We would like to acknowledge our funding sources: The California Institute for Regenerative Medicine Clinical Fellow Training Grant (AN), National Science Foundation (MW), Irene Perstein Award (TCM), American College of Surgeons (TCM), American Pediatric Surgical Association (TCM), and the March of Dimes (TCM).

1. Preparation of Injection Pipettes
<ol>
<li>Calibrate the pipette puller such that separation of the glass pipette occurs within 15 seconds (see manufacturer's instructions regarding calibration). The pipette will have a taper where it separates.</li>
<li>Cut the end of the pipette such that the distance from the beginning of the taper to the end of the pipette is 1.04cm to 1.05cm. The length of the pipette is inversely proportional to the caliber of the pipette orifice. Be aware that making a longer pipette also results in a weaker tip that is more susceptible to breakage during the injection.</li>
<li>The next step in making the pipette is to create a smooth bevel by sharpening the tip on a diamond sharpening wheel. At the time of cutting the pipette to the appropriate size, the pipette often breaks with a natural bevel at its tip which must be used when placing the pipette on the wheel. During this process, it is important to gently rest the pipette on the sharpening wheel and periodically re-evaluate to make sure the pipette is still touching the wheel (as the bevel becomes smoother, it will lose contact with the sharpening wheel).</li>
<li>Once the bevel is smooth, the pipette tip must be sharpened (Figure 1). Elevate the pipette such that it is no longer touching the sharpening wheel, rotate it clockwise by 10-50 degrees, and place the pipette back on the rotating sharpening wheel for ~10 seconds. Withdraw the pipette from the sharpening wheel and now examine the edge. This step usually needs to be repeated with several small adjustments to create a sharp edge. If the pipette is placed on its edge for too long, it is more likely to develop an uneven surface (Figure 1). After completing one side, you can proceed to sharpen the opposite edge by repeating the steps above.</li>
<li>Use a permanent marker to draw a circumferential line every 4mm starting where the taper of the pipette begins. These demarcations correspond to 5uL of volume.</li>
</ol>
2. in Utero Transplantation
<ol>
<li>After preparing the injectable material (e.g. cells, virus, etc.) you can set up for the injection. We use a microinjector connected to compressed air with the following settings: (Pressure settings: input 60-80 psi, fill 40 psi, inject 8-12 psi, balance 0 psi, hold 0 psi; Injection time 100 milliseconds).</li>
<li>To sterilize the injection pipette, clean it twice with 70% EtOH followed by twice with sterile 1X PBS. As the tip of the pipette is very fragile, we do not recommend autoclaving the injection pipettes.</li>
<li>Injections can either be done using 2.5X-3.5X magnification loupes or a dissecting microscope. Prepare your procedure area with a warming blanket, lighting, and necessary surgical instruments.</li>
<li>Anesthetize the pregnant mouse (we utilize isoflurane and oxygen delivered via a continuous flow anesthesia unit). Place the mouse on a heating pad in the supine position and affix each limb with tape to secure the mouse in place.</li>
<li>Clip the fur. Then, wearing sterile surgical gloves, prep the abdomen with 10% povidone-iodine followed by alcohol, and inject an analgesic such as buprenorphine.</li>
<li>Make a 1cm incision in the lower abdomen (the most inferior aspect of the incision should be approximately 1cm superior to the introitus). Incise the skin and the fascia. Be careful not to injure the abdominal organs (intestines and bladder) which are immediately under the thin layer of fascia.</li>
<li>Using cotton swabs, gently stretch the fascia and deliver the gravid uterus through the incision. Count the total number of fetuses by first identifying the right and left ovaries to make sure you visualize the entire uterus. Place the uterus back in the abdominal cavity before you proceed so that the fetuses remain warm while you prepare for the injections.</li>
<li>Draw up the appropriate volume of material for the number of fetuses you plan to inject. While filling the needle with your sample, it is important to keep the pipette tip submersed to avoid aspirating your sample into the microinjector tubing. Since cells are generally in a small volume, we usually place them in a small microfuge (ex: 0.5mL) tube or directly on a piece of Parafilm to be able to fill the needle without breaking the pipette tip.</li>
<li>Gently hold each fetus and identify the part of the fetus you plan to inject (e.g. liver, peritoneal cavity, leg, etc). With your thumb and forefinger, you must stabilize the fetus within the amniotic cavity so that it does not rotate while you are performing the injection. It is important to hold the fetus firmly enough to stabilize it yet gently enough to avoid damaging it.</li>
<li>Carefully insert the pipette through the uterus, amnion, and fetal skin, and into the target organ. If the pipette is sharp, it should pass easily through these tissues. If the pipette tip is dull, you will notice tenting of the uterus and amniotic membranes. Inject the desired volume into each fetus. It is imperative that your movements be steady during the time of the insertion, injection, and withdrawal of the pipette.</li>
<li>Once the desired volume is injected, withdraw the pipette carefully. If done properly, material should not leak out from the amniotic cavity or uterus. If a large hole is created in the amnion, which one can recognize by leakage of amniotic fluid, then survival is jeopardized. Finally, for studies that involve postnatal harvesting, all fetuses must receive technically perfect injections since there is no way to discern injected and uninjected fetuses after birth.</li>
<li>If you are performing injections into the fetal liver, you may occasionally see blood in the pipette tip after it is withdrawn- this confirms you are in the correct position and should not affect survival. If performing intra-peritoneal injections, aim slightly below the fetal liver. For intramuscular injections, you may position the fetus to identify the hip and femur and inject the gluteus muscle. Finally, for intraventricular injections, it is easy to see the coronal sutures to direct the pipette to the appropriate target. For these injections, slightly larger caliber pipettes are required to penetrate the skull without breaking the pipette.</li>
<li>Next, carefully place the uterus back into the abdominal cavity. Make sure it is not twisted on itself or around its vascular supply. Deliver 1mL of sterile 1X PBS in the mother's peritoneal cavity to replace any fluid that was lost during the procedure. Close the incision in 2 layers with a 5-0 braided absorbable suture (ex: Vicryl). First close the fascia without injuring the underlying bowel or bladder, and then close the skin.</li>
<li>At this time, post-procedure medications can be administered for analgesia. Return each injected female to its own individual cage and place the cage on a warming blanket. Monitor the mouse until it is upright. Put bedding in the cage and place the mouse in a quiet area of the mouse facility where it should not be disturbed (i.e. no cage cleaning) until several days after delivery. Minimizing any additional stress for the animal will decrease the chances of preterm labor. </li> 
<li>Once you have completed the injections, clean your pipette twice with sterile 1X PBS and once with 70% EtOH.</li>
<li>Injected females should be observed daily to insure they are recovering from the procedure without difficulty. The incision should be monitored for swelling, inflammation, wound separation, and other signs of infection. Post-operative analgesics can be administered as needed.</li>
</ol>
3. Representative Results:
Survival of the injected fetuses to term delivery is the main limiting factor to achieving success with this technique. Depending on the material injected and the strain of mouse being used, survival rates can vary. In general, injections of hematopoietic cells into wild-type mice at E14 should result in at least 50% live-born pups. Higher rates of survival are possible depending on both the technical aspects of the injection as well as the characteristics of the mice being injected.
Minimizing trauma to the uterus and amniotic membranes is the most important technical aspect of this protocol. Sharp, small caliber pipettes will result in minimal uterine trauma during the injection. We do not recommend using standard injection needles as the caliber of pre-fabricated needles is too large and would result in a large hole in the uterus. Hand crafted glass injection pipettes are the only small caliber needles that can be utilized for in utero injections. Careful and meticulous surgical technique, including gentle handling of the uterus and a short anesthetic is also crucial for optimal results.
Specific characteristics of the recipient mice such as the genetic background, gestational age, and litter size can also affect survival. Certain strains of mice are more susceptible to preterm labor and pregnancy loss depending on their genetic background.15 Transgenic animals with muscular or neurodegenerative defects can have an impaired ability to deliver fetuses vaginally after undergoing a midline laparotomy.8 These pregnant females may require delivery by cesarean section. We have also found that the gestational age at the time of injection can impact viability. Fetuses that are younger than embryonic day 12 have lower rates of survival than older fetuses. Finally, we have found that large litter sizes (>10 fetuses) tend to have higher rates of fetal demise after injection. Attention to both the technical aspects of this technique and the specific characteristics of the mice being injected can maximize survival of the injected fetuses.
When these methods are performed correctly, one can expect that all fetuses are exposed to the injected material. Similar to the postnatal setting, however, the successful delivery of cells or viruses in utero does not always result in donor cell engraftment or gene expression, respectively. The engraftment of stem cells, for example, is dependent on several factors such as the dose and source of the transplanted cells. Similarly, the success of viral transduction is, in part, determined by the type of viral vector used. One must understand the numerous factors that impact pup survival, cellular engraftment, and viral transduction to achieve success with this protocol.

<img src="/files/ftp_upload/2303/2303fig1.jpg" alt="Figure 1" /> 
Figure 1. Diagram depicting proper sharpening of the injection pipettes (Step 1.4)

<ol>
	<li>Flake, A. W. <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+X-linked+severe+combined+immunodeficiency+by+in+utero+transplantation+of+paternal+bone+marrow.">Treatment of X-linked severe combined immunodeficiency by in utero transplantation of paternal bone marrow.</a> N Engl J Med. 335, 1806-1810 (1996).</li><li>Wengler, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-utero+transplantation+of+parental+CD34+haematopoietic+progenitor+cells+in+a+patient+with+X-linked+severe+combined+immunodeficiency+(SCIDXI).">In-utero transplantation of parental CD34 haematopoietic progenitor cells in a patient with X-linked severe combined immunodeficiency (SCIDXI).</a> Lancet. 348, 1484-1487 (1996).</li><li>Flake, A. W., Zanjani, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=in+utero+hematopoietic+stem+cell+transplantation:+ontogenic+opportunities+and+biologic+barriers.">in utero hematopoietic stem cell transplantation: ontogenic opportunities and biologic barriers.</a> Blood. 94, 2179-2191 (1999).</li><li>Merianos, 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=Maternal+alloantibodies+induce+a+postnatal+immune+response+that+limits+engraftment+following+in+utero+hematopoietic+cell+transplantation+in+mice.">Maternal alloantibodies induce a postnatal immune response that limits engraftment following in utero hematopoietic cell transplantation in mice.</a> J Clin Invest. 119, 2590-2600 (2009).</li><li>Peranteau, W. H., Endo, M., Adibe, O. O., Flake, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence+for+an+immune+barrier+after+in+utero+hematopoietic-cell+transplantation.">Evidence for an immune barrier after in utero hematopoietic-cell transplantation.</a> Blood. 109, 1331-1333 (2007).</li><li>Kim, H. B., Shaaban, A. F., Yang, E. Y., Liechty, K. W., Flake, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microchimerism+and+tolerance+after+in+utero+bone+marrow+transplantation+in+mice.">Microchimerism and tolerance after in utero bone marrow transplantation in mice.</a> J Surg Res. 77, 1-5 (1998).</li><li>Durkin, E. T., Jones, K. A., Rajesh, D., Shaaban, 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=Early+chimerism+threshold+predicts+sustained+engraftment+and+NK-cell+tolerance+in+prenatal+allogeneic+chimeras.">Early chimerism threshold predicts sustained engraftment and NK-cell tolerance in prenatal allogeneic chimeras.</a> Blood. 112, 5245-5253 (2008).</li><li>Mackenzie, T. C., Shaaban, A. F., Radu, A., Flake, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engraftment+of+bone+marrow+and+fetal+liver+cells+after+in+utero+transplantation+in+MDX+mice.">Engraftment of bone marrow and fetal liver cells after in utero transplantation in MDX mice.</a> J Pediatr Surg. 37, 1058-1064 (2002).</li><li>Hayashi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mixed+chimerism+following+in+utero+hematopoietic+stem+cell+transplantation+in+murine+models+of+hemoglobinopathy.">Mixed chimerism following in utero hematopoietic stem cell transplantation in murine models of hemoglobinopathy.</a> Exp Hematol. 31, 176-184 (2003).</li><li>Bouchard, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+transgene+expression+in+cardiac+and+skeletal+muscle+following+fetal+administration+of+adenoviral+or+adeno-associated+viral+vectors+in+mice.">Long-term transgene expression in cardiac and skeletal muscle following fetal administration of adenoviral or adeno-associated viral vectors in mice.</a> J Gene Med. 5, 941-950 (2003).</li><li>Meza, N. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rescue+of+pyruvate+kinase+deficiency+in+mice+by+gene+therapy+using+the+human+isoenzyme.">Rescue of pyruvate kinase deficiency in mice by gene therapy using the human isoenzyme.</a> Mol Ther. 17, 2000-2009 (2009).</li><li>MacKenzie, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+transduction+of+liver+and+muscle+after+in+utero+injection+of+lentiviral+vectors+with+different+pseudotypes.">Efficient transduction of liver and muscle after in utero injection of lentiviral vectors with different pseudotypes.</a> Mol Ther. 6, 349-358 (2002).</li><li>MacKenzie, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transduction+of+satellite+cells+after+prenatal+intramuscular+administration+of+lentiviral+vectors.">Transduction of satellite cells after prenatal intramuscular administration of lentiviral vectors.</a> J Gene Med. 7, 50-58 (2005).</li><li>Sabatino, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Persistent+expression+of+hF.IX+After+tolerance+induction+by+in+utero+or+neonatal+administration+of+AAV-1-F.IX+in+hemophilia+B+mice.">Persistent expression of hF.IX After tolerance induction by in utero or neonatal administration of AAV-1-F.IX in hemophilia B mice.</a> Mol Ther. 15, 1677-1685 (2007).</li><li>Mellor, A. L., Munn, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunology+at+the+maternal-fetal+interface:+lessons+for+T+cell+tolerance+and+suppression.">Immunology at the maternal-fetal interface: lessons for T cell tolerance and suppression.</a> Annu Rev Immunol. 18, 367-391 (2000).</li><li>Billingham, R. E., Brent, L., Medawar, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Actively+acquired+tolerance+of+foreign+cells.">Actively acquired tolerance of foreign cells.</a> Nature. 172, 603-606 (1953).</li><li>Endo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+transfer+to+ocular+stem+cells+by+early+gestational+intraamniotic+injection+of+lentiviral+vector.">Gene transfer to ocular stem cells by early gestational intraamniotic injection of lentiviral vector.</a> Mol Ther. 15, 579-587 (2007).</li><li>Waddington, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+transgene+expression+by+administration+of+a+lentivirus-based+vector+to+the+fetal+circulation+of+immuno-competent+mice.">Long-term transgene expression by administration of a lentivirus-based vector to the fetal circulation of immuno-competent mice.</a> Gene Ther. 10, 1234-1240 (2003).</li><li>Schachtner, S., Buck, C., Bergelson, J., Baldwin, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporally+regulated+expression+patterns+following+in+utero+adenovirus-mediated+gene+transfer.">Temporally regulated expression patterns following in utero adenovirus-mediated gene transfer.</a> Gene Ther. 6, 1249-1257 (1999).</li></ol>

No conflicts of interest declared.

Over 50 years ago, Billingham, Brent, and Medawar used in utero transplantation in mice to induce immune tolerance to foreign proteins.16 Since that time, several variations of this technique have been used to address questions in immunology and stem cell biology.
The protocol detailed here is one of the most accessible methods for IUT. The fetal liver offers an easily visualized target and provides access to the systemic circulation via the portal and hepatic veins. Ho...

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		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Pipettes</td>
<td>&nbsp;</td>
<td>Kimble</td>
<td>71900-100</td>
<td>&nbsp;</td>
<tr>
<td>Pipette puller</td>
<td>&nbsp;</td>
<td>Sutter Instruments Company</td>
<td>Model P-30</td>
<td>&nbsp;</td>
<tr>
<td>Microinjector</td>
<td>&nbsp;</td>
<td>Narishige</td>
<td>IM-300</td>
<td>&nbsp;</td>
<tr>
<td>Pipette sharpener</td>
<td>&nbsp;</td>
<td>Sutter Instruments Company</td>
<td>Model BV-10</td>
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a mouse model of in utero transplantation

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus. For example, in utero transplantation (IUT) of hematopoietic stem cells has been used to successfully treat patients with severe combined immunodeficiency.1,2 In several other conditions, however, IUT has been attempted without success.3 Given these mixed results, the availability of an efficient non-human model to study the biological sequelae of stem cell transplantation and gene therapy is critical to advance this field. We and others have used the mouse model of IUT to study factors affecting successful engraftment of in utero transplanted hematopoietic stem cells in both wild-type mice4-7 and those with genetic diseases.8,9 The fetal environment also offers considerable advantages for the success of in utero gene therapy. For example, the delivery of adenoviral10, adeno-associated viral10, retroviral11, and lentiviral vectors12,13 into the fetus has resulted in the transduction of multiple organs distant from the site of injection with long-term gene expression. in utero gene therapy may therefore be considered as a possible treatment strategy for single gene disorders such as muscular dystrophy or cystic fibrosis. Another potential advantage of IUT is the ability to induce immune tolerance to a specific antigen. As seen in mice with hemophilia, the introduction of Factor IX early in development results in tolerance to this protein.14 
In addition to its use in investigating potential human therapies, the mouse model of IUT can be a powerful tool to study basic questions in developmental and stem cell biology. For example, one can deliver various small molecules to induce or inhibit specific gene expression at defined gestational stages and manipulate developmental pathways. The impact of these alterations can be assessed at various timepoints after the initial transplantation. Furthermore, one can transplant pluripotent or lineage specific progenitor cells into the fetal environment to study stem cell differentiation in a non-irradiated and unperturbed host environment.
The mouse model of IUT has already provided numerous insights within the fields of immunology, and developmental and stem cell biology. In this video-based protocol, we describe a step-by-step approach to performing IUT in mouse fetuses and outline the critical steps and potential pitfalls of this technique.

Watch this Scientific Journal Video about A Mouse Model of in Utero Transplantation at JoVE.com

A Mouse Model of in Utero Transplantation

The mouse model of in utero transplantation is a versatile tool that can be used to study the potential clinical applications of stem cell transplantation and gene therapy in the fetus. In this protocol, we present a general approach to performing this technique

A Mouse Model of in Utero Transplantation

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus.  For example, in ...

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JoVE Journal

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19.3K vistas.  University of California. El modelo de ratón de En el útero El trasplante es una herramienta versátil que puede usarse para estudiar las posibles aplicaciones clínicas de trasplante de células madre y terapia génica en el feto. En este protocolo, se presenta un enfoque general a la realización de esta técnica

Video: A Mouse Model of in Utero Transplantation

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.

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

Murine Corneal Transplantation: A Model to Study the Most Common Form of Solid Organ Transplantation

Corneal transplantation is the most common form of organ transplantation in the United States with between 45,000 and 55,000 procedures performed each year. While several animal models exist for this procedure and mice are the species that is most commonly used. The reasons for using mice are the relative cost of using this species, the existence of many genetically defined strains that allow for the study of immune responses, and the existence of an extensive array of reagents that can be used to further define responses in this species. This model has been used to define factors in the cornea that are responsible for the relative immune privilege status of this tissue that enables corneal allografts to survive acute rejection in the absence of immunosuppressive therapy. It has also been used to define those factors that are most important in rejection of such allografts. Consequently, much of what we know concerning mechanisms of both corneal allograft acceptance and rejection are due to studies using a murine model of corneal transplantation. In addition to describing a model for acute corneal allograft rejection, we also present for the first time a model of late-term corneal allograft rejection.

Mice have been used as a model for studying many forms of transplantation, including corneal transplantation. We describe in this report a murine model for both acute and late-term corneal transplantation.

Corneal transplantation is the most common form of organ transplantation in the United States with between 45,000 and 55,000 procedures performed each ...

Transplantation Into the Mouse Ovarian Fat Pad

Orthotopic transplantation assays in mice are invaluable for studies of cell regeneration and neoplastic transformation. Common approaches for orthotopic transplantation of ovarian surface and tubal epithelia include intraperitoneal and intrabursal administration of cells. The respective limitations of these methods include poorly defined location of injected cells and limited space volume. Furthermore, they are poorly suited for long-term structural preservation of transplanted organs. To address these challenges, we have developed an alternative approach, which is based on the introduction of cells and tissue fragments into the mouse fat pad. The mouse ovarian fat pad is located in the immediate vicinity of the ovary and uterine tube (aka oviduct, fallopian tube), and provides a familiar microenvironment for cells and tissues of these organs. In our approach fluorescence-labeled mouse and human cells, and fragments of the uterine tube are engrafted by using minimally traumatic dorsal incision surgery. Transplanted cells and their outgrowths are easily located in the ovarian fat pad for over 40 days. Long-term transplantation of the entire uterine tube allows correct preservation of all principle tissue components, and does not result in adverse side effects, such as fibrosis and inflammation. Our approach should be uniquely applicable for answering important biological questions such as differentiation, regenerative and neoplastic potential of specific cell populations. Furthermore, it should be suitable for studies of microenvironmental factors in normal development and cancer.

We describe an ovarian fad pad transplantation assay suitable for studies of normal and transformed epithelia of the female reproductive tract. The mouse fat pad allows transplantation of large tissue fragments, is easily accessible for surgery and imaging, and provides the most favorable native environment for tissues of M&#252;llerian origin.

Orthotopic transplantation assays in mice are invaluable for studies of cell regeneration and neoplastic transformation. Common approaches for orthotopic ...

Using the Sleeve Technique in a Mouse Model of Aortic Transplantation - An Instructional Video

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the aorta in mice using the sleeve method was short and easy averaging 20 min, permitting studies of iso/allo grafts. The following article describes the aortic transplantation procedure used in our laboratory. The mice were anesthetized with a mixture of 1.5% volume isoflurane and 100% oxygen through a face mask. At this point, the segment of the aorta between the renal arteries and its bifurcation was separated from the vena cava, freely prepared and clampedat the proximal and distal segments with a single silk suture. Prior to the removal of the aorta, a saline solution containing heparin was injected into the inferior vena cava. Then the aorta was cut between the clamps and a saline heparin solution was used to flush the lumen. The sleeve technique with monofilament sutures was used in order to transplant the abdominal aorta in the orthotopic position.

We present an orthotopic aortic transplantation model using the sleeve technique in mice. It is a very rapid anastomosis method, which can be employed in studies of vascular disease.

Orthotopic aortic transplantation using the sleeve technique reduces injury to the aorta with failure rate of only 10-20%. The time to anastomose the ...

Mouse Model for Pancreas Transplantation Using a Modified Cuff Technique

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the availability of the widest range of molecular probes and reagents to perform in vivo as well as in vitro studies. Based on our experience with various murine transplantation models, we developed a heterotopic pancreas transplantation model in mice with the intent to analyze mechanisms underlying severe ischemia reperfusion injury-associated early graft damage. In contrast to previously described techniques using suture techniques, herein we describe a new procedure using a non-suture cuff technique. 
In recent years, we have performed more than 300 pancreas transplantations in mice with an overall success rate of &gt;90%, a success rate never described before in mouse pancreas transplantation. The backbone of this non-suture cuff technique for graft revascularization consists of two major steps: (I) pulling the recipient vessel over a polyethylene/polyamide cuff and fixing it with a circumferential ligature, and (II) placing the donor vessel over the everted recipient vessel and fixing it with a second circumferential ligature. The resultant continuity of the endothelial layer results in less thrombogenic lesions with high patency rates and, finally, high success rates.
In this model, arterial anastomosis is achieved by pulling the abdominal aorta of the donor graft over the everted common carotid artery of the recipient animal. Venous drainage of the graft is achieved by pulling the portal vein of the graft over the everted external jugular vein of the recipient. This manuscript provides details and crucial steps of the organ recovery and organ implantation procedures, which will allow researchers with microsurgical skills to perform the transplantation successfully in their laboratories.

Among abdominal solid organ transplantation, pancreatic grafts are prone to develop severe ischemia reperfusion injury-associated graft damage, leading eventually to early graft loss. This protocol describes a model of murine pancreas transplantation using a non-suture cuff technique, ideally suited for analyzing these early, deleterious damages.

Mouse models have several advantages in transplantation research, including easy handling, a variety of genetically well-defined strains, and the ...

Intravital Microscopy and Thrombus Induction in the Earlobe of a Hairless Mouse

Thrombotic complications of vascular diseases are one leading cause of morbidity and mortality in industrial nations. Due to the complex interactions between cellular and non-cellular blood components during thrombus formation, reliable studies of the physiology and pathophysiology of thrombosis can only be performed in vivo. Therefore, this article presents an ear model in hairless mice and focuses on the in vivo analysis of microcirculation, thrombus formation, and thrombus evolution. By using intravital fluorescence microscopy and the intravenous (iv) application of the respective fluorescent dyes, a repetitive analysis of microcirculation in the auricle can easily be performed, without the need for surgical preparation. Furthermore, this model can be adapted for in vivo studies of different issues, including wound healing, reperfusion injury, or angiogenesis. In summary, the ear of hairless mice is an ideal model for the in vivo study of skin microcirculation in physiological or pathophysiological conditions and for the evaluation of its reaction to different systemic or topical treatments.

The ear model of the hairless SKH1-Hrhr mouse enables intravital fluorescence microscopy of microcirculation and phototoxic thrombus induction without prior surgical preparation in the examined microvascular bed. Therefore, the ear of the hairless mouse is an excellent in vivo model to study the complex interactions during microvascular thrombus formation, thrombus evolution, and thrombolysis.

Thrombotic complications of vascular diseases are one leading cause of morbidity and mortality in industrial nations. Due to the complex interactions ...

Cardiopulmonary Bypass in a Mouse Model: A Novel Approach

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization and for minimizing organ damage resulting from prolonged extracorporal circulation. The goal of this paper was to demonstrate a fully functional and clinically relevant model of cardiopulmonary bypass in a mouse. We report on the device design, perfusion circuit optimization, and microsurgical techniques. This model is an acute model, which is not compatible with survival due to the need for multiple blood drawings. Because of the range of tools available for mice (e.g., markers, knockouts, etc.), this model will facilitate investigation into the molecular mechanisms of organ damage and the effect of cardiopulmonary bypass in relation to other comorbidities.

This paper describes how to perform cardiopulmonary bypass in mice. This novel model will facilitate the investigation of the molecular mechanisms involved in organ damage.

As prolonged cardiopulmonary bypass becomes more essential during cardiac interventions, an increasing clinical demand arises for procedure optimization ...

Intraportal Transplantation of Pancreatic Islets in Mouse Model

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation site in experimental islet transplantation is the kidney capsule. However, as less is known about the interaction of pancreatic islets with blood constituents, it also makes sense to utilize the portal vein approach in experimental islet transplantation.
This protocol demonstrates an intraportal islet transplantation technique in NMRI nude mice. Streptozotocin (180 mg/kg) is injected intraperitoneally to induce hyperglycemia in recipient mice. They are considered as diabetic at a non-fasting blood glucose level greater than 20 mmol/L. One day prior to transplantation, mouse pancreatic islets are isolated from the donor pancreas by collagenase digestion; a minimum of 350 islets are utilized per diabetic recipient. Depending upon the islet isolation yield, two or more donor mice are utilized per recipient. After overnight culture at 37 &#176;C, islets are administered into the recipient liver via the portal vein. After surgery, the mice are protected in red Makrolon houses and observed until are awake. This protocol maintains glycemic control for 120 days in syngeneic mice and 15 days in allogeneic mice.

Pancreatic islet transplantation is a way to achieve normoglycemia in type 1 diabetes. This article focuses on the transplantation technique through the intraportal route to maintain normal glucose levels in diabetic mice.

Pancreatic islet transplantation to reduce hyperglycemia is highly successful in rodents with chemically-induced diabetes. The most common transplantation ...

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.

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

Veno-Venous Extracorporeal Membrane Oxygenation in a Mouse

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for acute as well as end-stage lung diseases. With the increase in clinical demand and prolonged use of ECMO, procedural optimization and prevention of multi-organ damage are of critical importance. The aim of this protocol is to present a detailed technique of veno-venous ECMO in a non-intubated, spontaneously breathing mouse. This protocol demonstrates the technical design of the ECMO and surgical steps. This murine ECMO model will facilitate the study of pathophysiology related to ECMO (e.g., inflammation,bleeding and thromboembolic events). Due to the abundance of genetically modified mice, the molecular mechanisms involved in ECMO-related complications can also be dissected.

Here we present a protocol describing the technique of veno-venous extracorporeal membrane oxygenation (ECMO) in a non-intubated, spontaneously breathing mouse. This murine model of ECMO can be effectively implemented in experimental studies of acute and end-stage lung diseases.

The use of extracorporeal membrane oxygenation (ECMO) has increased substantially in recent years. ECMO has become a reliable and effective therapy for ...