Name: generation of genetically modified organotypic skin cultures using devitalized human dermis
Uploaded: 2015-12-14T14:00:00
Description: Watch this Scientific Journal Video about Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis at JoVE.com

This work was supportedby the American Cancer Society Research Scholars Grant(RSG-12-148-01-DDC) and the CIRM Basic Biology Award (RB4-05779).

The human skin protocol was performed in accordance with the guidelines of the University of California, San Diego&#8217;s Research Ethics Committee. Human skin can be obtained from discarded surgical samples or bought from skin banks (skin bank is listed in the Material/Equipment Table). The location where the skin is derived from or age of the donor is not critical to the experiment as long as the basement membrane zone proteins (collagen/laminin) in the dermis are not degraded.
<p class="jove_titl...

<ol>
	<li>Tadeu, A. M., Horsley, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+stem+cells+in+adult+skin.">Epithelial stem cells in adult skin.</a> Current topics in developmental biology. 107, 107-131 (2014).</li><li>Sen, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remembering+one's+identity:+the+epigenetic+basis+of+stem+cell+fate+decisions.">Remembering one's identity: the epigenetic basis of stem cell fate decisions.</a> FASEB J. 25, 2123-2128 (2011).</li><li>Segre, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidermal+barrier+formation+and+recovery+in+skin+disorders.">Epidermal barrier formation and recovery in skin disorders.</a> J Clin Invest. 116, 1150-1158 (2006).</li><li>Eckert, R. L., Sturniolo, M. T., Broome, A. M., Ruse, M., Rorke, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transglutaminase+function+in+epidermis.">Transglutaminase function in epidermis.</a> J Invest Dermatol. 124, 481-492 (2005).</li><li>Lopez-Pajares, V., Yan, K., Zarnegar, B. J., Jameson, K. L., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+pathways+in+disorders+of+epidermal+differentiation.">Genetic pathways in disorders of epidermal differentiation.</a> Trends Genet. 29, 31-40 (2013).</li><li>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+differentiation:+the+bare+essentials.">Epidermal differentiation: the bare essentials.</a> J Cell Biol. 111, 2807-2814 (1990).</li><li>Green, H., Kehinde, O., Thomas, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+cultured+human+epidermal+cells+into+multiple+epithelia+suitable+for+grafting.">Growth of cultured human epidermal cells into multiple epithelia suitable for grafting.</a> Proc Natl Acad Sci U S A. 76, 5665-5668 (1979).</li><li>Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modelling+cancer+in+human+skin+tissue.">Modelling cancer in human skin tissue.</a> Nat Rev Cancer. 6, 270-280 (2006).</li><li>Parenteau, N. L., Bilbo, P., Nolte, C. J., Mason, V. S., Rosenberg, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+organotypic+culture+of+human+skin+keratinocytes+and+fibroblasts+to+achieve+form+and+function.">The organotypic culture of human skin keratinocytes and fibroblasts to achieve form and function.</a> Cytotechnology. 9, 163-171 (1992).</li><li>Oh, J. W., Hsi, T. C., Guerrero-Juarez, C. F., Ramos, R., Plikus, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organotypic+skin+culture.">Organotypic skin culture.</a> J Invest Dermatol. 133, e14 (2013).</li><li>Sen, G. 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=ZNF750+Is+a+p63+Target+Gene+that+Induces+KLF4+to+Drive+Terminal+Epidermal+Differentiation.">ZNF750 Is a p63 Target Gene that Induces KLF4 to Drive Terminal Epidermal Differentiation.</a> Dev Cell. 22, 669-677 (2012).</li><li>Sen, G. L., Webster, D. E., Barragan, D. I., Chang, H. Y., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+differentiation+in+a+self-renewing+mammalian+tissue+by+the+histone+demethylase+JMJD3.">Control of differentiation in a self-renewing mammalian tissue by the histone demethylase JMJD3.</a> Genes Dev. 22, 1865-1870 (2008).</li><li>Mistry, D. S., Chen, Y., Wang, Y., Zhang, K., Sen, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SNAI2+controls+the+undifferentiated+state+of+human+epidermal+progenitor+cells.">SNAI2 controls the undifferentiated state of human epidermal progenitor cells.</a> Stem Cells. 32, 3209-3218 (2014).</li><li>Truong, A. B., Kretz, M., Ridky, T. W., Kimmel, R., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=p63+regulates+proliferation+and+differentiation+of+developmentally+mature+keratinocytes.">p63 regulates proliferation and differentiation of developmentally mature keratinocytes.</a> Genes Dev. 20, 3185-3197 (2006).</li><li>Kretz, 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=Control+of+somatic+tissue+differentiation+by+the+long+non-coding+RNA+TINCR.">Control of somatic tissue differentiation by the long non-coding RNA TINCR.</a> Nature. 493, 231-235 (2013).</li><li>Ridky, T. W., Chow, J. M., Wong, D. J., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invasive+three-dimensional+organotypic+neoplasia+from+multiple+normal+human+epithelia.">Invasive three-dimensional organotypic neoplasia from multiple normal human epithelia.</a> Nat Med. 16, 1450-1455 (2010).</li><li>Mistry, D. S., Chen, Y., Sen, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progenitor+function+in+self-renewing+human+epidermis+is+maintained+by+the+exosome.">Progenitor function in self-renewing human epidermis is maintained by the exosome.</a> Cell Stem Cell. 11, 127-135 (2012).</li><li>Kretz, 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=Suppression+of+progenitor+differentiation+requires+the+long+noncoding+RNA+ANCR.">Suppression of progenitor differentiation requires the long noncoding RNA ANCR.</a> Genes Dev. 26, 338-343 (2012).</li><li>Mulder, K. 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=Diverse+epigenetic+strategies+interact+to+control+epidermal+differentiation.">Diverse epigenetic strategies interact to control epidermal differentiation.</a> Nat Cell Biol. 14, 753-763 (2012).</li><li>Boxer, L. D., Barajas, B., Tao, S., Zhang, J., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ZNF750+interacts+with+KLF4+and+RCOR1,+KDM1A,+and+CTBP1/2+chromatin+regulators+to+repress+epidermal+progenitor+genes+and+induce+differentiation+genes.">ZNF750 interacts with KLF4 and RCOR1, KDM1A, and CTBP1/2 chromatin regulators to repress epidermal progenitor genes and induce differentiation genes.</a> Genes Dev. 28, 2013-2026 (2014).</li><li>Jameson, K. 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=IQGAP1+scaffold-kinase+interaction+blockade+selectively+targets+RAS-MAP+kinase-driven+tumors.">IQGAP1 scaffold-kinase interaction blockade selectively targets RAS-MAP kinase-driven tumors.</a> Nat Med. 19, 626-630 (2013).</li><li>Mistry, D. S., Chen, Y., Wang, Y., Sen, G. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptional+profiling+of+SNAI2+regulated+genes+in+primary+human+keratinocytes.">Transcriptional profiling of SNAI2 regulated genes in primary human keratinocytes.</a> Genomics data. 4, 43-46 (2015).</li><li>Mali, P., 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=RNA-guided+human+genome+engineering+via+Cas9.">RNA-guided human genome engineering via Cas9.</a> Science. 339, 823-826 (2013).</li><li>Doebis, 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=Efficient+in+vitro+transduction+of+epithelial+cells+and+keratinocytes+with+improved+adenoviral+gene+transfer+for+the+application+in+skin+tissue+engineering.">Efficient in vitro transduction of epithelial cells and keratinocytes with improved adenoviral gene transfer for the application in skin tissue engineering.</a> Transpl immunol. 9, 323-329 (2002).</li><li>Melo, S. P., 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=Somatic+correction+of+junctional+epidermolysis+bullosa+by+a+highly+recombinogenic+AAV+variant.">Somatic correction of junctional epidermolysis bullosa by a highly recombinogenic AAV variant.</a> Mol Ther. 22, 725-733 (2014).</li><li>Nanba, D., Matsushita, N., Toki, F., Higashiyama, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+expansion+of+human+keratinocyte+stem/progenitor+cells+carrying+a+transgene+with+lentiviral+vector.">Efficient expansion of human keratinocyte stem/progenitor cells carrying a transgene with lentiviral vector.</a> Stem cell res ther. 4, 127 (2013).</li><li>Sen, G. L., Reuter, J. A., Webster, D. E., Zhu, L., Khavari, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNMT1+maintains+progenitor+function+in+self-renewing+somatic+tissue.">DNMT1 maintains progenitor function in self-renewing somatic tissue.</a> Nature. 463, 563-567 (2010).</li><li>Shamir, E. R., Ewald, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+organotypic+culture:+experimental+models+of+mammalian+biology+and+disease.">Three-dimensional organotypic culture: experimental models of mammalian biology and disease.</a> Nat Rev Mol Cell Biol. 15, 647-664 (2014).</li><li>Krejci, N. C., Cuono, C. B., Langdon, R. C., McGuire, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+reconstitution+of+skin:+fibroblasts+facilitate+keratinocyte+growth+and+differentiation+on+acellular+reticular+dermis.">In vitro reconstitution of skin: fibroblasts facilitate keratinocyte growth and differentiation on acellular reticular dermis.</a> J Invest Dermatol. 97, 843-848 (1991).</li><li>Mathes, S. H., Ruffner, H., Graf-Hausner, U. <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+skin+models+in+drug+development.">The use of skin models in drug development.</a> Adv Drug Deliv Rev. 69-70, 81-102 (2014).</li></ol>

Genetic manipulation in human skin organotypic cultures offer many advantages to commonly studied 2D cultured cells as well as mouse models. 2D cultures lack the three dimensional cell-cell and cell-extracellular matrix interactions found in intact tissues and organs. Recent studies have also found tremendous differences between 2D and 3D cultured skin cancer cells with the 3D cultured cells showing much more gene expression similarities to primary human skin tumors16. Human organotypic skin cultures also have...

The human epidermis is a stratified epithelium that connects to the underlying dermis through an extracellular matrix known as the basement membrane zone.The epidermis not only serves as an impermeable barrier to prevent the loss of moisture but also as a first line of defense to protect the body from foreign and toxic substances1. The basal layer, which is the deepest layer of the epidermis, contains the epidermal stem and progenitor cells that give rise to the differentiated progeny that form the rest of the epidermis2. As epidermal progenitor cells differentiate they migrate upwards to form the first layer of differentiated cells known as the spinous layer3. In the spinous layer, cells turn on the expression of keratins 1 and 10, which then provide the strength to withstand physical stress for the differentiated layers of the epidermis. As the spinous layer cells further differentiate, they move upwards in the epidermis to form the granular layer which is characterized by the formation of keratohyalin and lamellar granules as well as structural proteins that are assembled below the plasma membrane. As the cells proceed in the differentiation process, the proteins beneath the plasma membrane are cross linked to each other while the lamellar granules are extruded from the cells to form a lipid rich barrier called the stratum corneum4.
Diseases that involve alterations in epidermal growth and differentiation impact ~20% of the population5. Thus, understanding the mechanisms of this process is of great importance. Since manifestation of many of these diseases is contingent upon cell-cell or cell-matrix contact, organotypic cultures where the human epidermis is reconstituted in a 3D environment have been created6-10. These methods typically involve the use of primary or transformed keratinocytes seeded on extracellular matrix such as devitalized human dermis, Matrigel, or collagen.
To understand gene regulatory mechanisms that are important in epidermal growth and differentiation, keratinocytes can be genetically manipulated through retroviral vectors to knockdown or overexpress genes in 2D culture and then reconstituted in 3D. These methods have been used extensively to characterize genes involved in epidermal stem and progenitor cell self-renewal and differentiation as well as progression to neoplasia11-21. Here, an in-depth protocol on how to alter gene expression in epidermal organotypic cultures through the use of retroviruses is provided.

<table>
	<tbody>
		<tr>
			<td>Human skin</td>
			<td>New York Firefighters Skin Bank</td>
			<td><a href="http://www.cornellsurgery.org/pro/services/burn-surgery/skin-bank.html">http://www.cornellsurgery.org/pro/services/burn-surgery/skin-bank.html</a></td>
		</tr>
		<tr>
			<td>PEN/STREP</td>
			<td>GIBCO</td>
			<td>15140-122</td>
		</tr>
		<tr>
			<td>amphotropic phoenix cell lines</td>
			<td>ATCC</td>
			<td>CRL-3213</td>
		</tr>
		<tr>
			<td>FUGENE 6 transfection reagent</td>
			<td>Promega</td>
			<td>E2691</td>
		</tr>
		<tr>
			<td>Keratinocyte Media (KCSFM)</td>
			<td>Life Technologies</td>
			<td>17005042</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>GIBCO</td>
			<td>11995</td>
		</tr>
		<tr>
			<td>Ham&#39;s F12</td>
			<td>Cambrex</td>
			<td>12-615F</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>GIBCO</td>
			<td>10437-028</td>
		</tr>
		<tr>
			<td>Adenine</td>
			<td>Sigma</td>
			<td>A-9795</td>
		</tr>
		<tr>
			<td>Cholera Toxin</td>
			<td>Sigma</td>
			<td>&#160;C-8052</td>
		</tr>
		<tr>
			<td>Hydrocortisone</td>
			<td>Calbiochem</td>
			<td>3896</td>
		</tr>
		<tr>
			<td>Insulin</td>
			<td>Sigma</td>
			<td>I-1882</td>
		</tr>
		<tr>
			<td>EGF</td>
			<td>Invitrogen</td>
			<td>13247-051</td>
		</tr>
		<tr>
			<td>Transferrin&#160;</td>
			<td>Sigma</td>
			<td>T-0665</td>
		</tr>
		<tr>
			<td>Ciprofloxacin Hydrochloride</td>
			<td>Serologicals</td>
			<td>89-001-1</td>
		</tr>
		<tr>
			<td>cautery</td>
			<td>Bovie Medical Corporation</td>
			<td>AA01</td>
		</tr>
		<tr>
			<td>Matrigel</td>
			<td>Corning</td>
			<td>354234</td>
		</tr>
		<tr>
			<td>Keratin 1 antibody</td>
			<td>Biolegend</td>
			<td>PRB-149P</td>
		</tr>
		<tr>
			<td>square pegs</td>
			<td>Arts and crafts stores</td>
			<td></td>
		</tr>
		<tr>
			<td>human neonatal keratinocytes</td>
			<td>ATCC</td>
			<td>PCS-200-010</td>
		</tr>
		<tr>
			<td>human neonatal keratinocytes</td>
			<td>Cell Applications</td>
			<td>102K-05n</td>
		</tr>
		<tr>
			<td>MSCV retroviral vector</td>
			<td>Clontech</td>
			<td>634401</td>
		</tr>
		<tr>
			<td>LZRS retroviral vector</td>
			<td>Addgene</td>
			<td></td>
		</tr>
		<tr>
			<td>pSuper.Retro.Puro Retroviral vector</td>
			<td>Oligoengine</td>
			<td>VEC-PRT-0002&#160;</td>
		</tr>
		<tr>
			<td>hexadimethrine bromide&#160;</td>
			<td>Sigma</td>
			<td>H9268-5G</td>
		</tr>
	</tbody>
</table>

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 first step in generating organotypic human skin is to remove the epidermis from the dermis. The two week incubation of the skin at 37&#160;&#176;C in 4x pen/strep/PBS should allow the separation of the dermis from the epidermis (Figure 1A). If separating the epidermis and dermis is difficult then place the tissue at 37&#160;&#176;C in 4x pen/strep/PBS for another week and then try peeling again using forceps.
One of the keys to regenerating human epidermis on devitalized d...

Watch this Scientific Journal Video about Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis at JoVE.com

Generation of Genetically Modified Organotypic Skin Cultures Using Devitalized Human Dermis

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 ...

Research

JoVE Journal

Developmental Biology

Organotypic Slice Cultures for Studies of Postnatal Neurogenesis

Here we describe a technique for studying hippocampal postnatal neurogenesis in the rodent brain using the organotypic slice culture technique. This ...

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 ...

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 ...

3D Organotypic Co-culture Model Supporting Medullary Thymic Epithelial Cell Proliferation, Differentiation and Promiscuous Gene Expression

Intra-thymic T cell development requires an intricate three-dimensional meshwork composed of various stromal cells, i.e., non-T cells. Thymocytes traverse ...

Generation of Integration-free Human Induced Pluripotent Stem Cells Using Hair-derived Keratinocytes

Recent advances in reprogramming allow us to turn somatic cells into human induced pluripotent stem cells (hiPSCs). Disease modeling using ...

Generation of Integration-free Induced Pluripotent Stem Cells from Human Peripheral Blood Mononuclear Cells Using Episomal Vectors

Induced Pluripotent Stem Cells (iPSCs) hold great promise for disease modeling and regenerative therapies. We previously reported the use of Episomal ...

Using Primary Neurosphere Cultures to Study Primary Cilia

The primary cilium is fundamentally important for the proliferation of neural stem/progenitor cells and for neuronal differentiation during embryonic, ...

A Modified Trier Social Stress Test for Vulnerable Mexican American Adolescents

The Trier Social Stress Test (TSST) is a well validated and widely used social stressor that has been shown to induce a 2-4 fold increase in cortisol, the ...

Generation of Genetically Modified Mice through the Microinjection of Oocytes

The use of genetically modified mice has significantly contributed to studies on both physiological and pathological in vivo processes. The pronuclear ...

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. ...