Zong Yan-Jun, Liu Xiao-Zhou, Shi Xin-Yu, Zhao Zheng-Dong, Sun Yu
Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Institute of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Theranostics. 2025 Apr 22;15(12):5801-5825. doi: 10.7150/thno.112225. eCollection 2025.
The gene, which encodes connexin 26 (Cx26), is recognized as the leading cause of non-syndromic hereditary hearing loss. In clinical settings, a total of 131 Cx26 mutations have been identified in association with hearing loss. Certain Cx26 mutants display normal structural and functional properties but fail to translocate to the plasma membrane. Enhancing the membrane localization of these mutants may provide a promising strategy for rescuing hearing loss and hair cell degeneration. This study investigated the membrane localization of Cx26 using cell lines, cultured cochlear explants, and murine models. Key proteins involved in the membrane localization of Cx26 were identified and validated through immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP). Additionally, cell lines and murine models harboring Cx26 mutants were developed to evaluate the effects of Narciclasine on enhancing the membrane localization of these mutants, as well as its potential to rescue hearing loss. The membrane localization of Cx26 was dependent on the integrity of the intracellular transport network consisting of microtubules, actin microfilaments, and the Golgi apparatus. Additionally, SPTBN1 played a significant role in this process. The transmembrane domain 4 (TM4) region exhibited a strong association with the membrane localization of Cx26, and Cx26 mutants located in TM4 region retained in the cytoplasm. Narciclasine promoted cytoskeletal development, thereby enhancing the membrane localization of Cx26 mutants retained in the cytoplasm. This process helped to reconstruct the inner ear gap junction network and rescue hearing loss and hair cell degeneration. These findings present that enhancing the membrane localization of Cx26 mutants can significantly improve auditory function. This strategy offers a potential therapeutic approach for addressing hereditary sensorineural hearing loss associated with mutations.
编码连接蛋白26（Cx26）的基因被认为是导致非综合征性遗传性听力损失的主要原因。在临床环境中，已鉴定出总共131种与听力损失相关的Cx26突变。某些Cx26突变体具有正常的结构和功能特性，但无法转运至质膜。增强这些突变体的膜定位可能为挽救听力损失和毛细胞退化提供一种有前景的策略。本研究使用细胞系、培养的耳蜗外植体和小鼠模型研究了Cx26的膜定位。通过免疫沉淀-质谱法（IP-MS）和免疫共沉淀（Co-IP）鉴定并验证了参与Cx26膜定位的关键蛋白。此外，构建了携带Cx26突变体的细胞系和小鼠模型，以评估水仙环素对增强这些突变体膜定位的作用及其挽救听力损失的潜力。Cx26的膜定位取决于由微管、肌动蛋白微丝和高尔基体组成的细胞内运输网络的完整性。此外，SPTBN1在此过程中发挥了重要作用。跨膜结构域4（TM4）区域与Cx26的膜定位表现出强烈关联，位于TM4区域的Cx26突变体保留在细胞质中。水仙环素促进细胞骨架发育，从而增强保留在细胞质中的Cx26突变体的膜定位。这一过程有助于重建内耳缝隙连接网络并挽救听力损失和毛细胞退化。这些发现表明，增强Cx26突变体的膜定位可显著改善听觉功能。该策略为解决与突变相关的遗传性感音神经性听力损失提供了一种潜在的治疗方法。
