Reduced Phenotypic Severity Following Adeno-Associated Virus-Mediated Fmr1 Gene Delivery in Fragile X Mice
Reduced Phenotypic Severity Following Adeno-Associated Virus-Mediated Fmr1 Gene Delivery in Fragile X Mice
复制标题
DOI：
10.1038/npp.2014.167
复制
发表时间：
2014-12-01
影响因子：
7.6
通讯作者：
Hampson, David R.
中科院分区：
文献类型：
--
作者：
Gholizadeh, Shervin;Arsenault, Jason;Hampson, David R.
脆性X综合征（FXS）是由编码脆性X智力低下蛋白（FMRP）的FMR 1基因中的三核苷酸重复扩增引起的神经发育障碍。为了确定中枢神经系统中的FMRP表达是否可以逆转FXS的Fmr 1敲除（KO）小鼠模型中的表型缺陷，我们使用了具有来自血清型9的病毒衣壳的单链腺相关病毒（AV）载体，其中包含FMRP的主要亚型。FMRP转基因表达由神经元选择性突触蛋白-1启动子驱动。通过单次双侧脑室内注射将载体递送至新生Fmr 1 KO小鼠的脑中，并在注射后22-26或50-56天进行转基因表达和行为评估。免疫印迹和免疫细胞化学分析的AAV FMRP注射小鼠显示FMRP的表达在纹状体，海马，压后皮质，扣带皮质。细胞表达对神经元具有选择性，并且在注射后56天在海马和皮质中达到与野生型水平的50%相似。在注射磷酸盐缓冲盐水的Fmr 1 KO小鼠中观察到的病理性升高的重复行为和社会支配行为的缺陷在注射AAV FMRP的小鼠中被逆转。这些结果提供了基因治疗可以纠正FXS小鼠模型中特定行为异常的原理的第一个证据。
Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by a trinucleotide repeat expansion in the FMR1 gene that codes for fragile X mental retardation protein (FMRP). To determine if FMRP expression in the central nervous system could reverse phenotypic deficits in the Fmr1 knockout (KO) mouse model of FXS, we used a single-stranded adeno-associated viral (AAV) vector with viral capsids from serotype 9 that contained a major isoform of FMRP. FMRP transgene expression was driven by the neuron-selective synapsin-1 promoter. The vector was delivered to the brain via a single bilateral intra,cerebroventricular injection into neonatal Fmr1 KO mice and transgene expression and behavioral assessments were conducted 22-26 or 50-56 days post injection. Western blotting and immunocytochemical analyses of AAV FMRP-injected mice revealed FMRP expression in the striatum, hippocampus, retrosplenial cortex, and cingulate cortex. Cellular expression was selective for neurons and reached similar to 50% of wild-type levels in the hippocampus and cortex at 56 days post injection. The pathologically elevated repetitive behavior and the deficit in social dominance behavior seen in phosphate-buffered saline-injected Fmr1 KO mice were reversed in AAV FMRP-injected mice. These results provide the first proof of principle that gene therapy can correct specific behavioral abnormalities in the mouse model of FXS.