这项工作是按顺序一个NCCR前沿遗传学试验奖，青少年糖尿病研究基金会的资助41-2009-775和格兰特12-126875从侦探的frieForskningsråd/ Sundhed OG Sygdom资助。作者感谢SPAGNOLI实验室主办的视频拍摄。

该协议旨在扩大从鼠E10.5派生类器官胰腺上皮分离胰腺细胞。 该协议要求的伦理批准用于动物实验。 背胰芽1。解剖从E10.5小鼠胚胎<ol><li>牺牲定时妊娠小鼠胚胎一天（五）10.5，开有一对剪刀的腹部，取出两个子宫角，并放置在10厘米的培养皿中充满了冷磷酸盐缓冲液（PBS）或贝科改良基本培养基（DMEM）中保持在冰上。总的实验从祭祀细胞种植在60-90分钟做是为了防止细胞损伤。 </li><li>子宫分成用小剪刀个别胚胎段。转移一个胚胎为35 mm培养皿用冷PBS和可视化它在解剖显微镜从上面照射下。用解剖镊子取出周围的肌肉，蜕膜和蛋黄SAc和暴露胚胎。将胚胎放回冷DMEM培养基。胚胎可以很容易地使用3毫升塑料移液管/滴管转移。在继续之前隔离每个人胚胎以类似的方式。 </li><li>将胚胎放入干净35毫米培养皿中的PBS。 <ol><li>使用薄钳（0.05毫米宽），除去前肢。轻轻插入钳子的开口分离从脊髓区域的消化道（ 图1）。可选:为了更方便地看到肚子，取出胚胎的上身，下到下面的蛋黄秆心脏和尾部区域。 </li><li>找到胃，肝和肠。使用镊子，隔离从胃到肠的消化道，并将其放置在冷的DMEM在冰上（ 图1）。背胰芽附着背侧，后到胃（ 图1）。 </li><li>隔离在西米每个人胃肠道在继续之前拉尔方式。如果胚胎需要进行基因分型，收集的尾部在夹层的时间，并保持每一个个体胃肠道在不同的井在24孔板上用冰冷的DMEM中。 </li></ol></li><li>将一个胃肠道在一个干净的35毫米培养皿中冷PBS。现在使用的照明从下面的明视场的解剖显微镜下观察并剖析背胰芽。这些条件将优化卷的可视化。使用电解削尖钨针或20 G注射器针头，分离出胰芽用尽可能少的间充质尽可能周围上皮细胞（ 图1）。 <ol><li>传输的分离的芽到含有冷分散酶溶液（1.25毫克/毫升）为2-3分钟的培养皿中。从这点来说，传输可以最方便地与连接到一个口控制的柔性管火焰拉50微升玻璃毛细管进行。备选地，但更多的里失去了芽的SK，使用10微升自动移液器（的Pipetman）用适当的塑料头。 </li><li>在微观控制执行胰芽愿望和弹射。把胰芽早在PBS中。从使用的玻璃毛细管（ 图1）针和温柔的吸间质进一步清理隔离胰芽。 </li><li>当整个间质被删除，在冲洗冷PBS胰芽;在单井每个芽转移到冷的DMEM（60孔迷你托盘装满10微升冷的DMEM）。它不删除的间质中分散酶是重要的，这使得组织很粘。 </li></ol></li></ol> 2，电镀分散细胞与文化<ol><li>来自胚胎的火焰拉玻璃毛细管进60孔迷你托盘装满10微升PBS冲洗锥形井转让解剖上皮细胞。 <ol><li>转移芽成10微升胰蛋白酶0.05％的ND让它在37℃孵育4分钟。通过传送芽成井与10微升DMEM +10％胎牛血清（FCS）的灭活胰蛋白酶。 </li><li>通过皮薄毛细拉带吸管拉马吸离解细胞悬液。避免气泡在这个阶段，而上下吹打以解离的细胞是重要的。胰腺组织体最佳地小群体的5-15细胞开始，因此部分离解，建议（ 图1）。 </li></ol></li><li>普尔从几个胚胎细胞到Eppendorf管中，以尽量减少由于个体差异的处理。稀释细胞悬液冷冻基底膜以1:3的比例。等分的该混合物到96孔板中，8微升/孔，或在用于成像的最佳化的板（见下文）。 </li><li>将培养板在37℃下进行5分钟，使基底膜变厚。填补了井70微升的选择培养基（组织体或球体，看标签莱1和2），并在含5％CO 2和95％空气中于37℃的潮湿环境中留下</li><li>每一个第 4天更换培养基。每日监控的日益胰腺殖民地和成像记录下这一过程。 </li><li>感兴趣的小分子或蛋白质可以被添加到在该阶段的培养基为干扰实验，如先前报道28。 </li></ol> 表1:类器官培养基。 <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td>材料名称</td><td>股票集中度</td><td>在决赛中浓度</td><td>的蓄积量</td></tr><tr><td>青霉素，链霉素</td><td> 100％ </td><td> 1％ </td><td> 50微升</td></tr><tr><td>淘汰赛血清替代（补充） </td><td> 100％ </td><td> 10％ </td><td> 500微升</td></tr><tr><td> 2 - 巯基乙醇</td><td> 14.3 M </TD&gt; <td> 0.1毫米</td><td> 1微升</td></tr><tr><td>佛波酯（PMA） </td><td> 16微米</td><td> 16纳米</td><td> 5微升</td></tr><tr><td> Y-27632（ROCK抑制剂） </td><td> 50毫米</td><td> 10微米</td><td> 1微升</td></tr><tr><td>表皮生长因子</td><td> 50微克/毫升</td><td> 25纳克/毫升</td><td> 2.5微升</td></tr><tr><td>重组人R-脊椎1 </td><td> 250微克/毫升</td><td> 500毫微克/毫升</td><td> 10微升</td></tr><tr><td> - 或 - </td><td></td><td></td><td></td></tr><tr><td>重组小鼠的R-脊椎蛋白1 </td><td> 250微克/毫升</td><td> 500毫微克/毫升</td><td> 10微升</td></tr><tr><td>重组人FGF1（的aFGF） </td><td> 100微克/毫升</td><td> 25微克/毫升</td><td> 1.25微升</td></tr><tr><td>肝素（Liquemin） </td><td> 2500 U / ml的</td><td> 2.5单位/毫升</td><td> 2微升</td></tr><tr><td>推荐binant人类FGF10 </td><td> 100微克/毫升</td><td> 100毫微克/毫升</td><td> 5微升</td></tr><tr><td> DMEM/F-12 </td><td></td><td></td><td> 4,412.25微升</td></tr><tr><td>总</td><td></td><td></td><td> 5,000微升</td></tr></tbody></table> 表2:球体介质。 <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td>材料名称</td><td>股票集中度</td><td>在决赛中浓度</td><td>的蓄积量</td></tr><tr><td>青霉素，链霉素</td><td> 100％ </td><td> 1％ </td><td> 50微升</td></tr><tr><td> B27×50（增刊） </td><td> 100％ </td><td> 10％ </td><td> 100微升</td></tr><tr><td>重组人FGF2（bFGF）的</td><td> 100微克/毫升</td><td> 64纳克/毫升</td><td> 3.2微升</td></tr><tr><td> Y-27632（ROCK抑制剂） </td><td> 50毫米</td><td> 10微米</td><td> 1微升</td></tr><tr><td> DMEM/F-12 </td><td></td><td></td><td> 4845.8微升</td></tr><tr><td>总</td><td></td><td></td><td> 5000微升</td></tr></tbody></table>类器官发展的进展3。成像<ol><li>图片类器官每天或通过时间推移显微镜用荧光延时显微镜。对于时间的推移成像，使用一个XY（Z）自动倒置荧光显微镜。 </li><li>存款小水滴的3μl，以4孔板或玻璃底板装有2-5毫升培养基。图像与10倍的远距离目标。注意:表达荧光示踪剂的转基因小鼠可以使用。电影1所示，例如组织体从的Pdx1，Ngn3的-ER TM-IRES-nGFP +小鼠4初始扩张。核GFP使用户能够跟踪的细胞作为单独的对象，但类似的原理可以应用到带膜荧光追踪细胞如作为MT / MG小鼠29。 </li><li>接种细胞，避免焦点漂移和设置软件控制自动化取1张/小时，3天或以上的在手动定义的位置后，开始时间推移成像3小时。对于每一个位置，获得一个微分干涉对比（DIC）的形象，以及对GFP信号，报告荧光标记物的表达。 </li></ol>组织体4。恢复的组织学<ol><li>放置在96孔板上的冰和除去培养基，用冰冷的PBS代替。这部分解聚基底膜。 </li><li>轻轻地吸出每个单独的组织体，为了不破坏整体架构使用了1000微升末端除去周围的基质胶。将每个类器官，以良好的用冰冷的PBS。置于冰上板。直接固定在基质胶也是可能的。 </li><li>修复类器官15分钟在4％多聚甲醛（PFA），冷冻保存在蔗糖和嵌入在明胶。处理每个类器官为cryosectioning和组织学如前所述（Johansson 等人 ，2007）4。 </li></ol> 5，恢复组织体进行PCR和生物化学<ol><li>放置在96孔板上的冰和除去介质。加入60微升每孔的RNAlater，以稳定和保护细胞的RNA。 </li><li>通过部分地在冰上解聚破坏它在每个孔的机械凝胶。无论是为了不破坏整体架构或者通过用200μl的前端机械地破坏凝胶恢复整个井（用基质胶）用1,000微升尖恢复单个组织体。使用1,000μl吸头的良好的内容转移到一个无RNA酶，无粘性的Eppendorf管放在冰上。 </li><li>用60微升的RNAlater洗井，其余内容添加到相同的离心管中。 </li><li>旋转的管子5分钟，在500〜1000×g离心在4℃下</li><li>去除上清，只留下20-30微升的RNAlater中的管连同粒料。对于生物化学，储存样本尽可能干燥。 </li><li>不要立即冻结在RNAlater样品;在4°CO / N店（允许RNAlater中彻底穿透组织）。该组织可以被储存在-20℃下长期贮存和以后可以对组织破坏和提取少量的RNA的处理。 </li></ol>

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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=Cerebral+organoids+model+human+brain+development+and+microcephaly.">Cerebral organoids model human brain development and microcephaly.</a> Nature. 10, (2013).</li><li>Greggio, 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=Artificial+three-dimensional+niches+deconstruct+pancreas+development+in+vitro.">Artificial three-dimensional niches deconstruct pancreas development in vitro.</a> Development. 140, 4452-4462 (2013).</li><li>Muzumdar, M. D., Tasic, B., Miyamichi, K., Li, L., Luo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+global+double-fluorescent+Cre+reporter+mouse.">A global double-fluorescent Cre reporter mouse.</a> Genesis. 45, 593-605 (2007).</li></ol>

The authors have nothing to disclose.

大规模生产的功能性β细胞在体外仍然无效1。在这个充满挑战的背景下，发育生物学的研究可能有助于破译所必需的功能性β细胞分化的确切信号。此协议允许在体外胚胎胰腺祖细胞的维持，扩展和分化。这包括形成产生胰岛素的β细胞的不共表达其他内分泌激素，有高水平的Pdx1的，表达了亲convertases的成熟胰岛素和有胰岛素处理28。系统内的重要的关键因素是FGF的活...

器官培养提供了桥梁在体内研究和复杂，但具有很强的针对性之间的差距细胞系模型的方便，但近似模拟一个有用的模型。在胰腺的情况下，不存在细胞系完全等价于胰腺祖细胞虽然有转化细胞系模拟内分泌和外分泌细胞。成人全胰腺不能培养;分离的内分泌胰岛可维持数周而不细胞增殖和组织切片可以保持在体外对几个小时5。胚胎胰腺培养已被广泛使用，不仅研究其发展，还探讨上皮-间充质相互作用4,6,7，对图像进行处理8或化学上与它们9干扰。两个器官培养方法主要应用于:第一种是在纤连蛋白包被的板2，它是型转换器中培养胰芽便于您进行成像的目的;第二个选项是文化在气-液界面3,4的最佳形态保留在过滤器上的器官。虽然非常有用，这些方法会导致一定程度的平坦化的;相比于正常发育和起始群体是复杂的，包括所有类型的胰腺细胞和间充质细胞的前体细胞的扩张是非常有限的。 的能力，培养和扩大分散的初级细胞是有价值的研究谱系关系，并发现分离的细胞类型10的固有性质。杉山等 11能保持胰腺祖细胞和内分泌祖细胞是保留了一些功能特点3-5天培养的饲养层。 Pancreatospheres，类似于神经球12和13微球体，已经扩大，从成人胰岛细胞和导管细胞虽然祖细胞的性质/干细胞产生这些球体是不明确的。另外，在与生理发育相反，pancreatospheres含有一些神经元14,15。领域也从最近胚胎胰腺祖细胞16,17和再生胰腺18具有良好的祖扩张和随后的分化产生，但未能概括形态。 从分散，通常被定义细胞自组织成微型器官3D模型最近已蓬勃发展，并模拟多个器官如肠道19,20，胃21，肝脏22，前列腺23和气管的开发或成年营业额24。在某些情况下，发育和形态发生分化已扼要重述在三维由ES细胞，因为是光学杯25，小肠26或脑27的情况。 在这里，我们DEScribe一个扩大分离的多能胰腺祖细胞在三维基质胶支架在那里他们可以分化和自我组织的方法。

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Gibco</td>
			<td>15070-063</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>KnockOut Serum replacement (supplement)</td>
			<td>Gibco</td>
			<td>10828-028</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>2-mercaptoethanol</td>
			<td>Sigma Aldrich</td>
			<td>3148-25ML</td>
			<td>Stock keept at 4&#176;C</td>
		</tr>
		<tr>
			<td>Phorbol Myristate Acetate (PMA)</td>
			<td>Calbiotech</td>
			<td>524400-1MG</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>Y-27632 (ROCK inhibitor)</td>
			<td>Sigma Aldrich</td>
			<td>ab120129</td>
			<td>Stock keept at -20&#176;C- Attention! Stability/source is a frequent source of problems</td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Sigma Aldrich</td>
			<td>E9644-2MG</td>
			<td>Stock keept at -80&#176;C</td>
		</tr>
		<tr>
			<td>Recombinant Human R-spondin 1</td>
			<td>R&#38;D</td>
			<td>4645-RS-025/CF</td>
			<td>Stock keept at -80&#176;C</td>
		</tr>
		<tr>
			<td>&#160;- or -&#160;</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Mouse R-spondin 1</td>
			<td>R&#38;D</td>
			<td>3474-RS-050</td>
			<td>Stock keept at -80&#176;C</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Human FGF1 (aFGF)</td>
			<td>R&#38;D</td>
			<td>232-FA-025</td>
			<td>Stock keept at -80&#176;C- do not include to increase beta cell production</td>
		</tr>
		<tr>
			<td>Heparin (Liquemin)</td>
			<td>Drossapharm</td>
			<td></td>
			<td>Stock keept at 4&#176;C</td>
		</tr>
		<tr>
			<td>Recombinant Human FGF10</td>
			<td>R&#38;D</td>
			<td>345-FG-025</td>
			<td>Stock keept at -80&#176;C</td>
		</tr>
		<tr>
			<td>DMEM/F-12</td>
			<td>Gibco</td>
			<td>21331-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>Gibco</td>
			<td>15070-063</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>B27 x50 (supplement)</td>
			<td>Gibco</td>
			<td>17504-044</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>Recombinant Human FGF2 (bFGF)</td>
			<td>R&#38;D</td>
			<td>233-FB-025</td>
			<td>Stock keept at -80&#176;C</td>
		</tr>
		<tr>
			<td>Y-27632 (ROCK inhibitor)</td>
			<td>Sigma Aldrich</td>
			<td>ab120129</td>
			<td>Stock keept at -20&#176;C- Attention! Stability/source is a frequent source of problems</td>
		</tr>
		<tr>
			<td>DMEM/F-12</td>
			<td>Gibco</td>
			<td>21331-020</td>
			<td></td>
		</tr>
		<tr>
			<td>Matrigel</td>
			<td>Corning</td>
			<td>356231</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>Trypsin 0.05%</td>
			<td>Gibco</td>
			<td>25300-054</td>
			<td>Stock keept at 4&#176;C</td>
		</tr>
		<tr>
			<td>RNAlater - RNA stabilizing reagent</td>
			<td>Qiagen</td>
			<td>76104</td>
			<td>Store at room temperature</td>
		</tr>
		<tr>
			<td>Dispase&#160;</td>
			<td>Sigma Aldrich</td>
			<td>D4818-2MG</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>BSA for reconstitution</td>
			<td>Milipore</td>
			<td><a href="http://www.millipore.com/catalogue/item/81-068-3">81-068</a></td>
			<td>For reconstituition of cytokines&#160; - Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>Fetal calf serum (FCS)</td>
			<td>Gibco</td>
			<td>16141079</td>
			<td>Stock keept at -20&#176;C</td>
		</tr>
		<tr>
			<td>60 well MicroWell trays</td>
			<td>Sigma Aldrich</td>
			<td>M0815-100EA</td>
			<td></td>
		</tr>
		<tr>
			<td>4-well plates</td>
			<td>Thermo Scientific</td>
			<td>176740</td>
			<td></td>
		</tr>
		<tr>
			<td>95-well plates F bottom</td>
			<td>Greiner Bio</td>
			<td>6555180</td>
			<td></td>
		</tr>
		<tr>
			<td>Glas bottom plates</td>
			<td>Ibidi</td>
			<td>81158</td>
			<td></td>
		</tr>
		<tr>
			<td>Disposal micropittes</td>
			<td>Blaubrand</td>
			<td>708745</td>
			<td></td>
		</tr>
	</tbody>
</table>

in vitro pancreas organogenesis from dispersed mouse embryonic progenitors

The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the development of protocols to produce pancreatic cells from stem cells 1. The whole embryonic organ can be cultured at multiple stages of development 2-4. These culture methods have been useful to test drugs and to image developmental processes. However the expansion of the organ is very limited and morphogenesis is not faithfully recapitulated since the organ flattens. 
We propose three-dimensional (3D) culture conditions that enable the efficient expansion of dissociated mouse embryonic pancreatic progenitors. By manipulating the composition of the culture medium it is possible to generate either hollow spheres, mainly composed of pancreatic progenitors expanding in their initial state, or, complex organoids which progress to more mature expanding progenitors and differentiate into endocrine, acinar and ductal cells and which spontaneously self-organize to resemble the embryonic pancreas. 
We show here that the in vitro process recapitulates many aspects of natural pancreas development. This culture system is suitable to investigate how cells cooperate to form an organ by reducing its initial complexity to few progenitors. It is a model that reproduces the 3D architecture of the pancreas and that is therefore useful to study morphogenesis, including polarization of epithelial structures and branching. It is also appropriate to assess the response to mechanical cues of the niche such as stiffness and the effects on cell&#180;s tensegrity.

分离并接种于三维基质胶E10.5胰背祖概括胰腺发育。祖细胞可以最容易遵循的荧光记者。在我们的例子中，我们使用了转基因小鼠，表达不激活Neurog3 4（ 图2），在没有他莫昔芬，从而通过的Pdx1启动子（ 的Pdx1，Ngn3的-ER TM-nGFP）（电影1）控制的核GFP蛋白。 与组织体介质中，小簇细胞的初始压实发生在第一个小时。膨胀然后可以由簇在...

Watch this Scientific Journal Video about In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors at JoVE.com

In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

在本协议中所述的三维培养方法概括胰腺发育从胚胎分散小鼠胰腺祖细胞，包括他们的大幅扩张，分化和形态发生成支器官。这种方法适合于成像，利基的功能的干扰和操纵。

体外胰腺器官从分散的小鼠胚胎祖细胞

The pancreas is an essential organ that regulates glucose homeostasis and secretes digestive enzymes. Research on pancreas embryogenesis has led to the ...

in-vitro-pancreas-organogenesis-from-dispersed-mouse-embryonic

Research

JoVE Journal

Biology

In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

13.7K 次观看.  Swiss Institute for Experimental Cancer Research. 在本协议中所述的三维培养方法概括胰腺发育从胚胎分散小鼠胰腺祖细胞，包括他们的大幅扩张，分化和形态发生成支器官。这种方法适合于成像，利基的功能的干扰和操纵。 

视频: In Vitro Pancreas Organogenesis from Dispersed Mouse Embryonic Progenitors

In vitro Differentiation of Mouse Embryonic Stem (mES) Cells Using the Hanging Drop Method

Stem cells have the remarkable potential to develop into many different cell types. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, This promising of science is leading scientists to investigate the possibility of cell-based therapies to treat disease.

When culture in suspension without antidifferentiation factors, embryonic stem cells spontaneously differentiate and form three-dimensional multicellular aggregates. These cell aggregates are called embryoid bodies(EB). Hanging drop culture is a widely used EB formation induction method. The rounded bottom of hanging drop allows the aggregation of ES cells which can provide mES cells a good environment for forming EBs. The number of ES cells aggregatied in a hanging drop can be controlled by varying the number of cells in the initial cell suspension to be hung as a drop from the lid of Petri dish. Using this method we can reproducibly form homogeneous EBs from a predetermined number of ES cells. 

In vitro Differentiation of Mouse Embryonic Stem mES Cells Using the Hanging Drop Method

This video demonstrates how to conduct in vitro differentiation of mouse embryonic stem cells to embryoid bodies using the hanging drop method.

在体外分化的小鼠胚胎干细胞（MES）使用悬滴法

Stem cells have the remarkable potential to develop into many different cell types. When a stem cell divides, each new cell has the potential to either ...

科研

生物学

In vitro Labeling of Human Embryonic Stem Cells for Magnetic Resonance Imaging

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of the predominant imaging modalities to assess the restoration of the injured myocardium. Furthermore, ex-vivo labeling agents, such as iron-oxide nanoparticles, have been employed to track and localize the transplanted stem cells. However, this method does not monitor a fundamental cellular biology property regarding the viability of transplanted cells. It has been known that manganese chloride (MnCl2) enters the cells via voltage-gated calcium (Ca2+) channels when the cells are biologically active, and accumulates intracellularly to generate T1 shortening effect. Therefore, we suggest that manganese-guided MRI can be useful to monitor cell viability after the transplantation of hESC into the myocardium.
In this video, we will show how to label hESC with MnCl2 and how those cells can be clearly seen by using MRI in vitro. At the same time, biological activity of Ca2+-channels will be modulated utilizing both Ca2+-channel agonist and antagonist to evaluate concomitant signal changes.

In this video, we are showing how to label human embryonic stem cells (hESC) with manganese chloride (MnCl2) which can enter cells via voltage-gated calcium channels when the cells are biologically active. Additionally, we show the use of MnCl2 as cellular MRI contrast agent to determine the in vitro viability of hESC.

在人类胚胎干细胞体外培养的标签用于磁共振成像

Human embryonic stem cells (hESC) have demonstrated the ability to restore the injured myocardium. Magnetic resonance imaging (MRI) has emerged as one of ...

Single-cell Suction Recordings from Mouse Cone Photoreceptors

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment are open and allow cations to flow steadily inwards across the membrane, depolarizing the cell. Light exposure triggers the closure of the CNG channels, blocks the inward cation current flow, and thus results in cell hyperpolarization. Based on the polarity of photoreceptors, a suction recording method was developed in 1970s that, unlike the classic patch-clamp technique, does not require penetrating the plasma membrane 1. Drawing the outer segment into a tightly-fitting glass pipette filled with extracellular solution allows recording the current changes in individual cells upon test-flash exposure. However, this well-established "outer-segment-in (OS-in)" suction recording is not suitable for mouse cone recordings, because of the low percentage of cones in the mouse retina (3%) and the difficulties in identifying the cone outer segments. Recently, an inner-segment-in (IS-in) recording configuration was developed to draw the inner segment/nuclear region of the photoreceptor into the recording pipette 2,3. In this video, we will show how to record from individual mouse cone photoresponses using single-cell suction electrode.

We will show how to record flash responses from single mouse cones using a suction electrode.

单从小鼠锥感光细胞吸录音

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment ...

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

活体成像和治疗卵巢癌的原位小鼠模型

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Purification of Progenitors from Skeletal Muscle

Skeletal muscle contains multiple progenitor populations of distinct embryonic origins and developmental potential. Myogenic progenitors, usually residing in a "satellite cell position" between the myofiber plasma membrane and the laminin-rich basement membrane that ensheaths it, are self-renewing cells that are solely committed to the myogenic lineage1,2. We have recently described a second class of vessel associated progenitors that can generate myofibroblasts and white adipocytes, which responds to damage by efficiently entering proliferation and provides trophic support to myogenic cells during tissue regeneration3,4. One of the most trusted assays to determine the developmental and regenerative potential of a given cell population relies on their isolation and transplantation5-7. To this end we have optimized protocols for their purification by flow cytometry from enzymatically dissociated muscle, which we will outline in this article. The populations obtained using this method will contain either myogenic or fibro/adipogenic colony forming cells: no other cell types are capable of expanding in vitro or surviving in vivo delivery. However, when these populations are used immediately after the sort for molecular analysis (e.g qRT-PCR) one must keep in mind that the freshly sorted subsets may contain other contaminant cells that lack the ability of forming colonies or engrafting recipients.

Method for the enzymatic dissociation, surface labeling and purification by flow cytometry of fibro/adipogenic and myogenic progenitors from murine skeletal muscle.

纯化的骨骼肌的先觉者

Skeletal muscle contains multiple progenitor populations of distinct embryonic origins and developmental potential. Myogenic progenitors, usually residing ...

A System for ex vivo Culturing of Embryonic Pancreas

The pancreas controls vital functions of our body, including the production of digestive enzymes and regulation of blood sugar levels1. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatic organogenesis, important gaps persist in our knowledge of early pancreas formation2. A complete understanding of these early events will provide insight into the development of this organ, but also into incurable diseases that target the pancreas, such as diabetes or pancreatic cancer. Finally, this information will generate a blueprint for developing cell-replacement therapies in the context of diabetes.
 During embryogenesis, the pancreas originates from distinct embryonic outgrowths of the dorsal and ventral foregut endoderm at embryonic day (E) 9.5 in the mouse embryo3,4. Both outgrowths evaginate into the surrounding mesenchyme as solid epithelial buds, which undergo proliferation, branching and differentiation to generate a fully mature organ2,5,6. Recent evidences have suggested that growth and differentiation of pancreatic cell lineages, including the insulin-producing &beta;-cells, depends on proper tissue-architecture, epithelial remodeling and cell positioning within the branching pancreatic epithelium7,8. However, how branching morphogenesis occurs and is coordinated with proliferation and differentiation in the pancreas is largely unknown. This is in part due to the fact that current knowledge about these developmental processes has relied almost exclusively on analysis of fixed specimens, while morphogenetic events are highly dynamic.
 Here, we report a method for dissecting and culturing mouse embryonic pancreatic buds ex vivo on glass bottom dishes, which allow direct visualization of the developing pancreas (Figure 1). This culture system is ideally devised for confocal laser scanning microscopy and, in particular, live-cell imaging. Pancreatic explants can be prepared not only from wild-type mouse embryos, but also from genetically engineered mouse strains (e.g. transgenic or knockout), allowing real-time studies of mutant phenotypes. Moreover, this ex vivo culture system is valuable to study the effects of chemical compounds on pancreatic development, enabling to obtain quantitative data about proliferation and growth, elongation, branching, tubulogenesis and differentiation. In conclusion, the development of an ex vivo pancreatic explant culture method combined with high-resolution imaging provides a strong platform for observing morphogenetic and differentiation events as they occur within the developing mouse embryo.

A System for ex vivo Culturing of Embryonic Pancreas

Here, we describe a method for isolation, culture and manipulation of mouse embryonic pancreas. This represents an excellent ex vivo system for studying various aspects of pancreatic development, including morphogenesis, differentiation and growth. Pancreatic bud explants can be cultured for several days and used in a range of different applications, including whole-mount immunofluorescence and live imaging.

一个系统<em&gt;体外</em培养的胚胎胰腺

The pancreas controls vital functions of our body,  including the production of digestive enzymes and regulation of blood sugar  levels1. Although in the ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

诱导多能干细胞来源于小鼠的生成

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

RNA Isolation from Mouse Pancreas: A Ribonuclease-rich Tissue

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge. As a primary function of the pancreas is to aid in digestion, mouse pancreas may contain as much a 75 mg of ribonuclease. We report modifications of standard phenol/guanidine thiocyanate lysis reagent protocols to isolate RNA from mouse pancreas. Guanidine thiocyanate is a strong protein denaturant and will effectively disrupt the activity of ribonuclease under most conditions. However, critical modifications to standard protocols are necessary to successfully isolate RNA from ribonuclease-rich tissues. Key steps include a high lysis reagent to tissue ratio, removal of undigested tissue prior to phase separation and inclusion of a ribonuclease inhibitor to the RNA solution. Using these and other modifications, we routinely isolate RNA with RNA Integrity Number (RIN) greater than 7. The isolated RNA is of suitable quality for routine gene expression analysis. Adaptation of this protocol to isolate RNA from ribonuclease rich tissues besides the pancreas should be readily achievable.

We report a procedure to isolate RNA with high integrity from the ribonuclease rich mouse pancreas.

从小鼠胰腺RNA提取:核糖核酸酶丰富的组织

Isolation of high-quality RNA from ribonuclease-rich tissue such as mouse pancreas presents a challenge.  As a primary function of the pancreas is to aid ...

Protein Isolation from the Developing Embryonic Mouse Heart Valve Region

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis method may not be sufficiently sensitive to detect a protein of interest. To overcome these difficulties, we examined protocols for obtaining protein from adult human cardiac valves and modified these protocols for the developing early embryonic mouse counterparts. In brief, the mouse embryonic aortic valve regions, including the aortic valve and surrounding aortic wall, are collected in the minimal possible volume of a Tris-based lysis buffer with protease inhibitors. If required based on the breeding strategy, embryos are genotyped prior to pooling four embryonic aortic valve regions for homogenization. After homogenization, an SDS-based sample buffer is used to denature the sample for running on an SDS-PAGE gel and subsequent western blot analysis. Although the protein concentration remains too low to quantify using spectrophotometric protein quantification assays and have sample remaining for subsequent analyses, this technique can be used to successfully detect and semi-quantify phosphorylated proteins via western blot from pooled samples of four embryonic day 13.5 mouse aortic valve regions, each of which yields approximately 1 &#956;g of protein. This technique will be of benefit for studying cell signaling pathway activation and protein expression levels during early embryonic mouse valve development.

The analysis of protein expression in young embryonic mouse valves has been hampered by the limited tissue available. This manuscript provides a protocol for preparing protein from developing embryonic mouse valve regions for western blot analysis.

从发展胚胎小鼠心脏瓣膜区蛋白分离

Western blot analysis is a commonly employed technique for detecting and quantifying protein levels. However, for small tissue samples, this analysis ...

Procedure to Evaluate the Efficiency of Flocculants for the Removal of Dispersed Particles from Plant Extracts

Plants are important to humans not only because they provide commodities such as food, feed and raw materials, but increasingly because they can be used as manufacturing platforms for added-value products such as biopharmaceuticals. In both cases, liquid plant extracts may need to be clarified to remove particulates. Optimal clarification reduces the costs of filtration and centrifugation by increasing capacity and longevity. This can be achieved by introducing charged polymers known as flocculants, which cross-link dispersed particles to facilitate solid-liquid separation. There are no mechanistic flocculation models for complex mixtures such as plant extracts so empirical models are used instead. Here a design-of-experiments procedure is described that allows the rapid screening of different flocculants, optimizing the clarification of plant extracts and significantly reducing turbidity. The resulting predictive models allow the identification of robust process conditions and sets of polymers with complementary properties, e.g. effective flocculation in extracts with specific conductivities. The results presented for tobacco leaf extracts can easily be adapted to other plant species or tissues and will thus facilitate the development of more cost-effective downstream processes for commodities and plant-derived pharmaceuticals.

The design-of-experiments procedure presented here allows the evaluation of different flocculants in terms of their ability to aggregate dispersed particles in plant extracts, thus reducing turbidity and the costs of downstream processing.

过程评价絮凝剂的效率的分散粒子的从植物提取物的去除

Plants are important to humans not only because they provide commodities such as food, feed and raw materials, but increasingly because they can be used ...