Authors would like to thank Catherine Solioz for her skillful assistance.

1. BCM准备<ol><li>从获得当地的屠户尽可能新鲜的猪的下颌骨。将下颚骨到坚硬的表面，并释放一个全厚皮瓣特别注意不要留下任何软组织或骨膜附着于骨。在清洁的环境，而不需要的流罩下工作的工作。 </li><li>一旦全厚瓣被释放，使用骨刮板从颊侧收获了碎骨片。请注意，骨刮板必须锐利。处理坚决骨刮板和长运动收集骨头。弃骨碎片越小1毫米。 <ol><li>维持天然骨片，直接将骨碎片直径10厘米与补充有1％抗生素和抗真菌剂不能让它们变干的Dulbecco氏改良的Eagle氏培养基（DMEM）的塑料盘中。 </li><li>为了评价热加工的影响，受骨芯片在80℃巴氏灭菌30分钟或高压釜20分钟，121℃。 </li><li>为了评价脱矿质的影响，摇骨碎片在1M HCL为4-6小时，在4℃，并用培养基反复洗涤直到pH为中性。 </li></ol></li><li>总共5克每10ml新鲜的DMEM补充有1％抗生素和抗真菌剂的骨片的放置到一个新的塑料盘。 </li><li>将塑料皿在湿润气氛中，在37℃下放置24小时。然后，收获BCM。离心机BCM的在200×g离心10分钟以除去碎片，将其过滤灭菌（0.2纳米），并保持等份冷冻在-80℃。 </li><li>在即将使用前解冻BCM股票和避免冷冻和解冻的重复循环。 </li><li>为指示的实验中，浸泡胶原膜与BCM或无血清培养基进行1小时，在室温。用PBS洗涤大力膜并将它们放入96孔板。湿膜用细胞接种。 </li><li> BCM的制备方法概述于图1中 。 </LI&gt; </ol>基于间充质细胞生物测定2 <ol><li>种子的人类间充质细胞（例如成骨细胞，牙龈和牙周膜细胞）到12孔板用30,000个细胞/ cm 2的浓度。种子细胞用生长培养基由DMEM，10％胎牛血清和抗生素。让细胞附着到板O / N。 </li><li>弃去培养液，用预温的PBS在37℃下洗涤细胞。通过加入预热的无血清培养基中有和没有20％BCM刺激细胞。将细胞在湿润气氛中，在37℃下放置24小时。 </li><li>弃去培养液，冲洗细胞与预热PBS，并根据您的首选协议提取RNA。 </li><li>调节RNA的浓度，以使每个样品中的RNA的量相同。制备的cDNA和执行定量RT-PCR分析，使用表1所示的引物的选择的基因。 注：这是每一个组件的稀释液：2X SYBR绿，20X引着，20X引反向，5倍无菌水DD，5倍的cDNA。的定量RT-PCR在95℃15秒40个循环和60℃1分钟进行。 </li><li> CT GAPDH和Δ（ΔCT）是ΔCT刺激 - - ΔCT控制通过标准化来使用Δ（ΔCT）方法，其中ΔCT是CT目标看家基因GAPDH计算相对表达水平。 </li><li>这种质量控制后，添加BCM到培养基来刺激所有类型的细胞，包括间充质细胞，造血细胞或内皮细胞。 </li></ol>

<ol>
	<li>Buser, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+Stability+of+Early+Implant+Placement+with+Contour+Augmentation.">Long-term Stability of Early Implant Placement with Contour Augmentation.</a> Journal of dental research. , (2013).</li><li>Chiapasco, M., Casentini, P., Bone Zaniboni, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=augmentation+procedures+in+implant+dentistry.">augmentation procedures in implant dentistry.</a> The International journal of oral &amp; maxillofacial implants. 24 Suppl. , 237-259 (2009).</li><li>Giannoudis, P. V., Dinopoulos, H., Bone Tsiridis, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=substitutes:+an+update.+Injury.">substitutes: an update. Injury.</a> 36, Suppl 3. S20-S27. , (2005).</li><li>Jensen, S. S., Broggini, N., Hjorting-Hansen, E., Schenk, R., Bone Buser, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=healing+and+graft+resorption+of+autograft,+anorganic+bovine+bone+and+beta-tricalcium+phosphate.+A+histologic+and+histomorphometric+study+in+the+mandibles+of+minipigs.">healing and graft resorption of autograft, anorganic bovine bone and beta-tricalcium phosphate. A histologic and histomorphometric study in the mandibles of minipigs.</a> Clinical oral implants research. 17, 237-243 (2006).</li><li>Jensen, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+a+novel+biphasic+calcium+phosphate+in+standardized+bone+defects:+a+histologic+and+histomorphometric+study+in+the+mandibles+of+minipigs.">Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs.</a> Clinical oral implants research. 18, 752-760 (2007).</li><li>Grabowski, G., Bone Cornett, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=graft+and+bone+graft+substitutes+in+spine+surgery:+current+concepts+and+controversies.">graft and bone graft substitutes in spine surgery: current concepts and controversies.</a> The Journal of the American Academy of Orthopaedic Surgeons. 21, 51-60 (2013).</li><li>Khan, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biology+of+bone+grafting.">The biology of bone grafting.</a> The Journal of the American Academy of Orthopaedic Surgeons. 13, 77-86 (2005).</li><li>Bohr, H., Ravn, H. O., Werner, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+osteogenic+effect+of+bone+transplants+in+rabbits.+The+Journal+of+bone+and+joint+surgery.">The osteogenic effect of bone transplants in rabbits. The Journal of bone and joint surgery.</a> British. 50, 866-873 (1968).</li><li>Bone Urist, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=formation+by+autoinduction.">formation by autoinduction.</a> Science. 150, 893-899 (1965).</li><li>Caball&#233;-Serrano, J. D., Buser, D., Gruber, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+porcine+bone+conditioned+medium.">Proteomic analysis of porcine bone conditioned medium.</a> The International journal of oral &amp; maxillofacial implants. , (2014).</li><li>Peng, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone-Conditioned+Medium+Inhibits+Osteogenic+and+Adipogenic+Differentiation+of+Mesenchymal+Cells+In+Vitro.">Bone-Conditioned Medium Inhibits Osteogenic and Adipogenic Differentiation of Mesenchymal Cells In Vitro.</a> Clinical implant dentistry and related research. , (2014).</li><li>Brolese, E., Buser, D., Kuchler, U., Schaller, B., Gruber, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+bone+chips+release+of+sclerostin+and+FGF-23+into+the+culture+medium:+an+in+vitro+pilot+study.">Human bone chips release of sclerostin and FGF-23 into the culture medium: an in vitro pilot study.</a> Clinical oral implants research. , (2014).</li><li>Caball&#233;-Serrano, J., Bosshardt, D. D., Gargallo-Albiol, J., Buser, D., Bone Gruber, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=conditioned+medium+enhances+osteoclastogenesis+in+murine+bone+marrow+cultures.+Clin+Oral+Impl+Res;+in.">conditioned medium enhances osteoclastogenesis in murine bone marrow cultures. Clin Oral Impl Res; in.</a> Int J Oral Maxillofac Surg. , (2015).</li><li>Zimmermann, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone-conditioned+medium+changes+gene+expression+in+bone-derived+fibroblasts).">Bone-conditioned medium changes gene expression in bone-derived fibroblasts).</a> IJOMI accepted. , (2014).</li><li>Fulzele, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myelopoiesis+is+regulated+by+osteocytes+through+Gsalpha-dependent+signaling.">Myelopoiesis is regulated by osteocytes through Gsalpha-dependent signaling.</a> Blood. 121, 930-939 (2013).</li><li>Becerra, J., Andrades, J. A., Ertl, D. C., Sorgente, N., Nimni, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Demineralized+bone+matrix+mediates+differentiation+of+bone+marrow+stromal+cells+in+vitro:+effect+of+age+of+cell+donor.">Demineralized bone matrix mediates differentiation of bone marrow stromal cells in vitro: effect of age of cell donor.</a> Journal of. 11, 1703-1714 (1996).</li><li>Kupcova Skalnikova, ., H, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+techniques+for+characterisation+of+mesenchymal+stem+cell+secretome.">Proteomic techniques for characterisation of mesenchymal stem cell secretome.</a> Biochimie. , (2013).</li><li>Romanello, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Osteoblastic+cell+secretome:+A+novel+role+for+progranulin+during+risedronate+treatment.">Osteoblastic cell secretome: A novel role for progranulin during risedronate treatment.</a> , (2013).</li><li>Schuldt Filho, ., G, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conditioned+medium+of+demineralized+bone+matrix+activates+TGF-&#946;+signaling+pathways+in+mesenchymal+cells+in+vitro.">Conditioned medium of demineralized bone matrix activates TGF-&#946; signaling pathways in mesenchymal cells in vitro.</a> J Cranio Maxill Surg. , (2015).</li><li>Buser, D., Chen, S. T., Weber, H. P., Belser, U. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+implant+placement+following+single-tooth+extraction+in+the+esthetic+zone:+biologic+rationale+and+surgical+procedures).">Early implant placement following single-tooth extraction in the esthetic zone: biologic rationale and surgical procedures).</a> The International journal of periodontics &amp; restorative dentistry. 28, 441-451 (2008).</li><li>Stoecklin-Wasmer, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Absorbable+collagen+membranes+for+periodontal+regeneration:+a+systematic+review.">Absorbable collagen membranes for periodontal regeneration: a systematic review.</a> Journal of dental research. 92, 773-781 (2013).</li></ol>

作者什么都没有透露。霍尔迪卡巴耶 - 塞拉诺获得奖学金的牙科研究和教育，巴塞尔，瑞士的基金会。

骨条件培养基反映骨移植物的过程中的骨再生的早期阶段的释放活性。这里描述的协议可以适于研究不同类型参与骨再生的细胞的反应。此外，该协议可以用于制备从加工骨或骨填充剂的条件培养基。该方法很容易执行，并依靠一个简单的概念：从各种天然和加工骨释放的因素。如何理解BCM影响间充质细胞可以帮助更多地了解移植整合和自体骨的性质。基于这种理念，我们已经积累了BCM从本土<sup...

自体骨被广泛用于桥接发生作为结果畸形，切除手术，重建手术创伤，和之前植入物放置1,2-缺陷。了解骨移植物是如何支持巩固移植的过程中，生物的原则是不理解为什么自体被认为是在重建手术的金标准唯一的关键，这也是仿生骨代用品3的改进设计。尽管如此，移植合并是更快地与自体骨相比，骨替代4,5。因此，当务之急是揭示，使自体骨以便有效地支持骨再生的分子和细胞机制。 还有被认为支持整合过程6,7自体移植三种教科书的特点。首先，自体骨骨传导是，新成立的骨生长提供指导入缺陷。其次，自体骨的成骨，这意味着它包含间充质细胞，能分化成成骨细胞8。第三，自体骨是骨诱导性的像埋葬在基质骨形态发生蛋白的生长因子可以发起软骨内或甚至膜内骨形成9的过程。还有另外一个方面：新鲜制备的骨碎片保持基于在体外观察与“骨条件培养基”10-15旁分泌功能。还骨髓细胞生成的影响应该提到16。与之类似的术语“脱钙骨基质条件培养基”已经创造于1996年，支持骨旁分泌功能的整体概念，即使是由脱盐处理17。对于我们而言，BCM可以从新鲜的猪准备下颌骨10,11。 BCM的蛋白质组学分析显示的成分复杂，包括生长事实口服补液盐和细胞外基质10的成分，也延长对整骨18,19的蛋白酶现有的知识。因此，BCM应该反映骨移植体外的各种修改的发布活动。 当间质细胞，例如来自骨片或口腔软组织中分离，暴露于BCM？ 在体外会发生什么，BCM降低了成骨和脂肪细胞分化，并引发IL11表达11的强劲增长。基因组范围的微阵列显示多个基因被差异表达的间充质细胞响应于BCM。在这些基因中有肾上腺髓质素（ADM），IL11，IL33，NADPH氧化酶4（NOX4），蛋白聚糖4（PRG4或润滑素）和五聚环蛋白3（PTX3）15。从高压灭菌骨碎片得到的BCM未能改变各基因14的表达。从骨片的巴氏杀菌经历和冻结BCM能改变基因表达14。脱钙骨基质（DBM-CM）的还条件培养基改变TGF-β调控的基因20的表达。有趣的是，用于从周围的软组织21,22屏蔽骨片胶原阻挡隔膜，吸附BCM的，负责的基因表达的变化23的那些部分。 BCM研究可以扩展到参与骨再生等骨吸收的破骨细胞和内皮细胞的其它细胞类型，仅举几例。总体而言，累积体外数据提供用于临床前研究的设计的科学依据。 本协议是两方面：首先，它显示了如何准备BCM。其次，它显示了如何基于骨髓间质细胞在体外测试其生物活性。

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Pig Mandibles</td>
			<td>Local bucher</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Bone Scraper</td>
			<td>Hu-Friedy</td>
			<td>PPBUSE2/36</td>
			<td></td>
		</tr>
		<tr>
			<td>Antibiotics &#38; Antimicotics</td>
			<td>All life Technologies</td>
			<td>15240-062</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagen Membranes (Bio-Gide)</td>
			<td>Geistlich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Calf Serum</td>
			<td>Invitrogen Corporation</td>
			<td align="right">16030074</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Invitrogen Corporation</td>
			<td>21885-025</td>
			<td></td>
		</tr>
		<tr>
			<td> 
			High Pure RNA Isolation Kit</td>
			<td>Roche</td>
			<td align="right">11828665001</td>
			<td></td>
		</tr>
		<tr>
			<td>Transcriptor First Strand cDNA Synthesis Kit</td>
			<td>Roche</td>
			<td align="right">4379012001</td>
			<td></td>
		</tr>
		<tr>
			<td>Primers</td>
			<td>Microsynth</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>SYBR Green (for Q-RT-PCR)</td>
			<td>Roche</td>
			<td align="right">4673484001</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Roche</td>
			<td align="right">11666789001</td>
			<td></td>
		</tr>
	</tbody>
</table>

bone conditioned medium: preparation and bioassay

自体骨移植被广泛应用于口腔颌面外科，骨科，骨伤。自体骨移植不仅取代失去的骨头，它们还支持骨再生的复杂过程。自体移植的这种有利的行为归因于三个特点：骨传导性，osteogenicity，和骨诱导性。然而，还有另外一个方面：骨移植物释放分子，包括生长因子，它可以靶向参与骨再生的间充质细胞的无数。骨移植物的旁分泌性能还可以通过使用骨条件培养基（BCM）来进行体外研究。在这里，我们提出了一个协议就如何从本地猪皮质骨骨准备条件培养基和骨头进行热加工或脱矿。细胞可以直接暴露于BCM或接种于生物材料，如胶原膜，与前面的BCM湿透。我们举例说明体外 bioassaYS上的TGF-β调节基因表达的间质细胞。所提出的协议应该鼓励进一步揭示骨移植的旁分泌影响骨再生期间和重建手术的广阔领域打开了转化型研究的路径。

骨条件培养基从新鲜猪碎骨片制成。该方法的一般概述，制备BCM和用于与BCM组合的生物材料示于图1和图2分别。在BCM制备，重要的是要获得大的骨片，长动作短的运动或非常小的骨片可以影响最终BCM的质量。霉素，PTX3，IL11，IL33，NOX4和PRG4（ 图3）：BCM的质量可以通过分析BCM靶基因的基因表达的控制。 ADM和PTX3都下调至0.4倍，IL11，IL33，NOX4和PRG4可以是上调至200?...

Watch this Scientific Journal Video about Bone Conditioned Medium: Preparation and Bioassay at JoVE.com

Bone Conditioned Medium: Preparation and Bioassay

我们在这里描述了如何准备骨条件培养基（BCM）和体外测试其活性。

骨条件培养基的制备和生物测定

Autologous bone grafts are widely used in oral and maxillofacial surgery, orthopedics, and traumatology. Autologous bone grafts not only replace missing ...

bone-conditioned-medium-preparation-and-bioassay

Research

JoVE Journal

Biology

11.0K 次观看.  School of Dental Medicine, University of Bern. 我们在这里描述了如何准备骨条件培养基（BCM）和体外测试其活性。 

视频: Bone Conditioned Medium: Preparation and Bioassay

Maintaining Wolbachia in Cell-free Medium

In this video protocol, procedures are demonstrated to (1) purify Wolbachia symbionts out of cultured mosquito cells, (2) use a fluorescent assay to ascertain the viability of the purified Wolbachia and (3) maintain the now extracellular Wolbachia in cell-free medium.  Purified Wolbachia remain alive in the extracellular phase but do not replicate until re-inoculated into eukaryotic cells.  Extracellular Wolbachia purified in this manner will remain viable for at least a week at room temperature, and possibly longer.  Purified Wolbachia are suitable for micro-injection, DNA extraction and other applications. 


This video describes a method for purifying Wolbachia pipientis from an Anopheles gambiae cell line and then culturing the endosymbiont in cell-free medium. An assay for viability of the bacterium is demonstrated.

维持细胞培养基的Wolbachia

In this video protocol, procedures are demonstrated to (1) purify Wolbachia symbionts out of cultured mosquito cells, (2) use a fluorescent assay to ...

科研

生物学

The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser MXcell  electroporation system and Gene Pulser  electroporation buffer were specifically developed to transfect nucleic acids into mammalian cells and difficult-to-transfect cells, such as primary and stem cells.This video demonstrates how to establish primary hematopoietic cell cultures from murine bone marrow, and then prepare them for electroporation in the MXcell system. We begin by isolating femur and tibia. Bone marrow from both femur and tibia are then harvested and cultures are established. Cultured bone marrow cells are then transfected and analyzed.

This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation system.

主电穿孔的小鼠骨髓造血细胞培养制备

It is becoming increasingly apparent that electroporation is the most effective way to introduce plasmid DNA or siRNA into primary cells. The Gene Pulser ...

Undecalcified Bone Preparation for Histology, Histomorphometry and Fluorochrome Analysis

Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides vital information on bone turnover or bone formation and resorption. This has tremendous importance in a variety of clinical and research applications. It yields beautiful images1 and allows for techniques such as fluorochrome assessment and histomorphometry2. Fluorochrome analysis is a technique where fluorescent dyes that bind to calcium are injected at a particular time point, which allows for quantification of the amount of mineralisation at that given time. Histomorphometry is a process of bone quantification at the microscopic level. 
Performing undecalcified bone histology is technically challenging, particularly with large size specimens. It requires variations in technique from those used in standard paraffin embedded histology. This video illustrates the process of producing good quality sections and demonstrates the technical difficulties and methods with which to overcome them. Specimen preparation, fixation and processing are achieved with a manner similar to other soft tissues, however due to the density and lower permeability of bone considerably longer fixation and processing times are required, often taking several weeks. Embedding is achieved using a supporting medium with similar or equal hardness and density to the bone such as methacrylate- based resins, but unlike paraffin infiltration and embedding, this is an irreversible step. Sectioning can be achieved by grinding which produces a thicker section, which is optimal for studies such as fluorochrome analysis. This is best achieved using a diamond blade on a macrotome. Alternatively, thinner sections can be produced for light microscopy and this is achieved using a sledge microtome with a very sharp blade. The sledge microtome provides the additional strength and stability required for large, hard blocks. Resin embedded sections can be stained with a variety of stains, which are demonstrated.

Undecalcified bone histology provides important information for a variety of clinical and research applications. It is technically challenging, particularly with large size specimens. This video illustrates the process of producing good quality sections and demonstrates the technical difficulties and methods with which to overcome them.

脱钙骨组织学，形态计量学和荧光染料分析制备

Undecalcified bone histology demonstrates the micro-architecture of bone. It shows both the mineralised and cellular components of bone, which provides ...

Flow Cytometric Analysis of Extracellular Vesicles from Cell-conditioned Media

Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for phenotypic analyses of extracellular vesicles (EV) including exosomes (Exo) in the peripheral blood and other body fluids. The small size of EV mandates the use of dedicated instruments having a detection threshold around 50-100 nm. Alternatively, EV can be bound to latex microbeads that can be detected by FC. Microbeads, conjugated with antibodies that recognize EV-associated markers/Cluster of Differentiation CD63, CD9, and CD81 can be used for EV capture. Exo isolated from CM can be analyzed with or without pre-enrichment by ultracentrifugation. This approach is suitable for EV analyses using conventional FC instruments. Our results demonstrate a linear correlation between Mean Fluorescence Intensity (MFI) values and EV concentration. Disrupting EV through sonication dramatically decreased MFI, indicating that the method does not detect membrane debris. We report an accurate and reliable method for the analysis of EV surface antigens, which can be easily implemented in any laboratory.

The protocol describes a reproducible method designed for use with cell culture supernatants to detect surface epitopes on small extracellular vesicles (EV). It utilizes specific EV immunoprecipitation using beads coupled with antibodies that recognize surface antigen CD9, CD63, and CD81. The method is optimized for downstream flow cytometry analysis.

细胞调理介质细胞外囊泡的流式细胞学分析

Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for ...

Tissue Collection and RNA Extraction from the Human Osteoarthritic Knee Joint

Osteoarthritis (OA) is a chronic and degenerative joint disease most often affecting the knee. As there is currently no cure, total knee arthroplasty (TKA) is a common surgical intervention. Experiments using primary human OA tissues obtained from TKA provide the capability to investigate disease mechanisms ex vivo. While OA was previously thought to impact mainly the cartilage, it is now known to impact multiple tissues in the joint. This protocol describes patient selection, sample processing, tissue homogenization, RNA extraction, and quality control (based on RNA purity, integrity, and yield) from each of seven unique tissues to support disease mechanism investigation in the knee joint. With informed consent, samples were obtained from patients undergoing TKA for OA. Tissues were dissected, washed, and stored within 4 h of surgery by flash freezing for RNA or formalin fixation for histology. Collected tissues included articular cartilage, subchondral bone, meniscus, infrapatellar fat pad, anterior cruciate ligament, synovium, and vastus medialis oblique muscle. RNA extraction protocols were tested for each tissue type. The most significant modification involved the method of disintegration used for low-cell, high-matrix, hard tissues (considered as cartilage, bone, and meniscus) versus relatively high-cell, low-matrix, soft tissues (considered as fat pad, ligament, synovium, and muscle). It was found that pulverization was appropriate for hard tissues, and homogenization was appropriate for soft tissues. A proclivity for some subjects to yield higher RNA integrity number (RIN) values than other subjects consistently across multiple tissues was observed, suggesting that underlying factors such as disease severity may impact RNA quality. The ability to isolate high-quality RNA from primary human OA tissues provides a physiologically relevant model for sophisticated gene expression experiments, including sequencing, that can lead to clinical insights that are more readily translated to patients.

Primary tissues obtained from patients following total knee arthroplasty provide an experimental model for osteoarthritis research with maximal clinical translatability. This protocol describes how to identify, process, and isolate RNA from seven unique knee tissues to support mechanistic investigation in human osteoarthritis.

从人骨关节炎膝关节收集和RNA提取

Osteoarthritis (OA) is a chronic and degenerative joint disease most often affecting the knee. As there is currently no cure, total knee arthroplasty ...

Using Real-Time Cell Metabolic Flux Analyzer to Monitor Osteoblast Bioenergetics

Bone formation by osteoblasts is an essential process for proper bone acquisition and bone turnover to maintain skeletal homeostasis, and ultimately, prevent fracture. In the interest to both optimize peak bone mass and combat various musculoskeletal diseases (i.e., post-menopausal osteoporosis, anorexia nervosa, type 1 and 2 diabetes mellitus), incredible efforts have been made in the field of bone biology to fully characterize osteoblasts throughout their differentiation process. Given the primary role of mature osteoblasts to secrete matrix proteins and mineralization vesicles, it has been noted that these processes take an incredible amount of cellular energy, or adenosine triphosphate (ATP). The overall cellular energy status is often referred to as cellular bioenergetics, and it includes a series of metabolic reactions that sense substrate availability to derive ATP to meet cellular needs. Therefore, the current method details the process of isolating primary, murine bone marrow stromal cells (BMSCs) and monitoring their bioenergetic status using the Real-time cell metabolic flux analyzer at various stages in osteoblast differentiation. Importantly, these data have demonstrated that the metabolic profile changes dramatically throughout osteoblast differentiation. Thus, using this physiologically relevant cell type is required to fully appreciate how a cell's bioenergetic status can regulate the overall function.

Real-time cell metabolic flux assay measures the oxygen consumption rate and extracellular acidification rate, which corresponds to mitochondrial and glycolytic adenosine triphosphate production, using pH and oxygen sensors. The manuscript explains a method to understand the energy status of osteoblasts and the characterization and interpretation of the cellular bioenergetic status.

使用实时细胞代谢通量分析仪监测成骨细胞生物能量学

Bone formation by osteoblasts is an essential process for proper bone acquisition and bone turnover to maintain skeletal homeostasis, and ultimately, ...

An Improved Chemotaxis Assay for the Rapid Identification of Rhizobacterial Chemoattractants in Root Exudates

Chemotaxis identification is very important for the research and application of rhizosphere growth-promoting bacteria. We established a straightforward method to quickly identify the chemoattractants that could induce the chemotactic movement of rhizosphere growth-promoting bacteria on sterile glass slides via simple steps. Bacteria solution (OD600 = 0.5) and sterile chemoattractant aqueous solution were added dropwise on the glass slide at an interval of 1 cm. An inoculating loop was used to connect the chemoattractant aqueous solution to the bacterial solution. The slide was kept at room temperature for 20 min on the clean bench. Finally, the chemoattractant aqueous solution was collected for bacterial counting and microscopic observation. In this study, through multiple comparisons of experimental results, the method overcame multiple shortcomings of traditional bacterial chemotaxis methods. The method reduced the error of plate counting and shortened the experimental cycle. For the identification of chemoattractant substances, this new method can save 2-3 days compared to the traditional method. Additionally, this method allows any researcher to systematically complete a bacterial chemotaxis experiment within 1-2 days. The protocol can be considered a valuable resource for understanding plant-microbe interactions.

Here, we present an improved chemotaxis assay protocol. The goal of this protocol is to reduce the steps and costs of traditional bacterial chemotaxis methods and to serve as a valuable resource for understanding plant-microbe interactions.

一种用于快速鉴定根系分泌物中根细菌化学引诱剂的改进趋化性测定

Chemotaxis identification is very important for the research and application of rhizosphere growth-promoting bacteria. We established a straightforward ...

Topical Application Bioassay to Quantify Insecticide Toxicity for Mosquitoes and Fruit Flies

The continued use of insecticides for public health and agriculture has led to widespread insecticide resistance and hampering of control methods. Insecticide resistance surveillance of mosquito populations is typically done through Centers for Disease Control and Prevention (CDC) bottle bioassays or World Health Organization (WHO) tube tests. However, these methods can result in a high degree of variability in mortality data due to variable insecticide contact with&#160;the insect, the relatively small numbers of organisms tested, extensive variation in mass between populations, and constantly changing environmental conditions, leading to variable outcomes. This paper presents the topical application bioassay, adapted as a high-throughput phenotypic bioassay for both mosquitoes and fruit flies, to test large numbers of insects along&#160;a range of insecticide concentrations.
This assay 1) ensures consistent treatment and insecticide contact with every organism, 2) produces highly specific dose-response curves that account for differences in average mass between strains and sexes (which is particularly important for field-collected organisms), and 3) allows for the calculation of statistically rigorous median lethal doses (LD50), which are necessary for resistance ratio comparisons-an alternative surveillance approach from diagnostic dose mortality, which is also used for larvicide resistance surveillance. This assay will be a complementary tool for accurately phenotyping mosquito populations and, as illustrated using fruit flies, is easily adaptable for use with other insects. We argue that this assay will help fill the gap between genotypic and phenotypic insecticide resistance in multiple insect species.

We describe the methodology and importance of the topical application bioassay to measure insecticide susceptibility in mosquitoes and fruit flies. The presented assay is high-throughput, utilizes insect mass-thus allowing for calculating a mass-relativized lethal dose instead of concentration-and likely has lower variability than other similar methods.

局部应用生物测定以量化蚊子和果蝇的杀虫剂毒性

The continued use of insecticides for public health and agriculture has led to widespread insecticide resistance and hampering of control methods. ...

The Caco-2 Cell Bioassay for Measurement of Food Iron Bioavailability

Knowledge of Fe bioavailability is critical to the assessment of the nutritional quality of Fe in foods. In vivo measurement of Fe bioavailability is limited by cost, throughput, and the caveats inherent to isotopic labeling of the food Fe. Thus, there exists a critical need for an approach that is high-throughput and cost-effective. The Caco-2 cell bioassay was developed to satisfy this need. The Caco-2 cell bioassay for Fe bioavailability utilizes simulated gastric and intestinal digestion coupled with culture of a human intestinal epithelial cell line known as Caco-2. In Caco-2 cells, Fe uptake stimulates the intracellular formation of ferritin, an Fe storage protein easily measured by enzyme-linked immunosorbent assay (ELISA). Ferritin forms in proportion to Fe uptake; thus, by measuring Caco-2 cell ferritin production, one can assess intestinal Fe uptake from simulated food digests into the enterocyte. 
Via this approach, the model replicates the key initial step that determines food Fe bioavailability. Since its inception in 1998, this model approach has been rigorously compared to factors known to influence human Fe bioavailability. Moreover, it has been applied in parallel studies, with three human efficacy studies evaluating Fe biofortified crops. In all cases, the bioassay correctly predicted the relative amounts of Fe bioavailability from the factors, crops, and overall diet. This paper provides detailed methods on Caco-2 cell culture coupled with the in vitro digestion process and cell ferritin ELISA necessary to conduct the Caco-2 cell bioassay for Fe bioavailability.

The Caco-2 cell bioassay for iron (Fe) bioavailability represents a cost-effective and versatile approach to assess Fe bioavailability from foods, food products, supplements, meals, and even diet regimens. Thoroughly validated to human studies, it represents the state of the art for studies of Fe bioavailability.

用于测量食品铁生物利用度的Caco-2细胞生物测定法

Knowledge of Fe bioavailability is critical to the assessment of the nutritional quality of Fe in foods. In vivo measurement of Fe bioavailability is ...

人工软骨植入物通过软骨内骨化进行骨再生

Integrated Bone Formation Through In Vivo Endochondral Ossification Using Mesenchymal Stem Cells

Conventional bone regeneration therapy using mesenchymal stem cells (MSCs) is difficult to apply to bone defects larger than the critical size because it does not have a mechanism to induce angiogenesis. Implanting artificial cartilage tissue fabricated from MSCs induces angiogenesis and bone formation in vivo via endochondral ossification (ECO). Therefore, this ECO-mediated approach may be a promising bone regeneration therapy in the future. An important aspect of the clinical application of this ECO-mediated approach is establishing a protocol for preparing enough cartilage to be implanted to repair the bone defect. It is especially not practical to design a single mass of grafted cartilage of a size that conforms to the shape of the actual bone defect. Therefore, the cartilage to be transplanted must have the property of forming bone integrally when multiple pieces are implanted. Hydrogels may be an attractive tool for scaling up tissue-engineered grafts for endochondral ossification to meet clinical requirements. Although many naturally derived hydrogels support MSC cartilage formation in vitro and ECO in vivo, the optimal scaffold material to meet the needs of clinical applications has yet to be determined. Hyaluronic acid (HA) is a crucial component of the cartilage extracellular matrix and is a biodegradable and biocompatible polysaccharide. Here, we show that HA hydrogels have excellent properties to support in vitro differentiation of MSC-based cartilage tissue and promote endochondral bone formation in vivo.

作者聚焦：通过血管化人工软骨整合增强骨再生 

Bone therapy via endochondral ossification by implanting artificial cartilage tissue produced from mesenchymal stem cells has the potential to circumvent the drawbacks of conventional therapies. Hyaluronic acid hydrogels are effective in scaling up uniformly differentiated cartilage grafts as well as creating integrated bone with vascularization between fused grafts in vivo.

使用间充质干细胞通过 体内 软骨内骨化进行整合骨形成

Conventional bone regeneration therapy using mesenchymal stem cells (MSCs) is difficult to apply to bone defects larger than the critical size because it ...