We thank Amanda Fair, the CMI, and Kathy Sweet and the ORL at UM for assistance with &#181;CT imaging and analysis. Funding: BL Funded by 1K08GM109105-01 and Plastic Surgery Foundation National Endowment Award.

Declaración de Ética: Todos los animales procedimientos se llevaron a cabo en estricta conformidad con las buenas prácticas de los animales como se define en las directrices establecidas en la Guía para el Uso y Cuidado de Animales de Laboratorio: Octava edición del Instituto de Investigación de Animales de Laboratorio (ILAR, 2011) y fueron aprobado por el Comité de Cuidado y Uso de Animales Institucional de la Universidad de Michigan (PRO0001553). 1. Ratón Procedimientos Quirúrgicos NOTA: El uso de 8-10 semanas de edad C57BL / 6 ratones. Otros edades, orígenes y cepas de ratones también se pueden utilizar para probar diferentes condiciones o genética. Para la parte tenotomía del procedimiento, mantener condiciones estériles usando mascarilla, capo de cabello y bata estéril, guantes, y los instrumentos. Sitios quirúrgicos se deben preparar de forma estéril con povidona yodada y drapeado estéril. Evite la hipotermia utilizando una almohadilla térmica veterinaria y el calentamiento de soluciones de reanimación a 37 ° C antes de ADMINISTRAción. <ol><li> Anestesiar al ratón usando 2,5% de isoflurano inhalado. Use un cono de la nariz para dejar el dorso y extremidades traseras de fácil acceso. Ajustar la velocidad de administración de isoflurano para mantener la tasa respiratoria apropiada y la coloración de las membranas mucosas y para asegurar la anestesia mediante la comprobación del tono muscular, pizca dedo del pie, y el reflejo corneal. Aplicar pomada oftálmica sosa para los ojos del ratón para evitar lesiones en los ojos secos durante el procedimiento. Mantener la temperatura corporal adecuada utilizando una almohadilla térmica veterinaria o caliente de recirculación de agua debajo del campo quirúrgico. </li><li> Administrar buprenorfina, 0.1 mg / kg, por vía subcutánea inmediatamente antes de la cirugía para la analgesia. </li><li> Estrechamente afeitar el sitio quirúrgico en la pata trasera izquierda usando máquinas de cortar desde el talón hasta la rodilla. </li><li> Estrechamente afeitar el dorso del ratón, comenzando sobre la columna vertebral y que se extiende el área afeitada a la izquierda de la línea media dorsal, la limpieza de un área de al menos 2 cm x 3 cm para acomodar la lesión por quemadura. </li><li>Preparar el lugar de la cirugía, incluyendo la pata trasera de la rodilla utilizando 3 alternas friega-povidona yodada. </li><li> Realice una incisión longitudinal a lo largo de la cara medial del tendón de Aquiles izquierdo. Extienda la incisión por lo que el tendón de Aquiles se puede visualizar fácilmente; aproximadamente 0,5 cm. </li><li> Realizar una tenotomía de Aquiles con disección aguda del tendón en el punto medio con unas tijeras afiladas tejido. Inserte una hoja de la tijera de tejido en el plano de tejido debajo de la tendón y diseccionar lo largo del plano hasta que la hoja es en el punto medio del tendón. Cierre las hojas de las tijeras para cortar el tendón bruscamente. NOTA: Asegúrese de que la inclusión de todos los tendones posteriores incluyendo gastrocnemio, sóleo y tendones Plantaris. </li><li> Lograr la hemostasia mediante la aplicación de presión con una gasa estéril (debe haber sangrado mínimo) y cerrar la incisión de la piel con una puntada 5-0 vicryl. </li><li> Realice el dorsal quemadura de espesor parcial con un bloque de aluminio con un peso de 35 g con MEDICIÓN aproximadasts 2 cm x 2 cm x 3 cm se calentó a 60 ° C en un baño de agua aplicada a la dorso afeitada del ratón para 17 seg. NOTA: Lograr la profundidad de la quemadura apropiado por el bloque descansando en la parte superior del ratón anestesiado, asegurando que toda el área de superficie del bloque se encuentra en contacto con el ratón, sin embargo evitar la aplicación de cualquier presión adicional para el bloque, es decir, permitir que la gravedad para ser la única fuerza que sostiene el bloque en su lugar. Un mango de plástico delgado unido a un lado del bloque es conveniente para la manipulación, la estabilización y recuperación del baño de agua caliente. Esto creará un área de superficie corporal total, aproximadamente el 30% se quema en un 8-10 semanas de edad C57BL / 6 mouse. Esta quemadura contacto fue elegido sobre otros métodos (llama quemadura o escaldadura) debido a la uniformidad de la profundidad de la quemadura sobre la herida y la reproducibilidad entre los animales. </li><li> Seque el lugar de la quemadura con una gasa y aplicar un apósito Tegaderm. </li><li> Administrar fluidos de resucitación calentado: Ringer lactato solución de 1 mlinyección intraperitoneal y 0,5 ml de la inyección subcutánea. Esta administración de una sola vez de la reanimación es adecuado para la recuperación de la lesión por quemadura y tenotomía. NOTA: No devuelva ratones anestesiados a las jaulas de vivienda con otros ratones, casa individualmente en jaulas limpias bajo vigilancia hasta que los ratones están totalmente recuperados. Recuperación típica se produce dentro de 1-6 horas. Sitios de quemaduras generalmente sanan dentro de 2-4 semanas y rara vez se complican por infección de la herida si se mantiene en entornos de vivienda limpias. </li><li> Administrar buprenorfina 0,1 mg inyección subcutánea / kg cada 12 horas durante 3 días después del procedimiento. Monitorear el crecimiento HO con exploraciones μCT serie a intervalos apropiados. El crecimiento del hueso ectópico es evidente por primera vez alrededor de 3 semanas después de la operación por μCT. NOTA: La mayoría de desarrollo HO es completa por 9 semanas después de la operación. No hemos observado una diferencia en el volumen de HO o ubicación con repetidas μCT escanea dos veces por semana durante 15 semanas en comparación a un solo punto final μCT escanear a las 15 semanas.Al final de los experimentos, la eutanasia de todos los ratones con inhalación de CO2 de acuerdo con las directrices institucionales y comprobar la muerte con dislocación cervical después de 10 min. </li></ol> 2. μCT Adquisición y Análisis <ol><li> Asegure el ratón anestesiado en el escáner en la posición prona. Pegue las patas traseras firmemente a la cama para evitar respirar artefacto de movimiento. Incluya el aire, el agua y la hidroxiapatita contiene fantasma bajo el ratón para la calibración de imagen. </li><li> Abra el software de análisis de hueso y definir una región de interés (ROI) que abarca ambas extremidades traseras de la articulación de la cadera proximalmente a la punta de la pata trasera distalmente. Obtener una imagen utilizando los siguientes parámetros:. 80 kV, 500 mu y 1.300 milisegundos de exposición, 48 micras de tamaño voxel 14,15 </li><li> Calibre la imagen para unidades Hounsfield (UH) dibujando un retorno de la inversión en cada una de las tres cámaras de fantasmas y la introducción de la densidad media en los campos apropiados enEl software. </li><li> Con la herramienta &quot;capturador&quot; en el software, vuelva a orientar la imagen para la tibia de la extremidad posterior izquierda es paralelo a lo largo del eje Z para permitir la vista anatómico más clara para la delimitación de las estructuras óseas corticales ortotópico y HO. </li><li> Comenzando en la rodilla, desplácese distalmente a través de los cortes de imagen hasta que se encuentre HO. Con la herramienta spline manual, hacer un retorno de la inversión alrededor del hueso ectópico en cada 5º rebanada continua distalmente a través de la pata o hasta HO ha sido superado. Utilice la herramienta de extrapolar para ampliar y unir las regiones de interés juntos en un retorno de la inversión que contiene toda la HO. </li><li> Hacer un ROI 3D y elegir el menú de análisis. Calcule el volumen de hueso mediante el establecimiento de los valores inferior y superior de umbral que mejor muestran la ventana de hueso. Utilice los mismos valores de umbral fijados para todos los análisis. </li></ol>

<ol>
	<li>Leblanc, E., 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=BMP-9-induced+muscle+heterotopic+ossification+requires+changes+to+the+skeletal+muscle+microenvironment.">BMP-9-induced muscle heterotopic ossification requires changes to the skeletal muscle microenvironment.</a> J Bone Miner Res. 26 (6), 1166-1177 (2011).</li><li>Shore, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteoinductive+signals+and+heterotopic+ossification.">Osteoinductive signals and heterotopic ossification.</a> J Bone Miner Res. 26 (6), 1163-1165 (2011).</li><li>Wosczyna, M. N., Biswas, A. A., Cogswell, C. A., Goldhamer, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multipotent+progenitors+resident+in+the+skeletal+muscle+interstitium+exhibit+robust+BMP-dependent+osteogenic+activity+and+mediate+heterotopic+ossification.">Multipotent progenitors resident in the skeletal muscle interstitium exhibit robust BMP-dependent osteogenic activity and mediate heterotopic ossification.</a> J Bone Miner Res. 27 (5), 1004-1017 (2012).</li><li>Potter, B. K., 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=Heterotopic+ossification+following+combat-related+trauma.">Heterotopic ossification following combat-related trauma.</a> J Bone Joint Surg Am. 92, 74-89 (2010).</li><li>Van den Bossche, L., Vanderstraeten, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterotopic+ossification:+a+review.">Heterotopic ossification: a review.</a> J Rehabil Med. 37 (3), 129-136 (2005).</li><li>Chakkalakal, S. 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=An+Acvr1+R206H+knock-in+mouse+has+fibrodysplasia+ossificans+progressiva.">An Acvr1 R206H knock-in mouse has fibrodysplasia ossificans progressiva.</a> J Bone Miner Res. 27 (8), 1746-1756 (2012).</li><li>Yu, P. 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=BMP+type+I+receptor+inhibition+reduces+heterotopic+[corrected]+ossification.">BMP type I receptor inhibition reduces heterotopic [corrected] ossification.</a> Nat Med. 14 (12), 1363-1369 (2008).</li><li>Culbert, A. 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=Alk2+regulates+early+chondrogenic+fate+in+fibrodysplasia+ossificans+progressiva+heterotopic+endochondral+ossification.">Alk2 regulates early chondrogenic fate in fibrodysplasia ossificans progressiva heterotopic endochondral ossification.</a> Stem Cells. 32 (5), 1289-1300 (2014).</li><li>Dinther, M., 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=ALK2+R206H+mutation+linked+to+fibrodysplasia+ossificans+progressiva+confers+constitutive+activity+to+the+BMP+type+I+receptor+and+sensitizes+mesenchymal+cells+to+BMP-induced+osteoblast+differentiation+and+bone+formation.">ALK2 R206H mutation linked to fibrodysplasia ossificans progressiva confers constitutive activity to the BMP type I receptor and sensitizes mesenchymal cells to BMP-induced osteoblast differentiation and bone formation.</a> J Bone Miner Res. 25 (6), 1208-1215 (1359).</li><li>Peterson, J. 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=Burn+injury+enhances+bone+formation+in+heterotopic+ossification+model.">Burn injury enhances bone formation in heterotopic ossification model.</a> Ann Surg. 259 (5), 993-998 (2014).</li><li>Scott, M. 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=Brief+review+of+models+of+ectopic+bone+formation.">Brief review of models of ectopic bone formation.</a> Stem Cells Dev. 21 (5), 655-667 (2012).</li><li>Tannous, O., Griffith, C., O'Toole, R. V., Pellegrini, V. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterotopic+ossification+after+extremity+blast+amputation+in+a+Sprague-Dawley+rat+animal+model.">Heterotopic ossification after extremity blast amputation in a Sprague-Dawley rat animal model.</a> J Orthop Trauma. 25 (8), 506-510 (2011).</li><li>Tannous, O., 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=Heterotopic+bone+formation+about+the+hip+undergoes+endochondral+ossification:+a+rabbit+model.">Heterotopic bone formation about the hip undergoes endochondral ossification: a rabbit model.</a> Clin Orthop Relat Res. 471 (5), 1584-1592 (2013).</li><li>Peterson, J. 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=Treatment+of+heterotopic+ossification+through+remote+ATP+hydrolysis.">Treatment of heterotopic ossification through remote ATP hydrolysis.</a> Sci Transl Med. 6 (255), 255ra132 (2014).</li><li>Peterson, J. 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=Early+detection+of+burn+induced+heterotopic+ossification+using+transcutaneous+Raman+spectroscopy.">Early detection of burn induced heterotopic ossification using transcutaneous Raman spectroscopy.</a> Bone. 54 (1), 28-34 (2013).</li><li>Perosky, J. E., 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=Early+detection+of+heterotopic+ossification+using+near-infrared+optical+imaging+reveals+dynamic+turnover+and+progression+of+mineralization+following+Achilles+tenotomy+and+burn+injury.">Early detection of heterotopic ossification using near-infrared optical imaging reveals dynamic turnover and progression of mineralization following Achilles tenotomy and burn injury.</a> J Orthop Res. 32 (11), 1416-1423 (2014).</li><li>Peterson, J. 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=Effects+of+Aging+on+Osteogenic+Response+and+Heterotopic+Ossification+Following+Burn+Injury+in+Mice.">Effects of Aging on Osteogenic Response and Heterotopic Ossification Following Burn Injury in Mice.</a> Stem Cells Dev. , (2014).</li><li>Alfieri, K. A., Forsberg, J. A., Potter, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blast+injuries+and+heterotopic+ossification.">Blast injuries and heterotopic ossification.</a> Bone and Joint Research. 1 (8), 174-179 (2012).</li><li>Hunt, J. L., Arnoldo, B. D., Kowalske, K., Helm, P., Purdue, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterotopic+ossification+revisited:+a+21-year+surgical+experience.">Heterotopic ossification revisited: a 21-year surgical experience.</a> J Burn Care Res. 27 (4), 535-540 (2006).</li><li>Ring, D., Jupiter, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Operative+release+of+ankylosis+of+the+elbow+due+to+heterotopic+ossification.+Surgical+technique.">Operative release of ankylosis of the elbow due to heterotopic ossification. Surgical technique.</a> J Bone Joint Surg Am. 86-A, 2-10 (2004).</li><li>Crane, N. J., Polfer, E., Elster, E. A., Potter, B. K., Forsberg, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Raman+spectroscopic+analysis+of+combat-related+heterotopic+ossification.">Raman spectroscopic analysis of combat-related heterotopic ossification.</a> Bone. 57 (2), 335-342 (2013).</li></ol>

The authors have nothing to disclose

Heterotopic ossification represents a major functional impairment faced by patients that sustain trauma, burns, and invasive musculoskeletal procedures. The most at-risk population are soldiers in modern conflicts with major blast injuries from mechanisms such as improvised explosive devices (IED).18 Improved body armor and forward positioned medical units allows for improved survival of major extremity injury. After initial stabilization and repair of their extremity injury, these patients are at high risk...

Heterotopic ossification (HO) is the formation of ectopic bone in which osteo-potent cells are aberrantly induced to form endochondral bone outside of the skeleton. While the details of the HO formation pathway are still largely unknown, an accepted paradigm includes three key factors: an inflammatory inciting incident, a permissive niche, and mesenchymal stem cells capable of forming bone.1-3 HO is a common comorbidity complicating over 60% of major burn injuries, 65% of combat-related injuries, and 10% of invasive orthopaedic surgery cases.4,5 However, it is often difficult to predict where HO will form because it can occur at sites of local injury or at distant locations that may be otherwise uninjured. This variability in location makes it difficult to intervene prophylactically to prevent reactive bone formation in a locally targeted manner. There are also congenital forms of HO such as fibrodysplasia ossificans progressiva (FOP) in which patients are prone to the development of robust HO in response to minor trauma or inflammatory insult. Powerful animal models using transgenic mice have reproduced this phenotype and provided insight to the molecular pathways that may also be important in trauma induced HO.6-9 Translational research into the pathogenesis of non-congenital HO has used a wide variety of constructs ranging from injury alone to the implantation of exogenous osteo-inductive materials and/or cells.10-13
In our prior work we have validated a simple and reliable model of HO formation in mice which does not require the administration of any exogenous material.14-17 This model created two key conditions to initiate HO: local trauma and global inflammation. This was achieved through the use of an Achilles tenotomy (local trauma) combined with a distant burn injury (global inflammation). Mice received both treatments concurrently and were found to develop a robust amount of HO that could be analyzed by histologic, radiologic, and molecular means. Interestingly, concurrent burn injury significantly increased the amount of HO that formed and accelerated its developmental time-course.14-16 HO developed at predictable sites around the calcaneus, ankle joint, and tibia/fibula of the limb that received the tenotomy. The reliability of HO development at a known location allowed for focused examination of molecular and histologic features in the early stages of ectopic ossification.14,17 To date, 100% of mice (over 50 animals) with a tenotomy and concurrent burn injury have developed HO. Additionally, longitudinal 2D and 3D imaging and spectroscopic analysis were conducted to examine the growth pattern and biochemical make-up of HO.15,16

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>C57BL/6 mice</td>
			<td>Jackson Laboratory</td>
			<td align="right">664</td>
			<td>8-10 weeks old</td>
		</tr>
		<tr>
			<td>Isoflurane &#8211; Fluriso</td>
			<td>VET one, Boise, ID</td>
			<td>V1 501017</td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine &#8211; Buprenex</td>
			<td>Reckitt Benckiser Healthcare</td>
			<td>NDC 12496-0757-1</td>
			<td>0.3 mg/ml solution</td>
		</tr>
		<tr>
			<td>Betadine</td>
			<td>Owens and Minor, Mechanicsville, VA</td>
			<td>2047PVP202</td>
			<td></td>
		</tr>
		<tr>
			<td>5-0 Vicryl sutures</td>
			<td>Ethicon, Summerville, NJ</td>
			<td>J493</td>
			<td></td>
		</tr>
		<tr>
			<td>Tegaderm Film, 6cm x 7cm</td>
			<td>3M</td>
			<td>1624W</td>
			<td>Cut in half to properly cover burn site</td>
		</tr>
		<tr>
			<td>&#181;CT - GE eXplore Locus SP</td>
			<td>GE Healthcare Pre-Clinical Imaging, London, ON, Canada</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microview 2.2 Advanced Bone Analysis Application</td>
			<td>GE Healthcare Pre-Clinical Imaging, London, ON, Canada</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

direct mouse trauma/burn model of heterotopic ossification

Heterotopic ossification (HO) is the formation of bone outside of the skeleton which forms following major trauma, burn injuries, and orthopaedic surgical procedures. The majority of animal models used to study HO rely on the application of exogenous substances, such as bone morphogenetic protein (BMP), exogenous cell constructs, or genetic mutations in BMP signaling. While these models are useful they do not accurately reproduce the inflammatory states that cause the majority of cases of HO. Here we describe a burn/tenotomy model in mice that reliably produces focused HO. This protocol involves creating a 30% total body surface area partial thickness contact burn on the dorsal skin as well as division of the Achilles tendon at its midpoint. Relying solely on traumatic injury to induce HO at a predictable location allows for time-course study of endochondral heterotopic bone formation from intrinsic physiologic processes and environment only. This method could prove instrumental in understanding the inflammatory and osteogenic pathways involved in trauma-induced HO. Furthermore, because HO develops in a predictable location and time-course in this model, it allows for research to improve early imaging strategies and treatment modalities to prevent HO formation.

En el presente estudio, el protocolo se describe para el modelo previamente publicado ratón del trauma / quemadura inducida. HO 14-17 Esto implica la creación de lesiones musculoesqueléticas localizada concurrente con una tenotomía de Aquiles y el insulto inflamatorio global con un espesor parcial quemaduras. Esto da lugar a la formación fiable de hueso reactivo en el sitio de tenotomía que puede ser seguido con imágenes en serie. Hasta la fecha, todos los ratones (más de 50) que han sostenido tanto d...

Watch this Scientific Journal Video about Direct Mouse Trauma/Burn Model of Heterotopic Ossification at JoVE.com

Direct Mouse Trauma/Burn Model of Heterotopic Ossification

An Achilles tenotomy and burn injury model of heterotopic ossification allows for the reliable study of trauma induced ectopic bone formation without the application of exogenous factors.

Ratón directa Trauma / Burn modelo de osificación heterotópica

Heterotopic ossification (HO) is the formation of bone outside of the skeleton which forms following major trauma, burn injuries, and orthopaedic surgical ...

direct-mouse-traumaburn-model-of-heterotopic-ossification

Research

JoVE Journal

Medicine

9.9K vistas.  University of Michigan Medical School. An Achilles tenotomy and burn injury model of heterotopic ossification allows for the reliable study of trauma induced ectopic bone formation without the application of exogenous factors.

Video: Direct Mouse Trauma/Burn Model of Heterotopic Ossification

A Modified Method for Heterotopic Mouse Heart Transplantion

Mice are often used as heart transplant donors and recipients in studies of transplant immunology due to the wide range of transgenic mice and reagents available. A difficulty is presented due to the small size of the animal and the considerable technical challenges of the microsurgery involved in heart transplantation. In particular, a high rate of technical failure early after transplantation may result from recipient death and post-operative complications such as hind limb paralysis or a non-beating heart. Here, the complete technique for heterotopic mouse heart transplantation is demonstrated, involving harvesting the donor heart and its subsequent implantation into a recipient mouse. The donor heart is harvested immediately following in situ perfusion with cold heparinized saline and transection of the ascending aorta and pulmonary artery. The recipient operation involves preparation of the abdominal aorta and inferior vena cava (IVC), followed by end-to-side anastomosis of the donor aorta with the recipient aorta using a single running 10-0 microsuture and a similar anastomosis of the donor pulmonary artery with the recipient IVC. Following the operation the animal is injected with 0.6 ml normal saline subcutaneously and allowed to recover on a 37&#160;&#176;C heating pad. The results from 227 mouse heart transplants are summarized with a success rate at 48 hr of 86.8%. Of the 13.2% failures within 48 hr, 5 (2.2%) experienced hind limb paralysis, 10 (4.4%) had a non-beating heart due to graft ischemic injury and/or thrombosis, while 15 (6.6%) died within 48 hr.

A technique is demonstrated for the microsurgical procedure for heterotopic transplantation of hearts in mice, including simplified methods for donor harvesting and recipient vessel anastomosis.

Un método modificado para heterotópico Ratón Corazón TRASPLANTE

Mice are often used as heart transplant donors and recipients in studies of transplant immunology due to the wide range of transgenic mice and reagents ...

Investigación

Medicina

Heterotopic Mucosal Engrafting Procedure for Direct Drug Delivery to the Brain in Mice

Delivery of therapeutics into the brain is impeded by the presence of the blood-brain barrier (BBB) which restricts the passage of polar and high molecular weight compounds from the bloodstream and into brain tissue. Some direct delivery success in humans has been achieved via implantation of transcranial catheters; however this method is highly invasive and associated with numerous complications. A less invasive alternative would be to dose the brain through a surgically implanted, semipermeable membrane such as the nasal mucosa that is used to repair skull base defects following endoscopic transnasal tumor removal surgery in humans. Drug transfer though this membrane would effectively bypass the BBB and diffuse directly into the brain and cerebrospinal fluid. Inspired by this approach, a surgical approach in mice was developed that uses a donor septal mucosal membrane engrafted over an extracranial surgical BBB defect. This model has been shown to effectively allow the passage of high molecular weight compounds into the brain. Since numerous drug candidates are incapable of crossing the BBB, this model is valuable for performing preclinical testing of novel therapies for neurological and psychiatric diseases.

A mouse model of human endoscopic skull base reconstruction has been developed that creates a semipermeable interface between the brain and nose using nasal mucosal grafts. This method allows researchers to study delivery to the central nervous system of high molecular weight therapeutics which are otherwise excluded by the blood-brain barrier when administered systemically.

Heterotópico mucosas Procedimiento La incorporación del trasplante de Drogas entrega directa al cerebro en ratones

Delivery of therapeutics into the brain is impeded by the presence of the blood-brain barrier (BBB) which restricts the passage of polar and high ...

Murine Heterotopic Heart Transplant Technique

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become proficient in and utilize this technique, it is now widely used by many laboratories around the world. A significant refinement to the original technique was developed and reported in 2001 by Niimi. Described here are the techniques that have evolved over more than a decade in the hands of three surgeons (Plenter, Grazia, Pietra) in our center. These techniques are now being passed on to a younger generation of surgeons and researchers.
Based largely on the Niimi experience, the procedures used have evolved in the fine details - details which we will endeavor to relate here in such a way that others may be able to use this very useful model. Like Niimi, we have found that a video aid to learning is a priceless resource for the beginner.

The manuscript describes the steps required to perform the heterotopic heart transplant in the mouse.

Murino heterotópico Corazón Trasplante Técnica

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become ...

Transplantation of Pulmonary Valve Using a Mouse Model of Heterotopic Heart Transplantation

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed results. However, the cellular and molecular mechanisms of the neotissue development, valve thickening, and stenosis development are not researched extensively. To answer the above questions, we developed a murine heterotopic heart valve transplantation model. A heart valve was harvested from a valve donor mouse and transplanted to a heart donor mouse. The heart with a new valve was transplanted heterotopically to a recipient mouse. The transplanted heart showed its own heartbeat, independent of the recipient&#8217;s heartbeat. The blood flow was quantified using a high frequency ultrasound system with a pulsed wave Doppler. The flow through the implanted pulmonary valve showed forward flow with minimal regurgitation and the peak flow was close to 100 mm/sec. This murine model of heart valve transplantation is highly versatile, so it can be modified and adapted to provide different hemodynamic environments and/or can be used with various transgenic mice to study neotissue development in a tissue engineered heart valve.

In order to understand the cellular and molecular mechanisms underlying neotissue formation and stenosis development in tissue engineered heart valves, a murine model of heterotopic heart valve transplantation was developed. A pulmonary heart valve was transplanted to recipient using the heterotopic heart transplantation technique.

El trasplante de la válvula pulmonar Utilizando un modelo de ratón de heterotópico trasplante cardiaco

Tissue engineered heart valves, especially decellularized valves, are starting to gain momentum in clinical use of reconstructive surgery with mixed ...

Heterotopic Renal Autotransplantation in a Porcine Model: A Step-by-Step Protocol

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality of life when compared to dialysis. Although the last few decades have seen major improvements in patient outcomes following kidney transplantation, the increasing shortage of available organs represents a severe problem worldwide. To expand the donor pool, marginal kidney grafts recovered from extended criteria donors (ECD) or donated after circulatory death (DCD) are now accepted for transplantation. To further improve the postoperative outcome of these marginal grafts, research must focus on new therapeutic approaches such as alternative preservation techniques, immunomodulation, gene transfer, and stem cell administration.
Experimental studies in animal models are the final step before newly developed techniques can be translated into clinical practice. Porcine kidney transplantation is an excellent model of human transplantation and allows investigation of novel approaches. The major advantage of the porcine model is its anatomical and physiological similarity to the human body, which facilitates the rapid translation of new findings to clinical trials. This article offers a surgical step-by-step protocol for an autotransplantation model and highlights key factors to ensure experimental success. Adequate pre- and postoperative housing, attentive anesthesia, and consistent surgical techniques result in favorable postoperative outcomes. Resection of the contralateral native kidney provides the opportunity to assess post-transplant graft function. The placement of venous and urinary catheters and the use of metabolic cages allow further detailed evaluation. For long-term follow-up studies and investigation of alternative graft preservation techniques, autotransplantation models are superior to allotransplantation models, as they avoid the confounding bias posed by rejection and immunosuppressive medication.

Porcine models of organ transplantation provide an important platform to study mechanisms of organ preservation. This article describes a heterotopic porcine renal autotransplantation model, which allows investigating new approaches to improve the outcome of transplantation using marginal kidney grafts.

Heterotópico renal autotrasplante en un modelo porcino: Un Protocolo de Paso a Paso

Kidney transplantation is the treatment of choice for patients suffering from end-stage renal disease. It offers better life expectancy and higher quality ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

Medición de la contractilidad isométrica de la arteria mesentérica de ratón con cable miografía

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Modified Heterotopic Hindlimb Osteomyocutaneous Flap Model in the Rat for Translational Vascularized Composite Allotransplantation Research

Vascularized composite allotransplantation (VCA) is a relatively new field in the reconstructive surgery. Clinical achievements in human VCA include hand and face transplants and, more recently, abdominal wall, uterus, and urogenital transplants. Functional outcomes have exceeded initial expectations, and most recipients enjoy an improved quality of life. However, as clinical experience accumulates, chronic rejection and complications from the immunosuppression must be addressed. In many cases where grafts have failed, the causative pathology has been ischemic vasculopathy. <span style="font-size: 11pt; line-height: 115%; font-family: Arial, sans-serif; color: rgb(41, 43, 49); background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial;">The biological mechanisms of the acute and chronic rejection associated with VCA, especially ischemic vasculopathy, are important areas of research. However, due to the very small number of VCA patients, the evaluation of proposed mechanisms is better addressed in an experimental model. Multiple groups have used animal models to address some of the relevant unsolved questions in VCA rejection and vasculopathy. Several model designs involving a variety of species are described in the literature. Here we present a reproducible model of VCA heterotopic hindlimb osteomyocutaneous flap in the rat that can be utilized for translational VCA research. This model allows for the serial evaluation of the graft, including biopsies and different imaging modalities, while maintaining a low level of morbidity.

Vascularized composite allograft offers life-altering benefits to transplant recipients, but the biological causes of graft rejection and vasculopathy remain poorly understood. The rodent surgical model presented here offers a reproducible, clinically relevant model of transplantation, allowing researchers to evaluate rejection events and potential therapeutic strategies to prevent their occurrence.

Modelo de colgajo Osteomiocucutáneo de extremidades posteriores modificados en la rata para investigación de compuestos alotransplante de compuesto translacional vascularizado

Vascularized composite allotransplantation (VCA) is a relatively new field in the reconstructive surgery. Clinical achievements in human VCA include hand ...

A Mouse Model of Vascularized Heterotopic Spleen Transplantation for Studying Spleen Cell Biology and Transplant Immunity

The spleen is a unique lymphoid organ that plays a critical role in the homeostasis of the immune and hematopoietic systems. Patients that have undergone splenectomy regardless of precipitating causes are prone to develop an overwhelming post-splenectomy infection and experience increased risks of deep venous thrombosis and malignancies. Recently, epidemiological studies indicated that splenectomy might be associated with the occurrence of cardiovascular diseases, suggesting that physiological functions of the spleen have not yet been fully recognized. Here, we introduce a mouse model of vascularized heterotopic spleen transplantation, which not only can be utilized to study the function and behavioral activity of splenic immune cell subsets in different biologic processes, but also can be a powerful tool to test the therapeutic potential of spleen transplantation in certain diseases. The main surgical steps of this model include donor spleen harvest, the removal of recipient native spleen, and spleen graft revascularization. Using congenic mouse strains (e.g., mice with CD45.1/CD45.2 backgrounds), we observed that after syngeneic transplantation, both donor-derived splenic lymphocytes and myeloid cells migrated out of the graft as early as post-operative day 1, concomitant with the influx of multiple types of recipient cells, thus generating a unique chimera. &#160;Despite relatively challenging techniques, this procedure can be performed with &#62;90% success rate. This model allows tracking the fate, longevity, and function of splenocytes during steady state and in a disease setting following a spleen transplantation, thereby offering a great opportunity to discover the distinct role for spleen-derived immune cells in different disease processes.

This protocol details the surgical steps of a mouse model of vascularized heterotopic spleen transplantation, a technically challenging model that can serve as a powerful tool in studying the fate and longevity of spleen cells, the mechanisms of distinct spleen cell populations in disease progression, and transplant immunity.

Un modelo de ratón del trasplante de bazo heterotópico vascularizado para estudiar biología de células del bazo y inmunidad al trasplante

The spleen is a unique lymphoid organ that plays a critical role in the homeostasis of the immune and hematopoietic systems. Patients that have undergone ...

A Simplified Model for Heterotopic Heart Valve Transplantation in Rodents

There is an urgent clinical need for heart valve replacements that can grow in children. Heart valve transplantation is proposed as a new type of transplant with the potential to deliver durable heart valves capable of somatic growth with no requirement for anticoagulation. However, the immunobiology of heart valve transplants remains unexplored, highlighting the need for animal models to study this new type of transplant. Previous rat models for heterotopic aortic valve transplantation into the abdominal aorta have been described, though they are technically challenging and costly. For addressing this challenge, a renal subcapsular transplant model was developed in rodents as a practical and more straightforward method for studying heart valve transplant immunobiology. In this model, a single aortic valve leaflet is harvested and inserted into the renal subcapsular space. The kidney is easily accessible, and the transplanted tissue is securely contained in a subcapsular space that is well vascularized and can accommodate a variety of tissue sizes. Furthermore, because a single rat can provide three donor aortic leaflets and a single kidney can provide multiple sites for transplanted tissue, fewer rats are required for a given study. Here, the transplantation technique is described, providing a significant step forward in studying the transplant immunology of heart valve transplantation.

This protocol describes a simple and efficient method for the transplantation of aortic valve leaflets under the renal capsule to allow for the study of alloreactivity of heart valves.

Un modelo simplificado para el trasplante heterotópico de válvulas cardíacas en roedores

There is an urgent clinical need for heart valve replacements that can grow in children. Heart valve transplantation is proposed as a new type of ...

A Modified Cuff Technique for Mouse Cervical Heterotopic Heart Transplantation Model

Cardiac allograft rejection limits the long-term survival of patients after heart transplantation. A mouse heart transplantation model is ideal for investigating the mechanism of cardiac allograft rejection in preclinical studies because of their high homology with human genes. This understanding would help develop unique approaches to improving patients&#39; long-term survival treated with cardiac allografts. In a mouse model, abdominal donor heart implantation is commonly performed with an end-to-end&#160;anastomosis to the recipient&#39;s aorta and inferior vena cava using stitches. In this model, the donor&#39;s heart is implanted by end-to-end anastomosis to the recipient&#39;s carotid artery and jugular vein by the modified-Cuff technique. The transplantation surgery is performed without stitching and thus may increase the survival of the recipient since there is no interference with the blood supply and venous reflux of the lower body. This mouse model would help investigate the mechanisms underlying the immunological and pathological (acute/chronic) rejection of cardiac allografts.

In the present protocol, a mouse heart transplantation model is used for investigating the mechanism of cardiac allograft rejection. In this heterotopic heart transplantation model, operation efficiency is improved, and the survival of cardiac grafts is ensured by a cervical end-to-end anastomosis of heart implantation using a modified Cuff technique.

Una técnica de manguito modificado para el modelo de trasplante cardíaco heterotópico cervical de ratón

Cardiac allograft rejection limits the long-term survival of patients after heart transplantation. A mouse heart transplantation model is ideal for ...