Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20.859
Filtrar
2.
Yi Chuan ; 41(8): 686-702, 2019 Aug 20.
Artigo em Chinês | MEDLINE | ID: mdl-31447420

RESUMO

Spermatogonial stem cells (SSCs) are male germline stem cells that reside in the basement membrane of the seminiferous tubule in the testis. SSCs are characterized by their capability of self-renewal to maintain the stem cell pool throughout the lifespan and commitments to germ line after puberty, thus transmitting the genetic information from parents to the SSC-derived progenies. SSCs can be isolated from testis, propagated in vitro, and induced to differentiate into varied germ cells. Although significant progress has been made in the field of rodent SSCs, the SSCs of large animals have advanced slowly. Studies on SSCs of large animal models can offer insights into the physiological and pathological mechanism of human reproduction. Moreover, SSCs of agricultural large animals can be used as an essential tool for multiplication of elite animal individuals, and generation of genetically modified livestock with valuable economic traits. In this review, we summarize the recent progress on SSCs of large animal models for agricultural and medical purposes, and discuss the present problems and future prospects. This review can give an overall view of large animal SSCs as respect to their applications in novel alternative reproductive technologies, generation of transgenic animals, treatment of male infertility and regenerative medicine.


Assuntos
Espermatogônias/citologia , Células-Tronco/citologia , Animais , Animais Geneticamente Modificados , Humanos , Infertilidade Masculina , Masculino , Modelos Animais , Testículo/citologia
3.
Ecotoxicol Environ Saf ; 182: 109449, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398778

RESUMO

The flame retardant, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), is one of the most developmentally toxic organophosphate flame retardants (OPFRs). However, few mechanistic studies on phenotypic malformation caused by TDCIPP have been conducted. This study investigates the molecular mechanism underlying abnormal tail fin development consistently observed in zebrafish embryos exposed to TDCIPP. The results show that the defects in the tail fin (e.g., bent spine, defective caudal fin, and damaged tip) were associated with altered expression of transcription factors. The significant up-regulation of mmp9 and, among insulin-growth factor (IGF) families, igfbp-1a and igfbp1b was observed, whereas alterations in the expression of cdx4, igf1a, ifg1b, igf2b, and vegaa regulating tail development were dependent on time points. In accordance with changes in mRNA gene expression, TDCIPP impaired vessel formation and disorganized muscle in transgenic Tg(fli-GFP) zebrafish larvae. Furthermore, we found that the overexpression of mmp9 caused by TDCIPP was not linked to igfbp-1. Overall, these findings demonstrate that TDCIPP disrupts the progression of tail fin development, accompanied by defects in vessel and muscle formation in developing zebrafish embryos.


Assuntos
Desenvolvimento Embrionário/efeitos dos fármacos , Retardadores de Chama/toxicidade , Compostos Organofosforados/toxicidade , Animais , Animais Geneticamente Modificados , Retardadores de Chama/metabolismo , Larva , Organofosfatos/metabolismo , Fosfatos/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
4.
Chem Commun (Camb) ; 55(68): 10142-10145, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389424

RESUMO

Hydrogen sulfide, an endogenous signalling molecule, is central to several pathophysiological processes in mammalian systems. It scavenges reactive oxygen species and is known to ameliorate dopaminergic neuronal degeneration in neurotoxin-induced Parkinson's disease models. The rapid volatilization of H2S from spontaneously releasing sulfide salts being a challenge, we describe peptide conjugates which exhibit tris(2-carboxyethyl)phosphine mediated "slow and sustained" H2S release. These conjugates reduced hydrogen peroxide-induced oxidative stress and significantly increased dopamine levels in transgenic C. elegans.


Assuntos
Dopamina/metabolismo , Sulfeto de Hidrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peptídeos/farmacologia , Tionas/farmacologia , Tiofenos/farmacologia , Animais , Animais Geneticamente Modificados , Anti-Inflamatórios/metabolismo , Antioxidantes/metabolismo , Caenorhabditis elegans/genética , Liberação Controlada de Fármacos , Oxirredução , Peptídeos/síntese química , Peptídeos/química , Fosfinas/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Tionas/síntese química , Tionas/química , Tiofenos/síntese química , Tiofenos/química , alfa-Sinucleína/genética
5.
Dokl Biochem Biophys ; 486(1): 187-191, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31367818

RESUMO

Using transgenic Drosophila model systems, we showed that four binding sites for the architectural protein dCTCF per se cannot form an effective insulator that blocks enhancers and protects against the Polycomb-dependent repression. These results suggest that, in the known Drosophila insulators, the dCTCF protein functions in cooperation with other architectural proteins.


Assuntos
Fator de Ligação a CCCTC/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Animais , Animais Geneticamente Modificados
6.
Nat Commun ; 10(1): 3054, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296860

RESUMO

Two waves of DNA methylation reprogramming occur during mammalian embryogenesis; during preimplantation development and during primordial germ cell (PGC) formation. However, it is currently unclear how evolutionarily conserved these processes are. Here we characterise the DNA methylomes of zebrafish PGCs at four developmental stages and identify retention of paternal epigenetic memory, in stark contrast to the findings in mammals. Gene expression profiling of zebrafish PGCs at the same developmental stages revealed that the embryonic germline is defined by a small number of markers that display strong developmental stage-specificity and that are independent of DNA methylation-mediated regulation. We identified promoters that are specifically targeted by DNA methylation in somatic and germline tissues during vertebrate embryogenesis and that are frequently misregulated in human cancers. Together, these detailed methylome and transcriptome maps of the zebrafish germline provide insight into vertebrate DNA methylation reprogramming and enhance our understanding of the relationships between germline fate acquisition and oncogenesis.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica no Desenvolvimento/genética , Células Germinativas/crescimento & desenvolvimento , Herança Paterna , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Embrião não Mamífero , Desenvolvimento Embrionário/genética , Epigênese Genética/fisiologia , Perfilação da Expressão Gênica , Regiões Promotoras Genéticas/genética , Sequenciamento Completo do Genoma
7.
Nat Commun ; 10(1): 3049, 2019 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296872

RESUMO

The transcription factor p63 is a master regulator of ectoderm development. Although previous studies show that p63 triggers epidermal differentiation in vitro, the roles of p63 in developing embryos remain poorly understood. Here, we use zebrafish embryos to analyze in vivo how p63 regulates gene expression during development. We generate tp63-knock-out mutants that recapitulate human phenotypes and show down-regulated epidermal gene expression. Following p63-binding dynamics, we find two distinct functions clearly separated in space and time. During early development, p63 binds enhancers associated to neural genes, limiting Sox3 binding and reducing neural gene expression. Indeed, we show that p63 and Sox3 are co-expressed in the neural plate border. On the other hand, p63 acts as a pioneer factor by binding non-accessible chromatin at epidermal enhancers, promoting their opening and epidermal gene expression in later developmental stages. Therefore, our results suggest that p63 regulates cell fate decisions during vertebrate ectoderm specification.


Assuntos
Ectoderma/embriologia , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Placa Neural/embriologia , Fosfoproteínas/metabolismo , Transativadores/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas/genética , Diferenciação Celular/genética , Cromatina/metabolismo , Regulação para Baixo , Ectoderma/metabolismo , Embrião não Mamífero , Elementos Facilitadores Genéticos/genética , Epiderme/embriologia , Epiderme/metabolismo , Técnicas de Inativação de Genes , Modelos Animais , Placa Neural/metabolismo , Fosfoproteínas/genética , Ligação Proteica/genética , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Transativadores/genética , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/genética
8.
Cell Prolif ; 52(5): e12656, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31264309

RESUMO

OBJECTIVES: Cell migration has a key role in cancer metastasis, which contributes to drug resistance and tumour recurrence. Better understanding of the mechanisms involved in this process will potentially reveal new drug targets for cancer therapy. Fer is a non-receptor protein tyrosine kinase aberrantly expressed in various human cancers, whereas its role in tumour progression remains elusive. MATERIALS AND METHODS: Transgenic flies and epigenetic analysis were employed to investigate the role of Drosophila Fer (FER) in cell migration and underlying mechanisms. Co-immunoprecipitation assay was used to monitor the interaction between FER and Drosophila JNK (Bsk). The conservation of Fer in regulating JNK signalling was explored in mammalian cancer and non-cancer cells. RESULTS: Overexpression of FER triggered cell migration and activated JNK signalling in the Drosophila wing disc. Upregulation and downregulation in the basal activity of Bsk exacerbated and eliminated FER-mediated migration, respectively. In addition, loss of FER blocked signal transduction of the JNK pathway. Specifically, FER interacted with and promoted the activity of Bsk, which required both the kinase domain and the C-terminal of Bsk. Lastly, Fer regulated JNK activities in mammalian cells. CONCLUSIONS: Our study reveals FER as a positive regulator of JNK-mediated cell migration and suggests its potential role as a therapeutic target for cancer metastasis.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Tirosina Quinases/metabolismo , Animais , Animais Geneticamente Modificados/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proteínas de Drosophila/química , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/química , Metaloproteinase 1 da Matriz/metabolismo , Domínios Proteicos , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/genética , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais , Asas de Animais/metabolismo
9.
Nat Methods ; 16(8): 763-770, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31308547

RESUMO

Current techniques for monitoring GABA (γ-aminobutyric acid), the primary inhibitory neurotransmitter in vertebrates, cannot follow transients in intact neural circuits. To develop a GABA sensor, we applied the design principles used to create the fluorescent glutamate receptor iGluSnFR. We used a protein derived from a previously unsequenced Pseudomonas fluorescens strain and performed structure-guided mutagenesis and library screening to obtain intensity-based GABA sensing fluorescence reporter (iGABASnFR) variants. iGABASnFR is genetically encoded, detects GABA release evoked by electric stimulation of afferent fibers in acute brain slices and produces readily detectable fluorescence increases in vivo in mice and zebrafish. We applied iGABASnFR to track mitochondrial GABA content and its modulation by an anticonvulsant, swimming-evoked, GABA-mediated transmission in zebrafish cerebellum, GABA release events during interictal spikes and seizures in awake mice, and found that GABA-mediated tone decreases during isoflurane anesthesia.


Assuntos
Técnicas Biossensoriais/métodos , Encéfalo/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Hipocampo/metabolismo , Imagem Molecular/métodos , Neurônios/metabolismo , Ácido gama-Aminobutírico/metabolismo , Anestesia , Animais , Animais Geneticamente Modificados , Feminino , Proteínas de Fluorescência Verde/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Convulsões/metabolismo , Convulsões/patologia , Peixe-Zebra
10.
Cell Mol Biol Lett ; 24: 44, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31285745

RESUMO

Background: Deer antler is the only mammalian organ that can be completely regenerated every year. Its periodic regeneration is regulated by multiple factors, including transforming growth factor ß (TGF-ß). This widely distributed multi-functional growth factor can control the proliferation and differentiation of many types of cell, and it may play a crucial regulatory role in antler regeneration. This study explored the role of TGF-ß1 during the rapid growth of sika deer antler. Methods: Three CRISPR-Cas9 knockout vectors targeting the TGF-ß1 gene of sika deer were constructed and packaged with a lentiviral system. The expression level of TGF-ß1 protein in the knockout cell line was determined using western blot, the proliferation and migration of cartilage cells in vitro were respectively determined using EdU and the cell scratch test, and the expression levels of TGF-ß pathway-related genes were determined using a PCR array. Results: Of the three gRNAs designed, pBOBI-gRNA2 had the best knockout effect. Knockout of TGF-ß1 gene inhibits the proliferation of cartilage cells and enhances their migration in vitro. TGF-ß signaling pathway-related genes undergo significant changes, so we speculate that when the TGF-ß pathway is blocked, the BMP signaling pathway mediated by BMP4 may play a key role. Conclusions: TGF-ß1 is a newly identified regulatory factor of rapid growth in sika deer antler.


Assuntos
Cartilagem/metabolismo , Proliferação de Células , Cervos/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta1/metabolismo , Animais , Animais Geneticamente Modificados , Chifres de Veado , Sistemas CRISPR-Cas , Cartilagem/fisiologia , Linhagem Celular , Cervos/genética , Cervos/fisiologia , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Masculino , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/fisiologia
11.
Parasit Vectors ; 12(1): 357, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31324262

RESUMO

BACKGROUND: Evaluating and improving mating success and competitive ability of laboratory-reared transgenic mosquito strains will enhance the effectiveness of proposed disease-control strategies that involve deployment of transgenic strains. Two components of the mosquito rearing process, larval diet quantity and aquatic environment - which are linked to physiological and behavioural differences in adults - are both relatively easy to manipulate. In mosquitoes, as for many other arthropod species, the quality of the juvenile habitat is strongly associated with adult fitness characteristics, such as longevity and fecundity. However, the influence of larval conditioning on mating performance is poorly understood. Here, we investigated the combined effects of larval diet amount and environmental water source on adult male mating success in a genetically modified strain of Aedes aegypti mosquitoes in competition with wild-type conspecifics. Importantly, this research was conducted in a field setting using low generation laboratory and wild-type lines. RESULTS: By controlling larval diet (high and low) and rearing water source (field-collected and laboratory water), we generated four treatment lines of a genetically modified strain of Ae. aegypti tagged with fluorescent sperm. Laboratory reared mosquitoes were then competed against a low generation wild-type colony in a series of laboratory and semi-field mating experiments. While neither food quantity nor larval aquatic environment were found to affect male mating fitness, the transgenic lines consistently outperformed wild-types in laboratory competition assays, an advantage that was not conferred to semi-field tests. CONCLUSIONS: Using a model transgenic system, our results indicate that differences in the experimental conditions of laboratory- and field-based measures of mating success can lead to variation in the perceived performance ability of modified strains if they are only tested in certain environments. While there are many potential sources of variation between laboratory and field lines, laboratory adaptation - which may occur over relatively few generations in this species - may directly impact mating ability depending on the context in which it is measured. We suggest that colony-hybridization with field material can potentially be used to mitigate these effects in a field setting. Release programs utilising mass-produced modified laboratory strains should incorporate comparative assessments of quality in candidate lines.


Assuntos
Aedes/fisiologia , Animais Geneticamente Modificados , Comportamento Sexual Animal , Aedes/genética , Animais , Feminino , Larva/fisiologia , Longevidade , Masculino , Reprodução , Espermatozoides/fisiologia
12.
Toxicol Lett ; 314: 43-52, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31310794

RESUMO

Thioredoxin is an evolutionarily conserved antioxidant protein that plays a crucial role for fundamental cellular processes and embryonic development. Growing evidence support that Thioredoxin influences cellular response to chemicals insults, particularly those accompanying oxidative stress. The mechanisms underlying the functions of Thioredoxin1 in the embryonic development under the environmental toxicant exposure remain, however, largely unexplored. We report here that thioredoxin1 becomes differentially expressed in zebrafish embryos after exposure to 9 out of 11 environmental chemicals. In situ gene expression analysis show that thioredoxin1 is expressed in neurons, olfactory epithelia, liver and swim bladder under normal conditions. After MeHg exposure, however, thioredoxin1 is ectopically induced in the hair cells of the lateral line and in epithelia cells of the pharynx. Knockdown of Thioredoxin1 induces hydrocephalus and increases cell apoptosis in the brain ventricular epithelia cells. In comparison with 5% malformation in embryos injected with control morpholino, MeHg induces more than 77% defects in Thioredoxin1 knockdown embryos. Our data suggest that there is an association between hydrocephalus and Thioredoxin1 malfunction in embryonic development, and provide valuable information to elucidate the protective role of Thioredoxin1 against chemicals disruption.


Assuntos
Encéfalo/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Hidrocefalia/induzido quimicamente , Tiorredoxinas/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/metabolismo , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Embrião não Mamífero/patologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica no Desenvolvimento , Hidrocefalia/embriologia , Hidrocefalia/genética , Hidrocefalia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Tiorredoxinas/genética , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
13.
PLoS Genet ; 15(6): e1008221, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31242186

RESUMO

Wolbachia are maternally inherited bacteria that infect arthropod species worldwide and are deployed in vector control to curb arboviral spread using cytoplasmic incompatibility (CI). CI kills embryos when an infected male mates with an uninfected female, but the lethality is rescued if the female and her embryos are likewise infected. Two phage WO genes, cifAwMel and cifBwMel from the wMel Wolbachia deployed in vector control, transgenically recapitulate variably penetrant CI, and one of the same genes, cifAwMel, rescues wild type CI. The proposed Two-by-One genetic model predicts that CI and rescue can be recapitulated by transgenic expression alone and that dual cifAwMel and cifBwMel expression can recapitulate strong CI. Here, we use hatch rate and gene expression analyses in transgenic Drosophila melanogaster to demonstrate that CI and rescue can be synthetically recapitulated in full, and strong, transgenic CI comparable to wild type CI is achievable. These data explicitly validate the Two-by-One model in wMel-infected D. melanogaster, establish a robust system for transgenic studies of CI in a model system, and represent the first case of completely engineering male and female animal reproduction to depend upon bacteriophage gene products.


Assuntos
Bacteriófagos/genética , Drosophila melanogaster/genética , Proteínas Virais/genética , Wolbachia/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/crescimento & desenvolvimento , Citoplasma/genética , Citoplasma/metabolismo , Citoplasma/microbiologia , Vetores de Doenças , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/microbiologia , Feminino , Regulação da Expressão Gênica/genética , Masculino , Herança Materna/genética , Reprodução/genética , Wolbachia/patogenicidade , Wolbachia/virologia
14.
PLoS Genet ; 15(6): e1008158, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31194738

RESUMO

With the approach of winter, many insects switch to an alternative protective developmental program called diapause. Drosophila melanogaster females overwinter as adults by inducing a reproductive arrest that is characterized by inhibition of ovarian development at previtellogenic stages. The insulin producing cells (IPCs) are key regulators of this process, since they produce and release insulin-like peptides that act as diapause-antagonizing hormones. Here we show that in D. melanogaster two neuropeptides, Pigment Dispersing Factor (PDF) and short Neuropeptide F (sNPF) inhibit reproductive arrest, likely through modulation of the IPCs. In particular, genetic manipulations of the PDF-expressing neurons, which include the sNPF-producing small ventral Lateral Neurons (s-LNvs), modulated the levels of reproductive dormancy, suggesting the involvement of both neuropeptides. We expressed a genetically encoded cAMP sensor in the IPCs and challenged brain explants with synthetic PDF and sNPF. Bath applications of both neuropeptides increased cAMP levels in the IPCs, even more so when they were applied together, suggesting a synergistic effect. Bath application of sNPF additionally increased Ca2+ levels in the IPCs. Our results indicate that PDF and sNPF inhibit reproductive dormancy by maintaining the IPCs in an active state.


Assuntos
Proteínas CLOCK/genética , Proteínas de Drosophila/genética , Neuropeptídeos/genética , Reprodução/genética , Animais , Animais Geneticamente Modificados/genética , Encéfalo/metabolismo , Ritmo Circadiano/genética , Diapausa/genética , Diapausa/fisiologia , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Regulação da Expressão Gênica/genética , Insulina/genética , Neurônios/metabolismo , Transdução de Sinais/genética
15.
Nat Commun ; 10(1): 2679, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31213603

RESUMO

The islet in type 2 diabetes (T2D) is characterized by amyloid deposits derived from islet amyloid polypeptide (IAPP), a protein co-expressed with insulin by ß-cells. In common with amyloidogenic proteins implicated in neurodegeneration, human IAPP (hIAPP) forms membrane permeant toxic oligomers implicated in misfolded protein stress. Here, we establish that hIAPP misfolded protein stress activates HIF1α/PFKFB3 signaling, this increases glycolysis disengaged from oxidative phosphorylation with mitochondrial fragmentation and perinuclear clustering, considered a protective posture against increased cytosolic Ca2+ characteristic of toxic oligomer stress. In contrast to tissues with the capacity to regenerate, ß-cells in adult humans are minimally replicative, and therefore fail to execute the second pro-regenerative phase of the HIF1α/PFKFB3 injury pathway. Instead, ß-cells in T2D remain trapped in the pro-survival first phase of the HIF1α injury repair response with metabolism and the mitochondrial network adapted to slow the rate of cell attrition at the expense of ß-cell function.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Estresse do Retículo Endoplasmático/fisiologia , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Adulto , Animais , Animais Geneticamente Modificados , Apoptose , Linhagem Celular Tumoral , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Glicólise/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Masculino , Pessoa de Meia-Idade , Degradação Mitocondrial/fisiologia , Fosforilação Oxidativa , Fosfofrutoquinase-2/metabolismo , Agregados Proteicos/fisiologia , Ratos
16.
Nat Commun ; 10(1): 2891, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31253791

RESUMO

Our ability to manage acute myeloid leukemia (AML) is limited by our incomplete understanding of the epigenetic disruption central to leukemogenesis, including improper histone methylation. Here we examine 16 histone H3 genes in 434 primary AML samples and identify Q69H, A26P, R2Q, R8H and K27M/I mutations (1.6%), with higher incidence in secondary AML (9%). These mutations occur in pre-leukemic hematopoietic stem cells (HSCs) and exist in the major leukemic clones in patients. They increase the frequency of functional HSCs, alter differentiation, and amplify leukemic aggressiveness. These effects are dependent on the specific mutation. H3K27 mutation increases the expression of genes involved in erythrocyte and myeloid differentiation with altered H3K27 tri-methylation and K27 acetylation. The functional impact of histone mutations is independent of RUNX1 mutation, although they at times co-occur. This study establishes that H3 mutations are drivers of human pre-cancerous stem cell expansion and important early events in leukemogenesis.


Assuntos
Epigenômica , Regulação Leucêmica da Expressão Gênica/fisiologia , Histonas/metabolismo , Leucemia Mieloide Aguda/metabolismo , Animais , Animais Geneticamente Modificados , Antineoplásicos/farmacologia , Sequência de Bases , Células da Medula Óssea , Diferenciação Celular , Transformação Celular Neoplásica , DNA/genética , Drosophila melanogaster/genética , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Camundongos , Mutação , Neoplasias Experimentais
17.
Sheng Wu Gong Cheng Xue Bao ; 35(6): 1071-1078, 2019 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-31232003

RESUMO

The aim of this study is to investigate the effect of the chimeric intron in different directions on the expression of the nerve growth factor (NGF) in recombinant Chinese hamster ovary (CHO) cells. The chimeric intron that contained the splice sequence of the first intron of the human ß-globin and the human immunoglobulin heavy chain variable region intron was used. NGF gene was cloned into the expression vectors containing the chimeric intron in the forward or reverse direction, followed by transfecting into CHO cells, and screened under G418 to produce the stable transfected CHO cells. Fluorescence quantitative PCR, ELISA, and Western blotting were performed to detect the recombinant NGF gene expression in CHO cells. The results showed that the chimeric introns could significantly enhance the expression of NGF in recombinant CHO cells. Moreover, the enhancing effect on NGF expression level by the intron in the forward direction showed stronger than that of the reverse direction both at mRNA and protein level. In conclusion, the chimeric intron could increase NGF expression in stably transfected CHO cells and the effect is associated with the direction of the intron insertion.


Assuntos
Íntrons , Animais , Animais Geneticamente Modificados , Células CHO , Cricetinae , Cricetulus , Expressão Gênica , Humanos , Transfecção
18.
Nat Commun ; 10(1): 2602, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197136

RESUMO

Temperature is a key factor for determining the lifespan of both poikilotherms and homeotherms. It is believed that animals live longer at lower body temperatures. However, the precise mechanism remains largely unknown. Here, we report that autophagy serves as a boost mechanism for longevity at low temperature in the nematode Caenorhabditis elegans. The adiponectin receptor AdipoR2 homolog PAQR-2 signaling detects temperature drop and augments the biosynthesis of two ω-6 polyunsaturated fatty acids, γ-linolenic acid and arachidonic acid. These two polyunsaturated fatty acids in turn initiate autophagy in the epidermis, delaying an age-dependent decline in collagen contents, and extending the lifespan. Our findings reveal that the adiponectin receptor PAQR-2 signaling acts as a regulator linking low temperature with autophagy to extend lifespan, and suggest that such a mechanism may be evolutionally conserved among diverse organisms.


Assuntos
Autofagia/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/fisiologia , Longevidade/fisiologia , Proteínas de Membrana/fisiologia , Animais , Animais Geneticamente Modificados , Ácido Araquidônico/biossíntese , Temperatura Baixa , Colágeno/metabolismo , Epiderme/metabolismo , Ácidos Graxos Ômega-6/biossíntese , Interferência de RNA , Transdução de Sinais/fisiologia
19.
Nat Commun ; 10(1): 2593, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197139

RESUMO

Prion-like domains (PLDs), defined by their low sequence complexity and intrinsic disorder, are present in hundreds of human proteins. Although gain-of-function mutations in the PLDs of neuronal RNA-binding proteins have been linked to neurodegenerative disease progression, the physiological role of PLDs and their range of molecular functions are still largely unknown. Here, we show that the PLD of Drosophila Imp, a conserved component of neuronal ribonucleoprotein (RNP) granules, is essential for the developmentally-controlled localization of Imp RNP granules to axons and regulates in vivo axonal remodeling. Furthermore, we demonstrate that Imp PLD restricts, rather than promotes, granule assembly, revealing a novel modulatory function for PLDs in RNP granule homeostasis. Swapping the position of Imp PLD compromises RNP granule dynamic assembly but not transport, suggesting that these two functions are uncoupled. Together, our study uncovers a physiological function for PLDs in the spatio-temporal control of neuronal RNP assemblies.


Assuntos
Transporte Axonal/fisiologia , Grânulos Citoplasmáticos/metabolismo , Proteínas de Drosophila/metabolismo , Domínios Proteicos/fisiologia , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Animais Geneticamente Modificados , Axônios/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Linhagem Celular , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Microscopia de Fluorescência , Modelos Animais , Príons/química , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética
20.
Nat Commun ; 10(1): 2620, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197165

RESUMO

Conventional drug screens and treatments often ignore the underlying complexity of brain network dysfunctions, resulting in suboptimal outcomes. Here we ask whether we can correct abnormal functional connectivity of the entire brain by identifying and combining multiple neuromodulators that perturb connectivity in complementary ways. Our approach avoids the combinatorial complexity of screening all drug combinations. We develop a high-speed platform capable of imaging more than 15000 neurons in 50ms to map the entire brain functional connectivity in large numbers of vertebrates under many conditions. Screening a panel of drugs in a zebrafish model of human Dravet syndrome, we show that even drugs with related mechanisms of action can modulate functional connectivity in significantly different ways. By clustering connectivity fingerprints, we algorithmically select small subsets of complementary drugs and rapidly identify combinations that are significantly more effective at correcting abnormal networks and reducing spontaneous seizures than monotherapies, while minimizing behavioral side effects. Even at low concentrations, our polytherapy performs superior to individual drugs even at highest tolerated concentrations.


Assuntos
Epilepsias Mioclônicas/tratamento farmacológico , Modelos Biológicos , Rede Nervosa/efeitos dos fármacos , Fenômenos Fisiológicos do Sistema Nervoso/efeitos dos fármacos , Neurotransmissores/farmacologia , Algoritmos , Animais , Animais Geneticamente Modificados , Comportamento Animal/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Sinergismo Farmacológico , Quimioterapia Combinada/métodos , Epilepsias Mioclônicas/genética , Epilepsias Mioclônicas/patologia , Ensaios de Triagem em Larga Escala/métodos , Humanos , Microscopia Confocal/métodos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Neurotransmissores/uso terapêutico , Peixe-Zebra
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA