This work was supported by grants from the National Natural Science Foundation of China (81930007, 81625002, 81800307, 81470389, 81500221, 81770238), the Shanghai Outstanding Academic Leaders Program (18XD1402400), the Science and Technology Commission of Shanghai Municipality (201409005200), Shanghai Pujiang Talent Program (2020PJD030), and China Postdoctoral Science Foundation (2020M671161, BX20190216).

The experiments involving animal work are performed with all necessary approvals from the Laboratory Animal Welfare Ethics Committee of Renji Hospital, Shanghai Jiao Tong University, School of Medicine (R52021-0506). Female and male C57BL/6J mice aged between 8-10 weeks were used in the study.
1. Preparation of the simplified anesthesia equipment (OPTIONAL)
NOTE: This is an optional pre-operative set up and can be replaced with titratable anesthesia as mentioned in section 2. The institutional animal ethics committee and veterinarian(s) should be consulted prior to adapting this set up in animal procedures.
<ol>
	<li>Take a 15 mL centrifuge tube, and make a cut perpendicular to the long axis of the tube about 3 cm from the opening. 
	NOTE: Ensure that the cut is greater than half of the circular circumference of the tube lumen so that the valve can be successfully inserted.</li>
	<li>Drill holes (diameter, 2 mm) at the centrifuge tube wall between the cut and the tube opening.</li>
	<li>Cut a suitably sized piece of the valve from a plastic sheet and insert the valve into the cut on the tube wall. 
	NOTE: The valve can be used to control the release rate of isoflurane by changing the depth of the insertion.</li>
	<li>Inside a fume hood, cut open the bottom of the tube and connect it to the oxygen supply. Place a cotton ball near the bottom end of the tube, add load 0.5 mL isoflurane (as obtained, see Table of Materials) onto the cotton ball, and close the valve.</li>
	<li>Test the anesthesia efficacy by masking the mice with tubes prepared as described above. Monitor the breathing rate and anesthesia depth by toe pinch response. 
	&#8203;NOTE: A breathing rate less than 10 times/10 s suggests excessive anesthesia, and the insertion depth of the valve should be adjusted.&#160;For all the procedures involving anesthesia, a gas filter filled with activated charcoal sheets must be used (Figure 1A-i), and surgery should be performed within a hood.</li>
</ol>
2. Operative preparation and anesthesia
<ol>
	<li>Prepare and sterilize all the required instruments on the day of surgery, including a pair of forceps, a micro-mosquito hemostat, a pair of surgical scissors, two pairs of needle holders, 4-0 silk surgical suture, 6-0 silk surgical suture, a gas filter, and a light source (see Table of Materials) (Figure 1A).</li>
	<li>Put on a surgical mask and sterile gloves.</li>
	<li>Apply the depilatory cream to the mouse chest and wait for 1 min. Gently wipe off the depilatory cream and hair with wet gauze.</li>
	<li>Hold the mouse with the dominant hand after depilation.&#160;Induce anesthesia via inhalation of vaporized isoflurane (4%) with oxygen supply (1L/min) and maintain at 2-3% isoflurane.</li>
	<li>Confirm adequate anesthesia by the lack of toe pinch response.</li>
	<li>Apply sterile eye cream to both eyes to prevent corneal dryness.</li>
	<li>Secure the mice on a surgery platform in the supine position. Apply povidone-iodine swabs (see Table of Materials) to the chest three times and cover the disinfected chest with a sterile drape.</li>
</ol>
3. Induction of myocardial infarction
<ol>
	<li>Change the contaminated gloves to ensure sterility.</li>
	<li>Make a 0.5 cm skin cut along the line connecting the xiphoid and armpit after local block with lidocaine.</li>
	<li>Bluntly separate the pectoral major and pectoral minor muscles using forceps and a micro-mosquito hemostat to expose the fourth intercostal space.</li>
	<li>Open the fourth intercostal space using a micro-mosquito hemostat.</li>
	<li>Externalize the heart by pushing the heart toward the fourth intercostal space with the index finger of the left hand.</li>
	<li>Secure the heart with the left hand, and ligate the left anterior descending branch with a 6-0 suture 3 mm from its origin.</li>
	<li>Place the heart back into the thoracic cavity quickly. 
	NOTE: It is safe to externalize the heart for less than 30 s.</li>
	<li>Evacuate the air out of the thoracic cavity by a gentle press of the chest cavity manually.</li>
	<li>Close the muscle layer over the ribs with a 6-0 silk suture.</li>
	<li>Close the skin with a 4-0 silk suture.</li>
	<li>Place the mice on a pad (37 &#176;C) immediately after the operation.</li>
	<li>Inject buprenorphine (0.05-0.1mg/kg) subcutaneously every 4-6 hours to reduce post-operative pain for up to 72 hours.</li>
	<li>Return the operated mice to cages when fully recovered. 
	NOTE: The mice will be fully recovered within 3-5 min after surgery.</li>
	<li>Carefully monitor the mice and provide wet food for up to 7 days.</li>
</ol>
4. Harvesting the tissues
<ol>
	<li>Sacrifice the mice at different time points after MI establishment by cervical dislocation.</li>
	<li>Secure the sacrificed mice on the surgery platform in the supine position.</li>
	<li>Make a ventral incision (~3-4 cm) in the upper abdomen. Cut off the ribs from both sides of the thorax cavity, and remove the diaphragm.</li>
	<li>Perfuse the heart with 10 mL cold phosphate-buffered saline (1x PBS, 4 &#176;C) through intraventricular injection.</li>
	<li>Collect the heart by cutting off the aortic root and immediately store the heart at -80 &#176;C. 
	NOTE: According to the authors&#39; experience, it is feasible to perform TTC staining within two weeks of storage.</li>
	<li>Stain the heart with 2,3,5-Triphenyltetrazolium chloride (TTC).
	<ol>
		<li>Slice the frozen heart into 1 mm thick sections on ice using razor blades.</li>
		<li>Incubate the prepared heart slices in 1% TTC solution (dissolved in 1x PBS) at 37 &#176;C for 10-15 min. 
		NOTE: After 15 min incubation, discard the TTC solution and immerse the stained heart slices into 1x PBS.</li>
	</ol>
	</li>
	<li>Photograph the slices using a digital camera.</li>
</ol>

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The authors have nothing to disclose.

The present report demonstrated a easy&#160;protocol for MI induction in mice with readily available materials, which was modified from a method reported by Gao16. Murine MI models are indispensable for mechanistic exploration and drug screen for post-MI dysfunction and remodeling12. Among the existing techniques for MI induction, coronary artery ligation represents the most commonly practiced one. Coronary artery ligation faithfully recapitulates the ischemia nature of myo...

Myocardial infarction (MI) represents one of the significant causes of death and disability worldwide1,2,3,4,5. Despite timely reperfusion, there is currently a lack of effective therapies to treat post-MI cardiac remodeling. Correspondingly, considerable efforts have been made to mechanistic exploration and therapy exploitation for MI6,7,8. Of note, the establishment of MI models is a prerequisite to meet these ends.
Several methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been proposed to induce MI models in small animals. Isoproterenol treatment is a simple method for MI induction, but it cannot induce infarction of the targeted area9. Cryoinjury leads to myocardial necrosis via the generation of ice crystals and disruption of the cell membrane rather than direct ischemia10. By contrast, coronary artery ligation permits precise control of occlusion site and extent of infarct area and faithfully recapitulates remodeling response following infarction11,12. Coronary artery ligation is typically performed following intubation, mechanical ventilation, and thoracotomy, which is technically challenging13,14. Several modified protocols for coronary artery ligation (e.g., ventilation free) were reported and potentiated the induction of MI, but detailed visual demonstrations are lacking15,16,17. These issues pose a significant financial and technical barrier for groups wishing to engage in research using MI models. This report presents an approach for induction of MI in mice. The current method is easy, timesaving, and uses surgical tools and equipment found readily in most laboratories.

<table><tbody><tr><td>2,3,5-Triphenyltetrazolium chloride</td><td>SIGMA</td><td>T8877-25G</td><td>TTC staining</td></tr><tr><td>4-0 silk suture</td><td>YUANKANG</td><td>4-0</td><td>Surgical instrument</td></tr><tr><td>Autoclave</td><td>HIRAYAMA</td><td>HVE-50</td><td>Sterilization for the solid</td></tr><tr><td>Buprenorphine</td><td>Qinghai Pharmaceutical FACTORY Co., Ltd.</td><td>H10940181</td><td>reduce post-operative pain</td></tr><tr><td>Centrifugation tube</td><td>Biological Hope</td><td>1850-K</td><td>15ML</td></tr><tr><td>Depilatory cream</td><td>ZIKER BIOTECHNOLOGY</td><td>ZK-L2701</td><td>Depilation agent for laboratory animals</td></tr><tr><td>Forcep</td><td>RWD</td><td>F12028</td><td>Surgical instrument</td></tr><tr><td>Gas filter</td><td>ZHAOXIN</td><td>SA-493</td><td>Operator protection</td></tr><tr><td>Isoflurane</td><td>RWD</td><td>20071302</td><td>Used for anesthesia</td></tr><tr><td>Light source</td><td>Beijing PDV</td><td>LG-150B</td><td>Operating lamp</td></tr><tr><td>Micro-mosquito hemostat</td><td>FST</td><td>13011-12</td><td>Surgical instrument</td></tr><tr><td>Needle</td><td>BINXIONG</td><td>42180104</td><td>Surgical instrument</td></tr><tr><td>Needle and the 6-0 silk suture</td><td>JIAHE</td><td>SC086</td><td>Surgical instrument</td></tr><tr><td>Needle holder</td><td>ShangHaiJZ</td><td>J32030</td><td>Surgical instrument</td></tr><tr><td>Needle holder</td><td>ShangHaiJZ</td><td>J32010</td><td>Surgical instrument</td></tr><tr><td>Povidone-iodine swabs</td><td>SingleLady</td><td>GB26368-2010</td><td>Skin disinfection</td></tr><tr><td>Scissors</td><td>CNSTRONG</td><td>JYJ1030</td><td>Surgical instrument</td></tr><tr><td>Sterile eye cream</td><td>Shenyang Xingqi Pharmaceutical Co., Ltd.</td><td>H10940177</td><td>prevent corneal dryness</td></tr><tr><td>Ultra-high resolution ultrasound imaging system for small animals</td><td>VisualSonics</td><td>Vevo 2100</td><td>Echocardiographic analysis</td></tr></tbody></table>

a modified simple method for induction of myocardial infarction in mice

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI remodeling and evaluation of novel therapeutics. Different methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been used to induce MI. Compared with isoproterenol treatment and cryoinjury, coronary artery ligation may better reflect the ischemic response and chronic remodeling after MI. However, traditional methods for coronary ligation in mice are technically challenging. The current study describes a simple and efficient process for induction of MI in mice with readily available materials. The mouse chest skin was cut open under stable anesthesia. The heart was immediately externalized through the intercostal space after blunt separation of the pectoralis major and pectoralis minor. The left anterior descending branch (LAD) was ligated with a 6-0 suture 3 mm from its origin. Following LAD ligation, staining with 2,3,5-Triphenyltetrazolium chloride (TTC) indicated successful induction of MI and temporal changes of post-MI scar size. Meanwhile, survival analysis results showed overt mortality within 7 days after MI, mainly due to cardiac rupture. Moreover, post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. Once mastered, an MI model can be established in mice within 2-3 min with readily available materials.

The experimental protocol and some of the critical steps are shown in Figure 1. The simplified anesthesia equipment induced anesthesia. As shown in Figure 2A, the induced anesthesia was stable, as reflected by the regular breathing rates (varied from 90-107 breaths/min in the tested mice). Following coronary artery ligation, TTC staining analysis indicated successful induction of myocardial infarction and temporal changes of post-MI scar size (<strong class="xfi...

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A Modified Simple Method for Induction of Myocardial Infarction in Mice

Under adequate anesthesia, the mouse heart was externalized through the intercostal space, and myocardial infarction was successfully induced by ligating the left anterior descending artery (LAD) using materials readily available in most laboratories.

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI ...

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3.5K Views.  The First Affiliated Hospital of Bengbu Medical College. Dit rapport presenteert een unieke aanpak voor de inductie van een hartinfarct bij muizen. De huidige methode is eenvoudig, tijdbesparend en maakt gebruik van de chirurgische buizen en apparatuur die in de meeste laboratoria te vinden zijn. Het opstellen van myocardinfarctenmodellen biedt een uitgangspunt voor het onderzoeken van de mechanismen uit het verleden van post-MI-remodellering en variatie van nieuwe therapieën.Breng de ontharingscrème aan op de borst van de muis en wacht ee...

Video: A Modified Simple Method for Induction of Myocardial Infarction in Mice

Modified Technique for Coronary Artery Ligation in Mice

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI we need better knowledge about pathophysiology of myocardial ischemia. This knowledge may be valuable to define new therapeutic targets for innovative cardiovascular therapies4. Experimental MI model in mice is an increasingly popular small-animal model in preclinical research in which MI is induced by means of permanent or temporary ligation of left coronary artery (LCA)5. In this video, we describe the step-by-step method of how to induce experimental MI in mice.
The animal is first anesthetized with 2% isoflurane. The unconscious mouse is then intubated and connected to a ventilator for artificial ventilation. The left chest is shaved and 1.5 cm incision along mid-axillary line is made in the skin. The left pectoralis major muscle is bluntly dissociated until the ribs are exposed. The muscle layers are pulled aside and fixed with an eyelid-retractor. After these preparations, left thoracotomy is performed between the third and fourth ribs in order to visualize the anterior surface of the heart and left lung. The proximal segment of LCA artery is then ligated with a 7-0 ethilon suture which typically induces an infarct size ~40% of left ventricle. At the end, the chest is closed and the animals receive postoperative analgesia (Temgesic, 0.3 mg/50 ml, ip). The animals are kept in a warm cage until spontaneous recovery.

The surgical procedure used to induce experimental myocardial infarction in mice begins with left thoracotomy between the third and the fourth ribs in order to visualize the anterior surface of the heart and left lung. The left coronary artery is ligated, the chest is closed and the mouse is allowed to recover spontaneously.

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality worldwide. In humans, a pathologic occlusion forms in a coronary artery and reperfusion of that occluded artery is considered essential to maintain viability of the myocardium at risk. Although essential for myocardial recovery, reperfusion of the ischemic myocardium creates its own tissue injury. The physiologic response and healing of an ischemia/reperfusion injury is different from a chronic occlusion injury. Myocardial ischemia/reperfusion injury is gaining recognition as a clinically relevant model for myocardial infarction studies. For this reason, parallel animal models of ischemia/reperfusion are vital in advancing the knowledge base regarding myocardial injury. Typically, ischemia of the mouse heart after left anterior descending (LAD) coronary artery occlusion is confirmed by visible pallor of the myocardium below the occlusion (ligature). However, this offers only a subjective way of confirming correct or consistent ligature placement, as there are multiple major arteries that could cause pallor in different myocardial regions. A method of recording electrocardiographic changes to assess correct ligature placement and resultant ischemia as well as reperfusion, to supplement observed myocardial pallor, would help yield consistent infarct sizes in mouse models. In turn, this would help decrease the number of mice used. Additionally, electrocardiographic changes can continue to be recorded non-invasively in a time-dependent fashion after the surgery. This article will demonstrate a method of electrocardiographically confirming myocardial ischemia and reperfusion in real time.

During murine myocardial ischemia/reperfusion surgery, correct placement of the occluding ligature is typically confirmed by visible observation of myocardial pallor. Herein, a method of electrocardiographically confirming ischemia and reperfusion, to supplement observed myocardial pallor, is demonstrated in male C57Bl/6 mice.

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality ...

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine models of MI with permanent ligation of left-anterior descending (LAD) coronary artery closely mimics MI in humans. Murine models benefit from the extensive genetic engineering available nowadays. Here we propose a reproducible murine surgical model of myocardial infarction by permanent LAD coronary ligation. Our technique comprises anesthesia with ketamine/xylazine that can be rapidly reversed by administration of an antagonist, intubation without tracheotomy for mechanical-assisted ventilation, ventilation with application of extrinsic positive end-expiratory pressure (PEEP) to avoid alveolar collapse, a thoracotomy method limiting to the minimum surgical lesions made to skeletal muscles, and lung inflation without thoracentesis. This method is sparsely invasive, reproducible and reduces post-surgery mortality and complications.

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological processes.

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily and highly reproducible MI induction procedure is required to obtain further insight and better understanding of the underlying pathological changes. This procedure can also be used to evaluate the effects or potency of new and promising treatments (as drugs or interventions) in acute MI, subsequent remodeling and heart failure (HF). After intubation and pre-operative preparation of the animal, an anesthetic protocol with isoflurane was performed, and the surgical procedure was conducted&#160;quickly. Using a minimally invasive approach, the left anterior descending artery (LAD) was located and occluded by a ligature. The occlusion can be performed acutely for subsequent reperfusion (ischemia/reperfusion injury). Alternatively, the vessel can be ligated permanently to investigate the development of chronic MI, remodeling or HF. Despite common pitfalls, the drop-out rates are minimal. Various treatments such as remote ischemic conditioning can be examined for their cardioprotective potential pre-, peri- and post-operatively. The post-operative recovery was quick as the anesthesia was precisely controlled and the duration of the operation was short. Post-operative analgesia was administered for three days. The minimally invasive procedure reduces the risk of infection and inflammation. Furthermore, it facilitates rapid recovery. The &#8220;working heart&#8221; measurements were performed ex vivo and enabled precise control of preload, afterload and flow. This procedure requires specific equipment and training for adequate performance. This manuscript provides a detailed step-by-step introduction for conducting these measurements.

This article presents an efficient method to perform myocardial ischemia and subsequent chronic reperfusion in rats using a minimally invasive approach. In addition, left ventricular hemodynamic function of rats is assessed by echocardiography and isolated working heart methods.&#160;

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...

An Intact Pericardium Ischemic Rodent Model

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to induce myocardial injury). The majority of pre-clinical myocardial infarction models require the disruption of pericardial integrity with loss of the homeostatic cellular milieu. However, recently a methodology has been developed by us to induce myocardial infarction, which minimizes pericardial damage and retains the heart&#39;s resident immune cell population. An improved cardiac functional recovery in mice with an intact pericardial space following coronary ligation has been observed. This method provides an opportunity to study inflammatory responses in the pericardial space following myocardial infarction. Further development of the labeling techniques can be combined with this model to understand the fate and function of pericardial immune cells in regulating the inflammatory mechanisms that drive remodeling in the heart, including fibrosis.

This protocol outlines the steps for inducing myocardial infarction in mice while preserving the pericardium and its contents.

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to ...

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of heart reflow and induce secondary myocardial injury. A simple and reproducible model of myocardial infarction and myocardial ischemia-reperfusion injury is a good tool for researchers. Here, a customizable method to create a myocardial infarction (MI) model and MIRI by precision ligation of the left anterior descending coronary artery (LAD) through micromanipulation is described. Accurate and reproducible ligature positioning of the LAD helps obtain consistent results for heart injury. ST-segment changes can help to identify model accuracy. The serum level of cardiac troponin T (cTnT) is used to assess the myocardial injury, cardiac ultrasound is employed to evaluate the myocardial systolic function, and Evans-Blue/triphenyl tetrazolium chloride staining is used to measure infarct size. In general, this protocol reduces procedure duration, ensures controllable infarct size, and improves mouse survival.

Here we describe a simple and reproducible method that can induce myocardial infarction or myocardial ischemia-reperfusion injury in mice by precision ligation of the left anterior descending coronary artery through micromanipulation.

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of ...

Ultrasound-Guided Induced Pluripotent Stem Cell-Derived Cardiomyocyte Implantation in Myocardial Infarcted Mice

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a promising cell source for cardiac repair after ischemic damage. However, a low grafted rate is a significant obstacle for effective cardiac tissue regeneration after transplantation. This protocol shows that multiple hiPSC-CM ultrasound-guided percutaneous injections into an MI area effectively increase cell transplantation rates. The study also describes the entire hiPSC-CM culture process, pretreatment, and ultrasound-guided percutaneous delivery methods. In addition, the use of human mitochondrial DNA help detect the absence of hiPSC-CMs in other mouse organs. Lastly, this paper describes the changes in cardiac function, angiogenesis, cell size, and apoptosis at the infarcted border zone in mice 4 weeks after cell delivery. It can be concluded that echocardiography-guided percutaneous injection of the left ventricular myocardium is a feasible, relatively invasive, satisfactory, repeatable, and effective cellular therapy.

Ultrasound-guided cell delivery around the site of myocardial infarction in mice is a safe, effective, and convenient way of cell transplantation.

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem ...

Left Coronary Artery Ligation: A Surgical Murine Model of Myocardial Infarction

Ischemic heart disease and subsequent myocardial infarction (MI) is one of the leading causes of mortality in the United States and around the world. In order to explore the pathophysiological changes after myocardial infarction and design future treatments, research models of MI are required. Permanent ligation of the left coronary artery (LCA) in mice is a popular model to investigate cardiac function and ventricular remodeling post MI. Here we describe a less invasive, reliable, and reproducible surgical murine MI model by permanent ligation of the LCA. Our surgical model comprises of an easily reversible general anesthesia, endotracheal intubation that does not require a tracheotomy, and a thoracotomy. Electrocardiography and troponin measurement should be performed to ensure MI. Echocardiography at day 28 after MI will discern heart function and heart failure parameters. The degree of cardiac fibrosis can be evaluated by Masson's trichrome staining and cardiac MRI. This MI model is useful for studying the pathophysiological and immunological alterations after MI.

Presented here is a surgical procedure for permanent ligation of the left coronary artery in mice. This model can be used to investigate the pathophysiology and associated inflammatory response after myocardial infarction.

Ischemic heart disease and subsequent myocardial infarction (MI) is one of the leading causes of mortality in the United States and around the world. In ...

A Modified Simple Method for Induction of Myocardial Infarction in Mice

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