Sec-containing TrxR1 is essential for self-sufficiency of cells by control of glucose-derived H2O2.
It is commonly recognized that diabetic complications involve increased oxidative stress directly triggered by hyperglycemia. The most important cellular protective systems against such oxidative stress have yet remained unclear. Here we show that the selenoprotein thioredoxin reductase 1 (TrxR1), encoded by the Txnrd1 gene, is an essential enzyme for such protection. Individually grown Txnrd1 knockout (Txnrd1(-/-)) mouse embryonic fibroblasts (MEFs) underwent massive cell death directly linked to glucose-induced H2O2 production. This death and excessive H2O2 levels could be reverted by reconstituted expression of selenocysteine (Sec)-containing TrxR1, but not by expression of Sec-devoid variants of the enzyme. Our results show that Sec-containing TrxR1 is absolutely required for self-sufficient growth of MEFs under high-glucose conditions, owing to an essential importance of this enzyme for elimination of glucose-derived H2O2. To our knowledge, this is the first time a strict Sec-dependent function of TrxR1 has been identified as being essential for mammalian cells.
Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
X
X
Peng
1] Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, German Research Center for Environmental health, Marchioninistr. 25, 81377 Munich, Germany [2].
P K
PK
Mandal
Division of Toxicology, Institute of Environmental Medicine, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
V O
VO
Kaminskyy
Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
A
A
Lindqvist
Helmholtz Zentrum München, Institute of Developmental Genetics, Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
M
M
Conrad
Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
E S J
0000000248076114
ES
Arnér
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D016923:Cell Death; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005947:Glucose / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D018384:Oxidative Stress; D011994:Recombinant Proteins / Q000378:metabolism; D017279:Selenocysteine / Q000378:metabolism*; D015398:Signal Transduction; D054481:Thioredoxin Reductase 1 / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection
D000975:Antioxidants; D011994:Recombinant Proteins; D017279:Selenocysteine; D006861:Hydrogen Peroxide; C516124:TXNRD1 protein, human; D054481:Thioredoxin Reductase 1; C516125:Txnrd1 protein, mouse; C516126:Txnrd1 protein, rat; D005978:Glutathione; D005947:Glucose