Fig. 4.

Atg5-dependent autophagy protects against MPP⁺-induced dopaminergic cell death. A and B, Cells were subjected to 1h pretreatment with rapamycin (5μM), wortmannin (200nM), or trehalose (100mM). In (C), cells were infected with Ad-Empty or Ad-dnAtg5 at 1.5 MOI for 24h. Then, cells were treated with MPP⁺ (2.5mM) for additional 48h. Loss of cell viability or plasma membrane integrity was determined by measurement of released LDH activity (A and C) or by PI uptake by flow cytometry (B) as explained in Figure 3. Histograms in (A) are representative of 3 independent experiments. Data in bar graphs represent percentage of released LDH activity, and are means ± SEM of 3 independent experiments. *p < .05, significant difference with respect to MPP⁺-only treatment. Abbreviations: dnAtg5, dominant negative form of Atg5; LDH, lactate dehydrogenase; MOI, multiplicity of infection; MPP⁺ _, 1-methyl-4-phenylpyridinium; PI, propidium iodide.