Name: formation of human periodontal ligament cell spheroids on chitosan films
Uploaded: 2019-06-19T15:00:00
Description: Watch this Scientific Journal Video about Formation of Human Periodontal Ligament Cell Spheroids on Chitosan Films at JoVE.com

This study was sponsored by National Natural Science Foundation of China (NSFC 81700978), Fundamental Research Funds for the Central Universities (1504219050), Natural Science Foundation of Shanghai (17ZR1432800), and Shanghai Medical Exploration Project (17411972600).

The study protocol was approved by the Ethics Committee of School and Hospital of Stomatology, Tongji University. All patients provided written informed consent.
1. PDL cell isolation
<ol>
	<li>Make proliferation medium for culture of PDL cells: &#945;-MEM medium supplemented with 10% FCS and 100 U/mL pen/strep.</li>
	<li>Prepare a container with ice to transfer isolated third molars.</li>
	<li>Sterilize surgical instruments by using an autoclave.</li>
	<li>Extract normal human impacted thir...

<ol>
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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-Based+Approaches+in+Periodontal+Regeneration:+A+Systematic+Review+and+Meta-Analysis+of+Periodontal+Defect+Models+in+Animal+Experimental+Work.">Cell-Based Approaches in Periodontal Regeneration: A Systematic Review and Meta-Analysis of Periodontal Defect Models in Animal Experimental Work.</a> Tissue Engineering Part B Review. 21 (5), 411-426 (2015).</li><li>Itaya, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristic+changes+of+periodontal+ligament-derived+cells+during+passage.">Characteristic changes of periodontal ligament-derived cells during passage.</a> Journal of Periodontal Research. 44 (4), 425-433 (2009).</li><li>Zhang, J., Li, B., Wang, J. 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+role+of+engineered+tendon+matrix+in+the+stemness+of+tendon+stem+cells+in+vitro+and+the+promotion+of+tendon-like+tissue+formation+in+vivo.">The role of engineered tendon matrix in the stemness of tendon stem cells in vitro and the promotion of tendon-like tissue formation in vivo.</a> Biomaterials. 32 (29), 6972-6981 (2011).</li><li>Elliott, N. T., Yuan, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+three-dimensional+in+vitro+tissue+models+for+drug+discovery+and+transport+studies.">A review of three-dimensional in vitro tissue models for drug discovery and transport studies.</a> Journal of Pharmaceutical Sciences. 100 (1), 59-74 (2011).</li><li>Fennema, E., Rivron, N., Rouwkema, J., van Blitterswijk, C., de Boer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spheroid+culture+as+a+tool+for+creating+3D+complex+tissues.">Spheroid culture as a tool for creating 3D complex tissues.</a> Trends in Biotechnology. 31 (2), 108-115 (2013).</li><li>Cheng, N. C., Wang, S., Young, T. 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+influence+of+spheroid+formation+of+human+adipose-derived+stem+cells+on+chitosan+films+on+stemness+and+differentiation+capabilities.">The influence of spheroid formation of human adipose-derived stem cells on chitosan films on stemness and differentiation capabilities.</a> Biomaterials. 33 (6), 1748-1758 (2012).</li><li>Yeh, Y. 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=Cardiac+repair+with+injectable+cell+sheet+fragments+of+human+amniotic+fluid+stem+cells+in+an+immune-suppressed+rat+model.">Cardiac repair with injectable cell sheet fragments of human amniotic fluid stem cells in an immune-suppressed rat model.</a> Biomaterials. 31 (25), 6444-6453 (2010).</li><li>Kabiri, M., 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=3D+mesenchymal+stem/stromal+cell+osteogenesis+and+autocrine+signalling.">3D mesenchymal stem/stromal cell osteogenesis and autocrine signalling.</a> Biochemical and Biophysical Research Communications. 419 (2), 142-147 (2012).</li><li>Lee, J. H., Han, Y. S., Lee, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-Duration+Three-Dimensional+Spheroid+Culture+Promotes+Angiogenic.">Long-Duration Three-Dimensional Spheroid Culture Promotes Angiogenic.</a> Activities of Adipose-Derived Mesenchymal Stem Cells. Biomolecules &amp; therapeutics. 24 (3), 260-267 (2016).</li><li>Yan, X. Z., van den Beucken, J., Yuan, C., Jansen, J. A., Yang, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spheroid+formation+and+stemness+preservation+of+human+periodontal+ligament+cells+on+chitosan+films.">Spheroid formation and stemness preservation of human periodontal ligament cells on chitosan films.</a> Oral Diseases. 24 (6), 1083-1092 (2018).</li><li>Meli, L., Jordan, E. T., Clark, D. S., Linhardt, R. J., Dordick, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+a+three-dimensional,+microarray+environment+on+human+Cell+culture+in+drug+screening+systems.">Influence of a three-dimensional, microarray environment on human Cell culture in drug screening systems.</a> Biomaterials. , (2012).</li><li>LaRue, K. E., Khalil, M., Freyer, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microenvironmental+regulation+of+proliferation+in+multicellular+spheroids+is+mediated+through+differential+expression+of+cyclin-dependent+kinase+inhibitors.">Microenvironmental regulation of proliferation in multicellular spheroids is mediated through differential expression of cyclin-dependent kinase inhibitors.</a> Cancer Research. 64 (5), 1621-1631 (2004).</li><li>Tsai, A. C., Liu, Y., Yuan, X., Ma, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compaction,+fusion,+and+functional+activation+of+three-dimensional+human+mesenchymal+stem+cell+aggregate.">Compaction, fusion, and functional activation of three-dimensional human mesenchymal stem cell aggregate.</a> Tissue Engineering Part A. 21 (9-10), 1705-1719 (2015).</li><li>Cesarz, Z., Tamama, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spheroid+Culture+of+Mesenchymal+Stem+Cells.">Spheroid Culture of Mesenchymal Stem Cells.</a> Stem Cells International. 2016, 9176357 (2016).</li><li>Tong, J. Z., Sarrazin, S., Cassio, D., Gauthier, F., Alvarez, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+spheroid+culture+to+human+hepatocytes+and+maintenance+of+their+differentiation.">Application of spheroid culture to human hepatocytes and maintenance of their differentiation.</a> Biology of the Cell. 81 (1), 77-81 (1994).</li><li>Lee, W. Y., 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=The+use+of+injectable+spherically+symmetric+cell+aggregates+self-assembled+in+a+thermo-responsive+hydrogel+for+enhanced+cell+transplantation.">The use of injectable spherically symmetric cell aggregates self-assembled in a thermo-responsive hydrogel for enhanced cell transplantation.</a> Biomaterials. 30 (29), 5505-5513 (2009).</li><li>Frith, J. E., Thomson, B., Genever, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+three-dimensional+culture+methods+enhance+mesenchymal+stem+cell+properties+and+increase+therapeutic+potential.">Dynamic three-dimensional culture methods enhance mesenchymal stem cell properties and increase therapeutic potential.</a> Tissue Engineering Part C Methods. 16 (4), 735-749 (2010).</li><li>Wang, 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=3D+spheroid+culture+system+on+micropatterned+substrates+for+improved+differentiation+efficiency+of+multipotent+mesenchymal+stem+cells.">3D spheroid culture system on micropatterned substrates for improved differentiation efficiency of multipotent mesenchymal stem cells.</a> Biomaterials. 30 (14), 2705-2715 (2009).</li><li>Miyagawa, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microfabricated+scaffold+induces+the+spheroid+formation+of+human+bone+marrow-derived+mesenchymal+progenitor+cells+and+promotes+efficient+adipogenic+differentiation.">A microfabricated scaffold induces the spheroid formation of human bone marrow-derived mesenchymal progenitor cells and promotes efficient adipogenic differentiation.</a> Tissue Engineering Part A. 17 (3-4), 513-521 (2011).</li><li>Bartosh, T. J., 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=Aggregation+of+human+mesenchymal+stromal+cells+(MSCs)+into+3D+spheroids+enhances+their+antiinflammatory+properties.">Aggregation of human mesenchymal stromal cells (MSCs) into 3D spheroids enhances their antiinflammatory properties.</a> Proceedings of the National Academy of Sciences of the United States of America. 107 (31), 13724-13729 (2010).</li><li>Baraniak, P. R., McDevitt, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scaffold-free+culture+of+mesenchymal+stem+cell+spheroids+in+suspension+preserves+multilineage+potential.">Scaffold-free culture of mesenchymal stem cell spheroids in suspension preserves multilineage potential.</a> Cell and Tissue Research. 347 (3), 701-711 (2012).</li><li>Rabea, E. I., Badawy, M. E., Stevens, C. 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The present study introduced a 3D cell culture system to overcome some limitations related to conventional 2D monolayer cell culture. According to the protocol, PDL cellular spheroids were successfully formed by culturing cells on chitosan films. Our previous study reported that spheroid formation increased the self-renewal and osteogenic differentiation capacities of PDL cells14. Instead of using an enzyme to harvest cells from TCPS, PDL cell spheroids could be harvested from chitosan films by si...

Periodontitis, initialized principally by dental plaque1, is characterized by the damage of periodontal tissues including periodontal ligament (PDL), alveolar bone, and cementum. Current treatments for periodontitis are usually successful in preventing the progress of the active disease, but the regeneration of lost periodontal tissues remains a clinical challenge. Recently, important progress has been made in cell-based approaches for periodontal tissue regeneration to overcome the drawbacks of current treatments2,3,4.
Our previous systematic review revealed that PDL cells showed great potential for periodontal regeneration5. Conventionally, PDL cells are cultured on two-dimensional (2D) substrates such as tissue culture polystyrene (TCPS). However, characteristic changes of PDL cells have been observed during in vitro culture6. This phenomenon is probably because the 2D TCPS differs from the in vivo three-dimensional (3D) microenvironment7. Compared to cells cultured on 2D substrates, cells grown in a 3D microenvironment exhibit more similarities to in vivo cells8. Therefore, 3D cell culture models provide a promising alternative for conventional 2D monolayer cell culture.
Conventional 3D culture method is encapsulating cells in 3D biomaterials. Compared with cells encapsulated in 3D biomaterials, cellular spheroids mimic the in vivo situation more closely because spheroids are aggregates of cells growing free of foreign materials9,10,11,12. It is reported that cellular spheroids promoted MSC bioactivities via the preservation of extracellular matrix (ECM) components including fibronectin and laminin13. To improve conventional PDL cell culture models, we have recently developed a 3D PDL cell culture method, which is based on spheroid formation of PDL cells on chitosan films14. Spheroid formation increased the self-renewal and osteogenic differentiation capacities of PDL cells14. Here, we present detailed PDL cell spheroid culture protocols based on chitosan films. The 3D culture system of PDL cellular spheroids overcome some of the shortcomings related to conventional TCPS cell culture, and thus may be suitable for producing PDL cells with an enhanced therapeutic efficacy for future periodontal tissue regeneration.

<table border="0" cellpadding="0" cellspacing="0" style="width:718px;" width="718">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">&#945;-MEM</td>
			<td style="width:158px;">Gibco</td>
			<td style="width:166px;">11900-073</td>
			<td style="width:172px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">acetic acid&#160;</td>
			<td style="width:158px;">Sigma-Aldrich</td>
			<td style="width:166px;">64197</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Cell culture flask 25 cm2</td>
			<td style="width:158px;">Corning</td>
			<td style="width:166px;">430639</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Cell culture flask 75 cm2</td>
			<td style="width:158px;">Corning</td>
			<td style="width:166px;">430641</td>
			<td></td>
		</tr>
		<tr height="62">
			<td height="62" style="height:63px;width:223px;">Chitosan</td>
			<td style="width:158px;">Heppe Medical&#160;Chitosan GmbH</td>
			<td style="width:166px;">/</td>
			<td>molecular weight 500 kDa, degree of deacetylation 85%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">FCS</td>
			<td style="width:158px;">Gibco</td>
			<td style="width:166px;">26140-079</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:223px;">Live/Dead Viability/Cytotoxicity Kit</td>
			<td style="width:158px;">Molecular&#160;Probes</td>
			<td style="width:166px;">L3224</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">NaOH</td>
			<td style="width:158px;">Sigma-Aldrich</td>
			<td style="width:166px;">1310732</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">PBS</td>
			<td>KeyGen Biotech&#160;</td>
			<td style="width:166px;">KGB5001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">pen/strep</td>
			<td style="width:158px;">Gibco</td>
			<td style="width:166px;">15140-122</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Trypsin/EDTA&#160;</td>
			<td>KeyGen Biotech&#160;</td>
			<td style="width:166px;">KGM25200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">15 mL conical centrifuge tube</td>
			<td style="width:158px;">Corning</td>
			<td style="width:166px;">430790</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">24-well plate</td>
			<td style="width:158px;">Corning</td>
			<td style="width:166px;">3524</td>
			<td></td>
		</tr>
	</tbody>
</table>

formation of human periodontal ligament cell spheroids on chitosan films

Periodontal ligament (PDL) cells hold great promise for periodontal tissue regeneration. Conventionally, PDL cells are cultured on two-dimensional (2D) substrates such as tissue culture polystyrene (TCPS). However, characteristic changes of PDL cells have been observed during in vitro culture. This phenomenon is probably because the 2D TCPS differs from the in vivo three-dimensional (3D) microenvironment. Compared to cells cultured on 2D substrates, cells grown in a 3D microenvironment exhibit more similarities to in vivo cells. Therefore, 3D cell culture models provide a promising alternative for conventional 2D monolayer cell culture. To improve conventional PDL cell culture models, we have recently developed a 3D cell culture method, which is based on spheroid formation of PDL cells on chitosan films. Here, we present detailed cell spheroid culture protocols based on chitosan films. The 3D culture system of PDL cellular spheroids overcome some of the limitations related to conventional 2D monolayer cell culture, and thus may be suitable for producing PDL cells with an enhanced therapeutic efficacy for future periodontal tissue regeneration.

Using the present protocol, viable PDL cell spheroids were successfully formed. Figure 1 showed that suspended cells or spheroids instead of attached cells were mainly observed on chitosan films. For the seeding density of 0.5 x 104 cells/cm2, attached PDL cells were occasionally found on day 1 and 3, and PDL cell spheroids were rarely observed. On the contrary, for the seeding densities of 3 x 104 and 6 x 104 cells...

Watch this Scientific Journal Video about Formation of Human Periodontal Ligament Cell Spheroids on Chitosan Films at JoVE.com

Formation of Human Periodontal Ligament Cell Spheroids on Chitosan Films

Here, we present protocols of culturing human periodontal ligament (PDL) cell spheroids by chitosan films. The culture of three-dimensional (3D) cellular spheroids provides an alternative to conventional tissue culture polystyrene (TCPS) culture system.

Periodontal ligament (PDL) cells hold great promise for periodontal tissue regeneration. Conventionally, PDL cells are cultured on two-dimensional (2D) ...

This is a detailed protocol of culturing periodontal ligament cell spheroids by chitosan films. Compared with the conventional culture system, the spheroid culture system produces periodontal ligament cells with increased self-renewal and osteogenic differentiation abilities. To begin, prepare 1%weight-to-volume chitosan solution as directed in the manuscript.Add 0.5 milliliters of chitosan solution into each well of a 24-well tissue culture polystyrene plate. Dry the plate in an oven at 60 degrees Celsius for 24 hours to form chitosan films. To neutralize the chitosan films, add 0.5 milliliters of 0.5 normal sodium hydroxide to each well of the 24-well plate and incubate at room temperature for two hours.Then, wash the chitosan films three times with double-distilled water. Sterilize the chitosan-coated 24-well plate in 70%alcohol overnight at room temperature. Rinse the plate three times with PBS then leave it under ultraviolet light overnight.Prior to cell seeding, pre-warm proliferation medium, PBS solution, and trypsin EDTA solution to 37 degrees Celsius. Discard the supernatant from the cell culture flask and wash the confluent periodontal ligament, or PDL cells, with 10 milliliters of PBS. Discard the PBS and add one milliliter of trypsin EDTA solution to the flask.Incubate the flask at 37 degrees Celsius for three minutes and then add three milliliters of proliferation medium to terminate the trypsin digestion. Transfer the cell suspension to a 15 milliliter conical tube then centrifuge it for five minutes at 300 times g. Discard the supernatant and re-suspend the cells in 500 microliters of proliferation medium.Count the cells with a hemocytometer and seed them onto the plate at five, 10, 30, and 60 thousand cells per square centimeter. Culture the PDL cells in an incubator at 37 degrees Celsius in 5%carbon dioxide and humidified air, changing the culture medium twice per week. Observe cell morphology daily for five days via an inverse phase contrast microscope.Viable PDL cell spheroids are successfully formed using this protocol. Spheroids are rarely observed for the lower-seeding density on days one and three. But at the two higher densities, various sizes of spheroids are present from day one.The optimal seeding density is 30 thousand cells per centimeter squared because it results in homogeneous spheroids. After five days of culture, larger spheroids are observed for all seeding densities. A viability assay demonstrates that the majority of PDL cells are alive on days one, three, and six, but the number of dead cells increases on day six.One limitation of this protocol is the decreased proliferation of cells after spheroid formation. So further studies to promote the proliferation of cells after spheroid formation are required.

formation-human-periodontal-ligament-cell-spheroids-on-chitosan

Research

JoVE Journal

Developmental Biology

Isolation and Quantitative Immunocytochemical Characterization of Primary Myogenic Cells and Fibroblasts from Human Skeletal Muscle

The repair and regeneration of skeletal muscle requires the action of satellite cells, which are the resident muscle stem cells. These can be isolated from human muscle biopsy samples using enzymatic digestion and their myogenic properties studied in culture. Quantitatively, the two main adherent cell types obtained from enzymatic digestion are: (i) the satellite cells (termed myogenic cells or muscle precursor cells), identified initially as CD56+ and later as CD56+/desmin+ cells and (ii) muscle-derived fibroblasts, identified as CD56&#8211; and TE-7+. Fibroblasts proliferate very efficiently in culture and in mixed cell populations these cells may overrun myogenic cells to dominate the culture. The isolation and purification of different cell types from human muscle is thus an important methodological consideration when trying to investigate the innate behavior of either cell type in culture. Here we describe a system of sorting based on the gentle enzymatic digestion of cells using collagenase and dispase followed by magnetic activated cell sorting (MACS) which gives both a high purity (&#62;95% myogenic cells) and good yield (~2.8 x 106 &#177; 8.87 x 105 cells/g tissue after 7 days in vitro) for experiments in culture. This approach is based on incubating the mixed muscle-derived cell population with magnetic microbeads beads conjugated to an antibody against CD56 and then passing cells though a magnetic field. CD56+ cells bound to microbeads are retained by the field whereas CD56&#8211; cells pass unimpeded through the column. Cell suspensions from any stage of the sorting process can be plated and cultured. Following a given intervention, cell morphology, and the expression and localization of proteins including nuclear transcription factors can be quantified using immunofluorescent labeling with specific antibodies and an image processing and analysis package.

The main adherent cell types derived from human muscle are myogenic cells and fibroblasts. Here, cell populations are enriched using magnetic-activated cell sorting based on the CD56 antigen. Subsequent immunolabelling with specific antibodies and use of image analysis techniques allows quantification of cytoplasmic and nuclear characteristics in individual cells.

The repair and regeneration of skeletal muscle requires the action of satellite cells, which are the resident muscle stem cells. These can be isolated ...

Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes

Neural stem cells (NSCs) are capable of self-renewal and differentiation into neurons, astrocytes and oligodendrocytes under specific local microenvironments. In here, we present a set of methods used for three dimensional (3D) differentiation and miRNA analysis of a clonal human neural stem cell (hNSC) line, currently in clinical trials for stroke disability (NCT01151124 and NCT02117635, Clinicaltrials.gov). HNSCs were derived from an ethical approved first trimester human fetal cortex and conditionally immortalized using retroviral integration of a single copy of the c-mycERTAMconstruct. We describe how to measure axon process outgrowth of hNSCs differentiated on 3D scaffolds and how to quantify associated changes in miRNA expression using PCR array. Furthermore we exemplify computational analysis with the aim of selecting miRNA putative targets. SOX5 and NR4A3 were identified as suitable miRNA putative target of selected significantly down-regulated miRNAs in differentiated hNSC. MiRNA target validation was performed on SOX5 and NR4A3 3&#8217;UTRs by dual reporter plasmid transfection and dual luciferase assay.

With the intent of characterizing changes in miRNAs on differentiated human neural stem cells (hNSCs) we describe hNSC differentiation on a three dimensional system,the evaluation of changes in microRNA expression by miRNA PCR array, and computational analysis for miRNA target prediction and its validation by dual luciferase assay.

Neural stem cells (NSCs) are capable of self-renewal and differentiation into neurons, astrocytes and oligodendrocytes under specific local ...

A Novel Culture Model for Human Pluripotent Stem Cell Propagation on Gelatin in Placenta-conditioned Media

The propagation of human pluripotent stem cells (hPSCs) in conditioned medium derived from human cells in feeder-free culture conditions has been of interest. Nevertheless, an ideal humanized ex vivo feeder-free propagation method for hPSCs has not been developed; currently, additional exogenous substrates including basic fibroblast growth factor (bFGF), a master hPSC-sustaining factor, is added to all of culture media and synthetic substrata such as Matrigel or laminin are used in all feeder-free cultures. Recently, our group developed a simple and efficient protocol for the propagation of hPSCs using only conditioned media derived from the human placenta on a gelatin-coated dish without additional exogenous supplementation or synthetic substrata specific to hPSCs. This protocol has not been reported previously and might enable researchers to propagate hPSCs efficiently in humanized culture conditions. Additionally, this model obviates hPSC contamination risks by animal products such as viruses or unknown proteins. Furthermore, this system facilitates easy mass production of hPSCs using the gelatin coating, which is simple to handle, dramatically decreases the overall costs of ex vivo hPSC maintenance.

This protocol provides a simple and efficient way to propagate human pluripotent stem cells (hPSCs) using only conditioned media derived from the human placenta in a gelatin-coated dish without additional exogenous supplementation or hPSC-specific synthetic substrata.

The propagation of human pluripotent stem cells (hPSCs) in conditioned medium derived from human cells in feeder-free culture conditions has been of ...

Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis

Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function and physiology of their in vivo tissue counterparts. This is exemplified by organotypic skin cultures which faithfully recapitulates the epidermal differentiation and stratification program. Primary human epidermal keratinocytes are genetically manipulable through retroviruses where genes can be easily overexpressed or knocked down. These genetically modified keratinocytes can then be used to regenerate human epidermis in organotypic skin cultures providing a powerful model to study genetic pathways impacting epidermal growth, differentiation, and disease progression. The protocols presented here describe methods to prepare devitalized human dermis as well as to genetically manipulate primary human keratinocytes in order to generate organotypic skin cultures. Regenerated human skin can be used in downstream applications such as gene expression profiling, immunostaining, and chromatin immunoprecipitations followed by high throughput sequencing. Thus, generation of these genetically modified organotypic skin cultures will allow the determination of genes that are critical for maintaining skin homeostasis.

The goal of this paper is to provide a comprehensive and detailed protocol on how to generate genetically modified human organotypic skin from epidermal keratinocytes and devitalized human dermis.

Organotypic cultures allow the reconstitution of a 3D environment critical for cell-cell contact and cell-matrix interactions which mimics the function ...

A RANKL-based Osteoclast Culture Assay of Mouse Bone Marrow to Investigate the Role of mTORC1 in Osteoclast Formation

Osteoclasts are unique bone-resorbing cells that differentiate from the monocyte/macrophage lineage of bone marrow. Dysfunction of osteoclasts may result in a series of bone metabolic diseases, including osteoporosis. To develop pharmaceutical targets for the prevention of pathological bone mass loss, the mechanisms by which osteoclasts differentiate from precursors must be understood. The ability to isolate and culture a large number of osteoclasts in vitro is critical in order to determine the role of specific genes in osteoclast differentiation. Inactivation of the mammalian/mechanistic target of rapamycin complex 1 (TORC1) in osteoclasts can decrease osteoclast number and increase bone mass; however, the underlying mechanisms require further study. In the present study, a RANKL-based protocol to isolate and culture osteoclasts from mouse bone marrow and to study the influence of mTORC1 inactivation on osteoclast formation is described. This protocol successfully resulted in a large number of giant osteoclasts, typically within one week. Deletion of Raptor impaired osteoclast formation and decreased the activity of secretory tartrate-resistant acid phosphatase, indicating that mTORC1 is critical for osteoclast formation.

This manuscript describes a protocol to isolate and culture osteoclasts in vitro from mouse bone marrow, and to study the role of the mammalian/mechanistic target of rapamycin complex 1 in osteoclast formation.

Osteoclasts are unique bone-resorbing cells that differentiate from the monocyte/macrophage lineage of bone marrow. Dysfunction of osteoclasts may result ...

HUVEC Tube-formation Assay to Evaluate the Impact of Natural Products on Angiogenesis

Angiogenesis is a phenomenon that includes different processes, such as endothelial cell proliferation, differentiation, and migration, that lead to the formation of new blood vessels and involve several signal transduction pathways. Here we show that the tube formation assay is a simple in vitro method to evaluate the impact of natural products on angiogenesis and to investigate the molecular mechanisms involved. In particular, in the presence of the water extract of Ruta graveolens (RGWE), endothelial cells are no longer able to form a cell-cell network and that the RGWE effects on human umbilical vein endothelial cell (HUVEC) tube formation is abolished by the constitutive activation of MEK.

Here, we evaluate the effects of the water extract of Ruta graveolens on vessel network formation by using a tube formation assay on a gelled basement matrix.

Angiogenesis is a phenomenon that includes different processes, such as endothelial cell proliferation, differentiation, and migration, that lead to the ...

Efficient Differentiation of Human Pluripotent Stem Cells into Liver Cells

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver failure&#8212;which can be caused by chronic alcohol intake, hepatitis, acute poisoning, or other insults&#8212;is a severe condition that can culminate in bleeding, jaundice, coma, and eventually death. However, approaches to treat liver failure, as well as studies of liver function and disease, have been stymied in part by the lack of a plentiful supply of human liver cells. To this end, this protocol details the efficient differentiation of human pluripotent stem cells (hPSCs) into hepatocyte-like cells, guided by a developmental roadmap that describes how liver fate is specified across six consecutive differentiation steps. By manipulating developmental signaling pathways to promote liver differentiation and to explicitly suppress the formation of unwanted cell fates, this method efficiently generates populations of human liver bud progenitors and hepatocyte-like cells by days 6 and 18 of PSC differentiation, respectively. This is achieved through the temporally-precise control of developmental signaling pathways, exerted by small molecules and growth factors in a serum-free culture medium. Differentiation in this system occurs in monolayers and yields hepatocyte-like cells that express characteristic hepatocyte enzymes and have the ability to engraft a mouse model of chronic liver failure. The ability to efficiently generate large numbers of human liver cells in vitro has ramifications for treatment of liver failure, for drug screening, and for mechanistic studies of liver disease.

This protocol details a monolayer, serum-free method to efficiently generate hepatocyte-like cells from human pluripotent stem cells (hPSCs) in 18 days. This entails six steps as hPSCs sequentially differentiate into intermediate cell-types such as the primitive streak, definitive endoderm, posterior foregut and liver bud progenitors before forming hepatocyte-like cells.

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver ...

Hemogenic Reprogramming of Human Fibroblasts by Enforced Expression of Transcription Factors

The cellular and molecular mechanisms underlying specification of human hematopoietic stem cells (HSCs) remain elusive. Strategies to recapitulate human HSC emergence in vitro are required to overcome limitations in studying this complex developmental process. Here, we describe a protocol to generate hematopoietic stem and progenitor-like cells from human dermal fibroblasts employing a direct cell reprogramming approach. These cells transit through a hemogenic intermediate cell-type, resembling the endothelial-to-hematopoietic transition (EHT) characteristic of HSC specification. Fibroblasts were reprogrammed to hemogenic cells via transduction with GATA2, GFI1B and FOS transcription factors. This combination of three factors induced morphological changes, expression of hemogenic and hematopoietic markers and dynamic EHT transcriptional programs. Reprogrammed cells generate hematopoietic progeny and repopulate immunodeficient mice for three months. This protocol can be adapted towards the mechanistic dissection of the human EHT process as exemplified here by defining GATA2 targets during the early phases of reprogramming. Thus, human hemogenic reprogramming provides a simple and tractable approach to identify novel markers and regulators of human HSC emergence. In the future, faithful induction of hemogenic fate in fibroblasts may lead to the generation of patient-specific HSCs for transplantation.

This protocol demonstrates the induction of a hemogenic program in human dermal fibroblasts by enforced expression of the transcription factors GATA2, GFI1B and FOS to generate hematopoietic stem and progenitor cells.

The cellular and molecular mechanisms underlying specification of human hematopoietic stem cells (HSCs) remain elusive. Strategies to recapitulate human ...

Eye Removal in Living Zebrafish Larvae to Examine Innervation-dependent Growth and Development of the Visual System

Zebrafish exhibit remarkable life-long growth and regenerative abilities. For example, specialized stem cell niches established during embryogenesis support continuous growth of the entire visual system, both in the eye and the brain. Coordinated growth between the retinae and the optic tectum ensures accurate retinotopic mapping as new neurons are added in the eyes and brain. To address whether retinal axons provide crucial information for regulating tectal stem and progenitor cell behaviors such as survival, proliferation, and/or differentiation, it is necessary to be able to compare innervated and denervated tectal lobes within the same animal and across animals. 
Surgical removal of one eye from living larval zebrafish followed by observation of the optic tectum achieves this goal. The accompanying video demonstrates how to anesthetize larvae, electrolytically sharpen tungsten needles, and use them to remove one eye. It next shows how to dissect brains from fixed zebrafish larvae. Finally, the video provides an overview of the protocol for immunohistochemistry and a demonstration of how to mount stained embryos in low-melting-point agarose for microscopy.

The article explains how to surgically remove eyes from living zebrafish larvae as the first step toward investigating how retinal input influences optic tectum growth and development. In addition, the article provides information about larval anesthetization, fixation, and brain dissection, followed by immunohistochemistry and confocal imaging.

Zebrafish exhibit remarkable life-long growth and regenerative abilities. For example, specialized stem cell niches established during embryogenesis ...

Gene Expression Analyses in Human Follicles

The ovary is a heterogeneous organ composed of different cell types. To study the molecular mechanisms occurring during folliculogenesis, the localization of proteins and gene expression can be performed on fixed tissue. However, to properly assess gene expression levels in a human follicle, this complex and delicate structure must be isolated. Hence, an adapted protocol previously described by Woodruff&#39;s laboratory has been developed to separate follicles (the oocyte and the granulosa cells) from their surrounding environment. The ovarian cortical tissue is first manually processed to obtain small fragments using two tools: a tissue slicer and a tissue chopper. The tissue is then enzymatically digested with 0.2% collagenase and 0.02% DNase for at least 40 min. This digestion step is performed at 37 &#176;C and 5% CO2 and is accompanied by mechanical pipetting of the medium every 10 min. After incubation, the isolated follicles are collected manually using a calibrated microcapillary pipette under microscope magnification. If follicles are still present in the pieces of tissue, the procedure is completed with manual microdissection. The follicles are collected on ice in a culture medium and are rinsed twice in droplets of phosphate-buffered saline solution. This digestion procedure must be carefully controlled to avoid follicle deterioration. As soon as the structure of the follicles appears to be compromised or after a maximum of 90 min, the reaction is stopped with a 4 &#176;C blocking solution containing 10% fetal bovine serum. A minimum of 20 isolated follicles (sized under 75 &#181;m) should be collected to obtain an adequate amount of total RNA after RNA extraction for real-time quantitative polymerase chain reaction (RT-qPCR). After extraction, the quantification of total RNA from 20 follicles reaches a mean value of 5 ng/&#181;L. The total RNA is then retrotranscribed into cDNA, and the genes of interest are further analyzed using RT-qPCR.

Here, we describe a protocol outlining how to isolate human ovarian follicles from frozen-thawed cortical tissue to perform gene expression analyses.

The ovary is a heterogeneous organ composed of different cell types. To study the molecular mechanisms occurring during folliculogenesis, the localization ...