Dihydroceramide desaturase activity is modulated by oxidative stress.
Oxidative stress has been implicated previously in the regulation of ceramide metabolism. In the present study, its effects on dihydroceramide desaturase were investigated. To stimulate oxidative stress, HEK (human embyronic kidney)-293, MCF7, A549 and SMS-KCNR cells were treated with H2O2, menadione or tert-butylhydroperoxide. In all cell lines, an increase in dihydroceramide was observed upon oxidative stress as measured by LC (liquid chromatography)/MS. In contrast, total ceramide levels were relatively unchanged. Mechanistically, dihydroceramide desaturase activity was measured by an in situ assay and decreased in a time- and dose-dependent fashion. Interestingly, no detectable changes in the protein levels were observed, suggesting that oxidative stress does not induce degradation of dihydroceramide desaturase. In summary, oxidative stress leads to potent inhibition of dihydroceramide desaturase resulting in significant elevation in dihydroceramide levels in vivo.
Idkowiak-Baldys
Jolanta
J
Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, 29425, USA.
Apraiz
Aintzane
A
Li
Li
L
Rahmaniyan
Mehrdad
M
Clarke
Christopher J
CJ
Kraveka
Jacqueline M
JM
Asumendi
Aintzane
A
Hannun
Yusuf A
YA
D002460:Cell Line; D002518:Ceramides / Q000032:analysis; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects; D010088:Oxidoreductases / Q000032:analysis / Q000378:metabolism*; D055550:Protein Stability
D002518:Ceramides; C109343:dihydroceramide; D010088:Oxidoreductases; C108138:dihydroceramide desaturase