Name: a simplified and efficient method to isolate primary human keratinocytes from adult skin tissue
Uploaded: 2018-08-25T13:00:00
Description: Watch this Scientific Journal Video about A Simplified and Efficient Method to Isolate Primary Human Keratinocytes from Adult Skin Tissue at JoVE.com

This work was supported by the National Key Research and Development Program of China (2017YFA0104604), the General Program of National Natural Science Foundation of China (NSFC, 81772093), the Science and Technology Development Program of Suzhou (ZXL2015128), the Natural Science Foundation of Jiangsu Province (BK20161241), and a Shandong Taishan Scholar Award (tshw201502065).

Human tissues used in this protocol have been handled according to the guidelines of the Institution&#39;s human research ethics committee (NO.2015120401, date: May 12, 2015).
1. Preparations
<ol>
	<li>Collect fresh adult abdominal skin tissues discarded from plastic surgery at the hospital in a 50-mL tube with 10 mL of ice-cold Dulbecco&#39;s modified Eagle medium (DMEM). The specimen can be kept at 4 &#176;C for up to 72 h without significantly affecting the cell viability.</li>
	<li>Prepa...

<ol>
	<li>Ojeh, N., Pastar, I., Tomic-Canic, M., Stojadinovic, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+Cells+in+Skin+Regeneration,+Wound+Healing,+and+Their+Clinical+Applications.">Stem Cells in Skin Regeneration, Wound Healing, and Their Clinical Applications.</a> International Journal of Molecular Sciences. 16 (10), 25476-25501 (2015).</li><li>Sotiropoulou, P. A., Blanpain, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+homeostasis+of+the+skin+epidermis.">Development and homeostasis of the skin epidermis.</a> Cold Spring Harbor Perspectives in BIology. 4 (7), a008383 (2012).</li><li>Kamstrup, M., Faurschou, A., Gniadecki, R., Wulf, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidermal+stem+cells+-+role+in+normal,+wounded+and+pathological+psoriatic+and+cancer+skin.">Epidermal stem cells - role in normal, wounded and pathological psoriatic and cancer skin.</a> Current Stem Cell Research &amp; Therapy. 3 (2), 146-150 (2008).</li><li>Blanpain, C., Fuchs, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidermal+stem+cells+of+the+skin.">Epidermal stem cells of the skin.</a> Annual Review of Cell and Developmental Biology. 22 (22), 339-373 (2006).</li><li>Guo, 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=Building+a+microphysiological+skin+model+from+induced+pluripotent+stem+cells.">Building a microphysiological skin model from induced pluripotent stem cells.</a> Stem Cell Research &amp; Therapy. 4 (S1), S2 (2013).</li><li>Aasen, T., Izpisua Belmonte, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+and+cultivation+of+human+keratinocytes+from+skin+or+plucked+hair+for+the+generation+of+induced+pluripotent+stem+cells.">Isolation and cultivation of human keratinocytes from skin or plucked hair for the generation of induced pluripotent stem cells.</a> Nature Protocols. 5 (2), 371-382 (2010).</li><li>Bayati, V., Abbaspour, M. R., Neisi, N., Hashemitabar, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skin-derived+precursors+possess+the+ability+of+differentiation+into+the+epidermal+progeny+and+accelerate+burn+wound+healing.">Skin-derived precursors possess the ability of differentiation into the epidermal progeny and accelerate burn wound healing.</a> Cell Biology International. 41 (2), 187-196 (2017).</li><li>Hirsch, 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=Regeneration+of+the+entire+human+epidermis+using+transgenic+stem+cells.">Regeneration of the entire human epidermis using transgenic stem cells.</a> Nature. 551 (7680), 327-332 (2017).</li><li>Hentzer, B., Kobayasi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Separation+of+human+epidermal+cells+from+fibroblasts+in+primary+skin+culture.">Separation of human epidermal cells from fibroblasts in primary skin culture.</a> Archiv f&#252;r dermatologische Forschung. 252 (1), 39-46 (1975).</li><li>Terunuma, A., Limgala, R. P., Park, C. J., Choudhary, I., Vogel, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+procurement+of+epithelial+stem+cells+from+human+tissue+specimens+using+a+Rho-associated+protein+kinase+inhibitor+Y-27632.">Efficient procurement of epithelial stem cells from human tissue specimens using a Rho-associated protein kinase inhibitor Y-27632.</a> Tissue Engineering Part A. 16 (4), 1363-1368 (2010).</li><li>Zhou, Q., 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=ROCK+inhibitor+Y-27632+increases+the+cloning+efficiency+of+limbal+stem/progenitor+cells+by+improving+their+adherence+and+ROS-scavenging+capacity.">ROCK inhibitor Y-27632 increases the cloning efficiency of limbal stem/progenitor cells by improving their adherence and ROS-scavenging capacity.</a> Tissue Engineering Part C: Methods. 19 (7), 531-537 (2013).</li><li>Kurosawa, H. <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+Rho-associated+protein+kinase+(ROCK)+inhibitor+to+human+pluripotent+stem+cells.">Application of Rho-associated protein kinase (ROCK) inhibitor to human pluripotent stem cells.</a> Journal of Bioscience and Bioengineering. 114 (6), 577-581 (2012).</li><li>Wen, J., Zu, T., Zhou, Q., Leng, X., Wu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Y-27632+simplifies+the+isolation+procedure+of+human+primary+epidermal+cells+by+selectively+blocking+focal+adhesion+of+dermal+cells.">Y-27632 simplifies the isolation procedure of human primary epidermal cells by selectively blocking focal adhesion of dermal cells.</a> Journal of Tissue Engineering and Regenerative Medicine. 12 (2), e1251-e1255 (2018).</li><li>Zou, D., Pan, J., Zhang, P., Wu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+to+isolate+human+epidermal+keratinocytes.">A new method to isolate human epidermal keratinocytes.</a> Journal of Clinical Dermatology (in Chinese). 6, 424-429 (2016).</li><li>Cerqueira, M. T., Frias, A. M., Reis, R. L., Marques, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interfollicular+epidermal+stem+cells:+boosting+and+rescuing+from+adult+skin).">Interfollicular epidermal stem cells: boosting and rescuing from adult skin).</a> Methods in Molecular Biology. 989, 1-9 (2013).</li><li>Candi, E., Schmidt, R., Melino, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cornified+envelope:+a+model+of+cell+death+in+the+skin.">The cornified envelope: a model of cell death in the skin.</a> Nature Reviews Molecular Cell Biology. 6 (4), 328-340 (2005).</li><li>Breyer, 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=Inhibition+of+Rho+kinases+increases+directional+motility+of+microvascular+endothelial+cells.">Inhibition of Rho kinases increases directional motility of microvascular endothelial cells.</a> Biochemical Pharmacology. 83 (5), 616-626 (2012).</li><li>Wozniak, M. A., Modzelewska, K., Kwong, L., Keely, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focal+adhesion+regulation+of+cell+behavior.">Focal adhesion regulation of cell behavior.</a> Biochimica et Biophysica Acta. 1692 (2-3), 103-119 (2004).</li></ol>

Cultured primary HKCs have been widely utilized to treat wounds in clinics for more than three decades and, since that time, it has been always important to efficiently obtain sufficient numbers of cells for clinical applications in a timely manner. Therefore, in practice, the conventional isolation method, which requires the separation of the epidermis from the dermis, makes it difficult to meet these demands, due to the low yield of cells and the low ability to passage adult cells. Here, we describe a new simple method...

The goal was to develop a simple and efficient protocol to isolate primary human keratinocytes (HKCs) from adult tissues, especially for clinical applications. Skin epidermal stem cells, localized in the basal layer of the skin, possess a high potential to proliferate and differentiate and provide keratinocytes to maintain the functions of the skin1,2,3,4. HKCs isolated from skin tissues are widely used for skin tissue engineering and regeneration purposes, especially in the repair of damaged skin and in gene therapy for clinical applications5,6. The key issue for HKC-based applications is to efficiently isolate and expand large numbers of HKCs with high potential in vitro7,8. Although various research groups have developed methods to produce cultures of stem-like HKCs, these methods are sometimes time-consuming and complicated to perform and have other limitations, such as low cell yields and being limited by the type of skin specimen used9. For instance, the traditional method to isolate HKCs from skin tissues involves a two-step enzymatic digestion with a separation of the epidermis from the dermis6. That method usually works well for neonatal tissues, but it becomes very difficult when used to isolate cells from adult tissues.
Y-27632, an inhibitor of Rho-associated protein kinase (ROCK), has been reported to significantly enhance the efficiency of epidermal stem cell isolation and colony growth10,11,12. In a previous study, we discovered that Y-27632 facilitates the clonal growth of epidermal cells but reduces the yield of dermal cells by differentially controlling the expression of adhesion molecules13. We also established a new conditioned inoculation medium, called G-medium, which supports the growth and yield of primary epidermal cells. By combining G-medium with Y-27632, this novel method can spontaneously separate epidermal and dermal cells after enzyme digestion, thus removing the step of epidermis-dermis separation13,14. Based on previous reports, we now describe the detailed procedure of this new method to isolate HKCs from adult skin tissue.

<table border="0" cellpadding="0" cellspacing="0" style="width:1344px;" width="1342">
	<tbody>
		<tr height="23">
			<td height="23" style="height:23px;width:263px;">Countess automated cell counter</td>
			<td style="width:291px;">Invitrogen Inc.&#160;</td>
			<td style="width:264px;">C10227</td>
			<td style="width:527px;">Automatic cell counting&#160;</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">CO2 Incubator</td>
			<td>Thermo Scientific</td>
			<td>51026333</td>
			<td>For cell incubating</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Sorvall ST 16R Centrifuge</td>
			<td>Thermo Scientific</td>
			<td>75004380</td>
			<td>Cell centrifuge</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Constant Temperature Shaker</td>
			<td>Shanghai Boxun</td>
			<td>150036</td>
			<td>For water bath</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Electronic Scale</td>
			<td>Harbin Zhonghui</td>
			<td>1171193</td>
			<td>For tissue weighing</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Cell Culture Dish</td>
			<td>Eppendorf</td>
			<td>30702115</td>
			<td>For cell culture</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">50ml Centrifuge Tube</td>
			<td>KIRGEN</td>
			<td>171003</td>
			<td>For cell centrifuge</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Cell Strainer</td>
			<td>Corning incorporated</td>
			<td>431792</td>
			<td>Cell filtration</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Phosphate buffered solution</td>
			<td>Solarbio Life Science&#160;</td>
			<td>P1020-500</td>
			<td>Washing solution</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">DMEM</td>
			<td>Thermo Scientific</td>
			<td>C11995500</td>
			<td>Component of neutralization medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Defined K-SFM</td>
			<td>Life Technologies</td>
			<td>10785-012</td>
			<td>Epidermal cells culture medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Penicillin Streptomycin</td>
			<td>Thermo Scientific</td>
			<td>15140-122</td>
			<td>Antibiotics</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Fetal Bovine Serum</td>
			<td>Biological Industries</td>
			<td>04-001-1AC5</td>
			<td>Component of neutralization medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">0.05% Trypsin</td>
			<td>Life Technologies</td>
			<td>25300-062</td>
			<td>For HKC dissociation</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">0.25% Trypsin&#160;</td>
			<td>Beijing Solarbio Science &#38; Technology</td>
			<td>T1350-100</td>
			<td>For HKC dissociation</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Coating Matrix Kit</td>
			<td>Life Technologies</td>
			<td>R-011-K</td>
			<td>For coating matrix</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Dispase</td>
			<td>Gibco</td>
			<td>17105-041</td>
			<td>For HKC isolation</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Collagenase Type I</td>
			<td>Life Technologies</td>
			<td>17100-017</td>
			<td>For HKC isolation</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Deoxyribonuclease I</td>
			<td>Sigma</td>
			<td>9003-98-9</td>
			<td>For HKC isolation</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">F12 Nutrient Mix, Hams</td>
			<td>Life Technologies</td>
			<td>31765035</td>
			<td>Component of G-medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">B27 Supplement</td>
			<td>Life Technologies</td>
			<td>17504044</td>
			<td>Growth factor in G-medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">FGF-2 Millipore</td>
			<td>Merck Biosciences</td>
			<td>341595</td>
			<td>Growth factor in G-medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Y-27632</td>
			<td>Sigma-Aldrich</td>
			<td>Y0503</td>
			<td>ROCK inhibitor</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Fungizone</td>
			<td>Gibco</td>
			<td>15290026</td>
			<td>Preparation for G-medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">EGF Recombinant Human Protein</td>
			<td>Gibco</td>
			<td>PHG0311</td>
			<td>Growth factor in G-medium</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Cell Counting Kit-8</td>
			<td>Thermo Scientific</td>
			<td>NC9864731</td>
			<td>cell proliferation and cytotoxicity assays</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Mouse Anti-Human Cytokeratin5</td>
			<td>Hewlett-Packard Development Company</td>
			<td>MA-20142</td>
			<td>For immunofluorescence staining to check differentiation marker of HKCs</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Rabbit Anti-Human Loricrin</td>
			<td>Covance</td>
			<td>PRB-145p</td>
			<td>For immunofluorescence staining to check differentiation marker of HKCs</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Mouse anti-human Vimentin</td>
			<td>Cell Signaling Technology</td>
			<td>3390</td>
			<td>For immunofluorescence staining of dermal fibroblasts</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;">Integrin &#945;6(GOH3)</td>
			<td>Santa Cruz&#160;</td>
			<td>SC-19622</td>
			<td>flow cytometry analysis of HKCs</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:263px;">Rat IgG2a FITC</td>
			<td>Santa Cruz&#160;</td>
			<td>SC-2831</td>
			<td>negative control antibody of &#945;6-integrin&#160; in flow cytometry analysis&#160;</td>
		</tr>
	</tbody>
</table>

a simplified and efficient method to isolate primary human keratinocytes from adult skin tissue

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical applications. The conventional isolation method of human keratinocytes involves a two-step sequential enzymatic digestion procedure, which has been proven to be inefficient in generating primary cells from adult tissues due to the low cell recovery rate and reduced cell viability. We recently reported an advanced method to isolate human primary epidermal progenitor cells from skin tissues that utilizes the Rho kinase inhibitor Y-27632 in the medium. Compared with the traditional protocol, this new method is simpler, easier, and less time-consuming, and increases epithelial stem cell yield and enhances their stem cell characteristics. Moreover, the new methodology does not require the separation of the epidermis from the dermis, and, therefore, is suitable for isolating cells from different types of adult tissues. This new isolation method overcomes the major shortcomings of conventional methods and is more suitable for producing large numbers of epidermal cells with high potency both for laboratory and for clinical applications. Here, we describe the new method in detail.

Schematic diagrams of the new method (Figure 1A) and the conventional method (Figure 1B) are presented in Figure 1. The conventional method is a two-step digestion, which requires a 2-day procedure. By contrast, the new method is a one-step digestion, which takes around 3 hours to perform. Importantly, the one-step new method can obtain two populations (epidermal and dermal cells) at the same time, w...

Watch this Scientific Journal Video about A Simplified and Efficient Method to Isolate Primary Human Keratinocytes from Adult Skin Tissue at JoVE.com

A Simplified and Efficient Method to Isolate Primary Human Keratinocytes from Adult Skin Tissue

Here we present a protocol to efficiently isolate primary human keratinocytes from adult skin tissues. This method simplifies the conventional procedure by using the ROCK Inhibitor Y-27632 in the inoculation medium to spontaneously separate epidermal cells from dermal cells.

Primary human keratinocytes isolated from fresh skin tissues and their expansion in vitro have been widely used for laboratory research and for clinical ...

The general goal of this video is to introduce a new simple method to isolate and culture primary human epidermal cells from an adult skin tissue. This advanced method is more suitable for producing a large number of high-potential epidermal cells for both laboratory and clinical applications. Wash the tissue with PBS before weighing.Weigh the skin tissue by an electronic scale. Rinse the skin tissue with 70%ethanol for 30 seconds. Incubate the tissue in PBS with antibiotics twice for five minutes each time.Transfer the tissue to another sterile dish and homogenize thoroughly by using scalpel blades. Add 200 microliters of PBS every five minutes to keep the tissue wet. Transfer the homogenized tissue into a 50 milliliter tube.Add 10 milliliters of enzyme mixture for every one gram of skin tissue. Mix the enzymes thoroughly with the homogenized tissues. Incubate the mixture in a 37 degree Celsius water bath with shaking.After that, add 1/5 the volume of 0.25%trypsin. Continue the incubation for 30 minutes in a 37 degree Celsius water bath. Add Dnase I solution to the mixture at a one to 100 ratio.Then incubate for another five minutes. Stop the digestion process by adding the same volume of neutralization medium. Pipette the solution up and down for about 20 times.Filter the dissociated cells through a 100 micrometer cell strainer to remove tissue debris. Centrifuge at 200 g for five minutes. Observe the pellet at the bottom of the tube.Remove the supernatants and wash the cell pellet with 10 milliliters of neutralization medium. Then centrifuge at 200 g for five minutes. Resuspend the cell pellet in the inoculation medium with 10 micromolar ROCK inhibitor.Plate two times 10 to the sixth cells in a 100 millimeter culture dish. After three days, replace the inoculation medium with serum-free keratinocyte medium. Change the medium every two days.When the cells have reached about 80%of the density, passage the cells. Wash the cells with PBS. If necessary, trypsinize for two minutes and wash the cells with PBS to remove contaminated dermal cells.Add the same volume of neutralization medium. Centrifuge at 200 g for five minutes. Finally, remove the supernatants and resuspend the cell pellet.The isolated keratinocytes from human skin tissues were incubated separately by two methods. The conventional method is a two-step digestion which involves a two-day procedure. By contrast, the new method is a one-step digestion which takes around three hours to perform.On day three, we can easily find many cell clusters cultured by the new method while this phenomenon does not occur when using the conventional method. On the fifth day, it was observed that the new method produced a larger amount of primary cells. To test the differentiation status of cultured keratinocytes, we analyzed the basal cell marker K5 and terminal differentiation marker Loricrin.We found that 90%of the total cells were K5 positive, but less than 10%of the cells expressed Loricrin at passage three, indicating that they are undifferentiated keratinocytes. We checked the expression of vimentin which is expressed in the dermal fibroblast to examine the contamination of the dermal cells during isolation. We found that around 3%of the dermal cells appeared in the initial passage, but only around 0.02%of the dermal cells were detected at passage three, indicating a high purity of the epidermal cells after passage.

a-simplified-efficient-method-to-isolate-primary-human-keratinocytes

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 ...

Transfection, Selection, and Colony-picking of Human Induced Pluripotent Stem Cells TALEN-targeted with a GFP Gene into the AAVS1 Safe Harbor

Targeted transgene addition can provide persistent gene expression while circumventing the gene silencing and insertional mutagenesis caused by viral vector mediated random integration. This protocol describes a universal and efficient transgene targeted addition platform in human iPSCs based on utilization of validated open-source TALENs and a gene-trap-like donor to deliver transgenes into a safe harbor locus. Importantly, effective gene editing is rate-limited by the delivery efficiency of gene editing vectors. Therefore, this protocol first focuses on preparation of iPSCs for transfection to achieve high nuclear delivery efficiency. When iPSCs are dissociated into single cells using a gentle-cell dissociation reagent and transfected using an optimized program, >50% cells can be induced to take up the large gene editing vectors. Because the AAVS1 locus is located in the intron of an active gene (PPP1R12C), a splicing acceptor (SA)-linked puromycin resistant gene (PAC) was used to select targeted iPSCs while excluding random integration-only and untransfected cells. This strategy greatly increases the chance of obtaining targeted clones, and can be used in other active gene targeting experiments as well. Two weeks after puromycin selection at the dose adjusted for the specific iPSC line, clones are ready to be picked by manual dissection of large, isolated colonies into smaller pieces that are transferred to fresh medium in a smaller well for further expansion and genetic and functional screening. One can follow this protocol to readily obtain multiple GFP reporter iPSC lines that are useful for in vivo and in vitro imaging and cell isolation.

TALEN-mediated gene editing at the safe harbor AAVS1 locus enables high-efficiency transgene addition in human iPSCs. This protocol describes the procedures for preparing iPSCs for TALEN and donor vector delivery, transfecting iPSCs, and selecting and isolating iPSC clones to achieve targeted integration of a GFP gene to generate reporter lines.

Targeted transgene addition can provide persistent gene expression while circumventing the gene silencing and insertional mutagenesis caused by viral ...

A Quick and Efficient Method for the Purification of Endoderm Cells Generated from Human Embryonic Stem Cells

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell replacement therapies. Terminally differentiated cell types could be used for the treatment of various degenerative diseases. In vitro differentiation of these cells towards tissues of the lung, liver and pancreas requires as a first step the generation of definitive endodermal cells. This step is rate-limiting for further differentiation towards terminally matured cell types such as insulin-producing beta cells, hepatocytes or other endoderm-derived cell types. Cells that are committed towards the endoderm lineage highly express a multitude of transcription factors such as FOXA2, SOX17, HNF1B, members of the GATA family, and the surface receptor CXCR4. However, differentiation protocols are rarely 100% efficient. Here, we describe a method for the purification of a CXCR4+ cell population after differentiation into the DE by using magnetic microbeads. This purification additionally removes cells of unwanted lineages. The gentle purification method is quick and reliable and might be used to improve downstream applications and differentiations.

Here, we describe a method for the purification of differentiated human embryonic stem cells that are committed towards the definitive endoderm for the improvement of downstream applications and further differentiations.

The differentiation capabilities of pluripotent stem cells such as embryonic stem cells (ESCs) allow a potential therapeutic application for cell ...

Epigenetic Conversion as a Safe and Simple Method to Obtain Insulin-secreting Cells from Adult Skin Fibroblasts

Regenerative medicine requires new, fully functional cells that are delivered to patients in order to repair degenerated or damaged tissues. When such cells are not readily available, they can be obtained using different approaches that include, among the many, reprogramming and trans-differentiation, with advantages and limitations that are specific of the different techniques. Here a new strategy for the conversion of an adult mature fibroblast into an insulin-secreting cell, arbitrarily designated as epigenetic converted cells (EpiCC), is described. The method has been developed, based on the increasing understanding of the mechanisms controlling epigenetic regulation of cell fate and differentiation. In particular, the first step uses an epigenetic modifier, namely 5-aza-cytidine, to drive adult cells into a "highly permissive" state. It then takes advantage of this brief and reversible window of epigenetic plasticity, to re-address cells toward a different lineage. The approach is designated "epigenetic cell conversion". It is a simple and robust way to obtain an efficient, controlled and stable cellular inter-lineage switch. Since the protocol does not involve the use of any gene transfection, it is free of viral vectors and does not involve a stable pluripotent state, it is highly promising for translational medicine applications.

Here, a new method that allows the conversion of adult skin fibroblasts into insulin-secreting cells is presented. This technique is based on epigenetic conversion, does not involve the use of retroviral vectors nor the acquisition of a stable pluripotent state. It is therefore highly promising for translational medicine applications.

Regenerative medicine requires new, fully functional cells that are delivered to patients in order to repair degenerated or damaged tissues. When such ...

Isolating Hair Follicle Stem Cells and Epidermal Keratinocytes from Dorsal Mouse Skin

The hair follicle (HF) is an ideal system for studying the biology and regulation of adult stem cells (SCs). This dynamic mini organ is replenished by distinct pools of SCs, which are located in the permanent portion of the HF, a region known as the bulge. These multipotent bulge SCs were initially identified as slow cycling label retaining cells; however, their isolation has been made feasible after identification of specific cell markers, such as CD34 and keratin 15 (K15). Here, we describe a robust method for isolating bulge SCs and epidermal keratinocytes from mouse HFs utilizing fluorescence activated cell-sorting (FACS) technology. Isolated hair follicle SCs (HFSCs) can be utilized in various in vivo grafting models and are a valuable in vitro model for studying the mechanisms that govern multipotency, quiescence and activation.

An ideal model for studying adult stem cell biology is the mouse hair follicle. Here we present a protocol for isolating different populations of hair follicles stem cells and epidermal keratinocytes, employing enzymatic digestion of mouse dorsal skin followed by FACS analysis.

The hair follicle (HF) is an ideal system for studying the biology and regulation of adult stem cells (SCs). This dynamic mini organ is replenished by ...

An Efficient Method to Obtain Dedifferentiated Fat Cells

Tissue engineering and cell therapy hold great promise clinically. In this regard, multipotent cells, such as mesenchymal stem cells (MSCs), may be used therapeutically, in the near future, to restore function to damaged organs. Nevertheless, several technical issues, including the highly invasive procedure of isolating MSCs and the inefficiency surrounding their amplification, currently hamper the potential clinical use of these therapeutic modalities. Herein, we introduce a highly efficient method for the generation of dedifferentiated fat cells (DFAT), MSC-like cells. Interestingly, DFAT cells can be differentiated into several cell types including adipogenic, osteogenic, and chondrogenic cells. Although other groups have previously presented various methods for generating DFAT cells from mature adipose tissue, our method allows us to produce DFAT cells more efficiently. In this regard, we demonstrate that DFAT culture medium (DCM), supplemented with 20% FBS, is more effective in generating DFAT cells than DMEM, supplemented with 20% FBS. Additionally, the DFAT cells produced by our cell culture method can be redifferentiated into several tissue types. As such, a very interesting and useful model for the study of tissue dedifferentiation is presented.

We have modified the conditions for DFAT cell generation and provide herein information regarding the use of an improved growth medium for the production of these cells.

Tissue engineering and cell therapy hold great promise clinically. In this regard, multipotent cells, such as mesenchymal stem cells (MSCs), may be used ...

Isolation and Expansion of Mesenchymal Stem/Stromal Cells Derived from Human Placenta Tissue

Mesenchymal stem/stromal cells (MSC) are promising candidates for use in cell-based therapies. In most cases, therapeutic response appears to be cell-dose dependent. Human term placenta is rich in MSC and is a physically large tissue that is generally discarded following birth. Placenta is an ideal starting material for the large-scale manufacture of multiple cell doses of allogeneic MSC. The placenta is a fetomaternal organ from which either fetal or maternal tissue can be isolated. This article describes the placental anatomy and procedure to dissect apart the decidua (maternal), chorionic villi (fetal), and chorionic plate (fetal) tissue. The protocol then outlines how to isolate MSC from each dissected tissue region, and provides representative analysis of expanded MSC derived from the respective tissue types. These methods are intended for pre-clinical MSC isolation, but have also been adapted for clinical manufacture of placental MSC for human therapeutic use.

Herein we describe methods for the dissection of fetal and maternal tissues from human term placenta, followed by isolation and expansion of mesenchymal stem/stromal cells (MSC) from these tissues.

Mesenchymal stem/stromal cells (MSC) are promising candidates for use in cell-based therapies. In most cases, therapeutic response appears to be cell-dose ...

Generation and Culturing of Primary Human Keratinocytes from Adult Skin

The main function of keratinocytes is to provide the structural integrity of the epidermis, thereby maintaining a mechanical barrier to the outside world. In addition, keratinocytes play an essential role in the initiation, maintenance, and regulation of epidermal immune responses by being part of the innate immune system responding to antigenic stimuli in a fast, nonspecific manner. Here, we describe a protocol for isolation of primary human keratinocytes from adult skin, and demonstrate that these cells respond to calcium-induced terminal differentiation, as measured by an increased expression of the differentiation marker involucrin. In addition, we show that the isolated keratinocytes are responsive to IL-1&#946;-induced activation of intracellular signaling pathways as measured by the activation of the p38 MAPK pathway. Taken together, we describe a method for isolation and culturing of primary human keratinocytes from adult skin. Because the keratinocytes are the predominant cell type in the epidermis, this method is useful to study molecular mechanisms in cutaneous biology in vitro.

The human skin acts as a first line of defense against the external environment. We present a method for isolating primary human keratinocytes from adult skin. These isolated keratinocytes are useful in numerous experimental setups, and are a highly suitable model for studying molecular mechanisms in cutaneous biology in vitro.

The main function of keratinocytes is to provide the structural integrity of the epidermis, thereby maintaining a mechanical barrier to the outside world. ...

The Isolation and Culture of Primary Epicardial Cells Derived from Human Adult and Fetal Heart Specimens

The epicardium, an epithelial cell layer covering the myocardium, has an essential role during cardiac development, as well as in the repair response of the heart after ischemic injury. When activated, epicardial cells undergo a process known as epithelial to mesenchymal transition (EMT) to provide cells to the regenerating myocardium. Furthermore, the epicardium contributes via secretion of essential paracrine factors. To fully appreciate the regenerative potential of the epicardium, a human cell model is required. Here we outline a novel cell culture model to derive primary epicardial derived cells (EPDCs) from human adult and fetal cardiac tissue. To isolate EPDCs, the epicardium is dissected from the outside of the heart specimen and processed into a single cell suspension. Next, EPDCs are plated and cultured in EPDC medium containing the ALK 5-kinase inhibitor SB431542 to maintain their epithelial phenotype. EMT is induced by stimulation with TGF&#946;. This method enables, for the first time, the study of the process of human epicardial EMT in a controlled setting, and facilitates gaining more insight in the secretome of EPDCs that may aid heart regeneration. Furthermore, this uniform approach allows for direct comparison of human adult and fetal epicardial behavior.

The epicardium plays a crucial role in the development and repair of the heart by providing cells and growth factors to the myocardial wall. Here, we describe a method to culture human primary epicardial cells that enables the study and comparison of their developmental and adult characteristics.

The epicardium, an epithelial cell layer covering the myocardium, has an essential role during cardiac development, as well as in the repair response of ...

Whole-mount Confocal Microscopy for Adult Ear Skin: A Model System to Study Neuro-vascular Branching Morphogenesis and Immune Cell Distribution

Here, we present a protocol of a whole-mount adult ear skin imaging technique to study comprehensive three-dimensional neuro-vascular branching morphogenesis and patterning, as well as immune cell distribution at a cellular level. The analysis of peripheral nerve and blood vessel anatomical structures in adult tissues provides some insights into the understanding of functional neuro-vascular wiring and neuro-vascular degeneration in pathological conditions such as wound healing. As a highly informative model system, we have focused our studies on adult ear skin, which is readily accessible for dissection. Our simple and reproducible protocol provides an accurate depiction of the cellular components in the entire skin, such as peripheral nerves (sensory axons, sympathetic axons, and Schwann cells), blood vessels (endothelial cells and vascular smooth muscle cells), and inflammatory cells. We believe this protocol will pave the way to investigate morphological abnormalities in peripheral nerves and blood vessels as well as the inflammation in the adult ear skin under different pathological conditions.

Here, we describe a high resolution whole-mount imaging method in the entire adult mouse ear skin, which enables us to visualize branching morphogenesis and patterning of peripheral nerves and blood vessels, as well as immune cell distribution.