Abstract:
Leber congenital amaurosis (LCA) is the most common genetic cause of congenital visual impairment in infants and children. Patients with LCA who harbor RPE65 mutations exhibit a deficiency in photoreceptor rhodopsin, leading to severe night blindness and visual impairment following birth. Since either gene replacement therapy or anti-apoptosis therapy alone cannot maintain both functional and morphological normality for a long time in the animal model, we propose a robust treatment strategy, that is, gene replacement therapy combined with anti-apoptotic therapy to protect photoreceptors from further degeneration while compensating for lost RPE65 function. Here, rd12 mice were injected subretinally at postnatal day 14 with four vector administrations, respectively. At 6 months after treatment, it was discovered that injection of three vectors, AAV8 (Y733F)-CBA-hRPE65, AAV8(Y733F)-CBA-hRPE65-BCL-2-L10 and mixture of half-dose AAV8(Y733F)-CBA-hRPE65 and half-dose AAV8 (Y733F)-CBA-BCL-2-L10, could partially restore the visual function of rd12 mice. Meanwhile, these treated eyes also exhibited a thicker outer nuclear layer (ONL) structure. However, despite the fact that the eyes of rd12 mice injected with the AAV8 (Y733F)-CBA-BCL-2-L10 vector displayed a slightly thicker ONL structure compared to untreated eyes, the visual function of the treated eyes did not recover. Continuing the observation period to 12 months after treatment, we found that compared to rd12 mice at 6-month post-treatment, rd12 mice injected with AAV8 (Y733F)-CBA-hRPE65 or mixture of half-dose AAV8(Y733F)-CBA-hRPE65 and half-dose AAV8 (Y733F)-CBA-BCL-2-L10 exhibited varying degrees of decline in both visual function and ONL thickness. However, in the case of rd12 mice injected with the AAV8(Y733F)-CBA-hRPE65-BCL-2-L10 vector, the ONL thickness remains consistent at both 6 and 12 months after treatment. These mice continued to maintain a relatively strong visual function and showed restoration in the levels of RPE65 and Rhodopsin protein expression. Our findings illustrate that early postnatal treatment with AAV vectors containing both the hRPE65 gene and the Bcl-2L10 anti-apoptotic gene provide enhanced and sustained retinal protection.
摘要:
Leber先天性黑蒙(LCA)是婴儿和儿童先天性视力障碍的最常见遗传原因。携带RPE65突变的LCA患者表现出光感受器视紫红质缺乏,导致出生后严重夜盲症和视力障碍。由于基因替代疗法或抗凋亡疗法不能在动物模型中长时间维持功能和形态的正常。我们提出了一个强有力的治疗策略,也就是说,基因替代疗法与抗凋亡疗法相结合,以保护光感受器免受进一步变性,同时补偿失去的RPE65功能。这里,rd12小鼠在出生后第14天用四种载体给药进行视网膜下注射,分别。治疗后6个月,发现注射三种载体,AAV8(Y733F)-CBA-hRPE65,AAV8(Y733F)-CBA-hRPE65-BCL-2-L10以及半剂量AAV8(Y733F)-CBA-hRPE65和半剂量AAV8(Y733F)-CBA-BCL-2-L10的混合物,可以部分恢复r12小鼠的视觉功能。同时,这些治疗的眼睛也表现出较厚的外核层(ONL)结构。然而,尽管注射AAV8(Y733F)-CBA-BCL-2-L10载体的rd12小鼠的眼睛显示出比未治疗的眼睛稍厚的ONL结构,接受治疗的眼睛的视觉功能没有恢复。继续观察期至治疗后12个月,我们发现与治疗后6个月的rd12小鼠相比,注射AAV8(Y733F)-CBA-hRPE65或半剂量AAV8(Y733F)-CBA-hRPE65和半剂量AAV8(Y733F)-CBA-BCL-2-L10的混合物的rd12小鼠视觉功能和ONL厚度均表现出不同程度的下降。然而,在注射AAV8(Y733F)-CBA-hRPE65-BCL-2-L10载体的rd12小鼠的情况下,治疗后6个月和12个月的ONL厚度保持一致.这些小鼠继续保持相对强的视觉功能,并显示RPE65和视紫红质蛋白表达水平的恢复。我们的发现表明,使用含有hRPE65基因和Bcl-2L10抗凋亡基因的AAV载体进行出生后早期治疗可提供增强和持续的视网膜保护。