Role of GLUT1 in regulation of reactive oxygen species

Stanley Andrisse,Rikki M Koehler,Joseph E Chen,Gaytri D Patel,Vivek R Vallurupalli,Benjamin A Ratliff,Daniel E Warren,Jonathan S Fisher

doi:10.1016/j.redox.2014.03.004

Stanley Andrisse, Rikki M Koehler + Show 6 more

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https://doi.org/10.1016/j.redox.2014.03.004

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Journal: Redox Biology	Publication Date: Jan 1, 2014
Citations: 49	License type: cc-by

Affiliation: Saint Louis University

Abstract

In skeletal muscle cells, GLUT1 is responsible for a large portion of basal uptake of glucose and dehydroascorbic acid, both of which play roles in antioxidant defense. We hypothesized that conditions that would decrease GLUT1-mediated transport would cause increased reactive oxygen species (ROS) levels in L6 myoblasts, while conditions that would increase GLUT1-mediated transport would result in decreased ROS levels. We found that the GLUT1 inhibitors fasentin and phloretin increased the ROS levels induced by antimycin A and the superoxide generator pyrogallol. However, indinavir, which inhibits GLUT4 but not GLUT1, had no effect on ROS levels. Ataxia telangiectasia mutated (ATM) inhibitors and activators, previously shown to inhibit and augment GLUT1-mediated transport, increased and decreased ROS levels, respectively. Mutation of an ATM target site on GLUT1 (GLUT1-S490A) increased ROS levels and prevented the ROS-lowering effect of the ATM activator doxorubicin. In contrast, expression of GLUT1-S490D lowered ROS levels during challenge with pyrogallol, prevented an increase in ROS when ATM was inhibited, and prevented the pyrogallol-induced decrease in insulin signaling and insulin-stimulated glucose transport. Taken together, the data suggest that GLUT1 plays a role in regulation of ROS and could contribute to maintenance of insulin action in the presence of ROS.

Highlights

Reactive oxygen species (ROS) are a byproduct of metabolism, being produced, for example, during electron transfer in mitochondrial respiration [1]
To determine the effects of Glucose transporter 1 (GLUT1) inhibition on reactive oxygen species (ROS) levels, L6 myoblasts that had been loaded with DCFDA, a fluorescent ROS probe, were incubated in media plus and minus GLUT1 inhibitors, and oxidative stress was induced by antimycin A (Ant-A) or pyrogallol (PG)
In muscle cells, DCFDA loaded L6 myoblasts were incubated in the presence or absence of 100 μM indinavir, which inhibits GLUT4 but not GLUT1, and oxidative stress was induced by Ant-A or PG

Summary

Introduction

Reactive oxygen species (ROS) are a byproduct of metabolism, being produced, for example, during electron transfer in mitochondrial respiration [1]. ROS can serve as signaling molecules for metabolic processes including PI3K- and AMPK-independent glucose transport [2], PGCα-stimulated mitochondrial biogenesis [3], and regulation of muscle-derived cytokines [4]. Prolonged oxidative stress, as apparent in obesity and metabolic syndrome, is associated with an elevation in reactive oxygen species (ROS) [5]. Elevated levels of ROS have been shown to be associated with insulin resistance [6], a key feature of type 2 diabetes mellitus [7]. Mice fed a high-fat diet to induce insulin resistance displayed increased ROS levels in adipocytes and skeletal muscle [8]. Treatment with an antioxidant prevented insulin resistance caused by a high fat diet [8]

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