This work was supported by the Ronald Peter Griggs Memorial Fellowship in ALS Research (to KP) and a Neuromuscular Research Partnership Program grant from the CIHR, the ALS Society of Canada, and Muscular Dystrophy Canada (JNM-69682) to CK and FMR. Additional support was also provided by the ALS Society of America (57969). We would like to thank Dr. R. Keith Humphries from the Terry Fox Laboratory/Department of Pathology, BC Cancer Agency, Vancouver, Canada and the staff at the Simon Fraser University Animal Care Unit.

NOTA: Ética Declaración: Este protocolo ha sido revisado y aprobado por el Comité de Cuidado de Animales de la Universidad Simon Fraser (UACC; permitir números 1037K-12 y 1060K-03) y está en conformidad con el Consejo Canadiense de los Animales, la Guía del NIH para la la Directiva CEE Cuidado y Uso de Animales de Laboratorio, y. 1. Consideraciones especiales NOTA: El busulfán es citotóxica. Manipule y deseche de acuerdo a la hoja de datos de seguridad de materiales y directrices institucionales. <ol><li> Realice todas las técnicas asépticamente en una campana de flujo laminar. </li><li> Esterilizar los instrumentos antes de su uso envolviendo en un material de envasado apropiado, tal como un paquete de la cáscara, y tratamiento en autoclave. </li><li> Mientras que el riesgo de infección es menor con busulfán acondicionado en comparación con la irradiación, manejar animales sólo en una campana de flujo laminar para las primeras 2 semanas después del trasplante. </li></ol> 2. Acondicionamiento deLos ratones receptores <ol><li> Diluir busulfán a 3 mg / ml con solución salina estéril tamponada con fosfato (PBS). NOTA: Es importante hacer una dilución fresca de busulfán justo antes de su uso cada día de la inyección. </li><li> Administrar 20 mg / kg de busulfan diluida a ratones receptores mediante inyección IP diaria. </li><li> Repetir las inyecciones IP diarias de 20 mg / kg busulfán hasta una dosis total de 60-100 mg / kg ha sido entregado (es decir, para un / kg dosis total de 80 mg, administrar 20 mg / kg de busulfan durante 4 días consecutivos). </li></ol> 3. Aislamiento de células de médula ósea de donantes NOTA: Este protocolo ha sido utilizado con éxito para aislar y preparar células BM de hasta 5 ratones donantes. Típicamente, el rendimiento de células por ratón es de aproximadamente 30-40 million BMDCs, lo cual es suficiente para trasplantar 12-16 ratones receptores. Si se necesitan más ratones donantes puede ser necesario ajustar en consecuencia el protocolo. <ol><li> Tras el último día de busulfán acondicionado euthanize un ratón donante GFP (uno a seis meses de edad) con CO 2 (o por otro procedimiento de eutanasia aceptado en la institución). Para evitar complicaciones injerto utilizan donantes singénicos que son del mismo sexo que los destinatarios. </li><li> Pulverizar ratón con etanol al 70%. La piel de elevación con las tijeras quirúrgicas abdomen y utilizando hacer una incisión a través de la piel de la cavidad abdominal arriba de la pierna hacia el tobillo. Sosteniendo el pie, tire firmemente la piel desde el tobillo hacia la cadera exponiendo el tejido de la pierna. </li><li> Recorte el tejido muscular y grasa del fémur para exponer la articulación de la cadera. </li><li> Mientras tira suavemente con el pie para extender la pierna, pulse la tijera contra la articulación de la cadera. Cortar justo por encima de la cabeza del fémur con cuidado de no cortar el propio fémur. </li><li> Para ayudar a mantener la esterilidad, mantenga la pierna con el pie y limpiar cualquier resto de tejido de los huesos por el roce de la superficie del hueso con tejidos tratados en autoclave. </li><li> Separar el fémur y la tibia mediante el corte a través de la articulación de la rodilla ycolocar el fémur en una placa de cultivo que contiene PBS estéril. Incubar en hielo. </li><li> Retire y deseche el peroné por el corte en los puntos donde el peroné se conecta a la tibia. Coloque la tibia en la placa de cultivo con el fémur y se incuba en hielo. </li><li> Repita los pasos 3.2 a 3.7 de la otra pierna, y si es necesario, ratones donantes adicionales. Después de la eliminación de los huesos, esterilizar los instrumentos quirúrgicos con un esterilizador de cuentas caliente o utilizar un nuevo conjunto de herramientas estériles para las etapas ulteriores. </li><li> Para los fémures, mantenga el fémur con pinzas y con unas tijeras quirúrgicas cuidadosamente &#39;afeitado&#39; los extremos distales de los huesos. Retire tan poco del hueso como sea necesario para exponer la cavidad BM. </li><li> Llene una jeringa con 3 ml de PBS estéril y adjuntar una aguja de calibre 23. Taladro con cuidado la aguja en la cavidad BM y lave el BM en una placa de cultivo estéril. Asegúrese de raspar la cavidad medular con la punta de la aguja para asegurar la eliminación de todas las células deseadas. Después de la extracción,asegúrese de que el BM rojo ya no es visible y el hueso aparece ahora blanco. </li><li> Repita los pasos 3.9 a 3.10 para fémures posteriores, puesta en común de todo el BM en la misma placa de cultivo. </li><li> Para las tibias, mantenga la tibia con unas pinzas y con cuidado &#39;afeitado&#39; el final, donde la tibia se adjuntó a la rodilla para exponer la cavidad BM. Haga un segundo corte a lo largo del hueso donde termina el BM roja visible. </li><li> Llene una jeringa con 3 ml de PBS estéril y adjuntar una aguja de calibre 25. Suavemente inserte la aguja en la cavidad BM (desde el extremo que se adjuntó a la rodilla) y enjuagar el BM en la placa de cultivo que contiene el BM de los fémures. Raspe las paredes de la cavidad BM con la aguja para eliminar todas las células. Después de la extracción, asegúrese de que el BM rojo ya no es visible y el hueso aparece ahora blanco. </li><li> Repita los pasos 3.12 a 3.13 para la posterior tibias, puesta en común de todo el BM en la misma placa de cultivo. </li><li> Tritura suavemente el BM con una punta de pipeta de 1 ml para disociar el cells. </li><li> Pasar la suspensión celular a través de un filtro de cesta 40 mM en un tubo de centrífuga de 50 ml estéril. Enjuague el plato con PBS para obtener las células restantes y transferir este a través del filtro en el tubo de centrífuga. </li><li> Centrifugar durante 5 min a 450 xg a 4 ° C. Retirar y desechar el sobrenadante. </li><li> Vuelva a suspender el sedimento en 3 ml de tampón de lisis de los eritrocitos. Incubar en hielo durante 8,5 min. </li><li> Añadir ~ 30 ml de PBS estéril para saciar el buffer de lisis. </li><li> Centrifugar durante 5 min a 450 xg a 4 ° C. Retirar y desechar el sobrenadante. </li><li> Vuelva a suspender el sedimento en 1 ml de PBS estéril. Mantener en hielo. </li><li> Tomar una pequeña alícuota del homogeneizado celular y se diluye con PBS (1: 100 para ratón 1; 1: 200 para 2 ratones, etc.) para cuantificar el número de células usando un hemocitómetro. </li><li> Diluir la suspensión de células a 8 x 10 6 células / ml y se incuba en hielo hasta la inyección. </li></ol> 4. Trasplante de Médula Ósea <ol><li> Fill una jeringa de 0,5 ml (con una aguja de insulina 28 G) con 300 l de suspensión celular diluida para cada ratón a inyectar. Asegúrese de eliminar las burbujas de aire presentes en la jeringa. </li><li> Coloque la jaula del ratón contiene los ratones receptores acondicionado en una almohadilla eléctrica y permitir que las venas de la cola se dilaten. </li><li> Tome un ratón receptor y colocar en el dispositivo de retención. Limpiar la cola con una gasa quirúrgica empapada con etanol al 70%. </li><li> Sostenga firmemente la cola y con el bisel hacia arriba, inserte suavemente la aguja en una de las venas de la cola laterales e inyectar la suspensión celular. </li><li> Mantenga gasa quirúrgica en el sitio de la inyección hasta que el sangrado se detiene antes de introducir el ratón en una nueva jaula limpia. </li></ol> 5. Estimación de la Extensión de la BM quimerismo NOTA: Los niveles de quimerismo suelen ser variable en la sangre periférica en 1 semana post-trasplante de médula ósea, y como tal, los niveles de quimerismo normalmente se estiman al menos 2 semanas post-TMO. Los niveles de chimerism debe alcanzar&gt; 80% GFP + células en la sangre periférica dentro de 3-4 semanas después del trasplante de médula ósea. <ol><li> Preparar tampón FACS (mM EDTA suero bovino fetal al 2 + 2% en PBS). NOTA: tampón FACS se puede almacenar a 4 ° C durante varias semanas. </li><li> Coloca el ratón en un tubo de restricción y afeitar el pelo de la pierna posterior para exponer la vena safena lateral. </li><li> Capa finamente la pierna con vaselina y perforar la vena safena con una aguja de 25 G. </li><li> Recoger aproximadamente 50 l de sangre con un tubo capilar recubierto con heparina. Añadir la sangre a un tubo de microcentrífuga que contiene 1 ml de tampón FACS. Mezclar el tubo por inversión y almacenar en hielo. </li><li> Mantenga gasa quirúrgica en el sitio de la inyección hasta que el sangrado se detiene antes de volver ratón de nuevo a la jaula. </li><li> Centrifugar las muestras de sangre durante 5 min a 900 x g. Retirar y desechar el sobrenadante. </li><li> Vuelva a suspender el sedimento en 500 l de tampón de lisis de los eritrocitos. Incubar en hielo durante 8,5 min. </li><li> Añadir 1 ml de tampón FACS para saciar el tampón de lisis. </li><li> Centrifugar las muestras durante 5 min a 900 x g. Retirar y desechar el sobrenadante. </li><li> Realizar una segunda etapa de lisis en 500 l de tampón de lisis de eritrocitos. Incubar en hielo durante 8,5 min. </li><li> Añadir 1 ml de tampón FACS para saciar el tampón de lisis. </li><li> Centrifugar las muestras durante 5 min a 900 x g. Retirar y desechar el sobrenadante. Compruebe que la pastilla es ahora blanco. NOTA: Si el pellet todavía aparece rojo, puede ser necesaria una etapa de lisis adicional antes de proceder al siguiente paso. </li><li> Vuelva a suspender el sedimento en 1 ml de tampón FACS. Centrifugar las muestras durante 5 min a 900 x g. Retirar y desechar el sobrenadante. </li><li> Vuelva a suspender el sedimento en 300 l de tampón FACS y cuantificar células GFP + mediante citometría de flujo (NOTA: En este punto cualquier inmunotinción deseada de las células se puede realizar, utilizando técnicas estándar, antes del análisis de citometría de flujo). </li></ol>

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The authors have nothing to disclose.

Acondicionado Busulfan permite la generación de alto nivel de quimerismo BM en ratones con células hematopoyéticas que son fácilmente detectable. Este acondicionamiento se puede realizar sin la necesidad de instalaciones de irradiación. Además, la mielosupresión con las dosis de busulfán se describe en este protocolo es bien tolerada, se minimizan los efectos secundarios tóxicos provocados por dosis mieloablativos de la irradiación, y por lo tanto puede ser una técnica más adecuada para generar BM quimerismo...

Recently, there has been considerable interest in the roles of microglia and bone marrow (BM)-derived cells (BMDCs) in the central nervous system (CNS), both during disease as well as with normal aging. Microglia, the resident immune cells of the CNS, are now known to develop in the CNS following the entry of primitive myeloid progenitors during embryogenesis1. Microglia retain aspects of their myelomonocytic lineage well into adult life. While evidence suggests that the contribution of BMDCs to the microglial pool is minimal in healthy adult animals1, the role BMDCs play in the progression of various neurodegenerative diseases remains unclear. This uncertainty is compounded by the fact that it is difficult to distinguish BMDCs that accumulate within the CNS from endogenous resident microglia, as no universally accepted discriminating immunohistochemical marker has been identified. In order to monitor BMDCs in vivo, we employ a BM transplantation (BMT) protocol whereby endogenous BM cells of a recipient mouse are replaced with those of a donor mouse ubiquitously expressing green fluorescent protein (GFP) under control of the &#946;-actin promoter. This protocol permits the determination of both the localization and morphology of GFP+ BMDCs within the recipient mouse using immunohistochemistry, and facilitates further characterization of these cells using fluorescence-activated cell sorting (FACS) followed by subsequent biochemical assays. 
For a successful BMT, recipient BM cells need to be ablated (termed myeloablation) in order to generate niche space within the recipient BM to allow for donor cell engraftment. Often, myeloablation is achieved using total body gamma irradiation which induces double strand breaks in DNA that leads to cell death, particularly in actively dividing cells such as hematopoietic progenitor cells2,3. The irradiation protocols are done to induce sufficient BM cell death such that animal lethality results if the recipient animal does not achieve adequate donor cell engraftment from BMT (so called &#8216;lethal irradiation&#8217;). However, irradiation requires a specialized facility and equipment, along with veterinary and animal husbandry resources not available to researchers at all institutions. Furthermore, myeloablative irradiation can cause potentially lethal damage to other tissues, and due to immunosuppresion, irradiated animals are more susceptible to secondary infections3. As such, reduced intensity conditioning (so called &#8216;RIC&#8217; protocols) regimens have been developed that are intended to minimize potentially toxic side effects of the conditioning protocol in patients, particularly for use in at risk populations such as children and the elderly4. 
Some RIC protocols rely upon chemotherapeutics such as busulfan in order to condition the BM compartment. Busulfan is a bifunctional DNA alkylating agent often used clinically as an alternative to irradiation5,6. Notably, busulfan can be safely administered to mice by intraperitoneal (IP) injection and does not require the specialized facilities and equipment necessary to irradiate mice. Busulfan conditioning has been used extensively in our lab7, as well as in several other recent publications8&#8211;11. When doses of 60-100 mg/kg are employed, high degrees of stable chimerism (>80% GFP+ cells) can be established in the peripheral blood and BM7. Importantly, at these doses myeloablation is not complete and as such mice are able to survive without receiving support BM cells (K. Peake, J. Manning, C. Lewis, and C. Krieger, unpublished observations). Moreover, with myelosuppressive busulfan conditioning there is rapid reconstitution of peripheral blood myelomonocytic cells by donor cells. However, the replacement of peripheral blood lymphocytes by donor cells is slower, highlighting the lack of immunosuppression that occurs with 60-100 mg/kg doses of busulfan compared to total body irradiation7. 
We have successfully used busulfan-induced chimerism to investigate BMDCs in wild-type mice, as well as in mouse models of the neurodegenerative disorders amyotrophic lateral sclerosis (ALS)7 and Alzheimer disease. It has been observed that under certain conditions significant numbers of GFP+ BMDCs accumulate within the CNS7,12. Importantly, like myeloablative conditioning with irradiation, busulfan conditioning followed by BMT is sufficient to allow for GFP+ BMDC accumulation within the CNS in both wild-type mice, and mice with neurological disorders7&#8211;11. As a major obstacle in treating neurodegenerative disorders is the ability to get therapeutic molecules from the circulation into the CNS where they can exert beneficial effects, this raises the possibility that BMDCs could be engineered to express therapeutic molecules, and subsequently used as a vehicle to deliver therapeutics to the CNS of busulfan conditioned recipients, a mechanism we are actively investigating. Although we have found that myeloablative conditioning with irradiation leads to greater accumulation of GFP+ BMDCs in the CNS compared to busulfan conditioning7, irradiation may have considerable toxicity in patients with neurodegenerative disorders and in murine models of CNS disease.
While we, and many others, have used BMT models to study BMDCs in neurodegenerative disorders, the ability to largely replace the BM compartment of a recipient mouse with a distinctly identifiable population of BM cells is an invaluable tool for studying various aspects of the hematopoietic system. This includes a wide array of research topics such as hematopoietic lineage development, leukemia, organ transplantation, graft-versus-host disease, and immunobiology.

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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name of Reagent/ Equipment</td>
			<td style="width:224px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Busulfex</td>
			<td style="width:224px;">Otsuka Canada Pharmaceutical Inc.</td>
			<td style="width:119px;">DIN 02240602</td>
			<td>Dilute busulfan to 3 mg/mL with sterile PBS just prior to use. Busulfan is cytotoxic. Handle and dispose according to the MSDS and institutional guidelines.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">ACK Lysing Buffer</td>
			<td style="width:224px;">Life Technologies</td>
			<td style="width:119px;">A10492-01</td>
			<td>Other lysis buffer could be substituted but incubation times may need to be adjusted accordingly</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Fetal Bovine Serum</td>
			<td style="width:224px;">Life Technologies</td>
			<td>12483-020</td>
			<td></td>
		</tr>
	</tbody>
</table>

busulfan as a myelosuppressive agent for generating stable high-level bone marrow chimerism in mice

Bone marrow transplantation (BMT) is often used to replace the bone marrow (BM) compartment of recipient mice with BM cells expressing a distinct biomarker isolated from donor mice. This technique allows for identification of donor-derived hematopoietic cells within the recipient mice, and can be used to isolate and characterize donor cells using various biochemical techniques. BMT typically relies on myeloablative conditioning with total body irradiation to generate niche space within the BM compartment of recipient mice for donor cell engraftment. The protocol we describe here uses myelosuppressive conditioning with the chemotherapeutic agent busulfan. Unlike irradiation, which requires the use of specialized facilities, busulfan conditioning is performed using intraperitoneal injections of 20 mg/kg busulfan until a total dose of 60-100 mg/kg has been administered. Moreover, myeloablative irradiation can have toxic side effects and requires successful engraftment of donor cells for survival of recipient mice. In contrast, busulfan conditioning using these doses is generally well tolerated and mice survive without donor cell support. Donor BM cells are isolated from the femurs and tibiae of mice ubiquitously expressing green fluorescent protein (GFP), and injected into the lateral tail vein of conditioned recipient mice. BM chimerism is estimated by quantifying the number of GFP+ cells within the peripheral blood following BMT. Levels of chimerism&nbsp;>80% are typically observed in the peripheral blood 3-4 weeks post-transplant and remain established for at least 1 year. As with irradiation, conditioning with busulfan and BMT allows for the accumulation of donor BM-derived cells within the central nervous system (CNS), particularly in mouse models of neurodegeneration. This busulfan-mediated CNS accumulation may be more physiological than total body irradiation, as the busulfan treatment is less toxic and CNS inflammation appears to be less extensive. We hypothesize that these cells can be genetically engineered to deliver therapeutics to the CNS.

La administración de 60-100 mg / kg de busulfan es generalmente bien tolerada por los ratones. Sin embargo, los animales suelen perder peso durante la fase de acondicionamiento (~ 10.5%) y por lo tanto la dieta puede ser necesario complementar con golosinas como las semillas de girasol irradiadas para promover la alimentación. Los niveles de quimerismo de&gt; 80% GFP + células en la sangre periférica y BM deben ser sistemáticamente alcanzable utilizando 60-100 mg / kg busulfán 7. Nuestro laboratorio ha ...

Watch this Scientific Journal Video about Busulfan as a Myelosuppressive Agent for Generating Stable High-level Bone Marrow Chimerism in Mice at JoVE.com

Busulfan as a Myelosuppressive Agent for Generating Stable High-level Bone Marrow Chimerism in Mice

We describe a protocol whereby busulfan conditioning permits the bone marrow of a recipient mouse to be replaced with bone marrow cells from donor mice ubiquitously expressing green fluorescent protein, in the absence of irradiation. This technique is useful to study bone marrow cell accumulation in the central nervous system.

El busulfán como agente mielosupresor para Generación estable de alto nivel de Médula Ósea quimerismo en ratones

Bone marrow transplantation (BMT) is often used to replace the bone marrow (BM) compartment of recipient mice with BM cells expressing a distinct ...

busulfan-as-myelosuppressive-agent-for-generating-stable-high-level

Research

JoVE Journal

Medicine

13.1K vistas.  Simon Fraser University. We describe a protocol whereby busulfan conditioning permits the bone marrow of a recipient mouse to be replaced with bone marrow cells from donor mice ubiquitously expressing green fluorescent protein, in the absence of irradiation. This technique is useful to study bone marrow cell accumulation in the central nervous system.

Video: Busulfan as a Myelosuppressive Agent for Generating Stable High-level Bone Marrow Chimerism in Mice

Pre-clinical Evaluation of Tyrosine Kinase Inhibitors for Treatment of Acute Leukemia

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are attractive druggable therapeutic targets. Here we describe an efficient four-step strategy for pre-clinical evaluation of tyrosine kinase inhibitors (TKIs) in the treatment of acute leukemia. Initially, western blot analysis is used to confirm target inhibition in cultured leukemia cells. Functional activity is then evaluated using clonogenic assays in methylcellulose or soft agar cultures. Experimental compounds that demonstrate activity in cell culture assays are evaluated in vivo using NOD-SCID-gamma (NSG) mice transplanted orthotopically with human leukemia cell lines. Initial in vivo pharmacodynamic studies evaluate target inhibition in leukemic blasts isolated from the bone marrow. This approach is used to determine the dose and schedule of administration required for effective target inhibition. Subsequent studies evaluate the efficacy of the TKIs in vivo using luciferase expressing leukemia cells, thereby allowing for non-invasive bioluminescent monitoring of leukemia burden and assessment of therapeutic response using an in vivo bioluminescence imaging system. This strategy has been effective for evaluation of TKIs in vitro and in vivo and can be applied for identification of molecularly-targeted agents with therapeutic potential or for direct comparison and prioritization of multiple compounds.

Receptor tyrosine kinases are ectopically expressed in many cancers and have been identified as therapeutic targets in acute leukemia. This manuscript describes an efficient strategy for pre-clinical evaluation of tyrosine kinase inhibitors for the treatment of acute leukemia.

Evaluación previa a la clínica de inhibidores de tirosina cinasa para el tratamiento de la leucemia aguda

Receptor tyrosine kinases have been implicated in the development and progression of many cancers, including both leukemia and solid tumors, and are ...

Investigación

Medicina

A Three-dimensional Tissue Culture Model to Study Primary Human Bone Marrow and its Malignancies

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods rely on the ability of cells either to attach to a solid substratum of a tissue culture dish or to grow in suspension in liquid medium. Multiple immortal cell lines have been created and grown using such approaches, however, these methods frequently fail when primary cells need to be grown ex vivo. Such failure has been attributed to the absence of the appropriate extracellular matrix components of the tissue microenvironment from the standard systems where tissue culture plastic is used as a surface for cell growth. Extracellular matrix is an integral component of the tissue microenvironment and its presence is crucial for the maintenance of physiological functions such as cell polarization, survival, and proliferation. Here we present a 3-dimensional tissue culture method where primary bone marrow cells are grown in extracellular matrix formulated to recapitulate the microenvironment of the human bone (rBM system). Embedded in the extracellular matrix, cells are supplied with nutrients through the medium supplemented with human plasma, thus providing a comprehensive system where cell survival and proliferation can be sustained for up to 30 days while maintaining the cellular composition of the primary tissue. Using the rBM system we have successfully grown primary bone marrow cells from normal donors and patients with amyloidosis, and various hematological malignancies. The rBM system allows for direct, in-matrix real time visualization of the cell behavior and evaluation of preclinical efficacy of novel therapeutics. Moreover, cells can be isolated from the rBM and subsequently used for in vivo transplantation, cell sorting, flow cytometry, and nucleic acid and protein analysis. Taken together, the rBM method provides a reliable system for the growth of primary bone marrow cells under physiological conditions.

In standard culture methods cells are taken out of their physiological environment and grown on the plastic surface of a dish. To study the behavior of primary human bone marrow cells we created a 3-D culture system where cells are grown under conditions recapitulating the native microenvironment of the tissue.

Un tejido tridimensional Cultura modelo para estudiar primaria médula ósea humana y sus malignidades

Tissue culture has been an invaluable tool to study many aspects of cell function, from normal development to disease. Conventional cell culture methods ...

Urinary Bladder Distention Evoked Visceromotor Responses as a Model for Bladder Pain in Mice

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized by increased urgency and frequency of urination, as well as nocturia and general pelvic pain, especially upon bladder filling or voiding. Despite years of research, the cause of IC/BPS remains elusive and treatment strategies are unable to provide complete relief to patients. In order to study nervous system contributions to the condition, many animal models have been developed to mimic the pain and symptoms associated with IC/BPS. One such murine model is urinary bladder distension (UBD). In this model, compressed air of a specific pressure is delivered to the bladder of a lightly anesthetized animal over a set period of time. Throughout the procedure, wires in the superior oblique abdominal muscles record electrical activity from the muscle. This activity is known as the visceromotor response (VMR) and is a reliable and reproducible measure of nociception. Here, we describe the steps necessary to perform this technique in mice including surgical manipulations, physiological recording, and data analysis. With the use of this model, the coordination between primary sensory neurons, spinal cord secondary afferents, and higher central nervous system areas involved in bladder pain can be unraveled. This basic science knowledge can then be clinically translated to treat patients suffering from IC/BPS.

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized in part by pelvic pain. In order to study nervous system contributions to the condition, a physiological model of urinary bladder pain is used in mice and rats.

Las respuestas de la Vejiga Urinaria Distensión Evocados visceromotor como modelo para la vejiga Dolor en ratones

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition ...

Femoral Bone Marrow Aspiration in Live Mice

Serial sampling of the cellular composition of bone marrow (BM) is a routine procedure critical to clinical hematology. This protocol describes a detailed step-by-step technical procedure for an analogous procedure in live mice which allows for serial characterization of cells present in the BM. This procedure facilitates studies aimed to detect the presence of exogenously administered cells within the BM of mice as would be done in xenograft studies for instance. Moreover, this procedure allows for the retrieval and characterization of cells enriched in the BM such as hematopoietic stem and progenitor cells (HSPCs) without sacrifice of mice. Given that the cellular composition of peripheral blood is not necessarily reflective of proportions and types of stem and progenitor cells present in the marrow, procedures which provide access to this compartment without requiring termination of the mice are very helpful. The use of femoral bone marrow aspiration is illustrated here for cytological analysis of marrow cells, flow cytometric characterization of the hematopoietic stem/progenitor compartment, and culture of sorted HSPCs obtained by femoral BM aspiration compared with conventional marrow harvest.

This protocol describes a procedure for serial sampling of femoral bone marrow (BM) without requiring the sacrifice of mice. This procedure facilitates longitudinal studies of the BM composition of mice over time and provides serial access to cells within the BM for ex vivo and transplantation studies.

Femoral Aspiración de médula ósea en ratones vivos

Serial sampling of the cellular composition of bone marrow (BM) is a routine procedure critical to clinical hematology. This protocol describes a detailed ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

Infusiones de la arteria carótida para farmacocinéticas y farmacodinámicas Análisis de taxanos en ratones

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

An In Vitro Dormancy Model of Estrogen-sensitive Breast Cancer in the Bone Marrow: A Tool for Molecular Mechanism Studies and Hypothesis Generation

The study of breast cancer dormancy in the bone marrow is an exceptionally difficult undertaking due to the complexity of the interactions of dormant cells with their microenvironment, their rarity and the overwhelming excess of hematopoietic cells. Towards this end, we developed an in vitro 2D clonogenic model of dormancy of estrogen-sensitive breast cancer cells in the bone marrow. The model consists of a few key elements necessary for dormancy. These include 1) the use of estrogen sensitive breast cancer cells, which are the type likely to remain dormant for extended periods, 2) incubation of cells at clonogenic density, where the structural interaction of each cell is primarily with the substratum, 3) fibronectin, a key structural element of the marrow and 4) FGF-2, a growth factor abundantly synthesized by bone marrow stromal cells and heavily deposited in the extracellular matrix. Cells incubated with FGF-2 form dormant clones after 6 days, which consist of 12 or less cells that have a distinct flat appearance, are significantly larger and more spread out than growing cells and have large cytoplasm to nucleus ratios. In contrast, cells incubated without FGF-2 form primarily growing colonies consisting of >30 relatively small cells. Perturbations of the system with antibodies, inhibitors, peptides or nucleic acids on day 3 after incubation can significantly affect various phenotypic and molecular aspects of the dormant cells at 6 days and can be used to assess the roles of membrane-localized or intracellular molecules, factors or signaling pathways on the dormant state or survival of dormant cells. While recognizing the in vitro nature of the assay, it can function as a highly useful tool to glean significant information about the molecular mechanisms necessary for establishment and survival of dormant cells. This data can be used to generate hypotheses to be tested in vivo models.

An In Vitro Dormancy Model of Estrogen-sensitive Breast Cancer in the Bone Marrow: A Tool for Molecular Mechanism Studies and Hypothesis Generation

We developed an in vitro model of dormancy in the bone marrow for estrogen-sensitive breast cancer cells. The goal of this protocol is to demonstrate use of the model for the study of the molecular and cellular biology of dormancy and for generation of hypotheses for subsequent testing in vivo.

Un<em&gt; In Vitro</em&gt; Latencia Modelo de cáncer de mama estrógeno-sensibles en la médula ósea: una herramienta de Estudios mecanismo molecular y Hipótesis Generación

The study of breast cancer dormancy in the bone marrow is an exceptionally difficult undertaking due to the complexity of the interactions of dormant ...

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

Recent advances in the application of bone marrow mesenchymal stem cells (BMMSC) for the treatment of tendon and ligament injuries in the horse suggest improved outcome measures in both experimental and clinical studies. Although the BMMSC are implanted into the tendon lesion in large numbers (usually 10 - 20 million cells), only a relatively small number survive (&#60;10%) although these can persist for up to 5 months after implantation. This appears to be a common observation in other species where BMMSC have been implanted into other tissues and it is important to understand when this loss occurs, how many survive the initial implantation process and whether the cells are cleared into other organs. Tracking the fate of the cells can be achieved by radiolabeling the BMMSC prior to implantation which allows non-invasive in vivo imaging of cell location and quantification of cell numbers.
This protocol describes a cell labeling procedure that uses Technetium-99m (Tc-99m), and tracking of these cells following implantation into injured flexor tendons in horses. Tc-99m is a short-lived (t1/2 of 6.01 hr) isotope that emits gamma rays and can be internalized by cells in the presence of the lipophilic compound hexamethylpropyleneamine oxime (HMPAO). These properties make it ideal for use in nuclear medicine clinics for the diagnosis of many different diseases. The fate of the labeled cells can be followed in the short term (up to 36 hr) by gamma scintigraphy to quantify both the number of cells retained in the lesion and distribution of the cells into lungs, thyroid and other organs. This technique is adapted from the labeling of blood leukocytes and could be utilized to image implanted BMMSC in other organs.

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

This protocol describes the radiolabeling of equine mesenchymal stem cells and their implantation into tendon injuries in the horse in order to determine cell survival and tissue distribution using gamma scintigraphy.

En vivo de imágenes y Seguimiento de tecnecio-99m Etiquetada células madre mesenquimales de médula ósea en Equinos tendinopatía

Recent advances in the application of bone marrow mesenchymal stem cells (BMMSC) for the treatment of tendon and ligament injuries in the horse suggest ...

Database-guided Flow-cytometry for Evaluation of Bone Marrow Myeloid Cell Maturation

A working group initiated within the French Cytometry Association (AFC) was developed in order to harmonize the application of multiparameter flow cytometry (MFC) for myeloid disease diagnosis in France. The protocol presented here was agreed-upon and applied between September 2013 and November 2015 in six French diagnostic laboratories (University Hospitals of Saint-Etienne, Grenoble, Clermont-Ferrand, Nice, and Lille and Institut Paoli-Calmettes in Marseille) and allowed the standardization of bone marrow sample preparation and data acquisition. Three maturation databases were developed for neutrophil, monocytic, and erythroid lineages with bone marrow from "healthy" donor individuals (individuals without any evidence of a hematopoietic disease). A robust method of analysis for each myeloid lineage should be applicable for routine diagnostic use. New cases can be analyzed in the same manner and compared against the usual databases. Thus, quantitative and qualitative phenotypic abnormalities can be identified and those above 2SD compared with data of normal bone marrow samples should be considered indicative of pathology. The major limitation is the higher variability between the data achieved using the monoclonal antibodies obtained with the methods based on hybridoma technologies and currently used in clinical diagnosis. Setting criteria for technical validation of the data acquired may help improve the utility of MFC for MDS diagnostics. The establishment of these criteria requires analysis against a database. The reduction of investigator subjectivity in data analysis is an important advantage of this method.

The MDS diagnosis is difficult in the absence of morphological criteria or non-informative cytogenetics. MFC could help refine the MDS diagnostic process. To become useful for clinical practice, the MFC analysis must be based on parameters with sufficient specificity and sensitivity, and data should be reproducible between different operators.

Guiada por la base de datos-citometría de flujo para la evaluación de la maduración de células mieloides de la médula

A working group initiated within the French Cytometry Association (AFC) was developed in order to harmonize the application of multiparameter flow ...

Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of the fresh gas entering a lung region divided by the region&#8217;s end-expiratory volume &#8213; in the human lung, using only inhaled oxygen as a contrast agent. Regional quantification of specific ventilation has the potential to help identify areas of pathologic lung function. Oxygen in solution in tissue shortens the tissue&#8217;s longitudinal relaxation time (T1), and thus a change in tissue oxygenation can be detected as a change in T1-weighted signal with an inversion recovery acquired image. Following an abrupt change between two concentrations of inspired oxygen, the rate at which lung tissue within a voxel equilibrates to a new steady-state reflects the rate at which resident gas is being replaced by inhaled gas. This rate is determined by specific ventilation. To elicit this sudden change in oxygenation, subjects alternately breathe 20-breath blocks of air (21% oxygen) and 100% oxygen while in the MRI scanner. A stepwise change in inspired oxygen fraction is achieved through use of a custom three-dimensional (3D)-printed flow bypass system with a manual switch during a short end-expiratory breath hold. To detect the corresponding change in T1, a global inversion pulse followed by a single shot fast spin echo sequence was used to acquire two-dimensional T1-weighted images in a 1.5&#160;T MRI scanner, using an eight-element torso coil. Both single slice and multi-slice imaging are possible, with slightly different imaging parameters. Quantification of specific ventilation is achieved by correlating the time-course of signal intensity for each lung voxel with a library of simulated responses to the air/oxygen stimulus. SVI estimations of specific ventilation heterogeneity have been validated against multiple breath washout and proved to accurately determine the heterogeneity of the specific ventilation distribution.

Specific ventilation imaging is a functional magnetic resonance imaging technique that allows for quantification of regional specific ventilation in the human lung, using inhaled oxygen as a contrast agent. Here, we present a protocol to collect and analyze specific ventilation imaging data.

Mapeo cuantitativo de ventilación específica en el pulmón humano usando resonancia magnética de protones y oxígeno como agente de contraste

Specific ventilation imaging (SVI) is a functional magnetic resonance imaging technique capable of quantifying specific ventilation &#8213; the ratio of ...

Flow Cytometry Analysis of Immune Cell Subsets within the Murine Spleen, Bone Marrow, Lymph Nodes and Synovial Tissue in an Osteoarthritis Model

Osteoarthritis (OA) is one of the most prevalent musculoskeletal diseases, affecting patients suffering from pain and physical limitations. Recent evidence indicates a potential inflammatory component of the disease, with both T-cells and monocytes/macrophages potentially associated with the pathogenesis of OA. Further studies postulated an important role for subsets of both inflammatory cell lineages, such as Th1, Th2, Th17, and T-regulatory lymphocytes, and M1, M2, and synovium-tissue-resident macrophages. However, the interaction between the local synovial and systemic inflammatory cellular response and the structural changes in the joint is unknown. To fully understand how T-cells and monocytes/macrophages contribute towards OA, it is important to be able to quantitively identify these cells and their subsets simultaneously in synovial tissue, secondary lymphatic organs and systemically (the spleen and bone marrow). Nowadays, the different inflammatory cell subsets can be identified by a combination of cell-surface markers making multi-color flow cytometry a powerful technique in investigating these cellular processes. In this protocol, we describe detailed steps regarding the harvest of synovial tissue and secondary lymphatic organs as well as generation of single cell suspensions. Furthermore, we present both an extracellular staining assay to identify monocytes/macrophages and their subsets as well as an extra- and intra-cellular staining assay to identify T-cells and their subsets within the murine spleen, bone marrow, lymph nodes and synovial tissue. Each step of this protocol was optimized and tested, resulting in a highly reproducible assay that can be utilized for other surgical and non-surgical OA mouse models.

Here, we describe a detailed and reproducible flow cytometry protocol to identify monocyte/macrophage and T-cell subsets using both extra- and intracellular staining assays within the murine spleen, bone marrow, lymph nodes and synovial tissue, utilizing an established surgical model of murine osteoarthritis.

Análisis de citometría de flujo de subconjuntos de células inmunitarias dentro del bazo murino, médula ósea, ganglios linfáticos y tejido sinovial en un modelo de osteoartritis