TY - JOUR
T1 - Effects of endoglycoceramidase or D-threo-1-phenyl-2-decanoylamino-3- morpholino-1-propanol on glucose uptake, glycolysis, and mitochondrial respiration in HL60 cells
AU - Ji, Li
AU - Ito, Makoto
AU - Zhang, Gu
AU - Hirabayashi, Yoshio
AU - Inokuchi, Jin Ichi
AU - Yamagata, Tatsuya
PY - 1998/11/1
Y1 - 1998/11/1
N2 - The glycosphingolipid content of HL60 cells was reduced by endoglycoceramidase, an enzyme which specifically hydrolyzes glycosphingolipids on the cell surface, or by D-threo-1-phenyl-2- decanoylamino-3-morpholino-1-propanol, an inhibitor which specifically reduces the activity of UDP-glucose:ceramide glucosyltransferase. Reduction of the glycosphingolipid content by both reagents resulted in enhancement of glucose uptake and glycolysis. Neither of these effects was observed in the presence of cytochalasin B, an inhibitor of facilitated glucose transport. The uptake of radiolabeled 3-O-methylglucose by the cells was not affected by treatment with either of the reagents, indicating no activation of the glucose transporter. On the other hand, both reagents decreased the level of ATP and CO2 production. The molecule mediating these effects appeared to be ceramide, since both treatments actually increased the intracellular ceramide content, and the cell-permeable short-chain ceramide N-acetylsphingosine, but not sphingosine, sphinganine, or palmitic acid, mimicked the effects of both reagents to comparable extents. Finally, the function of electron transport in isolated mitochondria fractions was found to be reduced by treatment of the cells with N-acetylsphingosine. These results strongly suggest that ceramide may affect mitochondrial respiration.
AB - The glycosphingolipid content of HL60 cells was reduced by endoglycoceramidase, an enzyme which specifically hydrolyzes glycosphingolipids on the cell surface, or by D-threo-1-phenyl-2- decanoylamino-3-morpholino-1-propanol, an inhibitor which specifically reduces the activity of UDP-glucose:ceramide glucosyltransferase. Reduction of the glycosphingolipid content by both reagents resulted in enhancement of glucose uptake and glycolysis. Neither of these effects was observed in the presence of cytochalasin B, an inhibitor of facilitated glucose transport. The uptake of radiolabeled 3-O-methylglucose by the cells was not affected by treatment with either of the reagents, indicating no activation of the glucose transporter. On the other hand, both reagents decreased the level of ATP and CO2 production. The molecule mediating these effects appeared to be ceramide, since both treatments actually increased the intracellular ceramide content, and the cell-permeable short-chain ceramide N-acetylsphingosine, but not sphingosine, sphinganine, or palmitic acid, mimicked the effects of both reagents to comparable extents. Finally, the function of electron transport in isolated mitochondria fractions was found to be reduced by treatment of the cells with N-acetylsphingosine. These results strongly suggest that ceramide may affect mitochondrial respiration.
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U2 - 10.1006/abbi.1998.0883
DO - 10.1006/abbi.1998.0883
M3 - Article
C2 - 9799567
AN - SCOPUS:0032211207
VL - 359
SP - 107
EP - 114
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -