Este trabalho foi financiado pela Yale School of Medicine e Prêmio Criança Pesquisa em Saúde da Fundação Charles capa.

1. Reprogramação por retrovírus Expressando Fatores Reprogramação <ol><li> Fibroblastos humanos são cultivados em meio de fibroblastos (10% de FBS em meio DMEM com Pen / Strep). </li><li> Um dia antes da infecção, placa de 1x10 5 fibroblastos humanos em um poço de uma placa de 6 poços. </li><li> Aspirar meio para remover células mortas e adicionar 2 ml de meio de fibroblastos fresco. Adicionar sulfato de protamina, na concentração final de 5 ug / ml. </li><li> Adicionar cuidadosamente a quantidade apropriada de cada vírus GFP-expressando o que corresponde a uma multiplicidade de infecção (MOI) 5 5. </li><li> Um dia após a infecção, remover o sobrenadante viral, lavar três vezes com 2 ml de PBS, em seguida, adicionar 2 ml médio de fibroblastos. </li><li> Três dias após a infecção, verifique a fluorescência da GFP e repor o bem com 2 ml meio de fibroblastos. </li><li> Quatro dias após a infecção, placa de 1x10 cm 4/2, de fibroblasto do rato irradiado embrionário (MEFs) células de alimentação, em meio de fibroblastos para um10-cm placa de Petri revestidas com 0,1% de gelatina. Incubar a 37 ° C durante a noite. </li><li> Cinco dias após a infecção, separar fibroblastos humanos infectados com 1 ml de 0,05% typsin / EDTA durante 5 minutos a 37 ° C, e centrifuga-se durante 5 minutos a 200 g. Aspirar o meio e ressuspender as células com 10 ml de meio de fibroblastos. Transferir as células em uma placa pré-revestida 10-cm. </li><li> Após 24 horas, substituir o meio com meio de cultura hESC (20% de substituição knock-out soro, DMEM/F12, 0,1 ml Non-aminoácidos essenciais, 4 ng / ml de bFGF, Pen / Strep / glutamato, beta merceptoethanol-). Alterar a média diária. ESC-colônias, como vão começar a aparecer durante o dia 20-27 após a infecção. </li></ol> 2. Isolamento e Expansão das iPSCs <ol><li> Sob um microscópio de fluorescência, para verificar a ausência de GFP fluorescência em uma colónia que mostra uma morfologia semelhante à hESCs. </li><li> Usando uma pipeta de 10 ul, escolha colônias individuais da IPSC e colocá-los em um poço de uma gelatina e MEF-coated placa 12 poços e suplementado com meio de hESC. Alterar média diária. </li><li> Para passaging, lavar a placa com 1 ml de DMEM/F12, em seguida, adicionar 0,5 ml de colagenase, e incubar durante 10 minutos a 37 ° C. </li><li> Lave as células duas vezes com DMEM/F12. </li><li> Adicionar 2 ml de meio fresco hESC. Usando um levantador célula, romper as colónias em pedaços pequenos e separar células restantes a partir da placa. </li><li> Transfira os pedaços de colónias ressuspensos em um poço de uma gelatina, e MEF-revestido placa de 6 poços. </li></ol> 3. Análise de marcadores de imunofluorescência pluripotentes <ol><li> Lave as células três vezes com PBS e fixar com paraformaldeído a 4% durante 20 min à temperatura ambiente. </li><li> Suavemente lavar as células três vezes com PBS e permeabilizar com 0,2% de Triton X-100 em PBS durante 30 min. </li><li> Bloquear a ligação não específica através da incubação de células com BSA a 3% em PBS durante duas horas. </li><li> Incubar as células com anticorpo primário durante a noite a 4 ° C. </li> &lt;li&gt; Lave as células três vezes com PBS e incubar as células com anticorpo secundário específico para uma hora à temperatura ambiente, protegendo da luz. </li><li> Lave as células três vezes com PBS e DAPI extra durante a última lavagem, seguido por incubação à temperatura ambiente durante 5 minutos. </li><li> Detectar a coloração com um microscópio de fluorescência. </li></ol> 4. Quantitativo em tempo real PCR para os marcadores pluripotentes <ol><li> Isolar o RNA total a partir dos derivados de humanos iPSCs fibroblastos humanos usando o kit Qiagen RNeasy do. </li><li> Sintetizar o cDNA fita-primeiro usando SuperScript Transcriptase Reversa II. </li><li> Execute qPCR para detectar genes de pluripotência usando primers previamente relatados. 6 </li></ol> 5. Os resultados representativos <ol><li> Mudança morfológica durante a reprogramação Nós fibroblastos humanos infectados BJ1 e Detroit 551 com um coquetel de retrovírus que transportam Oct4, Sox2, KLF4 e MYC,e foram capazes de detectar alterações morfológicas durante reprogramação (Figura 1). Vinte e um dias após a infecção, reconhecemos pequenas colónias IPSC pela sua morfologia hESC-like. Além disso, reconhecemos iPSCs pela fluorescência da GFP. As células estaminais pluripotentes, tais como CES e iPSCs, expressam a maquinaria molecular para reprimir a expressão do gene proviral 7-9. O nosso vector retroviral única expressa GFP em conjunto com genes de reprogramação por LTR retroviral. Assim, as células que expressam GFP continuamente são considerados expressar transgenes sem silenciamento do gene proviral. Fielmente reprogramadas colónias IPSC que adquirem a rede pluripotência molecular mostram a ausência de expressão da GFP (Figura 2) 10. </li><li> Caracterização da pluripotência das iPSCs humanos Analisou-se as colónias derivadas de Detroit-551 fibroblastos através imuno-histoquímica com Tra-1-81, Tra-1-60, SSEA-4, SSEA-3, Oct4 e anticorpos NANOG ( <strong&gt; Tabela 2). IPSCs com sucesso reprogramadas expressar todos estes marcadores (Figura 3A). Foram também analisadas a expressão do gene através de análise quantitativa de RT-PCR. Observou-se que a expressão de Oct4, SOX2, KLF4, myc e NANOG foi significativamente aumentada em comparação com as células de fibroblasto parental mas em proporção com a de H9 hESCs (Figura 3B). </li></ol><img alt="A Figura 1" src="/files/ftp_upload/3804/3804fig1.jpg" /> Figura 1. As alterações morfológicas de retrovírus infectados fibroblastos humanos. (AD) mudança morfológica Progressive em colônias de Detroit-551 fibroblastos infectados com fatores de reprogramação. Dia 5 (A), Dia 10 (B), Dia 14 (C), dia 21 (D). As células mostram a morfologia hESC-like após 21 dias. <img alt="A Figura 2" src="/files/ftp_upload/3804/3804fig2.jpg" /> Figura 2. Representante expressão da GFP fluorescente em células submetidas a reprogramação. </strong&gt; BJ e Detroit 551 fibroblastos foram infectadas com retrovírus expressando quatro factores de reprogramação 4, e incubadas em meio hESC durante quatro semanas. Fibroblastos BJ (A, B) e Detroit 551 (C, D) mostram semelhante morfológica. A partir do dia 21 de colônias GFP negativos começam a se formar, que representam as iPSCs de boa-fé 10. (E, F) mostram transformada Detroit 551 células que não tenham sido submetidos a reprogramação adequada. (A, C, E) colónias sob visão de contraste de fase. (B, D) adequadamente reprogramado células que mostram o silenciamento GFP. (F) expressão GFP brilhante de colônia transformada. <img alt="A Figura 3" src="/files/ftp_upload/3804/3804fig3.jpg" /> Figura 3. Caracterização das células estaminais pluripotentes induzidas. (A) colónias Humanos 551-IPS-K1 de células expressam marcadores comuns para as células pluripotentes. Coloração DAPI indica o teor total de células por campo. (B) quantitativa em tempo real-PCR (RT-qPCR) para a expressão de Oct4, SOX2, KLF4, myc em f parentalibroblast e 551-iPS-K1 iPSCs e H9 células estaminais embrionárias humanas (hESCs). Os dados foram normalizados contra β-actina gene de limpeza e traçada em relação ao nível de expressão nas células de fibroblasto parental 4.

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<p class="jove_content"&gt; Não temos nada a divulgar.</p

Expressão de quatro fatores de transcrição reprograma fibroblastos humanos para iPSCs. Muitas tentativas foram feitas para gerar iPSCs humanos utilizando abordagens não integradoras ou não-genética para gerar iPSCs clinicamente seguros. Até agora, esses métodos mostram eficiência extremamente baixa e exigem otimização para melhorar a reprodutibilidade 11-14. Métodos de retro-ou lentiviral são prontamente utilizados para obter e aplicar iPSCs para o homem em modelos de doenças <...

<table border="1">
	<tbody>
		<tr>
			<td>Name</td>
			<td>Concentration</td>
			<td>Company</td>
			<td>Catalogue Number</td>
		</tr>
		<tr>
			<td colspan="4">hESC medium</td>
		</tr>
		<tr>
			<td>DMEM/F12</td>
			<td>80%</td>
			<td>Invitrogen</td>
			<td>11330057</td>
		</tr>
		<tr>
			<td>Knockout Serum Replacer</td>
			<td>20%</td>
			<td>Invitrogen</td>
			<td>10828-028</td>
		</tr>
		<tr>
			<td>L-Glutamine (200 mM)</td>
			<td>2 mM</td>
			<td>Invitrogen</td>
			<td>25030081</td>
		</tr>
		<tr>
			<td>Nonessential Amino Acids (10 mM)</td>
			<td>0.1 mM</td>
			<td>Invitrogen</td>
			<td>11140050</td>
		</tr>
		<tr>
			<td>&beta;-Mercaptoethanol (14.3 M) or MTG</td>
			<td>0.1 mM</td>
			<td>Invitrogen</td>
			<td>M-6250</td>
		</tr>
		<tr>
			<td>bFGF-2 10 &mu;g/ml</td>
			<td>4 ng/ml</td>
			<td>GIBCO/BRL</td>
			<td>GF003AF</td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>1%</td>
			<td>Millipore</td>
			<td>15140-122</td>
		</tr>
		<tr>
			<td colspan="4">Fiboblasts Medium</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>90%</td>
			<td>Invitrogen</td>
			<td>11965118</td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>10%</td>
			<td>Invitrogen</td>
			<td>10407028</td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>1%</td>
			<td>Millipore</td>
			<td>15140-122</td>
		</tr>
	</tbody>
</table>
Table 1. Culture Medium
<table border="1">
	<tbody>
		<tr>
			<td>Name</td>
			<td>Concentration</td>
			<td>Company</td>
			<td>Catalogue Number</td>
		</tr>
		<tr>
			<td colspan="4">Antibodies</td>
		</tr>
		<tr>
			<td>OCT4</td>
			<td>1:500</td>
			<td>Abcam</td>
			<td>Ab19857</td>
		</tr>
		<tr>
			<td>SSEA3</td>
			<td>1:100</td>
			<td>Milipore</td>
			<td>MAB4303</td>
		</tr>
		<tr>
			<td>SSEA4</td>
			<td>1:100</td>
			<td>BD Biosciences</td>
			<td>BD560218</td>
		</tr>
		<tr>
			<td>Tra-1-81</td>
			<td>1:100</td>
			<td>BD Biosciences</td>
			<td>BD560173</td>
		</tr>
		<tr>
			<td>Tra-1-60</td>
			<td>1:100</td>
			<td>BD Biosciences</td>
			<td>BD560174</td>
		</tr>
		<tr>
			<td>NANOG</td>
			<td>1:500</td>
			<td>Abcam</td>
			<td>Ab21624</td>
		</tr>
		<tr>
			<td>Alexa-Flur 488</td>
			<td>1:1000</td>
			<td>Invitrogen</td>
			<td>A11008</td>
		</tr>
		<tr>
			<td>Alexa-Flur 555</td>
			<td>1:1000</td>
			<td>Invitrogen</td>
			<td>A21422</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>1:5000</td>
			<td>Invitrogen</td>
			<td>D1306</td>
		</tr>
		<tr>
			<td colspan="4">Plasmids</td>
		</tr>
		<tr>
			<td>pMIG-OCT4</td>
			<td>&nbsp;</td>
			<td>Addgene</td>
			<td>17225</td>
		</tr>
		<tr>
			<td>pMIG-SOX2</td>
			<td>&nbsp;</td>
			<td>Addgene</td>
			<td>17226</td>
		</tr>
		<tr>
			<td>pMIG-KLF4</td>
			<td>&nbsp;</td>
			<td>Addgene</td>
			<td>17227</td>
		</tr>
		<tr>
			<td>pMIG-MYC</td>
			<td>&nbsp;</td>
			<td>Addgene</td>
			<td>18119</td>
		</tr>
		<tr>
			<td colspan="4">Other Materials</td>
		</tr>
		<tr>
			<td>Collagenase type IV</td>
			<td>1mg/ml</td>
			<td>Invitrogen</td>
			<td>17104019</td>
		</tr>
		<tr>
			<td>Gelatin, Porcine</td>
			<td>0.1%</td>
			<td>Sigma</td>
			<td>G 1890</td>
		</tr>
		<tr>
			<td>Triton</td>
			<td>0.2%</td>
			<td>Sigma</td>
			<td>X100-500ML</td>
		</tr>
		<tr>
			<td>Paraformaldehyde</td>
			<td>4%</td>
			<td>Sigma</td>
			<td>47608</td>
		</tr>
		<tr>
			<td>BSA</td>
			<td>3%</td>
			<td>American Bioanalytical</td>
			<td>AB01800</td>
		</tr>
		<tr>
			<td>MEF feeder cells</td>
			<td>&nbsp;</td>
			<td>Millipore</td>
			<td>PMEF-N</td>
		</tr>
		<tr>
			<td>Cell Lifter</td>
			<td>&nbsp;</td>
			<td>Corning</td>
			<td>3008</td>
		</tr>
		<tr>
			<td colspan="4">Equipment</td>
		</tr>
		<tr>
			<td colspan="4">Fluorescent microscopy: inverted microscope with GFP filter</td>
		</tr>
	</tbody>
</table>
Table 2. Reagents and equipment.

reprogramming human somatic cells into induced pluripotent stem cells (ipscs) using retroviral vector with gfp

Células estaminais embrionárias humanas (hESCs) são pluripotentes e uma fonte de valor inestimável para celulares in vitro de modelagem de doenças e medicina regenerativa 1. Já foi demonstrado que as células somáticas humanas pode ser reprogramado para pluripotência pela expressão ectópica dos quatro fatores de transcrição (Oct4, Sox2, KLF4 e Myc) e tornar-se células-tronco pluripotentes induzidas (iPSCs) 2-4. Como hESCs, iPSCs humanas são pluripotentes e uma fonte potencial de células autólogas. Aqui nós descrevemos o protocolo de reprogramar células de fibroblastos humanos, com os quatro fatores de reprogramação clonados em GFP contendo backbone retroviral 4. Usando o protocolo seguinte, geramos iPSCs humanos em 3-4 semanas sob condições de cultura humana ESC. Colónias humanos IPSC se assemelham hESCs na morfologia e exibir a perda de fluorescência da GFP como um resultado de silenciamento do transgene retroviral. IPSC colônias isoladas mecanicamente sob microscopia de fluorescênciaep comportar-se de uma maneira semelhante à hESCs. Nestas células, nós detectar a expressão de vários genes pluripotência e marcadores de superfície.

Watch this Scientific Journal Video about Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells iPSCs Using Retroviral Vector with GFP at JoVE.com

Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells iPSCs Using Retroviral Vector with GFP

Um método para gerar células tronco pluripotentes induzidas (iPSCs) através de expressão retrovírus mediada ectópica de Oct4, SOX2, KLF4 e MYC é descrito. Uma maneira prática de identificar humanos colônias de IPSC com base na expressão de GFP também é discutida.

Reprogramação de células somáticas humanas em células tronco pluripotentes induzidas (iPSCs) usando vetor retroviral com GFP

Human embryonic stem cells (hESCs) are pluripotent and an invaluable cellular sources for in vitro disease modeling and regenerative medicine1. It has ...

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Research

JoVE Journal

Biology

Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells (iPSCs) Using Retroviral Vector with GFP

20.3K visualizações.  Yale School of Medicine. Um método para gerar células tronco pluripotentes induzidas (iPSCs) através de expressão retrovírus mediada ectópica de Oct4, SOX2, KLF4 e MYC é descrito. Uma maneira prática de identificar humanos colônias de IPSC com base na expressão de GFP também é discutida.

Vídeo: Reprogramming Human Somatic Cells into Induced Pluripotent Stem Cells iPSCs Using Retroviral Vector with GFP

Generation of Induced Pluripotent Stem Cells by Reprogramming Mouse Embryonic Fibroblasts with a Four Transcription Factor, Doxycycline Inducible Lentiviral Transduction System

Using a defined set of transcription factors and cell culture conditions, Yamanaka and colleagues demonstrated that retrovirus-mediated delivery and expression of Oct4, Sox2, c-Myc, and Klf4 is capable of inducing pluripotency in mouse fibroblasts.1 Subsequent reports have demonstrated the utility of the doxycycline (DOX) inducible lentiviral delivery system for the generation of both primary and secondary iPS cells from a variety of other adult mouse somatic cell types.2,3
Induced pluripotent stem (iPS) cells are similar to embryonic stem (ES) cells in morphology, proliferation and ability to induce teratoma formation. Both types of cell can be used as the pluripotent starting material for the generation of differentiated cells or tissues in regenerative medicine.4-6 iPS cells also have a distinct advantage over ES cells as they exhibit key properties of ES cells without the ethical dilemma of embryo destruction.
Here we demonstrate the protocol for reprogramming mouse embryonic fibroblast (MEF) cells with the Stemgent DOX Inducible Mouse TF Lentivirus Set. We also demonstrate that the Stemgent DOX Inducible Mouse TF Lentivirus Set is capable of expressing each of the four transcription factors upon transduction into MEFs thereby inducing a pluripotent stem cell state that displays the pluripotency markers characteristic of ES cells.

The Stemgent Dox Inducible Mouse TF Lentivirus Set can reprogram mouse embryonic fibroblasts (MEFs) to induced pluripotent stem (iPS) cells. Here we demonstrate the protocol for DOX-inducible expression of mouse reprogramming transcription factors Oct4, Sox2, Klf4 and c-Myc to generate iPS colonies that express common mES pluripotency markers.

Geração de células-tronco pluripotentes induzidas pela reprogramação fibroblastos de rato embrionárias com um fator de transcrição Quatro, Doxiciclina induzível Sistema de Transdução Lentivirus

Using a defined set of transcription factors and cell culture conditions, Yamanaka and colleagues demonstrated that retrovirus-mediated delivery and ...

Biologia

Generation of Induced Pluripotent Stem Cells by Reprogramming Human Fibroblasts with the Stemgent Human TF Lentivirus Set

In 2006, Yamanaka and colleagues first demonstrated that retrovirus-mediated delivery and expression of Oct4, Sox2, c-Myc and Klf4 is capable of inducing the pluripotent state in mouse fibroblasts.1 The same group also reported the successful reprogramming of human somatic cells into induced pluripotent stem (iPS) cells using human versions of the same transcription factors delivered by retroviral vectors.2 Additionally, James Thomson et al. reported that the lentivirus-mediated co-expression of another set of factors (Oct4, Sox2, Nanog and Lin28) was capable of reprogramming human somatic cells into iPS cells.3
iPS cells are similar to ES cells in morphology, proliferation and the ability to differentiate into all tissue types of the body. Human iPS cells have a distinct advantage over ES cells as they exhibit key properties of ES cells without the ethical dilemma of embryo destruction. The generation of patient-specific iPS cells circumvents an important roadblock to personalized regenerative medicine therapies by eliminating the potential for immune rejection of non-autologous transplanted cells.
Here we demonstrate the protocol for reprogramming human fibroblast cells using the Stemgent Human TF Lentivirus Set. We also show that cells reprogrammed with this set begin to show iPS morphology four days post-transduction. Using the Stemolecule Y27632, we selected for iPS cells and observed correct morphology after three sequential rounds of colony picking and passaging. We also demonstrate that after reprogramming cells displayed the pluripotency marker AP, surface markers TRA-1-81, TRA-1-60, SSEA-4, and SSEA-3, and nuclear markers Oct4, Sox2 and Nanog.

We demonstrate the protocol for the generation of induced pluripotent stem cells from human somatic cells using lentivirus-mediated delivery of the human factors Oct4, Sox2, Nanog, and Lin28. Pluripotency was confirmed by morphology and the presence of embryonic stem (ES) cell-specific markers.

Geração de células-tronco pluripotentes induzidas pela reprogramação fibroblastos humanos com o Lentivirus TF Stemgent Humanos Set

In 2006, Yamanaka and colleagues first demonstrated that retrovirus-mediated delivery and expression of Oct4, Sox2, c-Myc and Klf4 is capable of inducing ...

Transfecting and Nucleofecting Human Induced Pluripotent Stem Cells

Genetic modification is continuing to be an essential tool in studying stem cell biology and in setting forth potential clinical applications of human embryonic stem cells (HESCs)1. While improvements in several gene delivery methods have been described2-9, transfection remains a capricious process for HESCs, and has not yet been reported in human induced pluripotent stem cells (iPSCs). In this video, we demonstrate how our lab routinely transfects and nucleofects human iPSCs using plasmid with an enhanced green fluorescence protein (eGFP) reporter. Human iPSCs are adapted and maintained as feeder-free cultures to eliminate the possibility of feeder cell transfection and to allow efficient selection of stable transgenic iPSC clones following transfection. For nucleofection, human iPSCs are pre-treated with ROCK inhibitor11, trypsinized into small clumps of cells, nucleofected and replated on feeders in feeder cell-conditioned medium to enhance cell recovery. Transgene-expressing human iPSCs can be obtained after 6 hours. Antibiotic selection is applied after 24 hours and stable transgenic lines appear within 1 week. Our protocol is robust and reproducible for human iPSC lines without altering pluripotency of these cells.

Despite recent advancements in genetic modification, transfection of human embryonic stem cells (HESCs) remains a capricious process. To our knowledge, systematic and efficient methods to transfect human induced pluripotent stem cells (iPSCs) have not been reported. Here, we describe robust protocols to efficiently transfect and nucleofect human iPSCs.

Transfectando e Nucleofecting células-tronco pluripotentes induzidas

Genetic modification is continuing to be an essential tool in studying stem cell biology and in setting forth potential clinical applications of human ...

Preparation of Mouse Embryonic Fibroblast Cells Suitable for Culturing Human Embryonic and Induced Pluripotent Stem Cells

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it is not easy to establish an effective system for culturing these cells. Since the culture conditions can influence gene expression that confers pluripotency in hESCs and hiPSCs, the optimization and standardization of the culture method is crucial.
The establishment of hESC lines was first described by using MEFs as feeder cells and fetal bovine serum (FBS)-containing culture medium2. Next, FBS was replaced with knockout serum replacement (KSR) and FGF2, which enhances proliferation of hESCs3. Finally, feeder-free culture systems enable culturing cells on Matrigel-coated plates in KSR-containing conditioned medium (medium conditioned by MEFs)4. Subsequently, hESCs culture conditions have moved towards feeder-free culture in chemically defined conditions5-7. Moreover, to avoid the potential contamination by pathogens and animal proteins culture methods using xeno-free components have been established8.
To obtain improved conditions mouse feeder cells have been replaced with human cell lines (e.g. fetal muscle and skin cells9, adult skin cells10, foreskin fibroblasts11-12, amniotic mesenchymal cells13). However, the efficiency of maintaining undifferentiated hESCs using human foreskin fibroblast-derived feeder layers is not as high as that from mouse feeder cells due to the lower level of secretion of Activin A14. Obviously, there is an evident difference in growth factor production by mouse and human feeder cells.
Analyses of the transcriptomes of mouse and human feeder cells revealed significant differences between supportive and non-supportive cells. Exogenous FGF2 is crucial for maintaining self-renewal of hESCs and hiPSCs, and has been identified as a key factor regulating the expression of Tgf&beta;1, Activin A and Gremlin (a BMP antagonist) in feeder cells. Activin A has been shown to induce the expression of OCT4, SOX2, and NANOG in hESCs15-16.
For long-term culture, hESCs and hiPSCs can be grown on mitotically inactivated MEFs or under feeder-free conditions in MEF-CM (MEF-Conditioned Medium) on Matrigel-coated plates to maintain their undifferentiated state. Success of both culture conditions fully depends on the quality of the feeder cells, since they directly affect the growth of hESCs.
Here, we present an optimized method for the isolation and culture of mouse embryonic fibroblasts (MEFs), preparation of conditioned medium (CM) and enzyme-linked immunosorbent assay (ELISA) to assess the levels of Activin A within the media.

The quality of mouse embryonic fibroblasts (MEFs) is dictated by the right strain of mouse such as CF-1. Pluripotency-supportive MEFs and conditioned media (CM) obtained from these should contain optimal concentrations of Activin A, Gremlin and Tgf&beta;1 needed for the Activin/Nodal and FGF pathways to co-operatively maintain self-renewal and pluripotency.

Preparação de células embrionárias de camundongos Fibroblastos adequados para a cultura de células-tronco embrionárias humanas e pluripotentes induzidas

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it ...

Generation of Human Induced Pluripotent Stem Cells from Peripheral Blood Using the STEMCCA Lentiviral Vector

Through the ectopic expression of four transcription factors, Oct4, Klf4, Sox2 and cMyc, human somatic cells can be converted to a pluripotent state, generating so-called induced pluripotent stem cells (iPSCs)1-4. Patient-specific iPSCs lack the ethical concerns that surround embryonic stem cells (ESCs) and would bypass possible immune rejection. Thus, iPSCs have attracted considerable attention for disease modeling studies, the screening of pharmacological compounds, and regenerative therapies5.
We have shown the generation of transgene-free human iPSCs from patients with different lung diseases using a single excisable polycistronic lentiviral Stem Cell Cassette (STEMCCA) encoding the Yamanaka factors6. These iPSC lines were generated from skin fibroblasts, the most common cell type used for reprogramming. Normally, obtaining fibroblasts requires a skin punch biopsy followed by expansion of the cells in culture for a few passages. Importantly, a number of groups have reported the reprogramming of human peripheral blood cells into iPSCs7-9. In one study, a Tet inducible version of the STEMCCA vector was employed9, which required the blood cells to be simultaneously infected with a constitutively active lentivirus encoding the reverse tetracycline transactivator. In contrast to fibroblasts, peripheral blood cells can be collected via minimally invasive procedures, greatly reducing the discomfort and distress of the patient. A simple and effective protocol for reprogramming blood cells using a constitutive single excisable vector may accelerate the application of iPSC technology by making it accessible to a broader research community. Furthermore, reprogramming of peripheral blood cells allows for the generation of iPSCs from individuals in which skin biopsies should be avoided (i.e. aberrant scarring) or due to pre-existing disease conditions preventing access to punch biopsies.
Here we demonstrate a protocol for the generation of human iPSCs from peripheral blood mononuclear cells (PBMCs) using a single floxed-excisable lentiviral vector constitutively expressing the 4 factors. Freshly collected or thawed PBMCs are expanded for 9 days as described10,11 in medium containing ascorbic acid, SCF, IGF-1, IL-3 and EPO before being transduced with the STEMCCA lentivirus. Cells are then plated onto MEFs and ESC-like colonies can be visualized two weeks after infection. Finally, selected clones are expanded and tested for the expression of the pluripotency markers SSEA-4, Tra-1-60 and Tra-1-81. This protocol is simple, robust and highly consistent, providing a reliable methodology for the generation of human iPSCs from readily accessible 4 ml of blood.

Here we show a simple and effective protocol for the generation of human iPSCs from 3-4 ml of peripheral blood using a single lentiviral reprogramming vector. Reprogramming of readily available blood cells promises to accelerate the utilization of iPSC technology by making it accessible to a broader research community.

Geração de Células-tronco pluripotentes induzidas a partir de sangue periférico usando o STEMCCA Lentivirus Vector

Through the ectopic expression of four transcription factors, Oct4, Klf4, Sox2 and cMyc, human somatic cells can be converted to a pluripotent state, ...

In vivo Reprogramming of Adult Somatic Cells to Pluripotency by Overexpression of Yamanaka Factors

Induced pluripotent stem (iPS) cells that result from the reprogramming of somatic cells to a pluripotent state by forced expression of defined factors are offering new opportunities for regenerative medicine. Such clinical applications of iPS cells have been limited so far, mainly due to the poor efficiency of the existing reprogramming methodologies and the risk of the generated iPS cells to form tumors upon implantation.
We hypothesized that the reprogramming of somatic cells towards pluripotency could be achieved in vivo by gene transfer of reprogramming factors. In order to efficiently reprogram cells in vivo, high levels of the Yamanaka (OKSM) transcription factors need to be expressed at the target tissue. This can be achieved by using different viral or nonviral gene vectors depending on the target tissue. In this particular study, hydrodynamic tail-vein (HTV) injection of plasmid DNA was used to deliver the OKSM factors to mouse hepatocytes. This provided proof-of-evidence of in vivo reprogramming of adult, somatic cells towards a pluripotent state with high efficiency and fast kinetics. Furthermore no tumor or teratoma formation was observed in situ.
It can be concluded that reprogramming somatic cells in vivo may offer a potential approach to induce enhanced pluripotency rapidly, efficiently, and safely compared to in vitro performed protocols and can be applied to different tissue types in the future.

In vivo Reprogramming of Adult Somatic Cells to Pluripotency by Overexpression of Yamanaka Factors

This study demonstrates the reprogramming of somatic cells towards pluripotency in vivo without the generation of teratomas. We used hydrodynamic tail vein injection of plasmid DNA encoding the Yamanka factors to induce the in vivo reprogramming of adult hepatocytes into cells of enhanced pluripotency.

In vivo Reprogramação de células adultas somáticas a pluripotência por superexpressão de Fatores de Yamanaka

Induced pluripotent stem (iPS) cells that result from the reprogramming of somatic cells to a pluripotent state by forced expression of defined factors ...

Efficient Generation Human Induced Pluripotent Stem Cells from Human Somatic Cells with Sendai-virus

A few years ago, the establishment of human induced pluripotent stem cells (iPSCs) ushered in a new era in biomedicine. Potential uses of human iPSCs include modeling pathogenesis of human genetic diseases, autologous cell therapy after gene correction, and personalized drug screening by providing a source of patient-specific and symptom relevant cells. However, there are several hurdles to overcome, such as eliminating the remaining reprogramming factor transgene expression after human iPSCs production. More importantly, residual transgene expression in undifferentiated human iPSCs could hamper proper differentiations and misguide the interpretation of disease-relevant in vitro phenotypes. With this reason, integration-free and/or transgene-free human iPSCs have been developed using several methods, such as adenovirus, the piggyBac system, minicircle vector, episomal vectors, direct protein delivery and synthesized mRNA. However, efficiency of reprogramming using integration-free methods is quite low in most cases.
Here, we present a method to isolate human iPSCs by using Sendai-virus (RNA virus) based reprogramming system. This reprogramming method shows consistent results and high efficiency in cost-effective manner.

Here, we present our established method to reprogram human somatic cells into transgene-free human iPSCs with Sendai virus, which shows consistent outcome and enhanced efficiency.

Eficiente Geração induzida pelo homem células-tronco pluripotentes a partir de células somáticas humanas com Sendai-vírus

A few years ago, the establishment of human induced pluripotent stem cells (iPSCs) ushered in a new era in biomedicine. Potential uses of human iPSCs ...

Episomal Reprogramming of Dermal Fibroblasts to Generate Human-Induced Pluripotent Stem Cells (hiPSCs)

Episomal Reprogramming of Dermal Fibroblasts to Generate Human-Induced Pluripotent Stem Cells (HiPSCs)  

To begin, take a flask of cultured fibroblast cells, coat a 10-centimeter cell culture plate suitable for hiPSC culture with four milliliters of cold coating solution per plate, and incubate the plate for one hour at 37 degrees Celsius. Afterward, remove the media from the fibroblasts and wash them with four milliliters of pre-warmed PBS per flask. Aspirate the PBS and associate the fibroblasts with four milliliters of Trypsin-EDTA per flask by incubating for five to seven minutes at 37 degrees Celsius.Monitor cell detachment using a phase contrast microscope, and if needed, tap against the side of the flask to detach the cells from the plastic surface. Transfer the detached cells to a 50-milliliter conical tube and wash the empty flasks with six milliliters of pre-warmed fibroblast medium. Collect and pool the remaining cells in the conical tube.Then centrifuge the cells at 200 g for five minutes at 20 degrees Celsius. Aspirate the supernatant and re-suspend the cell pellet in three milliliters of fresh, pre-warmed PBS. Count the cells, transfer 1.5 times 10 to the sixth fibroblasts into a new conical tube and fill up with PBS to the five millimeter mark.Centrifuge the tube at 200 g for five minutes at 20 degrees Celsius. Discard the supernatant, re-suspend the cell pellet in five milliliters of electroporation medium, and centrifuge again. In the meantime, aspirate the coating solution from the coated 10-centimeter cell culture plate and add seven milliliters of pre-warmed fibroblast medium.At the end of the centrifugation, discard the supernatant and re-suspend the cell pellet in electroporation medium with a concentration of 1.5 times 10 to the sixth cells in 250 microliters. Transfer the 250 microliter cell suspension to an electroporation cuvette with a four millimeter gap distance. Next, prepare a plasma transfection mix by adding four micrograms of each plasmid to a total volume of 50 microliters of electroporation medium.Transfer the transfection mix to the cuvette, mix gently by flicking, and electroporate with one pulse at 280 volts. Finally, transfer 150 microliters of the electroporated fibroblasts to the prepared 10-centimeter cell culture plate. Agitate the plate thrice in all directions to distribute the cells, and incubate overnight.Fibroblasts present in a long, spindle-like phenotype, the size of 150 to 300 nanometers. After reprogramming, colonies with 50 micrometer small hiPSCs occur displaying distinct borders. The hiPSCs are distinguished by a high nuclei to body ratio and increased proliferation rate.

Reprogramação Epissomal de Fibroblastos Dérmicos para Gerar Células-Tronco Pluripotentes Induzidas pelo Homem (hiPSCs)

Generation and Maintenance of Primate Induced Pluripotent Stem Cells Derived from Urine

Cross-species approaches studying primate pluripotent stem cells and their derivatives are crucial to better understand the molecular and cellular mechanisms of disease, development, and evolution. To make primate induced pluripotent stem cells (iPSCs) more accessible, this paper presents a non-invasive method to generate human and non-human primate iPSCs from urine-derived cells, and their maintenance using a feeder-free culturing method.
The urine can be sampled from a non-sterile environment (e.g., the cage of the animal) and treated with a broad-spectrum antibiotic cocktail during primary cell culture to reduce contamination efficiently. After propagation of the urine-derived cells, iPSCs are generated by a modified transduction method of a commercially available Sendai virus vector system. First&#160;iPSC colonies may already be visible after 5 days, and can be picked after 10 days at the earliest. Routine clump passaging with enzyme-free dissociation buffer supports pluripotency of the generated iPSCs for more than 50 passages.

The present protocol describes a method to isolate, expand, and reprogram human and non-human primate urine-derived cells to induced pluripotent stem cells (iPSCs), as well as instructions for feeder-free maintenance of the newly generated iPSCs.

Geração e Manutenção de Células-Tronco Pluripotentes Induzidas por Primatas Derivadas da Urina

Cross-species approaches studying primate pluripotent stem cells and their derivatives are crucial to better understand the molecular and cellular ...

Caracterização de antígenos de superfície e capacidade de proliferação em MSCs acionadoras de hiPSC

Comparison of Two Representative Methods for Differentiation of Human Induced Pluripotent Stem Cells into Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) are adult pluripotent stem cells which have been widely used in regenerative medicine. As somatic tissue-derived MSCs are restricted by limited donation, quality variations, and biosafety, the past 10 years have seen a great rise in efforts to generate MSCs from human induced pluripotent stem cells (hiPSCs). Past and recent efforts in the differentiation of hiPSCs into MSCs have been centered around two culture methodologies: (1) the formation of embryoid bodies (EBs) and (2) the use of monolayer culture. This protocol describes these two representative methods in deriving MSC from hiPSCs. Each method presents its advantages and disadvantages, including time, cost, cell proliferation ability, the expression of MSC markers, and their capability of differentiation in vitro. This protocol demonstrates that both methods can derive mature and functional MSCs from hiPSCs. The monolayer method is characterized by lower cost, simpler operation, and easier osteogenic differentiation, while the EB method is characterized by lower time consumption.

Autor em destaque: Avanços em iPSCs e pesquisa de doenças genéticas 

This protocol describes and compares two representative methods for differentiating hiPSCs into mesenchymal stromal cells (MSCs). The monolayer method is characterized by lower cost, simpler operation, and easier osteogenic differentiation. The embryoid bodies (EBs) method is characterized by lower time consumption.

Comparação de Dois Métodos Representativos para Diferenciação de Células-Tronco Pluripotentes Induzidas por Humanos em Células Estromais Mesenquimais

Mesenchymal stromal cells (MSCs) are adult pluripotent stem cells which have been widely used in regenerative medicine. As somatic tissue-derived MSCs are ...