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1.
Nat Commun ; 11(1): 4468, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901021

RESUMO

Speciation constrains the flow of genetic information between populations of sexually reproducing organisms. Gaining control over mechanisms of speciation would enable new strategies to manage wild populations of disease vectors, agricultural pests, and invasive species. Additionally, such control would provide safe biocontainment of transgenes and gene drives. Here, we demonstrate a general approach to create engineered genetic incompatibilities (EGIs) in the model insect Drosophila melanogaster. EGI couples a dominant lethal transgene with a recessive resistance allele. Strains homozygous for both elements are fertile and fecund when they mate with similarly engineered strains, but incompatible with wild-type strains that lack resistant alleles. EGI genotypes can also be tuned to cause hybrid lethality at different developmental life-stages. Further, we demonstrate that multiple orthogonal EGI strains of D. melanogaster can be engineered to be mutually incompatible with wild-type and with each other. EGI is a simple and robust approach in multiple sexually reproducing organisms.


Assuntos
Drosophila melanogaster/genética , Engenharia Genética/métodos , Especiação Genética , Animais , Animais Geneticamente Modificados , Cruzamentos Genéticos , Feminino , Genes de Insetos , Genes Letais , Genótipo , Hibridização Genética , Masculino , Modelos Genéticos , Transgenes
2.
Nat Commun ; 11(1): 4903, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994412

RESUMO

The CRISPR-Cas9 system has increased the speed and precision of genetic editing in cells and animals. However, model generation for drug development is still expensive and time-consuming, demanding more target flexibility and faster turnaround times with high reproducibility. The generation of a tightly controlled ObLiGaRe doxycycline inducible SpCas9 (ODInCas9) transgene and its use in targeted ObLiGaRe results in functional integration into both human and mouse cells culminating in the generation of the ODInCas9 mouse. Genomic editing can be performed in cells of various tissue origins without any detectable gene editing in the absence of doxycycline. Somatic in vivo editing can model non-small cell lung cancer (NSCLC) adenocarcinomas, enabling treatment studies to validate the efficacy of candidate drugs. The ODInCas9 mouse allows robust and tunable genome editing granting flexibility, speed and uniformity at less cost, leading to high throughput and practical preclinical in vivo therapeutic testing.


Assuntos
Sistemas CRISPR-Cas/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Descoberta de Drogas/métodos , Edição de Genes/métodos , Neoplasias Pulmonares/tratamento farmacológico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proteína 9 Associada à CRISPR/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Doxiciclina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Feminino , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Vetores Genéticos/genética , Células HEK293 , Ensaios de Triagem em Larga Escala/métodos , Humanos , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Transgênicos , RNA Guia/genética , Recombinação Genética/efeitos dos fármacos , Reprodutibilidade dos Testes , Ativação Transcricional/efeitos dos fármacos , Transfecção/métodos , Transgenes/genética
4.
PLoS One ; 15(8): e0235691, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857763

RESUMO

Exercise exerts a beneficial effect on the major pathological and clinical symptoms associated with Alzheimer's disease in humans and mouse models of the disease. While numerous mechanisms for such benefits from exercise have been proposed, a clear understanding of the causal links remains elusive. Recent studies also suggest that cerebral blood flow in the brain of both Alzheimer's patients and mouse models of the disease is decreased and that the cognitive symptoms can be improved when blood flow is restored. We therefore hypothesized that the mitigating effect of exercise on the development and progression of Alzheimer's disease may be mediated through an increase in the otherwise reduced brain blood flow. To test this idea, we performed a pilot study to examine the impact of three months of voluntary wheel running in a small cohort of ~1-year-old APP/PS1 mice on short-term memory function, brain inflammation, amyloid deposition, and baseline cerebral blood flow. Our findings that exercise led to a trend toward improved spatial short-term memory, reduced brain inflammation, markedly increased neurogenesis in the dentate gyrus, and a reduction in hippocampal amyloid-beta deposits are consistent with other reports on the impact of exercise on the progression of Alzheimer's related symptoms in mouse models. Notably, we did not observe any impact of wheel running on overall baseline blood flow nor on the incidence of non-flowing capillaries, a mechanism we recently identified as one contributing factor to cerebral blood flow deficits in mouse models of Alzheimer's disease. Overall, our findings add to the emerging picture of differential effects of exercise on cognition and blood flow in Alzheimer's disease pathology by showing that capillary stalling is not decreased following exercise.


Assuntos
Doença de Alzheimer/fisiopatologia , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/irrigação sanguínea , Terapia por Exercício , Presenilina-1/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/terapia , Precursor de Proteína beta-Amiloide/genética , Animais , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Circulação Cerebrovascular , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Mutação , Neurogênese , Condicionamento Físico Animal , Projetos Piloto , Presenilina-1/genética , Transgenes
5.
PLoS Biol ; 18(8): e3000851, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32822389

RESUMO

High levels of the amyloid-beta (Aß) peptide have been shown to disrupt neuronal function and induce hyperexcitability, but it is unclear what effects Aß-associated hyperexcitability may have on tauopathy pathogenesis or propagation in vivo. Using a novel transgenic mouse line to model the impact of human APP (hAPP)/Aß accumulation on tauopathy in the entorhinal cortex-hippocampal (EC-HIPP) network, we demonstrate that hAPP overexpression aggravates EC-Tau aggregation and accelerates pathological tau spread into the hippocampus. In vivo recordings revealed a strong role for hAPP/Aß, but not tau, in the emergence of EC neuronal hyperactivity and impaired theta rhythmicity. Chronic chemogenetic attenuation of EC neuronal hyperactivity led to reduced hAPP/Aß accumulation and reduced pathological tau spread into downstream hippocampus. These data strongly support the hypothesis that in Alzheimer's disease (AD), Aß-associated hyperactivity accelerates the progression of pathological tau along vulnerable neuronal circuits, and demonstrates the utility of chronic, neuromodulatory approaches in ameliorating AD pathology in vivo.


Assuntos
Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Córtex Entorrinal/metabolismo , Tauopatias/genética , Proteínas tau/genética , Potenciais de Ação/fisiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/terapia , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Dependovirus/genética , Dependovirus/metabolismo , Modelos Animais de Doenças , Eletrodos Implantados , Córtex Entorrinal/patologia , Feminino , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Neurônios/patologia , Agregados Proteicos , Técnicas Estereotáxicas , Tauopatias/metabolismo , Tauopatias/patologia , Tauopatias/terapia , Ritmo Teta/fisiologia , Transdução Genética , Transgenes , Proteínas tau/metabolismo
6.
PLoS One ; 15(7): e0232915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32706785

RESUMO

Chimeric antigen receptor (CAR) T cell therapy is an effective treatment for B cell malignancies, with emerging potential for the treatment of other hematologic cancers and solid tumors. The strength of the promoter within the CAR cassette will alter CAR-polypeptide levels on the cell surface of the T cell-impacting on the kinetics of activation, survival and memory cell formation in T cells. In addition to the CAR, promoters can be used to drive other genes of interest to enhance CAR T cell function. Expressing multiple genes from a single RNA transcript can be effectively achieved by linking the genes via a ribosomal skip site. However, promoters may differ in their ability to transcribe longer RNAs, or could interfere with lentiviral production, or transduction frequencies. In this study we compared the ability of the strong well-characterized promoters CMV, EF-1, hPGK and RPBSA to drive functional expression of a single RNA encoding three products: GFP, CAR, plus an additional cell-survival gene, Mcl-1. Although the four promoters produced similarly high lentiviral titres, EF-1 gave the best transduction efficacy of primary T cells. Major differences were found in the ability of the promoters to drive expression of long RNA encoding GFP, CAR and Mcl-1, highlighting promoter choice as an important consideration for gene therapy applications requiring the expression of long and complex mRNA.


Assuntos
Engenharia Genética/métodos , Regiões Promotoras Genéticas/genética , Receptores de Antígenos Quiméricos/genética , Linfócitos T/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Lentivirus/genética , Células MCF-7 , RNA Mensageiro/genética , Transgenes/genética
7.
Nat Chem Biol ; 16(7): 766-775, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32483376

RESUMO

Cell surfaces are glycosylated in various ways with high heterogeneity, which usually leads to ambiguous conclusions about glycan-involved biological functions. Here, we describe a two-step chemoenzymatic approach for N-glycan-subtype-selective editing on the surface of living cells that consists of a first 'delete' step to remove heterogeneous N-glycoforms of a certain subclass and a second 'insert' step to assemble a well-defined N-glycan back onto the pretreated glyco-sites. Such glyco-edited cells, carrying more homogeneous oligosaccharide structures, could enable precise understanding of carbohydrate-mediated functions. In particular, N-glycan-subtype-selective remodeling and imaging with different monosaccharide motifs at the non-reducing end were successfully achieved. Using a combination of the expression system of the Lec4 CHO cell line and this two-step glycan-editing approach, opioid receptor delta 1 (OPRD1) was investigated to correlate its glycostructures with the biological functions of receptor dimerization, agonist-induced signaling and internalization.


Assuntos
Membrana Celular/química , Células Epiteliais/química , Glicoconjugados/química , Oligossacarídeos/química , Receptores Opioides delta/química , Animais , Células CHO , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Colforsina/farmacologia , Cricetulus , Encefalina Leucina/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Expressão Gênica , Glicoconjugados/metabolismo , Glicosilação , Células HEK293 , Humanos , Camundongos , Oligossacarídeos/metabolismo , Multimerização Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Receptores Opioides delta/genética , Receptores Opioides delta/metabolismo , Transgenes
8.
J Vis Exp ; (159)2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32478741

RESUMO

In this article, we give hands-on instructions to obtain translatome data from different Arabidopsis thaliana root cell types via the translating ribosome affinity purification (TRAP) method and consecutive optimized low-input library preparation. As starting material, we employ plant lines that express GFP-tagged ribosomal protein RPL18 in a cell type-specific manner by use of adequate promoters. Prior to immunopurification and RNA extraction, the tissue is snap frozen, which preserves tissue integrity and simultaneously allows execution of time series studies with high temporal resolution. Notably, cell wall structures remain intact, which is a major drawback in alternative procedures such as fluorescence-activated cell sorting-based approaches that rely on tissue protoplasting to isolate distinct cell populations. Additionally, no tissue fixation is necessary as in laser capture microdissection-based techniques, which allows high-quality RNA to be obtained. However, sampling from subpopulations of cells and only isolating polysome-associated RNA severely limits RNA yields. It is, therefore, necessary to apply sufficiently sensitive library preparation methods for successful data acquisition by RNA-seq. TRAP offers an ideal tool for plant research as many developmental processes involve cell wall-related and mechanical signaling pathways. The use of promoters to target specific cell populations is bridging the gap between organ and single-cell level that in turn suffer from little resolution or very high costs. Here, we apply TRAP to study cell-cell communication in lateral root formation.


Assuntos
Arabidopsis/metabolismo , Cromatografia de Afinidade/métodos , Raízes de Plantas/metabolismo , Biossíntese de Proteínas , Ribossomos/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Biblioteca Gênica , Proteínas de Fluorescência Verde/metabolismo , Plantas Geneticamente Modificadas , Polirribossomos/genética , RNA Mensageiro/genética , RNA de Plantas/metabolismo , Ribossomos/genética , Esterilização , Transgenes
9.
PLoS One ; 15(6): e0233784, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32492024

RESUMO

Recent advances in somatic cell nuclear transfer (SCNT) in canines facilitate the production of canine transgenic models. Owing to the importance of stable and strong promoter activity in transgenic animals, we tested human elongation factor 1α (hEF1α) and cytomegalovirus (CMV) promoter sequences in SCNT transgenic dogs. After transfection, transgenic donor fibroblasts with the hEF1α-enhanced green fluorescence protein (EGFP) transgene were successfully isolated using fluorescence-activated cell sorting (FACS). We obtained four puppies, after SCNT, and identified three puppies as being transgenic using PCR analysis. Unexpectedly, EGFP regulated by hEF1α promoter was not observed at the organismal and cellular levels in these transgenic dogs. EGFP expression was rescued by the inhibition of DNA methyltransferases, implying that the hEF1α promoter is silenced by DNA methylation. Next, donor cells with CMV-EGFP transgene were successfully established and SCNT was performed. Three puppies of six born puppies were confirmed to be transgenic. Unlike hEF1α-regulated EGFP, CMV-regulated EGFP was strongly detectable at both the organismal and cellular levels in all transgenic dogs, even after 19 months. In conclusion, our study suggests that the CMV promoter is more suitable, than the hEF1α promoter, for stable transgene expression in SCNT-derived transgenic canine model.


Assuntos
Clonagem de Organismos/veterinária , Citomegalovirus/genética , Técnicas de Transferência Nuclear/veterinária , Fator 1 de Elongação de Peptídeos/genética , Regiões Promotoras Genéticas/genética , Ativação Transcricional/genética , Animais , Animais Geneticamente Modificados , Azacitidina/farmacologia , Células Cultivadas , DNA (Citosina-5-)-Metiltransferases/antagonistas & inibidores , Metilação de DNA/efeitos dos fármacos , Cães , Transferência Embrionária/veterinária , Feminino , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/genética , Humanos , Gravidez , Transfecção , Transgenes
10.
Anticancer Res ; 40(5): 2687-2694, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32366413

RESUMO

BACKGROUND/AIM: Transforming growth factor-ß (TGF-ß) plays dual suppressive and oncogenic roles in mammary carcinogenesis. MATERIALS AND METHODS: To analyze whether TGF-ß exerts suppressive or oncogenic actions on mammary carcinogenesis, transgenic mice overexpressing a dominant-negative mutant type II TGF-ß receptor (TßRII-DNR) driven by the mouse mammary tumor virus (MMTV) promoter were treated with a low dose of urethane, a carcinogen present in fermented food products and alcoholic beverages. RESULTS: Lobular proliferative lesions, showing high ß-casein expression, developed in the mammary glands of TßRII-DNR+/+ mice aged >61 weeks. Compared with wild-type mice, TßRII-DNR+/+ mice administered with urethane showed significant increases in dysplastic hyperplasias and adenocarcinomas of the mammary glands. CONCLUSION: The functional decline of TGF-ß signaling in mammary glands led to a high susceptibility to urethane-induced mammary carcinogenesis. TGF-ß signaling may act as a tumor suppressor during mammary tumor development.


Assuntos
Carcinogênese/patologia , Genes Dominantes , Neoplasias Mamárias Animais/genética , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Neoplasias Pulmonares/patologia , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Animais/induzido quimicamente , Neoplasias Mamárias Animais/patologia , Camundongos Transgênicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II , Transgenes , Uretana
11.
Nat Commun ; 11(1): 2417, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415060

RESUMO

Striated muscle contraction is regulated by the translocation of troponin-tropomyosin strands over the thin filament surface. Relaxation relies partly on highly-favorable, conformation-dependent electrostatic contacts between actin and tropomyosin, which position tropomyosin such that it impedes actomyosin associations. Impaired relaxation and hypercontractile properties are hallmarks of various muscle disorders. The α-cardiac actin M305L hypertrophic cardiomyopathy-causing mutation lies near residues that help confine tropomyosin to an inhibitory position along thin filaments. Here, we investigate M305L actin in vivo, in vitro, and in silico to resolve emergent pathological properties and disease mechanisms. Our data suggest the mutation reduces actin flexibility and distorts the actin-tropomyosin electrostatic energy landscape that, in muscle, result in aberrant contractile inhibition and excessive force. Thus, actin flexibility may be required to establish and maintain interfacial contacts with tropomyosin as well as facilitate its movement over distinct actin surface features and is, therefore, likely necessary for proper regulation of contraction.


Assuntos
Citoesqueleto de Actina/metabolismo , Actinas/química , Doenças Musculares/patologia , Animais , Animais Geneticamente Modificados , Cardiomiopatia Hipertrófica , Biologia Computacional , Drosophila melanogaster/metabolismo , Feminino , Voo Animal , Humanos , Ligação de Hidrogênio , Masculino , Microscopia de Fluorescência , Simulação de Dinâmica Molecular , Contração Muscular , Mutação , Análise de Componente Principal , Multimerização Proteica , Eletricidade Estática , Transgenes , Tropomiosina/química
12.
Science ; 368(6494): 993-1001, 2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32467389

RESUMO

Sophisticated devices for remote-controlled medical interventions require an electrogenetic interface that uses digital electronic input to directly program cellular behavior. We present a cofactor-free bioelectronic interface that directly links wireless-powered electrical stimulation of human cells to either synthetic promoter-driven transgene expression or rapid secretion of constitutively expressed protein therapeutics from vesicular stores. Electrogenetic control was achieved by coupling ectopic expression of the L-type voltage-gated channel CaV1.2 and the inwardly rectifying potassium channel Kir2.1 to the desired output through endogenous calcium signaling. Focusing on type 1 diabetes, we engineered electrosensitive human ß cells (Electroß cells). Wireless electrical stimulation of Electroß cells inside a custom-built bioelectronic device provided real-time control of vesicular insulin release; insulin levels peaked within 10 minutes. When subcutaneously implanted, this electrotriggered vesicular release system restored normoglycemia in type 1 diabetic mice.


Assuntos
Diabetes Mellitus Experimental/terapia , Diabetes Mellitus Tipo 1/terapia , Estimulação Elétrica/instrumentação , Secreção de Insulina/genética , Células Secretoras de Insulina/metabolismo , Tecnologia sem Fio/instrumentação , Animais , Biônica , Canais de Cálcio Tipo L/genética , Sinalização do Cálcio , Engenharia Celular , Células HEK293 , Humanos , Masculino , Camundongos , Canais de Potássio Corretores do Fluxo de Internalização/genética , Próteses e Implantes , Transcrição Genética , Transgenes
13.
Nat Commun ; 11(1): 2099, 2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32350248

RESUMO

Besides pro-inflammatory roles, the ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate IL-17 signaling in neurons, and the extent it can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans neurons. We identify the paracaspase MALT-1 as a critical output of the pathway. MALT1 mediates signaling from many immune receptors in mammals, but was not previously implicated in IL-17 signaling or nervous system function. C. elegans MALT-1 forms a complex with homologs of Act1 and IRAK and appears to function both as a scaffold and a protease. MALT-1 is expressed broadly in the C. elegans nervous system, and neuronal IL-17-MALT-1 signaling regulates multiple phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural circuit function downstream of IL-17 to remodel physiology and behavior.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/fisiologia , Imunidade , Interleucina-17/metabolismo , Longevidade , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Neurônios/metabolismo , Animais , Comportamento Animal , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Fluorescência Verde/metabolismo , Imunidade/efeitos dos fármacos , Interneurônios/efeitos dos fármacos , Interneurônios/fisiologia , Longevidade/efeitos dos fármacos , Modelos Biológicos , Neurônios/efeitos dos fármacos , Oxigênio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transgenes
14.
Nat Commun ; 11(1): 2494, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427850

RESUMO

Artificially improving traits of cultivated alfalfa (Medicago sativa L.), one of the most important forage crops, is challenging due to the lack of a reference genome and an efficient genome editing protocol, which mainly result from its autotetraploidy and self-incompatibility. Here, we generate an allele-aware chromosome-level genome assembly for the cultivated alfalfa consisting of 32 allelic chromosomes by integrating high-fidelity single-molecule sequencing and Hi-C data. We further establish an efficient CRISPR/Cas9-based genome editing protocol on the basis of this genome assembly and precisely introduce tetra-allelic mutations into null mutants that display obvious phenotype changes. The mutated alleles and phenotypes of null mutants can be stably inherited in generations in a transgene-free manner by cross pollination, which may help in bypassing the debate about transgenic plants. The presented genome and CRISPR/Cas9-based transgene-free genome editing protocol provide key foundations for accelerating research and molecular breeding of this important forage crop.


Assuntos
Cromossomos de Plantas/genética , Edição de Genes/métodos , Genoma de Planta/genética , Medicago sativa/genética , Tetraploidia , Transgenes/genética , Alelos , Sistemas CRISPR-Cas , Produtos Agrícolas/genética , Mutação , Fenótipo , Melhoramento Vegetal/métodos
15.
Nature ; 583(7818): 830-833, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32380511

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), which has become a public health emergency of international concern1. Angiotensin-converting enzyme 2 (ACE2) is the cell-entry receptor for severe acute respiratory syndrome coronavirus (SARS-CoV)2. Here we infected transgenic mice that express human ACE2 (hereafter, hACE2 mice) with SARS-CoV-2 and studied the pathogenicity of the virus. We observed weight loss as well as virus replication in the lungs of hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of considerable numbers of macrophages and lymphocytes into the alveolar interstitium, and the accumulation of macrophages in alveolar cavities. We observed viral antigens in bronchial epithelial cells, macrophages and alveolar epithelia. These phenomena were not found in wild-type mice infected with SARS-CoV-2. Notably, we have confirmed the pathogenicity of SARS-CoV-2 in hACE2 mice. This mouse model of SARS-CoV-2 infection will be valuable for evaluating antiviral therapeutic agents and vaccines, as well as understanding the pathogenesis of COVID-19.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Pulmão/patologia , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Transgenes , Animais , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Betacoronavirus/imunologia , Betacoronavirus/metabolismo , Brônquios/patologia , Brônquios/virologia , Infecções por Coronavirus/imunologia , Modelos Animais de Doenças , Células Epiteliais/patologia , Células Epiteliais/virologia , Feminino , Humanos , Imunoglobulina G/imunologia , Pulmão/imunologia , Pulmão/virologia , Linfócitos/imunologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/virologia , Masculino , Camundongos , Camundongos Transgênicos , Pandemias , Pneumonia Viral/imunologia , Receptores de Complemento 3d/genética , Receptores de Complemento 3d/metabolismo , Replicação Viral , Perda de Peso
16.
Nat Commun ; 11(1): 2214, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32371941

RESUMO

MSH1 is a plant-specific protein. RNAi suppression of MSH1 results in phenotype variability for developmental and stress response pathways. Segregation of the RNAi transgene produces non-genetic msh1 'memory' with multi-generational inheritance. First-generation memory versus non-memory comparison, and six-generation inheritance studies, identifies gene-associated, heritable methylation repatterning. Genome-wide methylome analysis integrated with RNAseq and network-based enrichment studies identifies altered circadian clock networks, and phytohormone and stress response pathways that intersect with circadian control. A total of 373 differentially methylated loci comprising these networks are sufficient to discriminate memory from nonmemory full sibs. Methylation inhibitor 5-azacytidine diminishes the differences between memory and wild type for growth, gene expression and methylation patterning. The msh1 reprogramming is dependent on functional HISTONE DEACETYLASE 6 and methyltransferase MET1, and transition to memory requires the RNA-directed DNA methylation pathway. This system of phenotypic plasticity may serve as a potent model for defining accelerated plant adaptation during environmental change.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Metilação de DNA , Proteína MutS de Ligação de DNA com Erro de Pareamento/genética , Característica Quantitativa Herdável , Interferência de RNA , Transgenes/genética , Adaptação Fisiológica/genética , DNA (Citosina-5-)-Metiltransferases/genética , Epigênese Genética , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Redes Reguladoras de Genes , Estudo de Associação Genômica Ampla/métodos , Desacetilase 6 de Histona/genética , Padrões de Herança/genética , Plantas Geneticamente Modificadas , Transdução de Sinais/genética
17.
J Neurosci ; 40(20): 3896-3914, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32300046

RESUMO

Optic neuropathies are a group of optic nerve (ON) diseases caused by various insults including glaucoma, inflammation, ischemia, trauma, and genetic deficits, which are characterized by retinal ganglion cell (RGC) death and ON degeneration. An increasing number of genes involved in RGC intrinsic signaling have been found to be promising neural repair targets that can potentially be modulated directly by gene therapy, if we can achieve RGC specific gene targeting. To address this challenge, we first used adeno-associated virus (AAV)-mediated gene transfer to perform a low-throughput in vivo screening in both male and female mouse eyes and identified the mouse γ-synuclein (mSncg) promoter, which specifically and potently sustained transgene expression in mouse RGCs and also works in human RGCs. We further demonstrated that gene therapy that combines AAV-mSncg promoter with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing can knock down pro-degenerative genes in RGCs and provide effective neuroprotection in optic neuropathies.SIGNIFICANCE STATEMENT Here, we present an RGC-specific promoter, mouse γ-synuclein (mSncg) promoter, and perform extensive characterization and proof-of-concept studies of mSncg promoter-mediated gene expression and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing in RGCs in vivo To our knowledge, this is the first report demonstrating in vivo neuroprotection of injured RGCs and optic nerve (ON) by AAV-mediated CRISPR/Cas9 inhibition of genes that are critical for neurodegeneration. It represents a powerful tool to achieve RGC-specific gene modulation, and also opens up a promising gene therapy strategy for optic neuropathies, the most common form of eye diseases that cause irreversible blindness.


Assuntos
Regulação da Expressão Gênica/genética , Edição de RNA/genética , Células Ganglionares da Retina/metabolismo , gama-Sinucleína/genética , Animais , Sistemas CRISPR-Cas , Dependovirus/genética , Feminino , Deleção de Genes , Terapia Genética , Humanos , Células-Tronco Pluripotentes Induzidas , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nervo Óptico/patologia , Doenças do Nervo Óptico/genética , Doenças do Nervo Óptico/terapia , Células Ganglionares da Retina/patologia , Transgenes/genética
18.
PLoS One ; 15(4): e0232045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330156

RESUMO

The functional efficiency of the expression cassettes integrated into a plasmid and a PCR- amplified fragment was comparatively analyzed after transient transfection in vitro or introduction into the developing embryo of Danio rerio. The cassettes contained the reporter genes, luciferase of Photinus pyralis (luc) or enhanced green fluorescent protein, under the control of the promoter of human cytomegalovirus immediate-early genes. In the in vitro system, the efficiency of the circular plasmid was 2.5 times higher than that of the PCR- amplified fragment. The effect of mutations in the expression cassette on the efficiency of the transgene expression in the PCR- amplified fragment was quantitatively evaluated. The mutations generated after 25 amplification cycles with Taq DNA polymerase decreased luciferase activity in transfected cells by 65-85%. Thus, mutations are the key factor of decreased functional efficiency of the PCR- amplified fragment relative to the circular plasmid in this experimental model, while other factors apparently have a lesser impact. At the organism level, no significant difference in the expression efficiency of the plasmid and PCR- amplified fragment has been revealed. Comparison of the vector efficiencies in in vivo and in vitro systems demonstrates that the level of luciferase in the D. rerio cell lysate, normalized to the molar concentration of the vector, is by three orders of magnitude higher than that after the cell transfection in vitro, which indicates that the quantitative data obtained for in vitro systems should not be directly extrapolated to the organism level.


Assuntos
Genes Reporter/genética , Vetores Genéticos/genética , Reação em Cadeia da Polimerase/métodos , Animais , Linhagem Celular Tumoral , Eficiência/fisiologia , Vaga-Lumes/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Luciferases/metabolismo , Plasmídeos/genética , Regiões Promotoras Genéticas/genética , Transfecção/métodos , Transgenes/genética , Peixe-Zebra/metabolismo
19.
Mol Biotechnol ; 62(4): 260-272, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32144553

RESUMO

Pre-existing immune response against adenovirus could diminish transgene expression efficiency when Ad is employed in humans as gene therapy vector. We previously used Ad-hΔuPA (Recombinant adenovirus expressing human urokinase-type plasminogen activator) as antifibrotic gene therapy in cirrhosis models and demonstrated its effectiveness. As a further clinical approach, transient Cyclosporine A (CsA) immunosuppression was induced in cirrhotic animals to determine whether Ad-hΔuPA administration retained efficacy. Adenovirus sensitization was achieved by systemic administration of non-therapeutic Ad-ßGal (Recombinant adenovirus expressing beta-galactosidase) after 4 weeks of intraperitoneal carbon tetrachloride (CCl4) regimen. Cirrhosis induction continued up to 8 weeks. At the end of CCl4 intoxication, immunosuppression was achieved with three CsA doses (40 mg/kg) as follows: 24 h before administration of Ad-hΔuPA, at the moment of Ad-hΔuPA injection and finally, 24 h after Ad-hΔuPA inoculation. At 2 and 72 h after Ad-hΔuPA injection, animals were sacrificed. Liver, spleen, lung, kidney, heart, brain, and testis were analyzed for Ad-biodistribution and transgene expression. In naïve animals, Ad-hΔuPA genomes prevailed in liver and spleen, while Ad-sensitized rats showed Ad genomes also in their kidney and heart. Cirrhosis and Ad preimmunization status notably diminished transgene liver expression compared to healthy livers. CsA immunosuppression in cirrhotic animals has no effect on Ad-hΔuPA biodistribution, but increments survival.


Assuntos
Adenoviridae/genética , Adenoviridae/metabolismo , Cirrose Hepática/terapia , Ativador de Plasminogênio Tipo Uroquinase/genética , Animais , Tetracloreto de Carbono/administração & dosagem , Ciclosporina/uso terapêutico , Terapia Genética , Imunização , Imunossupressores/uso terapêutico , Cirrose Hepática/enzimologia , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Ratos , Distribuição Tecidual , Transgenes , Ativador de Plasminogênio Tipo Uroquinase/farmacocinética
20.
Mol Biotechnol ; 62(4): 252-259, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32146690

RESUMO

Classic toxicology studies often utilize in vivo animal models. Newer approaches employing in vitro organ-specific cellular models have been developed in recent years to help accelerate the speed and reduce the cost of traditional toxicology testing. Toward the goal of supporting in vitro cellular model research with a regulatory application in mind, we have developed a 'designer' human kidney cell line called HK2-Vi that can fluorescently measure the cytotoxicity of potential toxins on proximal tubule cell viability in a direct exposure in vitro model. HK2-Vi was designed to be a reagent-less kinetic assay that can yield data on short- or long-term cell viability after toxin exposure. To generate HK2-Vi, we used monocistronic lentiviral transduction methods to genetically engineer a human kidney cell line called HK-2 to stably co-express two transgenes. The first is Perceval HR, which encodes a fluorescent biosensor of both cytosolic ATP and ADP and the second is pHRed, which encodes a biosensor of cytosolic pH. Relative levels of cellular ATP and ADP effectively serve as a reliable and robust indicator of cell viability. Because the fluorescence Perceval HR is pH-dependent, we co-expressed the pHRed genetic biosensor to correct for variations in pH if necessary. Heterogenous populations of transduced renal cells were enriched by flow cytometry before monoclonal cellular populations were isolated by cell culture methods. A single clonal population of co-transduced cells expressing both Perceval HR and pHRed was selected to be HK2-Vi. This established cell line can now serve as a tool for in vitro toxicology testing and the methods described herein serve as a model for developing designer cell lines derived from other organs.


Assuntos
Linhagem Celular , Túbulos Renais Proximais/efeitos dos fármacos , Testes de Toxicidade , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Técnicas Biossensoriais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fluorescência , Engenharia Genética , Humanos , Concentração de Íons de Hidrogênio , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/metabolismo , Transgenes
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