Fondazione per la Ricerca Biomedica Avanzata, Istituto Veneto di Medicina Molecolare, Padova, Italy.
PLoS One. 2011;6(8):e23279. doi: 10.1371/journal.pone.0023279. Epub 2011 Aug 18.
The deafness locus DFNB1 contains GJB2, the gene encoding connexin26 and GJB6, encoding connexin30, which appear to be coordinately regulated in the inner ear. In this work, we investigated the expression and function of connexin26 and connexin30 from postnatal day 5 to adult age in double transgenic Cx26(Sox10Cre) mice, which we obtained by crossing connexin26 floxed mice with a deleter Sox10-Cre line. Cx26(Sox10Cre) mice presented with complete connexin26 ablation in the epithelial gap junction network of the cochlea, whereas connexin30 expression was developmentally delayed; immunolabeling patterns for both connexins were normal in the cochlear lateral wall. In vivo electrophysiological measurements in Cx26(Sox10Cre) mice revealed profound hearing loss accompanied by reduction of endocochlear potential, and functional experiments performed in postnatal cochlear organotypic cultures showed impaired gap junction coupling. Transduction of these cultures with a bovine adeno associated virus vector restored connexin26 protein expression and rescued gap junction coupling. These results suggest that restoration of normal connexin levels by gene delivery via recombinant adeno associated virus could be a way to rescue hearing function in DFNB1 mouse models and, in future, lead to the development of therapeutic interventions in humans.
耳聋基因 DFNB1 包含编码连接蛋白 26（connexin26）的 GJB2 和编码连接蛋白 30（connexin30）的 GJB6，它们似乎在内耳中协同调节。在这项工作中，我们研究了双转基因 Cx26（Sox10Cre）小鼠从出生后第 5 天到成年期的 connexin26 和 connexin30 的表达和功能，我们通过将 connexin26 基因敲除小鼠与一个缺失型 Sox10-Cre 系杂交获得了这些小鼠。Cx26（Sox10Cre）小鼠的耳蜗上皮细胞间隙连接网络中完全缺失了 connexin26，而 connexin30 的表达则发育延迟；两种连接蛋白的免疫标记模式在耳蜗侧墙上均正常。在 Cx26（Sox10Cre）小鼠体内的电生理测量显示，听力严重受损，同时内淋巴电位降低，在出生后耳蜗器官型培养中的功能实验显示缝隙连接偶联受损。用牛腺相关病毒载体转导这些培养物可恢复 connexin26 蛋白表达并挽救缝隙连接偶联。这些结果表明，通过重组腺相关病毒载体进行基因传递来恢复正常的连接蛋白水平可能是拯救 DFNB1 小鼠模型听力功能的一种方法，并在未来导致人类治疗干预的发展。
