The support and advice of Markus Pajtler and Robert Bohrer were invaluable for the visualization of this protocol.

The authors state that experiments on animals were performed in accordance with the European Communities Council Directive (86/609/EEC), following the Guidelines of the NIH regarding the care and use of animals for experimental procedures and the regulations set forth by the Institutional Animal Care and Use Committee (IACUC) at the University of Duisburg-Essen (Germany).

Part 1: Setting Up (not Shown on Video)
PREPARING MATERIALS AND SOLUTIONS (prior to taking the eggs out of the incubator)
<ul>
<li>Eggs have to be incubated in a humidified incubator for 11 days at 37&deg;C (100&deg;F).</li>
<li>70% ethanol spray, clean plates, precise clean forceps, 4&deg;C (40&deg;F) cold sterile DMEM on ice and 60 mL sterile syringes</li>
<li>50 mL Sterile corning tubes have to be half-filled with 4&deg;C cold DMEM to mix the macerated embryos at a ratio of 1:1 (macerated mass: DMEM). As soon as the eggs are taken out of the incubator dissection of the chick embryos has to be started.</li>
<li>Sterilize dissection tools in the autoclave or on the day of dissection, immerse the tools in 70% ethanol for 20 minutes.</li>
</ul>
Part 2: Dissection of the Chick Embryos (demonstrated on Video)
<ol>
<li>Wet the incubated eggs with a 70% ethanol spray for at least 30 seconds and dry them carefully with clean soft paper towels while not shaking the eggs excessively. 
Note: We recommend not dissecting more than 60 chick embryos simultaneously.</li>
<li>Open the eggs carefully by dashing against a sharp edge and take out the embryo with caution not destroying the yolk sack or the chick embryo itself.</li>
<li>Search for the beginning of the umbilical cord quickly and open the clear wrapping without destroying the yolk sack or any little vessels. Then dissect the umbilical cord with precise clean forceps.</li>
<li>Take the embryo out of the yolk sack. 
Note: Embryos should be decapitated quickly (not shown in the video).</li>
<li>Collect the embryos in minimal essential medium at 4&deg;C.</li>
</ol>
Part 3: Maceration of the Chick Embryos
<ol>
<li>Take the plunger out of a 60 mL sterile syringe.</li>
<li>Transfer approximately 10 embryos into one 60 mL syringe.</li>
<li>Put the plunger carefully back into the syringe in order not to risk losing macerated material.</li>
<li>Macerate by pushing down the plunger.</li>
<li>Collect the macerated mass in the prepared corning tubes half-filled with DMEM at a ratio of 1:1 (macerated mass: DMEM). Using 10 embryos a volume of approximately 25 mL is produced.</li>
<li>Place the mixture on a shaker for 45 min at 4&deg;C.</li>
</ol>
Part 4: Centrifugation of the Chick Embryo - DMEM Suspension
<ol>
<li>Transfer the chick embryo - DMEM suspension into the centrifugation tubes.</li>
<li>Add sterile hyaluronidase at a concentration of 1 mg per 25 mg of embryo.</li>
<li>Tare the centrifugation tubes very precisely. 
Note: This step should be performed with caution as centrifugation is run at very high g-force and damage of material or centrifuge could occur if using imbalanced tubes. With a high accuracy weighing machine accordance regarding the three positions after decimal point for all tubes should be received by adjusting the missing amount with DMEM.</li>
<li>Reduce the temperature of the centrifuge to 4&deg;C. 
Note: Also the centrifugation rotor should be stored in a cooling chamber or fridge over night.</li>
<li>Centrifuge 6 hours at least for 180.000 x g x h. Note: For superior results regarding the separation of the single phases use 266.000 x g x h. If possible, use the vacuum adjustment.</li>
</ol>
Part 5: Filtration of the Chick Embryo Extract
After the centrifugation, three phases can be noticed: The upper dingy liquid phase with fatty fragments, the clear liquid phase in the middle and the pellet at the bottom of the centrifugation tube. Note: Shaking or brisk moving of the centrifuged mixture has to be strictly avoided, as this would destroy the result of the centrifugation step by losing the clear central liquid phase.
Note: All following steps have to be performed under sterile conditions using a laminar air flow bench:
<ol>
<li>Pipette the clear liquid phase into a filter system with pores of 0.45 &mu;m. Then switch on the connected vacuum pump. 
Note: Do not touch the pellet at the bottom. This would lead to a contamination of the extract and a blockage of the filter system.</li>
<li>Transfer the pre-extract into a filter system with pores of 0.22 &mu;m and switch on the connected vacuum pump again. </li>
<li>Aliquot the attained chick embryo extract in sterile 15 mL corning tubes.</li>
<li>Quickly store the aliquots at -80&deg;C (-62&deg;F). Note: The CEE last for up to two years if stored at -80&deg;C.</li>
</ol>

<ol>
	<li>Bronner-Fraser, M., Fraser, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lineage+analysis+reveals+multipotency+of+some+avian+neural+crest+cells.">Cell lineage analysis reveals multipotency of some avian neural crest cells.</a> Nature. 335, 161-164 (1988).</li><li>Stemple, D. L., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+a+stem+cell+for+neurons+and+glia+from+the+mammalian+neural+crest.">Isolation of a stem cell for neurons and glia from the mammalian neural crest.</a> Cell. 71, 973-985 (1992).</li><li>Rao, M. S., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immortalization+and+controlled+in+vitro+differentiation+of+murine+multipotent+neural+crest+stem+cells.">Immortalization and controlled in vitro differentiation of murine multipotent neural crest stem cells.</a> J Neurobiol. 32, 722-746 (1997).</li><li>Paratore, C., Goerich, D. E., Suter, U., Wegner, M., Sommer, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Survival+and+glial+fate+acquisition+of+neural+crest+cells+are+regulated+by+an+interplay+between+the+transcription+factor+Sox10+and+extrinsic+combinatorial+signaling.">Survival and glial fate acquisition of neural crest cells are regulated by an interplay between the transcription factor Sox10 and extrinsic combinatorial signaling.</a> Cell. 128, 3949-3961 (2001).</li><li>Kim, J., Lo, L., Dormand, E., Anderson, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SOX10+maintains+multipotency+and+inhibits+neuronal+differentiation+of+neural+crest+stem+cells.">SOX10 maintains multipotency and inhibits neuronal differentiation of neural crest stem cells.</a> Neuron. 38, 17-31 (2003).</li><li>Anderson, D. J., Groves, A., Lo, L., Ma, Q., Rao, M., Shah, N. M., Sommer, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+lineage+determination+and+the+control+of+neuronal+identity+in+the+neural+crest.">Cell lineage determination and the control of neuronal identity in the neural crest.</a> Review Cold Spring Harb Symp Quant Biol. 62, 493-504 (1997).</li><li>Dorsky, R. I., Moon, R. T., Raible, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+signals+and+cell+fate+specification+in+premigratory+neural+crest.">Environmental signals and cell fate specification in premigratory neural crest.</a> Review Bioessays. 22, 708-716 (2000).</li><li>Sieber-Blum, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+controlling+lineage+specification+in+the+neural+crest.">Factors controlling lineage specification in the neural crest.</a> Int Rev Cytol. 197, 1-33 (2000).</li><li>Dupin, E., Real, C., Ledouarin, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+neural+crest+stem+cells:+control+of+neural+crest+cell+fate+and+plasticity+by+endothelin-3.">The neural crest stem cells: control of neural crest cell fate and plasticity by endothelin-3.</a> Int Rev Cytol. 73, 533-545 (2001).</li><li>Maurer, J., Fuchs, S., J&#228;ger, R., Kurz, B., Sommer, L., Schorle, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+and+controlled+differentiation+of+neural+crest+stem+cell+lines+using+conditional+transgenesis.">Establishment and controlled differentiation of neural crest stem cell lines using conditional transgenesis.</a> Differentiation. 75, 890-891 (2007).</li><li>Wu, Y. Y., Mujtaba, T., Rao, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+stem+and+precursor+cells+from+fetal+tissue.">Isolation of stem and precursor cells from fetal tissue.</a> Methods Mol Biol. 198, 29-40 (2002).</li></ol>

No conflicts of interest declared.

This protocol is based on modifications of procedures that have been described in the past10,11. In addition to former publications we here show the individual different steps of the process more expanded. This supports the experimenter with important details assuring correct proceedings and reliable outcomes. Further, as the dissection process is an essential part of CEE extraction we describe the procedure of taking the embryos out of the yolk sack in every detail. There are several important points to note ...

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		<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>11 days incubated chicken eggs</td>
<td>&nbsp;</td>
<td>S&ouml;rries-Trockels Vermehrungszucht GmbH &amp; Co.KG</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Alcoholic disinfection spray</td>
<td>&nbsp;</td>
<td>Sch&uuml;lke &amp; Mayr GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>DMEMGlutamax</td>
<td>&nbsp;</td>
<td>GIBCO Invitrogen</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Syringe sterile (60 ml)</td>
<td>&nbsp;</td>
<td>BD Biosciences</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Tubes sterile (50; 15 ml)</td>
<td>&nbsp;</td>
<td>Greiner Bio-One GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Pipet tips sterile</td>
<td>&nbsp;</td>
<td>Starlab GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Hyaluronidase typeIV-S</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Milipore stericups sterile (0.45; 0.22 &mu;l)</td>
<td>&nbsp;</td>
<td>Fisher Scientific AG</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Pipettes sterile (25; 10; 5 ml)</td>
<td>&nbsp;</td>
<td>Greiner Bio-One GmbH</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Centrifuge L5-50</td>
<td>&nbsp;</td>
<td>Rotor type Ti-45</td>
<td>&nbsp;</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

production of chick embryo extract for the cultivation of murine neural crest stem cells

The neural crest arises from the neuro-ectoderm during embryogenesis and persists only temporarily. Early experiments already proofed pluripotent progenitor cells to be an integral part of the neural crest1. Phenotypically, neural crest stem cells (NCSC) are defined by simultaneously expressing p75 (low-affine nerve growth factor receptor, LNGFR) and SOX10 during their migration from the neural crest2,3,4,5. These progenitor cells can differentiate into smooth muscle cells, chromaffin cells, neurons and glial cells, as well as melanocytes, cartilage and bone6,7,8,9. To cultivate NCSC in vitro, a special neural crest stem cell medium (NCSCM) is required10. The most complex part of the NCSCM is the preparation of chick embryo extract (CEE) representing an essential source of growth factors for the NCSC as well as for other types of neural explants. Other NCSCM ingredients beside CEE are commercially available. Producing CCE using laboratory standard equipment it is of high importance to know about the challenging details as the isolation, maceration, centrifugation, and filtration processes. In this protocol we describe accurate techniques to produce a maximized amount of pure and high quality CEE.

Watch this Scientific Journal Video about Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells at JoVE.com

Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells

To cultivate neural crest stem cells (NCSC) in vitro, a special medium (NCSCM) is required. Essential part of NCSCM is chick embryo extract (CEE). We here describe accurate techniques to produce a maximized amount of pure and high quality CEE, including details as the isolation, maceration, centrifugation, and filtration processes.

The neural crest arises from the neuro-ectoderm during embryogenesis and persists only temporarily. Early experiments already proofed pluripotent ...

production-chick-embryo-extract-for-cultivation-murine-neural-crest

Research

JoVE Journal

Neuroscience

12.6K Views.  University Children's Hospital Essen. To cultivate neural crest stem cells (NCSC) in vitro, a special medium (NCSCM) is required. Essential part of NCSCM is chick embryo extract (CEE). We here describe accurate techniques to produce a maximized amount of pure and high quality CEE, including details as the isolation, maceration, centrifugation, and filtration processes.

Video: Production of Chick Embryo Extract for the Cultivation of Murine Neural Crest Stem Cells

Isolation and Culture of Neural Crest Stem Cells from Human Hair Follicles

Hair follicles undergo lifelong growth and hair cycle is a well-controlled process involving stem cell proliferation and quiescence. Hair bulge is a well-characterized niche for adult stem cells1. This segment of the outer root sheath contains a number of different types of stem cells, including epithelial stem cells2, melanocyte stem cells3 and neural crest like stem cells4-7. Hair follicles represent an accessible and rich source for different types of human stem cells. We and others have isolated neural crest stem cells (NCSCs) from human fetal and adult hair follicles4,5. These human stem cells are label-retaining cells and are capable of self-renewal through asymmetric cell division in vitro. They express immature neural crest cell markers but not differentiation markers. Our expression profiling study showed that they share a similar gene expression pattern with murine skin immature neural crest cells. They exhibit clonal multipotency that can give rise to myogenic, melanocytic, and neuronal cell lineages after in vitro clonal single cell culture. Differentiated cells not only acquire lineage-specific markers but also demonstrate appropriate functions in ex vivo conditions. In addition, these NCSCs show differentiation potential toward mesenchymal lineages. Differentiated neuronal cells can persist in mouse brain and retain neuronal differentiation markers. It has been shown that hair follicle derived NCSCs can help nerve regrowth, and they improve motor function in mice transplanted with these stem cells following transecting spinal cord injury8. Furthermore, peripheral nerves have been repaired with stem cell grafts9, and implantation of skin-derived precursor cells adjacent to crushed sciatic nerves has resulted in remyelination10. Therefore, the hair follicle/skin derived NCSCs have already shown promising results for regenerative therapy in preclinical models.
Somatic cell reprogramming to induced pluripotent stem (iPS) cells has shown enormous potential for regenerative medicine. However, there are still many issues with iPS cells, particularly the long term effect of oncogene/virus integration and potential tumorigenicity of pluripotent stem cells have not been adequately addressed. There are still many hurdles to be overcome before iPS cells can be used for regenerative medicine. Whereas the adult stem cells are known to be safe and they have been used clinically for many years, such as bone marrow transplant. Many patients have already benefited from the treatment. Autologous adult stem cells are still preferred cells for transplantation. Therefore, the readily accessible and expandable adult stem cells in human skin/hair follicles are a valuable source for regenerative medicine.

This article presents a robust protocol for isolation and culture of neural crest stem cells from human hair follicles.

Hair follicles undergo lifelong growth and hair cycle is a well-controlled process involving stem cell proliferation and quiescence. Hair bulge is a ...

Isolation and Culture of Neural Crest Cells from Embryonic Murine Neural Tube

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to mesenchymal transition (EMT) and migrates throughout the embryo, giving rise to diverse cell types 1-3. NC also has the unique ability to influence the differentiation and maturation of target organs4-6. When explanted in vitro, NC progenitors undergo self-renewal, migrate and differentiate into a variety of tissue types including neurons, glia, smooth muscle cells, cartilage and bone. 
NC multipotency was first described from explants of the avian neural tube7-9. In vitro isolation of NC cells facilitates the study of NC dynamics including proliferation, migration, and multipotency. Further work in the avian and rat systems demonstrated that explanted NC cells retain their NC potential when transplanted back into the embryo10-13. Because these inherent cellular properties are preserved in explanted NC progenitors, the neural tube explant assay provides an attractive option for studying the NC in vitro. 
To attain a better understanding of the mammalian NC, many methods have been employed to isolate NC populations. NC-derived progenitors can be cultured from post-migratory locations in both the embryo and adult to study the dynamics of post-migratory NC progenitors11,14-20, however isolation of NC progenitors as they emigrate from the neural tube provides optimal preservation of NC cell potential and migratory properties13,21,22. Some protocols employ fluorescence activated cell sorting (FACS) to isolate a NC population enriched for particular progenitors11,13,14,17. However, when starting with early stage embryos, cell numbers adequate for analyses are difficult to obtain with FACS, complicating the isolation of early NC populations from individual embryos. Here, we describe an approach that does not rely on FACS and results in an approximately 96% pure NC population based on a Wnt1-Cre activated lineage reporter23. 
The method presented here is adapted from protocols optimized for the culture of rat NC11,13. The advantages of this protocol compared to previous methods are that 1) the cells are not grown on a feeder layer, 2) FACS is not required to obtain a relatively pure NC population, 3) premigratory NC cells are isolated and 4) results are easily quantified. Furthermore, this protocol can be used for isolation of NC from any mutant mouse model, facilitating the study of NC characteristics with different genetic manipulations. The limitation of this approach is that the NC is removed from the context of the embryo, which is known to influence the survival, migration and differentiation of the NC2,24-28.

Isolation of embryonic neural crest from the neural tube facilitates the use of in vitro methods for studying migration, self-renewal, and multipotency of neural crest.

The embryonic neural crest (NC) is a multipotent progenitor population that originates at the dorsal aspect of the neural tube, undergoes an epithelial to ...

Electroporation of the Hindbrain to Trace Axonal Trajectories and Synaptic Targets in the Chick Embryo

Electroporation of the chick embryonic neural tube has many advantages such as being quick and efficient for the expression of foreign genes into neuronal cells. In this manuscript we provide a method that demonstrates uniquely how to electroporate DNA into the avian hindbrain at E2.75 in order to specifically label a subset of neuronal progenitors, and how to follow their axonal projections and synaptic targets at much advanced stages of development, up to E14.5. We have utilized novel genetic tools including specific enhancer elements, Cre/Lox - based plasmids and the PiggyBac-mediated DNA transposition system to drive GFP expression in a subtype of hindbrain cells (the dorsal most subgroup of interneurons, dA1). Axonal trajectories and targets of dA1 axons are followed at early and late embryonic stages at various brainstem regions. This strategy contributes advanced techniques for targeting cells of interest in the embryonic hindbrain and for tracing circuit formation at multiple stages of development.

How neuronal networks are established in the embryonic brain is a fundamental question in developmental neurobiology. Here we combined an electroporation technique with novel genetic tools, such as Cre/Lox&#x2013;plasmids and PiggyBac-mediated DNA transposition system in the avian hindbrain to label dorsal interneurons and track their axonal projections and synaptic targets at various developmental stages.

Electroporation of  the chick embryonic neural tube has many advantages such as being quick and efficient  for the expression of foreign genes into ...

Feeder-free Derivation of Neural Crest Progenitor Cells from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) have great potential for studying human embryonic development, for modeling human diseases in the dish and as a source of transplantable cells for regenerative applications after disease or accidents. Neural crest (NC) cells are the precursors for a large variety of adult somatic cells, such as cells from the peripheral nervous system and glia, melanocytes and mesenchymal cells. They are a valuable source of cells to study aspects of human embryonic development, including cell fate specification and migration. Further differentiation of NC progenitor cells into terminally differentiated cell types offers the possibility to model human diseases in vitro, investigate disease mechanisms and generate cells for regenerative medicine. This article presents the adaptation of a currently available in vitro differentiation protocol for the derivation of NC cells from hPSCs. This new protocol requires 18 days of differentiation, is feeder-free, easily scalable and highly reproducible among human embryonic stem cell (hESC) lines as well as human induced pluripotent stem cell (hiPSC) lines. Both old and new protocols yield NC cells of equal identity.

Neural crest (NC) cells derived from human pluripotent stem cells (hPSC) have great potential for modeling human development and disease and for cell replacement therapies. Here, a feeder-free adaptation of the currently widely used in vitro differentiation protocol for the derivation of NC cells from hPSCs is presented.

Human pluripotent stem cells (hPSCs) have great potential for studying human embryonic development, for modeling human diseases in the dish and as a ...

Enumeration of Neural Stem Cells Using Clonal Assays

Neural stem cells (NSCs) have the ability to self-renew and generate the three major neural lineages &#8212; astrocytes, neurons and oligodendrocytes. NSCs and neural progenitors (NPs) are commonly cultured in vitro as neurospheres. This protocol describes in detail how to determine the NSC frequency in a given cell population under clonal conditions. The protocol begins with the seeding of the cells at a density that allows for the generation of clonal neurospheres. The neurospheres are then transferred to chambered coverslips and differentiated under clonal conditions in conditioned medium, which maximizes the differentiation potential of the neurospheres. Finally, the NSC frequency is calculated based on neurosphere formation and multipotency capabilities. Utilities of this protocol include the evaluation of candidate NSC markers, purification of NSCs, and the ability to distinguish NSCs from NPs. This method takes 13 days to perform, which is much shorter than current methods to enumerate NSC frequency.

Neural stem cells (NSCs) refer to cells&#160;which can self-renew and differentiate into the three neural lineages. Here, we describe a protocol to determine NSC frequency in a given cell population using neurosphere formation and differentiation under clonal conditions.

Neural stem cells (NSCs) have the ability to self-renew and generate the three major neural lineages &#8212; astrocytes, neurons and oligodendrocytes. ...

Development of a Refined Protocol for Trans-scleral Subretinal Transplantation of Human Retinal Pigment Epithelial Cells into Rat Eyes

Degenerative retinal diseases such as age-related macular degeneration (AMD) are the leading cause of irreversible vision loss worldwide. AMD is characterized by the degeneration of retinal pigment epithelial (RPE) cells, which are a monolayer of cells functionally supporting and anatomically wrapping around the neural retina. Current pharmacological treatments for the non-neovascular AMD (dry AMD) only slow down the disease progression but cannot restore vision, necessitating studies aimed at identifying novel therapeutic strategies. Replacing the degenerative RPE cells with healthy cells holds promise to treat dry AMD in the future. Extensive preclinical studies of stem cell replacement therapies for AMD involve the transplantation of stem cell-derived RPE cells into the subretinal space of animal models, in which the subretinal injection technique is applied. The approach most frequently used in these preclinical animal studies is through the trans-scleral route, which is made difficult by the lack of direct visualization of the needle end and can often result in retinal damage. An alternative approach through the vitreous allows for direct observation of the needle end position, but it carries a high risk of surgical traumas as more eye tissues are disturbed. We have developed a less risky and reproducible modified trans-scleral injection method that uses defined needle angles and depths to successfully and consistently deliver RPE cells into the rat subretinal space and avoid excessive retinal damage. Cells delivered in this manner have been previously demonstrated to be efficacious in the Royal College of Surgeons (RCS) rat for at least 2 months. This technique can be used not only for cell transplantation but also for delivery of small molecules or gene therapies.

Subretinal injection has been widely applied in preclinical studies of stem cell replacement therapy for age-related macular degeneration. In this visualized article, we describe a less risky, reproducible and precisely modified subretinal injection technique via the trans-scleral approach to deliver cells into rat eyes.

Degenerative retinal diseases such as age-related macular degeneration (AMD) are the leading cause of irreversible vision loss worldwide. AMD is ...

Organotypic Cultures of Adult Human Cortex as an Ex vivo Model for Human Stem Cell Transplantation and Validation

Neurodegenerative disorders are common and heterogeneous in terms of their symptoms and cellular affectation, making their study complicated due to the lack of proper animal models that fully mimic human diseases and the poor availability of post-mortem human brain tissue. Adult human nervous tissue culture offers the possibility to study different aspects of neurological disorders. Molecular, cellular, and biochemical mechanisms could be easily addressed in this system, as well as testing and validating drugs or different treatments, such as cell-based therapies. This method combines long-term organotypic cultures of the adult human cortex, obtained from epileptic patients undergoing resective surgery, and ex vivo intracortical transplantation of induced pluripotent stem cell-derived cortical progenitors. This method will allow the study of cell survival, neuronal differentiation, the formation of synaptic inputs and outputs, and the electrophysiological properties of human-derived cells after transplantation into intact adult human cortical tissue. This approach is an important step prior to the development of a 3D human disease modeling platform that will bring basic research closer to the clinical translation of stem cell-based therapies for patients with different neurological disorders and allow the development of new tools for reconstructing damaged neural circuits.

Organotypic Cultures of Adult Human Cortex as an Ex vivo Model for Human Stem Cell Transplantation and Validation

This protocol describes long-term organotypic cultures of adult human cortex combined with ex vivo intracortical transplantation of induced pluripotent stem cell-derived cortical progenitors, which present a novel methodology to further test stem cell-based therapies for human neurodegenerative disorders.

Neurodegenerative disorders are common and heterogeneous in terms of their symptoms and cellular affectation, making their study complicated due to the ...

Derivation of Enteric Neurons from Human Pluripotent Stem Cells

Differentiation of Enteric Nervous System Lineages from Human Pluripotent Stem Cells

The human enteric nervous system, ENS, is a large network of glial and neuronal cell types with remarkable neurotransmitter diversity. The ENS controls bowel motility, enzyme secretion, and nutrient absorption and interacts with the immune system and the gut microbiome. Consequently, developmental and acquired defects of the ENS are responsible for many human diseases and may contribute to symptoms of Parkinson's disease. Limitations in animal model systems and access to primary tissue pose significant experimental challenges in studies of the human ENS. Here, a detailed protocol is presented for effective in vitro derivation of the ENS lineages from human pluripotent stem cells, hPSC, using defined culture conditions. Our protocol begins with directed differentiation of hPSCs to enteric neural crest cells within 15 days and yields diverse subtypes of functional enteric neurons within 30 days. This platform provides a scalable resource for developmental studies, disease modeling, drug discovery, and regenerative applications.

Author Spotlight: Robust Culture of Human Enteric Neurons from Human Pluripotent Stem Cells

Deriving enteric nervous system (ENS) lineages from human pluripotent stem cells (hPSC) provides a scalable source of cells to study ENS development and disease, and to use in regenerative medicine. Here, a detailed in vitro protocol to derive enteric neurons from hPSCs using chemically defined culture conditions is presented.

The human enteric nervous system, ENS, is a large network of glial and neuronal cell types with remarkable neurotransmitter diversity. The ENS controls ...

Efficient Nucleofection of NSCs Isolated from the Murine Subventricular Zone

Isolation, Expansion, and Nucleofection of Neural Stem Cells from Adult Murine Subventricular Zone

Isolation and expansion of neural stem cells (NSCs) from the subventricular zone (SVZ) of the adult mouse brain can be achieved in a medium supplemented with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) as mitogens, producing clonal aggregates known as neurospheres. This in vitro system is a valuable tool for studying NSC potential. Transfection of siRNAs or genes carried in plasmids can be used to induce perturbations to gene expression and study NSC biology. However, the exogenous nucleic acid delivery to NSC cultures is challenging due to the low efficiency of central nervous system (CNS) cells transfection. Here, we present an improved nucleofection system that achieves high efficiency of gene delivery in expanded NSCs from adult murine SVZ. We demonstrate that this relatively simple method enhances gene perturbation in adult NSCs, surpassing traditional transfection protocols with survival rates exceeding 80%. Moreover, this method can also be applied in primary isolated NSCs, providing a crucial advancement in gene function studies through gene expression manipulation via knockdown or overexpression in neurosphere cultures.

Author Spotlight: Improved Nucleofection for High-Efficiency Gene Delivery in Murine Subventricular Zone-Derived Neural Stem Cell Cultures

Here, we describe a nucleofection system designed to enhance gene delivery efficiency in expanded neural stem cells (NSCs) isolated from the adult murine subventricular zone. The findings demonstrate that this method significantly improves gene perturbation in NSCs, surpassing the effectiveness of traditional transfection protocols and enhancing cell survival rate.

Isolation and expansion of neural stem cells (NSCs) from the subventricular zone (SVZ) of the adult mouse brain can be achieved in a medium supplemented ...