han ◽  
T. Ploug ◽  
H. Galbo

A diet rich in fat diminishes insulin-mediated glucose uptake in muscle. This study explored whether contraction-mediated glucose uptake is also affected. Rats were fed a diet rich in fat (FAT, 73% of energy) or carbohydrate (CHO, 66%) for 5 wk. Hindquarters were perfused, and either glucose uptake or glucose transport capacity (uptake of 3-O-[14C]-methyl-D-glucose (40 mM)) was measured. Amounts of glucose transporter isoform GLUT-1 and GLUT-4 glucose-transporting proteins were determined by Western blot. Glucose uptake was lower (P < 0.05) in hindlegs from FAT than from CHO rats at submaximum and maximum insulin [4 +/- 0.4 vs. 5 +/- 0.3 (SE) mumol.min-1.leg-1 at 150 microU/ml insulin] as well as during prolonged stimulation of the sciatic nerve (4.4 +/- 0.4 vs. 5.6 +/- 0.6 mumol.min-1.leg-1). Maximum glucose transport elicited by insulin (soleus: 1.7 +/- 0.2 vs. 2.6 +/- 0.2 mumol.g-1.5 min-1, P < 0.05) or contractions (soleus: 1.8 +/- 0.2 vs. 2.6 +/- 0.3, P < 0.05) in red muscle was decreased in parallel in FAT compared with CHO rats. GLUT-4 content was decreased by 13-29% (P < 0.05) in the various fiber types, whereas GLUT-1 content was identical in FAT compared with CHO rats. It is concluded that a FAT diet reduces both insulin and contraction stimulation of glucose uptake in muscle and that these effects are associated with diminished skeletal muscle glucose transport capacities and GLUT-4 contents.


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