The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. This research was performed while the authors Alberto Mu&#241;iz, Ramesh R Kaini, Whitney A Greene and Jae-Hyek Choi held a National Research Council Postdoctoral Research Associateship at the USAISR. This work was supported by U.S. Army Clinical Rehabilitative Medicine Research Program (CRMRP) and Military Operational Medicine Research Program (MOMRP).

1. Preparation of Culture Reagents and Culture Plates
<ol>
	<li>Prepare feeder-free stem cell culture medium by adding 100 ml of 5x serum-free supplement to 400 ml of stem cell basal medium. The medium is stable at 4 &#176;C for up to 2 weeks and at -20 &#176;C for 6 months.</li>
	<li>Add 10 &#181;M solution of rho-associated, coiled-coil containing protein kinase (Rock) inhibitor (Y-27362) to commercially available embryoid body (EB) formation medium.</li>
	<li>Prepare differentiation medium by adding 0.1 mM &#946;-me...

<ol>
	<li>Takahashi, K., 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=Induction+of+pluripotent+stem+cells+from+fibroblast+cultures.">Induction of pluripotent stem cells from fibroblast cultures.</a> Nat Protoc. 2 (12), 3081-3089 (2007).</li><li>Reubinoff, B. E., 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=Embryonic+stem+cell+lines+from+human+blastocysts:+somatic+differentiation+in+vitro.">Embryonic stem cell lines from human blastocysts: somatic differentiation in vitro.</a> Nat Biotechnol. 18 (4), 399-404 (2000).</li><li>Thomson, J. A., 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=Embryonic+stem+cell+lines+derived+from+human+blastocysts.">Embryonic stem cell lines derived from human blastocysts.</a> Science. 282 (5391), 1145-1147 (1998).</li><li>Takahashi, K., Yamanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+pluripotent+stem+cells+from+mouse+embryonic+and+adult+fibroblast+cultures+by+defined+factors.">Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors.</a> Cell. 126 (4), 663-676 (2006).</li><li>Yu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induced+pluripotent+stem+cell+lines+derived+from+human+somatic+cells.">Induced pluripotent stem cell lines derived from human somatic cells.</a> Science. 318 (5858), 1917-1920 (2007).</li><li>Buchholz, D. E., 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=Derivation+of+functional+retinal+pigmented+epithelium+from+induced+pluripotent+stem+cells.">Derivation of functional retinal pigmented epithelium from induced pluripotent stem cells.</a> Stem Cells. 27 (10), 2427-2434 (2009).</li><li>Ukrohne, T. U., 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=Generation+of+retinal+pigment+epithelial+cells+from+small+molecules+and+OCT4+reprogrammed+human+induced+pluripotent+stem+cells.">Generation of retinal pigment epithelial cells from small molecules and OCT4 reprogrammed human induced pluripotent stem cells.</a> Stem Cells Transl Med. 1 (2), 96-109 (2012).</li><li>Subba, R. M., Sasikala, M., Nageshwar, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thinking+outside+the+liver:+induced+pluripotent+stem+cells+for+hepatic+applications.">Thinking outside the liver: induced pluripotent stem cells for hepatic applications.</a> World J Gastroenterol. 19 (22), 3385-3396 (2013).</li><li>Yoshida, Y., Yamanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=iPS+cells:+a+source+of+cardiac+regeneration.">iPS cells: a source of cardiac regeneration.</a> J Mol Cell Cardiol. 50 (2), 327-332 (2011).</li><li>Mak, S. K., 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=Small+molecules+greatly+improve+conversion+of+human-induced+pluripotent+stem+cells+to+the+neuronal+lineage.">Small molecules greatly improve conversion of human-induced pluripotent stem cells to the neuronal lineage.</a> Stem Cells Int. 2012, 140427 (2012).</li><li>Bauwens, C. 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=Control+of+human+embryonic+stem+cell+colony+and+aggregate+size+heterogeneity+influences+differentiation+trajectories.">Control of human embryonic stem cell colony and aggregate size heterogeneity influences differentiation trajectories.</a> Stem Cells. 26 (9), 2300-2310 (2008).</li><li>Cour la, M., Tezel, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Retinal+Pigment+Epithelium.">The Retinal Pigment Epithelium.</a> Advances in Organ Biology. 10, 253-273 (2006).</li><li>Vaajassari, V., 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=Toward+the+defined+and+xeno-free+differentiation+of+functional+human+pluripotent+stem+cell-derived+retinal+pigment+epithelial+cells.">Toward the defined and xeno-free differentiation of functional human pluripotent stem cell-derived retinal pigment epithelial cells.</a> Mol Vis. 17, 558-575 (2011).</li><li>Carr, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protective+effects+of+human+iPS-derived+retinal+pigment+epithelium+cell+transplantation+in+the+retinal+dystrophic+rat.">Protective effects of human iPS-derived retinal pigment epithelium cell transplantation in the retinal dystrophic rat.</a> PLoS One. 4 (12), e8152 (2009).</li><li>Muniz, A., 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=Retinoid+uptake,+processing,+and+secretion+in+human+iPS-RPE+support+the+visual+cycle.">Retinoid uptake, processing, and secretion in human iPS-RPE support the visual cycle.</a> Invest Ophthalmol Vis Sci. 55 (1), 198-209 (2014).</li><li>Meyer, J. S., 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=Modeling+early+retinal+development+with+human+embryonic+and+induced+pluripotent+stem+cells.">Modeling early retinal development with human embryonic and induced pluripotent stem cells.</a> Proc Natl Acad Sci U S A. 106 (39), 16698-16703 (2009).</li><li>Bratt-Leal, A. M., Carpenedo, R. L., McDevitt, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+the+embryoid+body+microenvironment+to+direct+embryonic+stem+cell+differentiation.">Engineering the embryoid body microenvironment to direct embryonic stem cell differentiation.</a> Biotechnol Prog. 25 (1), 43-51 (2009).</li><li>Kurosawa, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+for+inducing+embryoid+body+formation:+in+vitro+differentiation+system+of+embryonic+stem+cells.">Methods for inducing embryoid body formation: in vitro differentiation system of embryonic stem cells.</a> J Biosci Bioeng. 103 (5), 389-398 (2007).</li><li>Itskovitz-Eldor, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiation+of+human+embryonic+stem+cells+into+embryoid+bodies+compromising+the+three+embryonic+germ+layers.">Differentiation of human embryonic stem cells into embryoid bodies compromising the three embryonic germ layers.</a> Mol Med. 6 (2), 88-95 (2000).</li><li>Ng, E. S., 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=Forced+aggregation+of+defined+numbers+of+human+embryonic+stem+cells+into+embryoid+bodies+fosters+robust,+reproducible+hematopoietic+differentiation.">Forced aggregation of defined numbers of human embryonic stem cells into embryoid bodies fosters robust, reproducible hematopoietic differentiation.</a> Blood. 106 (5), 1601-1603 (2005).</li><li>Maminishkis, A., 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=Confluent+monolayers+of+cultured+human+fetal+retinal+pigment+epithelium+exhibit+morphology+and+physiology+of+native+tissue.">Confluent monolayers of cultured human fetal retinal pigment epithelium exhibit morphology and physiology of native tissue.</a> Invest Ophthalmol Vis Sci. 47 (8), 3612-3624 (2006).</li></ol>

To realize the full promise of pluripotent stem cells for cell therapy, it is necessary to regulate their differentiation in a consistent and reproducible way. This report describes protocols to form size-controlled EBs using microwell plate technology, initiate differentiation toward RPE and identify protein and gene markers of RPE. To synchronize the in vitro differentiation, homogenous sizes of EBs were formed by known numbers of iPS cells centrifuged in microwell plates by forced aggregation. Immunocytochemi...

Induced pluripotent stem (iPS) cells are a type of pluripotent stem cell derived by reprogramming adult cells with extrinsic factors1. In contrast, embryonic stem cells (ESCs), another type of pluripotent stem cell, are generated from the inner cell mass of the blastocyst2-3. Despite their different origins, iPS cells and ESCs are comparable in their unlimited capacity to replicate in vitro and in their capacity to differentiate into any cell type4-5. These characteristics of iPS cells make them ideal candidates for applications in personalized regenerative medicine. Recent research efforts are focused on developing robust differentiation protocols for producing specialized adult cells including retinal pigment epithelium (RPE)6-11.
For potential clinical applications of iPS derived cells, a directed differentiation for that specific cell type is essential. There are various methods published for directed differentiation of both ESCs and iPS cells into RPE that varies greatly in their efficiency6-7, 12-16. We still do not know many of the molecular events that govern the cell/tissue fate during development or differentiation. In recent years, efforts have been made to develop the differentiation protocol that can mimic the embryological development as much as possible. During the blastocyst phase, uncommitted population of stem cells are together in a three dimensional microenvironment. So, various strategies were applied to make the ESC/iPS cells assembled together and grow them in three dimensions. These stem cell aggregates are called embryoid bodies (EBs). Studies have shown that EB differentiation of stem cells mimic early stage of embryo development and can spontaneously give rise to primitive endoderm on its exterior surface. Later, as EB development progresses, differentiated cell phenotypes of all three germ lineages appear17-18. Therefore, EBs based differentiation protocols have attracted a lot of attention for in vitro differentiation of ESC/iPS cells and are a good candidate for RPE generation from pluripotent stem cells13.
EBs can be made using several methods from ESC/iPS cells. Initially, EBs were made by scraping off adherent colonies and maintaining them in non-adherent suspension culture. However, this approach yields heterogeneous population of EBs that causes low reproducibility. Hanging drop cell culture and microwell based EBs formation are other popular techniques for EBs formation which yield homogenous EBs of defined sizes that are highly reproducible. Furthermore, the microwell technique can yield large number of aggregates with less effort.
Differentiation of cells within EBs is regulated by a multiplex of morphogenic cues from the extracellular and intracellular microenvironment. In contrast to differentiation in a monolayer format, EBs provide a platform for complex assembly of cells and intercellular signaling to occur17. Interestingly, the number of pluripotent stem cells used to make individual EBs was observed to influence the fate of cells. For example, in a hematopoietic differentiation study of human ESCs, it was observed that 500-cell EB promoted differentiation towards myeloid lineage whereas 1,000-cell EB pushed towards erythroid lineage20. In another study, smaller EBs favored endoderm differentiation whereas larger EBs promoted towards neuro-ectoderm differentiation11, 17.
These past studies strongly suggest that the number of ESC/iPS cells used to make individual EBs affect the EBs based differentiation to any cell types. However, to our knowledge, there are no current studies that have elucidated the impact of EBs size in its propensity to differentiate towards RPE. The goal of this study is to characterize the influence of EB size on induced pluripotent stem (iPS) cells - retinal pigment epithelium (iPS-RPE) differentiation and to identify the optimum cell number to make the EBs for directed differentiation towards RPE lineage.

<table border="0" cellpadding="0" cellspacing="0" width="722">
	<tbody>
		<tr height="36">
			<td height="36" style="height:36px;width:239px;">Name of Material/ Equipment</td>
			<td style="width:183px;">Company</td>
			<td style="width:140px;">Catalog Number</td>
			<td style="width:161px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">mTeSR1 media + 5X supplement</td>
			<td>Stem Cell Technologies</td>
			<td>5850</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Y-27632 (Rock Inhibitor)</td>
			<td>Stem Cell Technologies</td>
			<td>72304</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">DMEM/F12</td>
			<td>Life Technologies</td>
			<td>11330-032</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2-Mercaptoethanol</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">M-7154</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Non essential amino acids</td>
			<td style="width:183px;">Hyclone(Fisher)</td>
			<td>SH30853.01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Knockout serum replacement</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:140px;">10828-028</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Gentamicin&#160;</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:140px;">15750-060</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">L-Glutamine</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:140px;">25030-081</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">MEM media</td>
			<td style="width:183px;">Life Technologies</td>
			<td style="width:140px;">10370-021</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">N1 supplement</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">N-6530-5ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Taurine</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">T-8691-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Hydrocortisone</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">H0888-1G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Fetal bovine serum</td>
			<td style="width:183px;">Hyclone(Fisher)</td>
			<td>SH3008803HI</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Triiodo-l-thyronine sodium&#160; salt</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">T6397</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Sodium hydroxide</td>
			<td style="width:183px;">Sigma</td>
			<td style="width:140px;">S5881</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Dispase</td>
			<td style="width:183px;">Life Technologies</td>
			<td>17105-041</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Matrigel</td>
			<td style="width:183px;">BD Biosciences</td>
			<td style="width:140px;">354277</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Phosphate buffered saline</td>
			<td style="width:183px;">Hyclone(Fisher)</td>
			<td>10010-023</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Aggrewell 400 plate</td>
			<td style="width:183px;">Stem Cell Technologies</td>
			<td>27940</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">AggreWell medium</td>
			<td>Stem Cell Technologies</td>
			<td>5893</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Accutase</td>
			<td>Stem Cell Technologies</td>
			<td>7920</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">BD Cytofix/Cytoperm Fixation/Permeabilization Kit</td>
			<td>BD Biosciences</td>
			<td>554714</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Mouse Anti-PAX6 antibody</td>
			<td colspan="2">Developmental Studies Hybridoma Bank</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Rabbit Anti- RX antibody</td>
			<td>Abcam</td>
			<td>Ab23340</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Mouse&#160; Anti-MITF antibody</td>
			<td>Thermo Scientific</td>
			<td>MS-772-P</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Rabbit Anti-ZO-1 antibody</td>
			<td>Invitrogen</td>
			<td>40-2200</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">RNeasy plus mini kit</td>
			<td>Qiagen</td>
			<td>74134</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">PCR master mix</td>
			<td>promega</td>
			<td>M7502</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">High capacity RNA to c DNA kit</td>
			<td style="width:183px;">Life Technologies</td>
			<td>4387406</td>
			<td></td>
		</tr>
	</tbody>
</table>

deriving retinal pigment epithelium (rpe) from induced pluripotent stem (ips) cells by different sizes of embryoid bodies

Pluripotent stem cells possess the ability to proliferate indefinitely and to differentiate into almost any cell type. Additionally, the development of techniques to reprogram somatic cells into induced pluripotent stem (iPS) cells has generated interest and excitement towards the possibility of customized personal regenerative medicine. However, the efficiency of stem cell differentiation towards a desired lineage remains low. The purpose of this study is to describe a protocol to derive retinal pigment epithelium (RPE) from iPS cells (iPS-RPE) by applying a tissue engineering approach to generate homogenous populations of embryoid bodies (EBs), a common intermediate during in vitro differentiation. The protocol applies the formation of specific size of EBs using microwell plate technology. The methods for identifying protein and gene markers of RPE by immunocytochemistry and reverse-transcription polymerase chain reaction (RT-PCR) are also explained. Finally, the efficiency of differentiation in different sizes of EBs monitored by fluorescence-activated cell sorting (FACS) analysis of RPE markers is described. These techniques will facilitate the differentiation of iPS cells into RPE for future applications.

In this experiment, iPS cells were cultured and differentiated into the RPE lineage from EBs. EBs of controlled sizes were formed using microwell plates. As seen in Figure 1 EB formation was homogenous in the microwell plates. These EBs were then collected and plated on 6-well plates (Figure 2).
RPE can be identified by their classical hexagonal morphology, pigmentation, and expression of RPE markers. After 12 weeks of culture, the 200-cell EBs had developed a...

Watch this Scientific Journal Video about Deriving Retinal Pigment Epithelium RPE from Induced Pluripotent Stem iPS Cells by Different Sizes of Embryoid Bodies at JoVE.com

Deriving Retinal Pigment Epithelium RPE from Induced Pluripotent Stem iPS Cells by Different Sizes of Embryoid Bodies

The objective of this report is to describe the protocols to derive the retinal pigment epithelium (RPE) from induced pluripotent stem (iPS) cells using different sizes of embryoid bodies.

Deriving Retinal Pigment Epithelium (RPE) from Induced Pluripotent Stem (iPS) Cells by Different Sizes of Embryoid Bodies

Pluripotent stem cells possess the ability to proliferate indefinitely and to differentiate into almost any cell type. Additionally, the development of ...

deriving-retinal-pigment-epithelium-rpe-from-induced-pluripotent-stem

Research

JoVE Journal

Developmental Biology

10.5K vues.  U.S. Army Institute of Surgical Research.  L'objectif de ce rapport est de décrire les protocoles de dériver l'épithélium pigmentaire rétinien (EPR) à partir de cellules souches pluripotentes induites (iPS) en utilisant différentes tailles de corps embryoïdes. 

Vidéo: Deriving Retinal Pigment Epithelium RPE from Induced Pluripotent Stem iPS Cells by Different Sizes of Embryoid Bodies

Efficient Derivation of Retinal Pigment Epithelium Cells from Stem Cells

No cure has been discovered for age-related macular degeneration (AMD), the leading cause of vision loss in people over the age of 55. AMD is complex multifactorial disease with an unknown etiology, although it is largely thought to occur due to death or dysfunction of the retinal pigment epithelium (RPE), a monolayer of cells that underlies the retina and provides critical support for photoreceptors. RPE cell replacement strategies may hold great promise for providing therapeutic relief for a large subset of AMD patients, and RPE cells that strongly resemble primary human cells (hRPE) have been generated in multiple independent labs, including our own. In addition, the uses for iPS-RPE are not limited to cell-based therapies, but also have been used to model RPE diseases. These types of studies may not only elucidate the molecular bases of the diseases, but also serve as invaluable tools for developing and testing novel drugs. We present here an optimized protocol for directed differentiation of RPE from stem cells. Adding nicotinamide and either Activin A or IDE-1, a small molecule that mimics its effects, at specific time points, greatly enhances the yield of RPE cells. Using this technique we can derive large numbers of low passage RPE in as early as three months.

Stem cell-derived retinal pigment epithelium (RPE) cells may be used for multiple applications including cell-based therapies for retinal degeneration, disease modeling, and drug studies. Here we present a simple protocol for reproducibly deriving RPE from stem cells.

No cure has been discovered for age-related macular degeneration  (AMD), the leading cause of vision loss in people over the age of 55. AMD is complex ...

Analysis of Retinoic Acid-induced Neural Differentiation of Mouse Embryonic Stem Cells in Two and Three-dimensional Embryoid Bodies

Mouse embryonic stem cells (ESCs) isolated from the inner mass of the blastocyst (typically at day E3.5), can be used as in vitro model system for studying early embryonic development. In the absence of leukemia inhibitory factor (LIF), ESCs differentiate by default into neural precursor cells. They can be amassed into a three dimensional (3D) spherical aggregate termed embryoid body (EB) due to its similarity to the early stage embryo. EBs can be seeded on fibronectin-coated coverslips, where they expand by growing two dimensional (2D) extensions, or implanted in 3D collagen matrices where they continue growing as spheroids, and differentiate into the three germ layers: endodermal, mesodermal, and ectodermal. The 3D collagen culture mimics the in vivo environment more closely than the 2D EBs. The 2D EB culture facilitates analysis by immunofluorescence and immunoblotting to track differentiation. We have developed a two-step neural differentiation protocol. In the first step, EBs are generated by the hanging-drop technique, and, simultaneously, are induced to differentiate by exposure to retinoic acid (RA). In the second step, neural differentiation proceeds in a 2D or 3D format in the absence of RA.

We describe a technique for using murine embryonic stem cells for generating two or three dimensional embryoid bodies. We then explain how to induce neural differentiation of the embryoid body cells by retinoic acid, and how to analyze their state of differentiation by progenitor cell marker immunofluorescence and immunoblotting.

Mouse embryonic stem cells (ESCs) isolated from the inner mass of the blastocyst (typically at day E3.5), can be used as in vitro model system for ...

Differentiating Chondrocytes from Peripheral Blood-derived Human Induced Pluripotent Stem Cells

In this study, we used peripheral blood cells (PBCs) as seed cells to produce chondrocytes via induced pluripotent stem cells (iPSCs) in an integration-free method. Following embryoid body (EB) formation and fibroblastic cell expansion, the iPSCs are induced for chondrogenic differentiation for 21 days under serum-free and xeno-free conditions. After chondrocyte induction, the phenotypes of the cells are evaluated by morphological, immunohistochemical, and biochemical analyses, as well as by the quantitative real-time PCR examination of chondrogenic differentiation markers. The chondrogenic pellets show positive alcian blue and toluidine blue staining. The immunohistochemistry of collagen II and X staining is also positive. The sulfated glycosaminoglycan (sGAG) content and the chondrogenic differentiation markers COLLAGEN 2 (COL2), COLLAGEN 10 (COL10), SOX9, and AGGRECAN are significantly upregulated in chondrogenic pellets compared to hiPSCs and fibroblastic cells. These results suggest that PBCs can be used as seed cells to generate iPSCs for cartilage repair, which is patient-specific and cost-effective.

We present a protocol to generate a chondrogenic lineage from human peripheral blood (PB) via induced pluripotent stem cells (iPSCs) using an integration-free method, which includes embryoid body (EB) formation, fibroblastic cells expansion, and chondrogenic induction.

In this study, we used peripheral blood cells (PBCs) as seed cells to produce chondrocytes via induced pluripotent stem cells (iPSCs) in an ...

Chondrogenic Pellet Formation from Cord Blood-derived Induced Pluripotent Stem Cells

Human articular cartilage lacks the ability to repair itself. Cartilage degeneration is thus treated not by curative but by conservative treatments. Currently, efforts are being made to regenerate damaged cartilage with ex vivo expanded chondrocytes or bone marrow-derived mesenchymal stem cells (BMSCs). However, the restricted viability and instability of these cells limit their application in cartilage reconstruction. Human induced pluripotent stem cells (hiPSCs) have received scientific attention as a new alternative for regenerative applications. With unlimited self-renewal ability and multipotency, hiPSCs have been highlighted as a new replacement cell source for cartilage repair. However, obtaining a high quantity of high-quality chondrogenic pellets is a major challenge to their clinical application. In this study, we used embryoid body (EB)-derived outgrowth cells for chondrogenic differentiation. Successful chondrogenesis was confirmed by PCR and staining with alcian blue, toluidine blue, and antibodies against collagen types I and II (COL1A1 and COL2A1, respectively). We provide a detailed method for the differentiation of cord blood mononuclear cell-derived iPSCs (CBMC-hiPSCs) into chondrogenic pellets.

Here, we propose a protocol for chondrogenic differentiation from cord blood mononuclear cell-derived human induced pluripotent stem cells.

Human articular cartilage lacks the ability to repair itself. Cartilage degeneration is thus treated not by curative but by conservative treatments. ...

Rapid, Directed Differentiation of Retinal Pigment Epithelial Cells from Human Embryonic or Induced Pluripotent Stem Cells

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing a detailed and thorough protocol is to clearly demonstrate each step and to make this readily available to researchers in the field. This protocol results in a homogenous layer of RPE with minimal or no manual dissection needed. The method presented here has been shown to be effective for induced pluripotent stem cells (iPSC) and human embryonic stem cells. Additionally, we describe methods for cryopreservation of intermediate cell banks that allow long-term storage. RPE generated using this protocol might be useful for iPSC disease-in-a-dish modeling or clinical application.

This protocol describes how to produce retinal pigment epithelial cells (RPE) from pluripotent stem cells. The method uses a combination of growth factors and small molecules to direct the differentiation of stem cells into immature RPE in fourteen days and mature, functional RPE after three months.

We describe a robust method to direct the differentiation of pluripotent stem cells into retinal pigment epithelial cells (RPE). The purpose of providing ...

Engineering Transplantation-suitable Retinal Pigment Epithelium Tissue Derived from Human Embryonic Stem Cells

Several pathological conditions of the eye affect the functionality and/or the survival of the retinal pigment epithelium (RPE). These include some forms of retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Cell therapy is one of the most promising therapeutic strategies proposed to cure these diseases, with already encouraging preliminary results in humans. However, the method of preparation of the graft has a significant impact on its functional outcomes in vivo. Indeed, RPE cells grafted as a cell suspension are less functional than the same cells transplanted as a retinal tissue. Herein, we describe a simple and reproducible method to engineer RPE tissue and its preparation for an in vivo implantation. RPE cells derived from human pluripotent stem cells are seeded on a biological support, the human amniotic membrane (hAM). Compared to artificial scaffolds, this support has the advantage of having a basement membrane that is close to the Bruch&#39;s membrane where endogenous RPE cells are attached. However, its manipulation is not easy, and we developed several strategies for its proper culturing and preparation for grafting in vivo.

We describe a method to engineer a retinal tissue composed of retinal pigment epithelial cells derived from human pluripotent stem cells cultured on top of human amniotic membranes and its preparation for grafting in animal models.

Several pathological conditions of the eye affect the functionality and/or the survival of the retinal pigment epithelium (RPE). These include some forms ...

Generation of Human Primordial Germ Cell-like Cells at the Surface of Embryoid Bodies from Primed-pluripotency Induced Pluripotent Stem Cells

Primordial germ cells (PGCs) are common precursors of all germline cells. In mouse embryos, a founding population of ~40 PGCs are induced from pluripotent epiblast cells by orchestrated exposures to cytokines, including bone morphogenetic protein 4 (Bmp4). In human embryos, the earliest PGCs have been identified on the endodermal wall of yolk sac around the end of the 3rd week of gestation, but little is known about the process of human PGC specification and their early development. To circumvent the technical and ethical barriers of studying human embryonic PGCs, surrogate cell culture models have been recently generated from pluripotent stem cells. Here, we describe a 13-day protocol for robust production of human PGC-Like Cells (hPGCLCs). Human induced pluripotent stem cells (hiPSCs) maintained in the primed pluripotency state are incubated in the 4i na&#239;ve reprogramming medium for 48 hours, dissociated to single cells, and packed into microwells. Prolonged maintenance of hiPSCs in the na&#239;ve pluripotency state causes significant chromosomal aberrations and should be avoided. hiPSCs in the microwells are maintained for an additional 24 hours in the 4i medium to form embryoid bodies (EBs), which are then cultured in low-adherence plasticware under a rocking condition in the hPGCLC induction medium containing a high concentration of recombinant human BMP4. EBs are further cultured for up to 8 days in the rocking, non-adherent condition to obtain maximum yields of hPGCLCs. By immunohistochemistry, hPGCLCs are readily detected as cells strongly expressing OCT4 in almost all EBs exclusively on their surface. When EBs are enzymatically dissociated and subjected to FACS enrichment, hPGCLCs can be collected as CD38+ cells with up to 40-45% yield.

Primordial germ cells (PGCs) are common precursors of both sperm and eggs. Human embryonic PGCs are specified from pluripotent epiblast cells through interactions of cytokines. Here, we describe a 13-day protocol of inducing human cells transcriptomally resembling PGCs at the surface of embryoid bodies from primed-pluripotency induced pluripotent stem cells.

Primordial germ cells (PGCs) are common precursors of all germline cells. In mouse embryos, a founding population of ~40 PGCs are induced from pluripotent ...

Generation of 3D Skin Organoid from Cord Blood-derived Induced Pluripotent Stem Cells

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily functions. Biomimetics is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems1. Skin biomimetics is a useful tool for in vitro disease research and in vivo regenerative medicine. Human induced pluripotent stem cells (iPSCs) have the characteristic of unlimited proliferation and the ability of differentiation to three germ layers. Human iPSCs are generated from various primary cells, such as blood cells, keratinocytes, fibroblasts, and more. Among them, cord blood mononuclear cells (CBMCs) have emerged as an alternative cell source from the perspective of allogeneic regenerative medicine. CBMCs are useful in regenerative medicine because human leukocyte antigen (HLA) typing is essential to the cell banking system. We provide a method for the differentiation of CBMC-iPSCs into keratinocytes and fibroblasts and for generation of a 3D skin organoid. CBMC-iPSC-derived keratinocytes and fibroblasts have characteristics similar to a primary cell line. The 3D skin organoids are generated by overlaying an epidermal layer onto a dermal layer. By transplanting this 3D skin organoid, a humanized mice model is generated. This study shows that a 3D human iPSC-derived skin organoid may be a novel, alternative tool for dermatologic research in vitro and in vivo.

We propose a protocol that shows how to differentiate induced pluripotent stem cell-derived keratinocytes and fibroblasts and generate a 3D skin organoid, using these keratinocytes and fibroblasts. This protocol contains an additional step of generating a humanized mice model. The technique presented here will improve dermatologic research.

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily ...

In Vitro Generation of Somite Derivatives from Human Induced Pluripotent Stem Cells

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give rise to multiple cell types, including the myotome (MYO), sclerotome (SCL), dermatome (D), and syndetome (SYN), which in turn develop into skeletal muscle, axial skeleton, dorsal dermis, and axial tendon/ligament, respectively. Therefore, the generation of SMs and their derivatives from human induced pluripotent stem cells (iPSCs) is critical to obtain pluripotent stem cells (PSCs) for application in regenerative medicine and for disease research in the field of orthopedic surgery. Although the induction protocols for MYO and SCL from PSCs have been previously reported by several researchers, no study has yet demonstrated the induction of SYN and D from iPSCs. Therefore, efficient induction of fully competent SMs remains a major challenge. Here, we recapitulate human SM patterning with human iPSCs in vitro by mimicking the signaling environment during chick/mouse SM development, and report on methods of systematic induction of SM derivatives (MYO, SCL, D, and SYN) from human iPSCs under chemically defined conditions through the presomitic mesoderm (PSM) and SM states. Knowledge regarding chick/mouse&#160;SM development was successfully applied to the induction of SMs with human iPSCs. This method could be a novel tool for studying human somitogenesis and patterning without the use of embryos and for cell-based therapy and disease modeling.

We present here a protocol for the differentiation of human induced pluripotent stem cells into each somite derivative (myotome, sclerotome, dermatome, and syndetome) in chemically defined conditions, which has applications in future disease modeling and cell-based therapies in orthopedic surgery.

In response to signals such as WNTs, bone morphogenetic proteins (BMPs), and sonic hedgehog (SHH) secreted from surrounding tissues, somites (SMs) give ...

Hemogenic Endothelium Differentiation from Human Pluripotent Stem Cells in A Feeder- and Xeno-free Defined Condition

Deriving functional hematopoietic stem and progenitor cells (HSPCs) from human pluripotent stem cells (PSCs) have been an elusive goal for autologous transplants to treat hematological and malignant disorders. Hemogenic endothelium (HE) is an amenable platform to produce functional HSPCs by transcription factors or to induce lymphocytes in a robust manner. However, current methods to derive HE are either costly or variable in yield. In this protocol, we established a cost-effective and precise method to derive HE within 4 days in a feeder- and xeno-free defined condition. The resultant HE underwent an endothelial-to-hematopoietic transition and produced CD34+CD45+ clonogenic hematopoietic progenitors. The potential capacity of our platform for generating functional HSPCs will have broad applications in disease modeling and screening for therapeutic compounds.

Here, we present a protocol to precisely form hemogenic endothelium from human pluripotent stem cells in a feeder- and xeno-free condition. This method will have broad applications in disease modeling and screening for therapeutic compounds.

Deriving functional hematopoietic stem and progenitor cells (HSPCs) from human pluripotent stem cells (PSCs) have been an elusive goal for autologous ...