The authors dedicate this paper in honor of Prof. Gilberto Oliveira-Castro who introduced research in intercellular communication by gap junctions in Brazil. This work was funded by Capes, CNPQ and Faperj.

<html> 1. Preparação de células <ol><li> Manter uma cultura de uma linha celular epitelial tímica (IT76M1) ou célula a ser testada numa incubadora (37 ° C / 5% de CO 2). </li><li> Lave as células com PBS 1x (repetir este item 3x). </li><li> Adicionar tripsina às células durante 5 min. </li><li> Adicionar meio (o dobro do volume de tripsina adicionada no ponto 1.3) com 10% de FBS (soro fetal bovino) para as células com tripsina e centrifugação (800 xg durante 5 min). </li><li> Contar as células num hemocitómetro. </li><li> Ajustar a densidade de células de acordo com o tipo de células como as células têm que estar em estreito contacto umas com as outras para permitir o acoplamento. Nota: No nosso caso, usamos 3 x 10 5 células por 35 milímetros placa de Petri. </li></ol> 2. Preparação Micropipeta <ol><li> Puxar a micropipeta, conforme especificado a partir de uma micropipeta capilar de vidro (1,5 mm de diâmetro) para uma final de 0,2 um de diâmetro de modo a atingir uma resistência final de aproximadamente 30 mohmsf &quot;&gt; 17, 18. NOTA: Alternativamente, as pipetas de injecção pode ser comprado. A resistência depende do tamanho da célula, por exemplo, seria necessário para células acinares pancreáticas um microeléctrodo resistência mais elevada, por exemplo (100-150 mohms) 19. Um problema comum é que pode ocorrer a precipitação da solução amarelo Lucifer, que pode, em seguida, obstruir a micropipeta e pode necessitar de filtração ou centrifugação antes. Antes da injecção, a micropipeta devem ser analisadas sob o microscópio para detectar se existe uma obstrução ou qualquer tipo de interrupção 13. A micropipeta pode ser testada através da injecção de LY com a ponta da micropipeta dentro de uma solução salina. </li></ol> 3. Teste a micropipeta <ol><li> Preparar a solução de Amarelo Lúcifer (5%) em 150 mmol / L de LiCl e carregar a micropipeta com uma seringa ou por enchimento (colocar nele LY solução). </li><li> Coloque a micropipette ao longo de 35 mm placa de Petri com as células IT76M1 na estação de trabalho microinjecção e submergir a ponta da micropipeta de vidro para o meio celular. Concentre-se na micropipeta e executar um teste de corante fluindo através da aplicação de um pulso. </li></ol> 4. uma única célula Lucifer Yellow Microinjeção <ol><li> Concentre-se o microscópio logo acima da camada de células usando um grande aumento fi cação (40X) e desça lentamente a pipeta para as células usando o micromanipulador. </li><li> Perfurar a célula alvo quando a ponta está perto o suficiente para tocar a membrana celular, e aplique uma pequena pulsação de hiperpolarização para introduzir o LY na célula. A tensão aplicada dependerá da carga líquida do corante a ser injectada. Alternativamente, alguns outros corantes podem ser usados ​​com esta técnica, como mostrado na Tabela 1. Nota: Em princípio, qualquer corante hidrofílico com um PM inferior a 1 kDa poderia ser usada. No entanto, a taxa de transferência pode variar de acordo com o peso e hidrofilicidade. Além disso, utransferência nspecific do corante utilizado deve ser avaliada. </li><li> Capturar imagens de células 3 min após a injeção de corante ou fazer um pequeno filme com microscopia de lapso de tempo (30 fps). NOTA: Uma abordagem semelhante pode ser visto na Hitomi et al (2015) 20. Para evitar a comunicação por pontes intercelulares (mitose incompleto), um co-injecção de dextrano rodamina (de 2 a 10 kDa), que não passa através de junções de hiato, mas passa através de pontes intercelulares e certos tipos de nanotubules é recomendada como mostrado na Figura 2 . </li></ol>

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The authors have no conflicts of interest.

A fim de verificar a presença de junções de hiato funcionais intercelular, a utilização de marcadores, que são membrana impermeável, embora permeável por meio de canais intercelulares são necessários 16. Fluoresceína, o primeiro corante fluorescente para observar célula-a-célula de acoplamento 22, é permeável entre membranas não juncionais 3 e, por conseguinte, tem sido substituído por Lúcifer corante Amarelo 15.<...

As junções de hiato são canais intercelulares que permitem a intercomunicação entre células vizinhas 1. Esta comunicação conecta duas ou mais células vizinhas, onde cada um contribui com um connexon ou hemichannel para formar o canal intercelular. Em células de mamíferos, o connexon é formado por seis conexinas, monómeros com quatro domínios transmembranares e um terminal de C e N dentro do citoplasma 2. As junções de hiato não só permitir o fluxo de iões, segundos mensageiros e pequenos metabolitos, mas também contribuir para muitas formas de comunicação celular em muitos processos fisiológicos, tais como a transmissão sináptica, a contracção cardíaca, crescimento e diferenciação celular 3, 4, 5, 6, 7, 8. Além disso as junções de hiato foram associados commuitas doenças incluindo cancro 9, 10, 11, atrofia muscular, algumas doenças genéticas e doenças desmielinizantes 12. Este tipo de interferência intercelular pode ser avaliada através de vários métodos 13, 14, 15, 16. Neste artigo, vamos mostrar como realizar uma microinjeção de uma única célula de Lucifer Yellow visualizar comunicação celular via gap-junções em células vivas. Discute-se como preparar as células e a micropipeta, a utilização do micromanipulador e a injecção do corante Amarelo Lúcifer em uma linha de células epiteliais do timo. Normalmente, este procedimento experimental poderia ser analisados ​​pela média de células ligadas à célula carregado com corante. Além disso, este método pode ser usado com outros corantes fluorescentes com peso molecular inferior a lacunajunções de corte, que é cerca de 1.000 daltons.

<table border="0" cellpadding="0" cellspacing="0" width="1228">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">Lucifer yellow</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:137px;">L0259</td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">Lithium Chloride</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:137px;">L4408</td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">PBS tablets</td>
			<td style="width:71px;">Sigma&#160;</td>
			<td style="width:137px;">P4417</td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">RPMI</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:137px;">R4130</td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">Bovine fetal serum</td>
			<td style="width:71px;">Cultilab</td>
			<td style="width:137px;"></td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">Trypsin</td>
			<td style="width:71px;">Sigma</td>
			<td style="width:137px;">T4799</td>
			<td style="width:827px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microscope</td>
			<td style="width:71px;">Nikon</td>
			<td style="width:137px;">TE-2000</td>
			<td>For microinjection experiments, one needs an inverted fluorescence microscope and &#64257;lters for &#64258;uorescent microscopy</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">vibration-insulated table&#160;</td>
			<td style="width:71px;">Newport</td>
			<td style="width:137px;">VH3036W-OPT</td>
			<td>A vibration-insulated table is needed to protect the experiments from vibration and avoid cell damage</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micromanipulator</td>
			<td style="width:71px;">Narishige</td>
			<td style="width:137px;">MMO-203</td>
			<td>This equipment allows precision adjustments of the micropipette, which is needed for cell micro injection.</td>
		</tr>
		<tr height="100">
			<td height="100" style="height:100px;">Current Generator&#160;</td>
			<td style="width:71px;">Digitimer</td>
			<td style="width:137px;">DS2</td>
			<td>To produce the dye flow through the micropipette, a current below one nano ampere was given using a current generator with an electrode inside the micropipette or an amplifier which has a capacitance compensation circuit (old electrometer) or current injection functions of new patch clamp amplifiers, and the ground wire submersed in the plate dish. Alternatively, the dye can be injected by a pneumatic microinjector, following the factory recommendations.&#160;&#160;&#160;</td>
		</tr>
	</tbody>
</table>

single-cell microinjection for cell communication analysis

Gap junctions are intercellular channels that allow the communication of neighboring cells. This communication depends on the contribution of a hemichannel by each neighboring cell to form the gap junction. In mammalian cells, the hemichannel is formed by six connexins, monomers with four transmembrane domains and a C and N terminal within the cytoplasm. Gap junctions permit the exchange of ions, second messengers, and small metabolites. In addition, they have important roles in many forms of cellular communication within physiological processes such as synaptic transmission, heart contraction, cell growth and differentiation. We detail how to perform a single-cell microinjection of Lucifer Yellow to visualize cellular communication via gap-junctions in living cells. It is expected that in functional gap junctions, the dye will diffuse from the loaded cell to the connected cells. It is a very useful technique to study gap junctions since you can evaluate the diffusion of the fluorescence in real time. We discuss how to prepare the cells and the micropipette, how to use a micromanipulator and inject a low molecular weight fluorescent dye in an epithelial cell line.

Tímico linha celular epitelial de TI-76MI foram usadas para avaliar corante de acoplamento por junções de hiato como estas células foram descritos para expressar junções de hiato funcionais formados por conexina 43 21. A Figura 1 mostra a injecção de Amarelo Lúcifer quando aplicado na uma célula abaixo da ponta da pipeta. Após alguns minutos, as células tornam-se ligados fluorescente (asteriscos), indicando a difusão do corante fluorescente através d...

Watch this Scientific Journal Video about Single-cell Microinjection for Cell Communication Analysis at JoVE.com

Single-cell Microinjection for Cell Communication Analysis

Descrevemos aqui como executar uma microinjeção de uma única célula de Lucifer Yellow visualizar comunicação celular via gap-junções em células vivas, e fornecer algumas dicas úteis. Esperamos que este trabalho irá ajudar a todos para avaliar o grau de acoplamento celular devido à junções comunicantes funcionais. Tudo o descrito aqui pode ser, em princípio, adaptado para outros corantes fluorescentes com peso molecular inferior a 1.000 Daltons.

Microinjeção de uma única célula para análise da comunicação celular

Gap junctions are intercellular channels that allow the communication of neighboring cells. This communication depends on the contribution of a ...

single-cell-microinjection-for-cell-communication-analysis

Research

JoVE Journal

Biology

11.2K visualizações.  Oswaldo Cruz Foundation.  Descrevemos aqui como executar uma microinjeção de uma única célula de Lucifer Yellow visualizar comunicação celular via gap-junções em células vivas, e fornecer algumas dicas úteis. Esperamos que este trabalho irá ajudar a todos para avaliar o grau de acoplamento celular devido à junções comunicantes funcionais. Tudo o descrito aqui pode ser, em princípio, adaptado para outros corantes fluorescentes com peso molecular inferior a 1.000 Daltons. 

Vídeo: Single-cell Microinjection for Cell Communication Analysis

Single Cell Transfection in Chick Embryos

A central theme in developmental biology is the diversification of lineages and the elucidation of underlying molecular mechanisms. This entails a thorough analysis of the fates of single cells under normal and experimental conditions. To this end, transfection methods that target single progenitors are a prerequisite. We describe here a technically straightforward method for transfecting single cells in chicken tissues in-ovo, allowing reliable lineage tracing as well as genetic manipulation. Specific tissue domains are targeted within the somite or neural tube, and DNA is injected directly into the epithelium of interest, resulting in sporadic transfection of single cells. Using reporters, clonal populations may consequently be traced for up to three days, and behavior of genetically manipulated clonal populations can be compared with that of controls. This method takes advantage of the accessibility of the chick embryo along with emerging tools for genetic manipulation. We compare and discuss its advantages over the widely-used electroporation method, and possible applications and use in additional in-vivo models are also suggested. We advocate the use of this method as a significant addition and complement for existing lineage tracing and genetic interference tools.

Using fine tip micropipettes we inject plasmid DNA into subdomains of chicken somites or neural tubes. The concentration of the plasmid is adjusted to generate single transfected cells. We then allow the cells to develop into clonal populations.

Transfecção única célula em embriões de galinha

A central theme in developmental biology is the diversification of lineages and the elucidation of underlying molecular mechanisms. This entails a ...

Biologia

Single Cell Fate Mapping in Zebrafish

The ability to differentially label single cells has important implications in developmental biology. For instance, determining how hematopoietic, lymphatic, and blood vessel lineages arise in developing embryos requires fate mapping and lineage tracing of undifferentiated precursor cells. Recently, photoactivatable proteins which include: Eos1, 2, PAmCherry3, Kaede4-7, pKindling8, and KikGR9, 10 have received wide interest as cell tracing probes. The fluorescence spectrum of these photosensitive proteins can be easily converted with UV excitation, allowing a population of cells to be distinguished from adjacent ones. However, the photoefficiency of the activated protein may limit long-term cell tracking11. As an alternative to photoactivatable proteins, caged fluorescein-dextran has been widely used in embryo model systems7, 12-14. Traditionally, to uncage fluorescein-dextran, UV excitation from a fluorescence lamp house or a single photon UV laser has been used; however, such sources limit the spatial resolution of photoactivation. Here we report a protocol to fate map, lineage trace, and detect single labeled cells. Single cells in embryos injected with caged fluorescein-dextran are photoactivated with near-infrared laser pulses produced from a titanium sapphire femtosecond laser. This laser is customary in all two-photon confocal microscopes such as the LSM 510 META NLO microscope used in this paper. Since biological tissue is transparent to near-infrared irradiation15, the laser pulses can be focused deep within the embryo without uncaging cells above or below the selected focal plane. Therefore, non-linear two-photon absorption is induced only at the geometric focus to uncage fluorescein-dextran in a single cell. To detect the cell containing uncaged fluorescein-dextran, we describe a simple immunohistochemistry protocol16 to rapidly visualize the activated cell. The activation and detection protocol presented in this paper is versatile and can be applied to any model system. 
Note: The reagents used in this protocol can be found in the table appended at the end of the article.

A method is described to photoactivate single cells containing a caged fluorescent protein using two-photon absorption from a Ti:Sapphire femtosecond laser oscillator. To fate map the photoactivated cell, immunohistochemistry is used. This technique can be applied to any cell type.

Mapeamento Destino única célula em Zebrafish

The ability to differentially label single cells has important implications in developmental biology. For instance, determining how hematopoietic, ...

Single Cell Transcriptional Profiling of Adult Mouse Cardiomyocytes

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation between cells within a tissue. Isolation of pure cardiomyocyte populations through a collagenase perfusion of mouse hearts facilitates the generation of single cell microarrays for whole transcriptome gene expression, or qPCR of specific targets using nanofluidic arrays. We describe here a procedure to examine single cell gene expression profiles of cardiomyocytes isolated from the heart. This paradigm allows for the evaluation of metrics of interest which are not reliant on the mean (for example variance between cells within a tissue) which is not possible when using conventional whole tissue workflows for the evaluation of gene expression (Figure 1). We have achieved robust amplification of the single cell transcriptome yielding micrograms of double stranded cDNA that facilitates the use of microarrays on individual cells. In the procedure we describe the use of NimbleGen arrays which were selected for their ease of use and ability to customize their design. Alternatively, a reverse transcriptase - specific target amplification (RT-STA) reaction, allows for qPCR of hundreds of targets by nanofluidic PCR. Using either of these approaches, it is possible to examine the variability of expression between cells, as well as examining expression profiles of rare cell types from within a tissue. Overall, the single cell gene expression approach allows for the generation of data that can potentially identify idiosyncratic expression profiles that are typically averaged out when examining expression of millions of cells from typical homogenates generated from whole tissues.

Single cell expression profiling allows the detailed gene expression analysis of individual cells. We describe methods for the isolation of cardiomyocytes, and preparing the resulting lysates for either whole transcriptome microarray or qPCR of specific targets.

Profiling única célula transcricional dos cardiomiócitos de rato adulto

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation ...

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization (FISH)

Adhesion of Plasmodium falciparum infected erythrocytes (IE) to human endothelial receptors during malaria infections is mediated by expression of PfEMP1 protein variants encoded by the var genes.
The haploid P. falciparum genome harbors approximately 60 different var genes of which only one has been believed to be transcribed per cell at a time during the blood stage of the infection. How such mutually exclusive regulation of var gene transcription is achieved is unclear, as is the identification of individual var genes or sub-groups of var genes associated with different receptors and the consequence of differential binding on the clinical outcome of P. falciparum infections. Recently, the mutually exclusive transcription paradigm has been called into doubt by transcription assays based on individual P. falciparum transcript identification in single infected erythrocytic cells using RNA fluorescent in situ hybridization (FISH) analysis of var gene transcription by the parasite in individual nuclei of P. falciparum IE1.
Here, we present a detailed protocol for carrying out the RNA-FISH methodology for analysis of var gene transcription in single-nuclei of P. falciparum infected human erythrocytes. The method is based on the use of digoxigenin- and biotin- labeled antisense RNA probes using the TSA Plus Fluorescence Palette System2 (Perkin Elmer), microscopic analyses and freshly selected P. falciparum IE. The in situ hybridization method can be used to monitor transcription and regulation of a variety of genes expressed during the different stages of the P. falciparum life cycle and is adaptable to other malaria parasite species and other organisms and cell types.

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization FISH

Fluorescent in situ hybridization (FISH) to identify mRNA transcripts in individual cells allows analysis of polygenic activity such as the simultaneous transcription of more than one member of the var multigene family in Plasmodium falciparum infected erythrocytes 1. The technique is adaptable and can be used on different types of genes, cells and organisms.

Análise de uma única célula de transcrição do gene pela RNA Fluorescente<em&gt; In Situ</em&gt; A hibridização (FISH)

Adhesion of Plasmodium falciparum infected erythrocytes (IE) to human endothelial receptors during malaria infections is mediated by expression of PfEMP1 ...

Analysis of Global RNA Synthesis at the Single Cell Level following Hypoxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a particular transcriptional program in order to mount an appropriate and coordinated cellular response. The cell possesses several oxygen sensor enzymes that require molecular oxygen as cofactor for their activity. These range from prolyl-hydroxylases to histone demethylases. The majority of studies analyzing cellular responses to hypoxia are based on cellular populations and average studies, and as such single cell analysis of hypoxic cells are seldom performed. Here we describe a method of analysis of global RNA synthesis at the single cell level in hypoxia by using Click-iT RNA imaging kits in an oxygen controlled workstation, followed by microscopy analysis and quantification.&nbsp; Using cancer cells exposed to hypoxia for different lengths of time, RNA is labeled and measured in each cell. This analysis allows the visualization of temporal and cell-to-cell changes in global RNA synthesis following hypoxic stress.

We describe a technique for analysis of global RNA synthesis in hypoxia using imaging. Click-chemistry labeling of RNA has not previously been performed under hypoxia and allows visualization of global RNA changes at the single cell level. This approach complements the existing averaged RNA techniques, allowing direct visualization of cell-to-cell changes in global RNA synthesis.

Análise da Global RNA Síntese no nível da célula única seguinte hipóxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a ...

Single-cell Microfluidic Analysis of Bacillus subtilis

Microfluidic technology overcomes many of the limitations to traditional analytical methods in microbiology. Unlike bulk-culture methods, it offers single-cell resolution and long observation times spanning hundreds of generations; unlike agarose pad-based microscopy, it has uniform growth conditions that can be tightly controlled. Because the continuous flow of growth medium isolates the cells in a microfluidic device from unpredictable variations in the local chemical environment caused by cell growth and metabolism, authentic changes in gene expression and cell growth in response to specific stimuli can be more confidently observed. Bacillus subtilis is used here as a model bacterial species to demonstrate a &#34;mother machine&#34;-type method for cellular analysis. We show how to construct and plumb a microfluidic device, load it with cells, initiate microscopic imaging, and expose cells to a stimulus by switching from one growth medium to another. A stress-responsive reporter is used as an example to reveal the type of data that may be obtained by this method. We also briefly discuss further applications of this method for other types of experiments, such as analysis of bacterial sporulation.

Single-cell Microfluidic Analysis of Bacillus subtilis

We present a method for the microfluidic analysis of individual bacterial cell lineages using Bacillus subtilis as an example. The method overcomes shortcomings of traditional analytical methods in microbiology by allowing observation of hundreds of cell generations under tightly controllable and uniform growth conditions.

Célula única Microfluidic análise de Bacillus subtilis

Microfluidic technology overcomes many of the limitations to traditional analytical methods in microbiology. Unlike bulk-culture methods, it offers ...

Analysis of Beta-cell Function Using Single-cell Resolution Calcium Imaging in Zebrafish Islets

Pancreatic beta-cells respond to increasing blood glucose concentrations by secreting the hormone insulin. The dysfunction of beta-cells leads to hyperglycemia and severe, life-threatening consequences. Understanding how the beta-cells operate under physiological conditions and what genetic and environmental factors might cause their dysfunction could lead to better treatment options for diabetic patients. The ability to measure calcium levels in beta-cells serves as an important indicator of beta-cell function, as the influx of calcium ions triggers insulin release. Here we describe a protocol for monitoring the glucose-stimulated calcium influx in zebrafish beta-cells by using GCaMP6s, a genetically encoded sensor of calcium. The method allows monitoring the intracellular calcium dynamics with single-cell resolution in ex vivo mounted islets. The glucose-responsiveness of beta-cells within the same islet can be captured simultaneously under different glucose concentrations, which suggests the presence of functional heterogeneity among zebrafish beta-cells. Furthermore, the technique provides high temporal and spatial resolution, which reveals the oscillatory nature of the calcium influx upon glucose stimulation. Our approach opens the doors to use the zebrafish as a model to investigate the contribution of genetic and environmental factors to beta-cell function and dysfunction.

Beta-cell functionality is important for blood-glucose homeostasis, which is evaluated at single-cell resolution using a genetically encoded reporter for calcium influx.

Análise da função de células Beta utilizando imagens de cálcio de célula única resolução em ilhotas de Zebrafish

Pancreatic beta-cells respond to increasing blood glucose concentrations by secreting the hormone insulin. The dysfunction of beta-cells leads to ...

Single-Cell Resolution Three-Dimensional Imaging of Intact Organoids

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development and function as well as disease. Fluorescence microscopy has played a major role in characterizing their cellular composition in detail and demonstrating their similarity to the tissue they originate from. In this article, we present a comprehensive protocol for high-resolution 3D imaging of whole organoids upon immunofluorescent labeling. This method is widely applicable for imaging of organoids differing in origin, size and shape. Thus far we have applied the method to airway, colon, kidney, and liver organoids derived from healthy human tissue, as well as human breast tumor organoids and mouse mammary gland organoids. We use an optical clearing agent, FUnGI, which enables the acquisition of whole 3D organoids with the opportunity for single-cell quantification of markers. This three-day protocol from organoid harvesting to image analysis is optimized for 3D imaging using confocal microscopy.

The entire 3D structure and cellular content of organoids, as well as their phenotypic resemblance to the original tissue can be captured using the single-cell resolution 3D imaging protocol described here. This protocol can be applied to a wide range of organoids varying in origin, size and shape.

Resolução unicelular imagens tridimensionais de organoides intactos

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development ...

Real-Time Detection of Reactive Oxygen Species Production in Immune Response in Rice with a Chemiluminescence Assay

Reactive oxygen species (ROS) play vital roles in a variety of biological processes, including the sensing of abiotic and biotic stresses. Upon pathogen infection or challenge with pathogen-associated chemicals (pathogen-associated molecular patterns [PAMPs]), an array of immune responses, including a ROS burst, are quickly induced in plants, which is called PAMP-triggered immunity (PTI). A ROS burst is a hallmark PTI response, which is catalyzed by a group of plasma membrane-localized NADPH oxidases-the RBOH family proteins. The vast majority of ROS comprise hydrogen peroxide (H2O2), which can be easily and steadily detected by a luminol-based chemiluminescence method. Chemiluminescence is a photon-producing reaction in which luminol, or its derivative (such as L-012), undergoes a redox reaction with ROS under the action of a catalyst. This paper describes an optimized L-012-based chemiluminescence method to detect apoplast ROS production in real-time upon PAMP elicitation in rice tissues. The method is easy, steady, standardized, and highly reproducible under firmly controlled conditions.

Here, we describe a method for the real-time detection of apoplastic reactive oxygen species (ROS) production in rice tissues in pathogen-associated molecular pattern-triggered immune response. This method is simple, standardized, and generates highly reproducible results under controlled conditions.

Detecção em Tempo Real da Produção de Espécies Reativas de Oxigênio na Resposta Imune em Arroz com Ensaio de Quimioluminescência

Reactive oxygen species (ROS) play vital roles in a variety of biological processes, including the sensing of abiotic and biotic stresses. Upon pathogen ...

Single-Cell Proteomics Preparation for Mass Spectrometry Analysis Using Freeze-Heat Lysis and an Isobaric Carrier

Single-cell proteomics analysis requires sensitive, quantitatively accurate, widely accessible, and robust methods. To meet these requirements, the Single-Cell ProtEomics (SCoPE2) protocol was developed as a second-generation method for quantifying hundreds to thousands of proteins from limited samples, down to the level of a single cell. Experiments using this method have achieved quantifying over 3,000 proteins across 1,500 single mammalian cells (500-1,000 proteins per cell) in 10 days of mass spectrometer instrument time. SCoPE2 leverages a freeze-heat cycle for cell lysis, obviating the need for clean-up of single cells and consequently reducing sample losses, while expediting sample preparation and simplifying its automation. Additionally, the method uses an isobaric carrier, which aids protein identification and reduces sample losses.
This video protocol provides detailed guidance to enable the adoption of automated single-cell protein analysis using only equipment and reagents that are widely accessible. We demonstrate critical steps in the procedure of preparing single cells for proteomic analysis, from harvesting up to injection to liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Additionally, viewers are guided through the principles of experimental design with the isobaric carrier, quality control for both isobaric carrier and single-cell preparations, and representative results with a discussion of limitations of the approach.

In this protocol, we describe how to prepare mammalian cells for single-cell proteomics analysis via mass spectrometry using commercially available reagents and equipment, with options for both manual and automatic pipetting.

Preparação de Proteômica de Célula Única para Análise de Espectrometria de Massa usando Lise de Calor Congelante e um Transportador Isobárico

Single-cell proteomics analysis requires sensitive, quantitatively accurate, widely accessible, and robust methods. To meet these requirements, the ...