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1.
Nat Commun ; 11(1): 5061, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033262

RESUMO

The interplay between the Yamanaka factors (OCT4, SOX2, KLF4 and c-MYC) and transcriptional/epigenetic co-regulators in somatic cell reprogramming is incompletely understood. Here, we demonstrate that the histone H3 lysine 27 trimethylation (H3K27me3) demethylase JMJD3 plays conflicting roles in mouse reprogramming. On one side, JMJD3 induces the pro-senescence factor Ink4a and degrades the pluripotency regulator PHF20 in a reprogramming factor-independent manner. On the other side, JMJD3 is specifically recruited by KLF4 to reduce H3K27me3 at both enhancers and promoters of epithelial and pluripotency genes. JMJD3 also promotes enhancer-promoter looping through the cohesin loading factor NIPBL and ultimately transcriptional elongation. This competition of forces can be shifted towards improved reprogramming by using early passage fibroblasts or boosting JMJD3's catalytic activity with vitamin C. Our work, thus, establishes a multifaceted role for JMJD3, placing it as a key partner of KLF4 and a scaffold that assists chromatin interactions and activates gene transcription.


Assuntos
Reprogramação Celular , Histona Desmetilases com o Domínio Jumonji/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Animais , Catálise , Proliferação de Células , Senescência Celular , Desmetilação , Elementos Facilitadores Genéticos/genética , Células Epiteliais/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Histonas/metabolismo , Lisina/metabolismo , Camundongos , Modelos Biológicos , Regiões Promotoras Genéticas , Ativação Transcricional/genética
2.
Proc Natl Acad Sci U S A ; 117(33): 19854-19865, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32759214

RESUMO

The blood-retina barrier and blood-brain barrier (BRB/BBB) are selective and semipermeable and are critical for supporting and protecting central nervous system (CNS)-resident cells. Endothelial cells (ECs) within the BRB/BBB are tightly coupled, express high levels of Claudin-5 (CLDN5), a junctional protein that stabilizes ECs, and are important for proper neuronal function. To identify novel CLDN5 regulators (and ultimately EC stabilizers), we generated a CLDN5-P2A-GFP stable cell line from human pluripotent stem cells (hPSCs), directed their differentiation to ECs (CLDN5-GFP hPSC-ECs), and performed flow cytometry-based chemogenomic library screening to measure GFP expression as a surrogate reporter of barrier integrity. Using this approach, we identified 62 unique compounds that activated CLDN5-GFP. Among them were TGF-ß pathway inhibitors, including RepSox. When applied to hPSC-ECs, primary brain ECs, and retinal ECs, RepSox strongly elevated barrier resistance (transendothelial electrical resistance), reduced paracellular permeability (fluorescein isothiocyanate-dextran), and prevented vascular endothelial growth factor A (VEGFA)-induced barrier breakdown in vitro. RepSox also altered vascular patterning in the mouse retina during development when delivered exogenously. To determine the mechanism of action of RepSox, we performed kinome-, transcriptome-, and proteome-profiling and discovered that RepSox inhibited TGF-ß, VEGFA, and inflammatory gene networks. In addition, RepSox not only activated vascular-stabilizing and barrier-establishing Notch and Wnt pathways, but also induced expression of important tight junctions and transporters. Taken together, our data suggest that inhibiting multiple pathways by selected individual small molecules, such as RepSox, may be an effective strategy for the development of better BRB/BBB models and novel EC barrier-inducing therapeutics.


Assuntos
Células Endoteliais/efeitos dos fármacos , Células-Tronco Pluripotentes/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematorretiniana/efeitos dos fármacos , Barreira Hematorretiniana/metabolismo , Diferenciação Celular , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Claudina-5/genética , Claudina-5/metabolismo , Avaliação Pré-Clínica de Medicamentos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Edição de Genes , Genoma , Humanos , Camundongos , Camundongos Knockout , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Pirazóis/farmacologia , Piridinas/farmacologia , Junções Íntimas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
3.
Med Sci (Paris) ; 36(6-7): 600-606, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32614311

RESUMO

In inherited retinal diseases such retinitis pigmentosa, characterized by progressive loss of light sensitive neurons (photoreceptors), cell therapy is now considered as an attractive strategy. Photoreceptor cell replacement would be valuable for restoring function to retinas in a way that is independent from the cause of the disease. With advances in stem cell biology, considerable strides have been made towards the generation of retinal cells, in particular with the development of 3D culture systems allowing the generation of retinal organoids from pluripotent stem cells. In this review, we present a state-of-the art of preclinical strategies conducted in animal models for photoreceptor replacement from stem cell-derived photoreceptors and we discuss the important obstacles to overcome in the future.


Assuntos
Células Fotorreceptoras/transplante , Retinite Pigmentosa/terapia , Terapias em Estudo/métodos , Terapias em Estudo/tendências , Animais , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/transplante , Organoides/citologia , Organoides/fisiologia , Células Fotorreceptoras/citologia , Células Fotorreceptoras/fisiologia , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/transplante , Retina/citologia , Retina/embriologia , Retina/transplante , Degeneração Retiniana/terapia , Retinite Pigmentosa/patologia , Índice de Gravidade de Doença , Técnicas de Cultura de Tecidos , Coleta de Tecidos e Órgãos/métodos , Coleta de Tecidos e Órgãos/normas , Coleta de Tecidos e Órgãos/tendências
5.
Nat Commun ; 11(1): 2713, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483127

RESUMO

Despite their rapidly-expanding therapeutic potential, human pluripotent stem cell (hPSC)-derived cell therapies continue to have serious safety risks. Transplantation of hPSC-derived cell populations into preclinical models has generated teratomas (tumors arising from undifferentiated hPSCs), unwanted tissues, and other types of adverse events. Mitigating these risks is important to increase the safety of such therapies. Here we use genome editing to engineer a general platform to improve the safety of future hPSC-derived cell transplantation therapies. Specifically, we develop hPSC lines bearing two drug-inducible safeguards, which have distinct functionalities and address separate safety concerns. In vitro administration of one small molecule depletes undifferentiated hPSCs >106-fold, thus preventing teratoma formation in vivo. Administration of a second small molecule kills all hPSC-derived cell-types, thus providing an option to eliminate the entire hPSC-derived cell product in vivo if adverse events arise. These orthogonal safety switches address major safety concerns with pluripotent cell-derived therapies.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular/genética , Edição de Genes/métodos , Células-Tronco Pluripotentes/metabolismo , Transplante de Células-Tronco/métodos , Animais , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia , Tacrolimo/análogos & derivados , Tacrolimo/farmacologia , Teratoma/genética , Teratoma/metabolismo , Teratoma/prevenção & controle
6.
Nat Commun ; 11(1): 3025, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541821

RESUMO

Approximately 10% of fractures will not heal without intervention. Current treatments can be marginally effective, costly, and some have adverse effects. A safe and manufacturable mimic of anabolic bone is the primary goal of bone engineering, but achieving this is challenging. Mesenchymal stem cells (MSCs), are excellent candidates for engineering bone, but lack reproducibility due to donor source and culture methodology. The need for a bioactive attachment substrate also hinders progress. Herein, we describe a highly osteogenic MSC line generated from induced pluripotent stem cells that generates high yields of an osteogenic cell-matrix (ihOCM) in vitro. In mice, the intrinsic osteogenic activity of ihOCM surpasses bone morphogenic protein 2 (BMP2) driving healing of calvarial defects in 4 weeks by a mechanism mediated in part by collagen VI and XII. We propose that ihOCM may represent an effective replacement for autograft and BMP products used commonly in bone tissue engineering.


Assuntos
Osteogênese , Células-Tronco Pluripotentes/citologia , Animais , Proteína Morfogenética Óssea 2/genética , Proteína Morfogenética Óssea 2/metabolismo , Proliferação de Células , Células Cultivadas , Colágeno Tipo VI/genética , Colágeno Tipo VI/metabolismo , Colágeno Tipo XII/genética , Colágeno Tipo XII/metabolismo , Anormalidades Craniofaciais/fisiopatologia , Anormalidades Craniofaciais/terapia , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Células-Tronco Pluripotentes/metabolismo , Células-Tronco Pluripotentes/transplante , Engenharia Tecidual
7.
Nat Commun ; 11(1): 2696, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483223

RESUMO

Conversion between cell types, e.g., by induced expression of master transcription factors, holds great promise for cellular therapy. Our ability to manipulate cell identity is constrained by incomplete information on cell identity genes (CIGs) and their expression regulation. Here, we develop CEFCIG, an artificial intelligent framework to uncover CIGs and further define their master regulators. On the basis of machine learning, CEFCIG reveals unique histone codes for transcriptional regulation of reported CIGs, and utilizes these codes to predict CIGs and their master regulators with high accuracy. Applying CEFCIG to 1,005 epigenetic profiles, our analysis uncovers the landscape of regulation network for identity genes in individual cell or tissue types. Together, this work provides insights into cell identity regulation, and delivers a powerful technique to facilitate regenerative medicine.


Assuntos
Células/classificação , Células/metabolismo , Código das Histonas , Aprendizado de Máquina , Algoritmos , Células/citologia , Sequenciamento de Cromatina por Imunoprecipitação/estatística & dados numéricos , Bases de Dados Genéticas/estatística & dados numéricos , Epigênese Genética , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Fenótipo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , RNA-Seq/estatística & dados numéricos , Medicina Regenerativa , Fatores de Transcrição/metabolismo
8.
J Vis Exp ; (159)2020 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-32510508

RESUMO

Human pluripotent stem cells (hPSCs) have become a powerful tool for disease modeling and the study of human embryonic development in vitro. We previously presented a differentiation protocol for the derivation of autonomic neurons with sympathetic character that has been applied to patients with autonomic neuropathy. However, the protocol was built on Knock Out Serum Replacement (KSR) and feeder-based culture conditions, and to ensure high differentiation efficiency, cell sorting was necessary. These factors cause high variability, high cost, and low reproducibility. Moreover, mature sympathetic properties, including electrical activity, have not been verified. Here, we present an optimized protocol where PSC culture and differentiation are performed in feeder-free and chemically defined culture conditions. Genetic markers identifying trunk neural crest are identified. Further differentiation into postganglionic sympathetic neurons is achieved after 20 days without the need for cell sorting. Electrophysiological recording further shows the functional neuron identity. Firing detected from our differentiated neurons can be enhanced by nicotine and suppressed by the adrenergic receptor antagonist propranolol. Intermediate sympathetic neural progenitors in this protocol can be maintained as neural spheroids for up to 2 weeks, which allows expansion of the cultures. In sum, our updated sympathetic neuron differentiation protocol shows high differentiation efficiency, better reproducibility, more flexibility, and better neural maturation compared to the previous version. This protocol will provide researchers with the cells necessary to study human disorders that affect the autonomic nervous system.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular , Meios de Cultura/química , Gânglios Parassimpáticos/citologia , Neurônios/citologia , Células-Tronco Pluripotentes/citologia , Células Cultivadas , Humanos , Reprodutibilidade dos Testes
9.
Proc Natl Acad Sci U S A ; 117(26): 15085-15095, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32546527

RESUMO

Comparative transcriptomics between differentiating human pluripotent stem cells (hPSCs) and developing mouse neurons offers a powerful approach to compare genetic and epigenetic pathways in human and mouse neurons. To analyze human Purkinje cell (PC) differentiation, we optimized a protocol to generate human pluripotent stem cell-derived Purkinje cells (hPSC-PCs) that formed synapses when cultured with mouse cerebellar glia and granule cells and fired large calcium currents, measured with the genetically encoded calcium indicator jRGECO1a. To directly compare global gene expression of hPSC-PCs with developing mouse PCs, we used translating ribosomal affinity purification (TRAP). As a first step, we used Tg(Pcp2-L10a-Egfp) TRAP mice to profile actively transcribed genes in developing postnatal mouse PCs and used metagene projection to identify the most salient patterns of PC gene expression over time. We then created a transgenic Pcp2-L10a-Egfp TRAP hPSC line to profile gene expression in differentiating hPSC-PCs, finding that the key gene expression pathways of differentiated hPSC-PCs most closely matched those of late juvenile mouse PCs (P21). Comparative bioinformatics identified classical PC gene signatures as well as novel mitochondrial and autophagy gene pathways during the differentiation of both mouse and human PCs. In addition, we identified genes expressed in hPSC-PCs but not mouse PCs and confirmed protein expression of a novel human PC gene, CD40LG, expressed in both hPSC-PCs and native human cerebellar tissue. This study therefore provides a direct comparison of hPSC-PC and mouse PC gene expression and a robust method for generating differentiated hPSC-PCs with human-specific gene expression for modeling developmental and degenerative cerebellar disorders.


Assuntos
Diferenciação Celular , Células de Purkinje/metabolismo , Transcriptoma , Animais , Humanos , Camundongos , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Proteínas/genética , Proteínas/metabolismo , Células de Purkinje/citologia
10.
Nature ; 582(7812): 399-404, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32494013

RESUMO

The skin is a multilayered organ, equipped with appendages (that is, follicles and glands), that is critical for regulating body temperature and the retention of bodily fluids, guarding against external stresses and mediating the sensation of touch and pain1,2. Reconstructing appendage-bearing skin in cultures and in bioengineered grafts is a biomedical challenge that has yet to be met3-9. Here we report an organoid culture system that generates complex skin from human pluripotent stem cells. We use stepwise modulation of the transforming growth factor ß (TGFß) and fibroblast growth factor (FGF) signalling pathways to co-induce cranial epithelial cells and neural crest cells within a spherical cell aggregate. During an incubation period of 4-5 months, we observe the emergence of a cyst-like skin organoid composed of stratified epidermis, fat-rich dermis and pigmented hair follicles that are equipped with sebaceous glands. A network of sensory neurons and Schwann cells form nerve-like bundles that target Merkel cells in organoid hair follicles, mimicking the neural circuitry associated with human touch. Single-cell RNA sequencing and direct comparison to fetal specimens suggest that the skin organoids are equivalent to the facial skin of human fetuses in the second trimester of development. Moreover, we show that skin organoids form planar hair-bearing skin when grafted onto nude mice. Together, our results demonstrate that nearly complete skin can self-assemble in vitro and be used to reconstitute skin in vivo. We anticipate that our skin organoids will provide a foundation for future studies of human skin development, disease modelling and reconstructive surgery.


Assuntos
Cabelo/citologia , Cabelo/crescimento & desenvolvimento , Organoides/citologia , Células-Tronco Pluripotentes/citologia , Pele/citologia , Animais , Ectoderma/citologia , Feminino , Cabelo/transplante , Cor de Cabelo , Folículo Piloso/citologia , Folículo Piloso/crescimento & desenvolvimento , Folículo Piloso/inervação , Folículo Piloso/transplante , Cabeça , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Organoides/crescimento & desenvolvimento , Organoides/inervação , Organoides/transplante , RNA-Seq , Análise de Célula Única , Pele/crescimento & desenvolvimento , Pele/inervação , Transplante de Pele
11.
Nat Commun ; 11(1): 2241, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382023

RESUMO

The generation of pancreatic cell types from renewable cell sources holds promise for cell replacement therapies for diabetes. Although most effort has focused on generating pancreatic beta cells, considerable evidence indicates that glucagon secreting alpha cells are critically involved in disease progression and proper glucose control. Here we report on the generation of stem cell-derived human pancreatic alpha (SC-alpha) cells from pluripotent stem cells via a transient pre-alpha cell intermediate. These pre-alpha cells exhibit a transcriptional profile similar to mature alpha cells and although they produce proinsulin protein, they do not secrete significant amounts of processed insulin. Compound screening identified a protein kinase c activator that promotes maturation of pre-alpha cells into SC-alpha cells. The resulting SC-alpha cells do not express insulin, share an ultrastructure similar to cadaveric alpha cells, express and secrete glucagon in response to glucose and some glucagon secretagogues, and elevate blood glucose upon transplantation in mice.


Assuntos
Técnicas de Cultura de Células/métodos , Células Secretoras de Glucagon/citologia , Células Secretoras de Insulina/efeitos dos fármacos , Células-Tronco Pluripotentes/citologia , Western Blotting , Diferenciação Celular/fisiologia , Linhagem Celular , Eletrofisiologia , Imunofluorescência , Humanos , Pâncreas/citologia
12.
Nat Commun ; 11(1): 2420, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415101

RESUMO

Archetypal human pluripotent stem cells (hPSC) are widely considered to be equivalent in developmental status to mouse epiblast stem cells, which correspond to pluripotent cells at a late post-implantation stage of embryogenesis. Heterogeneity within hPSC cultures complicates this interspecies comparison. Here we show that a subpopulation of archetypal hPSC enriched for high self-renewal capacity (ESR) has distinct properties relative to the bulk of the population, including a cell cycle with a very low G1 fraction and a metabolomic profile that reflects a combination of oxidative phosphorylation and glycolysis. ESR cells are pluripotent and capable of differentiation into primordial germ cell-like cells. Global DNA methylation levels in the ESR subpopulation are lower than those in mouse epiblast stem cells. Chromatin accessibility analysis revealed a unique set of open chromatin sites in ESR cells. RNA-seq at the subpopulation and single cell levels shows that, unlike mouse epiblast stem cells, the ESR subset of hPSC displays no lineage priming, and that it can be clearly distinguished from gastrulating and extraembryonic cell populations in the primate embryo. ESR hPSC correspond to an earlier stage of post-implantation development than mouse epiblast stem cells.


Assuntos
Células-Tronco Embrionárias/citologia , Camadas Germinativas/citologia , Células-Tronco Pluripotentes/citologia , Animais , Diferenciação Celular , Cromatina/metabolismo , Metilação de DNA , Epigenoma , Citometria de Fluxo , Técnica Indireta de Fluorescência para Anticorpo , Fase G1 , Camadas Germinativas/metabolismo , Glicólise , Humanos , Sistema de Sinalização das MAP Quinases , Metabolômica , Camundongos , Mitocôndrias/metabolismo , Fosforilação Oxidativa , RNA-Seq , Transdução de Sinais
13.
Nat Commun ; 11(1): 2564, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444798

RESUMO

Chromosome structure is a crucial regulatory factor for a wide range of nuclear processes. Chromosome conformation capture (3C)-based experiments combined with computational modelling are pivotal for unveiling 3D chromosome structure. Here, we introduce TADdyn, a tool that integrates time-course 3C data, restraint-based modelling, and molecular dynamics to simulate the structural rearrangements of genomic loci in a completely data-driven way. We apply TADdyn on in situ Hi-C time-course experiments studying the reprogramming of murine B cells to pluripotent cells, and characterize the structural rearrangements that take place upon changes in the transcriptional state of 21 genomic loci of diverse expression dynamics. By measuring various structural and dynamical properties, we find that during gene activation, the transcription starting site contacts with open and active regions in 3D chromatin domains. We propose that these 3D hubs of open and active chromatin may constitute a general feature to trigger and maintain gene transcription.


Assuntos
Linfócitos B/metabolismo , Reprogramação Celular , Cromatina/química , Ativação Transcricional , Animais , Linfócitos B/química , Linfócitos B/citologia , Núcleo Celular/química , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Camundongos , Células-Tronco Pluripotentes/química , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo
14.
PLoS One ; 15(5): e0233057, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32396545

RESUMO

Poor survival of human pluripotent stem cells (hPSCs) following freezing, thawing, or passaging hinders the maintenance and differentiation of stem cells. Rho-associated kinases (ROCKs) play a crucial role in hPSC survival. To date, a typical ROCK inhibitor, Y-27632, has been the primary agent used in hPSC research. Here, we report that another ROCK inhibitor, fasudil, can be used as an alternative and is cheaper than Y-27632. It increased hPSC growth following thawing and passaging, like Y-27632, and did not affect pluripotency, differentiation ability, and chromosome integrity. Furthermore, fasudil promoted retinal pigment epithelium (RPE) differentiation and the survival of neural crest cells (NCCs) during differentiation. It was also useful for single-cell passaging of hPSCs and during aggregation. These findings suggest that fasudil can replace Y-27632 for use in stem research.


Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Quinases Associadas a rho/antagonistas & inibidores , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Amidas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Crista Neural/citologia , Crista Neural/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Pesquisa com Células-Tronco
15.
J Vis Exp ; (158)2020 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-32420995

RESUMO

During mammalian development, cell fates are determined through the establishment of regulatory networks that define the specificity, timing, and spatial patterns of gene expression. Embryoid bodies (EBs) derived from pluripotent stem cells have been a popular model to study the differentiation of the main three germ layers and to define regulatory circuits during cell fate specification. Although it is well-known that tissue-specific enhancers play an important role in these networks by interacting with promoters, assigning them to their relevant target genes still remains challenging. To make this possible, quantitative approaches are needed to study enhancer-promoter contacts and their dynamics during development. Here, we adapted a 4C method to define enhancers and their contacts with cognate promoters in the EB differentiation model. The method uses frequently cutting restriction enzymes, sonication, and a nested-ligation-mediated PCR protocol compatible with commercial DNA library preparation kits. Subsequently, the 4C libraries are subjected to high-throughput sequencing and analyzed bioinformatically, allowing detection and quantification of all sequences that have contacts with a chosen promoter. The resulting sequencing data can also be used to gain information about the dynamics of enhancer-promoter contacts during differentiation. The technique described for the EB differentiation model is easy to implement.


Assuntos
Corpos Embrioides/citologia , Animais , Cromossomos , Biologia Computacional , Enzimas de Restrição do DNA , Elementos Facilitadores Genéticos , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , Células-Tronco Pluripotentes/citologia , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas
16.
Nat Cell Biol ; 22(6): 651-662, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32393886

RESUMO

BMP4 regulates a plethora of developmental processes, including the dorsal-ventral axis and neural patterning. Here, we report that BMP4 reconfigures the nuclear architecture during the primed-to-naive transition (PNT). We first established a BMP4-driven PNT and show that BMP4 orchestrates the chromatin accessibility dynamics during PNT. Among the loci opened early by BMP4, we identified Zbtb7a and Zbtb7b (Zbtb7a/b) as targets that drive PNT. ZBTB7A/B in turn facilitate the opening of naive pluripotent chromatin loci and the activation of nearby genes. Mechanistically, ZBTB7A not only binds to chromatin loci near to the genes that are activated, but also strategically occupies those that are silenced, consistent with a role of BMP4 in both activating and suppressing gene expression during PNT at the chromatin level. Our results reveal a previously unknown function of BMP4 in regulating nuclear architecture and link its targets ZBTB7A/B to chromatin remodelling and pluripotent fate control.


Assuntos
Proteína Morfogenética Óssea 4/metabolismo , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Embrionárias/citologia , Camadas Germinativas/citologia , Células-Tronco Pluripotentes/citologia , Fatores de Transcrição/metabolismo , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Proteína Morfogenética Óssea 4/genética , Diferenciação Celular , Células Cultivadas , Cromatina/genética , Proteínas de Ligação a DNA/genética , Células-Tronco Embrionárias/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Células-Tronco Pluripotentes/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética
17.
J Vis Exp ; (159)2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32449710

RESUMO

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to shortages in donor organ availability. Organ scarcity also affects the routine supply of human hepatocytes for basic research and the clinic. Therefore, the development of renewable sources of human liver progenitor cells is desirable and is the goal of this study. To be able to effectively generate and deploy human liver progenitors on a large scale, a reproducible hepatic progenitor differentiation system was developed. This protocol aids experimental reproducibility between users in a range of cell cultureware formats and permits differentiations using both, human embryonic and induced pluripotent stem cell lines. These are important advantages over current differentiation systems that will enhance the basic research and may pave the way towards clinical product development.


Assuntos
Diferenciação Celular , Fígado/citologia , Células-Tronco Pluripotentes/citologia , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Endoderma/citologia , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Processamento de Imagem Assistida por Computador , Laminina/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Reprodutibilidade dos Testes
18.
Adv Exp Med Biol ; 1236: 65-85, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32304069

RESUMO

The pancreas is a glandular organ responsible for diverse homeostatic functions, including hormone production from the endocrine islet cells to regulate blood sugar levels and enzyme secretion from the exocrine acinar cells to facilitate food digestion. These pancreatic functions are essential for life; therefore, preserving pancreatic function is of utmost importance. Pancreas dysfunction can arise either from developmental disorders or adult onset disease, both of which are caused by defects in shared molecular pathways. In this chapter, we discuss what is known about the molecular mechanisms controlling pancreas development, how disruption of these mechanisms can lead to developmental defects and disease, and how essential pancreas functions can be modeled using human pluripotent stem cells. At the core of understanding of these molecular processes are animal model studies that continue to be essential for elucidating the mechanisms underlying human pancreatic functions and diseases.


Assuntos
Modelos Animais , Organogênese , Pâncreas/embriologia , Pâncreas/patologia , Células Acinares/metabolismo , Células Acinares/patologia , Animais , Humanos , Pâncreas/citologia , Pâncreas Exócrino/citologia , Pâncreas Exócrino/embriologia , Pâncreas Exócrino/patologia , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/patologia
19.
Nature ; 580(7801): 124-129, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238941

RESUMO

Pluripotent stem cells are increasingly used to model different aspects of embryogenesis and organ formation1. Despite recent advances in in vitro induction of major mesodermal lineages and cell types2,3, experimental model systems that can recapitulate more complex features of human mesoderm development and patterning are largely missing. Here we used induced pluripotent stem cells for the stepwise in vitro induction of presomitic mesoderm and its derivatives to model distinct aspects of human somitogenesis. We focused initially on modelling the human segmentation clock, a major biological concept believed to underlie the rhythmic and controlled emergence of somites, which give rise to the segmental pattern of the vertebrate axial skeleton. We observed oscillatory expression of core segmentation clock genes, including HES7 and DKK1, determined the period of the human segmentation clock to be around five hours, and demonstrated the presence of dynamic travelling-wave-like gene expression in in vitro-induced human presomitic mesoderm. Furthermore, we identified and compared oscillatory genes in human and mouse presomitic mesoderm derived from pluripotent stem cells, which revealed species-specific and shared molecular components and pathways associated with the putative mouse and human segmentation clocks. Using CRISPR-Cas9-based genome editing technology, we then targeted genes for which mutations in patients with segmentation defects of the vertebrae, such as spondylocostal dysostosis, have been reported (HES7, LFNG, DLL3 and MESP2). Subsequent analysis of patient-like and patient-derived induced pluripotent stem cells revealed gene-specific alterations in oscillation, synchronization or differentiation properties. Our findings provide insights into the human segmentation clock as well as diseases associated with human axial skeletogenesis.


Assuntos
Relógios Biológicos/fisiologia , Desenvolvimento Embrionário/fisiologia , Células-Tronco Pluripotentes/citologia , Somitos/citologia , Somitos/crescimento & desenvolvimento , Anormalidades Múltiplas/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/deficiência , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Relógios Biológicos/genética , Desenvolvimento Embrionário/genética , Edição de Genes , Regulação da Expressão Gênica no Desenvolvimento/genética , Glicosiltransferases/deficiência , Glicosiltransferases/genética , Hérnia Diafragmática/genética , Humanos , Técnicas In Vitro , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Fenótipo , Somitos/metabolismo , Fatores de Tempo
20.
Nat Cell Biol ; 22(4): 389-400, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32231305

RESUMO

In mouse embryonic stem cells (mESCs), chemical blockade of Gsk3α/ß and Mek1/2 (2i) instructs a self-renewing ground state whose endogenous inducers are unknown. Here we show that the axon guidance cue Netrin-1 promotes naive pluripotency by triggering profound signalling, transcriptomic and epigenetic changes in mESCs. Furthermore, we demonstrate that Netrin-1 can substitute for blockade of Gsk3α/ß and Mek1/2 to sustain self-renewal of mESCs in combination with leukaemia inhibitory factor and regulates the formation of the mouse pluripotent blastocyst. Mechanistically, we reveal how Netrin-1 and the balance of its receptors Neo1 and Unc5B co-regulate Wnt and MAPK pathways in both mouse and human ESCs. Netrin-1 induces Fak kinase to inactivate Gsk3α/ß and stabilize ß-catenin while increasing the phosphatase activity of a Ppp2r2c-containing Pp2a complex to reduce Erk1/2 activity. Collectively, this work identifies Netrin-1 as a regulator of pluripotency and reveals that it mediates different effects in mESCs depending on its receptor dosage, opening perspectives for balancing self-renewal and lineage commitment.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas do Tecido Nervoso/genética , Receptores de Netrina/genética , Netrina-1/genética , Receptores de Superfície Celular/genética , Via de Sinalização Wnt/genética , Animais , Linhagem Celular , Embrião de Mamíferos , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Quinase 1 de Adesão Focal/genética , Quinase 1 de Adesão Focal/metabolismo , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Fator Inibidor de Leucemia/genética , Fator Inibidor de Leucemia/metabolismo , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/antagonistas & inibidores , MAP Quinase Quinase 2/genética , MAP Quinase Quinase 2/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos SCID , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Netrina/metabolismo , Netrina-1/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Proteína Fosfatase 2/genética , Proteína Fosfatase 2/metabolismo , Receptores de Superfície Celular/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
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