Este protocolo ha sido probado y optimizado en el laboratorio del Dr. David Scadden. El financiamiento es provisto por el Dana Farber Cancer Institute / Hospital General de Massachusetts Clínica de Hematología y Oncología del Programa de Becas.

<ol><li> Al comenzar el experimento mediante la extracción de células mensajeras para ser utilizado en el experimento. Para este experimento actual que estamos interesados ​​en saber si la recalada de toda la médula ósea de los nichos en los huesos largos de los animales receptores es diferente para las células de la médula ósea extraídas de animales WT como C57BL/6J (WT) y los que son transgénicos KO para el receptor de lisofosfatídico 1 (LPAR1) (KO). </li><li> Antes de empezar el experimento, vamos a recoger los materiales que necesitamos para este experimento. En nuestro laboratorio de todas las disecciones del ratón se llevan a cabo en una campana de flujo laminar de cultivo de tejidos, especialmente si las células se van a trasplantar a un animal receptor en lugar de ser utilizados para el análisis ex-vivo. Empezamos poniendo una hoja de color azul dentro de la campana. Otros objetos necesarios incluyen un par de pinzas y un par de tijeras afiladas que se han autoclave, una solución estéril de bisturí desechable hisopos y alcohol. Tendremos que modificar PBS estéril y un 6 y placa, un mortero, maja azul, 50cc tubo cónico cubierto y un filtro desechable 70uM. </li><li> Comenzamos con un TE y un ratón KO. </li><li> Estos ratones son sacrificados por inhalación de CO 2 y se sumergen en un 70% isopropranolol durante 5 segundos. Este paso evita la contaminación de las células de interés con la piel del ratón y en nuestras manos, no ha dado lugar a ningún tipo de compromiso en el rendimiento de las células o los resultados experimentales. </li><li> Los ratones se diseca a su vez con un par de pinzas y tijeras afiladas. Por lo general, comienzan con el ratón WT como una cuestión de rutina. Un recorte pequeña en la piel ventral del ratón que recubre el abdomen y la piel se estira con las manos. La piel se desprende con facilidad las extremidades posteriores. El fémur y la tibia se extraen con cuidado de no desplazar la cabeza del fémur, ya que contiene una gran cantidad de médula ósea. Las extremidades superiores se desprenden de torso del animal mediante la simple aplicación de tracción para, manteniendo el torso inmóvil. Esto elimina las extremidades superiores como una sola pieza. El húmero se extraen de los miembros superiores. </li><li> Los huesos extraídas se colocan en PBS modificado que se ha añadido a 6 placas. Modificado PBS se hace mediante la adición de 2 ml de inactivado por calor suero fetal bovino y 2 ml de EDTA 0,5 M pH 8. Esta solución se filtra a través de un filtro Nalgene de 0,45 m y se puede almacenar a 4 grados Celsius durante al menos un mes. </li><li> Es esencial para etiquetar los pozos de la placa con el fin de ser capaces de identificar los huesos WT y KO correctamente. </li><li> Los cadáveres del ratón son retirados y eliminados fuera. </li><li> Una nueva hoja se coloca en el capó y los huesos se limpian con un bisturí desechable. </li><li> Los huesos limpios se coloca un ratón en un momento en el mortero. Dos ml de PBS modificado se añade al mortero y los huesos se trituran con un mortero. Es importante que el primer fragmento de los huesos con 10 movimientos de un lado a otro de la mano del mortero y luego pulverizarlos con movimientos circulares rotatorios. Yo suelo hacer 50 las agujas del reloj, de 50 movimientos en sentido contrario y así sucesivamente hasta que el material que queda en el mortero es de color blanco y el SBP modificado, añadido al material permanece de color blanco o transparente. </li><li> Después de cada juego de 50 movimientos circulares de trituración, que transfiera el líquido de la argamasa de un filtro de 70 uM colocado en la parte superior de un tubo cónico de 50 ml. No te olvides de añadir 2 ml de PBS para el mortero después de cada transferencia al filtro. Usted no quiere tratar de pulverizar los huesos secos o dejarlas secar durante un período de tiempo ya que esto dará lugar a la apoptosis de las células. </li><li> Una vez que el material en el mortero se convierte en blanco, el material en el filtro se transfiere a los morteros y la trituración se realiza de nuevo. Esto asegura que las células en el filtro no se desperdicien. Normalmente se tarda uno o dos juegos de circular movimientos rotatorios para hacer de nuevo el material en el blanco de mortero en color y en ese momento de la extracción de las células es completa. </li><li> La solución en el tubo cónico está centrifugada (por favor, recuerde que debe mantener las células de los ratones WT y KO por separado. Por lo tanto, tendrá dos tubos diferentes (uno con las células WT y la otra con células KO). Centrifugar a 1200 rpm durante 10 minutos. </li><li> Aspirar el sobrenadante utilizando pipetas separadas para cada tubo aspirador. Añadir 2 ml de solución amortiguadora de lisis ACK para cada pastilla. Esta solución amortiguadora de lisis debe ser estéril. Incubar en hielo durante 5 minutos. </li><li> Añadir 8 cc de modificar PBS a cada tubo. Tomar 10 ul de cada tubo y la pipeta en dos pozos separados en una placa y 96. Colocar los tubos en la centrífuga y el giro que a 1200 rpm durante 10 minutos. </li><li> Mientras que los tubos están girando, añadir 30 ul de tryphan colorante azul y 60 ul de PBS modificado en cada pocillo de la placa de 96 y que lleva a las células de interés. </li><li> Añadir 10 ul de la mezcla (por favor, mezclar bien con la pipeta hacia arriba y abajo) en un hemocitómetro y contar las células en las cuatro plazas exteriores. </li><li> El recuento de células en cada muestra por ml es el número de células así contado, dividido por 4 y multiplied por 100 000. </li><li> Una vez que la centrifugación, retire los tubos de la centrífuga y resuspender las células en PBS sin calcio, magnesio o la glutamina L a una concentración de 20 millones de células por ml. Es probable que tenga unos 5 ml de volumen para el WT y 5 ml de volumen para que el animal KO. A partir de este paso vamos a utilizar PBS, sin modificar el protocolo para la PBS. </li><li> A cada tubo agregar DII, un colorante de tinción de células, para lograr una concentración final de 5 um. Vortex inmediatamente por 10 segundos. Se incuba a 37 grados durante 10 minutos y evitar la exposición a la luz. </li><li> Llenar los tubos con PBS y girar durante 10 minutos a 1200 rpm. </li><li> Después de la centrifugación, se aspira el sobrenadante y resuspender las células en PBS a 40 millones de células por ml. </li><li> Carga de 500 ul en jeringas de 1 cc con una aguja 27G (5 jeringas para el ratón WT y 5 jeringas para los ratones KO). Puede ser prudente para preparar 6 jeringas para cada cohorte. Tener uno extra puede ayudar a que las inyecciones de vena de la cola que vamos a hacer a continuación puede ser complicado. </li><li> Cubrir las jeringas con papel de aluminio con el fin de mantener el DII de la desintegración. </li><li> Inyectar 500 ul de la mezcla de células en cada animal receptor, (5 para cada cohorte). </li><li> Estos animales deben ser irradiados con 9 Gy de irradiación de 4-24 horas antes de la inyección. </li><li> 48 horas después de la inyección, la médula ósea de la cosecha de las extremidades posteriores de cada animal receptor. </li><li> Proceso como se describe anteriormente para los donantes. Resuspender las células de cada animal en 1 cc de PBS. Obtener un recuento de células con un hemocitómetro. </li><li> Leer en el citómetro de flujo LSR II de BD o un instrumento equivalente. El resultado puede ser expresado como el porcentaje o el número absoluto de células en la médula ósea que son analizados DII positivo. </li></ol>

<ol>
	<li>Adams, G. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+cell+engraftment+at+the+endosteal+niche+is+specified+by+the+calcium-sensing+receptor.">Stem cell engraftment at the endosteal niche is specified by the calcium-sensing receptor.</a> Nature. 439 (7076), 599-603 (2006).</li><li>Broxmeyer, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemokines+in+hematopoiesis.">Chemokines in hematopoiesis.</a> Curr Opin Hematol. 15 (1), 49-58 (2008).</li></ol>

Homing es el proceso mediante el cual las células de la médula ósea como células madre, células progenitoras y las células diferenciadas, su camino en la médula ósea después de ser inyectadas en el torrente sanguíneo o en la cavidad de la médula ósea de ratones. Como se desprende de la definición, un científico puede optar por estudiar el homing de las células madre hematopoyéticas, las células progenitoras o células diferenciadas identificadas por inmunofenotipo y aislado por la clasificación de cél...

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<td>DPBS (Dulbecco&#x2019;s Phosphate Buffered Saline</td>
<td>&nbsp;</td>
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homing of hematopoietic cells to the bone marrow

Homing es el fenómeno por el cual las células hematopoyéticas trasplantadas son capaces de viajar y se injertan o establecer su residencia en la médula ósea. Chemomkines diversos y receptores están implicados en el homing de las células madre hematopoyéticas. [1, 2] Este documento describe el protocolo clásico homing utilizadas en estudios de células madre hematopoyéticas. En general, esto consiste en aislar la población de células cuyas necesidades homing para ser investigados, la tinción de esta población con un tinte de interés e inyectar estas células en el torrente sanguíneo de un animal receptor. El animal receptor entonces se sacrificó en un tiempo predeterminado después de la inyección y la médula ósea para evaluar el porcentaje o el número absoluto de células que son positivas para el tinte de interés. En uno de los proyectos experimentales más comunes, la eficiencia de homing de las células hematopoyéticas de dos animales genéticamente distintas (un animal de tipo salvaje y el knock-out correspondiente) es comparada. En este artículo se describe el protocolo de células hematopoyéticas de recalada en el marco de como experimento.

Watch this Scientific Journal Video about Homing of Hematopoietic Cells to the Bone Marrow at JoVE.com

Homing of Hematopoietic Cells to the Bone Marrow

En este artículo se describe un protocolo que se utiliza para estudiar el homing de las células hematopoyéticas de sus nichos en la médula ósea.

Mensajeras de las células hematopoyéticas de la médula ósea

Homing is the phenomenon whereby transplanted hematopoietic cells are able to travel to and engraft or establish residence in the bone marrow.  Various ...

homing-of-hematopoietic-cells-to-the-bone-marrow

Research

JoVE Journal

Biology

29.4K vistas.  MGH - Massachusetts General Hospital. En este artículo se describe un protocolo que se utiliza para estudiar el homing de las células hematopoyéticas de sus nichos en la médula ósea.

Video: Homing of Hematopoietic Cells to the Bone Marrow

Isolation and Analysis of Hematopoietic Stem Cells from the Placenta

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. All HSCs emerge during embryonic development, after which their pool size is maintained by self-renewing cell divisions. Identifying the anatomical origin of HSCs and the critical developmental events regulating the process of HSC development has been complicated as many anatomical sites participate during fetal hematopoiesis. Recently, we identified the placenta as a major hematopoietic organ where HSCs are generated and expanded in unique microenvironmental niches (Gekas, et al 2005, Rhodes, et al 2008). Consequently, the placenta is an important source of HSCs during their emergence and initial expansion.
In this article, we show dissection techniques for the isolation of murine placenta from E10.5 and E12.5 embryos, corresponding to the developmental stages of initiation of HSCs and the peak in the size of the HSC pool in the placenta, respectively. In addition, we present an optimized protocol for enzymatic and mechanical dissociation of placental tissue into single-cell suspension for use in flow cytometry or functional assays. We have found that use of collagenase for single-cell suspension of placenta gives sufficient yields of HSCs. An important factor affecting HSC yield from the placenta is the degree of mechanical dissociation prior to, and duration of, enzymatic treatment.
We also provide a protocol for the preparation of fixed-frozen placental tissue sections for the visualization of developing HSCs by immunohistochemistry in their precise cellular niches. As hematopoietic specific antigens are not preserved during preparation of paraffin embedded sections, we routinely use fixed frozen sections for localizing placental HSCs and progenitors.

We have identified the placenta as a major hematopoietic organ during development. We found that hematopoietic stem cells (HSCs) are both generated and expanded in the placenta in unique microenvironmental niches. Here, we describe experimental techniques required for isolation and visualization of HSCs in the mouse placenta.

Aislamiento y análisis de las células madre hematopoyéticas de la placenta

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. ...

Investigación

Biología

Culture of myeloid dendritic cells from bone marrow precursors

Myeloid dendritic cells (DCs) are frequently used to study the interactions between innate and adaptive immune mechanisms and the early response to infection. Because these are the most potent antigen presenting cells, DCs are being increasingly used as a vaccine vector to study the induction of antigen-specific immune responses. In this video, we demonstrate the procedure for harvesting tibias and femurs from a donor mouse, processing the bone marrow and differentiating DCs in vitro. The properties of DCs change following stimulation: immature dendritic cells are potent phagocytes, whereas mature DCs are capable of antigen presentation and interaction with CD4+ and CD8+ T cells. This change in functional activity corresponds with the upregulation of cell surface markers and cytokine production. Many agents can be used to mature DCs, including cytokines and toll-like receptor ligands. In this video, we demonstrate flow cytometric comparisons of expression of two co-stimulatory molecules, CD86 and CD40, and the cytokine, IL-12, following overnight stimulation with CpG or mock treatment. After differentiation, DCs can be further manipulated for use as a vaccine vector or to generate antigen-specific immune responses by in vitro pulsing using peptides or proteins, or transduced using recombinant viral vectors. 

This video demonstrates the procedure for differentiating myeloid dendritic cells from mouse bone marrow. Isolation of mouse tibia and femur, and processing of bone marrow are demonstrated. Pictures demonstrating cell morphology before and after differentiation, and figures depicting cell phenotype and IL-12 production following maturation using CpG are shown.

Cultura de células dendríticas mieloides a partir de precursores de médula ósea

Myeloid dendritic cells (DCs) are frequently used to study the interactions between innate and adaptive immune mechanisms and the early response to ...

Generation of Bone Marrow Derived Murine Dendritic Cells for Use in 2-photon Imaging

Several methods for the preparation of murine dendritic cells can be found in the literature. Here, we present a method that produces greater than 85% CD11c high dendritic cells in culture that home to the draining lymph node after subcutaneous injection and present antigen to antigen specific T cells (see video). Additionally, we use Essen Instruments Incucyte to track dendritic cell maturation, where, at day 10, the morphology of the cultured cells is typical of a mature dendritic cell and &lt;85% of cells are CD11chigh. The study of antigen presentation in peripheral lymph nodes by 2-photon imaging revealed that there are three distinct phases of dendritic cell and T cell interaction1, 2. Phase I consists of brief serial contacts between highly motile antigen specific T cells and antigen carrying dendritic cells1, 2. Phase two is marked by prolonged contacts between antigen-specific T cell and antigen bearing dendritic cells1, 2. Finally, phase III is characterized by T cells detaching from dendritic cells, regaining motility and beginning to divide1, 2. This is one example of the type of antigen-specific interactions that can be analyzed by two-photon imaging of antigen-loaded cell tracker dye-labeled dendritic cells.

Antigen presentation in secondary lymphoid organs by dendritic cells is crucial for the initiation of the T cell mediated adaptive immune response. Here we demonstrate the culture of bone marrow derived murine dendritic cells, activation, and labeling for 2-photon imaging.

Generación de médula ósea procedentes de células murinas dendríticas para su uso en dos fotones de imágenes

Several methods for the preparation of murine dendritic cells can be found in the literature. Here, we present a method that produces greater than 85% ...

The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell  electroporation system and Gene Pulser  electroporation buffer were specifically developed to transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells.This video demonstrates how to establish primary hematopoietic cell cultures from murine bone marrow, and then prepare them for electroporation in the MXcell system. We begin by isolating femur and tibia. Bone marrow from both femur and tibia are then harvested and cultures are established. Cultured bone marrow cells are then transfected and analyzed.

This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation system.

La preparación de cultivos primarios de células hematopoyéticas de la médula ósea murina por electroporación

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...

Lentiviral-mediated Knockdown During Ex Vivo Erythropoiesis of Human Hematopoietic Stem Cells

Erythropoiesis is a commonly used model system to study cell differentiation. During erythropoiesis, pluripotent adult human hematopoietic stem cells (HSCs) differentiate into oligopotent progenitors, committed precursors and mature red blood cells 1. This process is regulated for a large part at the level of gene expression, whereby specific transcription factors activate lineage-specific genes while concomitantly repressing genes that are specific to other cell types 2. Studies on transcription factors regulating erythropoiesis are often performed using human and murine cell lines that represent, to some extent, erythroid cells at given stages of differentiation 3-5. However transformed cell lines can only partially mimic erythroid cells and most importantly they do not allow one to comprehensibly study the dynamic changes that occur as cells progress through many stages towards their final erythroid fate. Therefore, a current challenge remains the development of a protocol to obtain relatively homogenous populations of primary HSCs and erythroid cells at various stages of differentiation in quantities that are sufficient to perform genomics and proteomics experiments.
Here we describe an ex vivo cell culture protocol to induce erythroid differentiation from human hematopoietic stem/progenitor cells that have been isolated from either cord blood, bone marrow, or adult peripheral blood mobilized with G-CSF (leukapheresis). This culture system, initially developed by the Douay laboratory 6, uses cytokines and co-culture on mesenchymal cells to mimic the bone marrow microenvironment. Using this ex vivo differentiation protocol, we observe a strong amplification of erythroid progenitors, an induction of differentiation exclusively towards the erythroid lineage and a complete maturation to the stage of enucleated red blood cells. Thus, this system provides an opportunity to study the molecular mechanism of transcriptional regulation as hematopoietic stem cells progress along the erythroid lineage. 
Studying erythropoiesis at the transcriptional level also requires the ability to over-express or knockdown specific factors in primary erythroid cells. For this purpose, we use a lentivirus-mediated gene delivery system that allows for the efficient infection of both dividing and non-dividing cells 7. Here we show that we are able to efficiently knockdown the transcription factor TAL1 in primary human erythroid cells. In addition, GFP expression demonstrates an efficiency of lentiviral infection close to 90%. Thus, our protocol provides a highly useful system for characterization of the regulatory network of transcription factors that control erythropoiesis.

Lentiviral-mediated Knockdown During Ex Vivo Erythropoiesis of Human Hematopoietic Stem Cells

An ex vivo protocol to generate mature human red blood cells from hematopoietic stem/progenitors is described. Additionally we describe an efficient lentiviral-delivery method to knockdown the transcription factor TAL1 in primary erythroid cells. The efficiency of lentivirus mediated gene delivery is demonstrated using GFP expressing viruses.

Lentiviral mediada por derribo Durante Ex Vivo Eritropoyesis de las células estaminales hematopoyéticas

Erythropoiesis is a commonly used model system to study cell differentiation. During erythropoiesis, pluripotent adult human hematopoietic stem cells ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) maintain the turnover of all mature blood cell lineages. The coordination of the complex signals leading to specific HSC fates relies upon the interaction between HSCs and the intricate bone marrow microenvironment, which is still poorly understood[1-2].
We describe how by combining a newly developed specimen holder for stable animal positioning with multi-step confocal and two-photon in vivo imaging techniques, it is possible to obtain high-resolution 3D stacks containing HSPCs and their surrounding niches and to monitor them over time through multi-point time-lapse imaging. High definition imaging allows detecting ex vivo labeled hematopoietic stem and progenitor cells (HSPCs) residing within the bone marrow. Moreover, multi-point time-lapse 3D imaging, obtained with faster acquisition settings, provides accurate information about HSPC movement and the reciprocal interactions between HSPCs and stroma cells.
Tracking of HSPCs in relation to GFP positive osteoblastic cells is shown as an exemplary application of this method. This technique can be utilized to track any appropriately labeled hematopoietic or stromal cell of interest within the mouse calvarium bone marrow space.

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and movement.

En Vivo Tracking 4-Dimensional de madre hematopoyéticas y células progenitoras en ratones adultos de calota de Médula Ósea

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Osteoclast Derivation from Mouse Bone Marrow

Osteoclasts are highly specialized cells that are derived from the monocyte/macrophage lineage of the bone marrow. Their unique ability to resorb both the organic and inorganic matrices of bone means that they play a key role in regulating skeletal remodeling. Together, osteoblasts and osteoclasts are responsible for the dynamic coupling process that involves both bone resorption and bone formation acting together to maintain the normal skeleton during health and disease.
As the principal bone-resorbing cell in the body, changes in osteoclast differentiation or function can result in profound effects in the body. Diseases associated with altered osteoclast function can range in severity from lethal neonatal disease due to failure to form a marrow space for hematopoiesis, to more commonly observed pathologies such as osteoporosis, in which excessive osteoclastic bone resorption predisposes to fracture formation.
An ability to isolate osteoclasts in high numbers in vitro has allowed for significant advances in the understanding of the bone remodeling cycle and has paved the way for the discovery of novel therapeutic strategies that combat these diseases. 
Here, we describe a protocol to isolate and cultivate osteoclasts from mouse bone marrow that will yield large numbers of osteoclasts.

Osteoclasts are the principal bone-resorbing cell in the body. An ability to isolate osteoclasts in large numbers has resulted in significant advances in the understanding of osteoclast biology. In this protocol, we describe a method for isolation, cultivating and quantifying osteoclast activity in vitro.

Osteoclastos Derivación de médula ósea de ratón

Osteoclasts are highly specialized cells that are derived from the monocyte/macrophage lineage of the bone marrow. Their unique ability to resorb both the ...

Expression of Fluorescent Fusion Proteins in Murine Bone Marrow-derived Dendritic Cells and Macrophages

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation of an adaptive immune response. Experimental work with these cells is rather challenging. Their abundance in organs and tissues is relatively low. As a result, they cannot be isolated in large numbers. They are also difficult to transfect with cDNA constructs. In the murine model, these problems can be partially overcome by in vitro differentiation from bone marrow progenitors in the presence of M-CSF for macrophages or GM-CSF for dendritic cells. In this way, it is possible to obtain large amounts of these cells from very few animals. Moreover, bone marrow progenitors can be transduced with retroviral vectors carrying cDNA constructs during early stages of cultivation prior to their differentiation into bone marrow derived dendritic cells and macrophages. Thus, retroviral transduction followed by differentiation in vitro can be used to express various cDNA constructs in these cells. The ability to express ectopic proteins substantially extends the range of experiments that can be performed on these cells, including live cell imaging of fluorescent proteins, tandem purifications for interactome analyses, structure-function analyses, monitoring of cellular functions with biosensors and many others. In this article, we describe a detailed protocol for retroviral transduction of murine bone marrow derived dendritic cells and macrophages with vectors coding for fluorescently-tagged proteins. On the example of two adaptor proteins, OPAL1 and PSTPIP2, we demonstrate its practical application in flow cytometry and microscopy. We also discuss the advantages and limitations of this approach.

In this article, we provide a detailed protocol for the expression of fluorescent fusion proteins in murine bone marrow derived dendritic cells and macrophages. The method is based on the transduction of bone marrow progenitors with retroviral constructs followed by differentiation into macrophages and dendritic cells in vitro.

Expresión de proteínas fluorescentes de fusión en murinas médula ósea células dendríticas y macrófagos

Dendritic cells and macrophages are crucial cells that form the first line of defense against pathogens. They also play important roles in the initiation ...

Isolation, Purification, and Differentiation of Osteoclast Precursors from Rat Bone Marrow

Osteoclasts are large, multinucleated, and bone-resorbing cells of the monocyte-macrophage lineage that are formed by the fusion of monocytes or macrophage precursors. Excessive bone resorption is one the most significant cellular mechanisms leading to osteolytic diseases, including osteoporosis, periodontitis, and periprosthetic osteolysis. The main physiological function of osteoclasts is to absorb both the hydroxyapatite mineral component and the organic matrix of bone, generating the characteristic resorption appearance on the surface of bones. There are relatively few osteoclasts compared to other cells in the body, especially in adult bones. Recent studies have focused on how to obtain more mature osteoclasts in less time, which has always been a problem. Several improvements in the isolation and culture techniques have developed in laboratories in order to obtain more mature osteoclasts. Here, we introduce a method that isolates bone marrow in less time and with less effort compared to the traditional procedure, using a special and simple device. With the use of density gradient centrifugation, we obtain large amounts of fully differentiated osteoclasts from rat bone marrow, which are identified by classical methods.

Osteoclasts are tissue-specific macrophage polykaryons derived from the monocyte-macrophage lineage of hematopoietic stem cells. This protocol describes how to isolate bone marrow cells so that large quantities of osteoclasts are obtained while reducing the risk of accidents found in traditional methods.

Aislamiento, purificación y diferenciación de los precursores de osteoclastos de la médula ósea de rata

Osteoclasts are large, multinucleated, and bone-resorbing cells of the monocyte-macrophage lineage that are formed by the fusion of monocytes or ...

Proplatelet Formation Dynamics of Mouse Fresh Bone Marrow Explants

The last stage of megakaryopoiesis leads to cytoplasmic extensions from mature megakaryocytes, the so-called proplatelets. Much has been learned about the proplatelet formation using in vitro-differentiated megakaryocytes; however, there is an increasing evidence that conventional culture systems do not faithfully recapitulate the differentiation/maturation process that takes places inside the bone marrow. In this manuscript, we present an explant method initially described in 1956 by Thi&#233;ry and Bessis to visualize megakaryocytes which have matured in their native environment, thus circumventing potential artifacts and misinterpretations. Fresh bone marrows are collected by flushing the femurs of mice, sliced into 0.5 mm cross sections, and placed in an incubation chamber at 37 &#176;C containing a physiological buffer. Megakaryocytes become gradually visible at the explant periphery and are observed up to 6 hours under an inverted microscope coupled to a video camera. Over time, megakaryocytes change their shape, with some cells having a spherical form and others developing thick extensions or extending many thin proplatelets with extensive branching. Both qualitative and quantitative investigations are carried out. This method has the advantage of being simple, reproducible, and fast as numerous megakaryocytes are present, and classically half of them form proplatelets in 6 hours compared to 4 days for cultured mouse megakaryocytes. In addition to the study of mutant mice, an interesting application of this method is the straightforward evaluation of the pharmacological agents on the proplatelet extension process, without interfering with the differentiation process that may occur in cultures.

Here, we detail the bone marrow explant method, from sample preparation to microscopic slide analysis, to evaluate the ability of megakaryocytes which have differentiated in their physiological environment to form proplatelets.

Dinámica de formación de proplatlets de explantes de médula ósea fresca de ratón

The last stage of megakaryopoiesis leads to cytoplasmic extensions from mature megakaryocytes, the so-called proplatelets. Much has been learned about the ...