Highly efficient prime editing by introducing same-sense mutations in pegRNA or stabilizing its structure.
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE197730 | GEO | 2022/03/10
REPOSITORIES: GEO
Similar Datasets
Project description:Prime editor (PE), which is developed by combining Cas9 nickase and an engineered reverse transcriptase, can mediate all twelve types of base substitutions and small insertions or deletions in living cells but its efficiency remains low. Here, we develop spegRNA by introducing same-sense mutations at proper positions in the reverse-transcription template of pegRNA to increase PE's base-editing efficiency up-to 4,976-fold (on-average 353-fold). We also develop apegRNA by altering the pegRNA secondary structure to increase PE's indel-editing efficiency up-to 10.6-fold (on-average 2.77-fold). The spegRNA and apegRNA can be combined to further enhance editing efficiency. When spegRNA and apegRNA are used in PE3 and PE5 systems, the efficiencies of sPE3, aPE3, sPE5 and aPE5 systems are all enhanced significantly. The strategies developed in this study realize highly efficient prime editing at certain previously uneditable sites.
| S-EPMC8964725 | biostudies-literature
Project description:Highly efficient prime editing by introducing same-sense mutations in pegRNA or stabilizing its structure.
| PRJNA811688 | ENA
Project description:Prime editing is a powerful means of introducing precise changes to specific locations in mammalian genomes. However, the widely varying efficiency of prime editing across target sites of interest has limited its adoption in the context of both basic research and clinical settings. Here, we set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing efficiency. Utilizing a newly developed and highly sensitive method for mapping the genomic locations of a randomly integrated “sensor”, we identify specific epigenetic features that strongly correlate with the highly variable efficiency of prime editing across different genomic locations. Next, to assess the interaction of trans-acting factors with the cis-chromatin environment, we develop and apply a pooled genetic screening approach with which the impact of knocking down various DNA repair factors on prime editing efficiency can be stratified by cis-chromatin context. Finally, we demonstrate that we can dramatically modulate the efficiency of prime editing through epigenome editing, i.e. enhancing (or restricting) local chromatin accessibility in order to increase (or decrease) the efficiency of prime editing at a target site. Looking forward, we envision that the insights and tools described here will broaden the range of both basic research and therapeutic contexts in which prime editing is useful.
2023-04-12 | GSE228463 | GEO
Project description:Prime editing is a powerful means of introducing precise changes to specific locations in mammalian genomes. However, the widely varying efficiency of prime editing across target sites of interest has limited its adoption in the context of both basic research and clinical settings. Here, we set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing efficiency. Utilizing a newly developed and highly sensitive method for mapping the genomic locations of a randomly integrated “sensor”, we identify specific epigenetic features that strongly correlate with the highly variable efficiency of prime editing across different genomic locations. Next, to assess the interaction of trans-acting factors with the cis-chromatin environment, we develop and apply a pooled genetic screening approach with which the impact of knocking down various DNA repair factors on prime editing efficiency can be stratified by cis-chromatin context. Finally, we demonstrate that we can dramatically modulate the efficiency of prime editing through epigenome editing, i.e. enhancing (or restricting) local chromatin accessibility in order to increase (or decrease) the efficiency of prime editing at a target site. Looking forward, we envision that the insights and tools described here will broaden the range of both basic research and therapeutic contexts in which prime editing is useful.
2023-04-12 | GSE228464 | GEO
Project description:Prime editing is a powerful means of introducing precise changes to specific locations in mammalian genomes. However, the widely varying efficiency of prime editing across target sites of interest has limited its adoption in the context of both basic research and clinical settings. Here, we set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing efficiency. Utilizing a newly developed and highly sensitive method for mapping the genomic locations of a randomly integrated “sensor”, we identify specific epigenetic features that strongly correlate with the highly variable efficiency of prime editing across different genomic locations. Next, to assess the interaction of trans-acting factors with the cis-chromatin environment, we develop and apply a pooled genetic screening approach with which the impact of knocking down various DNA repair factors on prime editing efficiency can be stratified by cis-chromatin context. Finally, we demonstrate that we can dramatically modulate the efficiency of prime editing through epigenome editing, i.e. enhancing (or restricting) local chromatin accessibility in order to increase (or decrease) the efficiency of prime editing at a target site. Looking forward, we envision that the insights and tools described here will broaden the range of both basic research and therapeutic contexts in which prime editing is useful.
2023-04-12 | GSE228462 | GEO
Project description:Prime editing is a highly versatile CRISPR-based genome editing technology with the potential to correct the vast majority of genetic defects1. However, correction of a disease phenotype in vivo in somatic tissues has not been achieved yet. Here, we establish proof-of-concept for in vivo prime editing, that resulted in rescue of a metabolic liver disease. We first develop a size-reduced prime editor (PE) lacking the RNaseH domain of the reverse transcriptase (SpCas9-PERnH), and a linker- and NLS-optimized intein-split PE construct (SpCas9-PE p.1153) for delivery by adeno-associated viruses (AAV). Systemic dual AAV-mediated delivery of this variant in neonatal mice enables installation of a transversion mutation at the Dnmt1 locus with 15% efficiency on average. Next, we targeted the disease-causing mutation in the phenylalanine hydroxylase (Pah)enu2 mouse model for phenylketonuria (PKU). Correction rates of 1.5% using the dual AAV approach could be increased to up to 14% by delivery of full-length SpCas9-PE via adenoviral vector 5 (AdV5), leading to full restoration of physiological blood phenylalanine (L-Phe) levels below 120 µmol/L. Our study demonstrates in vivo prime editing in the liver at two independent loci, emphasizing the potential of PEs for future therapeutic applications.
2021-12-29 | GSE174757 | GEO
Project description:Prime editing is a versatile genome-editing technique that shows great promise for the generation and repair of patient mutations. However, some genomic sites are difficult to edit and optimal design of prime-editing tools remains elusive. Here we present a fluorescent prime editing and enrichment reporter (fluoPEER), which can be tailored to any genomic target site. This system rapidly and faithfully ranks the efficiency of prime edit guide RNAs (pegRNAs) combined with any prime editor variant. We apply fluoPEER to instruct correction of pathogenic variants in patient cells and find that plasmid-editing enriches for genomic editing up to 3-fold compared to conventional enrichment strategies. DNA repair and cell cycle-related genes are enriched in the transcriptome of edited cells. Stalling cells in the G1/S boundary increases prime editing efficiency up to 30%. Together, our results show that fluoPEER can be employed for rapid and efficient correction of patient cells, selection of gene-edited cells, and elucidation of cellular mechanisms needed for successful prime editing.
2022-02-03 | GSE195977 | GEO
Project description:We evaluate CRISPR-based prime editing for application in organoids. First we model mutations in TP53 in intestinal and hepatocyte oganoids and determine the efficiency and accuracy of mutation induction on multiple targets. Then, to evaluate potential clinical applicability of prime editing we repair mutations in the CFTR channel that cause cystic fibrosis in intestinal organoids. First we repair the CFTR-F508del mutation which is the most common mutation in cystic fibrosis. Then we compare adenine base editing to prime editing by repairing the CFTR-R785* mutation using both strategies.
| EGAS00001005358 | EGA
Project description:Purpose: Chinese hamster ovary (CHO) cells are a common tool utilized in bioproduction and directed genome engineering of CHO cells is of great interest to enhance recombinant cell lines. Until recently, this focus has been challenged by a lack of efficacious, high throughput, and low-cost gene editing modalities and screening methods. In this work, we demonstrate an improved method for gene editing in CHO cells using CRISPR RNPs and characterize the endpoints of Cas9 and ZFN mediated genetic engineering. Methods: Amplicons were first assayed for quality using an Invitrogen Quant-iT dsDNA (Thermo, Cat Q33120) assay and gel electrophoresis to determine DNA concentration and DNA quality. Samples were then used for Sanger sequence based decomposition or processed downstream using NGS. For NGS, libraries were generated using the Illumina TruSeq Nano DNA kit (Illumina, Cat: 20015964). The libraries were sequenced using the Illumina MiSeq platform, with read length of 2x150bp. 4.5Gb of sequencing data was generated per DNA sample. Results: There was a tendency for decomposition to underestimate editing as compared to NGS as the indel size became larger. Despite these results, sequence decomposition was able to reproduce next-generation data in the context of gene editing efficiency across a short amplicon. Conclusions: We took advantage of the differential Indel spectrums induced by both ZFN and CRISPR to validate metrics for assess gene editing and show how deconvolution-based methods, can be utilized in the context of cell line development.
2019-07-20 | GSE134559 | GEO
Project description:Emerging base and prime editing may provide safer and more precise genetic engineering than nuclease-based approaches bypassing the dependence on DNA double strand breaks (DSBs). However, little is known about cellular responses and genotoxicity. Here, we comparatively assessed state-of-the-art base and prime editors (B/PE) versus Cas9 in human hematopoietic stem/progenitor cells (HSPCs). BE and PE induced detrimental transcriptional responses constraining editing efficiency and/or HSPC repopulation in xenotransplants, albeit to a lesser extent than Cas9. DNA DSBs and their genotoxic byproducts, including deletions and translocations, were less frequent but not abrogated by BE and PE, particularly for cytidine BE due to suboptimal inhibition of base excision repair. Tailoring timing and B/PE expression enabled highly efficient and precise editing of long-term repopulating HSPCs. However, we uncovered a genome-wide effect of BEs on the mutational landscape of HSPCs, raising concerns for a potential genotoxic impact and calling for further investigations and improvements in view of clinical application.and/or HSPC repopulation in xenotransplants, albeit to a lesser extent than Cas9. DNA DSBs and their genotoxic byproducts, including deletions and translocations, were lower but not abrogated by BE and PE, particularly for cytidine BE upon suboptimal base excision repair inhibition. Tailoring timing and B/PE expression enabled highly efficient and precise editing of long-term repopulating HSPCs. However, we uncovered a genome-wide effect of cytidine BE on mutational landscape of hematopoietic grafts, raising concerns for its prospective clinical application. Conversely, the superior efficiency and precision of adenine BE built confidence on its entry into clinical arena.
2023-07-18 | GSE218462 | GEO