This work has been supported by the Department of Internal Medicine, Division of Hematology, Washington University School of Medicine. CD was supported by T32HL007088 from the National Heart, Lung, and Blood Institute. CMS was supported by an American Society of Hematology Scholar Award.

<ol>
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I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leukosialin+(CD43)+defines+hematopoietic+progenitors+in+human+embryonic+stem+cell+differentiation+cultures.">Leukosialin (CD43) defines hematopoietic progenitors in human embryonic stem cell differentiation cultures.</a> Blood. 108 (6), 2095-2105 (2006).</li><li>Yu, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinoic+acid+enhances+the+generation+of+hematopoietic+progenitors+from+human+embryonic+stem+cell-derived+hemato-vascular+precursors.">Retinoic acid enhances the generation of hematopoietic progenitors from human embryonic stem cell-derived hemato-vascular precursors.</a> Blood. 116 (23), 4786-4794 (2010).</li><li>Zambidis, E. T., Peault, B., Park, T. S., Bunz, F., Civin, C. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+embryo+fibroblast+(MEF)+feeder+cell+preparation.">Mouse embryo fibroblast (MEF) feeder cell preparation.</a> Curr Protoc Mol Biol. Chapter 23, (2001).</li><li>La Motte-Mohs, R. N., Herer, E., Zuniga-Pflucker, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+T-cell+development+from+human+cord+blood+hematopoietic+stem+cells+by+Delta-like+1+in+vitro.">Induction of T-cell development from human cord blood hematopoietic stem cells by Delta-like 1 in vitro.</a> Blood. 105 (4), 1431-1439 (2005).</li><li>Schmitt, T. 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The authors declare that they have no competing financial interests.

This protocol describes a rapid, serum-free, stroma-free method for the differentiation of either primitive or definitive hematopoietic progenitors. Mesodermal specification of either primitive or definitive hematopoietic progenitors can be reliably achieved using our protocol, which uniquely exploits small molecule inhibitors of canonical WNT signaling. Stage-specific WNT activation by the GSK3&#946; inhibitor CHIR9902133 gives rise to definitive hematopoietic mesoderm, whereas WNT inhibition by the PORCN inhibitor IWP234 specifies primitive hematopoietic mesoderm26. Of note, this method does not robustly give rise to an engraftable HSC-like population (not shown). However, the definitive hematopoietic progenitors generated with this approach are amenable to transgene-induced engraftment potential35, highlighting their potential in future translational applications.
A crucial determinant to successful hPSC differentiation is the initial size of the EBs that are formed from hPSCs. Ideally, the EBs should be around 6 - 10 cells in size. The differentiation cultures can aberrantly specify a mixture of both programs if the EBs are too large, possibly due to improper signal activation within the EB. Differentiation cultures should be visually inspected for optimal EB size within the first 24 h of differentiation. Alternatively, if the hPSCs are completely dissociated to single cells, the hPSCs instead undergo anoikis cell death36, resulting in poor hematopoietic differentiation.
A successful differentiation will give rise to exclusively primitive hematopoietic progenitors when IWP2 is used during mesodermal specification on Days 2 and 3 of this differentiation protocol. On Day 8 of differentiation, the IWP2-derived culture should be comprised of distinct CD34+CD43&#8722;, CD34mid/lowCD43+, and CD34&#8722;CD43+ populations (Figure 2A). The CD34mid/lowCD43+ population gives rise to primitive erythroid and myeloid progenitors; while the CD34&#8722;CD43+ population primarily gives rise to erythroid progenitors with limited myeloid potential18. The primitive hematopoietic potential can be confirmed by the methylcellulose assay for the presence of EryP-CFC (Section 6), which will predominately express the embryonic globin HBE in comparison to fetal HBG26,28,37. Similarly, the presence of CD43+ hematopoietic progenitors at this stage can be reliably used to indicate the presence of primitive hematopoietic progenitors18,23,26. It should be noted that CD43 expression is not exclusive to progenitors of the primitive hematopoietic program18,23,26, and cannot be used as the sole metric to assess primitive hematopoietic potential, as the immunophenotype and NOTCH-dependence of the human EMP remains uncharacterized (reviewed in3).
When CHIR99021 is used during mesodermal patterning during days 2 and 3 of differentiation, a population of exclusively definitive hematopoietic progenitors will be specified. On Day 8 of the differentiation protocol, CHIR99021-derived cultures should be comprised of a distinctive CD34+CD43&#8722; population, with little to no CD43 expression26. The CD34+CD43&#8722; population is a heterogeneous population of endothelial cells with hematopoietic, venous, and arterial potential that can be demarcated based on CD73 and CD184 expression, with HE cells lacking the expression of both27,28. When definitive HE is isolated after undergoing a NOTCH-dependent endothelial-to-hematopoietic transition (Section 5)28 it will yield CD34+CD45+ hematopoietic progenitors that will give rise to BFU-E and myeloid cells in methylcellulose, but not EryP-CFC26,28 (Figure 2). In addition, BFU-E colonies can be isolated and assessed for globin analysis, which will predominately express the fetal globin HBG in comparison to embryonic HBE (not shown)26,28,37. In contrast, the lymphoid potential can be directly assessed from isolated HE, as the NOTCH-dependent endothelial-to-hematopoietic transition occurs on the OP9-DL4 stroma18,26,28. The definitive HE specified with this method contains erythro-myelo-lymphoid progenitors at a clonal level28, which functionally distinguishes it from our current understanding of EMP or LMPP progenitors3. As such, the presence of T-lymphoid and HBG-expressing erythroid potential, coupled with an absence of EryP-CFC potential, can be used to reliably indicate the definitive hematopoietic specification from hPSCs. Of note, solely assessing for progenitors that can give rise to HBG-expressing erythroblasts may not accurately determine the definitive potential, as, similar to that described above, the human EMP, and its signal requirements, has not been characterized to-date (reviewed in reference3).
This simple differentiation strategy is very powerful as it allows for the generation of exclusively primitive or exclusively definitive hematopoietic progenitors, enabling disease modeling comparative studies of the two programs from patient-derived iPSCs or gene-modified hPSCs. Similarly, human developmental processes can be interrogated, such as discovering what additional signal pathway(s) are required to confer self-renewal capacity, and hence HSC-like potential, from the definitive hematopoietic progenitors.
In summary, WNT manipulation during mesodermal patterning in hPSCs specifies primitive CD43+ or definitive CD34+CD45+ hematopoietic progenitors, which can be isolated and used to study hPSC-derived hematopoiesis.

Human pluripotent stem cells (hPSCs) are defined as encompassing both human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), and have the unique capability of not only undergoing self-renewal under appropriate growth conditions, but also, the capacity to differentiate into all cell types derived from the three germ layers: endoderm, mesoderm, and ectoderm1. Due to these unique abilities, hPSCs hold great promise for regenerative medicine, disease modeling, and cell-based therapies2. While multiple cell types have been successfully differentiated from hPSCs, one significant challenge is the in vitro specification of exclusively adult-like hPSC-derived hematopoietic stem cells (HSCs) and definitive hematopoietic progenitors.
One likely barrier to the development of human HSCs from hPSCs is the presence of multiple hematopoietic programs within the human embryo3. The first program which emerges, termed &#34;primitive hematopoiesis,&#34;&#160;originates within the extraembryonic yolk sac tissue and is best characterized by its transient production of erythroblast progenitors (EryP-CFC), macrophages, and megakaryocytes. Notably, this program does not give rise to HSCs, nor does it give rise to T and B lymphoid progenitors. However, the yolk sac does transiently give rise to restricted definitive hematopoietic progenitors, such as the erythro-myeloid progenitor (EMP4,5,6,7,8) and the erythroid-deficient lymphoid-primed multipotent progenitor (LMPP9). However, neither EMPs nor LMPPs are fully multipotent, or capable of HSC-like engraftment in adult recipients. In contrast, later in development, the classically defined &#34;definitive&#34; hematopoietic program is specified in the aorta-gonad-mesonephros region of the embryo proper, giving rise to all adult hematopoietic lineages, including the HSC. The specification of these intra-embryonic definitive hematopoietic cells occurs in a Notch-dependent fashion, via an endothelial-to-hematopoietic transition from hemogenic endothelium (HE)3,10,11,12,13,14. Aside from reconstitution capacity, the multilineage potential and Notch-dependence of these cells can be used to distinguish these definitive hematopoietic progenitors from the EMP and the LMPP (reviewed in references3,13).
Understanding the mechanism(s) governing primitive and definitive hematopoietic specification from hPSCs is likely critical to the reproducible production of definitive hematopoietic progenitors across a variety of hPSC lines. Until recently, hPSC differentiation protocols that could separate multipotent primitive and definitive hematopoietic progenitors did not exist15,16,17,18,19,20,21,22,23,24,25. Many approaches using fetal bovine serum (FBS) and/or stromal co-culture first outlined the hematopoietic potential of hPSC differentiation, with mixtures of primitive and definitive hematopoietic potential15,16,17,19,22,23,25. Further, many serum-free hematopoietic protocols have described the signal requirements for the specification of mesoderm from hPSCs that harbors hematopoietic potential18,20,21,24. However, as these methods still gave rise to heterogeneous mixtures of both programs, their use in clinical applications and understanding developmental mechanisms may be limited.
We have recently built on these studies, having outlined the stage-specific signal requirements for ACTIVIN/NODAL and WNT signaling in primitive and definitive hematopoietic specification from hPSC-derived mesoderm18,26. The latter was particularly unique, as its use of stage-specific WNT signal manipulation allows for the specification of either exclusively primitive or exclusively definitive hematopoietic progenitors26. During mesoderm specification, the inhibition of canonical WNT signaling with the PORCN inhibitor IWP2 results in the specification of CD43+ EryP-CFC and myeloid progenitors, with no detectable lymphoid potential. In sharp contrast, stimulation of canonical WNT signaling with the GSK3&#946; inhibitor, CHIR99021, during the same stage of differentiation resulted in the complete absence of detectable CD43+ EryP-CFC, while simultaneously leading to the specification of CD34+CD43&#8722; HE. This population possessed myeloid, HBG-expressing erythroid, and T-lymphoid potential. Subsequent analyses identified this HE as lacking the expression of CD7327,28 and CD18428, and its hematopoietic potential was NOTCH-dependent28. Further, single-cell clonal analyses demonstrated that these definitive hematopoietic lineages could be derived from multipotent single cells28. Taken together, these studies indicate that stage-specific WNT signaling manipulation can specify either pure primitive hematopoietic progenitors, or multipotent NOTCH-dependent definitive hematopoietic progenitors.
Here, we outline our differentiation strategy that yields exclusively primitive or definitive hematopoietic progenitors, via manipulation of canonical WNT signaling during mesodermal patterning, and their downstream hematopoietic lineage assays. This protocol is of great value to investigators who are interested in the production of either primitive or definitive hematopoietic progenitors from hPSCs for regenerative medicine applications.

<table>
	<tbody>
		<tr>
			<td>Iscove&#39;s Modified Dulbecco&#39;s Medium (IMD)</td>
			<td>Corning</td>
			<td>10-016</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS), ES cell rated</td>
			<td>Gemini Bioproducts</td>
			<td>100-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Hyclone</td>
			<td>SH30396.03</td>
			<td></td>
		</tr>
		<tr>
			<td>L-glutamine, 200 mM solution</td>
			<td>Life Technologies</td>
			<td>25030-081</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-streptomycin</td>
			<td>Life Technologies</td>
			<td>15070-063</td>
			<td></td>
		</tr>
		<tr>
			<td>0.25% Trypsin-EDTA</td>
			<td>Life Technologies</td>
			<td>25200056</td>
			<td></td>
		</tr>
		<tr>
			<td>0.05% Trypsin-EDTA</td>
			<td>Life Technologies</td>
			<td>25300054</td>
			<td></td>
		</tr>
		<tr>
			<td>Gelatin, porcine skin, Type A</td>
			<td>Sigma-Aldrich</td>
			<td>G1890</td>
			<td></td>
		</tr>
		<tr>
			<td>Alpha-MEM</td>
			<td>Life Technologies</td>
			<td>12000-022</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM-F12</td>
			<td>Corning</td>
			<td>10-092-CV</td>
			<td></td>
		</tr>
		<tr>
			<td>Knock-out serum replacement</td>
			<td>Life Technologies</td>
			<td>10828028</td>
			<td>&#34;KOSR&#34;</td>
		</tr>
		<tr>
			<td>Non-essential amino acids (NEAA)</td>
			<td>Life Technologies</td>
			<td>11140050</td>
			<td></td>
		</tr>
		<tr>
			<td>b-mercaptoethanol, 55 mM solution</td>
			<td>Life Technologies</td>
			<td>21985023</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid</td>
			<td>Sigma-Aldrich</td>
			<td>H1758</td>
			<td></td>
		</tr>
		<tr>
			<td>Fraction V, Bovine Serum Albumin</td>
			<td>Fisher Scientific</td>
			<td>BP1605</td>
			<td></td>
		</tr>
		<tr>
			<td>Ham&#39;s F12</td>
			<td>Corning</td>
			<td>10-080</td>
			<td></td>
		</tr>
		<tr>
			<td>N2 supplement</td>
			<td>Life Technologies</td>
			<td>17502048</td>
			<td></td>
		</tr>
		<tr>
			<td>B27 supplement, no vitamin A</td>
			<td>Life Technologies</td>
			<td>12587010</td>
			<td></td>
		</tr>
		<tr>
			<td>Stempro-34 (SP34)</td>
			<td>Life Technologies</td>
			<td>10639011</td>
			<td>&#34;SP34&#34;</td>
		</tr>
		<tr>
			<td>Growth factor reduced Matrigel</td>
			<td>Corning</td>
			<td>354230</td>
			<td>&#34;MAT&#34;</td>
		</tr>
		<tr>
			<td>L-absorbic acid</td>
			<td>Sigma-Aldrich</td>
			<td>A4403</td>
			<td></td>
		</tr>
		<tr>
			<td>Human serum transferrin</td>
			<td>Sigma-Aldrich</td>
			<td>10652202001</td>
			<td></td>
		</tr>
		<tr>
			<td>Monothioglycerol (MTG)</td>
			<td>Sigma-Aldrich</td>
			<td>M6145</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase B</td>
			<td>Roche</td>
			<td>11088831001</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase II</td>
			<td>Life Technologies</td>
			<td>17101015</td>
			<td></td>
		</tr>
		<tr>
			<td>DNaseI</td>
			<td>Calbiochem</td>
			<td>260913</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline (PBS)</td>
			<td>Life Technologies</td>
			<td>14190144</td>
			<td></td>
		</tr>
		<tr>
			<td>bFGF</td>
			<td>R&#38;D Systems</td>
			<td>233-FB</td>
			<td></td>
		</tr>
		<tr>
			<td>BMP4</td>
			<td>R&#38;D Systems</td>
			<td>314-BP</td>
			<td></td>
		</tr>
		<tr>
			<td>Activin A</td>
			<td>R&#38;D Systems</td>
			<td>338-AC</td>
			<td></td>
		</tr>
		<tr>
			<td>VEGF</td>
			<td>R&#38;D Systems</td>
			<td>293-VE</td>
			<td></td>
		</tr>
		<tr>
			<td>SCF</td>
			<td>R&#38;D Systems</td>
			<td>255-SC</td>
			<td></td>
		</tr>
		<tr>
			<td>IGF-1</td>
			<td>R&#38;D Systems</td>
			<td>291-G1</td>
			<td></td>
		</tr>
		<tr>
			<td>IL-3</td>
			<td>R&#38;D Systems</td>
			<td>203-IL</td>
			<td></td>
		</tr>
		<tr>
			<td>IL-6</td>
			<td>R&#38;D Systems</td>
			<td>206-IL</td>
			<td></td>
		</tr>
		<tr>
			<td>IL-7</td>
			<td>R&#38;D Systems</td>
			<td>207-IL</td>
			<td></td>
		</tr>
		<tr>
			<td>IL-11</td>
			<td>R&#38;D Systems</td>
			<td>218-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>TPO</td>
			<td>R&#38;D Systems</td>
			<td>288-TP</td>
			<td></td>
		</tr>
		<tr>
			<td>EPO</td>
			<td>Peprotech</td>
			<td>100-64</td>
			<td></td>
		</tr>
		<tr>
			<td>Flt-3 ligand (FLT3-L)</td>
			<td>R&#38;D Systems</td>
			<td>308-FK</td>
			<td></td>
		</tr>
		<tr>
			<td>CHIR99021</td>
			<td>Tocris</td>
			<td>4423</td>
			<td></td>
		</tr>
		<tr>
			<td>IWP2</td>
			<td>Tocris</td>
			<td>3533</td>
			<td></td>
		</tr>
		<tr>
			<td>Angiotensin II</td>
			<td>Sigma-Aldrich</td>
			<td>A9525</td>
			<td></td>
		</tr>
		<tr>
			<td>Losartan Potassium</td>
			<td>Tocris</td>
			<td>3798</td>
			<td></td>
		</tr>
		<tr>
			<td>CD4 PerCP Cy5.5 Clone RPA-T4</td>
			<td>BD Biosciences</td>
			<td>560650</td>
			<td>Dilution 1:100; T cell assay</td>
		</tr>
		<tr>
			<td>CD8 PE Clone RPA-T8</td>
			<td>BD Biosciences</td>
			<td>561950</td>
			<td>Dilution 1:10; T cell assay</td>
		</tr>
		<tr>
			<td>CD34 APC Clone 8G12</td>
			<td>BD Biosciences</td>
			<td>340441</td>
			<td>Dilution 1:100; EHT assay</td>
		</tr>
		<tr>
			<td>CD34 PE-Cy7 Clone 8G12</td>
			<td>BD Biosciences</td>
			<td>348801</td>
			<td>Dilution 1:100; Hemogenic endothelium</td>
		</tr>
		<tr>
			<td>CD43 FITC Clone 1G10</td>
			<td>BD Biosciences</td>
			<td>555475</td>
			<td>Dilution 1:10; Hemogenic endothelium</td>
		</tr>
		<tr>
			<td>CD45 APC-Cy7 Clone 2D1</td>
			<td>BD Biosciences</td>
			<td>557833</td>
			<td>Dilution 1:50; T cell assay</td>
		</tr>
		<tr>
			<td>CD45 eFluor450 Clone 2D1</td>
			<td>BD Biosciences</td>
			<td>642284</td>
			<td>Dilution 1:50; EHT assay</td>
		</tr>
		<tr>
			<td>CD56 APC Clone B159</td>
			<td>BD Biosciences</td>
			<td>555518</td>
			<td>Dilution 1:20; T cell assay</td>
		</tr>
		<tr>
			<td>CD73 PE Clone AD2</td>
			<td>BD Biosciences</td>
			<td>550257</td>
			<td>Dilution 1:50; Hemogenic endothelium</td>
		</tr>
		<tr>
			<td>CD184 APC Clone 12G5</td>
			<td>BD Biosciences</td>
			<td>555976</td>
			<td>Dilution 1:50; Hemogenic endothelium</td>
		</tr>
		<tr>
			<td>4&#39;,6-diamidino-2-phenylindole (DAPI)</td>
			<td>BD Biosciences</td>
			<td>564907</td>
			<td>Dilution 1:10,000; T cell assay</td>
		</tr>
		<tr>
			<td>OP9 DL4 cells</td>
			<td></td>
			<td></td>
			<td>Holmes, R. and J.C. Zuniga-Pflucker. Cold Spring Harb Protoc, 2009. 2009(2): p. pdb prot5156</td>
		</tr>
		<tr>
			<td>MethoCult H4034</td>
			<td>Stemcell Technologies</td>
			<td>4034</td>
			<td>&#34;MeC&#34;</td>
		</tr>
		<tr>
			<td>Milli-Q water purification system</td>
			<td>EMD Millipore</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>5% CO2 incubator</td>
			<td></td>
			<td></td>
			<td>Set at 37 C</td>
		</tr>
		<tr>
			<td>Multigas incubator</td>
			<td></td>
			<td></td>
			<td>Set at 37 C, 5% CO2, 5% O2</td>
		</tr>
		<tr>
			<td>6 well tissue culture plate</td>
			<td>Corning</td>
			<td>353046</td>
			<td></td>
		</tr>
		<tr>
			<td>24 well tissue culture plate</td>
			<td>Corning</td>
			<td>353226</td>
			<td></td>
		</tr>
		<tr>
			<td>6 well low-adherence tissue culture plate</td>
			<td>Corning</td>
			<td>3471</td>
			<td></td>
		</tr>
		<tr>
			<td>24 well low-adherence tissue culture plate</td>
			<td>Corning</td>
			<td>3473</td>
			<td></td>
		</tr>
		<tr>
			<td>35 mm tissue culture dishes</td>
			<td>Corning</td>
			<td>353001</td>
			<td></td>
		</tr>
		<tr>
			<td>Blunt-end needle, 16 gauge</td>
			<td>Corning</td>
			<td>305198</td>
			<td></td>
		</tr>
		<tr>
			<td>3 cc syringes</td>
			<td>Corning</td>
			<td>309657</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL polypropylene test tube</td>
			<td>Corning</td>
			<td>352063</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL polystyrene test tube</td>
			<td>Corning</td>
			<td>352058</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL polypropylene conical</td>
			<td>Corning</td>
			<td>430791</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL polypropylene conical</td>
			<td>Corning</td>
			<td>430921</td>
			<td></td>
		</tr>
		<tr>
			<td>2 mL serological pipette</td>
			<td>Corning</td>
			<td>357507</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL serological pipette</td>
			<td>Corning</td>
			<td>4487</td>
			<td></td>
		</tr>
		<tr>
			<td>10 mL serological pipette</td>
			<td>Corning</td>
			<td>4488</td>
			<td></td>
		</tr>
		<tr>
			<td>25 mL serological pipette</td>
			<td>Corning</td>
			<td>4489</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell scrapers</td>
			<td>Corning</td>
			<td>353085</td>
			<td></td>
		</tr>
		<tr>
			<td>2.0 mL cryovials</td>
			<td>Corning</td>
			<td>430488</td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL test tube with 40 &#181;M cell strainer</td>
			<td>Corning</td>
			<td>352235</td>
			<td></td>
		</tr>
		<tr>
			<td>40 &#181;M cell strainer</td>
			<td>Corning</td>
			<td>352340</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture centrifuge</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Biosafety hood</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>FACS AriaII or equivalent</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LSRii or equivalent</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>FlowJo software</td>
			<td>TreeStar</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td></td>
			<td></td>
			<td>Set at 37 C</td>
		</tr>
		<tr>
			<td>0.22 &#181;M filtration system</td>
			<td>Corning</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>4 C refrigerator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>-20 C Freezer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>-80 C Freezer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

directed differentiation of primitive and definitive hematopoietic progenitors from human pluripotent stem cells

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem cells (hPSCs). Until recently, efforts to differentiate hPSCs into HSCs have predominantly generated hematopoietic progenitors that lack HSC potential, and instead resemble yolk sac hematopoiesis.&#160;These resulting hematopoietic progenitors may have limited utility for in vitro disease modeling of various adult hematopoietic disorders, particularly those of the lymphoid lineages. However, we have recently described methods to generate erythro-myelo-lymphoid multilineage definitive hematopoietic progenitors from hPSCs using a stage-specific directed differentiation protocol, which we outline here. Through enzymatic dissociation of hPSCs on basement membrane matrix-coated plasticware, embryoid bodies (EBs) are formed. EBs are differentiated to mesoderm by recombinant BMP4, which is subsequently specified to the definitive hematopoietic program by the GSK3&#946; inhibitor, CHIR99021. Alternatively, primitive hematopoiesis is specified by the PORCN inhibitor, IWP2. Hematopoiesis is further driven through the addition of recombinant VEGF and supportive hematopoietic cytokines. The resulting hematopoietic progenitors generated using this method have the potential to be used for disease and developmental modeling, in vitro.

A schematic depicting the induction of primitive and definitive hematopoietic progenitors from hPSCs is illustrated in Figure 1. Mesoderm patterning by canonical WNT signaling occurs during days 2 - 3 of differentiation, followed by hematopoietic progenitor specification.
Representative flow cytometric analysis and colony forming methylcellulose assays of hPSC-derived hematopoietic differentiation cultures are shown in Figure 2. IWP2-treated differentiation cultures will yield a distinct CD34+CD43&#8722; and CD34low/&#8722;CD43+ population, while CHIR-treated differentiation cultures will have &#60;1% CD43+ cells on Day 8 of differentiation (Figure 2A,B)26. Primitive hematopoietic progenitors derived under IWP2 conditions isolated on Day 9 will give rise to predominantly primitive erythroid (EryP-CFC) and myeloid progenitors in the methylcellulose assays, while CHIR-treated cultures will be largely devoid of CFC potential at this stage (Figure 2C,F). Instead, the CD34+CD43- population derived from the CHIR99021 treatment is a heterogeneous population, containing endothelial progenitors, as well as CD34+CD43-CD73-CD184- HE (Figure 2B), which when isolated by FACS, will initially form a monolayer of endothelial-like cells (Figure 2D, left panel), that then undergoes an endothelial-to-hematopoietic transition, resulting in round, refractile non-adherent hematopoietic cells (Figure 2D, right panel). These hematopoietic cells can be assessed by flow cytometry for the expression of CD34 and CD45 (Figure 2E). Hematopoietic progenitors isolated from the EHT assays can be used in methylcellulose assays and give rise to large burst-like erythroid colony-forming units (BFU-E), small erythroid colony-forming units (CFU-E), and myeloid progenitors (CFU-M; Figure 2F).
Figure 3 depicts representative flow cytometric analyses of the T-lymphocyte assays potential from CHIR99021-derived CD34+CD43&#8722;CD73&#8722;CD184&#8722; hematopoietic progenitors (Figure 3A) and IWP2-derived (Figure 3B) CD34+CD43&#8722; hematopoietic progenitors, following 21 days of OP9-DL4 co-culture. The presence of a CD45+CD56&#8722;CD4+CD8+ population in CHIR-derived progenitors is indicative of definitive hematopoietic potential within the input CD34+ population. CD34+ and CD43+ progenitors isolated from IWP2-derived differentiations do not give rise to T-lymphocytes in this assay, under these differentiation conditions18,26.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/55196/55196fig1.jpg" /> 
Figure 1: Schematic diagram of protocol for the specification of definitive and primitive hematopoietic progenitors. Depiction of the major experimental steps and timelines of the differentiation from EBs to definitive and primitive hematopoietic progenitors. EBs are generated on Day 0 from hPSCs on MAT-coated plasticware. EBs are grown in SFD media containing BMP4 in a multi-gas incubator. On Day 1 of differentiation, cultures are fed with media supplemented with BMP4 and bFGF. On Day 2, a media change occurs with WNT manipulation through the addition of CHIR99021 (CHIR) for definitive hematopoietic progenitors and IWP2 for primitive hematopoietic progenitors. On Day 3, media is changed to SP34, supplemented with VEGF and bFGF. At Day 6, cultures are fed with media supplemented with hematopoietic cytokines. On Day 8 of the primitive hematopoietic specification, the media is changed and cells are moved to a 5% CO2 incubator for 24 h, followed by the hematopoietic progenitor cell (HPC) assay. On Day 8 of definitive hematopoietic specification, CD34+CD43-CD73-CD184- cells are isolated by FACS and assayed for definitive hemogenic endothelial potential, or T-lymphoid potential (not depicted). <a href="https://cloudflare.jove.com/files/ftp_upload/55196/55196fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/55196/55196fig2.jpg" /> 
Figure 2: Analysis of differentiation cultures and generation of primitive hematopoietic progenitors. (A) Representative flow cytometric analyses of primitive hematopoietic progenitors from IWP2-treated EBs on Day 8. (B) Representative flow cytometric analyses from CHIR99021-treated EBs on Day 8. Hemogenic endothelium (HE) can be identified and isolated as a CD34+CD43-CD73-CD184- population. (C) Colony-forming potential of day 9 hematopoietic progenitors from IWP2- and CHIR99021- (CHIR) treated differentiation cultures. n = 3, error bars represent SD of the mean, asterisks indicate statistical significance, using student&#39;s t-test *** p &#60;0.0001. (D) Representative photographs of isolated HE cells after 4 days (left) or 7+ days (right) of growth on MAT-coated plasticware. Original magnification, 100X. Scale bars = 100 &#181;m. (E) Representative flow cytometry of CD34 and CD45 expression from definitive hematopoietic progenitors after 9 days of culture. (F) Representative photograph showing morphology of EryP-CFC (left), CFU-M (middle), BFU-E and CFU-E (right). Original magnification, 40X. Scale bars = 100 &#181;m. Arrows indicate named colonies. <a href="https://cloudflare.jove.com/files/ftp_upload/55196/55196fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/55196/55196fig3.jpg" /> 
Figure 3: Analysis of definitive hematopoietic potential. Representative flow cytometric analyses of T lymphocyte potential of CHIR-derived CD34+CD43&#8722;CD73&#8722;CD184&#8722; hematopoietic progenitors (A) or IWP2-derived (B) CD34+CD43&#8722; hematopoietic progenitors, 28 days after co-culture with OP9-DL4 cells. The T-lymphocyte potential from a sample is considered positive if there are more than 100 CD45+ events detected. <a href="https://cloudflare.jove.com/files/ftp_upload/55196/55196fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>SFD Media</td>
			<td>Day 0</td>
			<td>Day 1</td>
			<td>Day 2 Definitive</td>
			<td>Day 2 Primitive</td>
		</tr>
		<tr>
			<td>BMP4</td>
			<td>10 ng/mL</td>
			<td>10 ng/mL</td>
			<td>10 ng/mL</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>bFGF</td>
			<td>&#8211;</td>
			<td>10 ng/mL</td>
			<td>5 ng/mL</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>Activin A</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>1 ng/mL</td>
		</tr>
		<tr>
			<td>CHIR99021</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>3 &#181;M</td>
			<td>&#8211;</td>
		</tr>
		<tr>
			<td>IWP2</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>3 &#181;M</td>
		</tr>
	</tbody>
</table>
Table 1: SFD-based media for Days 0-2.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>SP34 Media</td>
			<td>Day 3</td>
			<td>Day 6</td>
			<td>Day 8</td>
			<td>HE</td>
		</tr>
		<tr>
			<td>VEGF</td>
			<td>15 ng/mL</td>
			<td>15 ng/mL</td>
			<td>&#8211;</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>bFGF</td>
			<td>5 ng/mL</td>
			<td>5 ng/mL</td>
			<td>&#8211;</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>SCF</td>
			<td>&#8211;</td>
			<td>200 ng/mL</td>
			<td>100 ng/mL</td>
			<td>100 ng/mL</td>
		</tr>
		<tr>
			<td>EPO</td>
			<td>&#8211;</td>
			<td>4 IU</td>
			<td>2 IU</td>
			<td>2 IU</td>
		</tr>
		<tr>
			<td>IL-6</td>
			<td>&#8211;</td>
			<td>20 ng/mL</td>
			<td>10 ng/mL</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>IL-11</td>
			<td>&#8211;</td>
			<td>10 ng/mL</td>
			<td>5 ng/mL</td>
			<td>5 ng/mL</td>
		</tr>
		<tr>
			<td>IGF-1</td>
			<td>&#8211;</td>
			<td>50 ng/mL</td>
			<td>25 ng/mL</td>
			<td>25 ng/mL</td>
		</tr>
		<tr>
			<td>TPO</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>30 ng/mL</td>
			<td>30 ng/mL</td>
		</tr>
		<tr>
			<td>Flt-3L</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>10 ng/mL</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>IL-3</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>30 ng/mL</td>
			<td>30 ng/mL</td>
		</tr>
		<tr>
			<td>BMP4</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>10 ng/mL</td>
		</tr>
		<tr>
			<td>SHH</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>20 ng/mL</td>
		</tr>
		<tr>
			<td>Angiotensin II</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>10 &#181;g/mL</td>
		</tr>
		<tr>
			<td>Losartan potassium</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>&#8211;</td>
			<td>100 &#181;M</td>
		</tr>
	</tbody>
</table>
Table 2: SP34-based media for Days 3-8 and HE.

Watch this Scientific Journal Video about Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells at JoVE.com

Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells

Here, we present human pluripotent stem cell (hPSC) culture protocols, used to differentiate hPSCs into CD34+ hematopoietic progenitors. This method uses stage-specific manipulation of canonical WNT signaling to specify cells exclusively to either the definitive or primitive hematopoietic program.

One of the major goals for regenerative medicine is the generation and maintenance of hematopoietic stem cells (HSCs) derived from human pluripotent stem ...

directed-differentiation-primitive-definitive-hematopoietic

Nanyang Technological University

Research

JoVE Journal

Developmental Biology

10.9K Views.  Washington University in St. Louis. Here, we present human pluripotent stem cell (hPSC) culture protocols, used to differentiate hPSCs into CD34+ hematopoietic progenitors. This method uses stage-specific manipulation of canonical WNT signaling to specify cells exclusively to either the definitive or primitive hematopoietic program.

Video: Directed Differentiation of Primitive and Definitive Hematopoietic Progenitors from Human Pluripotent Stem Cells

Direct Induction of Human Neural Stem Cells from Peripheral Blood Hematopoietic Progenitor Cells

Human disease specific neuronal cultures are essential for generating in vitro models for human neurological diseases. However, the lack of access to primary human adult neural cultures raises unique challenges. Recent developments in induced pluripotent stem cells (iPSC) provides an alternative approach to derive neural cultures from skin fibroblasts through patient specific iPSC, but this process is labor intensive, requires special expertise and large amounts of resources, and can take several months. This prevents the wide application of this technology to the study of neurological diseases. To overcome some of these issues, we have developed a method to derive neural stem cells directly from human adult peripheral blood, bypassing the iPSC derivation process. Hematopoietic progenitor cells enriched from human adult peripheral blood were cultured in vitro and transfected with Sendai virus vectors containing transcriptional factors Sox2, Oct3/4, Klf4, and c-Myc. The transfection results in morphological changes in the cells which are further selected by using human neural progenitor medium containing basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF). The resulting cells are characterized by the expression for neural stem cell markers, such as nestin and SOX2. These neural stem cells could be further differentiated to neurons, astroglia and oligodendrocytes in specified differentiation media. Using easily accessible human peripheral blood samples, this method could be used to derive neural stem cells for further differentiation to neural cells for in vitro modeling of neurological disorders and may advance studies related to the pathogenesis and treatment of those diseases.

A method was developed to directly derive human neural stem cells from hematopoietic progenitor cells enriched from peripheral blood cells.

Human disease specific neuronal cultures are essential for generating in vitro models for human neurological diseases. However, the lack of access to ...

Three-dimensional Quantification of Dendritic Spines from Pyramidal Neurons Derived from Human Induced Pluripotent Stem Cells

Dendritic spines are small protrusions that correspond to the post-synaptic compartments of excitatory synapses in the central nervous system. They are distributed along the dendrites. Their morphology is largely dependent on neuronal activity, and they are dynamic. Dendritic spines express glutamatergic receptors (AMPA and NMDA receptors) on their surface and at the levels of postsynaptic densities. Each spine allows the neuron to control its state and local activity independently. Spine morphologies have been extensively studied in glutamatergic pyramidal cells of the brain cortex, using both in vivo approaches and neuronal cultures obtained from rodent tissues. Neuropathological conditions can be associated to altered spine induction and maturation, as shown in rodent cultured neurons and one-dimensional quantitative analysis 1. The present study describes a protocol for the 3D quantitative analysis of spine morphologies using human cortical neurons derived from neural stem cells (late cortical progenitors). These cells were initially obtained from induced&#160;pluripotent stem cells. This protocol allows the analysis of spine morphologies at different culture periods, and with possible comparison between induced&#160;pluripotent stem cells obtained from control individuals with those obtained from patients with psychiatric diseases.

Dendritic spines of pyramidal neurons are the sites of most excitatory synapses in mammalian brain cortex. This method describes a 3D quantitative analysis of spine morphologies in human cortical pyramidal glutamatergic neurons derived from induced&#160;pluripotent stem cells.

Dendritic spines are small protrusions that correspond to the post-synaptic compartments of excitatory synapses in the central nervous system. They are ...

Large-Scale Production of Cardiomyocytes from Human Pluripotent Stem Cells Using a Highly Reproducible Small Molecule-Based Differentiation Protocol

Maximizing the benefit of human pluripotent stem cells (hPSCs) for research, disease modeling, pharmaceutical and clinical applications requires robust methods for the large-scale production of functional cell types, including cardiomyocytes. Here we demonstrate that the temporal manipulation of WNT, TGF-&#946;, and SHH signaling pathways leads to highly efficient cardiomyocyte differentiation of single-cell passaged hPSC lines in both static suspension and stirred suspension bioreactor systems. Employing this strategy resulted in ~ 100% beating spheroids, consistently containing &#62; 80% cardiac troponin T-positive cells after 15 days of culture, validated in multiple hPSC lines. We also report on a variation of this protocol for use with cell lines not currently adapted to single-cell passaging, the success of which has been verified in 42 hPSC lines. Cardiomyocytes generated using these protocols express lineage-specific markers and show expected electrophysiological functionalities. Our protocol presents a simple, efficient and robust platform for the large-scale production of human cardiomyocytes.

Here, we present a robust, fast and scalable cardiomyocyte differentiation protocol for human pluripotent stem cells (hPSCs). Cardiomyocytes derived using this large-scale method can provide sufficient cell numbers for their effective use in human cardiovascular disease modeling, high-throughput drug screening, and potentially clinical applications.

Maximizing the benefit of human pluripotent stem cells (hPSCs) for research, disease modeling, pharmaceutical and clinical applications requires robust ...

Efficient Differentiation of Pluripotent Stem Cells to NKX6-1+ Pancreatic Progenitors

Pluripotent stem cells have the ability to self renew and differentiate to multiple lineages, making them an attractive source for the generation of pancreatic progenitor cells that can be used for the study of and future treatment of diabetes. This article outlines a four-stage differentiation protocol designed to generate pancreatic progenitor cells from human embryonic stem cells (hESCs). This protocol can be applied to a number of human pluripotent stem cell (hPSC) lines. The approach taken to generate pancreatic progenitor cells is to differentiate hESCs to accurately model key stages of pancreatic development. This begins with the induction of the definitive endoderm, which is achieved by culturing the cells in the presence of Activin A, basic Fibroblast Growth Factor (bFGF) and CHIR990210. Further differentiation and patterning with Fibroblast Growth Factor 10 (FGF10) and Dorsomorphin generates cells resembling the posterior foregut. The addition of Retinoic Acid, NOGGIN, SANT-1 and FGF10 differentiates posterior foregut cells into cells characteristic of pancreatic endoderm. Finally, the combination of Epidermal Growth Factor (EGF), Nicotinamide and NOGGIN leads to the efficient generation of PDX1+/NKX6-1+ cells. Flow cytometry is performed to confirm the expression of specific markers at key stages of pancreatic development. The PDX1+/NKX6-1+ pancreatic progenitors at the end of stage 4 are capable of generating mature &#946; cells upon transplantation into immunodeficient mice and can be further differentiated to generate insulin-producing cells in vitro. Thus, the efficient generation of PDX1+/NKX6-1+ pancreatic progenitors, as demonstrated in this protocol, is of great importance as it provides a platform to study human pancreatic development in vitro and provides a source of cells with the potential of differentiating to &#946; cells that could eventually be used for the treatment of diabetes.

Efficient Differentiation of Pluripotent Stem Cells to NKX6-1+ Pancreatic Progenitors

Here we describe a 4-stage protocol to differentiate human embryonic stem cells to NKX6-1+ pancreatic progenitors in vitro. This protocol can be applied to a variety of human pluripotent stem cell lines.

Pluripotent stem cells have the ability to self renew and differentiate to multiple lineages, making them an attractive source for the generation of ...

In Vitro Differentiation of Human Pluripotent Stem Cells into Trophoblastic Cells

The placenta is the first organ to develop during embryogenesis and is required for the survival of the developing embryo. The placenta is comprised of various trophoblastic cells that differentiate from the extra-embryonic trophectoderm cells of the preimplantation blastocyst. As such, our understanding of the early differentiation events of the human placenta is limited because of ethical and legal restrictions on the isolation and manipulation of human embryogenesis. Human pluripotent stem cells (hPSCs) are a robust model system for investigating human development and can also be differentiated in vitro into trophoblastic cells that express markers of the various trophoblast cell types. Here, we present a detailed protocol for differentiating hPSCs into trophoblastic cells using bone morphogenic protein 4 and inhibitors of the Activin/Nodal signaling pathways. This protocol generates various trophoblast cell types that can be transfected with siRNAs for investigating loss-of-function phenotypes or can be infected with pathogens. Additionally, hPSCs can be genetically modified and then differentiated into trophoblast progenitors for gain-of-function analyses. This in vitro differentiation method for generating human trophoblasts starting from hPSCs overcomes the ethical and legal restrictions of working with early human embryos, and this system can be used for a variety of applications, including drug discovery and stem cell research.

In Vitro Differentiation of Human Pluripotent Stem Cells into Trophoblastic Cells

Here, we present a protocol to efficiently generate human trophoblastic cells from human pluripotent stem cells using bone morphogenic protein 4 and inhibitors of the Activin/Nodal pathways. This method is suitable for the efficient differentiation of human pluripotent stem cells and can generate large quantities of cells for genetic manipulation.

The placenta is the first organ to develop during embryogenesis and is required for the survival of the developing embryo. The placenta is comprised of ...

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 ...

Generation of First Heart Field-like Cardiac Progenitors and Ventricular-like Cardiomyocytes from Human Pluripotent Stem Cells

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is a pre-requisite for cell-based cardiac therapies and disease modeling. We have recently shown that Id genes are both necessary and sufficient to specify first heart field progenitors during vertebrate development. This differentiation protocol leverages these findings and uses Id1 overexpression in combination with Activin A as potent specifying cues to produce first heart field-like (FHF-L) progenitors. Importantly, resulting progenitors efficiently differentiate (~70&#8211;90%) into ventricular-like cardiomyocytes. Here we describe a detailed method to 1) generate Id1-overexpressing hPSCs and 2) differentiate scalable quantities of cryopreservable FHF-L progenitors and ventricular-like cardiomyocytes.

Here we describe a scalable method, using a simple combination of Activin A and lentivirus-mediated Id1-overexpression, to generate first heart field-like cardiac progenitors and ventricular-like cardiomyocytes from human pluripotent stem cells.

The generation of large amounts of functional human pluripotent stem cells-derived cardiac progenitors and cardiomyocytes of defined heart field origin is ...

Efficient and Scalable Directed Differentiation of Clinically Compatible Corneal Limbal Epithelial Stem Cells from Human Pluripotent Stem Cells

Corneal limbal epithelial stem cells (LESCs) are responsible for continuously renewing the corneal epithelium, and thus maintaining corneal homeostasis and visual clarity. Human pluripotent stem cell (hPSC)-derived LESCs provide a promising cell source for corneal cell replacement therapy. Undefined, xenogeneic culture and differentiation conditions cause variation in research results and impede the clinical translation of hPSC-derived therapeutics. This protocol provides a reproducible and efficient method for hPSC-LESC differentiation under xeno- and feeder cell-free conditions. Firstly, monolayer culture of undifferentiated hPSC on recombinant laminin-521 (LN-521) and defined hPSC medium serves as a foundation for robust production of high-quality starting material for differentiations. Secondly, a rapid and simple hPSC-LESC differentiation method yields LESC populations in only 24 days. This method includes a four-day surface ectodermal induction in suspension with small molecules, followed by adherent culture phase on LN-521/collagen IV combination matrix in defined corneal epithelial differentiation medium. Cryostoring and extended differentiation further purifies the cell population and enables banking of the cells in large quantities for cell therapy products. The resulting high-quality hPSC-LESCs provide a potential novel treatment strategy for corneal surface reconstruction to treat limbal stem cell deficiency (LSCD).

This protocol introduces a simple two-step method for differentiating corneal limbal epithelial stem cells from human pluripotent stem cells under xeno- and feeder cell-free culture conditions. The cell culture methods presented here enable cost-efficient, large-scale production of clinical quality cells applicable to corneal cell therapy use.

Corneal limbal epithelial stem cells (LESCs) are responsible for continuously renewing the corneal epithelium, and thus maintaining corneal homeostasis ...

Efficient Differentiation of Human Pluripotent Stem Cells into Liver Cells

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver failure&#8212;which can be caused by chronic alcohol intake, hepatitis, acute poisoning, or other insults&#8212;is a severe condition that can culminate in bleeding, jaundice, coma, and eventually death. However, approaches to treat liver failure, as well as studies of liver function and disease, have been stymied in part by the lack of a plentiful supply of human liver cells. To this end, this protocol details the efficient differentiation of human pluripotent stem cells (hPSCs) into hepatocyte-like cells, guided by a developmental roadmap that describes how liver fate is specified across six consecutive differentiation steps. By manipulating developmental signaling pathways to promote liver differentiation and to explicitly suppress the formation of unwanted cell fates, this method efficiently generates populations of human liver bud progenitors and hepatocyte-like cells by days 6 and 18 of PSC differentiation, respectively. This is achieved through the temporally-precise control of developmental signaling pathways, exerted by small molecules and growth factors in a serum-free culture medium. Differentiation in this system occurs in monolayers and yields hepatocyte-like cells that express characteristic hepatocyte enzymes and have the ability to engraft a mouse model of chronic liver failure. The ability to efficiently generate large numbers of human liver cells in vitro has ramifications for treatment of liver failure, for drug screening, and for mechanistic studies of liver disease.

This protocol details a monolayer, serum-free method to efficiently generate hepatocyte-like cells from human pluripotent stem cells (hPSCs) in 18 days. This entails six steps as hPSCs sequentially differentiate into intermediate cell-types such as the primitive streak, definitive endoderm, posterior foregut and liver bud progenitors before forming hepatocyte-like cells.

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver ...

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 ...