O-22: Regulation of glucose transport in skeletal muscle of rats and mice is mediated by the cell surface concentration of GLUT4

Skeletal muscle glucose transport was examined in transgenic mice overexpressing the glucose transporter GLUT1 using both the isolated incubated-muscle preparation and the hind-limb perfusion technique. In the absence of insulin, 2-deoxy-d-glucose uptake was increased ∼ 3–8-fold in isolated fast-twitch muscles of GLUT1 transgenic mice compared with non-transgenic siblings. Similarly, basal glucose transport activity was increased ∼ 4–14-fold in perfused fast-twitch muscles of transgenic mice. In non-transgenic mice insulin accelerated glucose transport activity ∼ 2–3-fold in isolated muscles and to a much greater extent (∼ 7–20-fold) in perfused hind-limb preparations. The observed effect of insulin on glucose transport in transgenic muscle was similarly dependent upon the technique used for measurement, as insulin had no effect on isolated fast-twitch muscle from transgenic mice, but significantly enhanced glucose transport in perfused fast-twitch muscle from transgenic mice to ∼ 50–75% of the magnitude of the increase observed in non-transgenic mice. Cell-surface glucose transporter content was assessed via 2-N-4-(l-azi-2,2,2-trifluoroethyl)benzoyl-1,3-bis-(d -mannos-4-yloxy)-2-propylamine photolabelling methodology in both isolated and perfused extensor digitorum longus (EDL). Cell-surface GLUT1 was enhanced by as much as 70-fold in both isolated and perfused EDL of transgenic mice. Insulin did not alter cell-surface GLUT1 in either transgenic or non-transgenic mice. Basal levels of cell-surface GLUT4, measured in either isolated or perfused EDL, were similar in transgenic and non-transgenic mice. Interestingly, insulin enhanced cell-surface GLUT4 ∼ 2-fold in isolated EDL and ∼ 6-fold in perfused EDL of both transgenic and non-transgenic mice. In summary, these results reveal differences between isolated muscle and perfused hind-limb techniques, with the latter method showing a more robust responsiveness to insulin. Furthermore, the results demonstrate that muscle overexpressing GLUT1 has normal insulin-induced GLUT4 translocation and the ability to augment glucose-transport activity above the elevated basal rates.

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Insulin stimulation of glucose transport activity in rat skeletal muscle: increase in cell surface GLUT4 as assessed by photolabelling

Biochemical Journal ◽

10.1042/bj2990755 ◽

1994 ◽

Vol 299 (3) ◽

pp. 755-759 ◽

Cited By ~ 56

Author(s):

C M Wilson ◽

S W Cushman

Keyword(s):

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Fold Increase ◽

Transport Activity ◽

Insulin Stimulation ◽

Rat Skeletal Muscle ◽

Photoaffinity Label ◽

Isolated Rat ◽

Stimulation Of

We have used a photoaffinity label to quantify cell surface GLUT4 glucose transporters in isolated rat soleus muscles. In this system, insulin stimulated an 8.6-fold increase in 3-O-methylglucose glucose transport, while photolabelled GLUT4 increased 8-fold. These results demonstrate that the insulin-stimulated increase in glucose transport activity in skeletal muscle can be accounted for by an increase in surface-accessible GLUT4 content.

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Regulation of cell surface GLUT4 in skeletal muscle of transgenic mice

Biochemical Journal ◽

10.1042/bj3210075 ◽

1997 ◽

Vol 321 (1) ◽

pp. 75-81 ◽

Cited By ~ 17

Author(s):

Joseph T. BROZINICK ◽

Scott C. McCOID ◽

Thomas H. REYNOLDS ◽

Cindy M. WILSON ◽

Ralph W. STEVENSON ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Glucose Transporter ◽

Subcellular Fractionation ◽

Muscle Membrane ◽

Transport Activity ◽

Hindlimb Muscles ◽

Subcellular Membrane ◽

Glucose Transporter Glut4

Marked overexpression of the glucose transporter GLUT4 in skeletal muscle membrane fractions of GLUT4 transgenic (TG) mice is accompanied by disproportionately small increases in basal and insulin-stimulated glucose transport activity. Thus we have assessed cell surface GLUT4 by photolabelling with the membrane-impermeant reagent 2-N-[4-(1-azi-2,2,2-trifluoroethyl)benzoyl]-1,3-bis(d-mannos-4-yloxy)-2-propylamine (ATB-BMPA) and measured the corresponding glucose transport activity using 2-deoxyglucose in isolated extensor digitorum longus (EDL) muscles from non-transgenic (NTG) and GLUT4 TG mice in the absence and presence of 13.3 nM (2000 µ-units/ml) insulin, without or with hypoxia as a model of muscle contraction. TG mice displayed elevated rates of glucose transport activity under basal and insulin-stimulated conditions, and in the presence of insulin plus hypoxia, compared with NTG mice. Photoaffinity labelling of cell surface GLUT4 indicated corresponding elevations in plasma membrane GLUT4 in the basal and insulin-stimulated states, and with insulin plus hypoxia, but no difference in cell surface GLUT4 during hypoxia stimulation. Subcellular fractionation of hindlimb muscles confirmed the previously observed 3-fold overexpression of GLUT4 in the TG compared with the NTG mice. These results suggest that: (1) alterations in glucose transport activity which occur with GLUT4 overexpression in EDL muscles are directly related to cell surface GLUT4 content, regardless of the levels observed in the corresponding subcellular membrane fractions, (2) while overexpression of GLUT4 influences both basal and insulin-stimulated glucose transport activity, the response to hypoxia/contraction-stimulated glucose transport is unchanged, and (3) subcellular fractionation provides little insight into the subcellular trafficking of GLUT4, and whatever relationship is demonstrated in EDL muscles from NTG mice is disrupted on GLUT4 overexpression.

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Glucose transport and cell surface GLUT-4 protein in skeletal muscle of the obese Zucker rat

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1996.271.2.e294 ◽

1996 ◽

Vol 271 (2) ◽

pp. E294-E301 ◽

Cited By ~ 37

Author(s):

G. J. Etgen ◽

C. M. Wilson ◽

J. Jensen ◽

S. W. Cushman ◽

J. L. Ivy

Keyword(s):

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Zucker Rats ◽

Zucker Rat ◽

Glut 4 ◽

Obese Zucker Rat ◽

Obese Rats ◽

Slow Twitch ◽

Fast Twitch

The relationship between 3-O-methyl-D-glucose transport and 2-N-4-(1-azi-2,2,2-trifluoroethyl)-benzoyl-1, 3-bis-(D-mannos-4-yloxy)-2-propylamine (ATB-BMPA)-labeled cell surface GLUT-4 protein was assessed in fast-twitch (epitrochlearis) and slow-twitch (soleus) muscles of lean and obese (fa/fa) Zucker rats. In the absence of insulin, glucose transport as well as cell surface GLUT-4 protein was similar in both epitrochlearis and soleus muscles of lean and obese rats. In contrast, insulin-stimulated glucose transport rates were significantly higher for lean than obese rats in both soleus (0.74 +/- 0.05 vs. 0.40 +/- 0.02 mumol.g-1.10 min-1) and epitrochlearis (0.51 +/- 0.05 vs. 0.17 +/- 0.02 mumol.g-1.10 min-1) muscles. The ability of insulin to enhance glucose transport in fast- and slow-twitch muscles from both lean and obese rats corresponded directly with changes in cell surface GLUT-4 protein. Muscle contraction elicited similar increases in glucose transport in lean and obese rats, with the effect being more pronounced in fast-twitch (0.70 +/- 0.07 and 0.77 +/- 0.04 mumol.g-1.10 min-1 for obese and lean, respectively) than in slow-twitch muscle (0.36 +/- 0.03 and 0.40 +/- 0.02 mumol.g-1.10 min-1 for obese and lean, respectively). The contraction-induced changes in glucose transport directly corresponded with the observed changes in cell surface GLUT-4 protein. Thus the reduced glucose transport response to insulin in skeletal muscle of the obese Zucker rat appears to result directly from an inability to effectively enhance cell surface GLUT-4 protein.

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Abnormal glucose transport and GLUT1 cell-surface content in fibroblasts and skeletal muscle from NIDDM and obese subjects

Diabetologia ◽

10.1007/s001250050696 ◽

1997 ◽

Vol 40 (4) ◽

pp. 421-429 ◽

Cited By ~ 25

Author(s):

C. Miele ◽

P. Formisano ◽

G. Condorelli ◽

M. Caruso ◽

F. Oriente ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Obese Subjects ◽

Surface Content

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5-Amino-Imidazole Carboxamide Riboside Increases Glucose Transport and Cell-Surface GLUT4 Content in Skeletal Muscle From Subjects With Type 2 Diabetes

Diabetes ◽

10.2337/diabetes.52.5.1066 ◽

2003 ◽

Vol 52 (5) ◽

pp. 1066-1072 ◽

Cited By ~ 170

Author(s):

H. A. Koistinen ◽

D. Galuska ◽

A. V. Chibalin ◽

J. Yang ◽

J. R. Zierath ◽

...

Keyword(s):

Type 2 Diabetes ◽

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Amino Imidazole

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Calorie restriction increases cell surface GLUT-4 in insulin-stimulated skeletal muscle

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1998.275.6.e957 ◽

1998 ◽

Vol 275 (6) ◽

pp. E957-E964 ◽

Cited By ~ 17

Author(s):

David J. Dean ◽

Joseph T. Brozinick ◽

Samuel W. Cushman ◽

Gregory D. Cartee

Keyword(s):

Skeletal Muscle ◽

Cell Surface ◽

Glucose Transport ◽

Calorie Restriction ◽

Glucose Transporter ◽

Calorie Intake ◽

Phosphatidylinositol 3 Kinase ◽

Glut 4 ◽

Pi3k Activity ◽

Stimulation Of

Reduced calorie intake [calorie restriction (CR); 60% of ad libitum (AL)] leads to enhanced glucose transport without altering total GLUT-4 glucose transporter abundance in skeletal muscle. Therefore, we tested the hypothesis that CR (20 days) alters the subcellular distribution of GLUT-4. Cell surface GLUT-4 content was higher in insulin-stimulated epitrochlearis muscles from CR vs. AL rats. The magnitude of this increase was similar to the CR-induced increase in glucose transport, and GLUT-4 activity (glucose transport rate divided by cell surface GLUT-4) was unaffected by diet. The CR effect was specific to the insulin-mediated pathway, as evidenced by the observations that basal glucose transport and cell surface GLUT-4 content, as well as hypoxia-stimulated glucose transport, were unchanged by diet. CR did not alter insulin’s stimulation of insulin receptor substrate (IRS)-1-associated phosphatidylinositol 3-kinase (PI3K) activity. Muscle abundance of IRS-2 and p85 subunit of PI3K were unaltered by diet, but IRS-1 content was lower in CR vs. AL. These data demonstrate that, despite IRS-1-PI3K activity similar to AL, CR specifically increases insulin’s activation of glucose transport by enhancing the steady-state proportion of GLUT-4 residing on the cell surface.

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