Figure 5.

p38 inhibitor confers protection against MPP⁺ mediated cell death by preventing p53 translocation into the nucleus. A, Cells treated with SB239063 (1 μm) for 60 min before exposure to MPP⁺ (10 μm) for 24 h were protected from MPP⁺ mediated cell death. Scale bar, 200 μm. Cells were treated with either vehicle or SB239063 before the treatment with MPP⁺, quantification represents percentage of cells positive for TUNEL staining per total number of cells as represented by DAPI staining. B, p53 inhibitor pifithrin-α confers protection against MPP⁺ mediated cell death. Cells treated with pifithrin-α (250 nm) for 60 min before exposure to MPP⁺ (10 μm) for 24 h were not affected by MPP⁺ mediated cell death. Scale bar, 200 μm. Cells were treated with either vehicle or pifithrin-α before the treatment with MPP⁺, quantification represents, percentage of cells positive for TUNEL staining per total number of cells as represented by DAPI count. C, p53, localized in the cytoplasm in primary neurons under control condition translocated into the nucleus in response to MPP⁺ exposure. The nuclear translocation was prevented by pretreating the cells with p38 inhibitor, SB239063. D, Nuclear translocation was partially prevented by pretreating the cells with JNK inhibitor, SP600125 (panel 4). Total number of cells is represented by propidium iodide (PI) staining. Data are represented as mean ± SD of four independent experiments. Asterisks indicate values significantly different from controls (p < 0.05).