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: 26 137
Страница 339 из 1000-
Non-viral and viral delivery systems for CRISPR-Cas9 technology in the biomedical field.
The clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR-Cas9) system provides a novel genome editing technology that can precisely target a genomic site to disrupt or repair a specific gene. Some CRISPR-Cas9 systems from different bacteria or artificial variants have been discovered or constructed by biologists, and Cas9 nucleases and single guide RNAs (sgRNA) are the major components of the CRISPR-Cas9 system. These Cas9 systems have been extensively applied for identifying therapeutic targets, identifying gene functions, generating animal models, and developing gene therapies. Moreover, CRISPR-Cas9 systems have been used to partially or completely alleviate disease symptoms by mutating or correcting related genes. However, the efficient transfer of CRISPR-Cas9 system into cells and target organs remains a challenge that affects the robust and precise genome editing activity. The current review focuses on delivery systems for Cas9 mRNA, Cas9 protein, or vectors encoding the Cas9 gene and corresponding sgRNA. Non-viral delivery of Cas9 appears to help Cas9 maintain its on-target effect and reduce off-target effects, and viral vectors for sgRNA and donor template can improve the efficacy of genome editing and homology-directed repair. Safe, efficient, and producible delivery systems will promote the application of CRISPR-Cas9 technology in human gene therapy.
-
[Cas9 protein variant VQR recognizes NGAC protospacer adjacent motif in rice].
Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system is the third-generation genome editing tools that was developed and widely used in recent years. However, Streptococcus pyogenes Cas9 (SpCas9) in this system could only recognize NGG PAM (protospacer adjacent motif), which largely restricts the range of genome editing. The VQR (D1135V/R1335Q/T1337R) variant of SpCas9 could recognize NGAA, NGAG and NGAT PAMs in rice. However, whether VQR variant could recognize NGAC PAM remains unclear. In this study, three low editing efficiency sites of the VQR variant, NAL1-Q1, NAL1-Q2 and LPA1-Q, were selected for genome editing using the improved CRISPR/VQR system. The improved CRISPR/VQR system effectively edited these target sites, and the gene editing efficiency was 9.75%, 43.90% and 29.26% respectively. To ensure the recognition of NGAC PAM by the improved CRISPR/VQR system, two NGAC PAM containing sites (NAL-C and GL1-C) in the NARROW LEAF 1 (NAL1) for leaf length and GLOSSY1 (GL1) genes for wax biosynthesis were selected for genome editing in rice in this study, and 57 transgenic plants were obtained. The PCR amplification and sequencing results showed that 27 plants (47.36%) had mutation in the NAL1-C site, 44 plants (77.19%) had mutation in the GL1 gene, and 26 plants (45.61%) had mutation in the NAL-C and GL1-C sites. Further analysis revealed that there were four types of mutations caused by the CRISPR/VQR system, respectively for the hybrid mutation, biallelic mutation, chimeric mutation and homozygous mutations. Among them, heterozygous mutation and biallelic mutation were dominant changes. These results indicated that the improved CRISPR/VQR system could efficiently edit the NGAC PAM sites of the rice and produce abundant mutant types. This study provides a theoretical basis for NGAC PAM editing in rice and other related plants.
-
ExsgRNA: reduce off-target efficiency by on-target mismatched sgRNA.
Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing technology has been widely used to facilitate efficient genome editing. Current popular sgRNA design tools only consider the sgRNA perfectly matched to the target site and provide the results without any on-target mismatch. We suppose taking on-target gRNA-DNA mismatches into consideration might provide better sgRNA with similar binding activity and reduced off-target sites. Here, we trained a seq2seq-attention model with feedback-loop architecture, to automatically generate sgRNAs with on-target mismatches. Dual-luciferase reporter experiment showed that multiple sgRNAs with three mismatches could achieve the 80% of the relative activity of the perfect matched sgRNA. Meanwhile, it could reduce the number of off-target sites using sgRNAs with on-target mismatches. Finally, we provided a freely accessible web server sgRNA design tool named ExsgRNA. Users could submit their target sequence to this server and get optimal sgRNAs with less off-targets and similar on-target activity compared with the perfect-matched sgRNA.
-
Endometriosis: Future Biological Perspectives for Diagnosis and Treatment.
Endometriosis is an oestrogen-dependent inflammatory disease affecting menstruating women, with varying levels of severity. Oestrogen dysregulation is responsible for chronic inflammation, angiogenesis, endometrial lesion development, progression, and infertility during menarche in afflicted women. The inflammatory mediators associated with this chronic painful disease have been established, with research also indicating the relationship between dysbiosis and disease manifestation. Endometriosis is also present with several painful comorbidities, including endometrial cancer, cardiovascular disease, and autoimmunity. The lack of specific and sensitive non-invasive diagnostic procedures, coupled with poor response to current therapeutic approaches, means that treatment needs remain unmet. Surgical procedures are performed to remove endometriosis ectopic lesions, for which the recurrence rate of disease is up to 50%, with certain patients exhibiting no alleviation of symptoms. This review aims to outline the aetiology of endometriosis, detailing novel diagnostic approaches and potential therapeutic approaches, namely advanced therapeutic medical products (ATMPs), including stem cell therapy and clustered regularly interspaced short palindromic repeats (CRISPR) gene editing. This timely review also provides novel insights into the important recent modalities which may be applied for the diagnosis and therapeutic response of endometriosis, including biomarkers, microfluidic platforms, and organoid systems. Undoubtedly, reliable, reproducible, sensitive, and specific models of endometriosis in humans are urgently needed to investigate and detail the aetiology of this debilitating disease.
-
Current application and future prospects of CRISPR-Cas in lactic acid Bacteria: A review.
Lactic acid bacteria (LABs) have a long history of use in food and beverages fermentation. Recently, several LABs have gained attention as starter or non-starter cultures and probiotics for making functional fermented foods, which have the potential to enhance human health. In addition, certain LABs show great potential as microbial cell factories for producing food-related chemicals. However, enhancing the outcomes of starter and non-starter cultures, exploring the complicated probiotic mechanism of LABs, and engineering strains to enhance the yields of high-value compounds for precision fermentation remains challenging due to the time-consuming and labor-intensive current genome editing tools. The clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated proteins (Cas) system, originally an adaptive immune system in bacteria, has revolutionized genome editing, metabolic engineering and synthetic biology. Its versatility has resulted in extensive applications across diverse organisms. The widespread distribution of CRISPR-Cas systems and the diversity of CRISPR arrays in LAB genomes highlight their potential for studying the evolution of LABs. This review discusses the current advancement of CRISPR-Cas systems in engineering LABs for food application. Moreover, it outlines future research directions aimed at harnessing CRISPR-Cas systems to advance lactic acid bacterial research and drive innovation in food science.
-
Efficient and allele-specific genome editing of disease loci in human iPSCs.
Efficient and precise genome editing is crucial for realizing the full research and therapeutic potential of human induced pluripotent stem cells (iPSCs). Engineered nucleases including CRISPR/Cas9 and transcription activator like effector nucleases (TALENs) provide powerful tools for enhancing gene-targeting efficiency. In this study, we investigated the relative efficiencies of CRISPR/Cas9 and TALENs in human iPSC lines for inducing both homologous donor-based precise genome editing and nonhomologous end joining (NHEJ)-mediated gene disruption. Significantly higher frequencies of NHEJ-mediated insertions/deletions were detected at several endogenous loci using CRISPR/Cas9 than using TALENs, especially at nonexpressed targets in iPSCs. In contrast, comparable efficiencies of inducing homologous donor-based genome editing were observed at disease-associated loci in iPSCs. In addition, we investigated the specificity of guide RNAs used in the CRISPR/Cas9 system in targeting disease-associated point mutations in patient-specific iPSCs. Using myeloproliferative neoplasm patient-derived iPSCs that carry an acquired JAK2-V617F point mutation and α1-antitrypsin (AAT) deficiency patient-derived iPSCs that carry an inherited Z-AAT point mutation, we demonstrate that Cas9 can specifically target either the mutant or the wild-type allele with little disruption at the other allele differing by a single nucleotide. Overall, our results demonstrate the advantages of the CRISPR/Cas9 system in allele-specific genome targeting and in NHEJ-mediated gene disruption.
-
CRISPR-Cas9: a prominent genome editing tool in the management of inherited blood disorders and hematological malignancies.
Several hematologic diseases with genetic defects, like sickle cell disease and β-thalassemia can be treated with allogeneic hematopoietic stem cell transplantation (HSCT) from healthy donors. However, suitable tissue-matched donors are often unavailable, and HSCT involves risks such as graft-versus-host disease and potential disease relapse. Due to the genetic heterogeneity of blood disorders and the complexity of the hematopoietic system, identifying effective genes for managing and treating both benign and malignant conditions remains a significant challenge. The genome editing field is rapidly expanding and is essential for identifying genetic factors in pathological processes. These developments highlight the importance of using ex vivo gene therapy approaches for autologous hematopoietic stem cells. Also, gene editing technologies are gaining significant interest in engineered cell therapies for hematological malignancies . Today, various programmable nucleases are available for genome editing, with the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system standing out due to its high efficiency, low cytotoxicity, cost-effectiveness, and precision. This system can serve as a genomic modification tool for treating blood disorders, including hereditary diseases and immunotherapy for cancer using chimeric antigen receptor T cells (CAR-T cells). Advancements in CRISPR-Cas9 are expected to significantly impact medical research and clinical applications. However, challenges such as off-target effects and immunogenicity must be addressed. This review summarizes the mechanism and delivery strategies of CRISPR-Cas9, discusses its applications in treating inherited blood disorders such as sickle cell disease, β-thalassemia, and fanconi anemia, as well as hematological malignancies, and highlights the associated challenges.
-
Tumor microenvironment based stimuli-responsive CRISPR/Cas delivery systems: A viable platform for interventional approaches.
The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems have emerged as robust tools in cancer gene therapy due to their simplicity and versatility. Nevertheless, the genome editing efficiency in tumor sites and the clinical applications of CRISPR/Cas have been compromised by non-specific delivery and genotoxicity. Recently, intelligent delivery systems incorporating sensitive materials in response to endogenous stimuli of the tumor microenvironment (TME) have represented viable platforms for tumor-specific genome editing and reduced side effects of CRISPR/Cas. Spurred by this promising direction, this review first introduces the CRISPR/Cas systems widely employed in cancer therapeutic explorations. Various types of CRISPR/Cas delivery systems sensitive to the stimuli in TME and typical dual-/multiple-responsive CRISPR/Cas carriers are further discussed, emphasizing the correlations between sensitive components and spatiotemporal delivery mechanisms. The genome editing efficiencies of CRISPR/Cas-loaded stimuli-responsive carriers are also summarized both in vitro and in vivo. Collectively, stimuli-responsive CRISPR/Cas delivery systems hold great promise for potent cancer gene therapy.
-
Genome Editing by Grafting.
Grafting is the process of joining parts of two plants, allowing the exchange of molecules such as small RNAs (including microRNAs and small interfering RNAs), messenger RNAs, and proteins between the rootstock and the scion. Genome editing by grafting exploits RNAs, such as tRNA-like sequences (TLS motifs), to deliver the components (RNA) of the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system from transgenic rootstock to wild-type scion. The complex Cas9 protein and sgRNA-TLS produced in the scion perform the desired modification without the integration of foreign DNA in the plant genome, resulting in heritable transgene-free genome editing. In this review, we examine the current state of the art of this innovation and how it helps address regulatory problems, improves crop recovery and selection, exceeds the usage of viral vectors, and may reduce potential off-target effects. We also discuss the promise of genome editing by grafting for plants recalcitrant to in vitro culture and for agamic-propagated species that must maintain heterozygosity for plant productivity, fruit quality, and adaptation. Furthermore, we explore the limitations of this technique, including variable efficiency, graft incompatibility among genotypes, and challenges in large-scale application, while highlighting its considerable potential for further improvement and future broader applications for crop breeding.
-
Production of MSTN-mutated cattle without exogenous gene integration using CRISPR-Cas9.
Many genome-edited animals have been produced using clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 technology to edit specific genes. However, there are few guidelines for the application of this technique to cattle. The goal of this study was to produce trait-improved cattle using the genome-editing technology CRISPR-Cas9. Myostatin (MSTN) was selected as a target locus, and synthetic mRNA of sgRNA and Cas9 were microinjected into fertilized bovine embryos in vitro. As a result, 17 healthy calves were born, and three of them showed MSTN mutation rates of 10.5%, 45.4%, and 99.9%, respectively. Importantly, the offspring with the 99.9% MSTN mutation rate had a biallelic mutation (-12 bps) and a double-muscling phenotype. In conclusion, we demonstrate that the genome-editing technology CRISPR-Cas9 can produce genetically modified calves with improved traits.
PubMed отдаёт не больше 10 000 первых результатов — уточните запрос, чтобы увидеть остальные.