This work was supported by grants from NIH/NEI (R01EY023962), NIH/NICHD (R01HD082098), RPB Stein Innovation Award, The Maryland Stem Cell Research Fund (2018-MSCRFV-4048, 2014-MSCRFE-0742), Novo Nordisk Science Forum Award, and The Moseley Foundation.

<ol>
	<li>Ying, Q. 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=The+ground+state+of+embryonic+stem+cell+self-renewal.">The ground state of embryonic stem cell self-renewal.</a> Nature. 453 (7194), 519-523 (2008).</li><li>Zimmerlin, L., Park, T. S., Zambidis, E. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capturing+Human+Naive+Pluripotency+in+the+Embryo+and+in+the+Dish.">Capturing Human Naive Pluripotency in the Embryo and in the Dish.</a> Stem Cells Dev. 26 (16), 1141-1161 (2017).</li><li>Zimmerlin, 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=Tankyrase+inhibition+promotes+a+stable+human+naive+pluripotent+state+with+improved+functionality.">Tankyrase inhibition promotes a stable human naive pluripotent state with improved functionality.</a> Development. 143 (23), 4368-4380 (2016).</li><li>Jozefczuk, J., Drews, K., Adjaye, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+mouse+embryonic+fibroblast+cells+suitable+for+culturing+human+embryonic+and+induced+pluripotent+stem+cells.">Preparation of mouse embryonic fibroblast cells suitable for culturing human embryonic and induced pluripotent stem cells.</a> J Vis Exp. (64), e3854 (2012).</li><li>Chen, G., 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=Chemically+defined+conditions+for+human+iPSC+derivation+and+culture.">Chemically defined conditions for human iPSC derivation and culture.</a> Nat Methods. 8 (5), 424-429 (2011).</li><li>Ludwig, T. 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+human+embryonic+stem+cells+in+defined+conditions.">Derivation of human embryonic stem cells in defined conditions.</a> Nat Biotechnol. 24 (2), 185-187 (2006).</li><li>Howe, B., Umrigar, A., Tsien, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromosome+preparation+from+cultured+cells.">Chromosome preparation from cultured cells.</a> J Vis Exp. (83), e50203 (2014).</li><li>Burridge, P. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+universal+system+for+highly+efficient+cardiac+differentiation+of+human+induced+pluripotent+stem+cells+that+eliminates+interline+variability.">A universal system for highly efficient cardiac differentiation of human induced pluripotent stem cells that eliminates interline variability.</a> PLoS One. 6 (4), 18293 (2011).</li><li>Park, T. 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=Growth+factor-activated+stem+cell+circuits+and+stromal+signals+cooperatively+accelerate+non-integrated+iPSC+reprogramming+of+human+myeloid+progenitors.">Growth factor-activated stem cell circuits and stromal signals cooperatively accelerate non-integrated iPSC reprogramming of human myeloid progenitors.</a> PLoS One. 7 (8), 42838 (2012).</li><li>Watanabe, 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=A+ROCK+inhibitor+permits+survival+of+dissociated+human+embryonic+stem+cells.">A ROCK inhibitor permits survival of dissociated human embryonic stem cells.</a> Nat Biotechnol. 25 (6), 681-686 (2007).</li><li>Li, X., Krawetz, R., Liu, S., Meng, G., Rancourt, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ROCK+inhibitor+improves+survival+of+cryopreserved+serum/feeder-free+single+human+embryonic+stem+cells.">ROCK inhibitor improves survival of cryopreserved serum/feeder-free single human embryonic stem cells.</a> Hum Reprod. 24 (3), 580-589 (2009).</li><li>Collier, 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=Comprehensive+Cell+Surface+Protein+Profiling+Identifies+Specific+Markers+of+Human+Naive+and+Primed+Pluripotent+States.">Comprehensive Cell Surface Protein Profiling Identifies Specific Markers of Human Naive and Primed Pluripotent States.</a> Cell Stem Cell. 20 (6), 874-890 (2017).</li><li>Liu, X., 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=Comprehensive+characterization+of+distinct+states+of+human+naive+pluripotency+generated+by+reprogramming.">Comprehensive characterization of distinct states of human naive pluripotency generated by reprogramming.</a> Nat Methods. 14 (11), 1055-1062 (2017).</li><li>Choi, 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=Prolonged+Mek1/2+suppression+impairs+the+developmental+potential+of+embryonic+stem+cells.">Prolonged Mek1/2 suppression impairs the developmental potential of embryonic stem cells.</a> Nature. 548 (7666), 219-223 (2017).</li><li>Yang, Y., 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+Pluripotent+Stem+Cells+with+In+Vivo+Embryonic+and+Extraembryonic+Potency.">Derivation of Pluripotent Stem Cells with In Vivo Embryonic and Extraembryonic Potency.</a> Cell. 169 (2), 243-257 (2017).</li><li>Orlova, V. 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=Generation,+expansion+and+functional+analysis+of+endothelial+cells+and+pericytes+derived+from+human+pluripotent+stem+cells.">Generation, expansion and functional analysis of endothelial cells and pericytes derived from human pluripotent stem cells.</a> Nat Protoc. 9 (6), 1514-1531 (2014).</li><li>Park, T. S., Zimmerlin, L., Zambidis, E. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+and+simultaneous+generation+of+hematopoietic+and+vascular+progenitors+from+human+induced+pluripotent+stem+cells.">Efficient and simultaneous generation of hematopoietic and vascular progenitors from human induced pluripotent stem cells.</a> Cytometry A. 83 (1), 114-126 (2013).</li><li>Park, T. 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=Vascular+progenitors+from+cord+blood-derived+induced+pluripotent+stem+cells+possess+augmented+capacity+for+regenerating+ischemic+retinal+vasculature.">Vascular progenitors from cord blood-derived induced pluripotent stem cells possess augmented capacity for regenerating ischemic retinal vasculature.</a> Circulation. 129 (3), 359-372 (2014).</li><li>Taapken, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Karotypic+abnormalities+in+human+induced+pluripotent+stem+cells+and+embryonic+stem+cells.">Karotypic abnormalities in human induced pluripotent stem cells and embryonic stem cells.</a> Nat Biotechnol. 29 (4), 313-314 (2011).</li><li>Mitalipova, M. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preserving+the+genetic+integrity+of+human+embryonic+stem+cells.">Preserving the genetic integrity of human embryonic stem cells.</a> Nat Biotechnol. 23 (1), 19-20 (2005).</li><li>Beers, 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=Passaging+and+colony+expansion+of+human+pluripotent+stem+cells+by+enzyme-free+dissociation+in+chemically+defined+culture+conditions.">Passaging and colony expansion of human pluripotent stem cells by enzyme-free dissociation in chemically defined culture conditions.</a> Nat Protoc. 7 (11), 2029-2040 (2012).</li><li>Laurent, L. 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=Dynamic+changes+in+the+copy+number+of+pluripotency+and+cell+proliferation+genes+in+human+ESCs+and+iPSCs+during+reprogramming+and+time+in+culture.">Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture.</a> Cell Stem Cell. 8 (1), 106-118 (2011).</li><li>Hussein, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Copy+number+variation+and+selection+during+reprogramming+to+pluripotency.">Copy number variation and selection during reprogramming to pluripotency.</a> Nature. 471 (7336), 58-62 (2011).</li></ol>

Under a licensing agreement between Life Technologies and the Johns Hopkins University (JHU), Dr. Zambidis is entitled to a share of royalty received by the University for licensing of stem cells. The terms of this arrangement are managed by JHU in accordance with its Conflict of Interest policies. This does not alter authors' adherence to journal policies on sharing data and materials.

The LIF-3i system applies a modified version of the classic murine 2i na&#239;ve reversion cocktail1 to human pluripotent stem cells. The self-renewal of hPSC (which cannot expand in 2i alone) is stabilized in LIF-2i by supplementing this cocktail with the tankyrase inhibitor XAV939. LIF-3i culture allows bulk and efficient reversion of the conventional hPSC to a pluripotent state resembling the human preimplantation epiblast3. Although the...

The 2i (MEK/ERK and GSK3&#946; inhibitor) culture system was originally developed to refine heterogeneous serum-based mouse embryonic stem cells (mESC) cultures to a uniform ground state of pluripotency akin to the mouse preimplantation epiblast1. However, 2i does not support the stable maintenance of human pluripotent stem cell (hPSC) lines2. The various complex small molecule, growth factor-supplemented, and transgenic approaches have recently been reported to capture putatively similar human na&#239;ve-like pluripotent molecular states2. However, many of the &#34;na&#239;ve-like&#34; states created with these methods also exhibited karyotypic instability, epigenomic defects (e.g., global loss of parental genomic imprinting), or impaired differentiation potential.
In contrast, the cocktail of triple chemical inhibition of GSK3&#946;, ERK and tankyrase signaling and leukemia inhibitory factor (LIF-3i) was sufficient for the stable na&#239;ve-like reversion of a broad repertoire of conventional hPSC lines3. LIF-3i-reverted na&#239;ve hPSC (N-hPSC) maintained normal karyotypes and increased their expressions of na&#239;ve-specific human preimplantation epiblast genes (e.g.,NANOG, KLF2, NR5A2, DNMT3L, HERVH, Stella (DPPA3), KLF17, TFCP2L1). LIF-3i reversion also conferred hPSC with an array of molecular and biochemical characteristics unique to mESC-like na&#239;ve pluripotency that included increased phosphorylated STAT3 signaling, decreased ERK phosphorylation, global 5-methylcytosine CpG hypomethylation, genome-wide CpG demethylation at embryonic stem cell (ESC)-specific gene promoters, and dominant distal OCT4 enhancer usage. Moreover, in comparison to other na&#239;ve reversion methods that resulted in aberrantly hypomethylated imprinted genomic loci, LIF-3i-reverted N-hPSC were devoid of systematic loss of imprinted CpG patterns or loss of DNA methyltransferase expression (e.g., DNMT1, DNMT3A, DNMT3B)3.
A direct LIF-3i culture of a broad array of conventional human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC) grown on either feeders or E8 feeder-free conditions achieved rapid and bulk reversion to a na&#239;ve epiblast-like state. However, direct LIF-3i na&#239;ve reversion may be inefficient in some unstable conventional hPSC lines due to the inherent genomic and lineage-primed variabilities arising from the genetically diverse donor backgrounds.
Thus, to broaden the utility of the LIF-3i method, a stepwise optimization was developed and is presented herein, that allows universal na&#239;ve reversion with almost any conventional hESC or transgene-free hiPSC line cultured on feeders. This universalized na&#239;ve reversion method employs a transient initial culture step in conventional hPSC that supplements the LIF-3i cocktail with two additional small molecules (LIF-5i) that potentiate protein kinase A (forskolin) and sonic hedgehog (sHH) (purmorphamine) signaling. One initial passage of conventional hPSC in LIF-5i adapts them to subsequent stable LIF-3i reversion in bulk quantities. Initial LIF-5i adaptation significantly augments the initial single cell clonal proliferation of conventional hPSC grown on E8 or feeders (prior to their subsequent stable, continuous passage in LIF-3i alone). Conventional hPSC lines adapted first to one passage in LIF-5i tolerate subsequent bulk clonal passaging of na&#239;ve-reverted cells in LIF-3i conditions, which obviates the need for picking and subcloning of the rare stable colonies, or the routine use of anti-apoptotic molecules or Rho-associated protein kinase (ROCK) inhibitors.
The LIF-3i method has been successfully employed to stably expand and maintain a broad repertoire of &#62;30 independent, genetically-diverse conventional hPSC lines for &#62;10&#8211;30 passages using either non-enzymatic or enzymatic dissociation methods, and without evidence of induction of chromosomal or epigenomic abnormalities, including abnormalities at imprinted gene loci. Additionally, sequential LIF-5i/LIF-3i culture is the only na&#239;ve reversion method that has thus far been reported that improves the functional pluripotency of a broad repertoire of conventional hPSC lines by decreasing their lineage-primed gene expression and dramatically improving their multipotent differentiation potency. The LIF-3i na&#239;ve reversion method erases the inherent interline variability of differentiation of lineage-primed, conventional hPSC lines, and will have a great utility of application in regenerative medicine and cellular therapies.

<table><tbody><tr><td>anti- SSEA-1/CD15 antibody, APC conjugated</td><td>BD Biosciences</td><td>561716</td><td>use 5&amp;micro;L per assay (FACS)</td></tr><tr><td>anti- TFCP2L1 antibody</td><td>Sigma Aldrich</td><td>HPA029708</td><td>use at a 1:100 dilution (immunostainings)</td></tr><tr><td>anti-beta-Actin antibody</td><td>Abcam</td><td>ab6276</td><td>use at 1:5000 (Western blot)</td></tr><tr><td>anti-CD146 antibody,&amp;nbsp; PE conjugated&amp;nbsp;</td><td>BD Biosciences</td><td>550315</td><td>use 5&amp;micro;L per assay (FACS)</td></tr><tr><td>anti-CD31 antibody, APC conjugated</td><td>eBioscience</td><td>17-0319-42</td><td>use 2&amp;micro;L per assay (FACS)</td></tr><tr><td>anti-CD31 microbead kit</td><td>Miltenyi Biotec</td><td>130-091-935</td><td></td></tr><tr><td>anti-NANOG antibody</td><td>Abcam</td><td>ab109250</td><td>use at a 1:100 dilution (immunostainings)</td></tr><tr><td>anti-NR5A2 antibody</td><td>Sigma Aldrich</td><td>HPA005455</td><td>use at a 1:100 dilution (immunostainings)</td></tr><tr><td>anti-p44/42 MAPK (Erk1/2) antibody</td><td>Cell Signaling</td><td>4695</td><td>use at 1:1000 (Western blot), for detection of total protein</td></tr><tr><td>anti-phospho-p44/42 MAPK (Erk1/2) (Thr202/Tyr204 antibody</td><td>Cell Signaling</td><td>4370</td><td>use at 1:1000 (Western blot)</td></tr><tr><td>anti-phospho-STAT3 (Tyr705) antibody</td><td>Cell Signaling</td><td>9145</td><td>use at 1:1000 (Western blot)</td></tr><tr><td>anti-rabbit immunoglobulin antibody, biotinylated</td><td>Agilent</td><td>E0432</td><td>use at a 1:500-1:1000 dilution (immunostainings)</td></tr><tr><td>anti-SSEA-4 antibody, APC conjugated&amp;nbsp;</td><td>R&amp;amp;D System</td><td>FAB1435A</td><td>use 5&amp;micro;L per assay (FACS)</td></tr><tr><td>anti-SSEA-4 GloLIVE antibody, NL493 conjugated</td><td>R&amp;amp;D System</td><td>NLLC1435G</td><td>use at 1:50 dilution (live and fixed immunostainings)</td></tr><tr><td>anti-STAT3 antibody</td><td>Cell Signaling</td><td>9139</td><td>use at 1:1000 (Western blot), for detection of total protein</td></tr><tr><td>anti-STELLA/DPPA3 antibody</td><td>Millipore</td><td>MAB4388</td><td>use at a 1:50 dilution (immunostainings)</td></tr><tr><td>anti-TRA-1-60 GloLIVE antibody, NL557 conjugated&amp;nbsp;</td><td>R&amp;amp;D System</td><td>NLLC4770R</td><td>use at&amp;nbsp; a 1:50 dilution (live and fixed immunostainings)</td></tr><tr><td>anti-TRA-1-60 StainAlive Antibody, DyLight 488 conjugated</td><td>Stemgent</td><td>09-0068</td><td>use at a 1:100 dilution (live and fixed immunostainings)</td></tr><tr><td>anti-TRA-1-81 StainAlive Antibody, DyLight 488 conjugated</td><td>Stemgent</td><td>09-0069</td><td>use at a 1:100 dilution (live and fixed immunostainings)</td></tr><tr><td>anti-TRA1-60 antibody, PE conjugated</td><td>BD Biosciences</td><td>560193</td><td>use 10&amp;micro;L per assay (FACS)</td></tr><tr><td>anti-TRA1-81 antibody, PE conjugated</td><td>BD Biosciences</td><td>560161</td><td>use 10&amp;micro;L per assay (FACS)</td></tr><tr><td>APEL2-Li</td><td>StemCell Technologies</td><td>5271</td><td></td></tr><tr><td>Bovine Serum Albumin</td><td>Sigma Aldrich</td><td>A3311</td><td></td></tr><tr><td>CellAdhere dilution buffer</td><td>StemCell Technologies</td><td>7183</td><td>dilutent for Vitronectin XF&amp;trade; matrix</td></tr><tr><td>CF1 mouse</td><td>Charles river</td><td>023</td><td></td></tr><tr><td>CHIR99021</td><td>R&amp;amp;D System</td><td>L5283</td><td>reconstitute at 100mM in DMSO</td></tr><tr><td>confocal microscope system</td><td>Zeiss</td><td>LSM 510</td><td></td></tr><tr><td>cord blood CD34+ derived iPSC line</td><td>Thermo Fisher Scientific</td><td>A18945</td><td>also referred as 6.2 line</td></tr><tr><td>Corning Costar tissue culture-treated 6-well plates</td><td>Corning</td><td>3506</td><td></td></tr><tr><td>Countess&amp;nbsp; cell counting chamber slide</td><td>Thermo Fisher Scientific</td><td>C10228</td><td></td></tr><tr><td>Countess automated cell counter</td><td>Thermo Fisher Scientific</td><td>AMQAX1000</td><td></td></tr><tr><td>DMEM (Dulbecco&#039;s Modified Eagle Medium)&amp;nbsp;</td><td>Thermo Fisher Scientific</td><td>11995-065</td><td></td></tr><tr><td>DMEM-F12</td><td>Thermo Fisher Scientific</td><td>11330-032</td><td></td></tr><tr><td>DMSO (dimethyl sulfoxide)</td><td>Sigma Aldrich</td><td>D2650</td><td></td></tr><tr><td>DR4 mouse</td><td>The Jackson Laboratory</td><td>3208</td><td></td></tr><tr><td>Essential 8 (E8) medium</td><td>StemCell Technologies</td><td>5940</td><td></td></tr><tr><td>Fetal bovin serum (FBS)</td><td>Thermo Fisher Scientific</td><td>SH30071.03</td><td></td></tr><tr><td>Forskolin</td><td>Stemgent</td><td>04-0025</td><td>reconstitute at 100mM in DMSO</td></tr><tr><td>Gelatin (porcine)</td><td>Sigma Aldrich</td><td>G1890-100G</td><td>resuspend in water and sterilize with an autoclave</td></tr><tr><td>KnockOut Serum Replacement</td><td>Thermo Fisher Scientific</td><td>10828-028</td><td></td></tr><tr><td>L-Glutamine (100X)</td><td>Thermo Fisher Scientific</td><td>25030-081</td><td></td></tr><tr><td>MEM Non-essential amino acid (MEM NEAA) (100X)</td><td>Thermo Fisher Scientific</td><td>11140-050</td><td></td></tr><tr><td>mTeSR1 medium</td><td>StemCell Technologies</td><td>85850</td><td></td></tr><tr><td>Nalgene cryogenic vials</td><td>Thermo Fisher Scientific</td><td>5000-0020</td><td></td></tr><tr><td>Nunc Lab-Tek II Chamber Slide System</td><td>Fisher Scientific</td><td>154534</td><td></td></tr><tr><td>Paraformaldehyde (PFA) solution , 4% in PBS</td><td>USB Corporation&amp;nbsp;</td><td>19943</td><td></td></tr><tr><td>PD0325901</td><td>Sigma Aldrich</td><td>PZ0162</td><td>reconstitute at 100mM in DMSO</td></tr><tr><td>Penicillin/streptomycin (10,000 U/mL)</td><td>Thermo Fisher Scientific</td><td>15140-122</td><td></td></tr><tr><td>Phosphate buffered saline (PBS)</td><td>Biological Industries</td><td>02-023-1A</td><td></td></tr><tr><td>Purmorphamine</td><td>Stemgent</td><td>04-0009</td><td>reconstitute at 10mM in DMSO</td></tr><tr><td>recombinant human Activin A</td><td>Peprotech</td><td>AF-120-14E</td><td></td></tr><tr><td>recombinant human Bone morphogenetic protein (BMP)-4</td><td>Peprotech</td><td>120-05ET</td><td>resupend at 100ug/mL in 0.1% bovine serum albumin in PBS</td></tr><tr><td>recombinant human FGF-basic (bFGF)</td><td>Peprotech</td><td>100-18B</td><td>resupend at 100ug/mL in 0.1% bovine serum albumin in PBS</td></tr><tr><td>recombinant human LIF</td><td>Peprotech</td><td>300-05</td><td>resupend at 100ug/mL in 0.1% bovine serum albumin in PBS</td></tr><tr><td>SB431542&amp;nbsp;</td><td>Stemgent</td><td>04-0010-05</td><td>reconstitute at 100mM in DMSO</td></tr><tr><td>Stemolecule Y27632 in Solution</td><td>Stemgent</td><td>04-0012-02</td><td>ROCK inhibitor in solution (10mM)</td></tr><tr><td>StemPro Accutase Cell Dissociation Reagent</td><td>Thermo Fisher Scientific</td><td>A11105-01</td><td></td></tr><tr><td>Streptavidin-Cy3 conjugate</td><td>Sigma Aldrich</td><td>S6402</td><td>use at 1:500-1:1000 dilution (immunostainings)</td></tr><tr><td>Thermo Scientific Mr. Frosty Freezing Container</td><td>Thermo Fisher Scientific</td><td>5100-0001</td><td></td></tr><tr><td>Vascular endothelial growth factor (VEGF)-165</td><td>Peprotech</td><td>100-21</td><td>resupend at 100ug/mL in 0.1% bovine serum albumin in PBS</td></tr><tr><td>Vitronectin XF matrix</td><td>StemCell Technologies</td><td>7180</td><td>dilute at 40&amp;micro;L/mL in CellAdhere&amp;trade; dilution buffer</td></tr><tr><td>XAV939</td><td>Sigma Aldrich</td><td>X3004</td><td>reconstitute at 100mM in DMSO</td></tr><tr><td>&amp;beta;-mercaptoethanol</td><td>Thermo Fisher Scientific</td><td>21985-023</td><td>light sensitive</td></tr></tbody></table>

chemical reversion of conventional human pluripotent stem cells to a na&#239;ve-like state with improved multilineage differentiation potency

Na&#239;ve human pluripotent stem cells (N-hPSC) with improved functionality may have a wide impact in regenerative medicine. The goal of this protocol is to efficiently revert lineage-primed, conventional human pluripotent stem cells (hPSC) maintained on either feeder-free or feeder-dependent conditions to a na&#239;ve-like pluripotency with improved functionality. This chemical na&#239;ve reversion method employs the classical leukemia inhibitory factor (LIF), GSK3&#946;, and MEK/ERK inhibition cocktail (LIF-2i), supplemented with only a tankyrase inhibitor XAV939 (LIF-3i). LIF-3i reverts conventional hPSC to a stable pluripotent state adopting biochemical, transcriptional, and epigenetic features of the human pre-implantation epiblast. This LIF-3i method requires minimal cell culture manipulation and is highly reproducible in a broad repertoire of human embryonic stem cell (hESC) and transgene-free human induced pluripotent stem cell (hiPSC) lines. The LIF-3i method does not require a re-priming step prior to the differentiation; N-hPSC can be differentiated directly with extremely high efficiencies and maintain karyotypic and epigenomic stabilities (including at imprinted loci). To increase the universality of the method, conventional hPSC are first cultured in the LIF-3i cocktail supplemented with two additional small molecules that potentiate protein kinase A (forskolin) and sonic hedgehog (sHH) (purmorphamine) signaling (LIF-5i). This brief LIF-5i adaptation step significantly enhances the initial clonal expansion of conventional hPSC and permits them to be subsequently na&#239;ve-reverted with LIF-3i alone in bulk quantities, thus obviating the need for picking/subcloning rare N-hPSC colonies later. LIF-5i-stabilized hPSCs are subsequently maintained in LIF-3i alone without the need of anti-apoptotic molecules. Most importantly, LIF-3i reversion markedly improves the functional pluripotency of a broad repertoire of conventional hPSC by decreasing their lineage-primed gene expression and erasing the interline variability of directed differentiation commonly observed amongst independent hPSC lines. Representative characterizations of LIF-3i-reverted N-hPSC are provided, and experimental strategies for functional comparisons of isogenic hPSC in lineage-primed vs. na&#239;ve-like states are outlined.

This protocol optimizes efficient na&#239;ve-like reversion with LIF-3i in both feeder-dependent and feeder-independent lineage-primed conventional hPSC cultures (Figure 1). The detailed protocol, described herein, outlines sequential adaptation to LIF-3i starting from either feeder-dependent or feeder-free conventional hPSC conditions (e.g. E8 medium).
Representative results for the LIF-3i...

Watch this Scientific Journal Video about Chemical Reversion of Conventional Human Pluripotent Stem Cells to a NaÃ¯ve-like State with Improved Multilineage Differentiation Potency at JoVE.com

Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Na&#239;ve-like State with Improved Multilineage Differentiation Potency

We present a protocol for efficient, bulk, and rapid chemical reversion of conventional lineage-primed human pluripotent stem cells (hPSC) into an epigenomically-stable na&#239;ve preimplantation epiblast-like pluripotent state. This method results in decreased lineage-primed gene expression and marked improvement in directed multilineage differentiation across a broad repertoire of conventional hPSC lines.

Na&#239;ve human pluripotent stem cells (N-hPSC) with improved functionality may have a wide impact in regenerative medicine. The goal of this protocol is ...

chemical-reversion-conventional-human-pluripotent-stem-cells-to-nave

Research

JoVE Journal

Developmental Biology

9.9K Views.  Johns Hopkins School of Medicine. Presenteren we een protocol voor snelle, efficiënte en bulk chemische terugkeer van conventionele lineage-primer menselijke pluripotente stamcellen (hPSC) in een epigenomically-stable naïef voor inplanting epiblast-achtige pluripotente staat. Deze methode resulteert in verminderde lineage-primer genexpressie en duidelijke verbetering gestuurde multilineage differentiatie over een breed repertoire van conventionele hPSC lijnen.

Video: Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Naïve-like State with Improved Multilineage Differentiation Potency

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Neuroscience

Reprogramming Primary Amniotic Fluid and Membrane Cells to Pluripotency in Xeno-free Conditions

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic fluid and membrane mesenchymal stem cells, represent a unique type of undifferentiated cells with promise in tissue engineering and for reprogramming into iPSC for future pediatric interventions and stem cell banking. The protocol presented here describes an optimized procedure for extracting and culturing primary amniotic fluid and membrane mesenchymal stem cells and generating episomal induced pluripotent stem cells from these cells in fully chemically defined culture conditions utilizing human recombinant vitronectin and the E8 medium. Characterization of the new lines by applying stringent methods &#8211; flow cytometry, confocal imaging, teratoma formation and transcriptional profiling &#8211; is also described. The newly generated lines express markers of embryonic stem cells &#8211; Oct3/4A, Nanog, Sox2, TRA-1-60, TRA-1-81, SSEA-4 &#8211; while being negative for the SSEA-1 marker. The stem cell lines form teratomas in scid-beige mice in 6-8 weeks and the teratomas contain tissues representative of all three germ layers. Transcriptional profiling of the lines by submitting global expression microarray data to a bioinformatic pluripotency assessment algorithm deemed all lines pluripotent and therefore, this approach is an attractive alternative to animal testing. The new iPSC lines can readily be used in downstream experiments involving the optimization of differentiation and tissue engineering.

This protocol describes the reprogramming of primary amniotic fluid and membrane mesenchymal stem cells into induced pluripotent stem cells using a non-integrating episomal approach in fully chemically defined conditions. Procedures of extraction, culture, reprogramming, and characterization of the resulting induced pluripotent stem cells by stringent methods are detailed.

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic ...

Transient Treatment of Human Pluripotent Stem Cells with DMSO to Promote Differentiation

Despite the growing use of pluripotent stem cells (PSCs), challenges in efficiently differentiating embryonic and induced pluripotent stem cells (ESCs and iPSCs) across various lineages remain. Numerous differentiation protocols have been developed, yet variability across cell lines and low rates of differentiation impart challenges in successfully implementing these protocols. Described here is an easy and inexpensive means to enhance the differentiation capacity of PSCs. It has been previously shown that treatment of stem cells with a low concentration of dimethyl sulfoxide (DMSO) significantly increases the propensity of a variety of PSCs to differentiate to different cell types following directed differentiation. This technique has now been shown to be effective across different species (e.g., mouse, primate, and human) into multiple lineages, ranging from neurons and cortical spheroids to smooth muscle cells and hepatocytes. The DMSO pretreatment improves PSC differentiation by regulating the cell cycle and priming stem cells to be more responsive to differentiation signals. Provided here is the detailed methodology for using this simple tool as a reproducible and widely applicable means to more efficiently differentiate PSCs to any lineage of choice.

Generating differentiated cell types from human pluripotent stem cells (hPSCs) holds great therapeutic promise but remains challenging. PSCs often exhibit an inherent inability to differentiate even when stimulated with a proper set of signals. Described here is a simple tool to enhance multilineage differentiation across a variety of PSC lines.

Despite the growing use of pluripotent stem cells (PSCs), challenges in efficiently differentiating embryonic and induced pluripotent stem cells (ESCs and ...

Efficient Neural Differentiation using Single-Cell Culture of Human Embryonic Stem Cells

In vitro differentiation of human embryonic stem cells (hESCs) has transformed the ability to study human development on both biological and molecular levels and provided cells for use in regenerative applications. Standard approaches for hESC culture using colony type culture to maintain undifferentiated hESCs and embryoid body (EB) and rosette formation for differentiation into different germ layers are inefficient and time-consuming. Presented here is a single-cell culture method using hESCs instead of a colony-type culture. This method allows maintenance of the characteristic features of undifferentiated hESCs, including expression of hESC markers at levels comparable to colony type hESCs. In addition, the protocol presents an efficient method for neural progenitor cell (NPC) generation from single-cell type hESCs that produces NPCs within 1 week. These cells highly express several NPC marker genes and can differentiate into various neural cell types, including dopaminergic neurons and astrocytes. This single-cell culture system for hESCs will be useful in investigating the molecular mechanisms of these processes, studies of certain diseases, and drug discovery screens.

Presented here is a protocol for the generation of a single-cell culture of human embryonic stem cells and their subsequent differentiation into neural progenitor cells. The protocol is simple, robust, scalable, and suitable for drug screening and regenerative medicine applications.

In vitro differentiation of human embryonic stem cells (hESCs) has transformed the ability to study human development on both biological and molecular ...

Derivation of Adult Human Fibroblasts and their Direct Conversion into Expandable Neural Progenitor Cells

Generation of&#160;induced pluripotent stem cell (iPSCs) from adult skin fibroblasts and subsequent differentiation into somatic cells provides fascinating prospects for the derivation of autologous transplants that circumvent histocompatibility barriers. However, progression through a pluripotent state and subsequent complete differentiation into desired lineages remains a roadblock for the clinical translation of iPSC technology because of the associated neoplastic potential and genomic instability. Recently, we and others showed that somatic cells cannot only be converted into iPSCs but also into different types of multipotent somatic stem cells by using defined factors, thereby circumventing progression through the pluripotent state. In particular, the direct conversion of human fibroblasts into induced neural progenitor cells (iNPCs) heralds the possibility of a novel autologous cell source for various applications such as cell replacement, disease modeling and drug screening. Here, we describe the isolation of adult human primary fibroblasts by skin biopsy and their efficient direct conversion into iNPCs by timely restricted expression of Oct4, Sox2, Klf4, as well as c-Myc. Sox2-positive neuroepithelial colonies appear after 17 days of induction and iNPC lines can be established efficiently by monoclonal isolation and expansion. Precise adjustment of viral multiplicity of infection and supplementation of leukemia inhibitory factor during the induction phase represent critical factors to achieve conversion efficiencies of up to 0.2%. Thus far, patient-specific iNPC lines could be expanded for more than 12 passages and uniformly display morphological and molecular features of neural stem/progenitor cells, such as the expression of Nestin and Sox2. The iNPC lines can be differentiated into neurons and astrocytes as judged by staining against TUJ1 and GFAP, respectively. In conclusion, we report a robust protocol for the derivation and direct conversion of human fibroblasts into stably expandable neural progenitor cells that might provide a cellular source for biomedical applications such as autologous neural cell replacement and disease modeling.

Generation of induced pluripotent stem cells provides fascinating prospects for the derivation of autologous transplants. However, progression through a pluripotent state and laborious re-differentiation still hinders clinical translation. Here we describe the derivation of adult human fibroblasts and their direct conversion into induced neural progenitor cells and the subsequent differentiation into neural lineages.

Generation of&#160;induced pluripotent stem cell (iPSCs) from adult skin fibroblasts and subsequent differentiation into somatic cells provides ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Biology

Selecting and Isolating Colonies of Human Induced Pluripotent Stem Cells Reprogrammed from Adult Fibroblasts

Herein we present a protocol of reprogramming human adult fibroblasts into human induced pluripotent stem cells (hiPSC) using retroviral vectors encoding Oct3/4, Sox2, Klf4 and c-myc (OSKM) in the presence of sodium butyrate 1-3. We used this method to reprogram late passage (&gt;p10) human adult fibroblasts derived from Friedreich's ataxia patient (GM03665, Coriell Repository). The reprogramming approach includes highly efficient transduction protocol using repetitive centrifugation of fibroblasts in the presence of virus-containing media. The reprogrammed hiPSC colonies were identified using live immunostaining for Tra-1-81, a surface marker of pluripotent cells, separated from non-reprogrammed fibroblasts and manually passaged 4,5. These hiPSC were then transferred to Matrigel plates and grown in feeder-free conditions, directly from the reprogramming plate. Starting from the first passage, hiPSC colonies demonstrate characteristic hES-like morphology. Using this protocol more than 70% of selected colonies can be successfully expanded and established into cell lines. The established hiPSC lines displayed characteristic pluripotency markers including surface markers TRA-1-60 and SSEA-4, as well as nuclear markers Oct3/4, Sox2 and Nanog. 
The protocol presented here has been established and tested using adult fibroblasts obtained from Friedreich's ataxia patients and control individuals 6, human newborn fibroblasts, as well as human keratinocytes.

We present a protocol for efficient reprogramming of human somatic cells into human induced pluripotent stem cells (hiPSC) using retroviral vectors encoding Oct3/4, Sox2, Klf4 and c-myc (OSKM) and identification of correctly reprogrammed hiPSC by live staining with Tra-1-81 antibody.

Herein we present a protocol of reprogramming human adult fibroblasts into human induced pluripotent stem cells (hiPSC) using retroviral vectors encoding ...

Rapid and Efficient Generation of Neurons from Human Pluripotent Stem Cells in a Multititre Plate Format

Existing protocols for the generation of neurons from human pluripotent stem cells (hPSCs) are often tedious in that they are multistep procedures involving the isolation and expansion of neural precursor cells, prior to terminal differentiation. In comparison to these time-consuming approaches, we have recently found that combined inhibition of three signaling pathways, TGF&beta;/SMAD2, BMP/SMAD1, and FGF/ERK, promotes rapid induction of neuroectoderm from hPSCs, followed by immediate differentiation into functional neurons. Here, we have adapted our procedure to a novel multititre plate format, to further enhance its reproducibility and to make it compatible with mid-throughput applications. It comprises four days of neuroectoderm formation in floating spheres (embryoid bodies), followed by a further four days of differentiation into neurons under adherent conditions. Most cells obtained with this protocol appear to be bipolar sensory neurons. Moreover, the procedure is highly efficient, does not require particular expert skills, and is based on a simple chemically defined medium with cost-efficient small molecules. Due to these features, the procedure may serve as a useful platform for further functional investigation as well as for cell-based screening approaches requiring human sensory neurons or neurons of any type.

Protocols for neuronal differentiation of pluripotent human stem cells (hPSCs) are often time-consuming and require substantial cell culture skills. Here, we have adapted a small molecule-based differentiation procedure to a multititre plate format, allowing simple, rapid, and efficient generation of human neurons in a controlled manner.

Existing protocols for the generation of neurons from human pluripotent stem cells (hPSCs) are often tedious in that they are  multistep procedures ...

Derivation and Characterization of a Transgene-free Human Induced Pluripotent Stem Cell Line and Conversion into Defined Clinical-grade Conditions

Human induced pluripotent stem cells (hiPSCs) can be generated with lentiviral-based reprogramming methodologies. However, traces of potentially oncogenic genes remaining in actively transcribed regions of the genome, limit their potential for use in human therapeutic applications1. Additionally, non-human antigens derived from stem cell reprogramming or differentiation into therapeutically relevant derivatives preclude these hiPSCs from being used in a human clinical context2. In this video, we present a procedure for reprogramming and analyzing factor-free hiPSCs free of exogenous transgenes. These hiPSCs then can be analyzed for gene expression abnormalities in the specific intron containing the lentivirus. This analysis may be conducted using sensitive quantitative polymerase chain reaction (PCR), which has an advantage over less sensitive techniques previously used to detect gene expression differences3. Full conversion into clinical-grade good manufacturing practice (GMP) conditions, allows human clinical relevance. Our protocol offers another methodology&#8212;provided that current safe-harbor criteria will expand and include factor-free characterized hiPSC-based derivatives for human therapeutic applications&#8212;for deriving GMP-grade hiPSCs, which should eliminate any immunogenicity risk due to non-human antigens. This protocol is broadly applicable to lentiviral reprogrammed cells of any type and provides a reproducible method for converting reprogrammed cells into GMP-grade conditions.

We describe a protocol for deriving lentiviral-based reprogrammed and characterized factor-free human induced pluripotent stem cells and conversion into putative clinical-grade conditions.

Human induced pluripotent stem cells (hiPSCs) can be generated with lentiviral-based reprogramming methodologies. However, traces of potentially oncogenic ...

A Two-Step Strategy that Combines Epigenetic Modification and Biomechanical Cues to Generate Mammalian Pluripotent Cells

Cell phenotype can be reversed or modified with different methods, with advantages and limitations that are specific for each technique. Here we describe a new strategy that combines the use of chemical epigenetic erasing with mechanosensing-related cues, to generate mammalian pluripotent cells. Two main steps are required. In the first step, adult mature (terminally differentiated) cells are exposed to the epigenetic eraser 5-aza-cytidine to drive them into a pluripotent state. This part of the protocol was developed, based on the increasing understanding of the epigenetic mechanisms controlling cell fate and differentiation, and involves the use of the epigenetic modifier to erase cell differentiated state and then drive into a transient high plasticity window.
In the second step, erased cells are encapsulated in polytetrafluoroethylene (PTFE) micro-bioreactors, also known as Liquid Marbles, to promote 3D cell rearrangement to extend and stably maintain the acquired high plasticity. PTFE is a non-reactive hydrophobic synthetic compound and its use permits the creation of a cellular microenvironment, which cannot be achieved in traditional 2D culture systems. This system encourages and boosts the maintenance of pluripotency though bio-mechanosensing-related cues.
The technical procedures described here are simple strategies to allow for the induction and maintenance of a high plasticity state in adult somatic cells. The protocol allowed the derivation of high plasticity cells in all mammalian species tested. Since it does not involve the use of gene transfection and is free of viral vectors, it may represent a notable technological advance for translational medicine applications. Furthermore, the micro-bioreactor system provides a notable advancement in stem cell organoid technology by in vitro re-creating a specific micro-environment that allows for the long-term culture of high plasticity cells, namely as ESCs, iPSCs, epigenetically erased cells and MSCs.

We here present a method that combines the use of chemical epigenetic erasing with mechanosensing-related cues to efficiently generate mammalian pluripotent cells, without the need of gene transfection or retroviral vectors. This strategy is, therefore, promising for translational medicine and represents a notable advancement in stem cell organoid technology.

Cell phenotype can be reversed or modified with different methods, with advantages and limitations that are specific for each technique. Here we describe ...

Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Naïve-like State with Improved Multilineage Differentiation Potency

Samenvatting

Meer video's verkennen