Amelioration of palmitate-induced metabolic dysfunction in L6 muscle cells expressing low levels of receptor-interacting protein 140

We have shown that reduced expression of receptor-interacting protein 140 (RIP140) alters the regulation of fatty-acid (FA) oxidation in muscle. To determine whether a high level of FA availability alters the effects of RIP140 on metabolic regulation, L6 myotubes were transfected with or without RNA interference oligonucleotide sequences to reduce RIP140 expression, and then incubated with high levels of palmitic acid, with or without insulin. High levels of palmitate reduced basal (53%–58%) and insulin-treated (24%–44%) FA uptake and oxidation, and increased basal glucose uptake (88%). In cells incubated with high levels of palmitate, low RIP140 increased basal FA uptake and insulin-treated FA oxidation and glucose uptake, and decreased basal glucose uptake and insulin-treated FA uptake. Under basal conditions, low RIP140 increased the mRNA content of FAT/CD36 (159%) and COX4 (61%), as well as the protein content of Nur77 (68%), whereas the mRNA expression of FGF21 (50%) was decreased, as was the protein content of CPT1b (35%) and FGF21 (44%). Under insulin-treated conditions, low RIP140 expression increased the mRNA content of MCAD (84%) and Nur77 (84%), as well as the protein content of Nur77 (23%). Thus, a low level of RIP140 restores the rates of FA uptake in the basal state, in part via a reduction in upstream insulin signaling. Our data also indicate that the protein expression of Nur77 may be modulated by RIP140 when muscle cells are metabolically challenged by high levels of palmitate.

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Unique mechanism of GLUT3 glucose transporter regulation by prolonged energy demand: increased protein half-life

Biochemical Journal ◽

10.1042/bj3330713 ◽

1998 ◽

Vol 333 (3) ◽

pp. 713-718 ◽

Cited By ~ 42

Author(s):

Zayna A. KHAYAT ◽

Anthony L. McCALL ◽

Amira KLIP

Keyword(s):

Glucose Uptake ◽

Protein Content ◽

Glucose Transport ◽

Half Life ◽

Glucose Transporter ◽

Muscle Cells ◽

Mrna Levels ◽

Glut1 Protein ◽

L6 Muscle Cells

L6 muscle cells survive long-term (18 h) disruption of oxidative phosphorylation by the mitochondrial uncoupler 2,4-dinitrophenol (DNP) because, in response to this metabolic stress, they increase their rate of glucose transport. This response is associated with an elevation of the protein content of glucose transporter isoforms GLUT3 and GLUT1, but not GLUT4. Previously we have reported that the rise in GLUT1 expression is likely to be a result of de novo biosynthesis of the transporter, since the uncoupler increases GLUT1 mRNA levels. Unlike GLUT1, very little is known about how interfering with mitochondrial ATP production regulates GLUT3 protein expression. Here we examine the mechanisms employed by DNP to increase GLUT3 protein content and glucose uptake in L6 muscle cells. We report that, in contrast with GLUT1, continuous exposure to DNP had no effect on GLUT3 mRNA levels. DNP-stimulated glucose transport was unaffected by the protein-synthesis inhibitor cycloheximide. The increase in GLUT3 protein mediated by DNP was also insensitive to cycloheximide, paralleling the response of glucose uptake, whereas the rise in GLUT1 protein levels was blocked by the inhibitor. The GLUT3 glucose transporter may therefore provide the majority of the glucose transport stimulation by DNP, despite elevated levels of GLUT1 protein. The half-lives of GLUT3 and GLUT1 proteins in L6 myotubes were determined to be about 15 h and 6 h respectively. DNP prolonged the half-life of both proteins. After 24 h of DNP treatment, 88% of GLUT3 protein and 57% of GLUT1 protein had not turned over, compared with 25% in untreated cells. We conclude that the long-term stimulation of glucose transport by DNP arises from an elevation of GLUT3 protein content associated with an increase in GLUT3 protein half-life. These findings suggest that disruption of the oxidative chain of L6 muscle cells leads to an adaptive response of glucose transport that is distinct from the insulin response, involving specific glucose transporter isoforms that are regulated by different mechanisms.

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Bergenin from Cissus javana DC. (Vitaceae) root extract enhances glucose uptake by rat L6 myotubes

Tropical Journal of Pharmaceutical Research ◽

10.4314/tjpr.v19i5.25 ◽

2020 ◽

Vol 19 (5) ◽

pp. 1081-1086

Author(s):

Htoo Tint San ◽

Panitch Boonsnongchee ◽

Waraporn Putalun ◽

Boonchoo Sritularak ◽

Kittisak Likhitwitayawuid

Keyword(s):

Glucose Uptake ◽

Inhibitory Activity ◽

Methanol Extract ◽

Chemical Constituents ◽

Muscle Cells ◽

Chemical Components ◽

Root Extract ◽

Rat Skeletal Muscle ◽

L6 Myotubes ◽

Tuberous Roots

Purpose: To examine the glucose uptake stimulatory activity of the root extract of Cissus javana DC. (Vitaceae) in Lδ myotubes of rat, and also to identify the extract’s active principles.Methods: The methanol extract was prepared from Cissus javana tuberous roots and evaluated for glucose uptake stimulatory effects on Lδ rat muscle cells and inhibitory activity against α-glucosidase. The chemical components were isolated using several chromatographic techniques, and their structures characterized by spectroscopic methods. Each isolate was then assayed for glucose uptake stimulatory and α-glucosidase inhibitory activities.Results: The extract (100 μg/ml) exhibited glucose uptake stimulatory effect (70.9 % enhancement) and α-glucosidase enzyme inhibitory activity (100 % inhibition). Through chromatographic separation, bergenin, stigmast-4-en-3-one and β-sitosterol were isolated and identified. Bergenin, at 100 μg/ml (0.3046 mM), increased glucose uptake by Lδ myotubes by 50.5 % without toxicity. At the same concentration, bergenin showed no inhibition on α-glucosidase enzyme, while stigmast-4-en-3-one and β-sitosterol exhibited 98.6 and 40.6 %, inhibition, respectively.Conclusion: This study is the first report on the chemical constituents, and the glucose uptake stimulatory and α-glucosidase inhibitory activities of Cissus javana DC. roots. The findings reveal the antidiabetic potential of the plant and the glucose-uptake enhancing activity of bergenin. Keywords: Cissus javana, α-Glucosidase, Antidiabetes, Rat skeletal muscle cells, Bergenin

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(S)-[6]-Gingerol enhances glucose uptake in L6 myotubes by activation of AMPK in response to [Ca2+]i

Journal of Pharmacy & Pharmaceutical Sciences ◽

10.18433/j34g7p ◽

2013 ◽

Vol 16 (2) ◽

pp. 304 ◽

Cited By ~ 21

Author(s):

Yiming Li ◽

Van H Tran ◽

Nooshin Koolaji ◽

Colin Duke ◽

Basil D Roufogalis

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Zingiber Officinale ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Dependent Protein Kinase ◽

L6 Myotubes ◽

Dependent Protein ◽

L6 Skeletal Muscle Cells ◽

Protein Kinase Kinase

PURPOSE. The aim of this study was to investigate the mechanism of (S)-[6]-gingerol in promoting glucose uptake in L6 skeletal muscle cells. METHODS. The effect of (S)-[6]-gingerol on glucose uptake in L6 myotubes was examined using 2-[1,2-3H]-deoxy-D-glucose. Intracellular Ca2+ concentration was measured using Fluo-4. Phosphorylation of AMPKα was determined by Western blotting analysis. RESULTS. (S)-[6]-Gingerol time-dependently enhanced glucose uptake in L6 myotubes. (S)-[6]-Gingerol elevated intracellular Ca2+ concentration and subsequently induced a dose- and time-dependent enhancement of threonine172 phosphorylated AMPKα in L6 myotubes via modulation by Ca2+/calmodulin-dependent protein kinase kinase. CONCLUSION. The results indicated that (S)-[6]-gingerol increased glucose uptake in L6 skeletal muscle cells by activating AMPK. (S)-[6]-gingerol, a major component of Zingiber officinale, may have potential for development as an antidiabetic agent. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

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Stimulation of AMP-activated protein kinase and enhancement of basal glucose uptake in muscle cells by quercetin and quercetin glycosides, active principles of the antidiabetic medicinal plant Vaccinium vitis-idaea

Molecular Nutrition & Food Research ◽

10.1002/mnfr.200900218 ◽

2010 ◽

Vol 54 (7) ◽

pp. 991-1003 ◽

Cited By ~ 104

Author(s):

Hoda M. Eid ◽

Louis C. Martineau ◽

Ammar Saleem ◽

Asim Muhammad ◽

Diane Vallerand ◽

...

Keyword(s):

Protein Kinase ◽

Medicinal Plant ◽

Glucose Uptake ◽

Muscle Cells ◽

Quercetin Glycosides ◽

Amp Activated Protein Kinase ◽

Basal Glucose Uptake ◽

Stimulation Of

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Effect of Sucralose on Glucose Uptake in Rat L6 Myotubes

Indian Journal of Medical Biochemistry ◽

10.5005/jp-journals-10054-0042 ◽

2017 ◽

Vol 21 (2) ◽

pp. 162-165

Author(s):

Shubha N Prakash ◽

Jayakumari Shanthakumari ◽

Anitha Devanath

Keyword(s):

Insulin Resistance ◽

Cell Culture ◽

Glucose Uptake ◽

Cell Line ◽

Artificial Sweeteners ◽

Public Concern ◽

Insulin Stimulation ◽

L6 Myotubes ◽

Sugar Levels ◽

Basal Glucose Uptake

ABSTRACT Introduction With growing awareness of the link between diet and health and the problem of obesity, public concern over sugar levels in the diet is forcing a worldwide trend toward cutting down on sugar by using artificial sweeteners (AS). Aim To study the effect of increasing concentrations of sucralose (an AS) on glucose uptake in rat L6 myotubes. Materials and methods The L6 cell line from American type cell culture (ATCC) was grown in Dulbecco's Modified Eagle's Medium (DMEM) and differentiated into myotubes. The wells were exposed to either 0, 1 nM, 1 μM, or 1 mM of sucralose alone or with 10 nM insulin for 24 hours. Glucose uptake was studied after this period. Results Significant decrease was seen between the insulin-stimulated basal glucose uptake and insulin-stimulated glucose uptake across all the concentrations of sucralose treatment. Conclusion Increased concentration of sucralose appears to decrease glucose uptake even on insulin stimulation. Clinical significance It may not be beneficial to use sucralose in certain groups of people who have insulin resistance or are prone to it. How to cite this article Prakash SN, Shanthakumari J, Devanath A. Effect of Sucralose on Glucose Uptake in Rat L6 Myotubes. Indian J Med Biochem 2017;21(2):162-165.

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Carnosic Acid Attenuates the Free Fatty Acid-Induced Insulin Resistance in Muscle Cells and Adipocytes

Cells ◽

10.3390/cells11010167 ◽

2022 ◽

Vol 11 (1) ◽

pp. 167

Author(s):

Danja J. Den Hartogh ◽

Filip Vlavcheski ◽

Adria Giacca ◽

Rebecca E. K. MacPherson ◽

Evangelia Tsiani

Keyword(s):

Insulin Resistance ◽

Glucose Uptake ◽

Muscle Cells ◽

Serine Phosphorylation ◽

Carnosic Acid ◽

Rosemary Extract ◽

Fat Cell ◽

Insulin Resistant ◽

L6 Myotubes ◽

P70 S6k

Elevated blood free fatty acids (FFAs), as seen in obesity, impair insulin action leading to insulin resistance and Type 2 diabetes mellitus. Several serine/threonine kinases including JNK, mTOR, and p70 S6K cause serine phosphorylation of the insulin receptor substrate (IRS) and have been implicated in insulin resistance. Activation of AMP-activated protein kinase (AMPK) increases glucose uptake, and in recent years, AMPK has been viewed as an important target to counteract insulin resistance. We reported previously that carnosic acid (CA) found in rosemary extract (RE) and RE increased glucose uptake and activated AMPK in muscle cells. In the present study, we examined the effects of CA on palmitate-induced insulin-resistant L6 myotubes and 3T3L1 adipocytes. Exposure of cells to palmitate reduced the insulin-stimulated glucose uptake, GLUT4 transporter levels on the plasma membrane, and Akt activation. Importantly, CA attenuated the deleterious effect of palmitate and restored the insulin-stimulated glucose uptake, the activation of Akt, and GLUT4 levels. Additionally, CA markedly attenuated the palmitate-induced phosphorylation/activation of JNK, mTOR, and p70S6K and activated AMPK. Our data indicate that CA has the potential to counteract the palmitate-induced muscle and fat cell insulin resistance.

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Gliclazide treatment of streptozotocin diabetic rats restores GLUT4 protein content and basal glucose uptake in skeletal muscle

Metabolism ◽

10.1016/s0026-0495(97)90310-3 ◽

1997 ◽

Vol 46 ◽

pp. 10-13 ◽

Cited By ~ 26

Author(s):

Nieves Pulido ◽

Ana Suarez ◽

Benito Casanova ◽

Remedios Romero ◽

Esther Rodriguez ◽

...

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Protein Content ◽

Diabetic Rats ◽

Streptozotocin Diabetic Rats ◽

Basal Glucose Uptake

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β-Sitosterol-D-Glucopyranoside Mimics Estrogenic Properties and Stimulates Glucose Utilization in Skeletal Muscle Cells

Molecules ◽

10.3390/molecules26113129 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3129

Author(s):

Jyotsana Pandey ◽

Kapil Dev ◽

Sourav Chattopadhyay ◽

Sleman Kadan ◽

Tanuj Sharma ◽

...

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Glucose Utilization ◽

Diabetes Management ◽

Expression System ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Cell Periphery ◽

Glut4 Translocation ◽

In Silico Docking

Estrogenic molecules have been reported to regulate glucose homeostasis and may be beneficial for diabetes management. Here, we investigated the estrogenic effect of β-sitosterol-3-O-D-glucopyranoside (BSD), isolated from the fruits of Cupressus sempervirens and monitored its ability to regulate glucose utilization in skeletal muscle cells. BSD stimulated ERE-mediated luciferase activity in both ERα and ERβ-ERE luc expression system with greater response through ERβ in HEK-293T cells, and induced the expression of estrogen-regulated genes in estrogen responsive MCF-7 cells. In silico docking and molecular interaction studies revealed the affinity and interaction of BSD with ERβ through hydrophobic interaction and hydrogen bond pairing. Furthermore, prolonged exposure of L6-GLUT4myc myotubes to BSD raised the glucose uptake under basal conditions without affecting the insulin-stimulated glucose uptake, the effect associated with enhanced translocation of GLUT4 to the cell periphery. The BSD-mediated biological response to increase GLUT4 translocation was obliterated by PI-3-K inhibitor wortmannin, and BSD significantly increased the phosphorylation of AKT (Ser-473). Moreover, BSD-induced GLUT4 translocation was prevented in the presence of fulvestrant. Our findings reveal the estrogenic activity of BSD to stimulate glucose utilization in skeletal muscle cells via PI-3K/AKT-dependent mechanism.

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