Progress in gene editing research has been accelerated by utilizing engineered nucleases in combination with induced pluripotent stem cell (iPSC) technology. Here, we report transcription activator-like effector nuclease (TALEN)-mediated reincorporation of Arg1 exons 7 and 8 in iPSCs derived from arginase-1-deficient mice possessing Arg1^Δ alleles lacking these terminal exons. The edited cells could be induced to differentiate into hepatocyte-like cells (iHLCs) in vitro and were subsequently used for transplantation into our previously described (Sin et al., PLoS ONE 2013) tamoxifen-inducible Arg1-Cre arginase-1-deficient mouse model. While successful gene-targeted repair was achieved in iPSCs containing Arg1^Δ alleles, only minimal restoration of urea cycle function could be observed in the iHLC-transplanted mice compared to control mice, and survival in this lethal model was extended by up to a week in some mice. The partially rescued phenotype may be due to inadequate regenerative capacity of arginase-1-expressing cells in the correct metabolic zones. Technical hurdles exist and will need to be overcome for gene-edited iPSC to iHLC rescue of arginase-1 deficiency, a rare urea cycle disorder.

通过将工程核酸酶与诱导多能干细胞（iPSC）技术结合使用，可以加快基因编辑研究的进展。这里，我们报告类转录活化因子核酸酶（TALEN）的介导重新纳入ARG1在具有从精氨酸酶1缺陷小鼠的外显子的iPSC 7和8 ARG1 ^Δ缺乏这些终端的外显子的等位基因。可以将编辑后的细胞在体外诱导分化为肝细胞样细胞（iHLCs），随后将其移植到我们先前描述的（Sin等人，PLoS ONE 2013）他莫昔芬诱导的Arg1-Cre精氨酸酶-1缺陷小鼠中模型。虽然在包含Arg1的iPSC中成功实现了针对基因的修复^Δ等位基因，与对照小鼠相比，在iHLC移植的小鼠中只能观察到尿素循环功能的最小恢复，并且在这种致死模型中，某些小鼠的存活期延长了长达一周。部分拯救的表型可能是由于在正确的代谢区内表达精氨酸酶1的细胞的再生能力不足所致。存在技术上的障碍，对于基因编辑的iPSC到iHLC挽救精氨酸酶-1缺乏症（一种罕见的尿素循环失调），需要克服这些技术障碍。