RESUMO
Severe congenital neutropenia (CN) is an inherited pre-leukemia bone marrow failure syndrome commonly caused by autosomal-dominant ELANE mutations (ELANE-CN). ELANE-CN patients are treated with daily injections of recombinant human granulocyte colony-stimulating factor (rhG-CSF). However, some patients do not respond to rhG-CSF, and approximately 15% of ELANE-CN patients develop myelodysplasia or acute myeloid leukemia. Here, we report the development of a curative therapy for ELANE-CN through inhibition of ELANE mRNA expression by introducing two single-strand DNA breaks at the opposing DNA strands of the ELANE promoter TATA box using CRISPR-Cas9D10A nickases-termed MILESTONE. This editing effectively restored defective neutrophil differentiation of ELANE-CN CD34+ hematopoietic stem and progenitor cells (HSPCs) in vitro and in vivo, without affecting the functions of the edited neutrophils. CRISPResso analysis of the edited ELANE-CN CD34+ HSPCs revealed on-target efficiencies of over 90%. Simultaneously, GUIDE-seq, CAST-Seq, and rhAmpSeq indicated a safe off-target profile with no off-target sites or chromosomal translocations. Taken together, ex vivo gene editing of ELANE-CN HSPCs using MILESTONE in the setting of autologous stem cell transplantation could be a universal, safe, and efficient gene therapy approach for ELANE-CN patients.
Assuntos
Sistemas CRISPR-Cas , Síndrome Congênita de Insuficiência da Medula Óssea , Edição de Genes , Terapia Genética , Elastase de Leucócito , Neutropenia , Regiões Promotoras Genéticas , Edição de Genes/métodos , Humanos , Neutropenia/congênito , Neutropenia/terapia , Neutropenia/genética , Terapia Genética/métodos , Síndrome Congênita de Insuficiência da Medula Óssea/terapia , Síndrome Congênita de Insuficiência da Medula Óssea/genética , Elastase de Leucócito/genética , Elastase de Leucócito/metabolismo , Animais , Camundongos , Neutrófilos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Mutação , Modelos Animais de Doenças , Fator Estimulador de Colônias de Granulócitos/genética , Doenças Genéticas Ligadas ao Cromossomo X/terapia , Doenças Genéticas Ligadas ao Cromossomo X/genéticaRESUMO
Non-coding RNA (ncRNAs) genes have attracted increasing attention in recent years due to their widespread involvement in physiological and pathological processes and regulatory networks. The study of the function and molecular partners of ncRNAs opens up opportunities for the early diagnosis and treatment of previously incurable diseases. However, the classical "loss-of-function" approach in ncRNA function analysis is challenged due to some specific issues. Here, we have studied the potency of two CRISPR/Cas9 variants, wild-type (SpCas9wt) and nickase (SpCas9D10A) programmable nucleases, for the editing of extended DNA sequences in human mesenchymal stromal cells (MSCs). Editing the genes of fibrosis-related hsa-miR-21-5p and hsa-miR-29c-3p, we have shown that a pair of SpCas9D10A molecules can effectively disrupt miRNA genes within the genomes of MSCs. This leads not only to a decrease in the level of knockout miRNA in MSCs and MSC-produced extracellular vesicles, but also to a change in cell physiology and the antifibrotic properties of the cell secretome. These changes correlate well with previously published data for the knockdown of certain miRNAs. The proposed approach can be used to knock out ncRNA genes within the genomes of MSCs or similar cell types in order to study their function in biological processes.