RESUMO
MECP2 duplication syndrome (MDS) is a neurodevelopmental disorder caused by tandem duplication of the MECP2 locus and its surrounding genes, including IRAK1. Current MDS mouse models involve transgenic expression of MECP2 only, limiting their applicability to the study of the disease. Herein, we show that an efficient and precise CRISPR/Cas9 fusion proximity-based approach can be utilized to generate an Irak1-Mecp2 tandem duplication mouse model ('Mecp2 Dup'). The Mecp2 Dup mouse model recapitulates the genomic landscape of human MDS by harboring a 160â kb tandem duplication encompassing Mecp2 and Irak1, representing the minimal disease-causing duplication, and the neighboring genes Opn1mw and Tex28. The Mecp2 Dup model exhibits neuro-behavioral abnormalities, and an abnormal immune response to infection not previously observed in other mouse models, possibly owing to Irak1 overexpression. The Mecp2 Dup model thus provides a tool to investigate MDS disease mechanisms and develop potential therapies applicable to patients.
Assuntos
Modelos Animais de Doenças , Duplicação Gênica , Quinases Associadas a Receptores de Interleucina-1 , Deficiência Intelectual Ligada ao Cromossomo X , Proteína 2 de Ligação a Metil-CpG , Animais , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , Quinases Associadas a Receptores de Interleucina-1/genética , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Deficiência Intelectual Ligada ao Cromossomo X/genética , Deficiência Intelectual Ligada ao Cromossomo X/patologia , Humanos , Camundongos Endogâmicos C57BL , Camundongos , Sistemas CRISPR-Cas/genética , Comportamento Animal , MasculinoRESUMO
Tandem duplication mutations are increasingly found to be the direct cause of many rare heritable diseases, accounting for up to 10% of cases. Unfortunately, animal models recapitulating such mutations are scarce, limiting our ability to study them and develop genome editing therapies. Here, we describe the generation of a novel duplication mouse model, harboring a multi-exonic tandem duplication in the Dmd gene which recapitulates a human mutation. Duplication correction of this mouse was achieved by implementing a single-guide RNA (sgRNA) CRISPR/Cas9 approach. This strategy precisely removed a duplication mutation in vivo, restored full-length dystrophin expression, and was accompanied by improvements in both histopathological and clinical phenotypes. We conclude that CRISPR/Cas9 represents a powerful tool to accurately model and treat tandem duplication mutations. Our findings will open new avenues of research for exploring the study and therapeutics of duplication disorders.