Lin Joshua S, Nguyen Nhi V, Shibata Seiji B
Caruso Department of Otolaryngology - Head and Neck Surgery, University of Southern California, Los Angeles, California, USA.
Neuroreport. 2025 Jun 4;36(9):497-503. doi: 10.1097/WNR.0000000000002172. Epub 2025 May 14.
In-situ neuronal reprogramming in the cochlea through gene therapy offers an avenue to restore hearing loss caused by neuronal damage. One possible source of neuronal conversion is the nonspiral ganglion cells (NSGCs), which include satellite cells, Schwann cells, and otic mesenchyme cells. A major obstacle for this approach is the vector-mediated transgene delivery toward NSGCs. Herein, we sought to assess the transduction profile of adeno-associated virus (AAV) serotypes with peripheral glial cell tropism in the murine inner ear. AAV-1, AAV-DJ, and AAV-PHP.eB with a cytomegalovirus promoter-driven enhanced green flourescent protein (eGFP) reporter were injected into CBA/CaJ neonatal mice via the posterior semicircular canal. One week postinjection, the cochlear tissue was collected for immunohistochemistry in whole-mount and mid-modiolar sections to assess the colocalization of eGFP within the NSGCs in the osseous spiral lamina and Rosenthal's canal. The contralateral ear served as an internal control. Auditory brain responses (ABRs) were recorded 30 days postinjection to assess for hearing loss. AAV-1 and AAV-DJ demonstrated 30-32% transduction efficacy of Pou3f4 immunopositive otic mesenchyme cells, whereas transduction efficacy of Sox2 or Sox10 positive Schwann cells and satellite cells was 0.8-1.82% for all serotypes. At 30 days postinjection, ABR thresholds in the injected mice were comparable to those of the noninjected control. We were able to transduce otic mesenchyme cells among SGNCs in the spiral ganglion region, whereas transduction of Schwann cells and satellite cells continues to pose challenges with AAV-1, AAV-DJ, and AAV-PHP.eB serotypes.
通过基因疗法在耳蜗中进行原位神经元重编程为恢复由神经元损伤引起的听力损失提供了一条途径。神经元转化的一个可能来源是非螺旋神经节细胞（NSGCs），其中包括卫星细胞、施万细胞和耳间质细胞。这种方法的一个主要障碍是载体介导的转基因向NSGCs的递送。在此，我们试图评估具有外周神经胶质细胞嗜性的腺相关病毒（AAV）血清型在小鼠内耳中的转导情况。将携带巨细胞病毒启动子驱动的增强型绿色荧光蛋白（eGFP）报告基因的AAV-1、AAV-DJ和AAV-PHP.eB通过后半规管注射到CBA/CaJ新生小鼠体内。注射后一周，收集耳蜗组织进行全层和中膜切片的免疫组织化学分析，以评估eGFP在骨螺旋板和罗森塔尔管中NSGCs内的共定位情况。对侧耳作为内部对照。在注射后30天记录听觉脑干反应（ABR）以评估听力损失情况。AAV-1和AAV-DJ对Pou3f4免疫阳性的耳间质细胞的转导效率为30 - 32%，而对于所有血清型，Sox2或Sox10阳性的施万细胞和卫星细胞的转导效率为0.8 - 1.82%。在注射后30天，注射小鼠的ABR阈值与未注射对照的阈值相当。我们能够转导螺旋神经节区域SGNCs中的耳间质细胞，而对于AAV-1、AAV-DJ和AAV-PHP.eB血清型，施万细胞和卫星细胞的转导仍然存在挑战。
