Derlin-1 Regulates Mutant VCP-Linked Pathogenesis and Endoplasmic Reticulum Stress-Induced Apoptosis
Figure 5
Derlin-1 involves in ER stress-induced caspase activation.
(A) Confocal images of GMR>CD8-PARP-Venus eye discs treated with 5 mM DTT for 1-, 2- and 3.5-hrs. In the lower row, Derlin-1 expression is reduced by derlin-1 RNAi. The eye discs are stained with anti-PARP (red) and anti-Elav (blue) to mark activated caspase activity and neuronal nuclei, respectively. The anti-PARP signals are shown separately from the merged images for comparison. (B) Quantification of anti-PARP puncta from DTT-treated eye discs shown in A. For each eye disc, anti-PARP signals were normalized to the disc size (numbers of PARP puncta/rows of ommatidia), and ten eye discs for each time point was plotted. (C) Confocal images of wild-type and derlin-1null eye discs stained with anti-Elav (red) and anti-cleaved caspase-3 (green) antibodies. The eye discs in the right panels were treated with 5 mM DTT for 2 hours. The caspase-3 signals are shown separately from the merged images for comparison. (D) Quantification of anti-cleaved caspase-3 puncta as shown in C. Punta numbers were normalized to the disc size as described in B. Seven eye discs were analyzed. Values shown in B and D represent mean ± SE. *p<0.05; ***p<0.001 (Student's t-test). (E) Confocal images of GMR>LacZ (upper row) and GMR>derlin-1 (lower row) eyes at the larval, pupal, and adult stages, stained with anti-Elav antibodies to label photoreceptor nuclei (blue). These eyes carry a membrane-tethered CD8-PARP-Venus (green), and are stained with anti-PARP antibodies (red) to detect caspase-mediated cleavage events. Scale bars: 10 µm. (F) Confocal images of larval, pupal, and adult GMR>LacZ (upper row) and GMR>derlin-1 (lower row) eyes stained with anti-Elav (red) and anti-cleaved caspase-3 (green) antibodies. Scale bars: 10 µm.