We thank Laura Clarke for her invaluable assistance. This work is supported by NCE: Stem Cell Network, CIHR and NIH.

1. Prepare the Dissecting Solutions and Enzyme Solutions
<ol>
	<li>Make the Artificial Cerebral Spinal Fluid (ACSF) and the Serum-free Media ahead of time and refrigerate.</li>
	<li>Weigh out the Kynurenic Acid (0.2 mg/mL)and dissolve in 10 mL of hilo ACSF in a 37&deg; C waterbath ahead of time since it does not readily dissolve.</li>
	<li>Weigh out the Trypsin (1.33 mg/mL) and Hyaluronidase (0.67 mg/mL) and place in one 15 mL tube and keep it at -20&deg;C until needed. Add the Kynurenic Acid solution to this tube and filter using a 22 &mu;m syringe filter just prior to use.</li>
	<li>Weigh out Trypsin Inhibitor (Ovamucoid: 1 mg/mL) and dissolve in warm Serum-free Media and filter using 22&mu;m syringe filter.</li>
	<li>Make the plating media: Serum-free Media containing FGF2 (10 ng/mL) and Heparin (2 &mu;g/mL).</li>
</ol>
2. Isolating Retinal Stem Cells from the Mouse Eye
<ol>
	<li>Isolation of the retinal stem cells is performed in a specific sterile room dedicated to primary culture experiments. Prior to starting this procedure, set up the dissecting microscope and cold-light source, and then lay out the sterile dissecting instruments. Each hood has a hot bead sterilizer for sterilizing the instruments between steps.</li>
	<li>We will isolate retinal stem cells from eyes that have been placed immediately in a sterile Petri dish containing Artificial Cerebral Spinal Fluid (ACSF) after their removal from mice sacrificed according to approved animal ethics protocols.</li>
	<li>Under the dissecting microscope, clean the eye with forceps: get rid of the hair and the connective tissue that is attached to the cornea/scleral border. Then transfer the eye to a new dish with ACSF.</li>
	<li>While gently holding the eye stationary with serrated forceps, use angled micro-dissecting scissors to remove the ocular muscles. Remove the optic nerve as well if it is still attached to the eye. Try not to squish the eye during this process. Transfer eyes to a new dish with ACSF.</li>
	<li>Next use curved micro-dissecting scissors to cut the eye in half: begin at the optic nerve and cut through the middle of the cornea, meeting back at the optic nerve where the cut was initiated. It is ideal if the two pieces of eye are roughly equivalent in size because this will make the next step easier.</li>
	<li>Holding the corneas using two forceps, gently peel the two eye halves apart. Remove and discard the lens, viscera, and the neural retinal from the eye shells. Transfer the shells to a new dish with ACSF.</li>
	<li>Now we are ready to isolate the ciliary epithelium. To begin, orient the eye shell so that the cornea is on your right and the Retinal Pigmented Epithelium (RPE) is on the left. Gently pin the eye shell down with straight forceps on the RPE side.</li>
	<li>Next, use a scalpel to cut the cornea and iris away from the ciliary epithelium of the eye by gently pushing down on the scalpel rather than using sawing motions.</li>
	<li>After that, cut the ciliary epithelium away from the RPE. Use non-serrated forceps to transfer the strip of ciliary epithelium to a new 35-mm dish containing ACSF.</li>
	<li>In the same way, isolate the ciliary epithelium from the other eye shell. </li>
	<li>Once both ciliary epithelial strips have been collected, transfer the strips into a 35-mm dish containing 2 mL of Dispase. Place the dish with the strips in a 37&deg; C incubator for 10 minutes.</li>
	<li>After 10 minutes, transfer the strips from the Dispase into a dish containing 2 mL of filtered Trypsin, Hyaluronidase, and Kynurenic Acid. Place the dish at 37 &deg;C for 10 minutes.</li>
	<li>Now return to the dissecting microscope. While holding the sclera down with straight forceps, use the bottom of the curved non-serrated forceps to gently scrape the ciliary epithelium away from the sclera.</li>
	<li>Remove the sclera from the dish. All that should be left in the dish now are the cells of interest and the enzyme solution.</li>
	<li>Using a fire-polished cotton-plugged pipette, transfer this solution into a 14-ml tube. Triturate this solution 30 times to break apart the epithelial cells by gently forcing the solution in and out of the pipette.</li>
	<li>Centrifuge the tube for 5 minutes at 1500 RPM. When the centrifugation is done, remove the tube from the centrifuge carefully since the cells are prone to coming off the bottom of the tube at this stage.</li>
	<li>Gently aspirate the majority of the supernatant using a fire-polished pipette, and then add 1 mL of Trypsin inhibitor in Serum-free Media to the cells. Use a small borehole cotton-plugged pipette to triturate the sample approximately 50 times until it is a single-cell suspension.</li>
	<li>Centrifuge the tube again for 5 minutes at 1500 RPM.</li>
	<li>Remove the supernatant and replace it with 1 mL of your plating medium. Triturate gently using a fire-polished glass pipette to resuspend the cells. </li>
	<li>After counting the cells, plate them at the desired density in a 24-well plate. We usually plate 10 cells/&mu;L by filling each well first with medium and then adding the cell suspension to get a final volume of 500 &mu;L of media.</li>
	<li>Place the plate in a 37&deg; C CO2 incubator where it will not be moved until you count the spheres that arise after 7 days.</li>
</ol>
3. Results of Isolating Retinal Stem Cells
<ol>
	<li>When this procedure is performed successfully, the dissected ciliary epithelial cells should look like this after being dissociated and plated at low density (Figure 1).</li>
	<li>After 7 days in culture, the retinal stem cell spheres that arise are counted. A sphere should be over 75 &mu;m in diameter and free-floating to be counted as a stem cell derived sphere. (Figure 2). However, some cells will have limited proliferation and form spheroids that do not meet size criterion and will not be counted as stem cell derived spheres; an example of such a spheroid is shown here (Figure 2).</li>
</ol>
4. Representative Results
<img src="/files/ftp_upload/2209/2209fig1.jpg" alt="Figure 1" /> Figure 1.
<img src="/files/ftp_upload/2209/2209fig2.jpg" alt="Figure 2" /> Figure 2.

<ol>
	<li>Tropepe, V., Coles, B. L., Chiasson, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+stem+cells+in+the+adult+mammalian+eye.">Retinal stem cells in the adult mammalian eye.</a> Science. 287, 2032-2036 (2000).</li><li>Ahmad, I., Tang, L., Pham, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+neural+progenitors+in+the+adult+mammalian+eye.">Identification of neural progenitors in the adult mammalian eye.</a> Biochem Biophys Res Commun. 270, 517-521 (2000).</li><li>Coles, B. L., Angenieux, B., Inoue, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Facile+isolation+and+the+characterization+of+human+retinal+stem+cells.">Facile isolation and the characterization of human retinal stem cells.</a> Proc Natl Acad Sci U S A. 101, 15772-15777 (2004).</li><li>Cicero, S. A., Johnson, D., Reyntjens, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cells+previously+identified+as+retinal+stem+cells+are+pigmented+ciliary+epithelial+cells.">Cells previously identified as retinal stem cells are pigmented ciliary epithelial cells.</a> Proc Natl Acad Sci U S A. 106, 6685-6690 (2009).</li><li>Lamba, D., Karl, M., Reh, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+regeneration+and+cell+replacement:+a+view+from+the+eye.">Neural regeneration and cell replacement: a view from the eye.</a> Cell Stem Cell. 2 (6), 538-549 (2008).</li><li>Coles, B. L., Horsford, D. J., McInnes, R. R., van der Kooy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loss+of+retinal+progenitor+cells+leads+to+an+increase+in+the+retinal+stem+cell+population+in+vivo.">Loss of retinal progenitor cells leads to an increase in the retinal stem cell population in vivo.</a> Eur J Neurosci. 23, 75-82 (2006).</li><li>Ang&#233;nieux, B., Schorderet, F. D., Arsenijevic, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidermal+growth+factor+is+a+neuronal+differentiation+factor+for+retinal+stem+cells+in+vitro.">Epidermal growth factor is a neuronal differentiation factor for retinal stem cells in vitro.</a> Stem Cells. 24 (3), 696-706 (2006).</li><li>Xu, S., Sunderland, M. E., Coles, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+proliferation+and+expansion+of+retinal+stem+cells+require+functional+Pax6.">The proliferation and expansion of retinal stem cells require functional Pax6.</a> Dev Biol. 304, 713-721 (2007).</li><li>Canola, K., Ang&#233;nieux, B., Tekaya, M., Quiambao, A., Naash, M. I., Munier, F. L., Schorderet, D. F., Arsenijevic, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+stem+cells+transplanted+into+models+of+late+stages+of+retinitis+pigmentosa+preferentially+adopt+a+glial+or+a+retinal+ganglion+cell+fate.">Retinal stem cells transplanted into models of late stages of retinitis pigmentosa preferentially adopt a glial or a retinal ganglion cell fate.</a> Invest Ophthalmol Vis Sci. 48 (1), 446-4454 (2007).</li><li>Canola, K., Arsenijevic, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+cells+committed+towards+the+photoreceptor+fate+for+retinal+transplantation.">Generation of cells committed towards the photoreceptor fate for retinal transplantation.</a> Neuroreport. 18 (9), 851-855 (2007).</li><li>Djojosubroto, M. W., Arsenijevic, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinal+stem+cells:+promising+candidates+for+retina+transplantation.">Retinal stem cells: promising candidates for retina transplantation.</a> Cell Tissue Res. 331 (1), 347-357 (2008).</li><li>Inoue, T., Coles, B. L., Dorval, K., Bremner, R., Bessho, Y., Kageyama, R., Hino, S., Matsuoka, M., Craft, C. M., McInnes, R. R., Tremblay, F., Prusky, G. T., van der Kooy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maximizing+functional+photoreceptor+differentiation+from+adult+human+retinal+stem+cells.">Maximizing functional photoreceptor differentiation from adult human retinal stem cells.</a> Stem Cells. 28 (3), 489-500 (2010).</li><li>Tropepe, V., Sibilia, M., Ciruna, B. G., Rossant, J., Wagner, E. F., Kooy, D. v. a. n. d. e. r. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+neural+stem+cells+proliferate+in+response+to+EGF+and+FGF+in+the+developing+mouse+telencephalon.+Dev+Biol.">Distinct neural stem cells proliferate in response to EGF and FGF in the developing mouse telencephalon. Dev Biol.</a> , 208-201 (1999).</li><li>Coles-Takabe, B. L., Brain, I., Purpura, K. A., Karpowicz, P., Zandstra, P. W., Morshead, C. M., van der Kooy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Don't+look:+growing+clonal+versus+nonclonal+neural+stem+cell+colonies.">Don't look: growing clonal versus nonclonal neural stem cell colonies.</a> Stem Cells. 26 (11), 2938-2944 (2008).</li></ol>

No conflicts of interest declared.

This protocol describes how to isolate retinal stem cells from the ciliary epithelium of the mouse eye 1-3. The methodology for isolating the strips of ciliary epithelium can vary, however the enzymes and methodology for attaining a single-cell suspension have been optimized in this protocol. It is also important that the strips of ciliary epithelium that have been isolated do not contain large amounts of RPE or cornea since these appear to have a negative impact on the total number of spheres that can be isolated from each eye. In addition, the serum-free media that we make that was originally formulated for brain neurospheres 13, is ideal for growing retinal stem cell spheres. One should also make sure that the cells are not disturbed after they have been plated and placed in the incubator so that the growing spheres do not aggregate together 14.
Once the retinal stem cells have formed clonal spheres, they can be counted to get a prospective number of stem cells per eye. The spheres then can then be dissociated into single cells and passaged to ascertain self-renewal capabilities or differentiated into the different cell types of the neural retina and RPE using different combinations of growth factors and/or proteins.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>Stemi 2000 Microscope</td>
<td>&nbsp;</td>
<td>Zeiss</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Cold Light Source</td>
<td>&nbsp;</td>
<td>Zeiss</td>
<td>KL1500 </td>
<td>dual arm optic light</td>
</tr>
<tr>
<td>Curved Mini Vannas scissors</td>
<td>&nbsp;</td>
<td>FST</td>
<td>15000-10</td>
<td>&nbsp;</td>
<tr>
<td>Angled Vannas scissors</td>
<td>&nbsp;</td>
<td>FST</td>
<td>15005-08</td>
<td>&nbsp;</td>
<tr>
<td>#7 Dumont forceps</td>
<td>&nbsp;</td>
<td>FST</td>
<td>11272-30</td>
<td>non-serrated</td>
</tr>
<tr>
<td>#5 Dumont forceps</td>
<td>&nbsp;</td>
<td>FST</td>
<td>11251-10</td>
<td>straight</td>
</tr>
<tr>
<td>Fine forceps</td>
<td>&nbsp;</td>
<td>FST</td>
<td>11051-10</td>
<td>serrated curved</td>
</tr>
<tr>
<td>#3 Scalpel handle</td>
<td>&nbsp;</td>
<td>Almedic</td>
<td>2586-M36-10</td>
<td>&nbsp;</td>
<tr>
<td>#10 Scalpel blades</td>
<td>&nbsp;</td>
<td>Almedic</td>
<td>2580-M90-10</td>
<td>&nbsp;</td>
<tr>
<td>Hot Bead Sterilizer</td>
<td>&nbsp;</td>
<td>FST</td>
<td>18000-45</td>
<td>&nbsp;</td>
<tr>
<td>Dispase</td>
<td>&nbsp;</td>
<td>VWR/BD </td>
<td>CACB354235</td>
<td>&nbsp;</td>
<tr>
<td>Trypsin</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>T1005</td>
<td>&nbsp;</td>
<tr>
<td>Hyaluronidase</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>H6254</td>
<td>&nbsp;</td>
<tr>
<td>Kynurenic Acid</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>K3375</td>
<td>1000 IU</td>
</tr>
<tr>
<td>Trypsin Inhibitor</td>
<td>&nbsp;</td>
<td>Roche</td>
<td>10109878001</td>
<td>&nbsp;</td>
<tr>
<td>35 mm dishes</td>
<td>&nbsp;</td>
<td>VWR/Nunc</td>
<td>CA354235</td>
<td>&nbsp;</td>
<tr>
<td>24-well plate</td>
<td>&nbsp;</td>
<td>VWR/Nunc</td>
<td>CA73521-004</td>
<td>&nbsp;</td>
<tr>
<td>Cotton-plugged pipettes</td>
<td>&nbsp;</td>
<td>VWR</td>
<td>14672-400</td>
<td>fire-polish</td>
</tr>
<tr>
<td>14 mL Tubes</td>
<td>&nbsp;</td>
<td>Falcon</td>
<td>352057</td>
<td>Polystyrene</td>
</tr>
<tr>
<td>Serum-free Media</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>Ref# 13 for formulation</td>
</tr>
<tr>
<td>FGF2</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>F0291</td>
<td>&nbsp;</td>
<tr>
<td>Heparin</td>
<td>&nbsp;</td>
<td>Sigma</td>
<td>H3149</td>
<td>100 IU</td>
</tr>		</tbody>
		</table>
		</div>

isolation of retinal stem cells from the mouse eye

The adult mouse retinal stem cell (RSC) is a rare quiescent cell found within the ciliary epithelium (CE) of the mammalian eye1,2,3. The CE is made up of non-pigmented inner and pigmented outer cell layers, and the clonal RSC colonies that arise from a single pigmented cell from the CE are made up of both pigmented and non-pigmented cells which can be differentiated to form all the cell types of the neural retina and the RPE. There is some controversy about whether all the cells within the spheres all contain at least some pigment4; however the cells are still capable of forming the different cell types found within the neural retina1-3. In some species, such as amphibians and fish, their eyes are capable of regeneration after injury5, however; the mammalian eye shows no such regenerative properties. We seek to identify the stem cell in vivo and to understand the mechanisms that keep the mammalian retinal stem cells quiescent6-8, even after injury as well as using them as a potential source of cells to help repair physical or genetic models of eye injury through transplantation9-12. Here we describe how to isolate the ciliary epithelial cells from the mouse eye and grow them in culture in order to form the clonal retinal stem cell spheres. Since there are no known markers of the stem cell in vivo, these spheres are the only known way to prospectively identify the stem cell population within the ciliary epithelium of the eye.

Watch this Scientific Journal Video about Isolation of Retinal Stem Cells from the Mouse Eye at JoVE.com

Isolation of Retinal Stem Cells from the Mouse Eye

In this video, we will demonstrate how to isolate retinal stem cells from the ciliary epithelium of the mouse eye and grow them in culture to form clonal retinal spheres. The spheres that are isolated possess the cardinal properties of stem cells: self-renewal and multipotentiality.

The adult mouse retinal stem cell (RSC) is a rare quiescent cell found within the ciliary epithelium (CE) of the mammalian eye1,2,3. The CE is made up of ...

isolation-of-retinal-stem-cells-from-the-mouse-eye

Nanyang Technological University

Research

JoVE Journal

Biology

24.7K Views.  University of Toronto. In this video, we will demonstrate how to isolate retinal stem cells from the ciliary epithelium of the mouse eye and grow them in culture to form clonal retinal spheres. The spheres that are isolated possess the cardinal properties of stem cells: self-renewal and multipotentiality.

Video: Isolation of Retinal Stem Cells from the Mouse Eye

Isolation and Analysis of Hematopoietic Stem Cells from the Placenta

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. All HSCs emerge during embryonic development, after which their pool size is maintained by self-renewing cell divisions. Identifying the anatomical origin of HSCs and the critical developmental events regulating the process of HSC development has been complicated as many anatomical sites participate during fetal hematopoiesis. Recently, we identified the placenta as a major hematopoietic organ where HSCs are generated and expanded in unique microenvironmental niches (Gekas, et al 2005, Rhodes, et al 2008). Consequently, the placenta is an important source of HSCs during their emergence and initial expansion.
In this article, we show dissection techniques for the isolation of murine placenta from E10.5 and E12.5 embryos, corresponding to the developmental stages of initiation of HSCs and the peak in the size of the HSC pool in the placenta, respectively. In addition, we present an optimized protocol for enzymatic and mechanical dissociation of placental tissue into single-cell suspension for use in flow cytometry or functional assays. We have found that use of collagenase for single-cell suspension of placenta gives sufficient yields of HSCs. An important factor affecting HSC yield from the placenta is the degree of mechanical dissociation prior to, and duration of, enzymatic treatment.
We also provide a protocol for the preparation of fixed-frozen placental tissue sections for the visualization of developing HSCs by immunohistochemistry in their precise cellular niches. As hematopoietic specific antigens are not preserved during preparation of paraffin embedded sections, we routinely use fixed frozen sections for localizing placental HSCs and progenitors.

We have identified the placenta as a major hematopoietic organ during development. We found that hematopoietic stem cells (HSCs) are both generated and expanded in the placenta in unique microenvironmental niches. Here, we describe experimental techniques required for isolation and visualization of HSCs in the mouse placenta.

Hematopoietic stem cells (HSCs) have the ability to self-renew and generate all cell types of the blood lineages throughout the lifetime of an individual. ...

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

Isolation of Mouse Salivary Gland Stem Cells

Mature salivary glands of both human and mouse origin comprise a minimum of five cell types, each of which facilitates the production and excretion of saliva into the oral cavity. Serous and mucous acinar cells are the protein and mucous producing factories of the gland respectively, and represent the origin of saliva production. Once synthesised, the various enzymatic and other proteinaceous components of saliva are secreted through a series of ductal cells bearing epithelial-type morphology, until the eventual expulsion of the saliva through one major duct into the cavity of the mouth. The composition of saliva is also modified by the ductal cells during this process.
In the manifestation of diseases such as Sj&ouml;gren's syndrome, and in some clinical situations such as radiotherapy treatment for head and neck cancers, saliva production by the glands is dramatically reduced 1,2. The resulting xerostomia, a subjective feeling of dry mouth, affects not only the ability of the patient to swallow and speak, but also encourages the development of dental caries and can be socially debilitating for the sufferer.
The restoration of saliva production in the above-mentioned clinical conditions therefore represents an unmet clinical need, and as such several studies have demonstrated the regenerative capacity of the salivary glands 3-5. Further to the isolation of stem cell-like populations of cells from various tissues within the mouse and human bodies 6-8, we have shown using the described method that stem cells isolated from mouse salivary glands can be used to rescue saliva production in irradiated salivary glands 9,10. This discovery paves the way for the development of stem cell-based therapies for the treatment of xerostomic conditions in humans, and also for the exploration of the salivary gland as a microenvironment containing cells with multipotent self-renewing capabilities.

An optimized protocol for the isolation of stem cells from the mouse salivary gland is described. The method employs enzymatic and mechanical digestion, and permits isolation of salispheres containing cells with characteristics of stem cells.

Mature salivary glands of both human and mouse origin comprise a minimum of five cell types, each of which facilitates the production and excretion of ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

Isolation and Culture of Dental Epithelial Stem Cells from the Adult Mouse Incisor

Understanding the cellular and molecular mechanisms that underlie tooth regeneration and renewal has become a topic of great interest1-4, and the mouse incisor provides a model for these processes. This remarkable organ grows continuously throughout the animal&#39;s life and generates all the necessary cell types from active pools of adult stem cells housed in the labial (toward the lip) and lingual (toward the tongue) cervical loop (CL) regions. Only the dental stem cells from the labial CL give rise to ameloblasts that generate enamel, the outer covering of teeth, on the labial surface. This asymmetric enamel formation allows abrasion at the incisor tip, and progenitors and stem cells in the proximal incisor ensure that the dental tissues are constantly replenished. The ability to isolate and grow these progenitor or stem cells in vitro allows their expansion and opens doors to numerous experiments not achievable in vivo, such as high throughput testing of potential stem cell regulatory factors. Here, we describe and demonstrate a reliable and consistent method to culture cells from the labial CL of the mouse incisor.

The continuously growing mouse incisor provides a model for studying renewal of dental tissues from dental epithelial stem cells (DESCs). A robust system for consistently and reliably obtaining these cells from the incisor and expanding them in vitro is reported here.

Understanding the cellular and molecular mechanisms that underlie tooth regeneration and renewal has become a topic of great interest1-4, and the mouse ...

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current blastocyst injection protocol. Here we report that a simple rotation of the embryo, and injection through Trans-Inner cell mass (TICM) increased the percentage of chimeric mice from 31% to 50%, with no additional equipment or further specialized training. 26 different inbred clones, and 35 total clones were injected over a period of 9 months. There was no significant difference in either pregnancy rate or recovery rate of embryos between traditional injection techniques and TICM. Therefore, without any major alteration in the injection process and a simple positioning of the blastocyst and injecting through the ICM, releasing the ES cells into the blastocoel cavity can potentially improve the quantity of chimeric production and subsequent germline transmission.

Here we present a protocol to increase chimera production without the use of new equipment. A simple orientation change of the embryo for injection can increase the number of embryos produced, and potentially reduce the timeline to germline transmission.

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current ...

Primary Cell Cultures from the Mouse Retinal Pigment Epithelium

The retinal pigment epithelium (RPE) is a highly polarized multi-functional epithelium that is located between the neural retina and the choroid of the eye. It is a single sheet of pigmented cells that are hexagonally packed and connected by tight junctions. The main functions of the RPE include absorption of light, phagocytosis of the shed photoreceptor outer segments, spatial buffering of ions, transport of nutrients, ions and water as well as active involvement in the visual cycle. With such important and diverse functions, it is critically important to study the biology of RPE cells. A number of RPE cell lines have been established; however, passaged and immortalized cells are known to quickly lose some of the morphological and physiological characteristics of natural RPE cells. Thus, primary cells are more suitable for studying different aspects of RPE cell biology and function. Mouse primary RPE cell culture is very useful to researchers since mouse models are widely used in biological studies, however collecting RPE cells from mouse is also very challenging due to their small size. Here, we present a protocol for establishing primary mouse RPE cell cultures which includes enucleation and dissection of the eyes and isolation of the RPE sheets to yield the cells for culturing. This method enables efficient cell recovery. The RPE cells obtained from two mice&#160;can reach confluency on one 12 mm polyester membrane insert pre-loaded in culture plate after one week of culture and display some of the original properties of bona fide RPE cells such as hexagonal shape and pigmentation after two weeks of culture.

The retinal pigment epithelium (RPE) is a multi-functional epithelium of the eye. Here we present a protocol to establish primary cell cultures derived from the murine RPE.

The retinal pigment epithelium (RPE) is a highly polarized multi-functional epithelium that is located between the neural retina and the choroid of the ...

Isolation, Characterization, and Differentiation of Cardiac Stem Cells from the Adult Mouse Heart

Myocardial infarction (MI) is a leading cause of morbidity and mortality around the world. A major goal of regenerative medicine is to replenish the dead myocardium after MI. Although several strategies have been used to regenerate myocardium, stem cell therapy remains a major approach to replenish the dead myocardium of an MI heart. Accumulating evidence suggests the presence of resident cardiac stem cells (CSCs) in the adult heart and their endocrine and/or paracrine effects on cardiac regeneration. However, CSC isolation and their characterization and differentiation toward myocardial cells, especially cardiomyocytes, remains a technical challenge. In the present study, we provided a simple method for the isolation, characterization, and differentiation of CSCs from the adult mouse heart. Here, we describe a density gradient method for the isolation of CSCs, where the heart is digested by a 0.2% collagenase II solution. To characterize the isolated CSCs, we evaluated the expression of CSCs/cardiac markers Sca-1, NKX2-5, and GATA4, and pluripotency/stemness markers OCT4, SOX2, and Nanog. We also determined the proliferation potential of isolated CSCs by culturing them in a Petri dish and assessing the expression of the proliferation marker Ki-67. For evaluating the differentiation potential of CSCs, we selected seven- to ten-days cultured CSCs. We transferred them to a new plate with a cardiomyocyte differentiation medium. They are incubated in a cell culture incubator for 12 days, while the differentiation medium is changed every three days. The differentiated CSCs express cardiomyocyte-specific markers: actinin and troponin I. Thus, CSCs isolated with this protocol have stemness and cardiac markers, and they have a potential for proliferation and differentiation toward cardiomyocyte lineage.

The overall goal of this article is to standardize the protocol for the isolation, characterization, and differentiation of cardiac stem cells (CSCs) from the adult mouse heart. Here, we describe a density gradient centrifugation method to isolate murine CSCs and elaborated methods for CSC culture, proliferation, and differentiation into cardiomyocytes.

Myocardial infarction (MI) is a leading cause of morbidity and mortality around the world. A major goal of regenerative medicine is to replenish the dead ...

Efficient Dissection and Culture of Primary Mouse Retinal Pigment Epithelial Cells

Eye disorders affect millions of people worldwide, but the limited availability of human tissues hinders their study. Mouse models are powerful tools to understand the pathophysiology of ocular diseases because of their similarities with human anatomy and physiology. Alterations in the retinal pigment epithelium (RPE), including changes in morphology and function, are common features shared by many ocular disorders. However, successful isolation and culture of primary mouse RPE cells is very challenging. This paper is an updated audiovisual version of the protocol previously published by Fernandez-Godino et al. in 2016 to efficiently isolate and culture primary mouse RPE cells. This method is highly reproducible and results in robust cultures of highly polarized and pigmented RPE monolayers that can be maintained for several weeks on Transwells. This model opens new avenues for the study of the molecular and cellular mechanisms underlying eye diseases. Moreover, it provides a platform to test therapeutic approaches that can be used to treat important eye diseases with unmet medical needs, including inherited retinal disorders and macular degenerations.

This protocol, which was originally reported by Fernandez-Godino et al. in 20161, describes a method to efficiently isolate and culture mouse RPE cells, which form a functional and polarized RPE monolayer within one week on Transwell plates. The procedure takes approximately 3 hours.

Eye disorders affect millions of people worldwide, but the limited availability of human tissues hinders their study. Mouse models are powerful tools to ...

Primary Culture of Porcine Retinal Pigment Epithelial Cells

The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells, located between the choroid and neuroretina in the retina. Multiple functions, including phagocytosis, nutrient/metabolite transportation, vitamin A metabolism, etc., are conducted by the RPE on a daily basis. RPE cells are terminally differentiated epithelial cells with little or no regenerative capacity. Loss of RPE cells results in multiple eye diseases leading to visual impairment, such as age-related macular degeneration. Therefore, the establishment of an in vitro culture model of primary RPE cells, which more closely resembles the RPE in vivo than cell lines, is critical for the characteristic and mechanistic studies of RPE cells. Considering the fact that the source of human eyeballs is limited, we create a protocol to culture primary porcine RPE cells. By using this protocol, RPE cells can be easily dissociated from adult porcine eyeballs. Subsequently, these dissociated cells attach to culture dishes/inserts, proliferate to form a confluent monolayer, and quickly re-establish key features of epithelial tissue in vivo within 2 wks. By qRT-PCR, it is demonstrated that primary porcine RPE cells express multiple signature genes at comparable levels with native RPE tissue, while the expressions of most of these genes are lost/highly reduced in human RPE-like cells, ARPE-19. Moreover, the immunofluorescence staining shows the distribution of tight junction, tissue polarity, and cytoskeleton proteins, as well as the presence of RPE65, an isomerase critical for vitamin A metabolism, in cultured primary cells. Altogether, we have developed an easy-to-follow approach to culture primary porcine RPE cells with high purity and native RPE features, which could serve as a good model to understand RPE physiology, study cell toxicities, and facilitate drug screenings.

Here, an easy-to-follow method to culture primary porcine retinal pigment epithelial cells in vitro is presented.

The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells, located between the choroid and neuroretina in the retina. ...