Modeling Rett Syndrome Using TALEN-Edited MECP2 Mutant Cynomolgus Monkeys

Gene-editing technologies have made it feasible to create nonhuman primate models for human genetic disorders. Here, we report detailed genotypes and phenotypes of TALEN-edited MECP2 mutant cynomolgus monkeys serving as a model for a neurodevelopmental disorder, Rett syndrome (RTT), which is caused by loss-of-function mutations in the human MECP2 gene. Male mutant monkeys were embryonic lethal, reiterating that RTT is a disease of females. Through a battery of behavioral analyses, including primate-unique eye-tracking tests, in combination with brain imaging via MRI, we found a series of physiological, behavioral, and structural abnormalities resembling clinical manifestations of RTT. Moreover, blood transcriptome profiling revealed that mutant monkeys resembled RTT patients in immune gene dysregulation. Taken together, the stark similarity in phenotype and/or endophenotype between monkeys and patients suggested that gene-edited RTT founder monkeys would be of value for disease mechanistic studies as well as development of potential therapeutic interventions for RTT

Efficient Modulation of Exon Skipping via Antisense Circular RNAs

Splice-switching antisense oligonucleotides (ASOs) and engineered U7 small nuclear ribonucleoprotein (U7 Sm OPT) are the most commonly used methods for exon skipping. However, challenges remain, such as limited organ delivery and repeated dosing for ASOs and unknown risks of by-products produced by U7 Sm OPT. Here, we showed that antisense circular RNAs (AS-circRNAs) can effectively mediate exon skipping in both minigene and endogenous transcripts. We also showed a relatively higher exon skipping efficiency at the tested Dmd minigene than U7 Sm OPT. AS-circRNA specifically targets the precursor mRNA splicing without off-target effects. Moreover, AS-circRNAs with adeno-associated virus (AAV) delivery corrected the open reading frame and restored the dystrophin expression in a mouse model of Duchenne muscular dystrophy. In conclusion, we develop an alternative method for regulating RNA splicing, which might be served as a novel tool for genetic disease treatment

Modeling Rett Syndrome Using TALEN-Edited MECP2 Mutant Cynomolgus Monkeys

Gene-editing technologies have made it feasible to create nonhuman primate models for human genetic disorders. Here, we report detailed genotypes and phenotypes of TALEN-edited MECP2 mutant cynomolgus monkeys serving as a model for a neurodevelopmental disorder, Rett syndrome (RTT), which is caused by loss-of-function mutations in the human MECP2 gene. Male mutant monkeys were embryonic lethal, reiterating that RTT is a disease of females. Through a battery of behavioral analyses, including primate-unique eye-tracking tests, in combination with brain imaging via MRI, we found a series of physiological, behavioral, and structural abnormalities resembling clinical manifestations of RTT. Moreover, blood transcriptome profiling revealed that mutant monkeys resembled RTT patients in immune gene dysregulation. Taken together, the stark similarity in phenotype and/or endophenotype between monkeys and patients suggested that gene-edited RTT founder monkeys would be of value for disease mechanistic studies as well as development of potential therapeutic interventions for RTT.National Key Research and Development Program [2016YFA0101401, 2016YFA0100800]; National & Provincial Natural Science Foundation of China [U1602224, U1302227, 31571534, 2015FA037, 91319309, 31450110428, 31620103904, 2013HB133, 13JC1407102]; National Institute of Child Health Development of the NIH [U54HD087101-01]SCI(E)ARTICLE5945-+16