Name: apical resection mouse model to study early mammalian heart regeneration
Uploaded: 2016-01-23T15:00:00.000+00:00
Duration: 6 min 8 s
Description: Watch this Scientific Journal Video about Apical Resection Mouse Model to Study Early Mammalian Heart Regeneration at JoVE.com

作者感谢博士。詹姆斯·霍金斯，祖熙玉和禤去从国家心脏，肺和血液研究所（NHLBI）为他们的鼠标手术准备和石蜡切片染色的援助。作者感谢美国国立卫生研究院研究员编委会的编辑协助。

所有小鼠实验用协议号H0083R3批准的动物护理和使用计划，在美国国立卫生研究院（NIH）。本NHLBI IACUC认可无镇痛药的协议。 1.低温麻醉新生小鼠<ol><li>手术前消毒海绵和手术设备中的高压釜中。准备所有的手术材料和在加热珠灭菌15-20分钟切换提前达到240℃至270℃。 </li><li>传输所有C57BL / 6幼鼠（年龄P1）从哺乳的母亲到一个干净的鼠笼新鲜的床上用品和筑巢的材料。一旦幼仔取入手术室，迅速地进行根尖手术，以减少他们的花费的时间从母亲分离并降低产妇拆的风险。 </li><li>将海绵在冰床上，然后将一只小狗在海绵〜3分钟，实现低温麻醉。通过观察AP确认麻醉NEA和运动不能和捏一个后脚。检查新生儿的状态经常因为时间太少不会让小狗动性和呼吸暂停，和麻醉的时间过多会降低成活率12。 </li></ol> 2.开胸<ol><li>传送从冰床的小狗到外科台式区域，使用胶带来固定其手臂，腿和尾部在仰卧位置。 </li><li>消毒胸部用聚维酮碘，轻轻地用70％酒精消毒片进行清洁。 </li><li>做一个横向的皮肤切口，沿胸腔使用Vannas弹簧剪刀脚的第四肋间区域，然后生硬剖析第四肋间肌肉，以方便进入心脏。 注:生存率提高时，在手术过程中尽量减少失血。 </li></ol>心脏心室心尖3.手术截肢<ol><li>用手，轻轻涂抹于腹部压力exteriorize的顶点的心脏。吸收周围的血用无菌棉签涂抹清晰的可视化手术区。对于假手术对照新生儿，直接进入步骤4（缝合和恢复小鼠）。 </li><li>在放大镜灯，并使用虹膜切除术剪刀，直到低压室暴露轻轻地进行零碎切除左心室（LV）的。要小心，尽量减少LV的切除部分。大约15％的切除是必要实现低压室的最佳曝光。 </li><li>确保心脏返回到胸腔，一旦低压室暴露。 </li></ol> 4.缝合和小鼠恢复<ol><li>缝合肋和肌肉一起使用无菌脯氨酸6-0缝线以密封胸腔，然后用皮胶小心关闭皮肤切口部位。 </li><li>暖新生儿下为〜3分钟为恢复一加热灯，然后用70％的酒精消毒片befo清洁血液和胶的痕迹重新它重新引入到其同窝。尝试完成整个手术过程在10分钟内，因为减少花费从母体分离的时间，从而提高根尖切除后的小狗存活。 </li><li>以下各手术中，将手术工具与热珠灭菌的珠子接触，用于完全灭菌约20秒。允许外科工具，以各术前冷却至室温。 </li><li>完成手术的所有幼仔在产仔后，他们回到母亲的窝前将与母亲的床上用品和排泄物的幼崽。 注:一般情况下，ICR / CD-1小鼠是更好的养母不是C57BL / 6，但即使在相同的遗传背景的乳母，促进本能而有所不同。如果改变一个哺乳的母亲需要通过母体拆，以减少死亡率，取出P0幼崽哺乳的母亲，然后在P1进行根尖切除术。只有执行下列任一假手术或根尖řesection于幼崽一窝，因为混合假和手术的幼崽可以降低手术组幼崽6的存活率。 </li></ol> 5.后外科分析<ol><li>手术后的第二天，监视幼崽，确保有假和手术组间无差异，并计算幼仔的数量来衡量的存活率。如果手术被适当地进行时，存活率应当是在两个假和手术组中是相似和大于60％。 </li><li>心脏隔离和固定。 <ol><li>安乐死的幼崽在天1，并通过斩首和21日手术后2术后通过CO2的死亡颈椎脱位的保证，然后用70％的酒精准备擦拭胸部。 </li><li>切开胸部正中线皮肤和肌肉，然后打开箱子。 </li><li>消费税从胸腔整个心灵和修复5毫升4％多聚甲醛O / N在室温每个样本的整个心脏。 </li></ol></li><li>在第二天，转样本以70％的乙醇。样品可以存储最多一周石蜡包埋之前。 </li><li>片通过整个心室5-μm厚的石蜡切片，进行标准苏木精和曙红（H＆E）和Masson三色染色以检查再生反应5,7，具体而言，H＆E染色用于检查肌肉更换和马松三色染色用于研究纤维化反应5。 </li><li>选择感兴趣的区域，并设置了每个样品的至少三个焦点手动使用的滑动扫描器。图像，并根据制造商的使用默认参数的指令分析染色载玻片在40×放大率。 </li></ol>

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	<li>Lin, Z., Pu, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strategies+for+cardiac+regeneration+and+repair.">Strategies for cardiac regeneration and repair.</a> Sci Transl Med. 6, 231-239 (2014).</li><li>Xin, M., Olson, E. N., Bassel-Duby, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mending+broken+hearts:+cardiac+development+as+a+basis+for+adult+heart+regeneration+and+repair.">Mending broken hearts: cardiac development as a basis for adult heart regeneration and repair.</a> Nat Rev Mol Cell Biol. 14, 529-541 (2013).</li><li>Mahmoud, A. I., Porrello, E. 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I., Porrello, E. R., Kimura, W., Olson, E. N., Sadek, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surgical+models+for+cardiac+regeneration+in+neonatal+mice.">Surgical models for cardiac regeneration in neonatal mice.</a> Nat Protoc. 9, 305-311 (2014).</li><li>Allen, T. C., Prophet, E. B., Mills, B., Arrington, J. B., Sobin, L. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hematoxylin+and+eosin.">Hematoxylin and eosin.</a> Laboratory methods in Histotechnology. , 53-58 (1992).</li><li>Andersen, D. C., Ganesalingam, S., Jensen, C. H., Sheikh, S. 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A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-investigator+letter+on+reproducibility+of+neonatal+heart+regeneration+following+apical+resection.">Multi-investigator letter on reproducibility of neonatal heart regeneration following apical resection.</a> Stem cell reports. 3, 1 (2014).</li><li>Andersen, D. C., Jensen, C. H., Sheikh, S. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Response+to+Sadek+et+al.+and+Kotlikoff+et+al.">Response to Sadek et al. and Kotlikoff et al.</a> Stem cell reports. 3, 3-4 (2014).</li><li>Phifer, C. B., Terry, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+hypothermia+for+general+anesthesia+in+preweanling+rodents.">Use of hypothermia for general anesthesia in preweanling rodents.</a> Physiol Behav. 38, 887-890 (1986).</li><li>Laflamme, M. A., Murry, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regenerating+the+heart.">Regenerating the heart.</a> Nat Biotechnol. 23, 845-856 (2005).</li><li>Laflamme, M. A., Murry, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+regeneration.">Heart regeneration.</a> Nature. , 326-335 (2011).</li><li>Jesty, S. 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本文的出版费用由精细的科学工具的礼物，侯健博士进行了赞助。

Cardiac regeneration shows potential for the treatment and prevention of heart failure1, 2. Animal models are indispensable and play a critical role in understanding how cardiac regeneration occurs3-6. Many amphibians and fish regenerate heart tissue in response to injury, providing insight into our understanding of human cardiovascular disease13, 14. In terms of evolution, however, the pathophysiology should be more conserved between a mouse model and humans. Heart regeneration in mammal...

Prolonged human life span leads to various aging- and lifestyle-related diseases, including heart failure, a leading cause of mortality. However, without replacement of lost or dysfunctional cardiac muscle cells, current therapeutics can only transiently improve cardiac function1, 2. Thus, it is necessary to discover and develop innovative strategies for cardiac regeneration and repair. The adult mammalian heart has limited regenerative potential. Studies from lower vertebrates, such as urodele amphibians and teleost fish, have provided unprecedented insights into the molecular and cellular mechanisms underlying heart regeneration3, 4. Recently, a neonatal mouse model of heart regeneration has emerged that might enable identification and characterization of more evolutionarily conserved pathophysiological events required for human heart regeneration5. 
Apical resection refers to the surgical removal of left ventricular apex. This procedure is restricted to 1- to 7-day-old (P1 to P7) mice due to its high lethality in older mice6. The cardiac regeneration process in neonatal mice after apical resection is expected to be as follows: (I) rapid and effective formation of a hematoma to seal the apex and prevent exsanguination; (II) cardiomyocyte regeneration and restoration of systolic function5, 7. Recent work has stimulated debate on the significance and efficiency of this model8-11. Thus, it is important to present the apical resection clearly and in detail. To this end, this protocol vividly and specifically describes a video of how I did apical resection based on a previous protocol6. 
Understanding the molecular mechanisms underlying cardiac regeneration is of importance for treatment of heart disease characterized by loss and/or injured cardiomyocytes, such as heart failure1, 2. Given the current and promising progress of apical resection in the research of cardiac regeneration, this study could promote the use of this technique and its uses in cardiac regeneration research.

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apical resection mouse model to study early mammalian heart regeneration

心脑血管疾病困扰着整个世界，由于密集的生活方式的改变。心脏再生持有修复和恢复因受伤和疾病失去了心肌巨大潜力。相反，某些低等脊椎动物的强劲心脏再生，成年哺乳动物心脏通常显示为心脏的再生和修复能力最低。然而，最近的研究已经引起了相当大的科学兴趣地注意到，产后天之间1〜7（P1到P7），新生小鼠心脏保留显著再生潜能根尖切除术（ 即 ，手术截肢和左心室心尖曝光）后的发现。超过这一发现一个主要的争论可能是由于不同的手术相关的程序中的努力来复制或扩大在此重要的发现使用。这些指令动态地呈现材料和方法根尖切除的小鼠模型。其显着的步骤该啮齿动物surviva的升手术涉及低温麻醉，开胸，心脏心室心尖手术截肢，缝合和老鼠的恢复。描述可以扩大根尖切除的小鼠模型的心血管研究的应用程序的方法。

乳鼠被安乐死1，2，和21天后根尖切除术，并收集了H＆E和马尾松的三色染色他们的心。蓝色在马松三色染色表示心外膜细胞外基质5的沉积。与成功的根尖切除，血块被有效地形成，以密封的LV之一天后根尖切除， 如图1A。血凝块和早期心脏纤维化的逐渐再吸收观察，并代之以心肌组织发生直到心肌完全再生发生21天根尖切除后（图1B 和C）。形态学分?...

Watch this Scientific Journal Video about Apical Resection Mouse Model to Study Early Mammalian Heart Regeneration at JoVE.com

Apical Resection Mouse Model to Study Early Mammalian Heart Regeneration

A step-by-step video protocol of apical resection is demonstrated in this study. Apical resection is a recently highlighted surgical approach in mammalian heart regeneration research. This study may promote the application of apical resection as a standard methodology in research into the mechanism underlying heart regeneration.

根尖切除小鼠模型来研究早期哺乳动物心脏再生

Cardiovascular disease plagues the whole world due to intensive lifestyle changes. Heart regeneration holds great promise for repairing and restoring ...

apical-resection-mouse-model-to-study-early-mammalian-heart

Research

JoVE Journal

Medicine

11.2K 次观看.  National Institutes of Health. A step-by-step video protocol of apical resection is demonstrated in this study. Apical resection is a recently highlighted surgical approach in mammalian heart regeneration research. This study may promote the application of apical resection as a standard methodology in research into the mechanism underlying heart regeneration.

视频: Apical Resection Mouse Model to Study Early Mammalian Heart Regeneration

Transplantation of Neonatal Mouse Cardiac Macrophages into Adult Mice

In an injured neonatal myocardium, macrophages facilitate cardiomyocyte proliferation and angiogenesis and promote heart regeneration. The present study reveals that transplantation of neonatal cardiac macrophages recruited by injury promotes adult heart regeneration after myocardial infarction with improvement of cardiac function and cardiomyocyte proliferation. The results indicate that neonatal cardiac macrophage transplantation could be a promising strategy for cardiac injury treatment. Here, we provide the technical details, including the isolation of neonatal cardiac macrophages from apical resection-injured neonatal mouse hearts, the transplantation of macrophages into myocardial-infarcted adult mice, and the estimation of heart regeneration after a macrophage graft.

We provide a protocol for neonatal cardiac macrophage separation and transplantation into an adult mouse heart, which could be a promising way to promote cardiac repair.

将新生儿小鼠心脏巨噬细胞移植到成年小鼠体内

In an injured neonatal myocardium, macrophages facilitate cardiomyocyte proliferation and angiogenesis and promote heart regeneration. The present study ...

科研

生物化学

Capturing the Cardiac Injury Response of Targeted Cell Populations via Cleared Heart Three-Dimensional Imaging

Cardiovascular disease outranks all other causes of death and is responsible for a staggering 31% of mortalities worldwide. This disease manifests in cardiac injury, primarily in the form of an acute myocardial infarction. With little resilience following injury, the once healthy cardiac tissue will be replaced by fibrous, non-contractile scar tissue and often be a prelude to heart failure. To identify novel treatment options in regenerative medicine, research has focused on vertebrates with innate regenerative capabilities. One such model organism is the neonatal mouse, which responds to cardiac injury with robust myocardial regeneration. In order to induce an injury in the neonatal mouse that is clinically relevant, we have developed a surgery to occlude the left anterior descending artery (LAD), mirroring a myocardial infarction triggered by atherosclerosis in the human heart. When matched with the technology to track changes both within cardiomyocytes and non-myocyte populations, this model provides us with a platform to identify the mechanisms that guide heart regeneration. Gaining insight into changes in cardiac cell populations following injury once relied heavily on methods such as tissue sectioning and histological examination, which are limited to two-dimensional analysis and often damage the tissue in the process. Moreover, these methods lack the ability to trace changes in cell lineages, instead providing merely a snapshot of the injury response. Here, we describe how technologically advanced methods in lineage tracing models, whole organ clearing, and three-dimensional (3D) whole-mount microscopy can be used to elucidate mechanisms of cardiac repair. With our protocol for neonatal mouse myocardial infarction surgery, tissue clearing, and 3D whole organ imaging, the complex pathways that induce cardiomyocyte proliferation can be unraveled, revealing novel therapeutic targets for cardiac regeneration.

Cardiomyocyte proliferation following injury is a dynamic process that requires a symphony of extracellular cues from non-myocyte cell populations. Utilizing lineage tracing, passive CLARITY, and three-dimensional whole-mount confocal microscopy techniques, we can analyze the influence of a variety of cell types on cardiac repair and regeneration.

通过清除心脏三维成像捕获目标细胞群的心脏损伤反应

Cardiovascular disease outranks all other causes of death and is responsible for a staggering 31% of mortalities worldwide. This disease manifests in ...

发育生物学

Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure.
Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling.
Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

Heart failure is the leading cause of hospitalization and a major cause of mortality. A model of permanent ligation of the left anterior descending coronary artery in mice is applied to investigate ventricular remodelling and cardiac dysfunction post-myocardial infarction. The technique of invasive hemodynamic measurements in mice is presented.

左冠状动脉前降支的小鼠结扎:对心肌梗死后重塑和心衰模型

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It ...

医学

Clonal Analysis of the Neonatal Mouse Heart using Nearest Neighbor Modeling

By replacing lost or dysfunctional myocardium, tissue regeneration is a promising approach to treat heart failure. However, the challenge of detecting bona fide heart regeneration limits the validation of potential regenerative factors. One method to detect new cardiomyocytes is multicolor lineage tracing with clonal analysis. Clonal analysis experiments can be difficult to undertake, because labeling conditions that are too sparse lack sensitivity for rare events such as cardiomyocyte proliferation, and diffuse labeling limits the ability to resolve clones. Presented here is a protocol to undertake clonal analysis of the neonatal mouse heart by using statistical modeling of nearest neighbor distributions to resolve cardiomyocyte clones. This approach enables resolution of clones over a range of labeling conditions and provides a robust analytical approach for quantifying cardiomyocyte proliferation and regeneration. This protocol can be adapted to other tissues and can be broadly used to study tissue regeneration.

Presented here is a protocol for using multicolor lineage tracing and nearest-neighbor modeling to identify clonally derived cardiomyocytes during growth and regeneration in mice. This approach is objective, works across different labeling conditions, and can be adapted to incorporate a variety of image analysis pipelines.

By replacing lost or dysfunctional myocardium, tissue regeneration is a promising approach to treat heart failure. However, the challenge of detecting ...

Myocardial Infarction in Neonatal Mice, A Model of Cardiac Regeneration

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and regeneration, and to define new targets for therapeutics. For decades, models of complete heart regeneration existed in amphibians and fish, but a mammalian counterpart was not available. The recent discovery of a postnatal window during which mice possess regenerative capabilities has led to the establishment of a mammalian model of cardiac regeneration. A surgical model of mammalian cardiac regeneration in the neonatal mouse is presented herein. Briefly, postnatal day 1 (P1) mice are anesthetized by isoflurane and placed on an ice pad to induce hypothermia. After the chest is opened, and the left anterior descending coronary artery (LAD) is visualized, a suture is placed around the LAD to inflict myocardial ischemia in the left ventricle. The surgical procedure takes 10-15 min. Visualizing the coronary artery is crucial for accurate suture placement and reproducibility. Myocardial infarction and cardiac dysfunction are confirmed by triphenyl-tetrazolium chloride (TTC) staining and echocardiography, respectively. Complete regeneration 21 days post myocardial infarction is verified by histology. This protocol can be used to as a tool to elucidate mechanisms of mammalian cardiac regeneration after myocardial infarction.

This protocol describes a highly reproducible model of cardiac regeneration by surgical induction of myocardial infarction in the left ventricle of postnatal day 1 mice. The method involves induction of hypothermic anesthesia and ligation of the left anterior descending coronary artery.

心肌梗死新生小鼠，心肌再生的模型

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and ...

Transplantation of a 3D Bioprinted Patch in a Murine Model of Myocardial Infarction

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ligation is a challenging procedure and has a high mortality rate due to its nature. We developed a method to consistently transplant bioprinted patches of cells and hydrogels onto the epicardium of an infarcted mouse heart to test their regenerative properties in a robust and feasible way. First, a deeply anesthetized mouse is carefully intubated and ventilated. Following left lateral thoracotomy (surgical opening of the chest), the exposed LAD is permanently ligated and the bioprinted patch transplanted onto the epicardium. The mouse quickly recovers from the procedure after chest closure. The advantages of this robust and quick approach include a predicted 28-day mortality rate of up to 30% (lower than the 44% reported by other studies using a similar model of permanent LAD ligation in mice). Moreover, the approach described in this protocol is versatile and could be adapted to test bioprinted patches using different cell types or hydrogels where high numbers of animals are needed to optimally power studies. Overall, we present this as an advantageous approach which may change preclinical testing in future studies for the field of cardiac regeneration and tissue engineering.

This protocol aims to transplant a 3D bioprinted patch onto the epicardium of infarcted mice modeling heart failure. It includes details regarding anesthesia, the surgical chest opening, permanent ligation of the left anterior descending (LAD) coronary artery and application of a bioprinted patch onto the infarcted area of the heart.

心肌梗塞穆林模型中的 3D 生物打印贴片移植

Testing regenerative properties of 3D bioprinted cardiac patches in vivo using murine models of heart failure via permanent left anterior descending (LAD) ...

生物工程

Blood Circuit Reconstruction in an Abdominal Mouse Heart Transplantation Model

The surgical technique of heterotopic abdominal heart transplantation in mice is a standard model for research in transplantation immunology. Here, the established technique for a modified blood circuit reconstruction in a heterotopic abdominal heart transplantation model is presented. This method uses the intrathoracic inferior vena cava (IIVC) instead of the pulmonary artery of the donor heart for the anastomosis to the inferior vena cava of the recipient. It is facilitating and improving success rates for abdominal heart transplantation in mice.

A novel technique for blood circuit reconstruction in a heterotopic abdominal mouse heart transplantation model is demonstrated.

腹部小鼠心脏移植模型中的血液回路重建

The surgical technique of heterotopic abdominal heart transplantation in mice is a standard model for research in transplantation immunology. Here, the ...

A Modified Cuff Technique for Mouse Cervical Heterotopic Heart Transplantation Model

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

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

一种改进的袖带技术用于小鼠颈椎异位心脏移植模型

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

An Apical Resection Model in the Adult Xenopus tropicalis Heart

It is known that in adult mammals, the heart has lost its regenerative capacity, making heart failure one of the leading causes of death worldwide. Previous research has demonstrated the regenerative ability of the heart of the adult Xenopus tropicalis, an anuran amphibian with a diploid genome and a close evolutionary relationship with mammals. Additionally, studies have shown that following ventricular apex resection, the heart can regenerate without scarring in X. tropicalis. Consequently, these previous results suggest that X. tropicalis is an appropriate alternative vertebrate model for the study of adult heart regeneration. A surgical model of cardiac regeneration in the adult X. tropicalis is presented herein. Briefly, the frogs were anesthetized and fixed; then, a small incision was made with iridectomy scissors, penetrating the skin and pericardium. Gentle pressure was applied to the ventricle, and the apex of the ventricle was then cut out with scissors. Cardiac injury and regeneration were confirmed by histology at 7-30 days post resection (dpr). This protocol established an apical resection model in adult X. tropicalis, which&#160;can be employed to elucidate the mechanisms of adult heart regeneration.

An Apical Resection Model in the Adult Xenopus tropicalis Heart

Xenopus tropicalis is an ideal model for regenerative research as many of its organs possess a remarkable regenerative capacity. Here, we present a method for constructing a heart injury model in X. tropicalis via apex resection.

热带非洲爪蟾成人心脏的根尖切除模型

It is known that in adult mammals, the heart has lost its regenerative capacity, making heart failure one of the leading causes of death worldwide. ...

Preparation of a Non-Cardiomyocyte Cell Suspension for Single-Cell RNA Sequencing from a Post-Myocardial Infarction Adult Mouse Heart

Myocardial infarction (MI) is one of the most common cardiovascular diseases, with increasing mortality worldwide. Non-cardiomyocytes account for more than half of the total cardiac cell population, and they contribute to adaptive compensations upon myocardial injury, including inflammatory responses, tissue repair, and scar formation. To study the post-MI cardiac microenvironment, single-cell RNA sequencing (scRNA-seq) is widely used to identify different cardiac cell types and intercellular communications. Among the procedures of scRNA-seq sample preparation, preparing the cell suspension is one of the most critical steps, because the cell viability can affect the quality of the scRNA-seq results. Therefore, we designed an experimental protocol for preparing a non-cardiomyocyte cell suspension from post-MI mouse hearts with an extra focus on improving the cell viability by choosing mild digestive enzymes, controlling the digestion time, and applying fluorescence-activated cell sorting (FACS). Finally, we isolated CD45+ cells from the non-cardiomyocyte cell suspension obtained through this protocol, and then we performed scRNA-seq.

Here, we describe a protocol to isolate a sufficient amount of single non-cardiomyocytes with high viability from a post-myocardial infarction (MI) mouse heart. This can be used for subsequent single-cell sequencing, flow cytometry analysis, and primary cell culture.

制备用于心肌梗死后成年小鼠心脏单细胞RNA测序的非心肌细胞悬液

Myocardial infarction (MI) is one of the most common cardiovascular diseases, with increasing mortality worldwide. Non-cardiomyocytes account for more ...