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BACKGROUND: For patients who have difficulty controlling blood glucose even with insulin administration, xenogeneic islet cells, including human stem cell-derived pancreatic islets (hSC-islet) and porcine islets, have garnered attention as potential solutions to challenges associated with donor shortages. For the development of diabetes treatment modalities that use cell transplantation therapy, it is essential to evaluate the efficacy and safety of transplanted cells using experimental animals over the long term. METHODS: We developed permanent diabetic immune-deficient mice by introducing the Akita (C96Y) mutation into the rodent-specific Insulin1 gene of NOD/Shi-scid IL2rγcnull (NOG) mice (Ins1C96Y/C96Y NOG). Their body weight, nonfasting blood glucose, and survival were measured from 4 wk of age. Insulin sensitivity was assessed via tolerance tests. To elucidate the utility of these mice in xenotransplantation experiments, we transplanted hSC-islet cells or porcine islets under the kidney capsules of these mice. RESULTS: All male and female homozygous mice exhibited persistent severe hyperglycemia associated with ß-cell depletion as early as 4 wk of age and exhibited normal insulin sensitivity. These mice could be stably engrafted with hSC-islets, and the mice that received porcine islet grafts promptly exhibited lowered blood glucose levels, maintaining blood glucose levels below the normal glucose range for at least 52 wk posttransplantation. CONCLUSIONS: The Ins1C96Y/C96Y NOG mouse model provides an effective platform to assess both the efficacy and safety of long-term xenograft engraftment without the interference of their immune responses. This study is expected to contribute essential basic information for the clinical application of islet cell transplantation.
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OBJECTIVES: We evaluated the efficacy and safety of cyanoacrylate closure (CAC) for endovascular treatment of varicose veins with cyanoacrylate adhesive (VenaSeal® closure system) in Japan. METHODS: A multicenter prospective consecutive registry study was conducted at 12 centers in Japan on 125 patients with primary varicose veins who underwent CAC. The patients were evaluated on target vein occlusion, postoperative complications, Visual Analogue Scale (VAS) for pain, revised Venous Clinical Severity Score (rVCSS), Aberdeen Varicose Vein Questionnaire (AVVQ), and EuroQol 5 dimensions 5-level (EQ-5D-5L) for 1-year after the surgery. RESULTS: The closure rate was 92.6% at 1 year postoperatively, and 95.0% and 90.2% for GSV and SSV respectively with little difference (p = .491). The mean VAS in the immediate postoperative period was 18.9 ± 23.4. Postoperative complications were observed in 20 patients (16%). Hypersensitivity-type phlebitis occurred in 7 patients (5.6%). Infection of the treated vein resulted in resection of GSV. The rVCSS and AVVQ improved significantly after 90 days and 1 year postoperatively (p < .001), while the EQ-5D-5L have not changed. CONCLUSION: Cyanoacrylate Closure was considered generally a safe and minimally invasive treatment with good mid-term outcomes including SSV. However further study is required for some CAC specific complications.
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A large number of recombinant plasmids for the yeast Saccharomyces cerevisiae have been constructed and accumulated over the past four decades. It is desirable to apply the recombinant plasmid resources to Saccharomyces sensu stricto species group, which contains an increasing number of natural isolate and industrial strains. The application to the group encounters a difficulty. Natural isolates and industrial strains are exclusively prototrophic and polyploid, whereas direct application of most conventional plasmid resources imposes a prerequisite in host yeast strains of an auxotrophic mutation (i.e., leu2) that is rescued by a selection gene (e.g., LEU2) on the recombinant plasmids. To solve the difficulty, we aimed to generate leu2 mutants from yeast strains belonging to the yeast Saccharomyces sensu stricto species group by DNA editing. First, we modified an all-in-one type CRISPR-Cas9 plasmid pML104 by adding an antibiotic-resistance gene and designing guide sequences to target the LEU2 gene and to enable wide application in this yeast group. Then, the resulting CRISPR-Cas9 plasmids were exploited to seven strains belonging to five species of the group, including natural isolate, industrial, and allopolyploid strains. Colonies having the designed mutations in the gene appeared successfully by introducing the plasmids and assisting oligonucleotides to the strains. Most of the plasmids and resultant leu2- mutants produced in this study will be deposited in several repository organizations. KEY POINTS: ⢠All-in-one type CRISPR-Cas9 plasmids targeting LEU2 gene were designed for broad application to Saccharomyces sensu stricto group species strains ⢠Application of the plasmids generated leu2 mutants from strains including natural isolates, industrial, and allopolyploid strains ⢠The easy conversion to leu2 mutants permits free access to recombinant plasmids having a LEU2 gene.
Sujet(s)
Systèmes CRISPR-Cas , Édition de gène , Mutation , Plasmides , Polyploïdie , Plasmides/génétique , Édition de gène/méthodes , Protéines de Saccharomyces cerevisiae/génétique , Saccharomyces/génétique , Saccharomyces cerevisiae/génétique , 3-Isopropylmalate dehydrogenase/génétique , 3-Isopropylmalate dehydrogenase/métabolisme , Génome fongique/génétiqueRÉSUMÉ
The synthesis of protected precursors of cyclic ß-1,6-oligoglucosamines from thioglycosides as monomers is performed by electrochemical polyglycosylation. The monomer with a 2,3-oxazolidinone protecting group afforded the cyclic disaccharide exclusively. Cyclic oligosaccharides up to the trisaccharide were obtained using the monomer with a 2-azido-2-deoxy group.
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The current guidelines for acute coronary syndrome (ACS) discourage the use of anticoagulation after percutaneous coronary intervention (PCI) without specific indications, although the recommendation is not well supported by evidence. In this post hoc analysis of the ShorT and OPtimal Duration of Dual AntiPlatelet Therapy-3 (STOPDAPT-3) trial, 30-day outcomes were compared between the 2 groups with and without post-PCI heparin administration among patients with ACS who did not receive mechanical support devices. The co-primary end points were the bleeding end point, defined as the Bleeding Academic Research Consortium type 3 or 5 bleeding, and the cardiovascular end point, defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke. Among 4,088 patients with ACS, 2,339 patients (57.2%) received post-PCI heparin. The proportion of patients receiving post-PCI heparin was higher among those with ST-elevation myocardial infarction compared with others (72.3% and 38.8%, p <0.001), and among patients with intraprocedural adverse angiographic findings compared with those without (67.6% and 47.5%, p <0.001). Post-PCI heparin compared with no post-PCI heparin was associated with a significantly increased risk of the bleeding end point (4.75% and 2.52%, adjusted hazard ratio 1.69, 95% confidence interval 1.15 to 2.46, p = 0.007) and a numerically increased risk of the cardiovascular end point (3.16% and 1.72%, adjusted hazard ratio 1.56, 95% confidence interval 0.98 to 2.46, p = 0.06). Higher hourly dose or total doses of heparin were also associated with higher incidence of both bleeding and cardiovascular events within 30 days. In conclusion, post-PCI anticoagulation with unfractionated heparin was frequently implemented in patients with ACS. Post-PCI heparin use was associated with harm in terms of increased bleeding without the benefit of reducing cardiovascular events. Trial identifier: STOPDAPT-3 ClinicalTrials.gov number, NCT04609111.
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Fibrocartilaginous entheses consist of tendons, unmineralized and mineralized fibrocartilage, and subchondral bone, each exhibiting varying stiffness. Here we examined the functional role of sclerostin, expressed in mature mineralized fibrochondrocytes. Following rapid mineralization of unmineralized fibrocartilage and concurrent replacement of epiphyseal hyaline cartilage by bone, unmineralized fibrocartilage reexpanded after a decline in alkaline phosphatase activity at the mineralization front. Sclerostin was co-expressed with osteocalcin at the base of mineralized fibrocartilage adjacent to subchondral bone. In Scx-deficient mice with less mechanical loading due to defects of the Achilles tendon, sclerostin+ fibrochondrocyte count significantly decreased in the defective enthesis where chondrocyte maturation was markedly impaired in both fibrocartilage and hyaline cartilage. Loss of the Sost gene, encoding sclerostin, elevated mineral density in mineralized zones of fibrocartilaginous entheses. Atomic force microscopy analysis revealed increased fibrocartilage stiffness. These lines of evidence suggest that sclerostin in mature mineralized fibrochondrocytes acts as a modulator for mechanical tissue integrity of fibrocartilaginous entheses.
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BACKGROUND: The impact of very low baseline levels of low-density lipoprotein cholesterol (LDL-C) on patients with coronary artery disease remains unclear. METHOD: We enrolled 39,439 patients of the pooled population from the CREDO-Kyoto registries Cohorts 1, 2, and 3. The study population consisted of 33,133 patients who had undergone their first coronary revascularization. We assessed the risk for mortality and cardiovascular events according to quintiles of the baseline LDL-C levels. RESULTS: Patients in the very low LDL-C quintile (<85â¯mg/dL) had more comorbidities than those in the other quintiles. Lower LDL-C levels were strongly associated with anemia, thrombocytopenia, and end-stage renal disease. The cumulative 4-year incidence of all-cause death increased as LDL-C levels decreased (very low: 19.4â¯%, low: 14.5â¯%, intermediate: 11.1â¯%, high: 10.0â¯%, and very high: 9.2â¯%; pâ¯<â¯0.001), which was driven by both the early and late events. After adjusting for baseline characteristics, the adjusted risks of the very low and low LDL-C quintiles relative to the intermediate LDL-C quintile remained significant for all-cause death (very low: HR 1.29, 95â¯% CI 1.16-1.44, pâ¯<â¯0.001; low: HR 1.15, 95â¯% CI 1.03-1.29, pâ¯=â¯0.01). The excess adjusted risks of the lowest LDL-C quintile relative to the intermediate LDL-C quintile were significant for clinical outcomes such as cardiovascular death (HR 1.17, 95â¯% CI 1.01-1.35), non-cardiovascular death (HR 1.35, 95â¯% CI 1.15-1.60), sudden death (HR 1.44, 95â¯% CI 1.01-2.06), and heart failure admission (HR 1.11 95â¯% CI 1.01-1.22), while there was no excess risk for the lowest LDL-C quintile relative to the intermediate LDL-C quintile for myocardial infarction and stroke. CONCLUSIONS: Lower baseline LDL-C levels were associated with more comorbidities and a significantly higher risk of death, regardless of cardiovascular or non-cardiovascular causes, in patients who underwent coronary revascularization.
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Glycerophosphocholine (GPC) is an important precursor for intracellular choline supply in phosphatidylcholine (PC) metabolism. GDE5/Gpcpd1 hydrolyzes GPC into choline and glycerol 3-phosphate; this study aimed to elucidate its physiological function in vivo. Heterozygous whole-body GDE5-deficient mice reveal a significant GPC accumulation across tissues, while homozygous whole-body knockout results in embryonic lethality. Skeletal muscle-specific GDE5 deletion (Gde5 skKO) exhibits reduced passive force and improved fatigue resistance in electrically stimulated gastrocnemius muscles in vivo. GDE5 deficiency also results in higher glycolytic metabolites and glycogen levels, and glycerophospholipids alteration, including reduced levels of phospholipids that bind polyunsaturated fatty acids (PUFAs), such as DHA. Interestingly, this PC fatty acid compositional change is similar to that observed in skeletal muscles of denervated and Duchenne muscular dystrophy mouse models. These are accompanied by decrease of GDE5 expression, suggesting a regulatory role of GDE5 activity for glycerophospholipid profiles. Furthermore, a DHA-rich diet enhances contractile force and lowers fatigue resistance, suggesting a functional relationship between PC fatty acid composition and muscle function. Finally, skinned fiber experiments show that GDE5 loss increases the probability of the ryanodine receptor opening and lowers the maximum Ca2+-activated force. Collectively, GDE5 activity plays roles in PC and glucose/glycogen metabolism in skeletal muscle.
Sujet(s)
Souris knockout , Contraction musculaire , Muscles squelettiques , Phosphatidylcholines , Animaux , Muscles squelettiques/métabolisme , Souris , Phosphatidylcholines/métabolisme , Mâle , Souris de lignée C57BL , PhosphodiesterasesRÉSUMÉ
We previously reported that solute carrier family 22 member 18 (Slc22a18) regulates lipid accumulation in 3T3-L1 adipocytes. Here, we provide additional evidence derived from experiments with adenoviral vector expression and genetic manipulation of mice. In primary cultured rat hepatocytes, adenoviral overexpression of mouse Slc22a18 increased triglyceride accumulation and triglyceride synthetic activity, which was decreased in an adenoviral knockdown experiment. Adenoviral overexpression of mouse Slc22a18 in vivo caused massive fatty liver in mice, even under normal dietary conditions. Conversely, adenoviral knockdown of mouse Slc22a18 reduced hepatic lipid accumulation induced by a high-glucose and high-sucrose diet. We created Slc22a18 knockout mice, which grew normally and showed no obvious spontaneous phenotypes. However, compared with control littermates, the knockout mice exhibited decreased hepatic triglyceride content under refeeding conditions, significantly reduced epididymal fat mass, and tended to have lower liver weight in conjunction with leptin deficiency. Finally, we created transgenic mice overexpressing rat Slc22a18 in an adipose-specific manner, which had increased body weight and epididymal fat mass primarily because of increased adipocyte cell volume. In these transgenic mice, a positive correlation was observed between adiposity and the expression levels of the rat Slc22a18 transgene. Taken together, these results indicate that Slc22a18 has positive effects on lipid accumulation in vivo.
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Transporteurs de cations organiques , Animaux , Souris , Rats , Mâle , Transporteurs de cations organiques/métabolisme , Transporteurs de cations organiques/génétique , Souris knockout , Hépatocytes/métabolisme , Triglycéride/métabolisme , Souris transgéniques , Métabolisme lipidique/génétique , Stéatose hépatique/métabolisme , Stéatose hépatique/génétique , Stéatose hépatique/anatomopathologie , Souris de lignée C57BL , Foie/métabolisme , Adiposité/génétique , Adipocytes/métabolisme , Tissu adipeux/métabolisme , Cellules cultivées , Rat Sprague-DawleyRÉSUMÉ
The update of the draft genome assembly of sea urchin, Hemicentrotus pulcherrimus, which is widely studied in East Asia as a model organism of early development, was performed using Oxford nanopore long-read sequencing. The updated assembly provided ~600-Mb genome sequences divided into 2,163 contigs with N50 = 516 kb. BUSCO completeness score and transcriptome model mapping ratio (TMMR) of the present assembly were obtained as 96.5% and 77.8%, respectively. These results were more continuous with higher resolution than those by the previous version of H. pulcherrimus draft genome, HpulGenome_v1, where the number of scaffolds = 16,251 with a total of ~100 Mb, N50 = 143 kb, BUSCO completeness score = 86.1%, and TMMR = 55.4%. The obtained genome contained 36,055 gene models that were consistent with those in other echinoderms. Additionally, two tandem repeat sequences of early histone gene locus containing 47 copies and 34 copies of all histone genes, and 185 of the homologous sequences of the interspecifically conserved region of the Ars insulator, ArsInsC, were obtained. These results provide further advance for genome-wide research of development, gene regulation, and intranuclear structural dynamics of multicellular organisms using H. pulcherrimus.
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Génome , Animaux , Génome/génétique , Hemicentrotus/génétique , Séquençage nucléotidique à haut débit/méthodesRÉSUMÉ
Understanding and characterizing semi-crystalline models with crystalline and amorphous segments is crucial for industrial applications. A coarse-grained molecular dynamics (CGMD) simulations study probed the crystal network formation in high-density polyethylene (HDPE) from melt, and shed light on tensile properties for microstructure analysis. Modified Paul-Yoon-Smith (PYS/R) forcefield parameters are used to compute the interatomic forces among the PE chains. The isothermal crystallization at 300 K and 1 atm predicts the multi-nucleus crystal growth; moreover, the lamellar crystal stems and amorphous region are alternatively oriented. A one-dimensional density distribution along the alternative lamellar stems further confirms the ordering of the lamellar-stack orientation. Using this plastic model preparation approach, the semi-crystalline model density (ρcr) of ca. 0.913 g·cm-3 and amorphous model density (ρam) of ca. 0.856 g·cm-3 are obtained. Furthermore, the ratio of ρcr/ρam ≈ 1.06 is in good agreement with computational (≈1.096) and experimental (≈1.14) data, ensuring the reliability of the simulations. The degree of crystallinity (χc) of the model is ca. 52% at 300 K. Nevertheless, there is a gradual increase in crystallinity over the specified time, indicating the alignment of the lamellar stems during crystallization. The characteristic stress-strain curve mimicking tensile tests along the z-axis orientation exhibits a reversible sharp elastic regime, tensile strength at yield ca. 100 MPa, and a non-reversible tensile strength at break of 350%. The cavitation mechanism embraces the alignment of lamellar stems along the deformation axis. The study highlights an explanatory model of crystal network formation for the PE model using a PYS/R forcefield, and it produces a microstructure with ordered lamellar and amorphous segments with robust mechanical properties, which aids in predicting the microstructure-mechanical property relationships in plastics under applied forces.
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Background: This study aimed to assess the completion rate and postoperative bleeding incidence of endoscopic submucosal dissection (ESD) for gastric tumors under continuous antithrombotic therapy. Methods: A prospective observational study was conducted including 88 patients with 100 gastric lesions who underwent gastric endoscopic submucosal dissection (ESD) and received continuous antithrombotic therapy. Additionally, retrospective data on gastric ESD in 479 patients with 534 lesions who did not receive antithrombotic therapy were collected for comparison. Results: The en bloc resection rates (100% in the continuous antithrombotic therapy group vs. 100% in the non-antithrombotic therapy group) and complete resection rates (97.0% vs. 96.3%, respectively) were high and comparable between the groups. No significant differences were found in the specimen size or procedure time. Perforation rates were low (0% vs. 2.3%, respectively) and were not significantly different between the groups. However, postoperative bleeding occurred significantly more frequently in the continuous antithrombotic therapy group (10.2% vs. 4.2%, respectively) than in the non-antithrombotic therapy group. The subgroup analysis revealed a higher incidence of postoperative bleeding in patients receiving thienopyridine derivatives. Conclusions: Continuous administration of antithrombotic agents, especially thienopyridines, increased the risk of postprocedural hemorrhage following gastric ESD. These findings support the need for careful consideration of pharamcological management before ESD, aligning with the current guidelines.
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Genome Editing is widely used in biomedical research and medicine. Zinc finger nucleases (ZFNs) are smaller in size than transcription activator-like effector (TALE) nucleases (TALENs) and CRISPR-Cas9. Therefore, ZFN-encoding DNAs can be easily packaged into a viral vector with limited cargo space, such as adeno-associated virus (AAV) vectors, for in vivo and clinical applications. ZFNs have great potential for translational research and clinical use. However, constructing functional ZFNs and improving their genome editing efficiency is extremely difficult. Here, the efficient construction of functional ZFNs and the improvement of their genome editing efficiency using AlphaFold, Coot, and Rosetta are described. Plasmids encoding ZFNs consisting of six fingers using publicly available zinc-finger resources are assembled. Two functional ZFNs from the ten ZFNs tested are successfully obtained. Furthermore, the engineering of ZFNs using AlphaFold, Coot, or Rosetta increases the efficiency of genome editing by 5%, demonstrating the effectiveness of engineering ZFNs based on structural modeling.
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Édition de gène , Nucléases à doigts de zinc , Édition de gène/méthodes , Nucléases à doigts de zinc/génétique , Nucléases à doigts de zinc/métabolisme , Humains , Doigts de zinc/génétique , Systèmes CRISPR-Cas/génétiqueRÉSUMÉ
Sea urchins have been used as model organisms in developmental biology research and the genomes of several sea urchin species have been sequenced. Recently, genome editing technologies have become available for sea urchins, and methods for gene knockout using the CRISPRCas9 system have been established. Heliocidaris crassispina is an important marine fishery resource with edible gonads. Although H. crassispina has been used as a biological research material, its genome has not yet been published, and it is a non-model sea urchin for molecular biology research. However, as recent advances in genome editing technology have facilitated genome modification in non-model organisms, we applied genome editing using the CRISPR-Cas9 system to H. crassispina. In this study, we targeted genes encoding ETS transcription factor (HcEts) and pigmentation-related polyketide synthase (HcPks1). Gene fragments were isolated using primers designed by inter-specific sequence comparisons within Echinoidea. When Ets gene was targeted using two sgRNAs, one successfully introduced mutations and impaired skeletogenesis. In the Pks1 gene knockout, when two sgRNAs targeting the close vicinity of the site corresponding to the target site that showed 100% mutagenesis efficiency of the Pks1 gene in Hemicentrotus pulcherrimus, mutagenesis was not observed. However, two other sgRNAs targeting distant sites efficiently introduced mutations. In addition, Pks1 knockout H. crassispina exhibited an albino phenotype in the pluteus larvae and adult sea urchins after metamorphosis. This indicates that the CRISPRCas9 system can be used to modify the genome of the non-model sea urchin H. crassispina.
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Anthocidaris , Animaux , Anthocidaris/génétique , Systèmes CRISPR-Cas , , Techniques de knock-out de gènes , Echinoidea/génétique , Édition de gène/méthodesRÉSUMÉ
Metal carbonate hydroxides have emerged as novel and promising candidates for water splitting due to their good electrochemical properties and eco-friendly features. In this study, the hierarchical mesoporous structure of nickel carbonate hydroxide hydrate (Ni2(CO3)(OH)2·4H2O) was synthesized by a one-pot facile hydrothermal method. It demonstrated photocatalytic properties for the first time, exhibiting a hydrogen evolution reaction yield of 10 µmol g-1 h-1 under white light irradiation with a nominal power of 0.495 W. This facile synthesis strategy and the good photocatalytic properties indicate that nickel carbonate hydroxide is a promising material for application in photocatalytic hydrogen evolution.
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Since the manufacture, import, and use of asbestos products have been completely abolished in Japan, the main cause of asbestos emissions into the atmosphere is the demolition and removal of buildings built with asbestos-containing materials. To detect and correct asbestos emissions from inappropriate demolition and removal operations at an early stage, a rapid method to measure atmospheric asbestos fibers is required. The current rapid measurement method is a combination of short-term atmospheric sampling and phase-contrast microscopy counting. However, visual counting takes a considerable amount of time and is not sufficiently fast. Using artificial intelligence (AI) to analyze microscope images to detect fibers may greatly reduce the time required for counting. Therefore, in this study, we investigated the use of AI image analysis for detecting fibers in phase-contrast microscope images. A series of simulated atmospheric samples prepared from standard samples of amosite and chrysotile were observed using a phase-contrast microscope. Images were captured, and training datasets were created from the counting results of expert analysts. We adopted 2 types of AI models-an instance segmentation model, namely the mask region-based convolutional neural network (Mask R-CNN), and a semantic segmentation model, namely the multi-level aggregation network (MA-Net)-that were trained to detect asbestos fibers. The accuracy of fiber detection achieved with the Mask R-CNN model was 57% for recall and 46% for precision, whereas the accuracy achieved with the MA-Net model was 95% for recall and 91% for precision. Therefore, satisfactory results were obtained with the MA-Net model. The time required for fiber detection was less than 1 s per image in both AI models, which was faster than the time required for counting by an expert analyst.
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Intelligence artificielle , Amiante , Microscopie de contraste de phase , Microscopie de contraste de phase/méthodes , Amiante/analyse , Surveillance de l'environnement/méthodes , Humains , Japon , Atmosphère/composition chimique , , Amiante serpentine/analyseRÉSUMÉ
Drug detection in biological solutions is essential in studying the pharmacokinetics of the body. Electrochemical detection is an accurate and rapid method, but measuring multiple drugs that react at similar potentials is challenging. Herein, we developed an electrochemical sensor using a boron-doped diamond (BDD) electrode modified with a molecularly imprinted polymer (MIP) to provide specificity in drug sensing. The MIP is a polymer material designed to recognize and capture template molecules, enabling the selective detection of target molecules. In this study, we selected the anticancer drug doxorubicin (DOX) as the template molecule. In the electrochemical measurements using an unmodified BDD, the DOX reduction was observed at approximately -0.5 V (vs Ag/AgCl). Other drugs, i.e., mitomycin C or clonazepam (CZP), also underwent a reduction reaction at a similar potential to that of DOX, when using the unmodified BDD, which rendered the accurate quantification of DOX in a mixture challenging. Similar measurements conducted in PBS using the MIP-BDD only resulted in a DOX reduction current, with no reduction reaction observed in the presence of mitomycin C and CZP. These results suggest that the MIP, whose template molecule is DOX, inhibits the reduction of other drugs on the electrode surface. Selective DOX measurement using the MIP-BDD was also possible in human plasma, and the respective limits of detection of DOX in PBS and human plasma were 32.10 and 16.61 nM. The MIP-BDD was durable for use in six repeated measurements, and MIP-BDD may be applicable as an electrochemical sensor for application in therapeutic drug monitoring.
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Techniques électrochimiques , Polymères à empreintes moléculaires , Humains , Techniques électrochimiques/méthodes , Bore/composition chimique , Mitomycine , Limite de détection , Électrodes , DoxorubicineRÉSUMÉ
This corrects the article DOI: 10.1103/PhysRevLett.130.200602.
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A variety of CRISPR-Cas9-based gene editing technologies have been developed, including gene insertion and gene replacement, and applied to the study and treatment of diseases. While numerous studies have been conducted to improve the efficiency of gene insertion and to expand the system in various ways, there have been relatively few reports on gene replacement technology; therefore, further improvements are still needed in this context. Here, we developed the REMOVER-PITCh system to establish an efficient long-range gene replacement method and demonstrated its utility at two genomic loci in human cultured cells. REMOVER-PITCh depends on microhomology-assisted gene insertion technology called PITCh with highly multiplexed CRISPR-Cas9. First, we achieved gene replacement of about 20-kb GUSB locus using this system. Second, by applying the previously established knock-in-enhancing platform, the LoAD system, along with REMOVER-PITCh, we achieved the replacement of a longer gene region of about 200 kb at the ARSB locus. Our REMOVER-PITCh system will make it possible to remove and incorporate a variety of sequences from and into the genome, respectively, which will facilitate the generation of various disease and humanized models.
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Systèmes CRISPR-Cas , Édition de gène , Systèmes CRISPR-Cas/génétique , Humains , Édition de gène/méthodes , Séquence nucléotidique , Cellules HEK293RÉSUMÉ
Amplification of MYCN is observed in high-risk neuroblastomas (NBs) and is associated with a poor prognosis. MYCN expression is directly regulated by multiple transcription factors, including OCT4, MYCN, CTCF, and p53 in NB. Our previous study showed that inhibition of p53 binding at the MYCN locus induces NB cell death. However, it remains unclear whether inhibition of alternative transcription factor induces NB cell death. In this study, we revealed that the inhibition of OCT4 binding at the MYCN locus, a critical site for the human-specific OCT4-MYCN positive feedback loop, induces caspase-2-mediated cell death in MYCN-amplified NB. We used the CRISPR/deactivated Cas9 (dCas9) technology to specifically inhibit transcription factors from binding to the MYCN locus in the MYCN-amplified NB cell lines CHP134 and IMR32. In both cell lines, the inhibition of OCT4 binding at the MYCN locus reduced MYCN expression, thereby suppressing MYCN-target genes. After inhibition of OCT4 binding, differentially downregulated transcripts were associated with high-open reading frame (ORF) dominance score, which is associated with the translation efficiency of transcripts. These transcripts were enriched in splicing factors, including MYCN-target genes such as HNRNPA1 and PTBP1. Furthermore, transcripts with a high-ORF dominance score were significantly associated with genes whose high expression is associated with a poor prognosis in NB. Because the ORF dominance score correlates with the translation efficiency of transcripts, our findings suggest that MYCN maintains the expression of transcripts with high translation efficiency, contributing to a poor prognosis in NB. In conclusion, the inhibition of OCT4 binding at the MYCN locus resulted in reduced MYCN activity, which in turn led to the downregulation of high-ORF dominance transcripts and subsequently induced caspase-2-mediated cell death in MYCN-amplified NB cells. Therefore, disruption of the OCT4 binding at the MYCN locus may serve as an effective therapeutic strategy for MYCN-amplified NB.