Effects of IFN- γ , AA, BPB, Pertussis Toxin, and Herbimycin A on Sphingomyelin and Ceramide Levels in HL-60 Cells
| Treatment . | Sphingomyelin (% control) . | Ceramide (pmol/mg of protein) . | ||||
|---|---|---|---|---|---|---|
| . | Control . | IFN-γ . | AA . | Control . | IFN-γ . | AA . |
| None | 100 ± 3.7 | 74.2 ± 5.33-150 | 73.8 ± 5.13-150 | 18.3 ± 1.9 | 41.5 ± 3.93-150 | 44.2 ± 4.33-150 |
| BPB | 102.1 ± 5.3 | 97.6 ± 4.2 | 74.1 ± 4.23-150 | 17.9 ± 1.6 | 18.1 ± 1.7 | 43.7 ± 3.63-150 |
| Pertussis toxin | 103.2 ± 4.3 | 102.1 ± 3.7 | 73.7 ± 3.63-150 | 17.5 ± 2.2 | 19.1 ± 2.1 | 42.8 ± 5.13-150 |
| Herbimycin A | 101.5 ± 3.7 | 75.6 ± 4.23-150 | ND | 18.5 ± 2.1 | 42.1 ± 4.33-150 | ND |
| Treatment . | Sphingomyelin (% control) . | Ceramide (pmol/mg of protein) . | ||||
|---|---|---|---|---|---|---|
| . | Control . | IFN-γ . | AA . | Control . | IFN-γ . | AA . |
| None | 100 ± 3.7 | 74.2 ± 5.33-150 | 73.8 ± 5.13-150 | 18.3 ± 1.9 | 41.5 ± 3.93-150 | 44.2 ± 4.33-150 |
| BPB | 102.1 ± 5.3 | 97.6 ± 4.2 | 74.1 ± 4.23-150 | 17.9 ± 1.6 | 18.1 ± 1.7 | 43.7 ± 3.63-150 |
| Pertussis toxin | 103.2 ± 4.3 | 102.1 ± 3.7 | 73.7 ± 3.63-150 | 17.5 ± 2.2 | 19.1 ± 2.1 | 42.8 ± 5.13-150 |
| Herbimycin A | 101.5 ± 3.7 | 75.6 ± 4.23-150 | ND | 18.5 ± 2.1 | 42.1 ± 4.33-150 | ND |
[3H]Choline-labeled or unlabeled HL-60 cells were preincubated with BPB (10 μmol/L) for 10 minutes, pertussis toxin (20 ng/mL) for 18 hours or herbimycin A (1 μg/mL) for 14 hours and then treated or not with either IFN-γ (2,000 U/mL) or AA (10 μmol/L) for 2 hours. After incubation, cells were harvested, lipids were extracted, and SM levels were determined by TLC, while ceramide levels were determined using DAG kinase assay. The data (means ± SD) are from three independent experiments assayed in duplicate.
Abbreviation: ND, not determined.
Significantly different (P < .05, Student's t-test) from controls.