CRISPR-Cpf1 correction of muscular dystrophy mutations in human cardiomyocytes and mice
TL;DR: These findings are the first to show the efficiency of Cpf1-mediated correction of genetic mutations in human cells and an animal disease model and represent a significant step toward therapeutic translation of gene editing for correction of DMD.
Abstract: Duchenne muscular dystrophy (DMD), caused by mutations in the X-linked dystrophin gene (DMD), is characterized by fatal degeneration of striated muscles. Dilated cardiomyopathy is one of the most common lethal features of the disease. We deployed Cpf1, a unique class 2 CRISPR (clustered regularly interspaced short palindromic repeats) effector, to correct DMD mutations in patient-derived induced pluripotent stem cells (iPSCs) and mdx mice, an animal model of DMD. Cpf1-mediated genomic editing of human iPSCs, either by skipping of an out-of-frame DMD exon or by correcting a nonsense mutation, restored dystrophin expression after differentiation to cardiomyocytes and enhanced contractile function. Similarly, pathophysiological hallmarks of muscular dystrophy were corrected in mdx mice following Cpf1-mediated germline editing. These findings are the first to show the efficiency of Cpf1-mediated correction of genetic mutations in human cells and an animal disease model and represent a significant step toward therapeutic translation of gene editing for correction of DMD.
Citations
More filters
TL;DR: The basic mechanisms that set the CRISPR-Cas toolkit apart from other programmable gene-editing technologies are described, highlighting the diverse and naturally evolved systems now functionalized as biotechnologies.
Abstract: The diversity, modularity, and efficacy of CRISPR-Cas systems are driving a biotechnological revolution. RNA-guided Cas enzymes have been adopted as tools to manipulate the genomes of cultured cells, animals, and plants, accelerating the pace of fundamental research and enabling clinical and agricultural breakthroughs. We describe the basic mechanisms that set the CRISPR-Cas toolkit apart from other programmable gene-editing technologies, highlighting the diverse and naturally evolved systems now functionalized as biotechnologies. We discuss the rapidly evolving landscape of CRISPR-Cas applications, from gene editing to transcriptional regulation, imaging, and diagnostics. Continuing functional dissection and an expanding landscape of applications position CRISPR-Cas tools at the cutting edge of nucleic acid manipulation that is rewriting biology.
888 citations
01 Jan 2014
305 citations
TL;DR: Advances in therapeutic approaches for cardiac repair and regeneration are discussed, including cell-based therapies as well as the use of secretory factors, such as microRNAs and exosomes, direct reprogramming strategies, and gene editing to control cardiac remodelling and redirect the adult heart to a regenerative state, and the future prospects of preclinical and clinical trials of heart regeneration.
Abstract: Ischaemic heart disease is a leading cause of death worldwide. Injury to the heart is followed by loss of the damaged cardiomyocytes, which are replaced with fibrotic scar tissue. Depletion of cardiomyocytes results in decreased cardiac contraction, which leads to pathological cardiac dilatation, additional cardiomyocyte loss, and mechanical dysfunction, culminating in heart failure. This sequential reaction is defined as cardiac remodelling. Many therapies have focused on preventing the progressive process of cardiac remodelling to heart failure. However, after patients have developed end-stage heart failure, intervention is limited to heart transplantation. One of the main reasons for the dramatic injurious effect of cardiomyocyte loss is that the adult human heart has minimal regenerative capacity. In the past 2 decades, several strategies to repair the injured heart and improve heart function have been pursued, including cellular and noncellular therapies. In this Review, we discuss current therapeutic approaches for cardiac repair and regeneration, describing outcomes, limitations, and future prospects of preclinical and clinical trials of heart regeneration. Substantial progress has been made towards understanding the cellular and molecular mechanisms regulating heart regeneration, offering the potential to control cardiac remodelling and redirect the adult heart to a regenerative state.
233 citations
TL;DR: It is concluded that abolishing conserved RNA splicing acceptor/donor sites and directing the splicing machinery to skip mutant or out-of-frame exons through myoediting allow correction of the cardiac abnormalities associated with DMD by eliminating the underlying genetic basis of the disease.
Abstract: Genome editing with CRISPR/Cas9 is a promising new approach for correcting or mitigating disease-causing mutations. Duchenne muscular dystrophy (DMD) is associated with lethal degeneration of cardiac and skeletal muscle caused by more than 3000 different mutations in the X-linked dystrophin gene (DMD). Most of these mutations are clustered in “hotspots.” There is a fortuitous correspondence between the eukaryotic splice acceptor and splice donor sequences and the protospacer adjacent motif sequences that govern prokaryotic CRISPR/Cas9 target gene recognition and cleavage. Taking advantage of this correspondence, we screened for optimal guide RNAs capable of introducing insertion/deletion (indel) mutations by nonhomologous end joining that abolish conserved RNA splice sites in 12 exons that potentially allow skipping of the most common mutant or out-of-frame DMD exons within or nearby mutational hotspots. We refer to the correction of DMD mutations by exon skipping as myoediting. In proof-of-concept studies, we performed myoediting in representative induced pluripotent stem cells from multiple patients with large deletions, point mutations, or duplications within the DMD gene and efficiently restored dystrophin protein expression in derivative cardiomyocytes. In three-dimensional engineered heart muscle (EHM), myoediting of DMD mutations restored dystrophin expression and the corresponding mechanical force of contraction. Correcting only a subset of cardiomyocytes (30 to 50%) was sufficient to rescue the mutant EHM phenotype to near-normal control levels. We conclude that abolishing conserved RNA splicing acceptor/donor sites and directing the splicing machinery to skip mutant or out-of-frame exons through myoediting allow correction of the cardiac abnormalities associated with DMD by eliminating the underlying genetic basis of the disease.
192 citations
Cites methods from "CRISPR-Cpf1 correction of muscular ..."
...Immunostaining iPSC-derived cardiomyocytes were fixed with acetone and subjected to immunostaining, as described previously (25)....
[...]
...Cas9 and guide RNAs for correction or bypass of the mutations in iPSC lines were introduced into cells by nucleofection, as described previously (25)....
[...]
...Western blot analysis Western blot analysis for human iPSC–derived cardiomyocytes was performed, as described previously (25), using antibodies to dystrophin (ab15277, Abcam; D8168, Sigma-Aldrich), glyceraldehyde-3-phosphate dehydrogenase (MAB374, Millipore), and cardiac myosin heavy chain (ab50967, Abcam)....
[...]
...Pools of treated cells or single clones were then differentiated into induced cardiomyocytes (iCMs) using standardized conditions (25, 32)....
[...]
TL;DR: Single-cut correction of a dystrophin gene mutation with CRISPR/Cas9 restored dystophin expression in skeletal and cardiac muscles in a mouse model of Duchenne muscular dystrophy, suggesting that this strategy may have potential for efficiently correcting DMD mutations.
Abstract: Duchenne muscular dystrophy (DMD) is a severe, progressive muscle disease caused by mutations in the dystrophin gene. The majority of DMD mutations are deletions that prematurely terminate the dystrophin protein. Deletions of exon 50 of the dystrophin gene are among the most common single exon deletions causing DMD. Such mutations can be corrected by skipping exon 51, thereby restoring the dystrophin reading frame. Using clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9), we generated a DMD mouse model by deleting exon 50. These ΔEx50 mice displayed severe muscle dysfunction, which was corrected by systemic delivery of adeno-associated virus encoding CRISPR/Cas9 genome editing components. We optimized the method for dystrophin reading frame correction using a single guide RNA that created reframing mutations and allowed skipping of exon 51. In conjunction with muscle-specific expression of Cas9, this approach restored up to 90% of dystrophin protein expression throughout skeletal muscles and the heart of ΔEx50 mice. This method of permanently bypassing DMD mutations using a single cut in genomic DNA represents a step toward clinical correction of DMD mutations and potentially those of other neuromuscular disorders.
186 citations
Cites background from "CRISPR-Cpf1 correction of muscular ..."
...In addition, we have shown that the Cas9-related endonuclease Cpf1 can correct the Dmd mutation in mdx mice (20)....
[...]
References
More filters
TL;DR: This study’s findings can provide practical guidelines to steer partnership programs within the academic and clinical bodies, with the aim of providing a collaborative partnership approach to clinical education.
Abstract: The aim of our systematic review was to retrieve and integrate relevant evidence related to the process of formation and implementation of the academic–service partnership, with the aim of reformin...
41,134 citations
"CRISPR-Cpf1 correction of muscular ..." refers methods in this paper
...Immunohistochemistry of skeletal muscles, heart, and brain was performed, as previously described (7, 12), using a dystrophin antibody (MANDYS8, 1:800; Sigma-Aldrich)....
[...]
...net/ cas-offinder/), and off-target analysis was performed as previously described (12)....
[...]
TL;DR: This study reveals a family of endonucleases that use dual-RNAs for site-specific DNA cleavage and highlights the potential to exploit the system for RNA-programmable genome editing.
Abstract: Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems provide bacteria and archaea with adaptive immunity against viruses and plasmids by using CRISPR RNAs (crRNAs) to guide the silencing of invading nucleic acids. We show here that in a subset of these systems, the mature crRNA that is base-paired to trans-activating crRNA (tracrRNA) forms a two-RNA structure that directs the CRISPR-associated protein Cas9 to introduce double-stranded (ds) breaks in target DNA. At sites complementary to the crRNA-guide sequence, the Cas9 HNH nuclease domain cleaves the complementary strand, whereas the Cas9 RuvC-like domain cleaves the noncomplementary strand. The dual-tracrRNA:crRNA, when engineered as a single RNA chimera, also directs sequence-specific Cas9 dsDNA cleavage. Our study reveals a family of endonucleases that use dual-RNAs for site-specific DNA cleavage and highlights the potential to exploit the system for RNA-programmable genome editing.
12,865 citations
TL;DR: In this paper, the authors characterized Cpf1, a putative class 2 CRISPR effector, which is a single RNA-guided endonuclease lacking tracrRNA and utilizes a T-rich protospacer-adjacent motif.
3,436 citations
01 Apr 2015
TL;DR: In this paper, the RNA-guided endonuclease Cas9 has emerged as a versatile genome-editing platform and has been used for basic research and therapeutic applications that use the highly versatile adeno-associated virus (AAV) delivery vehicle.
Abstract: The RNA-guided endonuclease Cas9 has emerged as a versatile genome-editing platform. However, the size of the commonly used Cas9 from Streptococcus pyogenes (SpCas9) limits its utility for basic research and therapeutic applications that use the highly versatile adeno-associated virus (AAV) delivery vehicle. Here, we characterize six smaller Cas9 orthologues and show that Cas9 from Staphylococcus aureus (SaCas9) can edit the genome with efficiencies similar to those of SpCas9, while being more than 1 kilobase shorter. We packaged SaCas9 and its single guide RNA expression cassette into a single AAV vector and targeted the cholesterol regulatory gene Pcsk9 in the mouse liver. Within one week of injection, we observed >40% gene modification, accompanied by significant reductions in serum Pcsk9 and total cholesterol levels. We further assess the genome-wide targeting specificity of SaCas9 and SpCas9 using BLESS, and demonstrate that SaCas9-mediated in vivo genome editing has the potential to be efficient and specific.
1,826 citations
TL;DR: It is shown that CRISPR spacers derive from preexisting sequences, either chromosomal or within transmissible genetic elements such as bacteriophages and conjugative plasmids, implying a relationship betweenCRISPR and immunity against targeted DNA.
Abstract: Prokaryotes contain short DNA repeats known as CRISPR, recognizable by the regular spacing existing between the recurring units. They represent the most widely distributed family of repeats among prokaryotic genomes, suggesting a biological function. The origin of the intervening sequences, at present unknown, could provide clues about their biological activities. Here we show that CRISPR spacers derive from preexisting sequences, either chromosomal or within transmissible genetic elements such as bacteriophages and conjugative plasmids. Remarkably, these extrachromosomal elements fail to infect the specific spacer-carrier strain, implying a relationship between CRISPR and immunity against targeted DNA. Bacteriophages and conjugative plasmids are involved in prokaryotic population control, evolution, and pathogenicity. All these biological traits could be influenced by the presence of specific spacers. CRISPR loci can be visualized as mosaics of a repeated unit, separated by sequences at some time present elsewhere in the cell.
1,763 citations
"CRISPR-Cpf1 correction of muscular ..." refers background in this paper
...The CRISPR (clustered regularly interspaced short palindromic repeats) system functions as an adaptive immune system in bacteria and archaea that defends against phage infection (5)....
[...]