Characterization of a rat NADPH-dependent aldo-keto reductase (AKR1B13) induced by oxidative stress.
A rat aldo-keto reductase (AKR1B13) was identified as a hepatoma-derived protein, exhibiting high sequence identity with mouse fibroblast growth factor (FGF)-induced reductase, AKR1B8. In this study, AKR1B13 was characterized in terms of its enzymatic properties, tissue distribution and regulation. Recombinant AKR1B13 exhibited NADPH-linked reductase activity towards various aldehydes and alpha-dicarbonyl compounds, which include reactive compounds such as methylglyoxal, glyoxal, acrolein, 4-hydroxynonenal and 3-deoxyglucosone. The enzyme exhibited low NADP(+)-linked dehydrogenase activity towards aliphatic and aromatic alcohols, and was inhibited by aldose reductase inhibitors, flavonoids, benzbromarone and hexestrol. Immunochemical and reverse transcription-PCR analyses revealed that the enzyme is expressed in many rat tissues, endothelial cells and fibroblasts. Gene expression in YPEN-1 and NRK cells was up-regulated by treatments with submicromolar concentrations of hydrogen peroxide and 1,4-naphthoquinone, but not with FGF-1, FGF-2, 5alpha-dihydrotestosterone and 17beta-estradiol. These results indicate that AKR1B13 differs from AKR1B8 in tissue distribution and gene regulation, and suggest that it functions as a defense system against oxidative stress in rat tissues.
Endo
Satoshi
S
Laboratory of Biochemistry, Gifu Pharmaceutical University, Gifu, Japan. sendo@gifu-pu.ac.jp
Matsunaga
Toshiyuki
T
Mamiya
Hiroaki
H
Hara
Akira
A
Kitade
Yukio
Y
Tajima
Kazuo
K
El-Kabbani
Ossama
O
D000449:Aldehyde Reductase / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D017931:DNA Primers; D018076:DNA, Complementary; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic; D016297:Mutagenesis, Site-Directed; D009249:NADP / Q000378:metabolism*; D018384:Oxidative Stress; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013379:Substrate Specificity
D017931:DNA Primers; D018076:DNA, Complementary; D011994:Recombinant Proteins; D009249:NADP; C538756:Akr1b8 protein, rat; D000449:Aldehyde Reductase