|
Fig. 6
Qx protects against ototoxin-induced HC death and promotes supporting cell proliferation. (A–I) TUNEL assay (red) was performed in zebrafish incubated with vehicle or 300 µM of Qx alone (controls) or with the corresponding ototoxin with or without Qx 300 µM. Animals were counterstained with phalloidin (green). (A) Neomycin (Neo) 200 µM incubation for 30 min. (B) Gentamicin (GM) 50 µM incubation for 1 hour. (C) Cisplatin (CP) 400 µM incubation for 2 hours. (D) GM 50 µM incubation for 1 hour followed by recovery for 5 hours. (E) Incubation with Qx 300 µM for 8 hours and Neo 200 µM for 30 min. (F) Incubation with Qx 300 µM for 8 hours and GM 50 µM for 1 hour. (G) Qx 300 µM for 8 hours + CP 400 µM for 2 hours. (H) Qx 300 µM incubation for 8 hours + GM 50 µM for 1 hour followed by 5 hours recovery. Asterisks denote TUNEL-positive HCs. (I) The percentage of TUNEL-positive neuromasts was calculated for each treatment and represented as mean +/− SEM. (J–R) Proliferation assays were performed in 5dpf Tg(brn3c:GFP) in the presence/absence of Qx and the corresponding ototoxin, by the BrdU-labelling method (red). Animals were immunostained for GFP (green). (J) control. (K) Neo 200 µM 30 min. (L) GM 50 µM 1 hour. (M) CP: 400 µM 2 hours. (N) Qx 300 µM 8 hours. (O) Qx 300 µM 8 hours + Neo 200 µM 30 min. (P) Qx 300 µM 8 hours + GM 50 µM 1 hour. (Q) Qx 300 µM 8 hours + CP 400 µM 2 hours. Asterisks denote neuromast supporting cells positive for BrdU. (R) The percentage of BrdU-positive supporting cells per neuromast was calculated for each treatment and represented as mean +/− SEM. One-way ANOVA, *p < 0.05, **p < 0.01. Black asterisks compared versus corresponding control. Red asterisk compared versus the corresponding ototoxin-only treatment. Scale bar: (A–H) 10 µm, (J–O) 7 μm. Data were taken from at least 15 animals and 3 experiments runs.