Name: a 5-mc dot blot assay quantifying the dna methylation level of chondrocyte dedifferentiation in vitro
Uploaded: 2017-05-17T13:00:00
Description: Watch this Scientific Journal Video about A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro at JoVE.com

This work was supported by the following grants: Natural Science Foundation of China (No. 81572198; No. 81260161; No. 81000460); Natural Science Foundation of Guangdong Province, China (No. 2015A030313772); China Postdoctoral Science Foundation Funded Project (No. 2013M530385); The Medical Research Foundation of Guangdong Province, China (No. A2016314); Shenzhen Science and Technology Projects (No. JCYJ20160301111338144; No. JSGG20151030140325149; No. JSGG20140519105550503; No.GJHZ20130412153906739; No. JCYJ20140414170821160; No.JCYJ20140414170821200).

This study was approved by the Human Ethics Committee of Shenzhen Second People&#39;s Hospital.
1. Human Articular Cartilage Tissue Collection and Chondrocyte Culture
<ol>
	<li>Preparation of materials
	<ol>
		<li>Prepare Dulbecco&#39;s modified eagle medium (DMEM) medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. Prepare 1 mg/mL collagenase II, 0.25% trypsin-EDTA, phosphate-buffered saline (PBS), and a cell strainer (40 &#181;m nylon).</li>
	</...

<ol>
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W., 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=Exploring+Genome-wide+DNA+Methylation+Profiles+Altered+in+Kashin-Beck+Disease+Using+Infinium+Human+Methylation+450+Bead+Chips.">Exploring Genome-wide DNA Methylation Profiles Altered in Kashin-Beck Disease Using Infinium Human Methylation 450 Bead Chips.</a> Biomed Environ Sci. 29 (7), 539-543 (2016).</li><li>Li, X. L., 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=Optimization+of+an+HPLC+Method+for+Determining+the+Genomic+Methylation+Levels+of+Taxus+Cells.">Optimization of an HPLC Method for Determining the Genomic Methylation Levels of Taxus Cells.</a> J Chromatogr Sci. 54 (2), 200-205 (2016).</li><li>Maghbooli, Z., 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=Global+DNA+methylation+as+a+possible+biomarker+fordiabetic+retinopathy.">Global DNA methylation as a possible biomarker fordiabetic retinopathy.</a> Diabetes Metab Res Rev. 31 (2), 183-189 (2015).</li><li>Barlic, A., Drobnic, M., Malicev, E., Kregar-Velikonja, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+analysis+of+gene+expression+in+human+articular+chondrocytes+assigned+for+autologous+implantation.">Quantitative analysis of gene expression in human articular chondrocytes assigned for autologous implantation.</a> J Orthop Res. 26 (6), 847-853 (2008).</li><li>Legendre, F., 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=Enhanced+hyaline+cartilage+matrix+synthesis+in+collagen+sponge+scaffolds+by+using+siRNA+to+stabilizechondrocytes+phenotype+cultured+with+bone+morphogenetic+protein-2+under+hypoxia.">Enhanced hyaline cartilage matrix synthesis in collagen sponge scaffolds by using siRNA to stabilizechondrocytes phenotype cultured with bone morphogenetic protein-2 under hypoxia.</a> Tissue Eng Part C Methods. 19 (7), 550-567 (2013).</li><li>Niethammer, T. R., 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=Analysis+of+the+autologous+chondrocyte+quality+of+matrix-based+autologous+chondrocyte+implantation+in+the+knee+joint.">Analysis of the autologous chondrocyte quality of matrix-based autologous chondrocyte implantation in the knee joint.</a> Int Orthop. 40 (1), 205-212 (2016).</li><li>Hayatsu, 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+bisulfite+genomic+sequencing+used+in+the+analysis+of+epigenetic+states,+a+technique+in+the+emerging+environmental+genotoxicology+research.">The bisulfite genomic sequencing used in the analysis of epigenetic states, a technique in the emerging environmental genotoxicology research.</a> Mutat Res. 659 (1-2), 77-82 (2008).</li><li>Haque, N., Nishiguchi, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bisulfite+sequencing+for+cytosine-methylation+analysis+in+plants.">Bisulfite sequencing for cytosine-methylation analysis in plants.</a> Methods Mol Biol. 744, 187-197 (2011).</li><li>Ananiev, G. 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Chondrocyte dedifferentiation in vitro severely compromises the outcome of ACI in the treatment of cartilage defect repair11,12. To optimize ACI outcome, it is crucial to avoid the use of dedifferentiated chondrocytes13. Studies have suggested that general DNA methylation level is associated with the extent of the chondrocyte dedifferentiation4,6. Thus, it is imperative to...

Autologous chondrocyte implantation (ACI) is a relatively new, state-of-the-art procedure to treat articular cartilage defects1,2. One of the crucial steps in ACI is amplification of chondrocytes via monolayer culture in vitro. During amplification, the hyaline chondrocytes easily lose their phenotype and become dedifferentiated, which is undesirable for ACI treatment3,4. To optimize the outcome of ACI treatment, the extent of chondrocyte dedifferentiation should be determined before replantation. It is imperative to establish an economic and rapid way to determine the chondrocytes&#39; status. Recently, the association between DNA methylation and chondrocyte dedifferentiation has attracted much attention4,5,6. DNA methylation is a process by which methyl groups are added to DNA, resulting in the conversion of cytosine residues to 5-methylcytosine (5-mC).
To elucidate the biology of DNA methylation in chondrocyte dedifferentiation, the first step is to evaluate the DNA methylation level of chondrocytes, which so far has proven challenging. Bisulfite genomic sequencing is the most widely used technique to analyze DNA methylation7,8. In this assay, bisulfite conversion causes DNA degradation, and thus a substantial amount of sample must be provided for the assay. Also, high-performance liquid chromatography (HPLC) has been used to quantify global DNA methylation levels9,10. However, HPLC analysis requires genomic DNA digestion. Furthermore, advanced and expensive experimental instruments are required. Therefore, in addition to the high cost, these experimental procedures are time consuming. Anti-5-mC antibodies have now become commercially available, which has created the possibility for immune blotting of 5-mC-containing genomic DNA from complex genomes.
In this report, we extracted genomic DNA from chondrocytes grown in a series of monolayer cultures. We used a dot blot assay to evaluate the 5-mC content in human chondrocytes with different numbers of passages. We found that 5-mC content was increased in highly dedifferentiated chondrocytes compared to chondrocytes with low-grade dedifferentiation. Additionally, we identified a relationship between dedifferentiation status and 5-mC levels. Finally, we reported that the changes in 5-mC content were associated with the chondrocyte phenotype. Therefore, the 5-mC dot blot assay is a reliable, simple, and rapid method to detect the DNA methylation level in chondrocytes.

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			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM&#160;&#160;</td>
			<td>Gibco Inc.</td>
			<td>11965&#8211;092</td>
			<td>Warm in 37 &#176;C water bath before use</td>
		</tr>
		<tr>
			<td rowspan="2">Phosphate-Buffered Saline(PBS)</td>
			<td rowspan="2">HyClone Inc.</td>
			<td rowspan="2">SH30256.01B</td>
			<td>D-PBS, free of&#160;</td>
		</tr>
		<tr>
			<td>Ca2+/Mg2+</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Gibco Inc.</td>
			<td>10099-141</td>
			<td></td>
		</tr>
		<tr>
			<td>0.25%Trypsin/EDTA</td>
			<td>Gibco Inc.</td>
			<td>25200-056</td>
			<td></td>
		</tr>
		<tr>
			<td>1%Penicillin-Streptomycin</td>
			<td>Gibco Inc.</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Mallinckrodt</td>
			<td>4440</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoamyl Alcohol</td>
			<td>Sigma</td>
			<td>I-3643</td>
			<td></td>
		</tr>
		<tr>
			<td>Phenol</td>
			<td>Gibco BRL</td>
			<td>15513-039</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Gibco BRL</td>
			<td>24568-2</td>
			<td></td>
		</tr>
		<tr>
			<td>TAE buffer&#160;</td>
			<td>Bio Whittaker</td>
			<td>16-011V</td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled Water</td>
			<td>Gibco BRL</td>
			<td>15230-170</td>
			<td></td>
		</tr>
		<tr>
			<td>1 M Tris-HCl</td>
			<td>Biosharp Inc.</td>
			<td>BL514A</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween20</td>
			<td>Biotopped Inc.</td>
			<td>C58H114O26</td>
			<td></td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>Proliant Inc.</td>
			<td>68700</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase, Type II</td>
			<td>Sigma-Aldrich</td>
			<td>C6885</td>
			<td></td>
		</tr>
		<tr>
			<td>Names&#160;&#160;&#160;&#160;&#160;</td>
			<td>Company&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td>Catalog number&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainer(40&#956;m nylon&#65289;</td>
			<td>FALCON Inc.</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemocytometer</td>
			<td>ISOLAB Inc.</td>
			<td>075.03.001</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon 100 mm&#160; dish</td>
			<td>Corning</td>
			<td>353003</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge Tubes</td>
			<td>TPP AG</td>
			<td>91050</td>
			<td>Gamma-sterilized</td>
		</tr>
		<tr>
			<td>High-speed centrifuge</td>
			<td>Eppendorf</td>
			<td>5804R</td>
			<td></td>
		</tr>
		<tr>
			<td>ThermoMixer</td>
			<td>MIULAB</td>
			<td>MTH-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon dioxide cell incubator</td>
			<td>Thermo scientific</td>
			<td>3111</td>
			<td></td>
		</tr>
		<tr>
			<td>Chemi-imaging Analyse System</td>
			<td>UVITEC Cambridge</td>
			<td>ALLIANCE</td>
			<td></td>
		</tr>
	</tbody>
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a 5-mc dot blot assay quantifying the dna methylation level of chondrocyte dedifferentiation in vitro

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global DNA methylation level of chondrocytes is considered to be a suitable biomarker for the loss of the chondrocyte phenotype. However, results based on different experimental methods can be inconsistent. Therefore, it is important to establish a precise, simple, and rapid method to quantify global DNA methylation levels during chondrocyte dedifferentiation.
Current genome-wide methylation analysis techniques largely rely on bisulfite genomic sequencing. Due to DNA degradation during bisulfite conversion, these methods typically require a large sample volume. Other methods used to quantify global DNA methylation levels include high-performance liquid chromatography (HPLC). However, HPLC requires complete digestion of genomic DNA. Additionally, the prohibitively high cost of HPLC instruments limits HPLC&#39;s wider application.
In this study, genomic DNA (gDNA) was extracted from human chondrocytes cultured with varying number of passages. The gDNA methylation level was detected using a methylation-specific dot blot assay. In this dot blot approach, a gDNA mixture containing the methylated DNA to be detected was spotted directly onto an N+ membrane as a dot inside a previously drawn circular template pattern. Compared with other gel electrophoresis-based blotting approaches and other complex blotting procedures, the dot blot method saves significant time. In addition, dot blots can detect overall DNA methylation level using a commercially available 5-mC antibody. We found that the DNA methylation level differed between the monolayer subcultures, and therefore could play a key role in chondrocyte dedifferentiation. The 5-mC dot blot is a reliable, simple, and rapid method to detect the general DNA methylation level to evaluate chondrocyte phenotype.

Chondrocytes were cultured in a monolayer up to passage 6 (P6). Chondrocytes showed progressive phenotypic changes with successive passages of the monolayer culture. The P0 chondrocyte morphology was round, whereas the cells became highly pinched and flattened with successive passages up to P6 (Figure 1). This morphology change is typical of the chondrocyte dedifferentiation process. Meanwhile, results of the heat map indicated that the general methylation level of CpG si...

Watch this Scientific Journal Video about A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro at JoVE.com

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

We present a method to quantify DNA methylation based on the 5-methylcytosine (5-mC) dot blot. We determined the 5-mC levels during chondrocyte dedifferentiation. This simple technique could be used to quickly determine the chondrocyte phenotype in ACI treatment.

A 5-mC Dot Blot Assay Quantifying the DNA Methylation Level of Chondrocyte Dedifferentiation In Vitro

The dedifferentiation of hyaline chondrocytes into fibroblastic chondrocytes often accompanies monolayer expansion of chondrocytes in vitro. The global ...

The overall goal of this experiment is to determine the 5-Methylcytosine levels during chondrocyte dedifferentiation. This method shows can help answer key questions in cell-based cartilage defect treatment such as autologous chondrocyte implantation. The main advantage of this technique is that it is a reliable, simple and rapid method for detecting the general DNA methylation level to evalute chondrocyte phenotype.The implication of this technology is standard to our share of autologous chondrocyte implantation because DNA methylation during chondrocyte dedifferentiation is a major obstacle for autologous chondrocyte implantation treatment for cartilage defects. Though this method can provide insight into DNA methylation levels in chondrocyte dedifferentiation, it can also be applied to other studies of diseases, such osteoarthritis. We first had the idea for this method when we read the protocols in the references of a dot blot method.Please show demonstration of this method is critical as a dot blot states are difficult to name. Genomic DNA should be denatured and then be serially diluted. Then be supported on a positively-charged nylon membrane.Demonstrating the procedures will be Zhaofeng Jia, a graduate student from our lab. The articular cartilage tissues used in this study were isolated from the knee joints of donor patients after trauma. Using a sterile scalpel, dice the cartilage into one to two cubic millimeter pieces.Then add one milligram per milliliter of collagenase II and DMEM to the minced cartilage. And incubate at 37 degrees Celsius for 12 to 16 hours to digest the chondrocytes. On the following day, filter the resulting cell suspension through a 40 micrometer cell strainer.Spin down the cells. Discard the supernatant, add PBS, and spin down again. Count the cells with a hemocytometer.And seed at a density of 20, 000 to 30, 000 cells per centimeter squared and DMEM supplemented with 10%FBS and 1%penicillin streptomycin. Culture in an incubator at 37 degrees Celsius for 48 hours. Harvest subconfluent cells using 0.25%trypsin EDTA.And replate at a density of 6, 600 cells per centimeter squared. Culture the chondrocytes in monolayers for up to six passages and assess at passages one, two, three, four, and five. To begin this procedure, collect cells by trypsinization and centrifugation.Then resuspend cells in 500 microliters of lysis buffer per 10 million cells by pipetting and rapid inversion. Incubate for one hour at 37 degrees Celsius. Add proteinase K at a concentration of 160 micrograms per milliliter of cell lysate and invert the mixture vigorously.Incubate for six hours at 55 degrees Celsius. Add to each sample one volume of Tris pH 7.9 saturated phenol to chloroform to isoamyl alcohol. Shake the sample by hand thoroughly for approximately 20 seconds.Centrifuge the samples at room temperature at 13, 000 times G for five minutes. Remove the upper aqueous phase, and transfer to a fresh tube. To remove the phenol, add an equal volume of chloroform to each tube.Shake by hand, and spin down. Transfer the top aqueous phase to a fresh tube. Add 0.1 sample volume of three molar sodium acetate pH eight and two volumes of 100%ethanol.Store the tubes at negative 20 degrees Celsius overnight to precipitate the genomic DNA. On the following day, centrifuge the samples at four degrees Celsius for 10 minutes at 16, 000 times G to pellet the genomic DNA. Wash the samples with 70%ethanol.And centrifuge at four degrees Celsius for two minutes at 13, 000 times G.Remove the supernatant carefully and air dry the DNA pellet. Resuspend the DNA in 10 millimolar tris pH eight 0.1 millimolar EDTA. Start this procedure by denaturing the isolated DNA in 0.1 molar sodium hydroxide for 10 minutes at 95 degrees Celsius.Neutralize the DNA with one molar ammonium acetate on ice. And then dilute twofold with double distilled water. The most critical step in the dot blot assays is the spotting of the samples, and remember do it slowly and carefully.Try to minimize each spotted array to three to four millimeter in diameter. Using a narrow mouth pipette tip, carefully spot two microliters of the serial diluted genomic DNA onto a positively charged nylon membrane at the center of the grid. Blot the membrane at 80 degrees Celsius for 30 minutes.Next, block the non-specific antibody binding sites by soaking the membrane in 5%BSA in TBST in a 10 centimeter petri dish for one hour at room temperature with gentle shaking. After one hour, wash the membrane three times in TBST for five minutes each time. Incubate the membrane with a mouse anti-5-methylcytosine monoclonal antibody in TBST at four degrees Celsius overnight.On the following day, wash the membrane three times in TBST for five minutes each time. Then incubate with a secondary antibody, horseradish peroxidase conjugated sheep anti-mouse immunoglobulin G in TBST for one hour at room temperature. After washing the membrane in TBST as before, add the enzyme substrate to the membrane and incubate for five to 10 minutes.Finally, visualize the secondary antibody signal using a chemiluminescence kit according to the manufacturer's instructions. Chondrocytes cultured in a monolayer up to passage six showed progressive phenotypic changes becoming highly pinched and flattened with successive passages. This morphology change is typical of the chondrocyte dedifferentiation process.Genomic DNA was isolated from chondrocytes after varying number of passages and DNA methylation levels were assessed by a 5-Methylcytosine specific dot blot assay. Intensities of the dots were then analyzed by image J.Progressively elevated five methylcytosine levels were observed with prolonged subculture, suggesting an association between generally increased methylation levels and chondrocyte dedifferentiation. Once mastered, this technique can be done in 24 hours if it is performed properly.While attempting this procedure, it's important to remember to maximize genomic DNA concentration and purity. Following this procedure other methods like genomic DNA machination profiling can be performed to answer additional questions such as chondrocytes of dedifferentiation in monoculture. After its development, this technique paved the way for researchers in the field of autologous chondrocyte implantation to evaluate DNA machination of chondrocytes and determine the chondrocyte phenotype in cartilage defect treatment.After watching this video, you should have a good understanding of how to use 5-Methylcytosine dot blot to detect degenerate machination lever to evaluate the chondrocyte phenotype. Don't forget that working with phenol can be extremely hazardous and gloves should always be worn while performing this procedure.

a-5-mc-dot-blot-assay-quantifying-dna-methylation-level-chondrocyte

Research

JoVE Journal

Developmental Biology

Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays

Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS). We use an in vitro myelination assay, an established model for studying CNS myelination in vitro. To do this, oligodendrocyte precursor cells (OPCs) are added to the purified primary rodent dorsal root ganglion (DRG) neurons to form myelinating co-cultures. In order to specifically interrogate the roles that particular proteins expressed by oligodendrocytes exert upon myelination we have developed protocols that selectively transduce OPCs using the lentivirus overexpressing wild type, constitutively active or dominant negative proteins before being seeded onto the DRG neurons. This allows us to specifically interrogate the roles of these oligodendroglial proteins in regulating myelination. The protocols can also be applied in the study of other cell types, thus providing an approach that allows selective manipulation of proteins expressed by a desired cell type, such as oligodendrocytes for the targeted study of signaling and compensation mechanisms. In conclusion, combining the in vitro myelination assay with lentiviral infected OPCs provides a strategic tool for the analysis of molecular mechanisms involved in myelination.

Production and Use of Lentivirus to Selectively Transduce Primary Oligodendrocyte Precursor Cells for In Vitro Myelination Assays

Here we present protocols that offer a flexible and strategic foundation for virally manipulating oligodendrocyte precursor cells to overexpress proteins of interest in order to specifically interrogate their role in oligodendrocytes via the in vitro model of central nervous system myelination.

Myelination is a complex process that involves both neurons and the myelin forming glial cells, oligodendrocytes in the central nervous system (CNS) and ...

Generation of Human Adipose Stem Cells through Dedifferentiation of Mature Adipocytes in Ceiling Cultures

Mature adipocytes have been shown to reverse their phenotype into fibroblast-like cells in vitro through a technique called ceiling culture. Mature adipocytes can also be isolated from fresh adipose tissue for depot-specific characterization of their function and metabolic properties. Here, we describe a well-established protocol to isolate mature adipocytes from adipose tissues using collagenase digestion, and subsequent steps to perform ceiling cultures. Briefly, adipose tissues are incubated in a Krebs-Ringer-Henseleit buffer containing collagenase to disrupt tissue matrix. Floating mature adipocytes are collected on the top surface of the buffer. Mature cells are plated in a T25-flask completely filled with media and incubated upside down for a week. An alternative 6-well plate culture approach allows the characterization of adipocytes undergoing dedifferentiation. Adipocyte morphology drastically changes over time of culture. Immunofluorescence can be easily performed on slides cultivated in 6-well plates as demonstrated by FABP4 immunofluorescence staining. FABP4 protein is present in mature adipocytes but down-regulated through dedifferentiation of fat cells. Mature adipocyte dedifferentiation may represent a new avenue for cell therapy and tissue engineering.

Mature adipocytes may represent an abundant source of stem cells through dedifferentiation, which leads to a homogenous population of fibroblast-like cells. Collagenase digestion is used to isolate mature adipocytes from human fat. The goal of our protocol is to obtain multipotent, dedifferentiated fat cells from human mature adipocytes.

Mature adipocytes have been shown to reverse their phenotype into fibroblast-like cells in vitro through a technique called ceiling culture. Mature ...

Visualization of Chondrocyte Intercalation and Directional Proliferation via Zebrabow Clonal Cell Analysis in the Embryonic Meckel&#8217;s Cartilage

Development of the vertebrate craniofacial structures requires precise coordination of cell migration, proliferation, adhesion and differentiation. Patterning of the Meckel&#39;s cartilage, a first pharyngeal arch derivative, involves the migration of cranial neural crest (CNC) cells and the progressive partitioning, proliferation and organization of differentiated chondrocytes. Several studies have described CNC migration during lower jaw&#160;morphogenesis, but the details of how the chondrocytes achieve organization in the growth and extension of Meckel&#8217;s cartilage remains unclear. The sox10 restricted and chemically induced Cre recombinase-mediated recombination generates permutations of distinct fluorescent proteins (RFP, YFP and CFP), thereby creating a multi-spectral labeling of progenitor cells and their progeny, reflecting distinct clonal populations. Using confocal time-lapse photography, it is possible to observe the chondrocytes behavior during the development of the zebrafish Meckel&#8217;s cartilage.
Multispectral cell labeling enables scientists to demonstrate extension of the Meckel&#8217;s chondrocytes.&#160;During extension phase of the Meckel&#8217;s cartilage, which prefigures the mandible, chondrocytes intercalate to effect extension as they stack in an organized single-cell layered row. Failure of this organized intercalating process to mediate cell extension provides the cellular mechanistic explanation for hypoplastic mandible that we observe in mandibular malformations.

Cell organization of craniofacial bones has long been hypothesized but never directly visualized. Multi-spectral cell labeling and in vivo live imaging allows visualization of dynamic cell behavior in zebrafish lower jaw. Here, we detail the protocol to manipulate Zebrabow transgenic fish and directly observe cell intercalation and morphological changes of chondrocytes in the Meckel&#8217;s cartilage.

Development of the vertebrate craniofacial structures requires precise coordination of cell migration, proliferation, adhesion and differentiation. ...

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition

Fibrosis is often involved in the pathogenesis of various chronic progressive diseases such as interstitial pulmonary disease. Pathological hallmark is the formation of fibroblastic foci, which is associated with the disease severity. Mesenchymal cells consisting of the fibroblastic foci are proposed to be derived from several cell sources, including originally resident intrapulmonary fibroblasts and circulating fibrocytes from bone marrow. Recently, mesenchymal cells that underwent epithelial-mesenchymal transition (EMT) have been also supposed to contribute to the pathogenesis of fibrosis. In addition, EMT can be induced by transforming growth factor &#946;, and EMT can be enhanced by pro-inflammatory cytokines like tumor necrosis factor &#945;. The gel contraction assay is an ideal in vitro model for the evaluation of contractility, which is one of the characteristic functions of fibroblasts and contributes to wound repair and fibrosis. Here, the development of a gel contraction assay is demonstrated for evaluating contractile ability of mesenchymal cells that underwent EMT.

Development of an In Vitro Assay to Evaluate Contractile Function of Mesenchymal Cells that Underwent Epithelial-Mesenchymal Transition

Here, we describe the development and application of a gel contraction assay for evaluating contractile function in mesenchymal cells that underwent epithelial-mesenchymal transition.

Fibrosis is often involved in the pathogenesis of various chronic progressive diseases such as interstitial pulmonary disease. Pathological hallmark is ...

In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity

14 day-old mouse ovarian tissue and preantral follicles isolated from same-aged mice were incubated in a simulated microgravity culture system. We quantitatively assessed follicle survival, measured follicle and oocyte diameters, and examined ultrastructure of the oocytes produced from the system. We observed decreased follicle survival, downregulation of expressions of proliferating cell nuclear antigen and growth differentiation factor 9, as indicators for the development of granulosa cells and oocytes, respectively, and oocyte ultrastructural abnormalities under the simulated microgravity condition. The simulated microgravity experimental setup needs to be optimized to provide a model for investigation of the mechanisms involved in the oocyte/follicle in vitro development.

In Vitro Growth of Mouse Preantral Follicles Under Simulated Microgravity

A highly promising technique to generate tissue constructs without using matrix is to culture cells in a simulated microgravity condition. Using a rotary culture system, we examined ovarian follicle growth and oocyte maturation in terms of follicle survival, morphology, growth, and oocyte function under the simulated microgravity condition.

14 day-old mouse ovarian tissue and preantral follicles isolated from same-aged mice were incubated in a simulated microgravity culture system. We ...

Quantifying Branching Density in Rat Mammary Gland Whole-mounts Using the Sholl Analysis Method

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The effects these exposures have on mammary gland development are typically evaluated using either basic dimensional measurements or by scoring morphological characteristics. However, the broad range of methods for interpreting developmental changes could lead to inconsistent translations across laboratories. A common method of assessment is needed so that proper interpretations can be formed from data being compared across studies. The present study describes the application of the Sholl analysis method to quantify mammary gland branching characteristics. The Sholl method was originally developed for use in quantifying neuronal dendritic patterns. By using ImageJ, an open-source image analysis software package, and a plugin developed for this analysis, the mammary gland branching density and the complexity of a mammary gland from a peripubertal female rat were determined. The methods described here will enable the use of the Sholl analysis as an effective tool for quantifying an important characteristic of mammary gland development.

Mammary gland development in the rodent has typically been evaluated using descriptive assessments or by measuring basic physical attributes. Branching density is an indicator of mammary development that is difficult to quantify objectively. This protocol describes a reliable method for the quantitative assessment of mammary gland branching characteristics.

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The ...

The Aortic Ring Co-culture Assay: A Convenient Tool to Assess the Angiogenic Potential of Mesenchymal Stromal Cells In Vitro

Angiogenesis is a complex, highly regulated process responsible for providing and maintaining adequate tissue perfusion. Insufficient vasculature maintenance and pathological malformations can result in severe ischemic diseases, while overly abundant vascular development is associated with cancer and inflammatory disorders. A promising form of pro-angiogenic therapy is the use of angiogenic cell sources, which can provide regulatory factors as well as physical support for newly developing vasculature.
Mesenchymal Stromal Cells (MSCs) are extensively investigated candidates for vascular regeneration due to their paracrine effects and their ability to detect and home to ischemic or inflamed tissues. In particular, first trimester human umbilical cord perivascular cells (FTM HUCPVCs) are a highly promising candidate due to their pericyte-like properties, high proliferative and multilineage potential, immune-privileged properties, and robust paracrine profile. To effectively evaluate potentially angiogenic regenerative cells, it is a requisite to test them in reliable and &#34;translatable&#34; pre-clinical assays. The aortic ring assay is an ex vivo angiogenesis model that allows for easy quantification of tubular endothelial structures, provides accessory supportive cells and extracellular matrix (ECM) from the host, excludes inflammatory components, and is fast and inexpensive to set up. This is advantageous when compared to in vivo models (e.g., corneal assay, Matrigel plug assay); the aortic ring assay can track the administered cells and observe intercellular interactions while avoiding xeno-immune rejection.
We present a protocol for a novel application of the aortic ring assay, which includes human MSCs in co-cultures with developing rat aortic endothelial networks. This assay allows for the analysis of the MSC contribution to tube formation and development through physical pericyte-like interactions and of their potency for actively migrating to sites of angiogenesis, and for evaluating their ability to perform and mediate ECM processing. This protocol provides further information on changes in MSC phenotype and gene expression following co-culture.

The Aortic Ring Co-culture Assay: A Convenient Tool to Assess the Angiogenic Potential of Mesenchymal Stromal Cells In Vitro

Here, we present a novel application of the aortic ring assay where prelabelled mesenchymal cells are co-cultured with rat aorta-derived endothelial networks. This novel method allows visualization of Mesenchymal Stromal Cells (MSCs) homing and integration with endothelial networks, quantification of network properties, and evaluation of MSC immunophenotypes and gene expression.

Angiogenesis is a complex, highly regulated process responsible for providing and maintaining adequate tissue perfusion. Insufficient vasculature ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Isolation of Human Endometrial Stromal Cells for In Vitro Decidualization

The differentiation of human endometrial stromal cells (HESC) from fibroblast-like appearance into secretory decidua is a transformation required for embryo implantation into the uterine lining of the maternal womb. Improper decidualization has been established as a root cause for implantation failure and subsequent early embryo miscarriage. Therefore, understanding the molecular mechanisms underlying decidualization is advantageous to improving the rate of successful births. In vivo based studies of artificial decidualization are often limiting due to ethical dilemmas associated with human research, as well as translational complications within animal models. As a result, in vitro assays through primary cell culture are often utilized to explore the modulation of decidualization via hormones. This study provides a detailed protocol for the isolation of HESC and subsequent artificial decidualization via the supplementation of hormones to the culturing medium. Further, this study provides a well-designed method to knockdown any gene of interest by utilizing lipid-based siRNA transfections. This protocol permits the optimization of culture purity as well as product yield, thereby maximizing the ability to utilize this model as a reliable method to understand the molecular mechanisms underlying decidualization, and the subsequent quantification of secreted agents by decidualized endometrial stromal cells.

Isolation of Human Endometrial Stromal Cells for In Vitro Decidualization

This study presents a validated and optimized procedure for the isolation and culture of human endometrial stromal cells to conduct in vitro decidualization assay. Further, this study provides a detailed method to efficiently knockdown a specific gene using siRNAs in human endometrial stromal cells.

The differentiation of human endometrial stromal cells (HESC) from fibroblast-like appearance into secretory decidua is a transformation required for ...

A Cell-based Assay to Investigate Non-muscle Myosin II Contractility via the Folded-gastrulation Signaling Pathway in Drosophila S2R+ Cells

We have developed a cell-based assay using Drosophila cells that recapitulates apical constriction initiated by folded gastrulation (Fog), a secreted epithelial morphogen. In this assay, Fog is used as an agonist to activate Rho through a signaling cascade that includes a G-protein-coupled receptor (Mist), a G&#945;12/13 protein (Concertina/Cta), and a PDZ-domain-containing guanine nucleotide exchange factor (RhoGEF2). Fog signaling results in the rapid and dramatic reorganization of the actin cytoskeleton to form a contractile purse string. Soluble Fog is collected from a stable cell line and applied ectopically to S2R+ cells, leading to morphological changes like apical constriction, a process observed during developmental processes such as gastrulation. This assay is amenable to high-throughput screening and, using RNAi, can facilitate the identification of additional genes involved in this pathway.

A Cell-based Assay to Investigate Non-muscle Myosin II Contractility via the Folded-gastrulation Signaling Pathway in Drosophila S2R+ Cells

Here we describe a contractility assay using Drosophila S2R+ cells. The application of an exogenous ligand, folded gastrulation (Fog), leads to the activation of the Fog signaling pathway and cellular contractility. This assay can be used to investigate the regulation of cellular contractility proteins in the Fog signaling pathway.

We have developed a cell-based assay using Drosophila cells that recapitulates apical constriction initiated by folded gastrulation (Fog), a secreted ...