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. Author manuscript; available in PMC: 2020 Sep 15.
Published in final edited form as: Dev Biol. 2019 Jun 8;453(2):191–205. doi: 10.1016/j.ydbio.2019.06.003

Fig. 8. The effects of inhibition of GSK3 can be partially rescued by BMP4.

Fig. 8.

A. qRT-PCR quantification of effects of CHIR or CHIR plus BMP4 on expression of Bmp4 and Fgf10 in cochlear explants. In CHIR-treated explants, Bmp4 is significantly decreased (p = 0.0012) while levels of Fgf10 are higher but variable (n.s., p = 0.22). In double-treated explants, Fgf10 is reduced relative to CHIR-treated (p = 0.012), but does not differ from controls (n.s., p = 0.29). B-D. Level of pSMAD1 in the sensory region of explants established on E13.5 and treated with DMSO, BMP4 (50 ng/ml) or CHIR (2 μM) for 4 DIV. Levels of pSMAD1 are higher in response to treatment with BMP4 (C) and lower in explants treated with CHIR (D). E. Quantification of average fluorescence intensity for pSMAD1 in cells for each of the three conditions in B-D. pSMAD1 intensity is significantly increased in response to BMP4 and significantly decreased in response to CHIR (N = 4 for each condition. DMSO vs. BMP4 explants, p = 0.0055. DMSO vs CHIR explants, p = 0.030). F–I. Surface views of the middle regions from explants established and maintained as described, stained for POU4F3. Treatment with BMP4 alone does not change the ratio of IHCs to OHCs. CHIR-treatment induces a significant change in the IHC/OHC ratio, but addition of BMP4 results in a partial rescue of the normal phenotype. J. Quantification of changes in the number of IHCs and OHCs under the conditions in F–I. Addition of BMP4 significantly reduces the CHIR-mediated increase in IHCs and significantly increases the number of OHCs. While IHCs are still significantly elevated in CHIR + BMP4-treated explants relative to control (p < 0.0001), OHCs are not significantly different between CHIR + BMP4 and control (p = 0.86). All IHCs comparisons are significant except DMSO vs. BMP4. No OHC comparisons differ except CHIR + BMP4 vs. DMSO or CHIR (p = 0.0004, 0.012). DMSO-treated explants N = 11, BMP4-treated explants N = 7. CHIR-treated explants N = 11. CHIR + BMP4 treated explants N = 10. Scale bars (B–D) = 25 μm. Scale bars (F–I) = 50 μm.