Figure 9.

EGF and the GSK3β inhibitor CHIR-99021 reverse the reinforcement of SC-SC junctions and promote proliferation of striolar SCs in utricles from adult mice. a, Low-magnification images illustrate that culture in EC medium for 11 d decreases the intensities of E-cadherin, β-catenin, and YAP immunostaining, but not N-cadherin immunostaining, in the striola of adult mouse utricles. Such decreases did not occur in the control medium. b, High-magnification images centered on the line of the polarity reversal (yellow dashes) depicting E-cadherin, N-cadherin β-catenin, and YAP immunostaining at the cellular level. c, The S/L ratios of E-cadherin, β-catenin, and YAP significantly decreased in adult mouse utricles cultured in EC medium compared with utricles cultured in control medium (n = 4 for Control and EC). The S/L ratio of N-cadherin did not differ significantly. d, Quantification of EdU⁺/Sox2⁺ cells revealed that culture in EC medium induced a 50-fold increase in the number of SCs that entered S-phase compared with the number of such SCs found in utricles cultured in control medium (n = 7 for Control and EC). e, As in P8 utricles, culture of adult mouse utricles in EC medium induced S-phase entry in striolar SCs. Data are mean ± SD. ns, Not significant (p ≥ 0.05). **p < 0.01, ***p < 0.001.