Name: in vivo vascular permeability detection in mouse submandibular gland
Uploaded: 2022-08-04T14:00:00
Description: Watch this Scientific Journal Video about In Vivo Vascular Permeability Detection in Mouse Submandibular Gland at JoVE.com

Este estudio fue apoyado por la Fundación Nacional de Ciencias Naturales de China (subvenciones 31972908, 81991500, 81991502, 81771093 y 81974151) y la Fundación de Ciencias Naturales de Beijing (subvención 7202082).

Todos los procedimientos experimentales fueron aprobados por el Comité de Ética de Investigación Animal, Centro de Ciencias de la Salud de la Universidad de Pekín, y cumplieron con la Guía para el Cuidado y Uso de Animales de Laboratorio (Publicación NIH No. 85-23, revisada en 1996). Para el presente estudio se utilizaron ratones machos de tipo salvaje (WT) en el grupo de edad de 8-10 semanas. Los animales experimentales fueron tratados cuidadosamente para minimizar su dolor y malestar.
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<ol>
	<li>Carpenter, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+secretion,+components,+and+properties+of+saliva.">The secretion, components, and properties of saliva.</a> Annual Review of Food Science and Technology. 4, 267-276 (2013).</li><li>Garrett, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+proper+role+of+nerves+in+salivary+secretion:+A+review.">The proper role of nerves in salivary secretion: A review.</a> Journal of Dental Research. 66 (2), 387-397 (1987).</li><li>Berndt, P., 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=Tight+junction+proteins+at+the+blood-brain+barrier:+Far+more+than+claudin-5.">Tight junction proteins at the blood-brain barrier: Far more than claudin-5.</a> Cellular and Molecular Life Sciences. 76 (10), 1987-2002 (2019).</li><li>Cong, X., 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=Disruption+of+endothelial+barrier+function+is+linked+with+hyposecretion+and+lymphocytic+infiltration+in+salivary+glands+of+Sj&#246;gren's+syndrome.">Disruption of endothelial barrier function is linked with hyposecretion and lymphocytic infiltration in salivary glands of Sj&#246;gren's syndrome.</a> Biochimica et Biophysica Acta - Molecular Basis of Disease. 1864 (10), 3154-3163 (2018).</li><li>Helmchen, F., Denk, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deep+tissue+two-photon+microscopy.">Deep tissue two-photon microscopy.</a> Nature Methods. 2 (12), 932-940 (2005).</li><li>Zipfel, W. R., Williams, R. M., Webb, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonlinear+magic:+Multiphoton+microscopy+in+the+biosciences.">Nonlinear magic: Multiphoton microscopy in the biosciences.</a> Nature Biotechnology. 21 (11), 1369-1377 (2003).</li><li>Masedunskas, A., Sramkova, M., Weigert, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Homeostasis+of+the+apical+plasma+membrane+during+regulated+exocytosis+in+the+salivary+glands+of+live+rodents.">Homeostasis of the apical plasma membrane during regulated exocytosis in the salivary glands of live rodents.</a> Bioarchitecture. 1 (5), 225-229 (2011).</li><li>Masedunskas, A., 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=Role+for+the+actomyosin+complex+in+regulated+exocytosis+revealed+by+intravital+microscopy.">Role for the actomyosin complex in regulated exocytosis revealed by intravital microscopy.</a> Proceedings of the National Academy of Sciences of the United States of America. 108 (33), 13552-13557 (2011).</li><li>Balda, M. S., 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=Functional+dissociation+of+paracellular+permeability+and+transepithelial+electrical+resistance+and+disruption+of+the+apical-basolateral+intramembrane+diffusion+barrier+by+expression+of+a+mutant+tight+junction+membrane+protein.">Functional dissociation of paracellular permeability and transepithelial electrical resistance and disruption of the apical-basolateral intramembrane diffusion barrier by expression of a mutant tight junction membrane protein.</a> The Journal of Cell Biology. 134 (4), 1031-1049 (1996).</li><li>Enis, D. R., 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=Induction,+differentiation,+and+remodeling+of+blood+vessels+after+transplantation+of+Bcl-2-transduced+endothelial+cells.">Induction, differentiation, and remodeling of blood vessels after transplantation of Bcl-2-transduced endothelial cells.</a> Proceedings of the National Academy of Sciences of the United States of America. 102 (2), 425-430 (2005).</li><li>Wang, X., 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=Application+of+digital+subtraction+angiography+in+canine+hindlimb+arteriography.">Application of digital subtraction angiography in canine hindlimb arteriography.</a> Vascular. 30 (3), 474-480 (2022).</li><li>Trani, M., Dejana, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+insights+in+the+control+of+vascular+permeability:+vascular+endothelial-cadherin+and+other+players.">New insights in the control of vascular permeability: vascular endothelial-cadherin and other players.</a> Current Opinion in Hematology. 22 (3), 267-272 (2015).</li><li>Viazzi, F., 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=Vascular+permeability,+blood+pressure,+and+organ+damage+in+primary+hypertension.">Vascular permeability, blood pressure, and organ damage in primary hypertension.</a> Hypertension Research. 31 (5), 873-879 (2008).</li><li>Scheppke, L., 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=Retinal+vascular+permeability+suppression+by+topical+application+of+a+novel+VEGFR2/Src+kinase+inhibitor+in+mice+and+rabbits.">Retinal vascular permeability suppression by topical application of a novel VEGFR2/Src kinase inhibitor in mice and rabbits.</a> The Journal of Clinical Investigation. 118 (6), 2337-2346 (2008).</li><li>Blanchet, M. R., 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=Loss+of+CD34+leads+to+exacerbated+autoimmune+arthritis+through+increased+vascular+permeability.">Loss of CD34 leads to exacerbated autoimmune arthritis through increased vascular permeability.</a> Journal of Immunology. 184 (3), 1292-1299 (2010).</li><li>Egawa, G., Ono, S., Kabashima, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+Imaging+of+vascular+permeability+by+two-photon+microscopy.">Intravital Imaging of vascular permeability by two-photon microscopy.</a> Methods in Molecular Biology. 2223, 151-157 (2021).</li><li>Vestweber, D., Wessel, F., Nottebaum, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Similarities+and+differences+in+the+regulation+of+leukocyte+extravasation+and+vascular+permeability.">Similarities and differences in the regulation of leukocyte extravasation and vascular permeability.</a> Seminars in Immunopathology. 36 (2), 177-192 (2014).</li><li>Schulte, D., 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=Stabilizing+the+VE-cadherin-catenin+complex+blocks+leukocyte+extravasation+and+vascular+permeability.">Stabilizing the VE-cadherin-catenin complex blocks leukocyte extravasation and vascular permeability.</a> The EMBO Journal. 30 (20), 4157-4170 (2011).</li><li>Uhl, 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=A+novel+experimental+approach+for+in+vivo+analyses+of+the+salivary+gland+microvasculature.">A novel experimental approach for in vivo analyses of the salivary gland microvasculature.</a> Frontiers in Immunology. 11, 604470 (2020).</li></ol>

El mantenimiento y la regulación de la función de barrera endotelial son esenciales para la homeostasis vascular. Las células endoteliales y sus uniones intercelulares juegan un papel crítico en el mantenimiento y control de la integridad vascular12. La fuerza de corte del flujo sanguíneo, los factores de crecimiento y los factores inflamatorios pueden causar cambios en la permeabilidad vascular y, por lo tanto, participar en la ocurrencia y desarrollo de enfermedades sistémicas como hiperte...

Varias glándulas salivales producen saliva, que actúa principalmente como la primera línea de defensa contra las infecciones y ayuda a la digestión, desempeñando así un papel esencial en la salud oral y general1. El suministro de sangre es crucial para la secreción de las glándulas salivales, ya que proporciona constantemente agua, electrolitos y moléculas que forman la saliva primaria. La función de barrera endotelial, regulada por el complejo de unión estrecha (TJ), limita estricta y delicadamente la permeación de los capilares, que son altamente permeables al agua, solutos, proteínas e incluso células que se mueven desde los vasos sanguíneos circulantes hacia los tejidos de las glándulas salivales 2,3. Hemos encontrado previamente que la apertura de los TJ endoteliales en respuesta a un estímulo colinérgico facilita la secreción de saliva, mientras que el deterioro de la función de barrera endotelial está interrelacionado con la hiposecreción y la infiltración linfocítica en las glándulas submandibulares (SMG) en el síndrome de Sjögren4. Estos datos sugieren que la contribución de la función de barrera endotelial debe prestarse suficiente atención con respecto a una variedad de enfermedades de las glándulas salivales.
Un microscopio de escaneo láser de dos fotones es una herramienta poderosa para observar la dinámica de las células en el tejido intacto in vivo. Una de las ventajas de esta técnica es que la luz infrarroja cercana (NIR) tiene una penetración tisular más profunda que la luz visible o ultravioleta cuando las muestras son excitadas por NIR y no causa daño obvio a los tejidos en condiciones apropiadas 5,6. De hecho, las glándulas salivales son un tejido muy homogéneo y superficial, en el que las células acinares superficiales están a sólo unos 30 μm de distancia de la superficie de la glándula 7,8. Se ha demostrado que la microscopía confocal intravital puede estudiar la secreción exocrina y el citoesqueleto de actina en glándulas salivales de ratón vivas a resolución subcelular8. Sin embargo, la microscopía de barrido láser de dos fotones no solo tiene la ventaja de la microscopía confocal convencional, sino que también se puede usar para detectar tejidos e imágenes más profundos con mayor claridad. Aquí, los dextranos marcados con fluorescencia, que se utilizan con frecuencia como trazadores de permeabilidad paracelular y tienen la ventaja de diferentes tamaños, se pueden usar para probar la magnitud del poro TJ9. En el presente estudio, se establece una técnica intravital de microscopía de barrido láser de dos fotones en tiempo real para la evaluación in situ de la función de barrera endotelial en SMG de ratón. Cada paso de trabajo para la detección de permeabilidad vascular in vivo en SMG de ratón se describe en el protocolo actual. Aquí hay un ejemplo de detección de la función de barrera endotelial en el modelo de ligadura del conducto SMG del ratón.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2-photon microscope (TCS-SP8 DIVE)</td>
			<td>Leica, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>4 kDa FITC-labeled dextran</td>
			<td>Sigma Aldrich</td>
			<td>46944</td>
			<td></td>
		</tr>
		<tr>
			<td>70 kDa rhodamine B-labeled dextran</td>
			<td>Sigma Aldrich</td>
			<td>R9379</td>
			<td></td>
		</tr>
		<tr>
			<td>Blunt tissue separation nickel</td>
			<td>Bejinghuabo Company</td>
			<td>NZW28</td>
			<td></td>
		</tr>
		<tr>
			<td>Depilatory cream</td>
			<td>Veet</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable sterile syringe</td>
			<td>Zhiyu Company</td>
			<td></td>
			<td>1 mL</td>
		</tr>
		<tr>
			<td>Image J software</td>
			<td>National Institutes of Health</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Insulin syringe</td>
			<td>Becton, Dickinson and Company</td>
			<td>0253316</td>
			<td>1 mL</td>
		</tr>
		<tr>
			<td>Leica Application Suite X software</td>
			<td>Leica Microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microtubes</td>
			<td>Axygen</td>
			<td>MCT-150-C</td>
			<td>1.5 mL</td>
		</tr>
		<tr>
			<td>Phosphate buffered saline 1x</td>
			<td>Servicebio</td>
			<td>G4207-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue scissors</td>
			<td>Bejinghuabo Company</td>
			<td>M286-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Tribromoethanol</td>
			<td>JITIAN Bio</td>
			<td>JT0781</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vivo vascular permeability detection in mouse submandibular gland

La saliva juega un papel importante en la salud oral y general. La función de barrera endotelial intacta de los vasos sanguíneos permite la secreción de saliva, mientras que la disfunción de la barrera endotelial está relacionada con muchos trastornos secretores de las glándulas salivales. El presente protocolo describe un método de detección de permeabilidad paracelular in vivo para evaluar la función de las uniones estrechas endoteliales (TJ) en glándulas submandibulares de ratón (SMG). Primero, se inyectaron dextranos marcados con fluorescencia con diferentes pesos moleculares (4 kDa, 40 kDa o 70 kDa) en las venas angulares de ratones. Posteriormente, el SMG unilateral se diseccionó y fijó en el soporte personalizado bajo un microscopio de escaneo láser de dos fotones, y luego se capturaron imágenes de vasos sanguíneos, acinos y conductos. Utilizando este método, se monitorizó la fuga dinámica en tiempo real de los trazadores de diferentes tamaños de los vasos sanguíneos hacia los lados basales de los acinos e incluso a través del epitelio acinar hacia los conductos para evaluar la alteración de la función de barrera endotelial en condiciones fisiológicas o fisiopatológicas.

Siguiendo el protocolo, el SMG unilateral se unió a un soporte hecho a medida, y la glándula se mantuvo lo más lejos posible del cuerpo del ratón para evitar que la respiración causara artefactos de movimiento. El flujo rápido de los glóbulos rojos (puntos negros) en los vasos sanguíneos se observó bajo el microscopio. Después de encontrar el campo de tejido debajo de una lente ocular, uno debe cambiar para manipular el software del microscopio. En el grupo de control, ambos trazadores existían en los vasos sa...

Watch this Scientific Journal Video about In Vivo Vascular Permeability Detection in Mouse Submandibular Gland at JoVE.com

In Vivo Vascular Permeability Detection in Mouse Submandibular Gland

En el presente protocolo, la función de barrera endotelial de la glándula submandibular (SMG) se evaluó inyectando diferentes trazadores fluorescentes ponderados molecularmente en las venas angulares de modelos animales de prueba in vivo bajo un microscopio de escaneo láser de dos fotones.

In vivo Detección de permeabilidad vascular en glándula submandibular de ratón

Saliva plays an important role in oral and overall health. The intact endothelial barrier function of blood vessels enables saliva secretion, whereas the ...

El presente protocolo describe una medida de detección de permeabilidad paracelular in vivo para evaluar la función de las uniones endoteliales estrechas en glándulas submandibulares de ratón. Sin embargo, la microscopía de barrido láser de dos fotones no solo tiene la ventaja de la microscopía confocal convencional, sino que también se puede usar para detectar tejidos e imágenes más profundos con mayor claridad. Este experimento proporciona una buena medida de método para evaluar la permeabilidad vascular de diferentes tejidos, especialmente los tejidos superficiales y órganos de los animales.Comience eligiendo trazadores apropiados como fluoresceína, isotiocianato, dextrano marcado y rodamina B, marcado como dextrano con espectros de emisiones de excitación distintos, para minimizar la interferencia entre las señales de fluorescencia para el ensayo de permeabilidad. Diluir las trazas en solución salina tamponada con fosfato estéril en 100 miligramos por mililitro y almacenar las alícuotas protegidas de la luz a menos 20 grados centígrados. Después de anestesiar al ratón macho de tipo salvaje de 8 a 10 semanas de edad, sostenga suavemente la cabeza y el cuello del ratón para hacer que un lado del globo ocular sobresalga ligeramente.Inserte una jeringa de insulina que contenga 100 microlitros de mezcla de solución trazadora fluorescente a lo largo de la esquina del ojo en ángulo recto con el ojo. Después de la inyección, coloque rápidamente el ratón sobre el cartón en posición supina con las extremidades y la cabeza pegadas con cinta adhesiva. Para el aislamiento de la glándula submandibular o SMG, bajo un microscopio estereoscópico, corte la epidermis del cuello con tijeras de tejido general para exponer ambos lados de los SMG.Luego, use una aguja de separación de tejido romo para separar suavemente la cápsula de la superficie de la glándula sin dañar el tejido glandular, los vasos sanguíneos y la estructura glandular. Conecte el soporte personalizado al dispositivo de presión negativa y verifique si el efecto de presión negativa se logra correctamente de antemano. Coloque suavemente el SMG expuesto en el soporte personalizado y aspire el tejido mediante succión de presión negativa, lo más lejos posible del cuerpo del ratón, para reducir los artefactos de movimiento causados por la respiración y otras afecciones.Comience a tomar imágenes poco después de que se elija el sitio de la glándula. Adquiera imágenes secuenciales a lo largo del eje Z escalonadas dos micras de distancia de la superficie de la glándula hasta 70 a 140 micras en el tejido para generar una construcción tridimensional. A continuación, adquiera imágenes de lapso de tiempo de los vasos para medir la permeabilidad vascular en el SMG.En el cuadro de diálogo del Explorador, haga clic en Agregar nueva carpeta" y cambie el nombre del archivo. A continuación, vuelva a la columna de adquisición. En XY, el formato es de 512 por 512, y la velocidad es de 400 hercios.Active la X bidireccional, establezca el factor de zoom en 0,75 y 1,5 para el zoom. A continuación, seleccione XYT en Modo de adquisición" para adquirir imágenes de lapso de tiempo. Establezca la duración en 20 segundos, 30 minutos o más según la necesidad experimental.Después de establecer las condiciones, haga clic en "En vivo" para observar la imagen vascular de dos canales y canales superpuestos en el marco de formación de fotos y elegir las áreas de interés. Haga clic en Inicio" para comenzar la creación de imágenes. Ensayo de permeabilidad vascular in vivo e imágenes tridimensionales de vasos sanguíneos en ratones.Las glándulas submandibulares se muestran aquí. En el grupo control, ambos marcadores existían en los vasos sanguíneos del SMG. Debido a su pequeño peso molecular, FD4 fue capaz de filtrarse de los vasos sanguíneos a los lados basales de acinos y conductos, representando así claramente la forma de los acinos y conductos.El RD70 se distribuyó en vasos sanguíneos de gran tamaño y microvasos. En el grupo de ligadura de conductos, tanto FD4 como RD70 se extravasaron a los lados basales de los acinos, lo que indicó que la ligadura del conducto podría interrumpir la función de barrera endotelial y aumentar la permeabilidad a moléculas grandes. Además, los resultados semicuantitativos de intensidad de fluorescencia FD4 y RD70 confirmaron estas observaciones.Las imágenes tridimensionales mostraron una fluorescencia mucho más oscura de FD4 y RD70 alrededor de los vasos sanguíneos en el grupo de ligadura en comparación con el grupo de control. El aislamiento cuidadoso de SMG y la colocación adecuada y el microscopio son requisitos previos esenciales para una detección exitosa. Después de los procedimientos, la tasa de flujo sanguíneo se puede calcular combinando el movimiento de los glóbulos rojos y se puede perseguir la infiltración de las células sanguíneas marcadas con fluorescencia.

in-vivo-vascular-permeability-detection-in-mouse-submandibular-gland

Research

JoVE Journal

Biology

In Vivo Vascular Permeability Detection in Mouse Submandibular Gland

Single-cell Suction Recordings from Mouse Cone Photoreceptors

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment are open and allow cations to flow steadily inwards across the membrane, depolarizing the cell. Light exposure triggers the closure of the CNG channels, blocks the inward cation current flow, and thus results in cell hyperpolarization. Based on the polarity of photoreceptors, a suction recording method was developed in 1970s that, unlike the classic patch-clamp technique, does not require penetrating the plasma membrane 1. Drawing the outer segment into a tightly-fitting glass pipette filled with extracellular solution allows recording the current changes in individual cells upon test-flash exposure. However, this well-established "outer-segment-in (OS-in)" suction recording is not suitable for mouse cone recordings, because of the low percentage of cones in the mouse retina (3%) and the difficulties in identifying the cone outer segments. Recently, an inner-segment-in (IS-in) recording configuration was developed to draw the inner segment/nuclear region of the photoreceptor into the recording pipette 2,3. In this video, we will show how to record from individual mouse cone photoresponses using single-cell suction electrode.

We will show how to record flash responses from single mouse cones using a suction electrode.

Una sola célula grabaciones de succión de los conos del ratón

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment ...

Investigación

Biología

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

En vivo de imágenes y tratamientos terapéuticos en un modelo de ratón ortotópico de cáncer de ovario

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Isolation of Mouse Salivary Gland Stem Cells

Mature salivary glands of both human and mouse origin comprise a minimum of five cell types, each of which facilitates the production and excretion of saliva into the oral cavity. Serous and mucous acinar cells are the protein and mucous producing factories of the gland respectively, and represent the origin of saliva production. Once synthesised, the various enzymatic and other proteinaceous components of saliva are secreted through a series of ductal cells bearing epithelial-type morphology, until the eventual expulsion of the saliva through one major duct into the cavity of the mouth. The composition of saliva is also modified by the ductal cells during this process.
In the manifestation of diseases such as Sj&ouml;gren's syndrome, and in some clinical situations such as radiotherapy treatment for head and neck cancers, saliva production by the glands is dramatically reduced 1,2. The resulting xerostomia, a subjective feeling of dry mouth, affects not only the ability of the patient to swallow and speak, but also encourages the development of dental caries and can be socially debilitating for the sufferer.
The restoration of saliva production in the above-mentioned clinical conditions therefore represents an unmet clinical need, and as such several studies have demonstrated the regenerative capacity of the salivary glands 3-5. Further to the isolation of stem cell-like populations of cells from various tissues within the mouse and human bodies 6-8, we have shown using the described method that stem cells isolated from mouse salivary glands can be used to rescue saliva production in irradiated salivary glands 9,10. This discovery paves the way for the development of stem cell-based therapies for the treatment of xerostomic conditions in humans, and also for the exploration of the salivary gland as a microenvironment containing cells with multipotent self-renewing capabilities.

An optimized protocol for the isolation of stem cells from the mouse salivary gland is described. The method employs enzymatic and mechanical digestion, and permits isolation of salispheres containing cells with characteristics of stem cells.

Aislamiento de células de la glándula salival del ratón madre

Mature salivary glands of both human and mouse origin comprise a minimum of five cell types, each of which facilitates the production and excretion of ...

Evaluation of Mammary Gland Development and Function in Mouse Models

The human mammary gland is composed of 15-20 lobes that secrete milk into a branching duct system opening at the nipple. Those lobes are themselves composed of a number of terminal duct lobular units made of secretory alveoli and converging ducts1. In mice, a similar architecture is observed at pregnancy in which ducts and alveoli are interspersed within the connective tissue stroma. The mouse mammary gland epithelium is a tree like system of ducts composed of two layers of cells, an inner layer of luminal cells surrounded by an outer layer of myoepithelial cells denoted by the confines of a basement membrane2. At birth, only a rudimental ductal tree is present, composed of a primary duct and 15-20 branches. Branch elongation and amplification start at the beginning of puberty, around 4 weeks old, under the influence of hormones3,4,5. At 10 weeks, most of the stroma is invaded by a complex system of ducts that will undergo cycles of branching and regression in each estrous cycle until pregnancy2. At the onset of pregnancy, a second phase of development begins, with the proliferation and differentiation of the epithelium to form grape-shaped milk secretory structures called alveoli6,7. Following parturition and throughout lactation, milk is produced by luminal secretory cells and stored within the lumen of alveoli. Oxytocin release, stimulated by a neural reflex induced by suckling of pups, induces synchronized contractions of the myoepithelial cells around the alveoli and along the ducts, allowing milk to be transported through the ducts to the nipple where it becomes available to the pups 8. Mammary gland development, differentiation and function are tightly orchestrated and require, not only interactions between the stroma and the epithelium, but also between myoepithelial and luminal cells within the epithelium9,10,11. Thereby, mutations in many genes implicated in these interactions may impair either ductal elongation during puberty or alveoli formation during early pregnancy, differentiation during late pregnancy and secretory activation leading to lactation12,13. In this article, we describe how to dissect mouse mammary glands and assess their development using whole mounts. We also demonstrate how to evaluate myoepithelial contractions and milk ejection using an ex-vivo oxytocin-based functional assay. The effect of a gene mutation on mammary gland development and function can thus be determined in situ by performing these two techniques in mutant and wild-type control mice.

This method describes how to dissect and assess mammary gland development and function from mice. Excised mammary glands are assessed for the degree of development using whole mount while milk ejection is evaluated using an oxytocin-based myoepithelial cell contraction assay.

Evaluación de la glándula mamaria de desarrollo y función en modelos de ratón

The human mammary gland is composed of 15-20 lobes that secrete milk into a branching duct system opening at the nipple. Those lobes are themselves ...

Multi-parameter Measurement of the Permeability Transition Pore Opening in Isolated Mouse Heart Mitochondria

The mitochondrial permeability transition pore (mtPTP) is a non specific channel that forms in the inner mitochondrial membrane to transport solutes with a molecular mass smaller than 1.5 kDa. Although the definitive molecular identity of the pore is still under debate, proteins such as cyclophilin D, VDAC and ANT contribute to mtPTP formation. While the involvement of mtPTP opening in cell death is well established1, accumulating evidence indicates that the mtPTP serves a physiologic role during mitochondrial Ca2+ homeostasis2, bioenergetics and redox signaling 3.
mtPTP opening is triggered by matrix Ca2+ but its activity can be modulated by several other factors such as oxidative stress, adenine nucleotide depletion, high concentrations of Pi, mitochondrial membrane depolarization or uncoupling, and long chain fatty acids4. In vitro, mtPTP opening can be achieved by increasing Ca2+ concentration inside the mitochondrial matrix through exogenous additions of Ca2+ (calcium retention capacity). When Ca2+ levels inside mitochondria reach a certain threshold, the mtPTP opens and facilitates Ca2+ release, dissipation of the proton motive force, membrane potential collapse and an increase in mitochondrial matrix volume (swelling) that ultimately leads to the rupture of the outer mitochondrial membrane and irreversible loss of organelle function.
Here we describe a fluorometric assay that allows for a comprehensive characterization of mtPTP opening in isolated mouse heart mitochondria. The assay involves the simultaneous measurement of 3 mitochondrial parameters that are altered when mtPTP opening occurs: mitochondrial Ca2+ handling (uptake and release, as measured by Ca2+ concentration in the assay medium), mitochondrial membrane potential, and mitochondrial volume. The dyes employed for Ca2+ measurement in the assay medium and mitochondrial membrane potential are Fura FF, a membrane impermeant, ratiometric indicator which undergoes a shift in the excitation wavelength in the presence of Ca2+, and JC-1, a cationic, ratiometric indicator which forms green monomers or red aggregates at low and high membrane potential, respectively. Changes in mitochondrial volume are measured by recording light scattering by the mitochondrial suspension. Since high-quality, functional mitochondria are required for the mtPTP opening assay, we also describe the steps necessary to obtain intact, highly coupled and functional isolated heart mitochondria.

A spectrofluorometric protocol for the measurement of the mitochondrial permeability transition pore opening in isolated mouse heart mitochondria is presented here. The assay involves the simultaneous measurement of mitochondria Ca2+ handling, mitochondrial membrane potential and mitochondrial volume. The procedure for obtaining high-quality and functional heart mitochondria is also described.

Multi-parámetro de medición de la apertura del poro de transición de permeabilidad en el corazón del ratón mitocondrias aisladas

The mitochondrial permeability transition pore (mtPTP) is a non specific channel that forms in the inner mitochondrial membrane to transport solutes with ...

Intraductal Injection for Localized Drug Delivery to the Mouse Mammary Gland

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of genes within the mammary epithelium has been difficult to achieve due to the lack of appropriate targeting molecules that are independent of developmental stages such as pregnancy and lactation. Herein, we describe a technique for localized delivery of reagents to the mammary gland at any stage in adulthood via intraductal injection into the nipples of mice. The injections can be performed on live mice, under anesthesia, and allow for a non-invasive and localized drug delivery to the mammary gland. Furthermore, the injections can be repeated over several months without damaging the nipple. Vital dyes such as Evans Blue are very helpful to learn the technique. Upon intraductal injection of the blue dye, the entire ductal tree becomes visible to the eye. Furthermore, fluorescently labeled reagents also allow for visualization and distribution within the mammary gland. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents, and small molecules.

A protocol for the non-invasive intraductal delivery of aqueous reagents to the mouse mammary gland is described. The method takes advantage of localized injection into the nipples of mammary glands targeting mammary ducts specifically. This technique is adaptable for a variety of compounds including siRNA, chemotherapeutic agents and small molecules.

Inyección intraductal de entrega de la droga localizada a la glándula mamaria de ratón

Herein we describe a protocol to deliver various reagents to the mouse mammary gland via intraductal injections. Localized drug delivery and knock-down of ...

Measuring the Osmotic Water Permeability Coefficient (Pf) of Spherical Cells: Isolated Plant Protoplasts as an Example

Studying AQP regulation mechanisms is crucial for the understanding of water relations at both the cellular and the whole plant levels. Presented here is a simple and very efficient method for the determination of the osmotic water permeability coefficient (Pf) in plant protoplasts, applicable in principle also to other spherical cells such as frog oocytes. The first step of the assay is the isolation of protoplasts from the plant tissue of interest by enzymatic digestion into a chamber with an appropriate isotonic solution. The second step consists of an osmotic challenge assay: protoplasts immobilized on the bottom of the chamber are submitted to a constant perfusion starting with an isotonic solution and followed by a hypotonic solution. The cell swelling is video recorded. In the third step, the images are processed offline to yield volume changes, and the time course of the volume changes is correlated with the time course of the change in osmolarity of the chamber perfusion medium, using a curve fitting procedure written in Matlab (the &#8216;PfFit&#8217;), to yield Pf.

Measuring the Osmotic Water Permeability Coefficient Pf of Spherical Cells: Isolated Plant Protoplasts as an Example

Measuring the osmotic water permeability coefficient (Pf) of cells can help understand the regulatory mechanisms of aquaporins (AQPs). Pf determination in spherical plant cell protoplasts presented here involves protoplasts isolation and numerical analysis of their initial rate of volume change as a result of an osmotic challenge during constant bath perfusion.

Medición de la osmótica de agua Coeficiente de Permeabilidad (P<sub&gt; F</sub&gt;) De células esféricas: protoplastos de plantas aisladas como ejemplo

Studying AQP regulation mechanisms is crucial for the understanding of water relations at both the cellular and the whole plant levels. Presented here is ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

La medición de la rigidez de<em&gt; Ex Vivo</em&gt; Ratón aortas Usando microscopía de fuerza atómica

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells

The post-translational modifications of proteins are critical for the proper regulation of intracellular signal transduction. Among these modifications, small ubiquitin-related modifier (SUMO) is a ubiquitin-like protein that is covalently attached to the lysine residues of a variety of target proteins to regulate cellular processes, such as gene transcription, DNA repair, protein interaction and degradation, subcellular transport, and signal transduction. The most common approach to detecting protein SUMOylation is based on the expression and purification of recombinant tagged proteins in bacteria, allowing for an in vitro biochemical reaction which is simple and suitable for addressing mechanistic questions. However, due to the complexity of the process of SUMOylation in vivo, it is more challenging to detect and analyze protein SUMOylation in cells, especially when under endogenous conditions. A recent study by the authors of this paper revealed that endogenous retinoblastoma (Rb) protein, a tumor suppressor that is vital to the negative regulation of the cell cycle progression, is specifically SUMOylated at the early G1 phase. This paper describes a protocol for the detection and analysis of Rb SUMOylation under both endogenous and exogenous conditions in human cells. This protocol is appropriate for the phenotypical and functional investigation of the SUMO-modification of Rb, as well as many other SUMO-targeted proteins, in human cells.

In Vivo Detection and Analysis of Rb Protein SUMOylation in Human Cells

Small ubiquitin-related modifier (SUMO) family proteins are conjugated to the lysine residues of target proteins to regulate various cellular processes. This paper describes a protocol for the detection of retinoblastoma (Rb) protein SUMOylation under endogenous and exogenous conditions in human cells.

En Vivo Detección y análisis de la sumoilación de la proteína Rb en células humanas

The post-translational modifications of proteins are critical for the proper regulation of intracellular signal transduction. Among these modifications, ...

In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability

The intestinal barrier defends against pathogenic microorganism and microbial toxin. Its function is regulated by tight junction permeability and epithelial cell integrity, and disruption of the intestinal barrier function contributes to progression of gastrointestinal and systemic disease. Two simple methods are described here to measure the permeability of intestinal epithelium. In vitro, Caco-2BBe cells are plated in tissue culture wells as a monolayer and transepithelial electrical resistance (TER) can be measured by an epithelial (volt/ohm) meter. This method is convincing because of its user-friendly operation and repeatability. In vivo, mice are gavaged with 4 kDa fluorescein isothiocyanate (FITC)-dextran, and the FITC-dextran concentrations are measured in collected serum samples from mice to determine the epithelial permeability. Oral gavage provides an accurate dose, and therefore is the preferred method to measure the intestinal permeability in vivo. Taken together, these two methods can measure the permeability of the intestinal epithelium in vitro and in vivo, and hence be used to study the connection between diseases and barrier function.

In Vitro and In Vivo Approaches to Determine Intestinal Epithelial Cell Permeability

Two methods are presented here to determine intestinal barrier function. An epithelial meter (volt/ohm) is used for measurements of transepithelial electrical resistance of cultured epithelia directly in tissue culture wells. In mice, the FITC-dextran gavage method is used to determine the intestinal permeability in vivo.