Браузер не даёт сохранять данные (например, приватный режим): закладки пропадут после закрытия вкладки.
Поиск статей PubMed
Ключевые слова, автор, журнал, годы — результаты из PubMed, аннотации с переводом на русский, закладки в браузере.
Найдено: 26 182
Страница 961 из 1000-
High-throughput genome editing in rice with a virus-based surrogate system.
With the widespread use of clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated nuclease (Cas) technologies in plants, large-scale genome editing is increasingly needed. Here, we developed a geminivirus-mediated surrogate system, called Wheat Dwarf Virus-Gate (WDV-surrogate), to facilitate high-throughput genome editing. WDV-Gate has two parts: one is the recipient callus from a transgenic rice line expressing Cas9 and a mutated hygromycin-resistant gene (HygM) for surrogate selection; the other is a WDV-based construct expressing two single guide RNAs (sgRNAs) targeting HygM and a gene of interest, respectively. We evaluated WDV-Gate on six rice loci by producing a total of 874 T0 plants. Compared with the conventional method, the WDV-Gate system, which was characterized by a transient and high level of sgRNA expression, significantly increased editing frequency (66.8% vs. 90.1%), plantlet regeneration efficiency (2.31-fold increase), and numbers of homozygous-edited plants (36.3% vs. 70.7%). Large-scale editing using pooled sgRNAs targeting the SLR1 gene resulted in a high editing frequency of 94.4%, further demonstrating its feasibility. We also tested WDV-Gate on sequence knock-in for protein tagging. By co-delivering a chemically modified donor DNA with the WDV-Gate plasmid, 3xFLAG peptides were successfully fused to three loci with an efficiency of up to 13%. Thus, by combining transiently expressed sgRNAs and a surrogate selection system, WDV-Gate could be useful for high-throughput gene knock-out and sequence knock-in.
-
CRISPR/Cas9-mediated B2m knockout paves the way for allogeneic basal cell transplantation.
BACKGROUND: Autologous transplantation of basal cells (BCs) has shown promise in treating respiratory diseases, but disease-specific subpopulations among BCs probably diminish the treatment efficacy. An alternative approach involves generating universal and healthy BCs, which offers a potentially more efficient and accessible solution for avoiding using abnormal BCs. However, such hypoimmunogenic BCs have not yet been transplanted into the airways of immunocompetent animals. METHODS: Before producing hypoimmunogenic BCs, the predominant transplantation antigen in BCs was explored through RT-qPCR and flow cytometry to identify the key target of CRISPR/Cas9‐mediated editing. The proliferation and expression of specific markers of BCs were evaluated after gene editing by CCK‐8 and RT‐qPCR, respectively. These gene‐edited BCs and wild‐type (WT) BCs, which were both derived from the same BALB/c mouse, were subsequently allogeneically transplanted into C57BL/6 mice with polidocanol‐induced airway injury to evaluate the differentiation and immune response in the recipient mice via immunehistological staining. RESULTS: In the present study, it was demonstrated that major histocompatibility complex class I (MHC-I) is the predominant transplantation antigen in BCs. The hypoimmunogenic BCs were generated through editing beta‐2 microglobulin (B2m) participating in the encoding of MHC‐I. The knockout of B2m in BCs did not affect their proliferation or the expression of specific markers in vitro. Both WT BCs and B2m‐edited BCs (B2m‾ BCs) successfully differentiated into ciliated and secretory cells in the tracheas following allogeneic transplantation and did not elicit an immune response during the 26‐day observation period in the tracheas. However, WT BCs, compared to B2m‾ BCs, induced severe lung injury by provoking an immune response in the lower airways and alveolar regions, as indicated by increased infiltration of CD45+ immune cells, epithelial cell shedding in the bronchi, and obvious alveolar hyperemia with collapse. CONCLUSIONS: The hypoimmunogenic BCs generated through CRISPR/Cas9-mediated B2m gene editing retained their ability to differentiate and maintained viability in the allogeneic respiratory system, supporting the potential application in the cell regeneration therapy of airway diseases.
-
Oligonucleotide Synthesis Errors Are a Source of Untoward Variation in HDR-Mediated Gene Editing.
Background/Objectives: Single-stranded oligonucleotides (ssODNs) are used as donor templates for therapeutic gene editing by CRISPR-Cas9 cleavage and homology-directed repair (HDR). Although ssODN sequence fidelity is critical to the safety and efficacy of editing, standard quality control methods cannot resolve individual nucleotide errors. Methods: We performed deep sequencing of ssODNs from three manufacturers and amplicons from edited hematopoietic stem/progenitor cells. Results: We find that synthesis errors are present in all ssODNs tested at rates that vary more than two-fold among manufacturers, at positions that are dependent on sequence context. These synthesis errors are propagated into the genome by HDR at frequencies proportional to their abundance in the ssODN. In our sickle cell mutation correction protocol, the most prevalent SNEs are predicted to produce benign β-globin variants, while the less frequent frameshift deletions are predicted to generate β-thalassemia-like alleles. Conclusions: Current quality control standards are insufficient to detect these errors, and deep sequencing of ssODNs should be incorporated into regulatory submissions for clinical gene editing programs.
-
A Simple and Low-Tech Heat-Shock Method to Increase Genome Editing Efficiency in Plants.
CRISPR/Cas is now the standard technique to generate novel plant genotypes. However, optimizing the efficiency of the system continues to be an aspect of research and development. One of the improvements for increasing mutagenesis efficiency in different species is the application of heat stress. However, many experimental setups are limited by the requirement of using dedicated climate chambers to impose heat stress and by difficulties in the phenotyping of soil-grown plants. Here, we describe a simplified heat stress assay for in vitro-grown plants that can be completed in 6 days using commonly available laboratory equipment. We show that three 24-hr heat shocks (3×HS) at 37°C alternated with 24 hr of recovery at 21°C efficiently increases indel rates of LbCas12a and Cas9. We illustrate how visual mutant phenotypes (pds3 and gl1) can assist in quantifying genome editing efficiency, and describe how to quantify genome editing efficiency using genotyping by Sanger sequencing. We also provide a support protocol to efficiently clone a CRISPR expression vector in a single step. Together, our methods allow researchers to increase CRISPR-induced mutations using a low-tech setup in plants. © 2022 Wiley Periodicals LLC. Basic Protocol 1: 3×HS protocol Basic Protocol 2: Genotyping by Sanger sequencing Support Protocol: One-step cloning of a CRISPR expression vector.
-
China sprints ahead in CRISPR therapy race.
-
Generation of Knock-In Mouse by Genome Editing.
Knock-in mice are useful for evaluating endogenous gene expressions and functions in vivo. Instead of the conventional gene-targeting method using embryonic stem cells, an exogenous DNA sequence can be inserted into the target locus in the zygote using genome-editing technology. In this chapter, I describe the generation of epitope-tagged mice using engineered endonuclease and single-strand oligodeoxynucleotide through the mouse zygote as an example of how to generate a knock-in mouse by genome editing.
-
Rewriting endogenous human transcripts with dual CRISPR-guided 3' trans-splicing.
Unlike genome editing, RNA editing offers the ability to transiently alter cells with minimal risk from off-target effects. While exon-skipping technologies can influence splice site selection, many desired perturbations to the transcriptome require replacement or addition of exogenous exons to target mRNAs, such as replacing disease-causing exons, repairing truncated proteins, or engineering protein fusions. Here, we report the development of RNA-guided trans-splicing with Cas editor (RESPLICE). RESPLICE uses two orthogonal RNA-targeting CRISPR effectors to co-localize a trans-splicing pre-mRNA and to inhibit the cis-splicing reaction, respectively. We demonstrate efficient, specific, and programmable trans-splicing of RNA cargo (up to 2.1 kb) into 11 endogenous transcripts across 3 cell types, achieving up to 45% trans-splicing efficiency in bulk or 90% when sorting for high effector expression. Our results present RESPLICE as a mode of RNA editing that could provide fine-tuned and transient control of cellular programs.
-
Intracellular biosensors by functional nanomaterial-integrated CRISPR technologies for real-time molecular sensing.
CRISPR technology, originally developed as a genome-editing tool, has recently emerged as a powerful platform for intracellular biosensing. By harnessing the programmability and target specificity of CRISPR-associated proteins, such as Cas9, Cas12, and Cas13, researchers have engineered biosensors capable of detecting a wide array of intracellular signals, including nucleic acids, non-coding RNAs, and small-molecule metabolites. This review discusses the recent advancements in CRISPR-powered biosensors for real-time, dynamic monitoring of cellular processes and molecular events. Particular focus is given to the integration of nanotechnology, which plays a crucial role in enhancing the delivery efficiency, signal amplification, and sensor stability. Nanomaterials such as gold nanoparticles, quantum dots, DNA nanostructures, and upconversion nanoparticles have been strategically employed to improve the intracellular transport of CRISPR components, facilitate signal readouts, and enable multimodal sensing in complex cellular environments. Additionally, we delve into how CRISPR-nanotechnology hybrids can be adapted for multiplex analysis and single-cell resolution. This review also addresses the current challenges in intracellular biosensing, including precise delivery, biocompatibility, and long-term monitoring, and outlines future directions for the application of these systems in precision medicine, synthetic biology, and advanced therapeutic monitoring. Through the convergence of gene-editing systems and nanotechnology, CRISPR-based intracellular biosensors are anticipated to revolutionize next-generation diagnostic and therapeutic strategies.
-
Discovering the Genome-Wide Activity of CRISPR-Cas Nucleases.
Originally discovered as part of an adaptive bacterial defense system against the invasion of foreign phages, programmable CRISPR-Cas nucleases have emerged as remarkable enzymes with transformative potential for both biological research and clinical application. CRISPR-Cas nucleases likely evolved in their natural context to tolerate imperfect specificity in order to recognize mutant bacteriophages. However, in the context of biological research and clinical applications, high specificity is generally preferred. For therapeutic applications in particular, it is important to carefully and empirically define the genome-wide activity of engineered nucleases, as hundreds of millions to billions of cells may be modified in a single therapeutic dose. Over the past several years, a number of both cell-based and in vitro sensitive and unbiased genome-scale methods to define CRISPR-Cas nuclease specificity have been developed. These methods will play important complementary roles in better understanding their global specificity profiles and identifying optimal nucleases for applications that demand high precision editing. Improving the sensitivity of mutation detection by next-generation sequencing, developing assays to define the functional consequences of unintended off-target activity nuclease activity, and understanding the consequences of individual human genetic variation on gene editing activity will be important areas for future research and development.
-
Generation of eight hiPSCs lines from two pathogenic variants in CACNA1A using the CRISPR-Cas9 gene editing technology.
Developmental and epileptic encephalopathies (DEEs) are rare severe neurodevelopmental disorders with a cumulative incidence of 1:6.000 live births. Many epileptic conditions arise from single nucleotide variants in CACNA1A (calcium voltage-gated channel subunit alpha1 A), encoding the CaV2.1 calcium channel subunit. Human induced pluripotent stem cells (hiPSCs) are an optimal choice for modeling DEEs, as they can be differentiated in vitro into diverse neuronal subpopulations. Here, we report the generation of hiPSC lines with two pathogenic CACNA1A variants c.1767C > T, p. (Arg589Cys), referred to as R589C and c. 2139G > A, p.(Ala713Thr), referred to as A713T, previously associated with epilepsy. The variants were introduced into a hiPSC line from a healthy individual via CRISPR-Cas9 gene editing technology.
PubMed отдаёт не больше 10 000 первых результатов — уточните запрос, чтобы увидеть остальные.