scholarly journals Differential regulation of the HepG2 and adipocyte/muscle glucose transporters in 3T3L1 adipocytes. Effect of chronic glucose deprivation

1990 ◽  
Vol 271 (1) ◽  
pp. 201-207 ◽  
Author(s):  
K M Tordjman ◽  
K A Leingang ◽  
M Mueckler
Keyword(s):  
Glucose Transport ◽  
Glucose Transporter ◽  
Glucose Deprivation ◽  
Transport Systems ◽  
Facilitated Diffusion ◽  
Glucose Starvation ◽  
Transport Activity ◽  
Maximal Increase ◽  
Glut 1 ◽  
Glut 4

Glucose transport in 3T3L1 adipocytes is mediated by two facilitated diffusion transport systems. We examined the effect of chronic glucose deprivation on transport activity and on the expression of the HepG2 (GLUT 1) and adipocyte/muscle (GLUT 4) glucose transporter gene products in this insulin-sensitive cell line. Glucose deprivation resulted in a maximal increase in 2-deoxyglucose uptake of 3.6-fold by 24 h. Transport activity declined thereafter but was still 2.4-fold greater than the control by 72 h. GLUT 1 mRNA and protein increased progressively during starvation to values respectively 2.4- and 7.0-fold greater than the control by 72 h. Much of the increase in total immunoreactive GLUT 1 protein observed later in starvation was the result of the accumulation of a non-functional or mistargeted 38 kDa polypeptide. Immunofluorescence microscopy indicated that increases in GLUT 1 protein occurred in presumptive plasma membrane (PM) and Golgi-like compartments during prolonged starvation. The steady-state level of GLUT 4 protein did not change during 72 h of glucose deprivation despite a greater than 10-fold decrease in the mRNA. Subcellular fractionation experiments indicated that the increased transport activity observed after 24 h of starvation was principally the result of an increase in the 45-50 kDa GLUT 1 transporter protein in the PM. The level of the GLUT 1 transporter in the PM and low-density microsomes (LDM) was increased by 3.9- and 1.4-fold respectively, and the GLUT 4 transporter content of the PM and LDM was 1.7- and 0.6-fold respectively greater than that of the control after 24 h of glucose deprivation. These data indicate that newly synthesized GLUT 1 transporters are selectively shuttled to the PM and that GLUT 4 transporters undergo translocation from an intracellular compartment to the PM during 24 h of glucose starvation. Thus glucose starvation results in an increase in glucose transport in 3T3L1 adipocytes via a complex series of events involving increased biosynthesis, decreased turnover and subcellular redistribution of transporter proteins.

Effects of fish and safflower oil feeding on subcellular glucose transporter distributions in rat adipocytes

1992 ◽  
Vol 263 (1) ◽  
pp. E94-E101 ◽  
Author(s):  
O. Ezaki ◽  
E. Tsuji ◽  
K. Momomura ◽  
M. Kasuga ◽  
H. Itakura
Keyword(s):  
Fish Oil ◽  
Cell Size ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Size Increase ◽  
Safflower Oil ◽  
Transport Activity ◽  
Glut 1 ◽  
Rat Adipocytes ◽  
Glut 4

Effects of fish oil feeding on glucose transport systems and cell size in rat adipocytes were examined and compared with those of safflower oil or carbohydrate feeding under isoenergy intake conditions. Glucose transport activity was assessed by measuring 3-O-methyl-D-glucose transport. The concentration of erythrocyte type glucose transporter (GLUT-1) and muscle/fat type transporter (GLUT-4) was measured by immunoblotting. The amount of each transporter in intact cells was estimated by the amount of transporter and protein of each membrane fraction and by the recovery of marker enzymes. In cells from safflower-fed rats compared with those from carbohydrate-fed rats, insulin-stimulated glucose transport activity per cell decreased to 51% after a 1-wk feeding, and cell size increase became larger with these effects and continued for at least 4 wk. At 1 wk of feeding, GLUT-1 and GLUT-4 per cell in plasma membrane from insulin-treated cells decreased to 62 and 35%, respectively, with concomitant transporter decreases in the low-density microsome fraction. In cells from high-fish oil-fed rats in which two-thirds of safflower oil was replaced by fish oil, when compared with those from safflower oil-fed rats, insulin-stimulated glucose transport activity increased 1.7-fold after 1 wk of feeding with concomitant cellular GLUT-1 and GLUT-4 increases, but its effect declined thereafter. Parallel with this time course, cell size increase was smaller after 1 wk, but this effect also declined thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Differential regulation of the GLUT-1 and GLUT-4 glucose transport systems by glucose and insulin in L6 muscle cells in culture

1991 ◽  
Vol 266 (4) ◽  
pp. 2615-2621 ◽  
Author(s):  
U M Koivisto ◽  
H Martinez-Valdez ◽  
P J Bilan ◽  
E Burdett ◽  
T Ramlal ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Muscle Cells ◽  
Differential Regulation ◽  
Transport Systems ◽  
Glut 1 ◽  
Glut 4 ◽  
Cells In Culture ◽  
L6 Muscle Cells

Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

1990 ◽  
Vol 259 (6) ◽  
pp. E778-E786 ◽  
Author(s):  
T. Ploug ◽  
B. M. Stallknecht ◽  
O. Pedersen ◽  
B. B. Kahn ◽  
T. Ohkuwa ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Training Session ◽  
Residual Effect ◽  
Exercise Session ◽  
Transport Capacity ◽  
Glut 1 ◽  
Glut 4 ◽  
Fast Twitch

The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.

Glucose transporters and glucose transport in skeletal muscles of 1- to 25-mo-old rats

1993 ◽  
Vol 264 (3) ◽  
pp. E319-E327 ◽  
Author(s):  
E. A. Gulve ◽  
E. J. Henriksen ◽  
K. J. Rodnick ◽  
J. H. Youn ◽  
J. O. Holloszy
Keyword(s):  
Glucose Transport ◽  
Skeletal Muscles ◽  
Glucose Transporter ◽  
Contractile Activity ◽  
Transport Activity ◽  
Glut 4 ◽  
Flexor Digitorum Brevis ◽  
Old Rats ◽  
Growth And Aging ◽  
Flexor Digitorum

It is widely thought that aging results in development of insulin resistance in skeletal muscle. In this study, we examined the effects of growth and aging on the concentration of the GLUT-4 glucose transporter and on glucose transport activity in skeletal muscles of female Long-Evans rats. Relative amounts of immunoreactive GLUT-4 protein were measured in muscle homogenates of 1-, 10-, and 25-mo-old rats by immunoblotting with a polyclonal antibody directed against GLUT-4. In the epitrochlearis, plantaris, and the red and white regions of the quadriceps muscles, GLUT-4 immunoreactivity decreased by 14-33% between 1 and 10 mo of age and thereafter remained constant. In flexor digitorum brevis (FDB) and soleus muscles, GLUT-4 concentration was similar at all three ages studied. Glucose transport activity was assessed in epitrochlearis and FDB muscles by incubation with 2-deoxyglucose under the following conditions: basal, submaximal insulin, and either maximal insulin or maximal insulin combined with contractile activity. Glucose transport in the epitrochlearis muscle decreased by approximately 60% between 1 and 4 mo of age and then did not decline further between 4 and 25 mo of age. Transport activity in the FDB assessed with a maximally effective insulin concentration decreased only slightly (< 20%) between 1 and 7 mo of age. Aging, i.e., the transition from young adulthood to old age, was not associated with a decrease in glucose transport activity in either the epitrochlearis or the FDB.(ABSTRACT TRUNCATED AT 250 WORDS)

Glucose transporter protein content and glucose transport capacity in rat skeletal muscles

1990 ◽  
Vol 259 (4) ◽  
pp. E593-E598 ◽  
Author(s):  
E. J. Henriksen ◽  
R. E. Bourey ◽  
K. J. Rodnick ◽  
L. Koranyi ◽  
M. A. Permutt ◽  
...  
Keyword(s):  
Protein Content ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Contractile Activity ◽  
Fiber Type ◽  
Linear Regression Analysis ◽  
Type I ◽  
Fiber Types ◽  
Transport Activity ◽  
Glut 4

The relationships among fiber type, glucose transporter (GLUT-4) protein content, and glucose transport activity stimulated maximally with insulin and/or contractile activity were studied by use of the rat epitrochlearis (15% type I-20% type II2a-65% type IIb), soleus (84-16-0%), extensor digitorum longus (EDL, 3-57-40%), and flexor digitorum brevis (FDB, 7-92-1%) muscles. Insulin-stimulated 2-deoxy-D-glucose (2-DG) uptake was greatest in the soleus, followed (in order) by the FDB, EDL, and epitrochlearis. On the other hand, contractile activity induced the greatest increase in 2-DG uptake in the FDB, followed by the EDL, soleus, and epitrochlearis. The effects of insulin and contractile activity on 2-DG uptake were additive in all the muscle preparations, with the relative rates being FDB greater than soleus greater than EDL greater than epitrochlearis. Quantitation of the GLUT-4 protein content with the antiserum R820 showed the following pattern: FDB greater than soleus greater than EDL greater than epitrochlearis. Linear regression analysis showed that whereas a relatively low and nonsignificant correlation existed between GLUT-4 protein content and 2-DG uptake stimulated by insulin alone, significant correlations existed between GLUT-4 protein content and 2-DG uptake stimulated either by contractions alone (r = 0.950) or by insulin and contractions in combination (r = 0.992). These results suggest that the differences in maximally stimulated glucose transport activity among the three fiber types may be related to differences in their content of GLUT-4 protein.

Effect of diet on insulin- and contraction-mediated glucose transport and uptake in rat muscle

1995 ◽  
Vol 269 (3) ◽  
pp. R544-R551 ◽  
Author(s):  
X. Han ◽  
T. Ploug ◽  
H. Galbo
Keyword(s):  
Glucose Uptake ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Fiber Types ◽  
Transport Capacity ◽  
Glut 1 ◽  
Glut 4 ◽  
Red Muscle ◽  
Muscle Glucose Transport ◽  
Stimulation Of

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.

scholarly journals The efficient intracellular sequestration of the insulin-regulatable glucose transporter (GLUT-4) is conferred by the NH2 terminus

1992 ◽  
Vol 117 (4) ◽  
pp. 729-743 ◽  
Author(s):  
RC Piper ◽  
C Tai ◽  
JW Slot ◽  
CS Hahn ◽  
CM Rice ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Glucose Transport ◽  
Cho Cells ◽  
Sindbis Virus ◽  
Glucose Transporter ◽  
Intracellular Compartment ◽  
Glut 1 ◽  
Glut 4 ◽  
Intracellular Sequestration

GLUT-4 is the major facilitative glucose transporter isoform in tissues that exhibit insulin-stimulated glucose transport. Insulin regulates glucose transport by the rapid translocation of GLUT-4 from an intracellular compartment to the plasma membrane. A critical feature of this process is the efficient exclusion of GLUT-4 from the plasma membrane in the absence of insulin. To identify the amino acid domains of GLUT-4 which confer intracellular sequestration, we analyzed the subcellular distribution of chimeric glucose transporters comprised of GLUT-4 and a homologous isoform, GLUT-1, which is found predominantly at the cell surface. These chimeric transporters were transiently expressed in CHO cells using a double subgenomic recombinant Sindbis virus vector. We have found that wild-type GLUT-4 is targeted to an intracellular compartment in CHO cells which is morphologically similar to that observed in adipocytes and muscle cells. Sindbis virus-produced GLUT-1 was predominantly expressed at the cell surface. Substitution of the GLUT-4 amino-terminal region with that of GLUT-1 abolished the efficient intracellular sequestration of GLUT-4. Conversely, substitution of the NH2 terminus of GLUT-1 with that of GLUT-4 resulted in marked intracellular sequestration of GLUT-1. These data indicate that the NH2-terminus of GLUT-4 is both necessary and sufficient for intracellular sequestration.

scholarly journals Translocation of the brain-type glucose transporter largely accounts for insulin stimulation of glucose transport in BC3H-1 myocytes

1990 ◽  
Vol 269 (3) ◽  
pp. 597-601 ◽  
Author(s):  
D M Calderhead ◽  
K Kitagawa ◽  
G E Lienhard ◽  
G W Gould
Keyword(s):  
Glucose Transport ◽  
Glucose Transporter ◽  
Fold Increase ◽  
The Other ◽  
Insulin Stimulation ◽  
Glut 1 ◽  
Glut 4 ◽  
Rat Soleus Muscle ◽  
The Brain ◽  
Stimulation Of

Insulin-stimulated glucose transport was examined in BC3H-1 myocytes. Insulin treatment lead to a 2.7 +/- 0.3-fold increase in the rate of deoxyglucose transport and, under the same conditions, a 2.1 +/- 0.1-fold increase in the amount of the brain-type glucose transporter (GLUT 1) at the cell surface. It has been shown that some insulin-responsive tissues express a second, immunologically distinct, transporter, namely GLUT 4. We report here that BC3H-1 myocytes and C2 and G8 myotubes express only GLUT 1; in contrast, rat soleus muscle and heart express 3-4 times higher levels of GLUT 4 than GLUT 1. Thus translocation of GLUT 1 can account for most, if not all, of the insulin stimulation of glucose transport in BC3H-1 myocytes. On the other, hand, neither BC3H-1 myocytes nor the other muscle-cell lines are adequate as models for the study of insulin regulation of glucose transport in muscle tissue.

Adaptation of muscle to creatine depletion: effect on GLUT-4 glucose transporter expression

1993 ◽  
Vol 264 (1) ◽  
pp. C146-C150 ◽  
Author(s):  
J. M. Ren ◽  
C. F. Semenkovich ◽  
J. O. Holloszy
Keyword(s):  
Glucose Transport ◽  
Protein Concentration ◽  
Glucose Transporter ◽  
Citrate Synthase ◽  
Oxidative Enzymes ◽  
Mitochondrial Enzymes ◽  
Striated Muscles ◽  
Transport Activity ◽  
Glut 4 ◽  
Depletion Effect

Feeding rats beta-guanidinopropionic acid (beta-GPA), a creatine analogue, results in depletion of creatine and phosphocreatine and induces increases in mitochondrial oxidative enzymes and hexokinase in skeletal muscle. Comparisons of different muscle types and studies of the adaptation to exercise suggest that 1) the levels of the insulin-responsive glucose transporter (GLUT-4), mitochondrial oxidative enzymes, and hexokinase may be coregulated and 2) GLUT-4 content can determine maximal glucose transport activity in muscle. To further evaluate these possibilities, we examined the effects of feeding rats 1% beta-GPA in their diet for 6 wk on muscle GLUT-4 expression and glucose transport activity. beta-GPA feeding induced 40-50% increases in cytochrome c concentration, citrate synthase activity, and hexokinase activity in plantaris muscle. GLUT-4 protein concentration was increased approximately 50% in plantaris and epitrochlearis muscles, while GLUT-4 mRNA was increased approximately 40% in plantaris muscles of beta-GPA-fed rats. Glucose transport activity maximally stimulated by insulin was increased in parallel with GLUT-4 protein concentration in the epitrochlearis. These results provide evidence that chronic creatine depletion increases GLUT-4 expression by pretranslational mechanisms. They support the hypothesis that the levels of mitochondrial enzymes, hexokinase, and GLUT-4 protein are coregulated in striated muscles. They also support the concept that the GLUT-4 content of a muscle determines its maximal glucose transport activity when the signaling pathways for glucose transport activation are intact.

Effect of physical training on glucose transporter protein and mRNA levels in rat adipocytes

1993 ◽  
Vol 265 (1) ◽  
pp. E128-E134 ◽  
Author(s):  
B. Stallknecht ◽  
P. H. Andersen ◽  
J. Vinten ◽  
L. L. Bendtsen ◽  
J. Sibbersen ◽  
...  
Keyword(s):  
Glucose Transport ◽  
Physical Training ◽  
Glucose Transporter ◽  
Glucose Transporters ◽  
Intrinsic Activity ◽  
Mrna Levels ◽  
Glut 1 ◽  
Transporter Protein ◽  
Glut 4 ◽  
Adipocyte Volume

Physical training increases insulin-stimulated glucose transport and the number of glucose transporters in adipocytes measured by cytochalasin B binding. In the present study we used immunoblotting to measure the abundance of two glucose transporters (GLUT-4, GLUT-1) in white adipocytes from trained rats. Furthermore, the abundance of the mRNAs for these proteins and glucose transport was measured. Rats were swim-trained for 10 wk, and adipocytes were isolated from epididymal fat pads. The amount of GLUT-4/adipocyte volume unit was significantly higher in trained animals compared with both age- and cell size-matched animals. The amount of GLUT-4 mRNA was also increased by training and it decreased with increasing age. Furthermore, young age as well as training was accompanied by relatively low GLUT-4 protein/mRNA and relatively high overall GLUT-4 efficiency (recruitability and/or intrinsic activity). GLUT-1 protein and mRNA levels/adipocyte volume did not change with age or training.

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