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1.
Cell ; 177(2): 243-255.e15, 2019 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-30827682

RESUMEN

Mammals cannot see light over 700 nm in wavelength. This limitation is due to the physical thermodynamic properties of the photon-detecting opsins. However, the detection of naturally invisible near-infrared (NIR) light is a desirable ability. To break this limitation, we developed ocular injectable photoreceptor-binding upconversion nanoparticles (pbUCNPs). These nanoparticles anchored on retinal photoreceptors as miniature NIR light transducers to create NIR light image vision with negligible side effects. Based on single-photoreceptor recordings, electroretinograms, cortical recordings, and visual behavioral tests, we demonstrated that mice with these nanoantennae could not only perceive NIR light, but also see NIR light patterns. Excitingly, the injected mice were also able to differentiate sophisticated NIR shape patterns. Moreover, the NIR light pattern vision was ambient-daylight compatible and existed in parallel with native daylight vision. This new method will provide unmatched opportunities for a wide variety of emerging bio-integrated nanodevice designs and applications. VIDEO ABSTRACT.


Asunto(s)
Nanopartículas/uso terapéutico , Células Fotorreceptoras de Vertebrados/fisiología , Visión Ocular/fisiología , Animales , Femenino , Rayos Infrarrojos , Inyecciones/métodos , Luz , Masculino , Mamíferos/fisiología , Ratones , Ratones Endogámicos C57BL , Opsinas/metabolismo , Retina/metabolismo , Retina/fisiología , Células Fotorreceptoras Retinianas Conos/fisiología , Visión Ocular/genética
2.
EMBO J ; 42(1): e110937, 2023 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-36382717

RESUMEN

Hutchinson-Gilford progeria syndrome (HGPS) is a lethal premature aging disorder without an effective therapeutic regimen. Because of their targetability and influence on gene expression, microRNAs (miRNAs) are attractive therapeutic tools to treat diseases. Here we identified that hsa-miR-59 (miR-59) was markedly upregulated in HGPS patient cells and in multiple tissues of an HGPS mouse model (LmnaG609G/G609G ), which disturbed the interaction between RNAPII and TFIIH, resulting in abnormal expression of cell cycle genes by targeting high-mobility group A family HMGA1 and HMGA2. Functional inhibition of miR-59 alleviated the cellular senescence phenotype of HGPS cells. Treatment with AAV9-mediated anti-miR-59 reduced fibrosis in the quadriceps muscle, heart, and aorta, suppressed epidermal thinning and dermal fat loss, and yielded a 25.5% increase in longevity of LmnaG609G/G609G mice. These results identify a new strategy for the treatment of HGPS and provide insight into the etiology of HGPS disease.


Asunto(s)
MicroARNs , Progeria , Ratones , Animales , Progeria/genética , Antagomirs/uso terapéutico , Senescencia Celular/genética , MicroARNs/genética , Fenotipo
3.
Nucleic Acids Res ; 52(6): 2776-2791, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38366553

RESUMEN

5-Methylcytosine (m5C), an abundant RNA modification, plays a crucial role in regulating RNA fate and gene expression. While recent progress has been made in understanding the biological roles of m5C, the inability to introduce m5C at specific sites within transcripts has hindered efforts to elucidate direct links between specific m5C and phenotypic outcomes. Here, we developed a CRISPR-Cas13d-based tool, named reengineered m5C modification system (termed 'RCMS'), for targeted m5C methylation and demethylation in specific transcripts. The RCMS editors consist of a nuclear-localized dCasRx conjugated to either a methyltransferase, NSUN2/NSUN6, or a demethylase, the catalytic domain of mouse Tet2 (ten-eleven translocation 2), enabling the manipulation of methylation events at precise m5C sites. We demonstrate that the RCMS editors can direct site-specific m5C incorporation and demethylation. Furthermore, we confirm their effectiveness in modulating m5C levels within transfer RNAs and their ability to induce changes in transcript abundance and cell proliferation through m5C-mediated mechanisms. These findings collectively establish RCMS editors as a focused epitranscriptome engineering tool, facilitating the identification of individual m5C alterations and their consequential effects.


Asunto(s)
5-Metilcitosina , Técnicas Genéticas , Metilación , Metiltransferasas , Edición de ARN , Animales , Ratones , 5-Metilcitosina/metabolismo , Metiltransferasas/genética , Metiltransferasas/metabolismo , ARN de Transferencia/metabolismo , Sistemas CRISPR-Cas , Humanos
4.
Cell Mol Life Sci ; 81(1): 156, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38551746

RESUMEN

X chromosome inactivation (XCI) is a process that equalizes the expression of X-linked genes between males and females. It relies on Xist, continuously expressed in somatic cells during XCI maintenance. However, how Xist impacts XCI maintenance and its functional motifs remain unclear. In this study, we conducted a comprehensive analysis of Xist, using rabbits as an ideal non-primate model. Homozygous knockout of exon 1, exon 6, and repeat A in female rabbits resulted in embryonic lethality. However, X∆ReAX females, with intact X chromosome expressing Xist, showed no abnormalities. Interestingly, there were no significant differences between females with homozygous knockout of exons 2-5 and wild-type rabbits, suggesting that exons 2, 3, 4, and 5 are less important for XCI. These findings provide evolutionary insights into Xist function.


Asunto(s)
ARN Largo no Codificante , Inactivación del Cromosoma X , Humanos , Masculino , Animales , Conejos , Femenino , Inactivación del Cromosoma X/genética , ARN Largo no Codificante/genética , Cromosomas Humanos X , Cromosoma X/genética , Exones/genética
5.
Anal Chem ; 96(25): 10274-10282, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38860851

RESUMEN

Multiple intracellular microRNA (miRNA) detection is essential for disease diagnosis and management. Nonetheless, the real-time detection of multiple intracellular miRNAs has remained challenging. Herein, we have developed an ultrasound (US)-powered nanomotor-based dynamic fluorescent probe for the real-time OFF-ON fluorescent determination of multiple intracellular miRNAs. The new probe relies on the utilization of multicolored quantum dot (QD)-labeled single-stranded DNA (ssDNA)/graphene oxide (GO)-coated US-powered gold nanowire (AuNW) nanomotors. The fluorescence of QDs is quenched due to π-π interactions with the GO. Upon binding to target miRNAs, the QDs-ssDNA is now distant from the AuNWs, resulting in effective OFF-ON QD fluorescence switching. Compared with conventional passive probes, the dynamic fluorescent probe enhances probe-target interactions by using the US-propelled nanomotor, resulting in exceptionally efficient and prompt hybridization. Simultaneous quantitative analysis of miR-10b and miR-21 in vitro can be achieved within 15 min with high sensitivity and specificity. Additionally, multicolor QDs provide strong signal intensity and multiplexed detection, enabling one-step real-time discrimination between cancer cells (A549) and normal cells (L02). The obtained results are in good agreement with those from qRT-PCR. This dynamic fluorescent probe based on a nanomotor and QDs enables rapid "on the move" specific detection of multiple intracellular miRNAs in intact cells, facilitating real-time monitoring of diverse intracellular miRNA expression, and it could pave the way for novel applications of nanomotors in biodetection.


Asunto(s)
Colorantes Fluorescentes , Grafito , MicroARNs , Puntos Cuánticos , MicroARNs/análisis , Humanos , Colorantes Fluorescentes/química , Puntos Cuánticos/química , Grafito/química , Oro/química , ADN de Cadena Simple/química , Nanocables/química , Ondas Ultrasónicas , Células A549
6.
Chemistry ; : e202401011, 2024 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-38757219

RESUMEN

The room temperature metal-free cascade electrophilic addition/cyclization/oxidation reactions of (3-phenoxyprop-1-yn-1-yl)benzenes to divergently synthesize various brominated benzopyran derivatives (3-bromo-2H-chromenes, 3-bromo-2H-chromen-2-ols and 3-bromo coumarins) by tuning the amount of Br2 and H2O have been developed. The method exhibited high selectivity, mild reaction conditions, broad substrate scope, high efficiency, and the applicability for derivatization of the brominated products. The importance of the strategies provides a great advantage for selective synthesis of brominated benzopyran derivatives.

7.
J Org Chem ; 89(6): 3809-3820, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38395778

RESUMEN

The La(OTf)3-catalyzed [3+2] cycloaddition reactions for the synthesis of benzo[d]oxazoles/benzofurans via quinones and 1,2-di-tert-butyl-3-(cyanimino)diaziridine (1,3-di-tert-butyl-2-cyanoguanidine)/vinyl azides have been explored. A series of 5-hydroxybenzofuran-4-carboxylic acid derivatives and 5-hydroxybenzo[d]oxazole-4-carboxylic acid derivatives were conveniently obtained with high yields and good stereoselectivities, which could be used for further transformations to valuable compounds.

8.
Arterioscler Thromb Vasc Biol ; 43(1): e11-e28, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36412196

RESUMEN

BACKGROUND: Elevated plasma Lp-PLA2 (lipoprotein-associated phospholipase A2) activity is closely associated with an increased risk of cardiovascular events. However, whether and how Lp-PLA2 is directly involved in the pathogenesis of atherosclerosis is still unclear. To examine the hypothesis that Lp-PLA2 could be a potential preventative target of atherosclerosis, we generated Lp-PLA2 knockout rabbits and investigated the pathophysiological functions of Lp-PLA2. METHODS: Lp-PLA2 knockout rabbits were generated using CRISPR/Cas9 system to assess the role of Lp-PLA2 in plasma lipids regulation and identify its underlying molecular mechanisms. Homozygous knockout rabbits along with wild-type rabbits were fed a cholesterol-rich diet for up to 14 weeks and their atherosclerotic lesions were compared. Moreover, the effects of Lp-PLA2 deficiency on the key cellular behaviors in atherosclerosis were assessed in vitro. RESULTS: When rabbits were fed a standard diet, Lp-PLA2 deficiency led to a significant reduction in plasma lipids. The decreased protein levels of SREBP2 (sterol regulatory element-binding protein 2) and HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) in livers of homozygous knockout rabbits indicated that the cholesterol biosynthetic pathway was impaired with Lp-PLA2 deficiency. In vitro experiments further demonstrated that intracellular Lp-PLA2 efficiently enhanced SREBP2-related cholesterol biosynthesis signaling independently of INSIGs (insulin-induced genes). When fed a cholesterol-rich diet, homozygous knockout rabbits exhibited consistently lower level of hypercholesterolemia, and their aortic atherosclerosis lesions were significantly reduced by 60.2% compared with those of wild-type rabbits. The lesions of homozygous knockout rabbits were characterized by reduced macrophages and the expression of inflammatory cytokines. Macrophages of homozygous knockout rabbits were insensitive to M1 polarization and showed reduced DiI-labeled lipoprotein uptake capacity compared with wild-type macrophages. Lp-PLA2 deficiency also inhibited the adhesion between monocytes and endothelial cells. CONCLUSIONS: These results demonstrate that Lp-PLA2 plays a causal role in regulating blood lipid homeostasis and Lp-PLA2 deficiency protects against dietary cholesterol-induced atherosclerosis in rabbits. Lp-PLA2 could be a potential target for the prevention of atherosclerosis.


Asunto(s)
Aterosclerosis , Hiperlipidemias , Animales , Conejos , 1-Alquil-2-acetilglicerofosfocolina Esterasa/genética , Lipoproteína(a) , Fosfolipasas , Células Endoteliales/metabolismo , Aterosclerosis/genética , Aterosclerosis/prevención & control , Lípidos , Colesterol
9.
Cell Mol Life Sci ; 80(11): 346, 2023 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-37924393

RESUMEN

The recently developed prime-editing (PE) technique is more precise than previously available techniques and permits base-to-base conversion, replacement, and insertions and deletions in the genome. However, previous reports show that the efficiency of prime editing is insufficient to produce genome-edited animals. In fact, prime-guide RNA (pegRNA) designs have posed a challenge in achieving favorable editing efficiency. Here, we designed prime binding sites (PBS) with a melting temperature (Tm) of 42 °C, leading to optimal performance in cells, and we found that the optimal Tm was affected by the culture temperature. In addition, the ePE3max system was developed by updating the PE architecture to PEmax and expressing engineered pegRNA (epegRNA) based on the original PE3 system. The updated ePE3max system can efficiently induce gene editing in mouse and rabbit embryos. Furthermore, we successfully generated a Hoxd13 (c. 671 G > T) mutation in mice and a Tyr (c. 572 del) mutation in rabbits by ePE3max. Overall, the editing efficiency of modified ePE3max systems is superior to that of the original PE3 system in producing genome-edited animals, which can serve as an effective and versatile genome-editing tool for precise genome modification in animal models.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Conejos , Animales , Ratones , Sitios de Unión , Modelos Animales , Mutación , Temperatura , Sistemas CRISPR-Cas/genética
10.
BMC Biol ; 21(1): 155, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37434184

RESUMEN

BACKGROUND: Adenine base editors (ABEs) are promising therapeutic gene editing tools that can efficiently convert targeted A•T to G•C base pairs in the genome. However, the large size of commonly used ABEs based on SpCas9 hinders its delivery in vivo using certain vectors such as adeno-associated virus (AAV) during preclinical applications. Despite a number of approaches having previously been attempted to overcome that challenge, including split Cas9-derived and numerous domain-deleted versions of editors, whether base editor (BE) and prime editor (PE) systems can also allow deletion of those domains remains to be proven. In this study, we present a new small ABE (sABE) with significantly reduced size. RESULTS: We discovered that ABE8e can tolerate large single deletions in the REC2 (Δ174-296) and HNH (Δ786-855) domains of SpCas9, and these deletions can be stacked together to create a new sABE. The sABE showed higher precision than the original ABE8e, with proximally shifted protospacer adjacent motif (PAM) editing windows (A3- A15), and comparable editing efficiencies to 8e-SaCas9-KKH. The sABE system efficiently generated A-G mutations at disease-relevant loci (T1214C in GAA and A494G in MFN2) in HEK293T cells and several canonical Pcsk9 splice sites in N2a cells. Moreover, the sABE enabled in vivo delivery in a single adeno-associated virus (AAV) vector with slight efficiency. Furthermore, we also successfully edited the genome of mouse embryos by microinjecting mRNA and sgRNA of sABE system into zygotes. CONCLUSIONS: We have developed a substantially smaller sABE system that expands the targeting scope and offers higher precision of genome editing. Our findings suggest that the sABE system holds great therapeutic potential in preclinical applications.


Asunto(s)
Edición Génica , Proproteína Convertasa 9 , ARN Guía de Sistemas CRISPR-Cas , Animales , Humanos , Ratones , Adenina , Células HEK293
11.
BMC Biol ; 21(1): 250, 2023 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-37946200

RESUMEN

BACKGROUND: Nme2ABE8e has been constructed and characterized as a compact, accurate adenine base editor with a less restrictive dinucleotide protospacer-adjacent motif (PAM: N4CC) but low editing efficiency at challenging loci in human cells. Here, we engineered a subset of domain-inlaid Nme2Cas9 base editors to bring the deaminase domain closer to the nontarget strand to improve editing efficiency. RESULTS: Our results demonstrated that Nme2ABE8e-797 with adenine deaminase inserted between amino acids 797 and 798 has a significantly increased editing efficiency with a wide editing window ranging from 4 to 18 bases in mammalian cells, especially at the sites that were difficult to edit by Nme2ABE8e. In addition, by swapping the PAM-interacting domain of Nme2ABE8e-797 with that of SmuCas9 or introducing point mutations of eNme2-C in Nme2ABE8e-797, we created Nme2ABE8e-797Smu and Nme2ABE8e-797-C, respectively, which exhibited robust activities at a wide range of sites with N4CN PAMs in human cells. Moreover, the modified domain-inlaid Nme2ABE8e can efficiently restore or install disease-related loci in Neuro-2a cells and mice. CONCLUSIONS: These novel Nme2ABE8es with increased on-target DNA editing and expanded PAM compatibility will expand the base editing toolset for efficient gene modification and therapeutic applications.


Asunto(s)
Proteína 9 Asociada a CRISPR , Sistemas CRISPR-Cas , Animales , Humanos , Ratones , Proteína 9 Asociada a CRISPR/genética , Adenina/química , Edición Génica/métodos , ADN/genética , Mamíferos/genética
12.
Neurobiol Dis ; 182: 106135, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37142085

RESUMEN

Primary microcephaly (PMCPH) is a rare autosomal recessive neurodevelopmental disorder with a global prevalence of PMCPH ranging from 0.0013% to 0.15%. Recently, a homozygous missense mutation in YIPF5 (p.W218R) was identified as a causative mutation of severe microcephaly. In this study, we constructed a rabbit PMCPH model harboring YIPF5 (p.W218R) mutation using SpRY-ABEmax mediated base substitution, which precisely recapitulated the typical symptoms of human PMCPH. Compared with wild-type controls, the mutant rabbits exhibited stunted growth, reduced head circumference, altered motor ability, and decreased survival rates. Further investigation based on model rabbit elucidated that altered YIPF5 function in cortical neurons could lead to endoplasmic reticulum stress and neurodevelopmental disorders, interference of the generation of apical progenitors (APs), the first generation of progenitors in the developing cortex. Furthermore, these YIPF5-mutant rabbits support a correlation between unfolded protein responses (UPR) induced by endoplasmic reticulum stress (ERS), and the development of PMCPH, thus providing a new perspective on the role of YIPF5 in human brain development and a theoretical basis for the differential diagnosis and clinical treatment of PMCPH. To our knowledge, this is the first gene-edited rabbit model of PMCPH. The model better mimics the clinical features of human microcephaly than the traditional mouse models. Hence, it provides great potential for understanding the pathogenesis and developing novel diagnostic and therapeutic approaches for PMCPH.


Asunto(s)
Microcefalia , Ratones , Animales , Humanos , Conejos , Microcefalia/genética , Microcefalia/patología , Mutación/genética , Mutación Missense , Respuesta de Proteína Desplegada/genética , Estrés del Retículo Endoplásmico/genética , Proteínas de Transporte Vesicular/genética
13.
Mol Ther ; 30(1): 256-267, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34174445

RESUMEN

Compact CRISPR-Cas9 systems that can be packaged into an adeno-associated virus (AAV) show promise for gene therapy. However, the requirement of protospacer adjacent motifs (PAMs) restricts the target scope. To expand this repertoire, we revisited and optimized a small Cas9 ortholog derived from Streptococcus pasteurianus (SpaCas9) for efficient genome editing in vivo. We found that SpaCas9 enables potent targeting of 5'-NNGYRA-3' PAMs, which are distinct from those recognized by currently used small Cas9s; the Spa-cytosine base editor (CBE) and Spa-adenine base editor (ABE) systems efficiently generated robust C-to-T and A-to-G conversions both in vitro and in vivo. In addition, by exploiting natural variation in the PAM-interacting domain, we engineered three SpaCas9 variants to further expand the targeting scope of compact Cas9 systems. Moreover, mutant mice with efficient disruption of the Tyr gene were successfully generated by microinjection of SpaCas9 mRNA and the corresponding single guide RNA (sgRNA) into zygotes. Notably, all-in-one AAV delivery of SpaCas9 targeting the Pcsk9 gene in adult mouse liver produced efficient genome-editing events and reduced its serum cholesterol. Thus, with distinct PAMs and a small size, SpaCas9 will broaden the CRISPR-Cas9 toolsets for efficient gene modifications and therapeutic applications.


Asunto(s)
Edición Génica , Proproteína Convertasa 9 , Animales , Proteína 9 Asociada a CRISPR/genética , Proteína 9 Asociada a CRISPR/metabolismo , Sistemas CRISPR-Cas , Ratones , Proproteína Convertasa 9/genética , ARN Guía de Kinetoplastida/genética , Streptococcus
14.
Chemistry ; 28(26): e202104366, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35218098

RESUMEN

While concerns about improving recharged afterglow intensity in vivo still motivate further exploration, afterglow nanoparticles (AGNP) offer unique optical merit for autofluorescence-free biological imaging. Apart from efforts enhancing the afterglow emission properties of AGNP, improving afterglow excitation response to visible or near infrared light is important but has lacked success. Dye sensitization has been used to improve the optical response of photovoltaic nanomaterials and to enhance upconversion luminescence efficiency. This concept has recently been expanded and applied to AGNPs. As a new multifunctional nanoprobe, such dye-sensitized AGNP takes advantage of both high spatial resolution fluorescence imaging and sensitive afterglow imaging. This Concept introduces the background, the concept, mechanism, and related imaging application, as well as reviewing existing challenges and proposing future developmental directions for the dye-sensitized AGNPs.


Asunto(s)
Luminiscencia , Nanopartículas , Rayos Infrarrojos , Imagen Óptica/métodos
15.
J Org Chem ; 87(19): 12721-12732, 2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36099272

RESUMEN

Two concise strategies to synthesize oxazolidin-2-imines by cascade nucleophilic attack/addition cyclization reactions of (Z)-2-bromo-3-phenylprop-2-en-1-ols/3-phenylprop-2-yn-1-ols and diphenyl carbodiimides without a transition-metal catalyst have been developed. The reactions exhibited good substrate applicability tolerance, and a variety of substituted (Z)-4-((Z)-benzylidene)-N,3-diphenyloxazolidin-2-imines were synthesized in moderate to excellent yields with good stereoselectivity. The reports also provided a convenient strategy to synthesize 3-phenylprop-2-yn-1-ols by (Z)-2-bromo-3-phenylprop-2-en-1-ols. The economic and practical methods provide a great advantage for potential industrial synthesis of oxazolidin-2-imines.


Asunto(s)
Carbodiimidas , Iminas , Compuestos de Bifenilo , Ciclización , Estructura Molecular , Propanoles
16.
Nano Lett ; 21(12): 4903-4910, 2021 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-34100617

RESUMEN

Persistent luminescence nanoparticles (PLNPs) are an emerging photonic nanomaterial that possesses uniquely persistent luminescence properties after excitation ceases. They can be repeatedly recharged in vitro and in vivo and hold great promise for numerous areas and applications. Unfortunately, none of the existing synthesis methods can control their composition to grow core-shell structured PLNPs with desirable shapes and enhanced functionalities. Here, we report on straightforward thermolysis-mediated colloidal synthesis of CaF2:Dy@NaYF4 core-shell PLNPs that can enhance persistent luminescence under both light and X-ray excitations. Benefitting from the well-matched crystal lattices between CaF2 and NaYF4, this colloidal synthesis makes it possible to prepare core-shell PLNPs with exquisite control of the compositions, shapes, and enhanced luminescence. This demonstration of the developing colloidal core-shell PLNPs overcomes the current key bottleneck regarding the synthesis of heterostructured PLNPs and sets the stage for fully exploiting the potential of these fascinating luminous materials.


Asunto(s)
Nanopartículas , Nanoestructuras , Luminiscencia
17.
Molecules ; 27(21)2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36364217

RESUMEN

The efficient "One-pot" CuCl2-catalyzed C-S bond coupling reactions were developed for the synthesis of dibenzo[b,f][1,4]thiazepines and 11-methy-ldibenzo[b,f][1,4]thiazepines via 2-iodobenzaldehydes/2-iodoacetophenones with 2-aminobenzenethiols/2,2'-disulfanediyldianilines by using bifunctional-reagent N, N'-dimethylethane-1,2-diamine (DMEDA), which worked as ligand and reductant. The reactions were compatible with a range of substrates to give the corresponding products in moderate to excellent yields.


Asunto(s)
Diaminas , Tiazepinas , Catálisis , Indicadores y Reactivos , Dibenzotiazepinas
18.
FASEB J ; 34(1): 588-596, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31914687

RESUMEN

Base editors, composed of a cytidine deaminase or an evolved adenine deaminase fused to Cas9 nickase, enable efficient C-to-T or A-to-G conversion in various organisms. However, the NGG protospacer adjacent motif (PAM) requirement of Streptococcus pyogenes Cas9 (SpCas9) substantially limits the target sites suitable for base editing. Quite recently, a new engineered SpCas9-NG variant, which can recognize minimal NG PAMs more efficiently than the present xCas9 variant. Here, we investigated the efficiency and PAM compatibility of SpCas9-NG-assisted cytidine base editors (CBEs) and adenine base editors (ABEs) in rabbits. In this study, we showed that NG-BE4max and NG-ABEmax systems can achieve a targeted mutation efficiency of 75%-100% and 80%-100% with excellent PAM compatibility of NGN PAMs in rabbit embryos, respectively. In addition, both base editors were successfully applied to create new rabbit models with precise point mutations, demonstrating their high efficiency and expanded genome-targeting scope in rabbits. Meanwhile, NG-ABEmax can be used to precisely mimic human Hoxc13 p.Q271R missense mutation in Founder (F0) rabbits, which is arduous for conventional ABEs to achieve due to a NGA PAM requirement. Collectively, NG-BE4max and NG-ABEmax systems provide promising tools to perform efficient base editing with expanded targeting scope in rabbits and enhances its capacity to model human diseases.


Asunto(s)
Proteína 9 Asociada a CRISPR/genética , Sistemas CRISPR-Cas , Embrión de Mamíferos/metabolismo , Edición Génica/métodos , Mutación , Motivos de Nucleótidos/genética , Adenina/química , Animales , Citosina/química , Embrión de Mamíferos/citología , Factor 5 de Crecimiento de Fibroblastos/genética , Proteínas de Homeodominio/genética , Modelos Animales , Conejos , Streptococcus pyogenes/genética
19.
Cell Mol Life Sci ; 77(16): 3265-3277, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31720743

RESUMEN

Glucokinase (GCK) is a key enzyme in glucose sensing and glycemic regulation. In humans, mutations in the GCK gene cause maturity-onset diabetes of the young 2 (MODY-2), a disease that is characterized by an early-onset and persistent hyperglycemia. It is known that Gck knockout (KO) is lethal in mice with Gck KO mice dying within 2 weeks after birth. Therefore, Gck KO mice are not suitable for preclinical study and have limited suitability to study the pathophysiological role of glucokinase in vivo. Here, we report the generation of a novel rabbit with a non-frameshift mutation of GCK gene (GCK-NFS) by cytoplasm microinjection of Cas9 mRNA and gRNA. These GCK-NFS rabbits showed typical features of MODY-2 including hyperglycemia and glucose intolerance with similar survival rate and weight compared to wild-type (WT) rabbits. The diabetic phenotype including pancreatic and renal dysfunction was also found in the F1-generation rabbits, indicating that the genetic modification is germline transmissible. Treatment of GCK-NFS rabbit with glimepiride successfully reduced the fasting blood glucose drastically and improved its islet function. In conclusion, this novel GCK mutant rabbit generated with the CRISPR/Cas9 system mimics most, if not all, histopathological and functional defects seen in MODY-2 patients such as hyperglycemia and will be a valuable rabbit model for preclinical studies and drug screening for diabetes as well as for studying the pathophysiological role of glucokinase.


Asunto(s)
Sistemas CRISPR-Cas/genética , Diabetes Mellitus Tipo 2/genética , Glucoquinasa/genética , Hiperglucemia/genética , Animales , Glucemia/genética , Eliminación de Gen , Humanos , Ratones , Ratones Noqueados , Mutación/genética , Fenotipo , Conejos
20.
Cell Mol Life Sci ; 77(4): 719-733, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31302752

RESUMEN

Cytidine base editors (CBEs) have been demonstrated to be useful for precisely inducing C:G-to-T:A base mutations in various organisms. In this study, we showed that the BE4-Gam system induced the targeted C-to-T base conversion in porcine blastocysts at an efficiency of 66.7-71.4% via the injection of a single sgRNA targeting a xeno-antigen-related gene and BE4-Gam mRNA. Furthermore, the efficiency of simultaneous three gene base conversion via the injection of three targeting sgRNAs and BE4-Gam mRNA into porcine parthenogenetic embryos was 18.1%. We also obtained beta-1,4-N-acetyl-galactosaminyl transferase 2, alpha-1,3-galactosyltransferase, and cytidine monophosphate-N-acetylneuraminic acid hydroxylase deficient pig by somatic cell nuclear transfer, which exhibited significantly decreased activity. In addition, a new CBE version (termed AncBE4max) was used to edit genes in blastocysts and porcine fibroblasts (PFFs) for the first time. While this new version demonstrated a three genes base-editing rate of 71.4% at the porcine GGTA1, B4galNT2, and CMAH loci, it increased the frequency of bystander edits, which ranged from 17.8 to 71.4%. In this study, we efficiently and precisely mutated bases in porcine blastocysts and PFFs using CBEs and successfully generated C-to-T and C-to-G mutations in pigs. These results suggest that CBEs provide a more simple and efficient method for improving economic traits, reducing the breeding cycle, and increasing disease tolerance in pigs, thus aiding in the development of human disease models.


Asunto(s)
Citidina/genética , Edición Génica/métodos , Porcinos/genética , Animales , Blastocisto/metabolismo , Sistemas CRISPR-Cas , Galactosiltransferasas/genética , Vectores Genéticos/genética , Oxigenasas de Función Mixta/genética , Mutagénesis , N-Acetilgalactosaminiltransferasas/genética , ARN Guía de Kinetoplastida/genética , Porcinos/embriología
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