Este estudio fue apoyado por el Programa de Investigación Intramural de los Institutos Nacionales de Salud, Instituto Nacional sobre el Envejecimiento. Los autores desean agradecer a Myriam Gorospe y Kotb Abdelmohsen útil para muchos debates sobre la senescencia y Kotb Abdelmohsen para también la lectura crítica del manuscrito. Agradecemos también a los miembros de nuestro laboratorio, especialmente Douglas Dluzen para la lectura crítica del manuscrito.

Los autores no tienen nada que revelar.

Aquí, hemos descrito métodos para replicativa y daño de ADN inducido por senescencia utilizando fibroblastos diploides humanos. Además, las técnicas para la cuantificación de proteínas y niveles de ARNm de varias proteínas de la senescencia asociado se incluyen, así como tinción para SA-β-gal y para el marcador de daño de ADN γ-H2AX. Estos protocolos pueden ser ampliamente utilizados para evaluar fenotipos senescentes tanto in vitro como in vivo, aunque existen muchas advertencias para la ...

Hace más de medio siglo, Hayflick y sus colegas describen cómo las células no transformadas proliferen en cultivo, pero sólo durante un periodo finito de tiempo 1. el cultivo a largo plazo de fibroblastos humanos hizo que las células para detener la proliferación; sin embargo, eran metabólicamente activa, y esto fue llamado senescencia celular. La senescencia puede ser beneficioso para la inhibición de la tumorigénesis, pero también puede ser perjudicial, ya que se cree que contribuyen a la pérdida de capacidad de regeneración que se produce con el envejecimiento 2, 3. Las células senescentes se han demostrado que se acumulan en los tejidos como humanos 4 edad y han sido implicados en una serie de procesos biológicos, incluyendo el desarrollo embrionario, la cicatrización de heridas, reparación de tejidos, y la inflamación 2 relacionada con la edad. passaging continua de las células en cultivo induce senescencia replicativa, que se ha relacionadoa telómero desgaste y la inestabilidad genómica. Diversas tensiones de células, incluyendo daño en el ADN y oncogenes, también pueden causar la senescencia 3. La senescencia causado por factores distintos de desgaste de los telómeros se llama a menudo inducida por el estrés o la senescencia prematura y generalmente depende de la INK4A p16 / Rb ruta de la 5. Aunque la proliferación, las células no transformadas aparecen típicamente husillo en forma, las células senescentes pueden ser identificados como que tiene ciertas características, incluyendo una, gran morfología plana y aumento de la actividad β-galactosidasa asociada a la senescencia (SA-β-gal) (Figuras 1 y 2). Las células senescentes también se acumulan marcadores de daño de ADN, incluyendo γ-H2AX (Figura 3) 6, y, potencialmente, asociada a la senescencia heterocromatina focos (SAHF) (Figura 4) 7. Las células senescentes tienen mayores niveles de los reguladores del ciclo celular, incluyendo p<html> 16 (INK4A p16) y / o p21 y p53 (Figura 5) 8, 9. Además, datos recientes han demostrado que las células senescentes pueden tener efectos no autónomos mediante la secreción de una serie de citocinas y quimiocinas pro-inflamatoria llamada la asociada a la senescencia secretora fenotipo (SASP) 10. Aunque este fenómeno SASP puede variar de tipo celular a tipo celular, en general, se demuestra por un aumento de la interleucina-6 (IL-6), IL-8, factor estimulante de colonias de granulocitos y macrófagos (GM-CSF), crecimiento- α regulado oncogén (GRO-α), y GRO-β, entre otros (Figura 6). El estrés o daño particular que induce la senescencia también pueden influir en el fenotipo secretor 11, 12, 13. SASP puede ser detectado mediante la medición de los niveles de proteínas secretadas utilizando ELISAs o matrices citoquina / proteínas = &quot;xref&quot;&gt; 10, 14. Aunque los mecanismos post-transcripcionales pueden regular los niveles de proteína SASP 11, 15, 16, 17, los cambios en los niveles de mRNA también pueden detectarse en muchos casos. Estos cambios son generalmente más sensibles y más fácil de cuantificar que las mediciones de nivel de proteínas. Otros marcadores senescentes también pueden ser evaluados, incluyendo persistente daño en el ADN focos nucleares, denominados segmentos de ADN con alteraciones de la cromatina de refuerzo senescencia (DNA-cicatrices) 18, y diversos otros marcadores 3, 19, 20. A continuación, describimos técnicas comunes para la inducción de la senescencia en células en cultivo y también para la medición de varios marcadores de senescencia, incluyendo SA-β-Gal, γ-H2AX, SAHF, y la proteína y ARNm de senescenciamoléculas NCE-asociado.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
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		<tr>
			<td>16% Tris-glycine gels</td>
			<td>Invitrogen</td>
			<td colspan="2">XP00160BOX</td>
		</tr>
		<tr>
			<td>Acid-Phenol ChCl3</td>
			<td>Ambion</td>
			<td>AM9720</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa-Fluor 568 goat anti-mouse antibody</td>
			<td>Invitrogen</td>
			<td>A11031</td>
			<td>1:300 dilution</td>
		</tr>
		<tr>
			<td>Cell lifters</td>
			<td>Corning Inc.</td>
			<td>3008</td>
			<td>Cell scraper</td>
		</tr>
		<tr>
			<td>ECL anti-mouse HRP linked antibody</td>
			<td>Amersham</td>
			<td>NA931V</td>
			<td></td>
		</tr>
		<tr>
			<td>ECL Plus Western Blotting Substrate</td>
			<td>Pierce</td>
			<td>32132</td>
			<td>ECL</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Molecular Probes</td>
			<td>MP01306</td>
			<td>stock 5 mg/ml in dH2O</td>
		</tr>
		<tr>
			<td>GAPDH antibody</td>
			<td>Santa Cruz</td>
			<td>sc-32233</td>
			<td>1:1,000-5,000 dilution</td>
		</tr>
		<tr>
			<td>GlycoBlue</td>
			<td>Ambion</td>
			<td>AM9515</td>
			<td></td>
		</tr>
		<tr>
			<td>Histone H3 dimethyl K9 monoclonal antibody</td>
			<td>Abcam</td>
			<td>1220</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>Human IL-6 Quantikine ELISA assay</td>
			<td>R&#38;D systems</td>
			<td>D6050</td>
			<td></td>
		</tr>
		<tr>
			<td>Human IL-8 Quantikine ELISA assay</td>
			<td>R&#38;D systems</td>
			<td>D8000C</td>
			<td></td>
		</tr>
		<tr>
			<td>Human GROa Quantikine ELISA assay</td>
			<td>R&#38;D systems</td>
			<td>DRG00</td>
			<td></td>
		</tr>
		<tr>
			<td>N-N-dimethylformamide&#160;</td>
			<td>Sigma</td>
			<td>D4551</td>
			<td>DMF</td>
		</tr>
		<tr>
			<td>p16 monoclonal antibody</td>
			<td>BD Biosciences</td>
			<td>51-1325gr</td>
			<td>1:500 dilution</td>
		</tr>
		<tr>
			<td>p21 monoclonal antibody</td>
			<td>Millipore</td>
			<td>05-345</td>
			<td>1:750 dilution</td>
		</tr>
		<tr>
			<td>p53 monoclonal antibody</td>
			<td>Santa Cruz</td>
			<td>sc-126</td>
			<td>1:500 dilution clone DO-1</td>
		</tr>
		<tr>
			<td>phospho-H2AX (Ser139) FITC conjugate antibody</td>
			<td>Cell Signaling</td>
			<td>9719</td>
			<td>1:2000 dilution</td>
		</tr>
		<tr>
			<td>POWER SYBR-green PCR master mix&#160;</td>
			<td>Applied Biosystems</td>
			<td>4367659</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-stained molecular weight markers</td>
			<td>Biorad</td>
			<td>161-0374</td>
			<td></td>
		</tr>
		<tr>
			<td>ProLong Gold Antifade&#160;</td>
			<td>Invitrogen</td>
			<td>P36930</td>
			<td></td>
		</tr>
		<tr>
			<td>PVDF membrane&#160;</td>
			<td>Thermo Scientific</td>
			<td>88518</td>
			<td></td>
		</tr>
		<tr>
			<td>Senescence b-Galactosidase Staining Kit</td>
			<td>Cell Signaling</td>
			<td>9860</td>
			<td></td>
		</tr>
		<tr>
			<td>TRIzol</td>
			<td>Ambion/Life Tech</td>
			<td>10296028</td>
			<td></td>
		</tr>
	</tbody>
</table>

techniques to induce and quantify cellular senescence

En respuesta a estrés celular o daño, las células proliferantes pueden inducir un programa específico que inicia un estado de detención del ciclo celular a largo plazo, denominado senescencia celular. La acumulación de células senescentes se produce con el envejecimiento del organismo y por medio de cultivo continuo in vitro. Las células senescentes influyen en muchos procesos biológicos, incluyendo el desarrollo embrionario, la reparación de tejidos y la regeneración, la supresión de tumores, y el envejecimiento. Características de las células senescentes incluyen, pero no se limitan a, aumento de la actividad β-galactosidasa asociada a la senescencia (SA-β-gal); INK4a p16, p53, y p21 niveles; mayores niveles de daño del ADN, incluyendo γ-H2AX; la formación de asociada a senescencia heterocromatina Foci (SAHF); y la adquisición de un fenotipo secretor asociada a la senescencia (SASP), un fenómeno que se caracteriza por la secreción de una serie de citoquinas pro-inflamatorias y moléculas de señalización. A continuación, describimos los protocolos para ambos replicativa ysenescencia daño en el DNA inducida en células cultivadas. Además, destacamos técnicas para controlar el fenotipo senescente utilizando varios marcadores asociados con la senescencia, incluyendo SA-β-gal, γ-H2AX y tinción SAHF, y para cuantificar los niveles de proteína y ARNm de reguladores del ciclo celular y factores de SASP. Estos métodos se pueden aplicar a la evaluación de la senescencia en varios modelos y tejidos.

Las figuras 2 - 6 muestran resultados representativos de tinción SA-β-gal; tinción de γ-H2AX y SAHF; evaluación de los niveles de proteína de p16 INK4a, p21, y p53; y el ARNm y los niveles de proteína de moléculas-senescentes asociado. Aumento de la tinción SA-β-gal se produce con replicativa y daño en el DNA inducido por senescencia. También, observar los cambios morfológicos que se producen con la senescencia. Las células se agrandan y plana en...

Watch this Scientific Journal Video about Techniques to Induce and Quantify Cellular Senescence at JoVE.com

Techniques to Induce and Quantify Cellular Senescence

La senescencia celular, el estado irreversible de la detención del ciclo celular, puede ser inducida por diferentes tipos de estrés celular. A continuación, describimos protocolos para inducir senescencia y métodos celular para evaluar marcadores de senescencia.

Técnicas para inducir la senescencia celular y cuantificar

In response to cellular stress or damage, proliferating cells can induce a specific program that initiates a state of long-term cell-cycle arrest, termed ...

techniques-to-induce-and-quantify-cellular-senescence

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Unit 2

Cell Proliferation

SCIENTISTS IN ACTION

32.9K vistas.  National Institute on Aging, National Institutes of Health.  La senescencia celular, el estado irreversible de la detención del ciclo celular, puede ser inducida por diferentes tipos de estrés celular. A continuación, describimos protocolos para inducir senescencia y métodos celular para evaluar marcadores de senescencia. 

Video: Techniques to Induce and Quantify Cellular Senescence

BioMEMS and Cellular Biology: Perspectives and Applications

The ability to culture cells has revolutionized hypothesis testing in basic cell and molecular biology research. It has become a standard methodology in drug screening, toxicology, and clinical assays, and is increasingly used in regenerative medicine. However, the traditional cell culture methodology   essentially consisting of the immersion of a large population of cells in a homogeneous fluid medium and on a homogeneous flat substrate   has become increasingly limiting both from a fundamental and practical perspective. Microfabrication technologies have enabled researchers to design, with micrometer control, the biochemical composition and topology of the substrate, and the medium composition, as well as the neighboring cell type in the surrounding cellular microenvironment. Additionally, microtechnology is conceptually well-suited for the development of fast, low-cost in vitro systems that allow for high-throughput culturing and analysis of cells under large numbers of conditions. In this interview, Albert Folch explains these limitations, how they can be overcome with soft lithography and microfluidics, and describes some relevant examples of research in his lab and future directions.

BioMEMS y Biología Celular: Perspectivas y Aplicaciones

The ability to culture cells has revolutionized hypothesis testing in basic cell and molecular biology research. It has become a standard methodology in ...

Investigación

Biología

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of the Drosophila melanogaster syncytial embryo for studying mitosis1. Drosophila has useful genetics with a sequenced genome, and it can be easily maintained and manipulated. Many mitotic mutants exist, and transgenic flies expressing functional fluorescently (e.g. GFP) - tagged mitotic proteins have been and are being generated. Targeted gene expression is possible using the GAL4/UAS system2. 

The Drosophila early embryo carries out multiple mitoses very rapidly (cell cycle duration, &asymp;10 min). It is well suited for imaging mitosis, because during cycles 10-13, nuclei divide rapidly and synchronously without intervening cytokinesis at the surface of the embryo in a single monolayer just underneath the cortex. These rapidly dividing nuclei probably use the same mitotic machinery as other cells, but they are optimized for speed; the checkpoint is generally believed to not be stringent, allowing the study of mitotic proteins whose absence would cause cell cycle arrest in cells with a strong checkpoint. Embryos expressing GFP labeled proteins or microinjected with fluorescently labeled proteins can be easily imaged to follow live dynamics (Fig. 1). In addition, embryos can be microinjected with function-blocking antibodies or inhibitors of specific proteins to study the effect of the loss or perturbation of their function3. These reagents can diffuse throughout the embryo, reaching many spindles to produce a gradient of concentration of inhibitor, which in turn results in a gradient of defects comparable to an allelic series of mutants. Ideally, if the target protein is fluorescently labeled, the gradient of inhibition can be directly visualized4. It is assumed that the strongest phenotype is comparable to the null phenotype, although it is hard to formally exclude the possibility that the antibodies may have dominant effects in rare instances, so rigorous controls and cautious interpretation must be applied. Further away from the injection site, protein function is only partially lost allowing other functions of the target protein to become evident.

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of microinjection and high resolution imaging in the Drosophila melanogaster syncytial embryo to study mitosis.

Técnicas de microinyección para el estudio de la mitosis en el Drosophila melanogaster Embrión sincitial

This protocol describes the use of the Drosophila melanogaster syncytial embryo  for studying mitosis1.  Drosophila has useful genetics with a sequenced ...

Imaging Mismatch Repair and Cellular Responses to DNA Damage in Bacillus subtilis

Both prokaryotes and eukaryotes respond to DNA damage through a complex set of physiological changes. Alterations in gene expression, the redistribution of existing proteins, and the assembly of new protein complexes can be stimulated by a variety of DNA lesions and mismatched DNA base pairs. Fluorescence microscopy has been used as a powerful experimental tool for visualizing and quantifying these and other responses to DNA lesions and to monitor DNA replication status within the complex subcellular architecture of a living cell. Translational fusions between fluorescent reporter proteins and components of the DNA replication and repair machinery have been used to determine the cues that target DNA repair proteins to their cognate lesions in vivo and to understand how these proteins are organized within bacterial cells. In addition, transcriptional and translational fusions linked to DNA damage inducible promoters have revealed which cells within a population have activated genotoxic stress responses. In this review, we provide a detailed protocol for using fluorescence microscopy to image the assembly of DNA repair and DNA replication complexes in single bacterial cells. In particular, this work focuses on imaging mismatch repair proteins, homologous recombination, DNA replication and an SOS-inducible protein in Bacillus subtilis. All of the procedures described here are easily amenable for imaging protein complexes in a variety of bacterial species.

Imaging Mismatch Repair and Cellular Responses to DNA Damage in Bacillus subtilis

A detailed protocol is described for imaging the real time formation of DNA repair complexes in Bacillus subtilis cells.

Imágenes de reparación del ADN y la respuesta celular al daño del ADN en Bacillus subtilis</em

Both prokaryotes and eukaryotes respond to DNA damage through a complex set of physiological changes. Alterations in gene expression, the redistribution ...

Aseptic Laboratory Techniques: Plating Methods

Microorganisms are present on all inanimate surfaces creating ubiquitous sources of possible contamination in the laboratory. Experimental success relies on the ability of a scientist to sterilize work surfaces and equipment as well as prevent contact of sterile instruments and solutions with non-sterile surfaces. Here we present the steps for several plating methods routinely used in the laboratory to isolate, propagate, or enumerate microorganisms such as bacteria and phage. All five methods incorporate aseptic technique, or procedures that maintain the sterility of experimental materials. Procedures described include (1) streak-plating bacterial cultures to isolate single colonies, (2) pour-plating and (3) spread-plating to enumerate viable bacterial colonies, (4) soft agar overlays to isolate phage and enumerate plaques, and (5) replica-plating to transfer cells from one plate to another in an identical spatial pattern. These procedures can be performed at the laboratory bench, provided they involve non-pathogenic strains of microorganisms (Biosafety Level 1, BSL-1). If working with BSL-2 organisms, then these manipulations must take place in a biosafety cabinet. Consult the most current edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) as well as Material Safety Data Sheets (MSDS) for Infectious Substances to determine the biohazard classification as well as the safety precautions and containment facilities required for the microorganism in question. Bacterial strains and phage stocks can be obtained from research investigators, companies, and collections maintained by particular organizations such as the American Type Culture Collection (ATCC). It is recommended that non-pathogenic strains be used when learning the various plating methods. By following the procedures described in this protocol, students should be able to: 
 
&#9679; Perform plating procedures without contaminating media. 
&#9679; Isolate single bacterial colonies by the streak-plating method. 
&#9679; Use pour-plating and spread-plating methods to determine the concentration of bacteria. 
&#9679; Perform soft agar overlays when working with phage. 
&#9679; Transfer bacterial cells from one plate to another using the replica-plating procedure. 
&#9679; Given an experimental task, select the appropriate plating method.

When working with media and reagents used to culture microorganisms, aseptic technique must be practiced to ensure contamination is minimized. A variety of plating methods are routinely used to isolate, propagate, or enumerate bacteria and phage, all of which incorporate procedures that maintain the sterility of experimental materials.

Técnicas de laboratorio asépticas: Métodos de Revestimiento

Microorganisms are present on all inanimate surfaces creating ubiquitous sources of possible contamination in the laboratory. Experimental success relies ...

Telomere Length and Telomerase Activity; A Yin and Yang of Cell Senescence

Telomeres are repeating DNA sequences at the tip ends of the chromosomes that are diverse in length and in humans can reach a length of 15,000 base pairs. The telomere serves as a bioprotective mechanism of chromosome attrition at each cell division. At a certain length, telomeres become too short to allow replication, a process that may lead to chromosome instability or cell death. Telomere length is regulated by two opposing mechanisms: attrition and elongation. Attrition occurs as each cell divides. In contrast, elongation is partially modulated by the enzyme telomerase, which adds repeating sequences to the ends of the chromosomes. In this way, telomerase could possibly reverse an aging mechanism and rejuvenates cell viability. These are crucial elements in maintaining cell life and are used to assess cellular aging. In this manuscript we will describe an accurate, short, sophisticated and cheap method to assess telomere length in multiple tissues and species. This method takes advantage of two key elements, the tandem repeat of the telomere sequence and the sensitivity of the qRT-PCR to detect differential copy numbers of tested samples. In addition, we will describe a simple assay to assess telomerase activity as a complementary backbone test for telomere length.

An accurate, short, sophisticated and cheap method is described that assesses telomere length in multiple tissues and species using qRT-PCR. In addition, we will describe a simple assay to assess telomerase activity as a complementary backbone test for telomere length.

La longitud del telómero y la actividad de la telomerasa, una Yin y Yang de la senescencia celular

Telomeres  are repeating DNA sequences at the tip ends of the chromosomes that are diverse  in length and in humans can reach a length of 15,000 base ...

Simple and Effective Administration and Visualization of Microparticles in the Circulatory System of Small Fishes Using Kidney Injection

The systemic administration of micro-size particles into a living organism can be applied for vasculature visualization, drug and vaccine delivery, implantation of transgenic cells and tiny optical sensors. However, intravenous microinjections into small animals, which are mostly used in biological and veterinary laboratories, are very difficult and require trained personnel. Herein, we demonstrate a robust and efficient method for the introduction of microparticles into the circulatory system of adult zebrafish (Danio rerio) by injection into the fish kidney. To visualize the introduced microparticles in the vasculature, we propose a simple intravital imaging technique in fish gills. In vivo monitoring of the zebrafish blood pH was accomplished using an injected microencapsulated fluorescent probe, SNARF-1, to demonstrate one of the possible applications of the described technique. This article provides a detailed description of the encapsulation of pH-sensitive dye and demonstrates the principles of the quick injection and visualization of the obtained microcapsules for in vivo recording of the fluorescent signal. The proposed method of injection is characterized by a low mortality rate (0-20%) and high efficiency (70-90% success), and it is easy to institute using commonly available equipment. All described procedures can be performed on other small fish species, such as guppies and medaka.

This article demonstrates the principles of a quick, minimally invasive injection of fluorescent microparticles into the circulatory system of small fishes and the in vivo visualization of the microparticles in fish blood.

Simple y eficaz administración y visualización de micropartículas en el sistema circulatorio de peces pequeños con inyección de riñón

The systemic administration of micro-size particles into a living organism can be applied for vasculature visualization, drug and vaccine delivery, ...

Nasal Potential Difference to Quantify Trans-epithelial Ion Transport in Mice

The nasal potential difference test has been used for almost three decades to assist in the diagnosis of cystic fibrosis (CF). It has proven to be helpful in cases of attenuated, oligo- or mono-symptomatic forms of CF usually diagnosed later in life, and of CF-related disorders such as congenital bilateral absence of vas deferens, idiopathic chronic pancreatitis, allergic bronchopulmonary aspergillosis, and bronchiectasis. In both clinical and preclinical settings, the test has been used as a biomarker to quantify responses to targeted therapeutic strategies for CF. Adapting the test to a mouse is challenging and can entail an associated mortality. This paper describes the adequate depth of anesthesia required to maintain a nasal catheter in situ for continuous perfusion. It lists measures to avoid broncho-aspiration of solutions perfused in the nose. It also describes the animal care at the end of the test, including administration of a combination of antidotes of the anesthetic drugs, leading to rapidly reversing the anesthesia with full recovery of the animals. Representative data obtained from a CF and a wild-type mouse show that the test discriminates between CF and non-CF. Altogether, the protocol described here allows reliable measurements of the functional status of trans-epithelial chloride and sodium transporters in spontaneously breathing mice, as well as multiple tests in the same animal while reducing test-related mortality.

Here, we present a protocol to measure nasal potential difference in mice. The test quantifies the function of transmembrane ion transporters such as the cystic fibrosis transmembrane conductance regulator and the epithelial sodium channel. It is valuable to evaluate the efficacy of novel therapies for cystic fibrosis.

Diferencia de potencial nasal para cuantificar el transporte de iones Trans epitelial en ratones

The nasal potential difference test has been used for almost three decades to assist in the diagnosis of cystic fibrosis (CF). It has proven to be helpful ...

Bovine Mammary Gland Biopsy Techniques

Bovine mammary gland biopsies allow researchers to collect tissue samples to study cell biology including gene expression, histological analysis, signaling pathways, and protein translation. This article describes two techniques for biopsy of the bovine mammary gland (MG). Three healthy Holstein dairy cows were the subjects. Before biopsies, cows were milked and subsequently restrained in a cattle chute. An analgesic (flunixin meglumine, 1.1 to 2.2 mg/kg of body weight) was administered via jugular intravenous [IV] injection 15-20 min prior to biopsy. For standing sedation, xylazine hydrochloride (0.01-0.05 mg/kg of body weight) was injected via the coccygeal vessels 5-10 min before the procedure. Once adequately sedated, the biopsy site was aseptically prepared and locally anaesthetized with 6 mL of 2% lidocaine hydrochloride via subcutaneous injection. Using aseptic technique, a 2 to 3 cm vertical incision was made using a number 10 scalpel. Core and needle biopsy tools were used. The core biopsy tool was attached to a cordless drill and inserted into the MG tissue through the incision using a clock-wise drill action. The needle biopsy tool was manually inserted into the incision site. Immediately after the procedure, an assistant applied pressure on the incision site for 20 to 25 min using a sterile towel to achieve hemostasis. Stainless steel surgical staples were used to oppose the skin incision. The staples were removed 10 days post-procedure. The main advantages of core and needle biopsies is that both approaches are minimally invasive procedures that can be safely performed in healthy cows. Milk yield following the biopsy was unaffected. These procedures require a short recovery time and result in fewer risks of complications. Specific limitations may include bleeding after the biopsy and infection on the biopsy site. Applications of these techniques include tissue collection for clinical diagnosis and research purposes, such as primary cell culture.

This article presents a bovine mammary gland biopsy using core and needle biopsy tools. Harvested tissue can be used for cell culture or to assess mammary physiology and metabolism including gene expression, protein expression, protein modifications, immunohistochemistry, and metabolite concentrations.

Técnicas de biopsia de glándula mamaria bovina

Bovine mammary gland biopsies allow researchers to collect tissue samples to study cell biology including gene expression, histological analysis, ...

Applications of Spatio-temporal Mapping and Particle Analysis Techniques to Quantify Intracellular Ca2+ Signaling In Situ

Ca2+ imaging of isolated cells or specific types of cells within intact tissues often reveals complex patterns of Ca2+ signaling. This activity requires careful and in-depth analyses and quantification to capture as much information about the underlying events as possible. Spatial, temporal and intensity parameters intrinsic to Ca2+ signals such as frequency, duration, propagation, velocity and amplitude may provide some biological information required for intracellular signalling. High-resolution Ca2+ imaging typically results in the acquisition of large data files that are time consuming to process in terms of translating the imaging information into quantifiable data, and this process can be susceptible to human error and bias. Analysis of Ca2+ signals from cells in situ typically relies on simple intensity measurements from arbitrarily selected regions of interest (ROI) within a field of view (FOV). This approach ignores much of the important signaling information contained in the FOV. Thus, in order to maximize recovery of information from such high-resolution recordings obtained with Ca2+dyes or optogenetic Ca2+ imaging, appropriate spatial and temporal analysis of the Ca2+ signals is required. The protocols outlined in this paper will describe how a high volume of data can be obtained from Ca2+ imaging recordings to facilitate more complete analysis and quantification of Ca2+ signals recorded from cells using a combination of spatiotemporal map (STM)-based analysis and particle-based analysis. The protocols also describe how different patterns of Ca2+ signaling observed in different cell populations in situ can be analyzed appropriately. For illustration, the method will examine Ca2+ signaling in a specialized population of cells in the small intestine, interstitial cells of Cajal (ICC), using GECIs.

Applications of Spatio-temporal Mapping and Particle Analysis Techniques to Quantify Intracellular Ca2+ Signaling In Situ

Genetically encoded Ca2+ indicators (GECIs) have radically changed how in situ Ca2+ imaging is performed. To maximize data recovery from such recordings, appropriate analysis of Ca2+ signals is required. The protocols in this paper facilitate the quantification of Ca2+ signals recorded in situ using spatiotemporal mapping and particle-based analysis.

Aplicaciones de la cartografía espacio-temporal y técnicas de análisis de partículas para cuantificar Ca intracelular2 + señalización In Situ

Ca2+ imaging of isolated cells or specific types of cells within intact tissues often reveals complex patterns of Ca2+ signaling. This activity requires ...

Immunohistochemistry Techniques to Analyze Cellular Proliferation and Neurogenesis in Rats Using the Thymidine Analog BrdU

One of the most important things in the field of adult hippocampal neurogenesis (AHN) is the identification of the newly generated cells. The immunodetection of thymidine analogs (such as 5-Bromo-2&#39;-deoxyuridine (BrdU)) is a standard technique used for visualizing these newly generated cells. Therefore, BrdU is usually injected in small animals intraperitoneally, so the thymidine analog gets incorporated into dividing cells during DNA synthesis. Detection is performed by immunohistochemical analysis of brain slices. Every research group that has been using this technique can appreciate that it requires special attention to minute details to achieve a successful stain. For instance, an important step is DNA denaturation with HCl, which allows it to reach the cell nucleus to stain it. However, the existing scientific reports describe very few of such steps in detail. Therefore, standardizing the technique is challenging for new laboratories as it can take several months to yield positive and successful outcomes. The purpose of this work is to describe and elaborate the steps to obtain positive and successful outcomes of the immunostaining technique in detail when working with the thymidine analog BrdU. The protocol includes the reagent preparation and setup, administration of thymidine analog in a rodent, transcardial perfusion, tissue preparation, peroxidase immunohistochemical reaction, use of avidin-biotin complex, immunofluorescence, counterstaining, microscopy imaging, and cell analysis.

This paper presents four of the most common techniques for visualizing BrdU positive cells to measure adult neurogenesis in rats. This work includes instructions for reagent preparation, thymidine analog administration, transcardial perfusion, tissue preparation, peroxidase immunohistochemical reaction, immunofluorescence, signal amplification, counterstaining, microscopy imaging, and cell analysis.

Técnicas para inducir la senescencia celular y cuantificar

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