Fig. 3

DJ-1 expression is induced in zebrafish treated with H₂O₂ and knockdown of DJ-1 increases the number of apoptotic cells. A. Control MO injected embryos showed normal distribution of islet-1 positive neurons along the spinal cord, as illustrated by the dorsal view of the spinal cord, anterior to the top of the image. B. Control MO injected embryos treated with H₂O₂ showed a slight reduction in islet-1 staining. C. DJ-1 MO injected embryos displayed even weaker islet-1 staining. D-F. Control MO (D, E) or DJ-1 MO (F) was injected into embryos at one cell stage; after 24 hr, control MO injected embryos were treated with 0.03% H₂O₂ for 30 min. Compared to control MO injected embryos (D), there was an increase of TUNEL positive cells in the tails of H₂O₂ treated embryos (E) and DJ-1 MO injected embryos (F). The lateral view of the trunk region of zebrafish was illustrated with anterior to the left of the image. The number of apoptotic cells in the tails of H₂O₂ treated embryos (E) and DJ-1 KD embryos (F) is higher than that in control MO injected embryos (D). G. Adult zebrafish were treated with 0.03% H₂O₂ for 30 min before brains were harvested and lysed for Western blot. α-Tubulin (an internal sample loading control) was detected over the upper portion of the blot, and the bottom portion of the blot was detected with antibody DJ-1-N. While the levels of α-tubulin were not changed in the presence of H₂O₂, the levels of DJ-1 were increased.