Vitamin C enters mitochondria via facilitative glucose transporter 1 (Glut1) and confers mitochondrial protection against oxidative injury Journal Article
| Authors: | Kc, S.; Cárcamo, J. M.; Golde, D. W. |
| Article Title: | Vitamin C enters mitochondria via facilitative glucose transporter 1 (Glut1) and confers mitochondrial protection against oxidative injury |
| Abstract: | Reactive oxygen species (ROS)-induced mitochondrial abnormalities may have important consequences in the pathogenesis of degenerative diseases and cancer. Vitamin C is an important antioxidant known to quench ROS, but its mitochondrial transport and functions are poorly understood. We found that the oxidized form of vitamin C, dehydroascorbic acid (DHA), enters mitochondria via facilitative glucose transporter 1 (Glut1) and accumulates mitochondrially as ascorbic acid (mtAA). The stereo-selective mitochondrial uptake of D-glucose, with its ability to inhibit mitochondrial DHA uptake, indicated the presence of mitochondrial Glut. Computational analysis of N-termini of human Glut isoforms indicated that Glut1 had the highest probability of mitochondrial localization, which was experimentally verified via mitochondrial expression of Glut1-EGFP. In vitro mitochondrial import of Glut1, immunoblot analysis of mitochondrial proteins, and cellular immunolocalization studies indicated that Glut1 localizes to mitochondria. Loading mitochondria with AA quenched mitochondrial ROS and inhibited oxidative mitochondrial DNA damage. mtAA inhibited oxidative stress resulting from rotenone-induced disruption of the mitochondrial respiratory chain and prevented mitochondrial membrane depolarization in response to a protonophore, CCCP. Our results show that analogous to the cellular uptake, vitamin C enters mitochondria in its oxidized form via Glut1 and protects mitochondria from oxidative injury. Since mitochondria contribute significantly to intracellular ROS, protection of the mitochondrial genome and membrane may have pharmacological implications against a variety of ROS-mediated disorders. © FASEB. |
| Keywords: | controlled study; human cell; nonhuman; protein localization; animal cell; animals; mice; dna damage; models, biological; oxygen; cell line; drug effect; dose-response relationship, drug; cell line, tumor; amino acid sequence; molecular sequence data; sequence homology, amino acid; amino terminal sequence; cell strain hek293; probability; cell membrane; immunoblotting; reactive oxygen species; reactive oxygen metabolite; cellular distribution; green fluorescent proteins; microscopy, fluorescence; genome; protein structure, tertiary; glucose; oxidative stress; antioxidants; ascorbic acid; software; mitochondrial membrane; dna, mitochondrial; mitochondria; mitochondrion; protein isoforms; cell strain 3t3; nih 3t3 cells; dehydroascorbic acid; oxidation reduction reaction; oxidation-reduction; degenerative disease; stereochemistry; glucose transporter 1; glucose transporter type 1; mitochondrial dna; enhanced green fluorescent protein; ros; electron transport; membrane potentials; protection; membrane depolarization; hl-60 cells; immunolocalization; cellular redox; ascorbic acid derivative; carbonyl cyanide chlorophenylhydrazone; carbonyl cyanide m-chlorophenyl hydrazone; rotenone |
| Journal Title: | FASEB Journal |
| Volume: | 19 |
| Issue: | 12 |
| ISSN: | 0892-6638 |
| Publisher: | Federation of American Societies for Experimental Biology |
| Date Published: | 2005-10-01 |
| Start Page: | 1657 |
| End Page: | 1667 |
| Language: | English |
| DOI: | 10.1096/fj.05-4107com |
| PUBMED: | 16195374 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | --- - "Cited By (since 1996): 44" - "Export Date: 24 October 2012" - "CODEN: FAJOE" - "Source: Scopus" |
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