We thank Kwon laboratory members for helpful discussions. This work was supported by grants from NHLBI/NIH (R01HL111198) and Maryland Stem Cell Research Fund (MSCRF).

所有小鼠均维持在实验室动物护理的认可美国协会（AAALAC）-accredited在约翰·霍普金斯大学动物设施及安置按照指南中列出了实验动物的护理和使用的程序。该机构动物护理和使用委员会（IACUC）批准的所有实验方案。 1.实验准备<ol><li>外套12孔板，用10％胎牛血清（FBS）的磷酸盐缓冲溶液（PBS）中60分钟。 </li><li>除去涂布溶液，并添加200微升无血清培养基（SFM）的。捻盘，以确保媒体的膜覆盖整个表面区域。 </li></ol> 2.外科手术<ol><li>安乐死使用机构的动物护理委员会批准的协议，颈椎脱位，以确保完全安乐死孕鼠。 </li><li>喷雾和清洁鼠标的腹部区域有70％乙醇。保持严格的无菌技术，以避免污染。 </li><li>使用镊子和剪刀，使0.5 平方厘米的切口在肚脐区域。 </li><li>用手指捏住/抢皮肤上方和下方的切口，然后轻轻拉动以相反的方向（头部和尾部）的皮肤。 </li><li>使用镊子和剪刀，使在膜的初始切口在肚脐区域。轻轻地从肚脐至卵巢每侧（2×1.5 cm 2）的切成V字形的膜，从而揭示子宫。 </li><li>使用镊子夹住子宫连接卵巢和剪刀输卵管捏在输卵管卵巢端，从而释放从卵巢子宫。 </li><li>轻轻拉起子宫与镊子输卵管切摆脱用剪刀膀胱区的子宫。 </li><li>进一步向上拉子宫通过用钳子的输卵管，并用剪刀剪下输卵管上的另一侧，从而从m释放子宫乌斯河。 </li><li>子宫转移至50ml管中，并加入20毫升冷无菌PBS的与钙离子和镁离子 。 PBS必须包含在胚胎解剖钙离子和镁离子 。 </li><li>轻轻摇动管10秒以洗涤子宫血。 </li><li>从管转移子宫用镊子并将其放置在10ml的培养皿和对子宫的顶部添加冷PBS 5毫升。 </li><li>与广场立体显微镜下子宫菜。 注意：步骤2.13-2.19需要立体显微镜。 </li><li>使用两对镊子从子宫逐一轻轻打开子宫解剖用的胚胎囊羊水。 <ol><li>使用两对镊子小心地打开羊膜囊包围胚胎，掐国资委一个镊子轻轻地从胚胎中取出，用另一钳剪切和从胚胎释放羊膜囊。如果特定基因型的需要，保持羊膜囊进行基因分型。 </li></ol></li><li>在广场一侧的胚胎，并使用镊子削减1 和第 2 次向后拱到心脏的弓和咽囊（ 图1A&#39;&#39;）之间。 </li><li>轻轻翻转胚胎到另一边，并用钳子切断第一和第二拱后方的弓和咽囊之间的心脏。 </li><li>使用镊子将那仍然是连接1 和第 2 次咽弓的胚胎心脏流出道。取出拱门，目前仍在连接在一起蝴蝶（ 图1B）的形状，从胚胎。 </li><li>使用镊子夹住并从剩余的心脏流出道和肠内胚层释放1日咽弓（ 图1B&#39;标有虚线和*）。 </li><li>使用镊子夹住并从剩余的心脏流出道释放第二咽弓和前肠内胚层（ 图1B&#39;表示与虚线和**）。 </li><li>传输每对单独使用镊子拱门和放置两个拱门的中央指定的很好。板1 和第 2 次咽弓在不同的孔。确保拱在与在步骤1.2中加入介质薄膜接触。至关重要的是，拱门并不包含介质，因为它们需要在此期间，以与井用于附连的表面接触。 </li></ol> 3.孵化和影像<ol><li>孵育拱门镀在12孔板在37℃/ 5％CO 2下2小时为拱附加到孔表面面积。 </li><li>轻轻加入200微升37℃的SFM井里的一侧。确保拱门保持连接，并培育O / N。 </li><li>第二天，在视觉上检查咽弓连接，轻轻地加入200微升37℃SFM下来的边良好。如果仍然拱门未婚和漂浮，轻轻地用吸管取出介质而不删除拱门，直到只有媒体的膜离开。用枪头把拱门井和重复步骤3.1的中间。 </li><li>日常监控;添加〜100-200微升媒体每2天更换任何媒体蒸发。 注：迁移细胞后24-48小时左右出现拱，将增殖和迁移拱在未来5-8天。后36-72小时形成跳动的心肌细胞可以从第二咽弓（ 图2B）中观察到。肌管形成可以从第1次咽弓3-7天附件（ 图2A）后进行观察。 </li></ol>

<ol>
	<li>Kelly, 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=The+second+heart+field.">The second heart field.</a> Curr Top Dev Biol. 100, 33-65 (2012).</li><li>Bruneau, B. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+developmental+genetics+of+congenital+heart+disease.">The developmental genetics of congenital heart disease.</a> Nature. 451, 943-948 (2008).</li><li>Tzahor, E., Evans, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pharyngeal+mesoderm+development+during+embryogenesis:+implications+for+both+heart+and+head+myogenesis.">Pharyngeal mesoderm development during embryogenesis: implications for both heart and head myogenesis.</a> Cardiovasc Res. 91, 196-202 (2011).</li><li>Uosaki, H., 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=Direct+Contact+with+Endoderm-like+Cells+Efficiently+Induces+Cardiac+Progenitors+from+Mouse+and+Human+Pluripotent+Stem+Cells.">Direct Contact with Endoderm-like Cells Efficiently Induces Cardiac Progenitors from Mouse and Human Pluripotent Stem Cells.</a> PLoS One. 7 (10), e46413 (2012).</li><li>Cheng, 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=Fibronectin+mediates+mesendodermal+cell+fate+decisions.">Fibronectin mediates mesendodermal cell fate decisions.</a> Development. 140, 2587-2596 (2013).</li><li>Kwon, C., 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=A+regulatory+pathway+involving+Notch1/beta-catenin/Isl1+determines+cardiac+progenitor+cell+fate.">A regulatory pathway involving Notch1/beta-catenin/Isl1 determines cardiac progenitor cell fate.</a> Nature cell biology. 11, 951-957 (2009).</li><li>Shenje, L. T., 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=Precardiac+deletion+of+Numb+and+Numblike+reveals+renewal+of+cardiac+progenitors.">Precardiac deletion of Numb and Numblike reveals renewal of cardiac progenitors.</a> Elife. 3, e02164 (2014).</li><li>Grevellec, A., Tucker, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+pharyngeal+pouches+and+clefts:+Development,+evolution,+structure+and+derivatives.">The pharyngeal pouches and clefts: Development, evolution, structure and derivatives.</a> Semin Cell Dev Biol. 21, 325-332 (2010).</li><li>Kwon, C., Cordes, K. R., Srivastava, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt/beta-catenin+signaling+acts+at+multiple+developmental+stages+to+promote+mammalian+cardiogenesis.">Wnt/beta-catenin signaling acts at multiple developmental stages to promote mammalian cardiogenesis.</a> Cell Cycle. 7, 3815-3818 (2008).</li><li>Cho, G. S., Fernandez, L., Kwon, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regenerative+medicine+for+the+heart:+perspectives+on+stem-cell+therapy.">Regenerative medicine for the heart: perspectives on stem-cell therapy.</a> Antioxid Redox Signal. 21, 2018-2031 (2014).</li></ol>

The authors have nothing to disclose.

在这段视频中，我们将演示如何隔离和9.5天的小鼠胚胎文化第一和第二咽弓。咽弓是短暂的，分段出现在胚胎发育9，其中含有多能心脏祖细胞，积木胚胎10,11 -in第二拱门和头部肌肉祖细胞在第一拱8时，使心脏的craniolateral侧面凸起。 咽弓的解剖需要先进的小鼠胚胎解剖技能。一旦拱已成功解剖使用这种分步协议，并转移至预包被的孔，即拱连接到所?...

咽中胚层细胞产生的心脏的部分和咽肌肉。在胚胎发育期间，从第二心脏字段多能心脏祖细胞从咽中胚层迁移和填充心脏流出道和右心室，和它们的异常发展密切出生缺陷和出生无缺陷的先天性心脏疾病的主要原因相关相关死亡在人类1-3。最近的研究已经表明，咽中胚层有助于头部肌肉，除了心脏，使得胚层的心颅面发展4的一个关键部分。因此，在发展过程中，包括诱导，增殖，以及头部和心脏祖细胞在咽中胚层分化正在积极调查5-7。 直到最近，它仍然是未知的心脏祖细胞是否发生无覆盖扩张UT分化，部分原因是由于他们的细胞环境信息的缺乏。我们最近的研究表明，咽弓作为微环境的心脏和肌肉祖细胞的更新和可体外培养在几个星期8。该块法提供了一个新颖而独特的机会来研究心颅面祖细胞体外的发展。

<table border="0" cellpadding="0" cellspacing="0">
	<colgroup>
		<col span="4" />
	</colgroup>
	<tbody>
		<tr>
			<td>FBS</td>
			<td>Hyclone</td>
			<td>SH30071.03</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS + Ca2 + Mg2</td>
			<td>Corning</td>
			<td>21-030-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>10cm petri plates</td>
			<td>Fishersci</td>
			<td>FB0875712</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissor</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="2">Dissection forceps</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td colspan="2">Serum Free Media:</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>IMDM</td>
			<td>Cellgro</td>
			<td>15-016-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Ham&#8217;s F12</td>
			<td>Cellgro</td>
			<td>10-080-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>N2-SUPPLEMENT</td>
			<td>Gibco</td>
			<td>17502-048</td>
			<td></td>
		</tr>
		<tr>
			<td>B27-retinoic acid</td>
			<td>Gibco</td>
			<td>12587-010</td>
			<td></td>
		</tr>
		<tr>
			<td>10% BSA (in PBS) &#224; (Invitrogen Cat#. P2489)</td>
			<td>Life Sciences</td>
			<td>P2489</td>
			<td></td>
		</tr>
		<tr>
			<td>100X Glutamine (Gibco Cat.# 25030-081)</td>
			<td>Gibco</td>
			<td>35050-61</td>
			<td></td>
		</tr>
		<tr>
			<td>100X Pen/Strep (Gibco Cat#. 15070-063)</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td></td>
		</tr>
	</tbody>
</table>

ex vivo culture of pharyngeal arches to study heart and muscle progenitors and their niche

发育中的胚胎的中胚层咽有助于头部和心脏肌肉组织的广泛地区。我们已经开发出一种学习的头部和心脏祖细胞发育与咽弓（也称为鳃弓） 离体的新方法。使用这种方法，我们最近描述了第二咽弓包含自我更新心脏祖细胞，并作为一个微环境对祖细胞的小鼠心脏发育过程中扩张。祖细胞分化仍然膨胀和拱内，但很快就成为功能的心肌细胞，因为它们迁移出弓。我们还报道说，第一咽弓包含肌肉祖离开后拱引起肌管。在这里，我们展示了解剖，并从发展中国家小鼠胚胎的第一和第二咽弓体外培养的过程。该方法使一个研究头部和心脏祖/ dev的肌肉elopment，包括心肌细胞和肌管的详细体外形成。

在开发过程中，面部肌肉和心脏祖细胞可以作为他们增殖并从1 和第 2 次咽弓迁移，成为头部和心脏肌肉组织，分别为（ 图1A，A&#39;和A&#39;&#39;）进行跟踪。培养咽弓提供学习心脏和肌肉的发育，详细体外的独特方式。解剖和附件咽弓后，从拱门连接迁移细胞可以在24-48小时的培养中观察到。内的培养肌管形成3天可以从1次咽弓和从第二</...

Watch this Scientific Journal Video about Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche at JoVE.com

Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

Here, we present a protocol to culture pharyngeal arches to study the biology of heart and muscle progenitor cells and their microenvironment.

咽弓的体外培养研究心脏和肌肉祖细胞和自己的优势

The pharyngeal mesoderm of developing embryos contributes to broad regions of head and heart musculature. We have developed a novel method to study head ...

ex-vivo-culture-pharyngeal-arches-to-study-heart-muscle-progenitors

Research

JoVE Journal

Developmental Biology

Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

7.7K 次观看.  Johns Hopkins University School of Medicine. Here, we present a protocol to culture pharyngeal arches to study the biology of heart and muscle progenitor cells and their microenvironment.

视频: Ex Vivo Culture of Pharyngeal Arches to Study Heart and Muscle Progenitors and Their Niche

Using Ex Vivo Upright Droplet Cultures of Whole Fetal Organs to Study Developmental Processes during Mouse Organogenesis

Investigating organogenesis in utero is a technically challenging process in placental mammals due to inaccessibility of reagents to embryos that develop within the uterus. A newly developed ex vivo upright droplet culture method provides an attractive alternative to studies performed in utero. The ex vivo droplet culture provides the ability to examine and manipulate cellular interactions and diverse signaling pathways through use of various blocking and activating compounds; additionally, the effects of various pharmacological reagents on the development of specific organs can be studied without unwanted side effects of systemic drug delivery in utero. As compared to other in vitro systems, the droplet culture not only allows for the ability to study three-dimensional morphogenesis and cell-cell interactions, which cannot be reproduced in mammalian cell lines, but also requires significantly less reagents than other ex vivo and in vitro protocols. This paper demonstrates proper mouse fetal organ dissection and upright droplet culture techniques, followed by whole organ immunofluorescence to demonstrate the effectiveness of the method. The ex vivo droplet culture method allows the formation of organ architecture comparable to what is observed in vivo and can be utilized to study otherwise difficult-to-study processes due to embryonic lethality in in vivo models. As a model application system, a small-molecule inhibitor will be utilized to probe the role of vascularization in testicular morphogenesis. This ex vivo droplet culture method is expandable to other fetal organ systems, such as lung and potentially others, although each organ must be extensively studied to determine any organ-specific modifications to the protocol. This organ culture system provides flexibility in experimentation with fetal organs, and results obtained using this technique will help researchers gain insights into fetal development.

Using Ex Vivo Upright Droplet Cultures of Whole Fetal Organs to Study Developmental Processes during Mouse Organogenesis

The&#160;ex vivo&#160;upright droplet culture is an alternative to current&#160;in vitro&#160;and&#160;in vivo&#160;experimental techniques. This protocol is easy to perform and requires smaller amounts of reagent, while permitting the ability to manipulate and study fetal vascularization, morphogenesis, and organogenesis.

运用<em&gt;离体</em&gt;全胎儿各器官的直立滴文化的过程中鼠标研究器官发育过程

Investigating organogenesis in utero is a technically challenging process in placental mammals due to inaccessibility of reagents to embryos that develop ...

科研

发育生物学

Ex Vivo Culture of Chick Cerebellar Slices and Spatially Targeted Electroporation of Granule Cell Precursors

The cerebellar external granule layer (EGL) is the site of the largest transit amplification in the developing brain, and an excellent model for studying neuronal proliferation and differentiation. In addition, evolutionary modifications of its proliferative capability have been responsible for the dramatic expansion of cerebellar size in the amniotes, making the cerebellum an excellent model for evo-devo studies of the vertebrate brain. The constituent cells of the EGL, cerebellar granule progenitors, also represent a significant cell of origin for medulloblastoma, the most prevalent paediatric neuronal tumour. Following transit amplification, granule precursors migrate radially into the internal granular layer of the cerebellum where they represent the largest neuronal population in the mature mammalian brain. In chick, the peak of EGL proliferation occurs towards the end of the second week of gestation. In order to target genetic modification to this layer at the peak of proliferation, we have developed a method for genetic manipulation through ex vivo electroporation of cerebellum slices from embryonic Day 14 chick embryos. This method recapitulates several important aspects of in vivo granule neuron development and will be useful in generating a thorough understanding of cerebellar granule cell proliferation and differentiation, and thus of cerebellum development, evolution and disease.

Ex Vivo Culture of Chick Cerebellar Slices and Spatially Targeted Electroporation of Granule Cell Precursors

The cerebellar external granule layer is the site of the largest transit amplification in the developing brain. Here, we present a protocol to target genetic modification to this layer at the peak of proliferation using ex vivo electroporation and culture of cerebellar slices from embryonic Day 14 chick embryos.

鸡小脑切片的体外培养和空间上有针对性的颗粒细胞前体电穿孔

The cerebellar external granule layer (EGL) is the site of the largest transit amplification in the developing brain, and an excellent model for studying ...

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing cardiovascular progenitors during development and disease. While a number of factors have been implicated in epicardium-derived cell (EPDC) mobilization, the mechanisms governing their subsequent migration and differentiation are poorly understood. Here, we present in vitro and ex vivo strategies to study EPDC motility and differentiation. First, we describe a method of obtaining primary epicardial cells by outgrowth culture from the embryonic mouse heart. We also introduce a detailed protocol to assess three-dimensional migration of labeled EPDC in an organ culture system. We provide evidence using these techniques that genetic deletion of myocardin-related transcription factors in the epicardium attenuates EPDC migration. This approach serves as a platform to evaluate candidate modifiers of EPDC biology and could be used to develop genetic or chemical screens to identify novel regulators of EPDC mobilization that might be useful for cardiac repair.

Epicardial Outgrowth Culture Assay and Ex Vivo Assessment of Epicardial-derived Cell Migration

Here, we describe methods for isolating primary mouse epicardial cells by an outgrowth culture assay and assessing the functional migration of epicardial-derived cells (EPDC) using an ex vivo heart culture system. These protocols are suitable for identifying genetic and chemical modulators of epicardial epithelial-to-mesenchymal transition (EMT) and motility.

心外膜生长培养测定和<em&gt;离体</em&gt;心外膜源性细胞迁移的评估

A single layer of epicardial cells lines the heart, providing paracrine factors that stimulate cardiomyocyte proliferation and directly contributing ...

Identification Of Erythromyeloid Progenitors And Their Progeny In The Mouse Embryo By Flow Cytometry

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where they act as front line sentinels of infection and tissue damage. While other immune cells are continuously renewed from hematopoietic stem and progenitor cells (HSPC) located in the bone marrow, a lineage of macrophages, known as resident macrophages, have been shown to be self-maintained in tissues without input from bone marrow HSPCs. This lineage is exemplified by microglia in the brain, Kupffer cells in the liver and Langerhans cells in the epidermis among others. The intestinal and colon lamina propria are the only adult tissues devoid of HSPC-independent resident macrophages. Recent investigations have identified that resident macrophages originate from the extra-embryonic yolk sac hematopoiesis from progenitor(s) distinct from fetal hematopoietic stem cells (HSC). Among yolk sac definitive hematopoiesis, erythromyeloid progenitors (EMP) give rise both to erythroid and myeloid cells, in particular resident macrophages. EMP are only generated within the yolk sac between E8.5 and E10.5 days of development and they migrate to the fetal liver as early as circulation is connected, where they expand and differentiate until at least E16.5. Their progeny includes erythrocytes, macrophages, neutrophils and mast cells but only EMP-derived macrophages persist until adulthood in tissues. The transient nature of EMP emergence and the temporal overlap with HSC generation renders the analysis of these progenitors difficult. We have established a tamoxifen-inducible fate mapping protocol based on expression of the macrophage cytokine receptor Csf1r promoter to characterize EMP and EMP-derived cells in vivo by flow cytometry.

While infiltrating macrophages are continuously recruited to adult tissues from circulating precursors, resident macrophages seed their tissue during development, where they are maintained without further input from progenitors. The progenitors for resident macrophages were recently identified. Here, we present methods for the genetic fate mapping of the resident macrophage progenitors.

通过流式细胞术鉴定小鼠胚胎中的红细胞生成素及其后代

Macrophages are professional phagocytes from the innate arm of the immune system. In steady-state, sessile macrophages are found in adult tissues where ...

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced in vivo throughout the rapid developmental period. Multiple processes can be studied including cell proliferation, gene expression, cell migration and morphogenesis. Importantly, the generation of chimeras through transplantations can be easily performed, allowing mosaic labeling and tracking of individual cells under the influence of the host environment. For example, by combining functional gene manipulations of the host embryo (e.g., through morpholino microinjection) and live imaging, the effects of extrinsic, cell nonautonomous signals (provided by the genetically modified environment) on individual transplanted donor cells can be assessed. Here we demonstrate how this approach is used to compare the onset of fluorescent transgene expression as a proxy for the timing of cell fate determination in different genetic host environments.
In this article, we provide the protocol for microinjecting zebrafish embryos to mark donor cells and to cause gene knockdown in host embryos, a description of the transplantation technique used to generate chimeric embryos, and the protocol for preparing and running in vivo time-lapse confocal imaging of multiple embryos. In particular, performing multiposition imaging is crucial when comparing timing of events such as the onset of gene expression. This requires data collection from multiple control and experimental embryos processed simultaneously. Such an approach can easily be extended for studies of extrinsic influences in any organ or tissue of choice accessible to live imaging, provided that transplantations can be targeted easily according to established embryonic fate maps.

In Vivo Imaging of Transgenic Gene Expression in Individual Retinal Progenitors in Chimeric Zebrafish Embryos to Study Cell Nonautonomous Influences

Live tracking of individual WT retinal progenitors in distinct genetic backgrounds allows for the assessment of the contribution of cell non-autonomous signaling during neurogenesis. Here, a combination of gene knockdown, chimera generation via embryo transplantation and in vivo time-lapse confocal imaging was utilized for this purpose.

在嵌合斑马鱼胚胎的个别视网膜祖细胞转基因表达的体内成像来研究细胞非自治的影响

The genetic and technical strengths have made the zebrafish vertebrate a key model organism in which the consequences of gene manipulations can be traced ...

Isolation, Culture, and Differentiation of Bone Marrow Stromal Cells and Osteoclast Progenitors from Mice

Bone marrow stromal cells (BMSCs) constitute a cell population routinely used as a representation of mesenchymal stem cells in vitro. They reside within the bone marrow cavity alongside hematopoietic stem cells (HSCs), which can give rise to red blood cells, immune progenitors, and osteoclasts. Thus, extractions of cell populations from the bone marrow results in a very heterogeneous mix of various cell populations, which can present challenges in experimental design and confound data interpretation. Several isolation and culture techniques have been developed in laboratories in order to obtain more or less homogeneous populations of BMSCs and HSCs invitro. Here, we present two methods for isolation of BMSCs and HSCs from mouse long bones: one method that yields a mixed population of BMSCs and HSCs and one method that attempts to separate the two cell populations based on adherence. Both methods provide cells suitable for osteogenic and adipogenic differentiation experiments as well as functional assays.

In this article, we present methods to isolate and differentiate bone marrow stromal cells and hematopoietic stem cells from mouse long bones. Two different protocols are presented yielding different cell populations suitable for expansion and differentiation into osteoblasts, adipocytes, and osteoclasts.

小鼠骨髓基质细胞与骨破骨祖的分离、培养及分化

Bone marrow stromal cells (BMSCs) constitute a cell population routinely used as a representation of mesenchymal stem cells in vitro. They reside within ...

Application of Chronic Stimulation to Study Contractile Activity-induced Rat Skeletal Muscle Phenotypic Adaptations

Skeletal muscle is a highly adaptable tissue, as its biochemical and physiological properties are greatly altered in response to chronic exercise. To investigate the underlying mechanisms that bring about various muscle adaptations, a number of exercise protocols such as treadmill, wheel running, and swimming exercise have been used in the animal studies. However, these exercise models require a long period of time to achieve muscle adaptations, which may be also regulated by humoral or neurological factors, thus limiting their applications in studying the muscle-specific contraction-induced adaptations. Indirect low frequency stimulation (10 Hz) to induce chronic contractile activity (CCA) has been used as an alternative model for exercise training, as it can successfully lead to muscle mitochondrial adaptations within 7 days, independent of systemic factors. This paper details the surgical techniques required to apply the treatment of CCA to the skeletal muscle of rats, for widespread application in future studies.

This protocol describes the use of the chronic contractile activity model of exercise to observe stimulation-induced skeletal muscle adaptations in the rat hindlimb.

慢性刺激在收缩活动性大鼠骨骼肌表型适应性研究中的应用

Skeletal muscle is a highly adaptable tissue, as its biochemical and physiological properties are greatly altered in response to chronic exercise. To ...

In Vivo Imaging of Muscle-tendon Morphogenesis in Drosophila Pupae

Muscles together with tendons and the skeleton enable animals including humans to move their body parts. Muscle morphogenesis is highly conserved from animals to humans. Therefore, the powerful Drosophila model system can be used to study concepts of muscle-tendon development that can also be applied to human muscle biology. Here, we describe in detail how morphogenesis of the adult muscle-tendon system can be easily imaged in living, developing Drosophila pupae. Hence, the method allows investigating proteins, cells and tissues in their physiological environment. In addition to a step-by-step protocol with helpful tips, we provide a comprehensive overview of fluorescently tagged marker proteins that are suitable for studying the muscle-tendon system. To highlight the versatile applications of the protocol, we show example movies ranging from visualization of long-term morphogenetic events &#8211; occurring on the time scale of hours and days &#8211; to visualization of short-term dynamic processes like muscle twitching occurring on time scale of seconds. Taken together, this protocol should enable the reader to design and perform live-imaging experiments for investigating muscle-tendon morphogenesis in the intact organism.

In Vivo Imaging of Muscle-tendon Morphogenesis in Drosophila Pupae

Here, we present an easy-to-use and versatile method to perform live imaging of developmental processes in general and muscle-tendon morphogenesis in particular in living Drosophila pupae.

在体内果蝇蛹肌肌腱形态的影像学研究

Muscles together with tendons and the skeleton enable animals including humans to move their body parts. Muscle morphogenesis is highly conserved from ...

Generation of First Heart Field-like Cardiac Progenitors and Ventricular-like Cardiomyocytes from Human Pluripotent Stem Cells

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is a pre-requisite for cell-based cardiac therapies and disease modeling. We have recently shown that Id genes are both necessary and sufficient to specify first heart field progenitors during vertebrate development. This differentiation protocol leverages these findings and uses Id1 overexpression in combination with Activin A as potent specifying cues to produce first heart field-like (FHF-L) progenitors. Importantly, resulting progenitors efficiently differentiate (~70&#8211;90%) into ventricular-like cardiomyocytes. Here we describe a detailed method to 1) generate Id1-overexpressing hPSCs and 2) differentiate scalable quantities of cryopreservable FHF-L progenitors and ventricular-like cardiomyocytes.

Here we describe a scalable method, using a simple combination of Activin A and lentivirus-mediated Id1-overexpression, to generate first heart field-like cardiac progenitors and ventricular-like cardiomyocytes from human pluripotent stem cells.

人多潜能干细胞第一心场样心脏祖细胞和心室样细胞的生成

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is ...

Ex Vivo Perfusion of the Rodent Placenta

The placenta is a key organ during pregnancy that serves as a barrier to fetal xenobiotic exposure and mediates the exchange of nutrients for waste. An assay is described here to perfuse an isolated rat placenta and evaluate the maternal-to-fetal translocation of xenobiotics ex vivo. In addition, the evaluation of physiological processes such as fluid flow to the fetus and placental metabolism may be conducted with this methodology. This technique is suitable for evaluating maternal-to-fetal kinetics of pharmaceutical candidates or environmental contaminants. In contrast to current alternative approaches, this methodology allows the evaluation of the isolated maternal-fetal vasculature, with the systemic neural or immune involvement removed, allowing any observed changes in physiological function to be attributable to local factors within the isolated tissue.

Here is presented a protocol of ex vivo maternal-fetal vascular perfusion to enable the administration of a test article into maternal vasculature and to evaluate placental transfer of xenobiotic particles or pharmacological agents in addition to alterations in placental physiology.

啮齿类动物胎盘的体外灌注

The placenta is a key organ during pregnancy that serves as a barrier to fetal xenobiotic exposure and mediates the exchange of nutrients for waste. An ...