Figure 2
5-aza injection stimulates the generation of new HCs in a deafened mouse model. (a) Cochlear and organ of Corti (OC) images show expression of the hair cell protein Myosin VIIa (Myo7a) in the normal hearing mouse (arrow for IHC and arrowheads for OHCs), but not in saline-treated deafened mouse cochlea (arrow and arrowhead indicate IHC and OHC area respectively, without expression of HC protein Myosin VIIa). Two weeks post 5-aza injection into deafened mouse cochleae, cells express Myosin VIIa in the OC (arrows for IHCs and arrowheads for OHCs), suggesting new HC generation. Scale bar: 50 µm in cochlear section overview; 20 µm in OC highlight. (b) Basilar membrane surface preparations were obtained from mice two weeks after 5-aza or saline injection. Apical turn basilar membrane surface preparation shows Myosin VIIa-expressing HCs in normal hearing inner ear, but not in saline-treated deafened mouse inner ear. However, new HCs are found in 5-aza-treated deafened mouse inner ear. Arrows indicate the IHC area, whereas arrowheads suggest the OHC area. Scale bar: 20 µm. (c) Quantification of HCs in different cochlear turns in basilar membrane surface preparation two weeks after 5-aza or saline injection into deafened mice. One-way ANOVA was performed to compare the difference among the three groups, which showed a significant difference in all three cochlear turns (P < 0.01).
