Fig. 4.

LPS-induced autophagy is mediated by oxidative stress. A: GFP-LC3-expressing HL-1 cells were preincubated with 2 mM N-acetyl-cysteine (NAC) for 2 h before 4 h incubation with 1 μg/ml LPS. Cells were fixed, and GFP-positive cells were scored for autophagy. Data are means ± SE of 3 independent experiments. *P < 0.01 compared with control; **P < 0.001 compared with LPS. B: GFP-LC3 HL-1 cells were preincubated without or with NAC before addition of 100 μM H₂O₂ or 200 μM sodium nitroprusside (SNP) for 4 h. Data are means ± SE of 3 independent experiments. *P < 0.01; **P < 0.001 compared with H₂O₂ or SNP.