Deng Wen-Tao, Brothers Brooke, Sechrest Emily, Ma Li, Ashcraft Madyson, Guan Tongju, Barbera Robert, Cahill Marion, Shaw Lee, Chen Becky, Baehr Wolfgang, Hu Gangqing, Stoilov Peter
West Virginia University.
West Vriginia University.
Res Sq. 2025 Apr 7:rs.3.rs-6075007. doi: 10.21203/rs.3.rs-6075007/v1.
Blue cone monochromacy (BCM) is an X-linked retinal disorder caused by mutations in the /OPN1MW gene locus, resulting in impaired cone function and structural degeneration. We conducted a comparative analysis of AAV-mediated gene therapy in double knockout (DKO) and / (C198R) BCM mouse models and evaluated the therapeutic window, efficacy, and longevity. Our results demonstrate that the AAV8-Y733F capsid achieved superior cone rescue compared to AAV5. While both DKO and C198R models showed similar therapeutic windows and rescue longevity, treatment efficacy decreased markedly in older mutant mice. Structural analysis revealed that aged cones in both models displayed degenerative changes, including mislocalized mitochondria and compromised connecting cilia. At the molecular level, we observed reduced AAV-mediated transgene expression in DKO and C198R older cones, which may result from decreased transduction efficiency, decreased circular episome stability, genome-wide transcription/translation downregulation, targeted mRNA/protein degradation, or overall cone degeneration. Notably, the cone-specific promoters for and maintained robust activity in degenerating cones. These findings suggest that combining an efficient AAV serotype with an optimized cone promoter could be a viable approach to extend the therapeutic window and enhance treatment longevity for BCM patients.
蓝锥单色视（BCM）是一种由/OPN1MW基因座突变引起的X连锁视网膜疾病，导致视锥功能受损和结构退化。我们在双敲除（DKO）和/（C198R）BCM小鼠模型中对腺相关病毒（AAV）介导的基因治疗进行了比较分析，并评估了治疗窗口、疗效和持久性。我们的结果表明，与AAV5相比，AAV8-Y733F衣壳在拯救视锥方面表现更优。虽然DKO和C198R模型显示出相似的治疗窗口和拯救持久性，但在年龄较大的突变小鼠中治疗效果明显下降。结构分析显示，两种模型中衰老的视锥都出现了退行性变化，包括线粒体定位错误和连接纤毛受损。在分子水平上，我们观察到在DKO和C198R衰老视锥中AAV介导的转基因表达降低，这可能是由于转导效率降低、环状附加体稳定性下降、全基因组转录/翻译下调、靶向mRNA/蛋白质降解或视锥整体退化所致。值得注意的是，和的视锥特异性启动子在退化的视锥中保持了强大的活性。这些发现表明，将高效的AAV血清型与优化的视锥启动子相结合可能是一种可行的方法，以扩大BCM患者的治疗窗口并提高治疗持久性。
