Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Proc Natl Acad Sci U S A ; 113(6): 1612-7, 2016 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-26802121

RESUMO

Receptor-induced NF-κB activation is controlled by NEMO, the NF-κB essential modulator. Hypomorphic NEMO mutations result in X-linked ectodermal dysplasia with anhidrosis and immunodeficiency, also referred to as NEMO syndrome. Here we describe a distinct group of patients with NEMO C-terminal deletion (ΔCT-NEMO) mutations. Individuals harboring these mutations develop inflammatory skin and intestinal disease in addition to ectodermal dysplasia with anhidrosis and immunodeficiency. Both primary cells from these patients, as well as reconstituted cell lines with this deletion, exhibited increased IκB kinase (IKK) activity and production of proinflammatory cytokines. Unlike previously described loss-of-function mutations, ΔCT-NEMO mutants promoted increased NF-κB activation in response to TNF and Toll-like receptor stimulation. Investigation of the underlying mechanisms revealed impaired interactions with A20, a negative regulator of NF-κB activation, leading to prolonged accumulation of K63-ubiquitinated RIP within the TNFR1 signaling complex. Recruitment of A20 to the C-terminal domain of NEMO represents a novel mechanism limiting NF-κB activation by NEMO, and its absence results in autoinflammatory disease.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Quinase I-kappa B/química , Quinase I-kappa B/metabolismo , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Estudos de Casos e Controles , Linhagem Celular , Núcleo Celular/metabolismo , Citocinas/biossíntese , Enzima Desubiquitinante CYLD , Feminino , Regulação da Expressão Gênica , Humanos , Quinase I-kappa B/genética , Imunidade Inata , Inflamação/imunologia , Inflamação/patologia , Masculino , Monócitos/metabolismo , Proteínas Mutantes/metabolismo , Mutação/genética , Linhagem , Fenótipo , Poliubiquitina/metabolismo , Estrutura Terciária de Proteína , Transporte Proteico , Receptores do Fator de Necrose Tumoral/metabolismo , Linfócitos T/metabolismo , Receptores Toll-Like/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Proteínas Supressoras de Tumor/metabolismo , Ubiquitinação
2.
Appl Opt ; 57(12): 3159-3165, 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29714350

RESUMO

Higher spatial resolution indicates sharper recognition ability in applications. To improve the spatial resolution of volume Bragg grating spectral imagers, quantitative wave vector theory is used to elucidate the formation mechanism of diffraction blur, and the corresponding optimal design approaches are put forward. The simulation results show that the main factors for the spectral image blur are the chromatic blur and diffraction aberration, while the central wavelength deviation further deteriorates these. To deal with these factors, one must optimize the grating period, thickness, slant angle, and refractive index, as well as compress the divergence angle of the incident beam. After optimization under the guidance of the newly defined integrated merit functions, the experimental results show that the optimized smeared point-spread function is reduced by about an order of magnitude. The horizontal spatial resolution of the recorded two-dimensional monochromatic images is improved to 14.3 lines/mm under diffuse reflection illumination.

3.
Proc Natl Acad Sci U S A ; 109(12): 4443-8, 2012 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-22403062

RESUMO

Wild-type, full-length (40- and 42-residue) amyloid ß-peptide (Aß) fibrils have been shown by a variety of magnetic resonance techniques to contain cross-ß structures in which the ß-sheets have an in-register parallel supramolecular organization. In contrast, recent studies of fibrils formed in vitro by the Asp23-to-Asn mutant of 40-residue Aß (D23N-Aß(1-40)), which is associated with early onset neurodegeneration, indicate that D23N-Aß(1-40) fibrils can contain either parallel or antiparallel ß-sheets. We report a protocol for producing structurally pure antiparallel D23N-Aß(1-40) fibril samples and a series of solid state nuclear magnetic resonance and electron microscopy measurements that lead to a specific model for the antiparallel D23N-Aß(1-40) fibril structure. This model reveals how both parallel and antiparallel cross-ß structures can be constructed from similar peptide monomer conformations and stabilized by similar sets of interactions, primarily hydrophobic in nature. We find that antiparallel D23N-Aß(1-40) fibrils are thermodynamically metastable with respect to conversion to parallel structures, propagate less efficiently than parallel fibrils in seeded fibril growth, and therefore must nucleate more efficiently than parallel fibrils in order to be observable. Experiments in neuronal cell cultures indicate that both antiparallel and parallel D23N-Aß(1-40) fibrils are cytotoxic. Thus, our antiparallel D23N-Aß(1-40) fibril model represents a specific "toxic intermediate" in the aggregation process of a disease-associated Aß mutant.


Assuntos
Peptídeos beta-Amiloides/química , Amiloide/química , Fragmentos de Peptídeos/química , Doença de Alzheimer/metabolismo , Ligação Competitiva , Humanos , Espectroscopia de Ressonância Magnética/métodos , Microscopia Eletrônica/métodos , Microscopia Eletrônica de Transmissão/métodos , Modelos Biológicos , Modelos Moleculares , Conformação Molecular , Mutação , Doenças Neurodegenerativas/metabolismo , Termodinâmica
4.
Appl Opt ; 52(29): 7109-16, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-24217727

RESUMO

An experimental setup and simple method were proposed to investigate and control the actual phase profile in a high-spatial-resolution liquid-crystal optical-phased array (LCOPA). A crossed polarizer and high-resolution microscope objective were employed to transform the light distribution out of the liquid-crystal layer into a polarization-interference pattern in which the phase-profile information was wrapped. The polarization-interference pattern was then directly translated into the actual phase profile. Based on this setup, a method was developed to accurately control the actual phase profile, and the steering efficiency at the steering angle of 16 mrad was increased from 80% to 90%. The proposed method also helps in increasing the steering efficiency when disclination lines appear.

5.
Appl Opt ; 52(27): 6663-8, 2013 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-24085164

RESUMO

In this article, currently used feedback control algorithms used in the polarization controller, including a simulated annealing algorithm and a gradient algorithm, are analyzed. On this basis, a new method of polarization control feedback algorithm based on a fast locating algorithm is proposed to solve the defects of the original algorithm, such as poor convergence and an extensive time consuming search. It can reduce convergence time and improve the response speed of the polarization controllers. This new endless polarization control algorithm utilizing a four-plate polarization controller is proposed and demonstrated. The results have shown that the response time of the polarization controller is less than 1 ms. The control of polarization is achieved and the output polarization state is stable, while the light intensity fluctuated less than 2%, which can run endless resets freely.

6.
Animals (Basel) ; 13(20)2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37893991

RESUMO

In avian muscle development, embryonic muscle development determines the number of myofibers after birth. Therefore, in this study, we investigated the phenotypic differences and the molecular mechanism of pectoral muscle development of the European meat pigeon Mimas strain (later called European meat pigeon) and Shiqi pigeon on embryonic day 6 (E6), day 10 (E10), day 14 (E14) and day 1 after birth (P1). The results showed that the myofiber density of the Shiqi pigeon was significantly higher than that of the European meat pigeon on E6, and myofibers with a diameter in the range of 50~100 µm of the Shiqi pigeon on P1 were significantly higher than those of European meat pigeon. A total of 204 differential expressed genes (DEGs) were obtained from RNA-seq analysis in comparison between pigeon breeds at the same stage. DEGs related to muscle development were found to significantly enrich the cellular amino acid catabolism, carboxylic acid catabolism, extracellular matrix receptor interaction, REDOX enzyme activity, calcium signaling pathway, ECM receptor interaction, PPAR signaling pathway and other pathways. Using Cytoscape software to create mutual mapping, we identified 33 candidate genes. RT-qPCR was performed to verify the 8 DEGs selected-DES, MYOD, MYF6, PTGS1, MYF5, MYH1, MSTN and PPARG-and the results were consistent with RNA-seq. This study provides basic data for revealing the distinct embryonic development mechanism of pectoral muscle between European meat pigeons and Shiqi pigeons.

7.
Appl Opt ; 51(15): 3024-30, 2012 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-22614606

RESUMO

A configuration of hole patterned electrode liquid crystal microlens array with an ultrathin glass slab was fabricated. To reduce the fringing electric field effect and avoid the occurrence of disclination lines, an ultrathin glass slab was introduced between the patterned electrode and liquid crystal layer. The glass slab thickness played an important role in effecting the optical performance of the liquid crystal microlens array. An optimum thickness of 30 µm was selected employing numerical simulation method. Using this method, we demonstrated a microlens array that greatly improved the phase profile and focus power. The dynamic focal range of the liquid crystal microlens array may extend from <1.2 mm to >8 mm and the minimum diameter of the focus spot could be as small as 15 µm.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 268: 120656, 2022 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-34857466

RESUMO

In this work, carbon dots-doped terbium phosphonate coordination polymers (CDs-GMP/Tb) were designed and prepared as ratiometric fluorescent probes for the detection of citrate. The as-prepared CDs-GMP/Tb are prepared and have the merits of high photostability, low toxicity, and excellent biocompatibility. The as-prepared CDs-GMP/Tb as ratiometric fluorescent probes also have better anti-interference ability and stability compared with the traditional single fluorescent probe. The surface morphology, fabrication, and spectroscopy were characterized through a variety of instruments. It confirms that the probes exhibited network structure doping carbon dots. With the addition of citrate, the fluorescence of GMP/Tb at 545 nm was significantly quenched, contrasting to the enhancement of fluorescence of CDs at 454 nm. Under optimum conditions, the detection limit for citrate was 0.47 µM, with a linear range of 0-200 µM between citrate concentrations and I545/I454. It has high sensitivity, selective, and rapid detection for citrate. The as-prepared CDs-GMP/Tb as ratiometric fluorescent probes were also used for imaging citrate in living cells. These experiment results showed that CDs-GMP/Tb as ratiometric fluorescent probes could be applied to trace citrate detection in the environmental and biological fields.


Assuntos
Organofosfonatos , Pontos Quânticos , Carbono , Ácido Cítrico , Corantes Fluorescentes , Polímeros , Térbio
9.
Burns ; 48(4): 791-798, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34862090

RESUMO

BACKGROUND: Rapid diagnosis of microbes in the burn wound is a big challenge in the medical field. Traditional biochemical detection techniques take hours or days to identify the species of contaminating and drug-resistant microbes. Near-infrared spectroscopy (NIRS) is evaluated to address the need for a fast and sensitive method for the detection of bacterial contamination in liquids. METHODS: Herin, we developed a novel technique which by using NIRS together with supporting vector machine (SVM), to identify the microbial species and drug-resistant microbes in LB medium, and to diagnose the wound colonization and wound infection models of pigs. RESULTS: The device could recognize 100% of seven kinds of microbes and 99.47% of the multi-drug resistant Staphylococcus aureus (S. aureus), with a concentration of 109 cfu ml-1 in LB medium. The accuracy of the microbial identification in colonized and infected wounds in-situ was 100%. The detection limit of NIRS with SVM for the detection of S. aureus and Escherichia coli (E. coli) was 101 cfu ml-1 in LB medium. Identification time was less than 5 s. CONCLUSION: Our findings validate for the first time a novel technique aimed at the rapid, noncontacted, highly sensitive, and specific recognition of several microbial species including drug-resistant ones. This technique could represent a promising approach to identify diverse microbial species and a potential bedside device to rapidly diagnose infected wounds.


Assuntos
Queimaduras , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Infecção dos Ferimentos , Animais , Queimaduras/microbiologia , Escherichia coli , Humanos , Espectroscopia de Luz Próxima ao Infravermelho , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus , Suínos , Infecção dos Ferimentos/diagnóstico , Infecção dos Ferimentos/microbiologia
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 31(10): 2672-5, 2011 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-22250532

RESUMO

LC-based tunable filter with large aperture has been developed utilizing the effect of electric controlled birefringence. Spectral test indicated that this filter can operate in the visible band with an average 20 nm FWHM. A small scale spectral imaging system was established based on this tunable filter. Spectral imaging experiments on a certain number of samples show that this system can be tuned continuously with random-access selection of any wavelength, and has a higher level of resolving power in respect of both imaging and spectral tuning in the visible band, which has a brilliant application potentiality in biology, iatrology, environmental protection, resource detection through hyper-spectral imaging or ultra-spectral imaging.


Assuntos
Análise Espectral/métodos , Birrefringência , Cristais Líquidos , Imagem Óptica/métodos
11.
Burns Trauma ; 9: tkab014, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34258302

RESUMO

The accurate and objective evaluation of burn depth is a significant challenge in burn wound care. Herein, we used near infrared spectroscopy (NIRS) technology to measure the different depth of thermal burns in ex vivo porcine models. Based on the intensity of the spectral signals and the diffuse reflection theory, we extracted the optical parameters involved in functional (total hemoglobin and water content) and structural (tissue scattered size and scattered particles) features that reflect the changes in burn depth. Next, we applied support vector regression to construct a model including the optical property parameters and the burn depth. Finally, we histologically verified the burn depth data collected via NIRS. The results showed that our inversion model could achieve an average relative error of about 7.63%, while the NIRS technology diagnostic accuracy was in the range of 50 µm. For the first time, this novel technique provides physicians with real-time burn depth information objectively and accurately.

12.
J Neurochem ; 115(6): 1337-49, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20456019

RESUMO

Plumbagin (5-hydroxy-2-methyl-1,4 naphthoquinone) is a naturally occurring low molecular weight lipophilic phytochemical derived from roots of plants of the Plumbago genus. Plumbagin has been reported to have several clinically relevant biological activities in non-neural cells, including anti-atherosclerotic, anticoagulant, anticarcinogenic, antitumor, and bactericidal effects. In a recent screen of a panel of botanical pesticides, we identified plumbagin as having neuroprotective activity. In this study, we determined if plumbagin could modify the developmental fate of rat E14.5 embryonic neural progenitor cells (NPC). Plumbagin exhibited no cytotoxicity when applied to cultured NPC at concentrations below 1 µM. At a concentration of 0.1 µM, plumbagin significantly enhanced the proliferation of NPC as indicated by a 17% increase in the percentage of cells incorporating bromo-deoxyuridine. Plumbagin at a concentration of 0.1 pM (but not 0.1 µM), stimulated the production of astrocytes as indicated by increased GFAP expression. Plumbagin selectively induced the proliferation and differentiation of glial progenitor cells without affecting the proliferation or differentiation of neuron-restricted progenitors. Plumbagin (0.1 pM) rapidly activated the transcription factor signal transducer and activator of transcription 3 (Stat3) in NPC, and a Stat3 inhibitor peptide prevented both plumbagin-induced astrocyte formation and proliferation. These findings demonstrate the ability of a low molecular weight naturally occurring phytochemical to control the fate of glial progenitor cells by a mechanism involving the Stat3 signaling pathway.


Assuntos
Astrócitos/metabolismo , Células-Tronco Embrionárias/metabolismo , Naftoquinonas/farmacologia , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Fator de Transcrição STAT3/metabolismo , Medula Espinal/metabolismo , Células-Tronco/metabolismo , Animais , Sobrevivência Celular/fisiologia , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley , Medula Espinal/citologia
13.
ACS Appl Mater Interfaces ; 11(17): 15998-16005, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30951283

RESUMO

Lanthanide coordination polymers have been recently regarded as attractive sensing materials because of their selectivity, high sensitivity, and rapid response ability. In this research, the multiporous terbium phosphonate coordination polymer microspheres (TbP-CPs) were prepared as a novel fluorescent probe, which showed a fluorescence turn-on response capability for the detection of the trace anthrax biomarker dipicolinate acid (DPA). The morphology and chemical composition of as-prepared TbP-CPs were characterized in detail. The TbP-CPs have the vegetable-flower-like structure and microporous surface. In addition, the as-prepared TbP-CPs not only possess the merits of convenience and simple preparation with high yield but also have the excellent characters as fluorescent probes, such as high stability, good selectivity, and rapid detection ability within 30 s. This proposed sensor could detect DPA with a linear relationship in concentrations ranging from 0 to 8.0 µM and a high detection sensitivity of 5.0 nM. Furthermore, the successful applications of DPA detection in urine and bovine serum were demonstrated. As a result, the recovery ranged from 93.93-101.6%, and the relative standard deviations (RSD) were less than 5%.


Assuntos
Antraz/diagnóstico , Biomarcadores/análise , Corantes Fluorescentes/química , Microesferas , Polímeros/química , Térbio/química , Animais , Antraz/microbiologia , Bacillus anthracis/metabolismo , Biomarcadores/sangue , Biomarcadores/urina , Técnicas Biossensoriais/métodos , Humanos , Organofosfonatos/química , Ácidos Picolínicos/análise , Ácidos Picolínicos/sangue , Ácidos Picolínicos/urina , Porosidade , Espectrometria de Fluorescência
14.
Rev Sci Instrum ; 90(6): 064103, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31255006

RESUMO

The accurate and instant diagnosis of burn severity is always the key point of optimal wound management and clinical treatment. However, the accuracy of burn depth assessment is low via visual inspection and lacks a quantitative measurement. In this work, a full-field burn depth detection system is proposed using the near-infrared hyperspectral imaging with the ensemble regression. The rotational feature subspace ensemble regression is introduced to establish a complex regression model between the hyperspectral imaging data and the burn depth. By the in vivo measurement of a porcine model, the method can get the average relative error about 7% for the burn depth measurement, which demonstrates that the proposed method can perform an accurate full-field assessment of burn depth and provide more practical references for clinicians.


Assuntos
Queimaduras/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Raios Infravermelhos , Imagem Óptica/métodos , Animais , Masculino , Método de Monte Carlo , Pele/diagnóstico por imagem , Suínos
15.
Neurosci Lett ; 398(3): 291-5, 2006 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-16469439

RESUMO

Stromal cell-derived factor (SDF-1), by activating its cognate receptor CXCR4, plays multiple roles in cell migration, proliferation and survival in the development of the central nervous system. Recently, we have shown that functional SDF1alpha/CXCR4 signaling mediates chemotaxis through extracellular signal-regulated kinase (ERK) activation in the developing spinal cord. Here, we report that SDF1alpha/CXCR4 signaling activates beta-catenin/TCF transcriptional activity in embryonic rat spinal cord neural progenitors. Stimulation of neural progenitors with SDF1alpha resulted in cytoplasmic beta-catenin accumulation in 30 min, and lasted for approximately 240 min, while Wnt3a, a positive control, stabilized cytoplasmic beta-catenin in 120 min. Dose-response studies indicated that the beta-catenin stabilization effect could be detected in cells exposed to fM concentrations of SDF1alpha. This SDF1alpha-induced beta-catenin stabilization effect was inhibited by pretreatment of the cells with either pertussis toxin (PTX), an inactivator of G protein-coupled receptors, or PD98059, a MEK1 inhibitor. Concomitant with beta-catenin accumulation in the cytoplasm, SDF1alpha enhanced nuclear translocation of beta-catenin and its binding to nuclear transcription factor T cell-specific transcription factor/lymphoid enhancer-binding factor (TCF/LEF). Furthermore, SDF1alpha increased expression of genes such as Ccnd1, 2, 3, and c-Myc known as targets of the Wnt/beta-catenin/TCF pathway. The increased expression of Ccnd1 and c-Myc by SDF1alpha was further confirmed by immunoblot analysis. Our data suggest that SDF1alpha/CXCR4 signaling may interact with the Wnt/beta-catenin/TCF pathway to regulate the development of the central nervous system.


Assuntos
Quimiocinas CXC/fisiologia , Neurônios/metabolismo , Células-Tronco/metabolismo , Transcrição Gênica , beta Catenina/fisiologia , Animais , Núcleo Celular/metabolismo , Células Cultivadas , Quimiocina CXCL12 , Citoplasma/metabolismo , Embrião de Mamíferos/citologia , Análise de Sequência com Séries de Oligonucleotídeos , Ligação Proteica , Transporte Proteico , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Medula Espinal/citologia , Fatores de Transcrição TCF/metabolismo , Proteínas Wnt/fisiologia , Proteína Wnt3 , beta Catenina/metabolismo
16.
17.
Rev Sci Instrum ; 87(3): 033109, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27036760

RESUMO

An active phase locking of a large-scale fiber array with thirty channels has been demonstrated experimentally. In the experiment, the first group of thirty phase controllers is used to compensate the phase noises between the elements and the second group of thirty phase modulators is used to impose additional phase disturbances to mimic the phase noises in the high power fiber amplifiers. A multi-level phase dithering algorithm using dual-level rectangular-wave phase modulation and time division multiplexing can achieve the same phase control as single/multi-frequency dithering technique, but without coherent demodulation circuit. The phase locking efficiency of 30 fiber channels is achieved about 98.68%, 97.82%, and 96.50% with no additional phase distortion, modulated phase distortion I (±1 rad), and phase distortion II (±2 rad), corresponding to the phase error of λ/54, λ/43, and λ/34 rms. The contrast of the coherent combined beam profile is about 89%. Experimental results reveal that the multi-level phase dithering technique has great potential in scaling to a large number of laser beams.

18.
Stem Cells Dev ; 14(3): 270-84, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15969622

RESUMO

Human embryonic stem cells (hESC) must be differentiated before clinical use. In addition, the extent of contamination of undifferentiated cells and the efficiency of differentiation must also be assessed prior to clinical application. In this manuscript, we describe the development of a focused microarray that may be used to discriminate between hESC and their differentiated progeny. This array contains 755 genes including embryonic stem cell markers as well as markers of differentiation into neural, mesodermal, and endodermal phenotypes. In addition, we have included candidate genes belonging to families of cytokines, chemokines, receptors, signaling pathways, and homeodomain proteins that are likely to be important in the process of differentiation. Testing and validation of the focused array was performed using RNA from hESC, human embryoid body (hEB) outgrowths, and a human embryonal carcinoma (hEC) cell line. We have compared gene expression with negative background, GAPDH, beta-actin positive controls, and human universal RNA (hURNA), showing that such an array can rapidly distinguish between undifferentiated and differentiated hESC-derived cell populations. We expect that the described array will be extremely useful in evaluating the extent of differentiation and the state of the hESC-derived population utilized for therapeutic purposes.


Assuntos
Diferenciação Celular , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Células-Tronco/citologia , Linhagem Celular , Embrião de Mamíferos , Enzimas/genética , Humanos , Hibridização de Ácido Nucleico , Proteínas/genética , RNA/genética , RNA/isolamento & purificação , Transplante de Células-Tronco , Células-Tronco/fisiologia
19.
J Vis Exp ; (96)2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25741760

RESUMO

Targeted transgene addition can provide persistent gene expression while circumventing the gene silencing and insertional mutagenesis caused by viral vector mediated random integration. This protocol describes a universal and efficient transgene targeted addition platform in human iPSCs based on utilization of validated open-source TALENs and a gene-trap-like donor to deliver transgenes into a safe harbor locus. Importantly, effective gene editing is rate-limited by the delivery efficiency of gene editing vectors. Therefore, this protocol first focuses on preparation of iPSCs for transfection to achieve high nuclear delivery efficiency. When iPSCs are dissociated into single cells using a gentle-cell dissociation reagent and transfected using an optimized program, >50% cells can be induced to take up the large gene editing vectors. Because the AAVS1 locus is located in the intron of an active gene (PPP1R12C), a splicing acceptor (SA)-linked puromycin resistant gene (PAC) was used to select targeted iPSCs while excluding random integration-only and untransfected cells. This strategy greatly increases the chance of obtaining targeted clones, and can be used in other active gene targeting experiments as well. Two weeks after puromycin selection at the dose adjusted for the specific iPSC line, clones are ready to be picked by manual dissection of large, isolated colonies into smaller pieces that are transferred to fresh medium in a smaller well for further expansion and genetic and functional screening. One can follow this protocol to readily obtain multiple GFP reporter iPSC lines that are useful for in vivo and in vitro imaging and cell isolation.


Assuntos
Engenharia Genética/métodos , Células-Tronco Pluripotentes Induzidas/fisiologia , Transfecção/métodos , Eletroporação/métodos , Expressão Gênica , Marcação de Genes/métodos , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Proteína Fosfatase 1/genética , Puromicina/farmacologia , Transgenes
20.
PLoS One ; 10(1): e0116032, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25587899

RESUMO

Targeted genome engineering to robustly express transgenes is an essential methodology for stem cell-based research and therapy. Although designer nucleases have been used to drastically enhance gene editing efficiency, targeted addition and stable expression of transgenes to date is limited at single gene/locus and mostly PPP1R12C/AAVS1 in human stem cells. Here we constructed transcription activator-like effector nucleases (TALENs) targeting the safe-harbor like gene CLYBL to mediate reporter gene integration at 38%-58% efficiency, and used both AAVS1-TALENs and CLYBL-TALENs to simultaneously knock-in multiple reporter genes at dual safe-harbor loci in human induced pluripotent stem cells (iPSCs) and neural stem cells (NSCs). The CLYBL-TALEN engineered cell lines maintained robust reporter expression during self-renewal and differentiation, and revealed that CLYBL targeting resulted in stronger transgene expression and less perturbation on local gene expression than PPP1R12C/AAVS1. TALEN-mediated CLYBL engineering provides improved transgene expression and options for multiple genetic modification in human stem cells.


Assuntos
Endonucleases/genética , Marcação de Genes/métodos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Neurais/citologia , Linhagem Celular , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Neurais/metabolismo , Transgenes/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa