The authors have no acknowledgments.

All animal procedures were performed with the approval of the Institutional Animal Care and Use Committee of the University of Cincinnati and in accordance with the Guide for the Care and Use of Laboratory Animals from the National Institutes of Health (NIH Publication No. 85-23, Revised 1996).
1. Preparing the Mouse
<ol>
	<li>Euthanize by exposing the animal to a supratherapeutic dose of anesthetic, isoflurane inhaled to effect. Verify primary euthanasia via toe pinch as a noxious stimulus. Secondary method of euthanasia, diaphragm cutting, will occur in an upcoming step. Alternative methods may be used granted euthanasia is obtained.</li>
	<li>Sanitizie the external surface of the mouse by spraying the fur along the abdominal region, where the initial cuts will be made, with 70% ethanol to the point of moisture so that the fur is wet with ethanol and any loose/dry hairs do not enter the region.</li>
	<li>Lay the mouse out on a surgical board in the supine position with upper and lower appendages extended outward.</li>
	<li>Secure appendages to the board using surgical tape.</li>
</ol>
2. Isolation of the Heart and Aorta
<ol>
	<li>After proper positioning of the mouse, use forceps to locate and isolate abdominal skin just inferior to the xiphoid process of the sternum.</li>
	<li>Create tension by lifting the skin straight up and use scissors to remove the superficial skin, exposing the superior portion of the peritoneum and inferior portion of the thoracic cavity.</li>
	<li>Enter the peritoneal cavity by lifting the xiphoid process and making lateral incisions just inferior to the process along the subcostal margins.</li>
	<li>Dissect up into the thoracic cavity, going through the diaphragm, being sure not to lacerate the heart or any major blood vessels.</li>
	<li>Extend the lateral incisions made in step 2.3 cranially to remove the anterior portion of the ribcage. If necessary, free the heart from the anterior chest wall using blunt dissection.</li>
	<li>Clean the chest cavity of extraneous blood and fluid by using sterile gauze to absorb material. Once the area is more visible, remove the lungs to better expose the heart and aorta.</li>
</ol>
3. Perfusion of Heart and Aorta
NOTE: To obtain blood via cardiac puncture, do so just prior to this step.
<ol>
	<li>Fill a 10 cc syringe with 10 ml of sterile ice cold 1x phosphate buffer solution (PBS), and attach a 25 gauge needle to the syringe.</li>
	<li>Gently insert the needle into the left ventricle of the heart.</li>
	<li>Cut the right atrium to alleviate pressure buildup from perfusion. Perfuse the contents of the syringe into the mouse over 2 - 3 min.</li>
	<li>Use sterile gauze at the opening in the right atrium to absorb perfusion fluid.</li>
</ol>
4. Isolation and Excision of the Aorta
<ol>
	<li>Upon completion of perfusion, use sterile gauze to absorb any remaining fluid clouding the field of view within the thoracic cavity.</li>
	<li>Expose the gastrointestinal contents by cutting caudally through the abdominal wall, extending the incision to the suprapubic area. Extend the incision further towards the lower limbs bilaterally to create skin flaps which can be pinned down or excised.</li>
	<li>Remove the lobes of the liver, pancreas, stomach, spleen, and intestines to better visualize the aorta. Take care when dissecting near the perirenal region, as the aorta is superficial at the branches of the renal arteries. 
	NOTE: Perform this step in a precise and matriculate manner as the gastrointestinal tract is rich with bacteria which increases the propensity for contamination.</li>
	<li>Rinse the area with 1x PBS and remove all fluid by absorption with a sterile gauze.</li>
	<li>Using sterile microscissors and microforceps, separate the aorta from the spine dorsally and the esophagus ventrally. It is best to use blunt dissection and utilizing a dissection microscope for this. 
	NOTE: In isolating the aorta, start caudally at the iliac bifurcation and move cranially cleaning and separating the aorta from the dorsal surface of the cavity or start cranially at the carotids and brachiocephalic arteries dissecting caudally. Either method is appropriate and is up to the researchers comfort.</li>
	<li>Remove the perivascular adipose tissue using fine microscissors being sure not to remove a portion of the aortic wall. This is essential to minimize the potential for fibroblast contamination when culturing aortic smooth muscle cells.</li>
</ol>

<ol>
	<li>Go, A. 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=Heart+disease+and+stroke+statistics--2014+update:+a+report+from+the+American+Heart+Association.">Heart disease and stroke statistics--2014 update: a report from the American Heart Association.</a> Circulation. 129 (3), 28-292 (2014).</li><li>Ross, R., Harker, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyperlipidemia+and+atherosclerosis.">Hyperlipidemia and atherosclerosis.</a> Science. 193 (4258), 1094-1100 (1976).</li><li>Clouse, W. 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=Acute+aortic+dissection:+population-based+incidence+compared+with+degenerative+aortic+aneurysm+rupture.">Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture.</a> Mayo Clin Proc. 79 (2), 176-180 (2004).</li><li>Daugherty, A., Cassis, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+abdominal+aortic+aneurysms.">Mouse models of abdominal aortic aneurysms.</a> Arterioscler Thromb Vasc Biol. 24 (3), 429-434 (2004).</li><li>Pleumeekers, H. J., 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=Aneurysms+of+the+abdominal+aorta+in+older+adults.+The+Rotterdam+Study.">Aneurysms of the abdominal aorta in older adults. The Rotterdam Study.</a> Am J Epidemiol. 142 (12), 1291-1299 (1995).</li><li>Brophy, C. M., Reilly, J. M., Smit, G. J., Tilson, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+inflammation+in+nonspecific+abdominal+aortic+aneurysm+disease.">The role of inflammation in nonspecific abdominal aortic aneurysm disease.</a> Ann Vasc Surg. 5 (3), 229-233 (1991).</li><li>Ray, J. L., Leach, R., Herbert, J. M., Benson, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+vascular+smooth+muscle+cells+from+a+single+murine+aorta.">Isolation of vascular smooth muscle cells from a single murine aorta.</a> Methods Cell Sci. 23 (4), 185-188 (2001).</li><li>Weiss, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+the+murine+cardiovascular+system+with+magnetic+resonance.">Imaging the murine cardiovascular system with magnetic resonance.</a> Circ Res. 88 (6), 550-551 (2001).</li><li>Graham, E. L., Balla, C., Franchino, H., Melman, Y., del Monte, F., Das, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+culture,+and+functional+characterization+of+adult+mouse+cardiomyoctyes.">Isolation culture, and functional characterization of adult mouse cardiomyoctyes.</a> J Vis Exp. (79), 50289 (2013).</li><li>Wassef, M., Upchurch, G. R., Kuivaniemi, H., Thompson, R. W., Tilson, M. D. 3. r. d. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Challenges+and+opportunities+in+abdominal+aortic+aneurysm+research.">Challenges and opportunities in abdominal aortic aneurysm research.</a> J Vasc Surg. 45 (1), 192-198 (2007).</li></ol>

The authors have nothing to disclose.

Aortic disease can lead to significant systemic pathology and possibly death in severe cases. Treatment options are currently limited therefore continued research in the field is necessary10. Murine models are ideal to further study disease progression and potentially therapeutic options4. Therefore, the successful completion of the method described in this manuscript will provide investigators with the tools to measure disease progression and drug efficacy. 
This technique can be modified in several ways in order to optimize the results. The use of surgical loupes or a dissecting microscope can aid in the visualization of the murine anatomy and vasculature details and when removing surrounding adipose tissue from the aorta. Additionally, the use of dedicated surgical utensils for specific tasks can increase the longevity of tools; for example, the use of scissors for cutting skin and separate scissors to cut through the ribs would be ideal. The use of a small gauged needle when perfusing the heart is preferred as this will allow the tissue to close around the puncture as opposed to a larger gauge needle where a hole will remain. 
After the aorta is successfully removed, it can be utilized for a variety of assays. The aorta can be used for molecular studies such as enzyme activity, protein expression and gene expression profiles. Additionally, the aorta can be fixed for histologic analysis where in situ assays can be utilized as well as characterization of the aortic morphology. Finally, one can isolate smooth muscle and/or endothelial cells from a freshly harvest aorta for in vitro studies with these primary isolated cells. 
The major limitation to isolation and excision of the aorta is that the animal must be sacrificed, especially in the cases of longitudinal studies. Currently, there is no single technique comparable to isolation and excision of the murine aorta. Small animal imaging technologies is becoming more advanced and approaching characterization capabilities of direct observation however it continues to have limitations including cost8. Immortalized cells lines can be used for in vitro studies however immortal cells are not as useful as primary isolated cells for in vitro assays especially for viability studies9. Isolation and excision of the murine aorta is currently the most versatile technique that can be used in the study of aortic disease.

The aorta plays a pivotal role in cardiovascular function supplying the body with oxygenated blood and similar to others portions of the body, is susceptible to disease. Common aortic diseases include atherosclerosis and aneurysm, which are the results of genetic and environmental factors including diet, smoking and sedentary lifestyle1. Atherosclerosis is the deposition of a calcium- and lipid-based plaque to the aortic wall typically found in patients with chronic hyperlipidemia2. Aneurysms are characterized by degradation of the structural components of the aorta and thinning of the vessel wall, followed by an increased diameter which could ultimately lead to rupture3.
Animal models are important tools used to study the mechanism of disease and efficacy of potential treatments. Common animal models used in cardiovascular research, specifically research investigating vascular and metabolic disorders include genetically modified mice to alter lipid levels such as apolipoprotein E gene knockout and low density lipoprotein receptor gene knockout mice4. The majority of methods to evaluate mechanisms of disease and efficacy of therapy would include the isolation and excision of the aorta.
Once the aorta is localized and isolated, morphometric analysis can be determined, such as presence of aneurysm, typically defined as a greater than 50% increase in diameter5. After necessary in situ analysis is complete, the aorta can be excised for further analysis. An excised aorta can be flash frozen to conduct molecular studies such as protein and/or gene expression assays or fixed using 4% paraformaldehyde and later embedded, sectioned and stained for histological analysis. Histological analysis of the aorta can demonstrate common features of aortic disease such as structural degradation, plaque formation, and infiltration of leukocytes6,7. Additionally, an excised aorta can be used to isolate primary cell lines including endothelial and smooth muscle cells which can subsequently be used for a variety of in vitro studies7.
Currently, there are no other methods to provide this in-depth characterization of aortic disease as well as provide researchers with tools to further study cardiovascular disease. Imaging modalities such as magnetic resonance imaging, computed tomography and ultrasonography are the closest methods to morphologically evaluate the aorta, however this is difficult in small animals and obtaining a device with adequate technology is expensive8. Immortalized cell lines can be purchased to investigate potential mechanisms of disease and efficacy of therapies, however the artificial nature of these cells are limiting in studying the effects on the cell life cycle and apoptosis9.
The overall goal of this manuscript is to demonstrate the sterile isolation and excision of the murine aorta in the investigation of cardiovascular disease.

<table><tbody><tr><td>Isoflurane</td><td>Med-Vet International</td><td>#RXISO-250</td><td></td></tr><tr><td>70% ethanol</td><td>Fisher</td><td>07-678-001</td><td></td></tr><tr><td>Phosphate buffered saline</td><td>Sigma Aldrich</td><td>P5368-10PAK</td><td></td></tr><tr><td>Surgical tape</td><td>3M</td><td>1527-1</td><td></td></tr><tr><td>Sterile gauze</td><td>Dukal Corporations</td><td>1312</td><td></td></tr><tr><td>25 gauge needle</td><td>BD</td><td>305122</td><td></td></tr><tr><td>10 ml syringe</td><td>BD</td><td>309604</td><td></td></tr></tbody></table>

isolation and excision of murine aorta; a versatile technique in the study of cardiovascular disease

Cardiovascular disease is a broad term describing disease of the heart and/or blood vessels. The main blood vessel supplying the body with oxygenated blood is the aorta. The aorta may become affected in diseases such as atherosclerosis and aneurysm. Researchers investigating these diseases would benefit from direct observation of the aorta to characterize disease progression as well as to evaluate efficacy of potential therapeutics. The goal of this protocol is to describe proper isolation and excision of the aorta to aid investigators researching cardiovascular disease. Isolation and excision of the aorta allows investigators to look at gross morphometric changes as wells as allowing them to preserve and stain the tissue to look at histologic changes if desired. The aorta may be used for molecular studies to evaluate protein and gene expression to discover targets of interest and mechanisms of action. This technique is superior to imaging modalities as they have inherent limitations in technology and cost. Additionally, primary isolated cells from a freshly isolated and excised aorta can allowing researchers to perform further in situ and in vitro assays. The isolation and excision of the aorta has the limitation of having to sacrifice the animal however, in this case the benefits outweigh the harm as it is the most versatile technique in the study of aortic disease.

Upon completion of the procedure, there will be an intact aorta originating from the heart, descending into the thoracic and abdominal cavities with the renal arteries still attached (Figure 1A). From here, the aorta can be imaged in situ to quantify morphometric changes which are diagnostic in the study of abdominal aortic aneurysms (Figure 1B and 1C). Subsequently, the aorta can be removed, fixed and stained to look at histological changes. A general and common stain of the aorta is the hematoxylin and eosin stain (Figure 2A and 2B). Additionally, the structural integrity of the aorta can be qualitatively quantified using Verhoff van Geison staining to look at the elastin bands (Figure 2C and 2D). Instead of obtaining a histological analysis, the investigator may flash freeze the aorta for subsequent protein and ribonucleic acid expression. The final option for the investigator is to use the aorta to obtain primary cell isolation. These cells can be grown in culture (Figure 3A) and used for a variety of in vitro studies including viability studies (Figure 3B) and protein localization (Figure 3C).
<img alt="Figure 1" src="/files/ftp_upload/52172/52172fig1.jpg" width="700" /> 
Figure 1. In situ representative images of murine aorta. (A) Depiction of the normal mouse anatomy after the isolation of the aorta including the heart and kidneys. (B) Magnified image of a normal intact murine abdominal aorta. (C) Magnified image of a diseased abdominal aortic with an aneurysm in the suprarenal region. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52172/52172fig1highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" src="/files/ftp_upload/52172/52172fig2.jpg" width="700" /> 
Figure 2. Histological analysis of murine aorta. (A) Representative image of a normal hematoxylin and eosin stain of a healthy suprarenal aorta at 20X magnification. (B) Representative image of an aneurismal suprarenal aorta with intramural thrombus after hematoxylin and eosin stain at 20X magnification. (C) Representative image of a Verhoff van Geison stain, highlighting the elastin bands of a normal suprarenal aorta at 10X magnification. (D) Representative image of a Verhoff van Geison stain highlighting the elastin bands of a suprarenal aorta developing disease noted by the thinning and striating of elastin bands and thickening of the adventitial layer. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52172/52172fig2highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" src="/files/ftp_upload/52172/52172fig3.jpg" width="700" /> 
Figure 3. Primary aortic myocytes cultured from aorta. (A) Representative image of primary aortic myocytes in culture at 20X magnification obtained from the abdominal aorta. (B) Representative image of primary aortic myocytes during a Trypan blue exclusion assay after a 500 &#181;M treatment of H2O2 at 20X magnification obtained from the abdominal aorta. (C) Representative image of an immunohistochemistry stain for alpha actin in primary isolate aortic smooth muscle cells from the abdominal aorta. <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52172/52172fig3highres.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Isolation and Excision of Murine Aorta; A Versatile Technique in the Study of Cardiovascular Disease at JoVE.com

Isolation and Excision of Murine Aorta; A Versatile Technique in the Study of Cardiovascular Disease

Pathology of the aorta can lead to severe morbidity and mortality, therefore research of disease progression and potential therapies is warranted. Here, we present a protocol to isolate and excise the murine aorta to aid researchers in their investigation of cardiovascular disease.

Cardiovascular disease is a broad term describing disease of the heart and/or blood vessels. The main blood vessel supplying the body with oxygenated ...

isolation-excision-murine-aorta-versatile-technique-study

Nanyang Technological University

Research

JoVE Journal

Medicine

32.3K Views.  University of Cincinnati College of Medicine. Pathology of the aorta can lead to severe morbidity and mortality, therefore research of disease progression and potential therapies is warranted. Here, we present a protocol to isolate and excise the murine aorta to aid researchers in their investigation of cardiovascular disease. 

Video: Isolation and Excision of Murine Aorta; A Versatile Technique in the Study of Cardiovascular Disease

Orthotopic Aortic Transplantation in Mice for the Study of Vascular Disease

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. This is largely true, but there are a number of important principles that can reduce the difficulty of these procedures and enhance reproducibility. Orthotopic aortic transplantation is an excellent procedure in which to learn these principles because it involves only two end-to-end anastomoses, but requires good suturing technique and handling of the vessels for consistent success. This procedure begins with the procurement of a length of abdominal aorta from a donor animal, followed by division of the native aorta in the recipient. The procured aorta is then placed between the divided ends of the recipient aorta and sutured into place using end-to-end anastomoses. To accomplish this objective successfully requires a high degree of concentration, good tools, a steady hand, and an appreciation of how easily the vasculature of a mouse can be damaged, resulting in thrombosis. Learning these important principles is what occupies most of the beginner's time when learning microsurgery in small rodents. Throughout this protocol, we refer to these important points. This model can be used to study vascular disease in a variety of different experimental systems1-8. In the context shown here, it is most often used for the study of post-transplant vascular disease, a common long-term complication of solid organ transplantation in which intimal hyperplasia occurs within the allograft. The primary advantage of the model is that it facilitates quantitative morphometric analyses and the transplanted vessel lies contiguous to the endogenous vessel, which can serve as an additional control9. The technique shown here is most often used for mice weighing 18-25 grams. We have accumulated most of our experience using the C57BL/6J, BALB/cJ, and C3H/HeJ strains.

We describe a technique in which a section of the abdominal aorta from a mouse is transplanted orthotopically to just below the renal arteries in an allogeneic or syngeneic recipient. This technique can be useful in studies in which transplantation of large arteries of uniform size is deemed advantageous.

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. ...

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 ...

Murine Cervical Aortic Transplantation Model using a Modified Non-Suture Cuff Technique

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. However, only minor improvement in the long-term results of transplanted solid organs could be observed over the past decades. In this context, chronic allograft vasculopathy (CAV) still represents the leading cause of late organ failure in cardiac, renal and pulmonary transplantation.
Thus far, the underlying pathogenesis of CAV development remains unclear, explaining why effective treatment strategies are presently missing and emphasizing a need for relevant experimental models in order to study the underlying pathophysiology leading to CAV formation. The following protocol describes a murine heterotopic cervical aortic transplantation model using a modified non-suture cuff technique. In this technique, a segment of the thoracic aorta is interpositioned in the right common carotid artery. With the use of the non-suture cuff technique, an easy to learn and reproducible model can be established, minimizing the possible heterogeneity of sutured vascular micro anastomoses.

Here, we present a protocol of heterotopic aortic transplantation in mice using the non-suture cuff technique in a cervical murine model. This model can be used to study the underlying pathology of chronic allograft vasculopathy (CAV) and can help evaluate new therapeutic agents in order to prevent its formation.

With the introduction of powerful immunosuppressive protocols, distinct advances are possible in the prevention and therapy of acute rejection episodes. ...

Modifications of the Langendorff Method for Simultaneous Isolation of Atrial and Ventricular Myocytes from Adult Mice

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction and electrical activity. Hence, isolating viable, high-quality cardiomyocytes from the heart is the initial and most crucial experimental step. Comparing the various protocols for isolating the cardiomyocytes of adult mice, the Langendorff retrograde perfusion is the most successful and reproducible method reported in the literature, especially for isolating ventricular myocytes. However, isolating quality atrial myocytes from the perfused heart remains challenging, and few successful isolation reports are available. Solving this complicated problem is extremely important because apart from ventricular disease, atrial disease accounts for a large part of heart diseases. Therefore, further investigations on the cellular level to reveal the mechanisms are warranted. In this paper, a protocol based on the Langendorff retrograde perfusion method is introduced and some modifications in the depth of aorta cannulation and the steps that may affect the digestion process to isolate atrial and ventricular myocytes were simultaneously made. Moreover, the isolated cardiomyocytes are confirmed to be amenable to patch clamp investigation.

This protocol describes modifications of the Langendorff method including the depth of aorta cannulation for simultaneous Isolation of atrial and ventricular myocytes from adult mice.

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction ...

Isolation and Primary Culture of Mouse Aortic Endothelial Cells

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an important model for cardiovascular disease research. This study demonstrates a simple method to isolate and culture endothelial cells from the mouse aorta without any special equipment. To isolate endothelial cells, the thoracic aorta is quickly removed from the mouse body, and the attached adipose tissue and connective tissue are removed from the aorta. The aorta is cut into 1 mm rings. Each aortic ring is opened and seeded onto a growth factor reduced matrix with the endothelium facing down. The segments are cultured in endothelial cell growth medium for about 4 days. The endothelial sprouting starts as early as day 2. The segments are then removed and the cells are cultured continually until they reach confluence. The endothelial cells are harvested using neutral proteinase and cultured in endothelial cell growth medium for another two passages before being used for experiments. Immunofluorescence staining indicated that after the second passage the majority of cells were double positive for Dil-ac-LDL uptake, Lectin binding, and CD31 staining, the typical characteristics of endothelial cells. It is suggested that cells at the second to third passages are suitable for in vitro and in vivo experiments to study the endothelial biology. Our protocol provides an effective means of identifying specific cellular and molecular mechanisms in endothelial cell physiopathology.

The vascular endothelial cells play a significant role in many important cardiovascular disorders. This article describes a simple method to isolate and expand endothelial cells from the mouse aorta without using any special equipment. Our protocol provides an effective means of identifying mechanisms in endothelial cell physiopathology.

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an ...

Biology

Isolation of Murine Coronary Vascular Smooth Muscle Cells

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs from the coronary circulation. Hearts with intact aortic arches were removed and perfused via retrograde Langendorff with digestion solution containing 300 Units/ml of collagenase type II, 0.1 mg/ml soybean trypsin inhibitor and 1 M CaCl2. The perfusates were collected at 15 min intervals for 90 min, pelleted by centrifugation, resuspended in plating media, and plated on tissue culture dishes. VSMCs were characterized by presence of SM22&#945;, &#945;-SMA, and vimentin. One of the main advantages of using this technique is the ability to isolate VSMCs from the coronary circulation of mice. Although the small number of cells obtained can limit some of the applications for which the cells can be utilized, isolated coronary VSMCs can be used in a variety of well-established cell culture techniques and assays. Studies investigating VSMCs from genetically modified mice can provide further information about structure-function and signaling processes associated with vascular pathologies.

The purpose of this protocol is to demonstrate the isolation and culture techniques of murine primary vascular smooth muscle cells (VSMCs) from the coronary circulation. Once VSMCs have been isolated, they can be used for many standard culture techniques.

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs ...

Murine Aortic Crush Injury: An Efficient In Vivo Model of Smooth Muscle Cell Proliferation and Endothelial Function

Arterial reconstruction, whether angioplasty or bypass surgery, involves iatrogenic trauma causing endothelial disruption and vascular smooth muscle cell (VSMC) proliferation. Common murine models study small vessels such as the carotid and femoral arteries. Herein we describe an in vivo system in which both VSMC proliferation and endothelial barrier function can be simultaneously assessed in a large vessel. We studied the infrarenal aortic response to injury in C57BL/6 mice. The aorta was injured from the left renal vein to the aortic bifurcation by 30 transmural crushes of 5-seconds duration with a cotton-tipped applicator. Morphological changes were assessed with conventional histology. Aorta wall thickness was measured from the luminal surface to the adventitia. EdU integration and counter staining with DAPI and alpha-actin was used to demonstrate VSMC proliferation. Activation of ERK1/2, a known moderator of intimal hyperplasia formation, was determined by Western Blot analysis. The effect of inflammation was determined by immunohistochemistry for B-cells, T-cells, and macrophages. En face sections of endothelium were visualized with scanning electron microscopy (SEM). Endothelial barrier function was determined with Evans Blue staining. Transmural injury resulted in aortic wall thickening. This injury induced VSMC proliferation, most prominently at 3 days after injury, and early activation of ERK1/2 and decreased p27kip1 expression. Injury did not result in increased B-cells, T-cells, or macrophages infiltration in the vessel wall. Injury caused partial endothelial cell denudation and loss of cell-cell contact. Injury resulted in a significant loss of endothelial barrier function, which returned to baseline after seven days. The murine transmural blunt aortic injury model provides an efficient system to simultaneously study both VSMC proliferation and endothelial barrier function in a large vessel.

Murine Aortic Crush Injury: An Efficient In Vivo Model of Smooth Muscle Cell Proliferation and Endothelial Function

Restenosis following cardiovascular procedures (bypass surgery, angioplasty, or stenting) is a significant problem reducing the durability of these procedures. An ideal therapy would inhibit smooth muscle cell (VSMC) proliferation while promoting regeneration of the endothelium. We describe a model for simultaneous assessment of VSMC proliferation and endothelial function in vivo.

Arterial reconstruction, whether angioplasty or bypass surgery, involves iatrogenic trauma causing endothelial disruption and vascular smooth muscle cell ...

A Modified Technique for Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of pressure overload in mouse models. The main challenge of this procedure is to clearly visualize the transverse aortic arch and precisely band the target vessel. Classical approaches perform a partial thoracotomy to expose the transverse aortic arch. However, it is an open-chest model that causes a rather large surgical trauma and requires a ventilator during the surgery. To prevent unnecessary trauma and simplify the operating procedure, the aortic arch is approached via the proximal proportion of the sternum, reaching and binding the target vessel using a small self-made retractor that contains a snare. This procedure can be conducted without entering the pleura cavity and does not need a ventilator or microsurgical operation, which leaves the mice with physiological breathing patterns, simplifies the procedure, and significantly reduces operation time. Due to the less invasive approach and less operation time, mice can undergo fewer stress reactions and recover rapidly.

The present protocol describes a modified and simplified technique with a minimally invasive transverse aortic constriction (TAC) procedure using a self-made retractor. This procedure can be conducted without a ventilator or microscope and introduces pressure overload, eventually leading to cardiac hypertrophy or heart failure.

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of ...

Isolation and Analysis of Aortic Arch and Root Lesions in an Atherosclerotic Mouse Model

Atherosclerosis, a leading cause of cardiovascular diseases, necessitates a detailed examination of lesion development and progression. This study introduces a comprehensive protocol for the isolation and histological analysis of aortic arch and root lesions in a widely used atherosclerotic mouse model, low-density lipoprotein receptor knock-out (Ldlr-/-) mice. The aortic arch and root are key sites for atherosclerotic lesions, and their examination is critical for assessing the onset, progression, or regression of atherosclerosis, predicting cardiovascular event risks, and identifying potential therapeutic targets. This protocol outlines methods for quantifying atherosclerotic burden in the aortic arch and root, including tissue isolation, fixation, Oil Red O staining, aortic root sectioning, Hematoxylin and Eosin (HE) staining, Verhoeff-Van Gieson (VVG) staining, and image analysis. Oil Red O staining measures plaque area in the aortic arch, evaluating the severity of atherosclerosis, while HE staining of the aortic root reveals plaque components such as the lipid core and fibrous cap, facilitating the assessment of plaque stability and rupture risk. VVG staining can stain collagen fibers within tissues, providing further insights into plaque composition and related information. This thorough analysis offers valuable insights into the mechanisms of lesion development and may guide the creation of novel therapeutic strategies for preventing and treating atherosclerosis.

This protocol provides a comprehensive methodology for the quantitative analysis of atherosclerotic plaques to facilitate more in-depth research into the mechanisms and progression of atherosclerosis.

Atherosclerosis, a leading cause of cardiovascular diseases, necessitates a detailed examination of lesion development and progression. This study ...

Surgical Aortic Debanding: A Procedure to Study Left Ventricular Reverse Remodeling in Murine Model of Aortic Constriction

Source: Goncalves-Rodrigues, P. et al. <a href="https://www-jove-com.bdigitaluss.remotexs.co/video/60036" target="_blank">Studying Left Ventricular Reverse Remodeling by Aortic Debanding in Rodents</a>. J. Vis. Exp. (2021)
This video demonstrates the technique of aortic debanding, which can lead to reverse remodeling to limit the progression towards heart failure in a murine model. Post debanding, a significant reduction of ventricular afterload triggers regression of ventricular hypertrophy and fibrosis, causing a recovery in cardiac function.

Isolation and Excision of Murine Aorta; A Versatile Technique in the Study of Cardiovascular Disease

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Isolation and Analysis of Aortic Arch and Root Lesions in an Atherosclerotic Mouse Model

Surgical Aortic Debanding: A Procedure to Study Left Ventricular Reverse Remodeling in Murine Model of Aortic Constriction