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. 2016 Feb 23;6:21973. doi: 10.1038/srep21973

Figure 1. OHC loss in WT exceeds that in prestin-KO mice after HPβCD treatment.

Figure 1

(a,b) WT and prestin-KO mice from a het x het breeder pair on the FVB background were treated with either saline or 8000 mg/kg HPβCD at P20–21. OHC survival was determined 7 days post injection. Thin lines represent the results from individual animals while thick lines are the average of each treatment (WT saline, n = 2; WT HPβCD n = 3; KO saline, n = 3; HPβCD, n = 3). OHC loss in the mid-to-basal region is observed in all WT cochleae, while OHCs were better preserved in KO cochleae. The dashed line indicates the boundary between apex and mid-base used in (c–e). (c) OHC survival is significant in mid-to-basal regions of HPβCD-treated prestin-KO cochlea. Mean ± SD are plotted, and significance determined using one-way ANOVA with Tukey’s post analysis. n.s., not significant; ***p ≤ 0.001. (d,e) Representative images of saline or HPβCD-treated cochleae from WT (d) and prestin-KO (e) animals at apex and mid-base. Anti-oncomodulin (OCM) antibody was used to stain OHCs, and phalloidin-Alexa 546 for actin. Scale bars, 100 μm. (f,g) WT mice on the FVB background were treated with 8000 mg/kg HPβCD at P21 for 8 hours, and their cochleae harvested for immunofluorescence. The whole mount OC sections were stained with anti-prestin (WT) or anti-oncomodulin (KO) antibodies, Phalloidin-Alexa 546, and Hoechst 33342 for OHCs, actin, and nuclei, respectively. (f) Representative images of HPβCD-treated cochleae from WT (top panels) and prestin-KO (bottom panels) at the apex. Early events of OHC loss were observed for both WT and KO. For WT, fragmented OHCs were seen (judged by smooth vs. punctate prestin staining). For prestin-KO, absence of OCM staining indicates OHC loss. (g) Representative images of HPβCD-treated cochleae from prestin-WT and KO at the mid-base region of the cochlea. No intact OHCs were present in WT (left panels), although condensed nuclei indicating dying cells were observed. OHCs are largely intact in KO mice (right panels). Scale bars, 20 μm.