Dai Xufeng, Zhang Hua, Han Juanjuan, He Ying, Zhang Yangyang, Qi Yan, Pang Ji-Jing
School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China.
PLoS One. 2016 May 26;11(5):e0156542. doi: 10.1371/journal.pone.0156542. eCollection 2016.
Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is necessary for photoreceptors to generate an important lipid component of their membranes. The absence of LPCAT1 results in early and rapid rod and cone degeneration. Retinal degeneration 11 (rd11) mice carry a mutation in the Lpcat1 gene, and are an excellent model of early-onset rapid retinal degeneration (RD). To date, no reports have documented gene therapy administration in the rd11 mouse model at different ages. In this study, the AAV8 (Y733F)-smCBA-Lpcat1 vector was subretinally injected at postnatal day (P) 10, 14, 18, or 22. Four months after injection, immunohistochemistry and analysis of retinal morphology showed that treatment at P10 rescued about 82% of the wild-type retinal thickness. However, the diffusion of the vector and the resulting rescue were limited to an area around the injection site that was only 31% of the total retinal area. Injection at P14 resulted in vector diffusion that covered approximately 84% of the retina, and we found that gene therapy was more effective against RD when exposure to light was limited before and after treatment. We observed long-term preservation of electroretinogram (ERG) responses, and preservation of retinal structure, indicating that early treatment followed by limited light exposure can improve gene therapy effectiveness for the eyes of rd11 mice. Importantly, delayed treatment still partially preserved M-cones, but not S-cones, and M-cones in the rd11 retina appeared to have a longer window of opportunity for effective preservation with gene therapy. These results provide important information regarding the effects of subretinal gene therapy in the mouse model of LPCAT1-deficiency.
溶血磷脂酰胆碱酰基转移酶1(LPCAT1)是光感受器生成其细胞膜重要脂质成分所必需的。LPCAT1缺失会导致视杆和视锥细胞早期快速退化。视网膜退化11(rd11)小鼠的Lpcat1基因发生突变,是早发性快速视网膜退化(RD)的优秀模型。迄今为止,尚无报道记录在不同年龄的rd11小鼠模型中进行基因治疗给药的情况。在本研究中,在出生后第10、14、18或22天对AAV8(Y733F)-smCBA-Lpcat1载体进行视网膜下注射。注射后四个月,免疫组织化学和视网膜形态分析表明,在出生后第10天进行治疗可挽救约82%的野生型视网膜厚度。然而,载体的扩散以及由此产生的挽救作用仅限于注射部位周围的区域,该区域仅占视网膜总面积的31%。在出生后第14天注射导致载体扩散覆盖了约84%的视网膜,并且我们发现,当治疗前后限制光照时,基因治疗对RD更有效。我们观察到视网膜电图(ERG)反应的长期保存以及视网膜结构的保存,这表明早期治疗后限制光照可以提高基因治疗对rd11小鼠眼睛的有效性。重要的是,延迟治疗仍能部分保留M型视锥细胞,但不能保留S型视锥细胞,并且rd11视网膜中的M型视锥细胞似乎有更长的机会窗口通过基因治疗实现有效保存。这些结果提供了关于视网膜下基因治疗在LPCAT1缺陷小鼠模型中的作用的重要信息。