Insulin action on glucose transport and plasma membrane GLUT4 content in skeletal muscle from patients with NIDDM

Skeletal muscle regeneration is mediated by the proliferation of myoblasts from stem cells located beneath the basal lamina of myofibres, the muscle satellite cells. They are functionally indistinguishable from embryonic myoblasts. The myogenic process includes the fusion of myoblasts into multinucleated myotubes, the biosynthesis of proteins specific for skeletal muscle and proteins that regulates glucose metabolism, the glucose transporters. We find that three isoforms of glucose transporter are expressed during foetal myoblast differentiation: GLUT1, GLUT3 and GLUT4; their relative expression being dependent upon the stage of differentiation of the cells. GLUT1 mRNA and protein were abundant only in myoblasts from 19-day-old rat foetuses or from adult muscles. GLUT3 mRNA and protein, detectable in both cell types, increased markedly during cell fusion, but decreased in contracting myotubes. GLUT4 mRNA and protein were not expressed in myoblasts. They appeared only in spontaneously contracting myotubes cultured on an extracellular matrix. Insulin or IGF-I had no effect on the expression of the three glucose transporter isoforms, even in the absence of glucose. The rate of glucose transport, assessed using 2-[3H]deoxyglucose, was 2-fold higher in myotubes than in myoblasts. Glucose deprivation increased the basal rate of glucose transport by 2-fold in myoblasts, and 4-fold in myotubes. The cellular localization of the glucose transporters was directly examined by immunofluorescence staining. GLUT1 was located on the plasma membrane of myoblasts and myotubes. GLUT3 was located intracellularly in myoblasts and appeared also on the plasma membrane in myotubes. Insulin or IGF-I were unable to target GLUT3 to the plasma membrane. GLUT4, the insulin-regulatable glucose transporter isoform, appeared only in contracting myotubes in small intracellular vesicles. It was translocated to the plasma membrane after a short exposure to insulin, as it is in skeletal muscle in vivo. These results show that there is a switch in glucose transporter isoform expression during myogenic differentiation, dependent upon the energy required by the different stages of the process. GLUT3 seemed to play a role during cell fusion, and could be a marker for the muscle's ability to regenerate.

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Kinetics of glucose transport in rat skeletal muscle membrane vesicles: effects of insulin and contractions

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1992.262.5.e700 ◽

1992 ◽

Vol 262 (5) ◽

pp. E700-E711 ◽

Cited By ~ 11

Author(s):

T. Ploug ◽

H. Galbo ◽

T. Ohkuwa ◽

J. Tranum-Jensen ◽

J. Vinten

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Glucose Transport ◽

Cytochalasin B ◽

Equilibrium Distribution ◽

Initial Rate ◽

Membrane Vesicles ◽

Membrane Preparation ◽

Muscle Membrane ◽

Distribution Space

To study the mechanism of acceleration of glucose transport in skeletal muscle after stimulation with insulin and contractions, we isolated a subcellular vesicular membrane fraction, highly enriched in the plasma membrane enzyme K(+)-stimulated p-nitrophenylphosphatase and also enriched in some intracellular membranes. Protein recovery, morphology, lipid content, marker enzyme activities, total intravesicular volume, Western blot quantitation of GLUT-1, and glucose-inhibitable cytochalasin B binding were identical in membrane fractions from control, insulin-stimulated, contraction-stimulated, and insulin- and contraction-stimulated muscle. Time course of D-[3H]glucose entry in membrane vesicles at equilibrium exchange conditions showed that initial rate of transport at 30 mM of glucose was increased 19-fold and that equilibrium distribution space was increased 4-fold in vesicles from maximum stimulated muscle. The effects of insulin and contractions on initial rate of transport as well as on equilibrium distribution space were additive, and stimulation increased the substrate saturability of glucose transport. Furthermore, cytochalasin B binding to membranes prepared by using less centrifugation time than usual showed that, after stimulation with insulin and contractions, at least 35% of the total number of glucose transporters were redistributed from one kind of vesicles to a more slowly sedimenting kind of vesicles, probably reflecting translocation within the membrane preparation from intracellular vesicles to the plasma membrane upon stimulation. In the present membrane preparation the effects of insulin and/or contractions on glucose transport resemble those seen in intact muscle, and the effects are thus not dependent on cellular integrity.(ABSTRACT TRUNCATED AT 250 WORDS)

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Acute selective glycogen synthase kinase-3 inhibition enhances insulin signaling in prediabetic insulin-resistant rat skeletal muscle

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00547.2004 ◽

2005 ◽

Vol 288 (6) ◽

pp. E1188-E1194 ◽

Cited By ~ 63

Author(s):

Betsy B. Dokken ◽

Julie A. Sloniger ◽

Erik J. Henriksen

Keyword(s):

Skeletal Muscle ◽

Tyrosine Phosphorylation ◽

Glucose Transport ◽

Insulin Signaling ◽

Insulin Action ◽

Glycogen Synthase ◽

Serine Phosphorylation ◽

Zucker Rats ◽

Type I ◽

Insulin Resistant

Glycogen synthase kinase-3 (GSK3) has been implicated in the multifactorial etiology of skeletal muscle insulin resistance in animal models and in human type 2 diabetic subjects. However, the potential molecular mechanisms involved are not yet fully understood. Therefore, we determined if selective GSK3 inhibition in vitro leads to an improvement in insulin action on glucose transport activity in isolated skeletal muscle of insulin-resistant, prediabetic obese Zucker rats and if these effects of GSK3 inhibition are associated with enhanced insulin signaling. Type I soleus and type IIb epitrochlearis muscles from female obese Zucker rats were incubated in the absence or presence of a selective, small organic GSK3 inhibitor (1 μM CT118637, Ki < 10 nM for GSK3α and GSK3β). Maximal insulin stimulation (5 mU/ml) of glucose transport activity, glycogen synthase activity, and selected insulin-signaling factors [tyrosine phosphorylation of insulin receptor (IR) and IRS-1, IRS-1 associated with p85 subunit of phosphatidylinositol 3-kinase, and serine phosphorylation of Akt and GSK3] were assessed. GSK3 inhibition enhanced ( P <0.05) basal glycogen synthase activity and insulin-stimulated glucose transport in obese epitrochlearis (81 and 24%) and soleus (108 and 20%) muscles. GSK3 inhibition did not modify insulin-stimulated tyrosine phosphorylation of IR β-subunit in either muscle type. However, in obese soleus, GSK3 inhibition enhanced (all P < 0.05) insulin-stimulated IRS-1 tyrosine phosphorylation (45%), IRS-1-associated p85 (72%), Akt1/2 serine phosphorylation (30%), and GSK3β serine phosphorylation (39%). Substantially smaller GSK3 inhibitor-mediated enhancements of insulin action on these insulin signaling factors were observed in obese epitrochlearis. These results indicate that selective GSK3 inhibition enhances insulin action in insulin-resistant skeletal muscle of the prediabetic obese Zucker rat, at least in part by relieving the deleterious effects of GSK3 action on post-IR insulin signaling. These effects of GSK3 inhibition on insulin action are greater in type I muscle than in type IIb muscle from these insulin-resistant animals.

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Stimulation of glucose transport in skeletal muscle by hypoxia

Journal of Applied Physiology ◽

10.1152/jappl.1991.70.4.1593 ◽

1991 ◽

Vol 70 (4) ◽

pp. 1593-1600 ◽

Cited By ~ 203

Author(s):

G. D. Cartee ◽

A. G. Douen ◽

T. Ramlal ◽

A. Klip ◽

J. O. Holloszy

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Muscle Contraction ◽

Glucose Transport ◽

Glucose Transporter ◽

Cytochalasin B ◽

Sugar Transport ◽

Transport Activity ◽

Hindlimb Muscles ◽

Stimulation Of

Hypoxia caused a progressive cytochalasin B-inhibitable increase in the rate of 3-O-methylglucose transport in rat epitrochlearis muscles to a level approximately six-fold above basal. Muscle ATP concentration was well maintained during hypoxia, and increased glucose transport activity was still present after 15 min of reoxygenation despite repletion of phosphocreatine. However, the increase in glucose transport activity completely reversed during a 180-min-long recovery in oxygenated medium. In perfused rat hindlimb muscles, hypoxia caused an increase in glucose transporters in the plasma membrane, suggesting that glucose transporter translocation plays a role in the stimulation of glucose transport by hypoxia. The maximal effects of hypoxia and insulin on glucose transport activity were additive, whereas the effects of exercise and hypoxia were not, providing evidence suggesting that hypoxia and exercise stimulate glucose transport by the same mechanism. Caffeine, at a concentration too low to cause muscle contraction or an increase in glucose transport by itself, markedly potentiated the effect of a submaximal hypoxic stimulus on sugar transport. Dantrolene significantly inhibited the hypoxia-induced increase in 3-O-methylglucose transport. These effects of caffeine and dantrolene suggest that Ca2+ plays a role in the stimulation of glucose transport by hypoxia.

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Effect of glucose-6-phosphate and pH on glucose transport in skeletal muscle plasma membrane giant vesicles

Acta Physiologica Scandinavica ◽

10.1111/j.1748-1716.1994.tb09680.x ◽

1994 ◽

Vol 150 (2) ◽

pp. 227-233 ◽

Cited By ~ 7

Author(s):

S. KRISTIANSEN ◽

J. F. WOJTASZEWSKI ◽

C. JUEL ◽

E. A. RICHTER

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Glucose Transport ◽

Giant Vesicles ◽

Muscle Plasma Membrane ◽

Effect Of Glucose

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Glucose-induced insulin resistance of skeletal-muscle glucose transport and uptake

Biochemical Journal ◽

10.1042/bj2520733 ◽

1988 ◽

Vol 252 (3) ◽

pp. 733-737 ◽

Cited By ~ 55

Author(s):

E A Richter ◽

B F Hansen ◽

S A Hansen

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Glucose Transport ◽

Muscle Glycogen ◽

Insulin Action ◽

Insulin Stimulation ◽

Initial Values ◽

Muscle Glucose Transport ◽

Glycogen Stores ◽

Effect Of Glucose

The ability of glucose and insulin to modify insulin-stimulated glucose transport and uptake was investigated in perfused skeletal muscle. Here we report that perfusion of isolated rat hindlimbs for 5 h with 12 mM-glucose and 20,000 microunits of insulin/ml leads to marked, rapidly developing, impairment of insulin action on muscle glucose transport and uptake. Thus maximal insulin-stimulated glucose uptake at 12 mM-glucose decreased from 34.8 +/- 1.9 to 11.5 +/- 1.1 mumol/h per g (mean +/- S.E.M., n = 10) during 5 h perfusion. This decrease in glucose uptake was accompanied by a similar change in muscle glucose transport as measured by uptake of 3-O-[14C]-methylglucose. Simultaneously, muscle glycogen stores increased to 2-3.5 times initial values, depending on fibre type. Perfusion for 5 h in the presence of glucose but in the absence of insulin decreased subsequent insulin action on glucose uptake by 80% of the effect of glucose with insulin, but without an increase in muscle glycogen concentration. Perfusion for 5 h with insulin but without glucose, and with subsequent addition of glucose back to the perfusate, revealed glucose uptake and transport similar to initial values obtained in the presence of glucose and insulin. The data indicate that exposure to a moderately increased glucose concentration (12 mM) leads to rapidly developing resistance of skeletal-muscle glucose transport and uptake to maximal insulin stimulation. The effect of glucose is enhanced by simultaneous insulin exposure, whereas exposure for 5 h to insulin itself does not cause measurable resistance to maximal insulin stimulation.

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Chronic renin inhibition with aliskiren improves glucose tolerance, insulin sensitivity, and skeletal muscle glucose transport activity in obese Zucker rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00448.2011 ◽

2012 ◽

Vol 302 (1) ◽

pp. R137-R142 ◽

Cited By ~ 19

Author(s):

Elizabeth M. Marchionne ◽

Maggie K. Diamond-Stanic ◽

Mujalin Prasonnarong ◽

Erik J. Henriksen

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Insulin Sensitivity ◽

Glucose Tolerance ◽

Glucose Transport ◽

Insulin Action ◽

Whole Body ◽

Zucker Rats ◽

Obese Zucker Rats ◽

Renin Inhibition

We have demonstrated previously that overactivity of the renin-angiotensin system (RAS) is associated with whole body and skeletal muscle insulin resistance in obese Zucker ( fa/fa) rats. Moreover, this obesity-associated insulin resistance is reduced by treatment with angiotensin-converting enzyme inhibitors or angiotensin receptor (type 1) blockers. However, it is currently unknown whether specific inhibition of renin itself, the rate-limiting step in RAS functionality, improves insulin action in obesity-associated insulin resistance. Therefore, the present study assessed the effect of chronic, selective renin inhibition using aliskiren on glucose tolerance, whole body insulin sensitivity, and insulin action on the glucose transport system in skeletal muscle of obese Zucker rats. Obese Zucker rats were treated for 21 days with either vehicle or aliskiren (50 mg/kg body wt ip). Renin inhibition was associated with a significant lowering (10%, P < 0.05) of resting systolic blood pressure and induced reductions in fasting plasma glucose (11%) and free fatty acids (46%) and homeostatic model assessment for insulin resistance (13%). Glucose tolerance (glucose area under the curve) and whole body insulin sensitivity (inverse of the glucose-insulin index) during an oral glucose tolerance test were improved by 15% and 16%, respectively, following chronic renin inhibition. Moreover, insulin-stimulated glucose transport activity in isolated soleus muscle of renin inhibitor-treated animals was increased by 36% and was associated with a 2.2-fold greater Akt Ser473 phosphorylation. These data provide evidence that chronic selective inhibition of renin activity leads to improvements in glucose tolerance and whole body insulin sensitivity in the insulin-resistant obese Zucker rat. Importantly, chronic renin inhibition is associated with upregulation of insulin action on skeletal muscle glucose transport, and it may involve improved Akt signaling. These data support the strategy of targeting the RAS to improve both blood pressure regulation and insulin action in conditions of insulin resistance.

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Skeletal muscle plasma membrane glucose transport and glucose transporters after exercise

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.1.193 ◽

1990 ◽

Vol 68 (1) ◽

pp. 193-198 ◽

Cited By ~ 96

Author(s):

L. J. Goodyear ◽

M. F. Hirshman ◽

P. A. King ◽

E. D. Horton ◽

C. M. Thompson ◽

...

Keyword(s):

Skeletal Muscle ◽

Plasma Membrane ◽

Glucose Uptake ◽

Glucose Transport ◽

Time Course ◽

Plasma Membranes ◽

Glucose Transporter ◽

Male Rats ◽

Intrinsic Activity ◽

Plasma Membrane Vesicles

Recent reports have shown that immediately after an acute bout of exercise the glucose transport system of rat skeletal muscle plasma membranes is characterized by an increase in both glucose transporter number and intrinsic activity. To determine the duration of the exercise response we examined the time course of these changes after completion of a single bout of exercise. Male rats were exercised on a treadmill for 1 h (20 m/min, 10% grade) or allowed to remain sedentary. Rats were killed either immediately or 0.5 or 2 h after exercise, and red gastrocnemius muscle was used for the preparation of plasma membranes. Plasma membrane glucose transporter number was elevated 1.8- and 1.6-fold immediately and 30 min after exercise, although facilitated D-glucose transport in plasma membrane vesicles was elevated 4- and 1.8-fold immediately and 30 min after exercise, respectively. By 2 h after exercise both glucose transporter number and transport activity had returned to nonexercised control values. Additional experiments measuring glucose uptake in perfused hindquarter muscle produced similar results. We conclude that the reversal of the increase in glucose uptake by hindquarter skeletal muscle after exercise is correlated with a reversal of the increase in the glucose transporter number and activity in the plasma membrane. The time course of the transport-to-transporter ratio suggests that the intrinsic activity response reverses more rapidly than that involving transporter number.

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