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1.
Nature ; 608(7922): 405-412, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35922506

RESUMO

After cessation of blood flow or similar ischaemic exposures, deleterious molecular cascades commence in mammalian cells, eventually leading to their death1,2. Yet with targeted interventions, these processes can be mitigated or reversed, even minutes or hours post mortem, as also reported in the isolated porcine brain using BrainEx technology3. To date, translating single-organ interventions to intact, whole-body applications remains hampered by circulatory and multisystem physiological challenges. Here we describe OrganEx, an adaptation of the BrainEx extracorporeal pulsatile-perfusion system and cytoprotective perfusate for porcine whole-body settings. After 1 h of warm ischaemia, OrganEx application preserved tissue integrity, decreased cell death and restored selected molecular and cellular processes across multiple vital organs. Commensurately, single-nucleus transcriptomic analysis revealed organ- and cell-type-specific gene expression patterns that are reflective of specific molecular and cellular repair processes. Our analysis comprises a comprehensive resource of cell-type-specific changes during defined ischaemic intervals and perfusion interventions spanning multiple organs, and it reveals an underappreciated potential for cellular recovery after prolonged whole-body warm ischaemia in a large mammal.


Assuntos
Sobrevivência Celular , Citoproteção , Perfusão , Suínos , Isquemia Quente , Animais , Morte Celular , Perfilação da Expressão Gênica , Isquemia/metabolismo , Isquemia/patologia , Isquemia/prevenção & controle , Especificidade de Órgãos , Perfusão/métodos , Suínos/anatomia & histologia
2.
Nature ; 598(7881): 483-488, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34599305

RESUMO

The prefrontal cortex (PFC) and its connections with the mediodorsal thalamus are crucial for cognitive flexibility and working memory1 and are thought to be altered in disorders such as autism2,3 and schizophrenia4,5. Although developmental mechanisms that govern the regional patterning of the cerebral cortex have been characterized in rodents6-9, the mechanisms that underlie the development of PFC-mediodorsal thalamus connectivity and the lateral expansion of the PFC with a distinct granular layer 4 in primates10,11 remain unknown. Here we report an anterior (frontal) to posterior (temporal), PFC-enriched gradient of retinoic acid, a signalling molecule that regulates neural development and function12-15, and we identify genes that are regulated by retinoic acid in the neocortex of humans and macaques at the early and middle stages of fetal development. We observed several potential sources of retinoic acid, including the expression and cortical expansion of retinoic-acid-synthesizing enzymes specifically in primates as compared to mice. Furthermore, retinoic acid signalling is largely confined to the prospective PFC by CYP26B1, a retinoic-acid-catabolizing enzyme, which is upregulated in the prospective motor cortex. Genetic deletions in mice revealed that retinoic acid signalling through the retinoic acid receptors RXRG and RARB, as well as CYP26B1-dependent catabolism, are involved in proper molecular patterning of prefrontal and motor areas, development of PFC-mediodorsal thalamus connectivity, intra-PFC dendritic spinogenesis and expression of the layer 4 marker RORB. Together, these findings show that retinoic acid signalling has a critical role in the development of the PFC and, potentially, in its evolutionary expansion.


Assuntos
Organogênese , Córtex Pré-Frontal/embriologia , Córtex Pré-Frontal/metabolismo , Tretinoína/metabolismo , Animais , Axônios/metabolismo , Córtex Cerebral , Regulação para Baixo , Feminino , Humanos , Macaca mulatta , Masculino , Camundongos , Pan troglodytes , Córtex Pré-Frontal/anatomia & histologia , Córtex Pré-Frontal/citologia , Receptores do Ácido Retinoico/deficiência , Receptor X Retinoide gama/deficiência , Transdução de Sinais , Sinapses/metabolismo , Tálamo/anatomia & histologia , Tálamo/citologia , Tálamo/metabolismo
3.
bioRxiv ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38915580

RESUMO

The implications of the early phases of human telencephalic development, involving neural stem cells (NSCs), in the etiology of cortical disorders remain elusive. Here, we explored the expression dynamics of cortical and neuropsychiatric disorder-associated genes in datasets generated from human NSCs across telencephalic fate transitions in vitro and in vivo. We identified risk genes expressed in brain organizers and sequential gene regulatory networks across corticogenesis revealing disease-specific critical phases, when NSCs are more vulnerable to gene dysfunctions, and converging signaling across multiple diseases. Moreover, we simulated the impact of risk transcription factor (TF) depletions on different neural cell types spanning the developing human neocortex and observed a spatiotemporal-dependent effect for each perturbation. Finally, single-cell transcriptomics of newly generated autism-affected patient-derived NSCs in vitro revealed recurrent alterations of TFs orchestrating brain patterning and NSC lineage commitment. This work opens new perspectives to explore human brain dysfunctions at the early phases of development.

4.
Gastroenterology ; 142(3): 602-11, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22138358

RESUMO

BACKGROUND & AIMS: Many studies of embryonic stem cells have investigated direct cell replacement of damaged tissues, but little is known about how donor cell-derived signals affect host tissue regeneration. We investigated the direct and indirect roles of human embryonic stem cell-derived cells in liver repair in mice. METHODS: To promote the initial differentiation of human embryonic stem cells into mesendoderm, we activated the ß-catenin signaling pathway with lithium; cells were then further differentiated into hepatocyte-like cells. The differentiated cells were purified by indocyanine green staining and laser microdissection and characterized by immunostaining, polymerase chain reaction, biochemical function, electron microscopy, and transplantation analyses. To investigate indirect effects of these cells, secreted proteins (secretomes) were analyzed by a label-free quantitative mass spectrometry. Carbon tetrachloride was used to induce acute liver injury in mice; cells or secreted proteins were administered by intrasplenic or intraperitoneal injection, respectively. RESULTS: The differentiated hepatocyte-like cells had multiple features of normal hepatocytes, engrafted efficiently into mice, and continued to have hepatic features; they promoted proliferation of host hepatocytes and revascularization of injured host liver tissues. Proteomic analysis identified proteins secreted from these cells that might promote host tissue repair. Injection of the secreted proteins into injured livers of mice promoted significant amounts of tissue regeneration without cell grafts. CONCLUSIONS: Hepatocyte-like cells derived from human embryonic stem cells contribute to recovery of injured liver tissues in mice, not only by cell replacement but also by delivering trophic factors that support endogenous liver regeneration.


Assuntos
Diferenciação Celular , Proliferação de Células , Doença Hepática Induzida por Substâncias e Drogas/cirurgia , Células-Tronco Embrionárias/transplante , Hepatócitos/transplante , Células-Tronco Pluripotentes Induzidas/transplante , Regeneração Hepática , Fígado/patologia , Animais , Biomarcadores/metabolismo , Tetracloreto de Carbono , Diferenciação Celular/efeitos dos fármacos , Separação Celular/métodos , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Técnicas de Cocultura , Modelos Animais de Doenças , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Imuno-Histoquímica , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Microdissecção e Captura a Laser , Cloreto de Lítio/farmacologia , Fígado/irrigação sanguínea , Fígado/metabolismo , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia Eletrônica , Neovascularização Fisiológica , Reação em Cadeia da Polimerase , Proteômica/métodos , Fatores de Tempo , Cicatrização
5.
Science ; 382(6667): eadf3786, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37824652

RESUMO

During early telencephalic development, intricate processes of regional patterning and neural stem cell (NSC) fate specification take place. However, our understanding of these processes in primates, including both conserved and species-specific features, remains limited. Here, we profiled 761,529 single-cell transcriptomes from multiple regions of the prenatal macaque telencephalon. We deciphered the molecular programs of the early organizing centers and their cross-talk with NSCs, revealing primate-biased galanin-like peptide (GALP) signaling in the anteroventral telencephalon. Regional transcriptomic variations were observed along the frontotemporal axis during early stages of neocortical NSC progression and in neurons and astrocytes. Additionally, we found that genes associated with neuropsychiatric disorders and brain cancer risk might play critical roles in the early telencephalic organizers and during NSC progression.


Assuntos
Células-Tronco Neurais , Neurogênese , Telencéfalo , Animais , Feminino , Gravidez , Macaca , Células-Tronco Neurais/citologia , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Telencéfalo/citologia , Telencéfalo/embriologia , Neurogênese/genética , Peptídeo Semelhante a Galanina/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Transtornos Mentais/genética , Doenças do Sistema Nervoso/genética , Neoplasias Encefálicas/genética
6.
Nat Neurosci ; 25(4): 458-473, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35379995

RESUMO

Hydrocephalus, characterized by cerebral ventricular dilatation, is routinely attributed to primary defects in cerebrospinal fluid (CSF) homeostasis. This fosters CSF shunting as the leading reason for brain surgery in children despite considerable disease heterogeneity. In this study, by integrating human brain transcriptomics with whole-exome sequencing of 483 patients with congenital hydrocephalus (CH), we found convergence of CH risk genes in embryonic neuroepithelial stem cells. Of all CH risk genes, TRIM71/lin-41 harbors the most de novo mutations and is most specifically expressed in neuroepithelial cells. Mice harboring neuroepithelial cell-specific Trim71 deletion or CH-specific Trim71 mutation exhibit prenatal hydrocephalus. CH mutations disrupt TRIM71 binding to its RNA targets, causing premature neuroepithelial cell differentiation and reduced neurogenesis. Cortical hypoplasia leads to a hypercompliant cortex and secondary ventricular enlargement without primary defects in CSF circulation. These data highlight the importance of precisely regulated neuroepithelial cell fate for normal brain-CSF biomechanics and support a clinically relevant neuroprogenitor-based paradigm of CH.


Assuntos
Hidrocefalia , Animais , Fenômenos Biomecânicos , Encéfalo/metabolismo , Líquido Cefalorraquidiano/metabolismo , Humanos , Hidrocefalia/líquido cefalorraquidiano , Hidrocefalia/genética , Camundongos , Neurogênese/genética , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Sequenciamento do Exoma
7.
Stem Cells ; 27(11): 2646-54, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19711444

RESUMO

In early embryonic development, spatial gradients of diffusible signaling molecules play important roles in controlling differentiation of cell types or arrays in diverse tissues. Thus, the concentration of exogenous cytokines or growth factors at any given time is crucial to the formation of an enriched population of a desired cell type from primitive stem cells in vitro. Microfluidic technology has proven very useful in the creation of cell-friendly microenvironments. Such techniques are, however, currently limited to a few cell types. Improved versatility is required if these systems are to become practically applicable to stem cells showing various plasticity ranges. Here, we built a microfluidic platform in which cells can be exposed to stable concentration gradients of various signaling molecules for more than a week with only minimal handling and no external power source. To maintain stability of the gradient concentration, the osmotic pumping performance was optimized by balancing the capillary action and hydraulic pressure in the inlet reagent reservoirs. We cultured an enriched population of neural progenitors derived from human embryonic stem cells in our microfluidic chamber for 8 days under continuous cytokine gradients (sonic hedgehog, fibroblast growth factor 8, and bone morphogenetic protein 4). Neural progenitors successfully differentiated into neurons, generating a complex neural network. The average numbers of both neuronal cell body clusters and neurite bundles were directly proportional to sonic hedgehog concentrations in the gradient chip. The system was shown to be useful for both basic and translational research, with straightforward mechanisms and operational schemes.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Citocinas/farmacologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Técnicas Analíticas Microfluídicas/métodos , Neurônios/citologia , Células-Tronco/citologia , Proteína Morfogenética Óssea 4/química , Proteína Morfogenética Óssea 4/farmacologia , Células Cultivadas , Citocinas/química , Fator 8 de Crescimento de Fibroblasto/química , Fator 8 de Crescimento de Fibroblasto/farmacologia , Citometria de Fluxo , Proteínas Hedgehog/química , Proteínas Hedgehog/farmacologia , Humanos , Imuno-Histoquímica , Modelos Teóricos , Neurônios/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos
8.
Cell Rep ; 31(5): 107599, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32375049

RESUMO

Better understanding of the progression of neural stem cells (NSCs) in the developing cerebral cortex is important for modeling neurogenesis and defining the pathogenesis of neuropsychiatric disorders. Here, we use RNA sequencing, cell imaging, and lineage tracing of mouse and human in vitro NSCs and monkey brain sections to model the generation of cortical neuronal fates. We show that conserved signaling mechanisms regulate the acute transition from proliferative NSCs to committed glutamatergic excitatory neurons. As human telencephalic NSCs develop from pluripotency in vitro, they transition through organizer states that spatially pattern the cortex before generating glutamatergic precursor fates. NSCs derived from multiple human pluripotent lines vary in these early patterning states, leading differentially to dorsal or ventral telencephalic fates. This work furthers systematic analyses of the earliest patterning events that generate the major neuronal trajectories of the human telencephalon.


Assuntos
Células-Tronco Embrionárias/metabolismo , Células-Tronco Neurais/citologia , Neurogênese/fisiologia , Neurônios/metabolismo , Diferenciação Celular/fisiologia , Células Cultivadas , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Transdução de Sinais/fisiologia
9.
Nat Commun ; 11(1): 462, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974374

RESUMO

Human induced pluripotent stem cells (hiPSCs) are a powerful model of neural differentiation and maturation. We present a hiPSC transcriptomics resource on corticogenesis from 5 iPSC donor and 13 subclonal lines across 9 time points over 5 broad conditions: self-renewal, early neuronal differentiation, neural precursor cells (NPCs), assembled rosettes, and differentiated neuronal cells. We identify widespread changes in the expression of both individual features and global patterns of transcription. We next demonstrate that co-culturing human NPCs with rodent astrocytes results in mutually synergistic maturation, and that cell type-specific expression data can be extracted using only sequencing read alignments without cell sorting. We lastly adapt a previously generated RNA deconvolution approach to single-cell expression data to estimate the relative neuronal maturity of iPSC-derived neuronal cultures and human brain tissue. Using many public datasets, we demonstrate neuronal cultures are maturationally heterogeneous but contain subsets of neurons more mature than previously observed.


Assuntos
Diferenciação Celular/genética , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Células-Tronco Neurais/fisiologia , Transcriptoma , Algoritmos , Animais , Astrócitos/citologia , Células Cultivadas , Córtex Cerebral/citologia , Técnicas de Cocultura , Bases de Dados Genéticas , Regulação da Expressão Gênica , Humanos , Modelos Neurológicos , Células-Tronco Neurais/citologia , Neurônios/citologia , Neurônios/fisiologia , Ratos
10.
Anal Chem ; 81(8): 2832-9, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19298056

RESUMO

Chromatin immunoprecipitation (ChIP) is a powerful and widely applied technique for detecting association of individual proteins with specific genomic regions; the technique requires several complex steps and is tedious. In this paper, we develop a microbead-packed microfluidic chip which eliminates most of the laborious, time-consuming, and skill-dependent processes of the ChIP procedure. A computational fluid dynamics model was established to analyze fluidic behavior in a microbead-packed microchannel. With the use of the new chip, a ChIP procedure was performed to purify the GAPDH (glyceraldehyde 3-phosphate dehydrogenase) gene from human embryonic kidney cells (cell line 293). The ChIP capability of the microfluidic chip was evaluated and compared with that of a commercial assay kit; the precipitation performance of both methods was almost identical as shown by quantitative measurement of DNA. However, our chip offers the advantage of low resin volume, and the experimental time is greatly reduced. In addition, our method is less dependent on individual technical skill. Therefore, we expect that our microfluidic chip-based ChIP method will be widely used in DNA-, gene-, and protein-related research and will improve experimental efficiency.


Assuntos
Imunoprecipitação da Cromatina/instrumentação , DNA/genética , Técnicas Analíticas Microfluídicas/métodos , Anticorpos/imunologia , Especificidade de Anticorpos , Linhagem Celular , Reagentes de Ligações Cruzadas/química , DNA/análise , DNA/isolamento & purificação , DNA/metabolismo , Proteínas de Ligação a DNA/imunologia , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/genética , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/isolamento & purificação , Histonas/análise , Histonas/metabolismo , Humanos , Modelos Químicos , Fatores de Tempo
11.
Acta Biomater ; 95: 337-347, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30529081

RESUMO

Bioengineering approaches to regulate stem cell fates aim to recapitulate the in vivo microenvironment. In recent years, manipulating the micro- and nano-scale topography of the stem cell niche has gained considerable interest for the purposes of controlling extrinsic mechanical cues to regulate stem cell fate and behavior in vitro. Here, we established an optimal nanotopographical system to improve 3-dimensional (3D) differentiation of pancreatic cells from human pluripotent stem cells (hPSCs) by testing gradient-pattern chips of nano-scale polystyrene surface structures with varying sizes and shapes. The optimal conditions for 3D differentiation of pancreatic cells were identified by assessing the expression of developmental regulators that are required for pancreatic islet development and maturation. Our results showed that the gradient chip of pore-part 2 (Po-2, 200-300 nm diameter) pattern was the most efficient setting to generate clusters of pancreatic endocrine progenitors (PDX1+ and NGN3+) compared to those of other pore diameters (Po-1, 100-200 or Po-3, 300-400 nm) tested across a range of pillar patterns and flat surfaces. Furthermore, the Po-2 gradient pattern-derived clusters generated islet-like 3D spheroids and tested positive for the zinc-chelating dye dithizone. The spheroids consisted of more than 30% CD200 + endocrine cells and also expressed NKX6.1 and NKX2.2. In addition, pancreatic ß- cells expressing insulin and polyhormonal cells expressing both insulin and glucagon were obtained at the final stage of pancreatic differentiation. In conclusion, our data suggest that an optimal topographical structure for differentiation to specific cell types from hPSCs can be tested efficiently by using gradient-pattern chips designed with varying sizes and surfaces. STATEMENT OF SIGNIFICANCE: Our study provides demonstrates of using gradient nanopatterned chips for differentiation of pancreatic islet-like clusters. Gradient nanopatterned chips are consisted of two different shapes (nanopillar and nanopore) in three different ranges of nano sizes (100-200, 200-300, 300-400 nm). We found that optimal nanostructures for differentiation of pancreatic islet-like clusters were 200-300 nm nano pores. Cell transplantation is one of the major therapeutic option for type 1 diabetes mellitus (DM) using stem cell-derived ß-like cells. We generated 50 um pancreatic islet-like clusters in size, which would be an optimal size for cell transplantation. Futuremore, the small clusters provide a powerful source for cell therapy. Our findings suggest gradient nanopatterned chip provides a powerful tool to generate specific functional cell types of a high purity for potential uses in cell therapy development.


Assuntos
Ilhotas Pancreáticas/citologia , Nanopartículas/química , Células-Tronco Pluripotentes/citologia , Agregação Celular , Diferenciação Celular , Endoderma/citologia , Proteína Homeobox Nkx-2.2 , Proteínas de Homeodomínio , Células-Tronco Embrionárias Humanas/citologia , Humanos , Proteínas Nucleares , Poliestirenos/química , Esferoides Celulares/citologia , Fatores de Transcrição
12.
Int J Hyperthermia ; 24(8): 638-48, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19065344

RESUMO

Hyperthermia, the procedure of raising the temperature of tumor-loaded tissue to 40 degrees -43 degrees C, has been applied to various established cancer treatments. Although the mechanism of hyperthermia in cancer treatment is well-known, there are few or no studies regarding the effect of hyperthermia on the tumor-supportive stroma. Mesenchymal stem cells (MSCs) display the potential for differentiation into various tissues. MSCs are also reported to play a role as potential precursors for tumor stroma in providing a favorable environment for tumor progression. Here, we investigated the effects of hyperthermia-treated MSCs on the viability and growth of cancer cells. Culture supernatants from non-shocked or heat-shocked MSCs (NS-MSCs or HS-MSCs) were added to MCF7 cells. Morphological analysis and cell proliferation assay showed the reduced viability and growth of MCF7 cells by addition of culture medium conditioned by HS-MSCs. Additionally, exposure to the conditioned medium by HS-MSCs induced cell cycle arrest at G2/M phase, increased MHC class I, Fas receptor, and TNF-R expressions, and decreased MDR1 expression in the MCF7 cells. In particular, the conditioned medium of HS-MSCs accelerated the inhibition of tumor cell growth by several chemotherapeutic drugs. These data present new aspects of hyperthermia in cancer treatment, suggesting that hyperthermia can enable tumor stroma provide a sensitizing environment for tumor cells to undergo cell death.


Assuntos
Morte Celular , Hipertermia Induzida , Células-Tronco Mesenquimais/fisiologia , Animais , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Meios de Cultivo Condicionados , Temperatura Alta , Humanos , Imunofenotipagem , Células-Tronco Mesenquimais/citologia , Proteínas de Neoplasias/metabolismo
13.
Sci Data ; 5: 180220, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30398471

RESUMO

Sarcophaga peregrina (flesh fly) is a frequently found fly species in Palaearctic, Oriental, and Australasian regions that can be used to estimate minimal postmortem intervals important for forensic investigations. Despite its forensic importance, the genome information of S. peregrina has not been fully described. Therefore, we generated a comprehensive gene expression dataset using RNA sequencing and carried out de novo assembly to characterize the S. peregrina transcriptome. We obtained precise sequence information for RNA transcripts using two different methods. Based on primary sequence information, we identified sets of assembled unigenes and predicted coding sequences. Functional annotation of the aligned unigenes was performed using the UniProt, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes databases. As a result, 26,580,352 and 83,221 raw reads were obtained using the Illumina MiSeq and Pacbio RS II Iso-Seq sequencing applications, respectively. From these reads, 55,730 contigs were successfully annotated. The present study provides the resulting genome information of S. peregrina, which is valuable for forensic applications.


Assuntos
Sarcofagídeos/genética , Transcriptoma , Animais , Genética Forense , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Anotação de Sequência Molecular , Análise de Sequência de RNA
14.
Mol Cells ; 23(1): 49-56, 2007 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-17464211

RESUMO

One of the goals of stem cell technology is to control the differentiation of human embryonic stem cells (hESCs), thereby generating large numbers of specific cell types for many applications including cell replacement therapy. Although individual hESC lines resemble each other in expressing pluripotency markers and telomerase activity, it is not clear whether they are equivalent in their developmental potential in vitro. We compared the developmental competence of three hESC lines (HSF6, Miz-hES4, and Miz-hES6). All three generated the three embryonic germ layers, extraembryonic tissues, and primordial germ cells during embryoid body (EB) formation. However, HSF6 and Miz-hES6 readily formed neuroectoderm, whereas Miz-hES4 differentiated preferentially into mesoderm and endoderm. Upon terminal differentiation, HSF6 and Miz-hES6 produced mainly neuronal cells whereas Miz-hES4 mainly formed mesendodermal derivatives, including endothelial cells, leukocyte progenitors, hepatocytes, and pancreatic cells. Our observations suggest that independently-derived hESCs may differ in their developmental potential.


Assuntos
Células-Tronco Embrionárias/citologia , Biomarcadores/metabolismo , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , Ectoderma/citologia , Células-Tronco Embrionárias/metabolismo , Endoderma/citologia , Regulação da Expressão Gênica , Humanos , Mesoderma/citologia , Células-Tronco Pluripotentes/citologia
15.
FEBS Lett ; 580(25): 5869-74, 2006 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-17027979

RESUMO

Vascular endothelial growth factor (VEGF), a potent mitogen for vascular endothelial cells, has been suggested as a modulator that is involved in neurogenesis as well as angiogenesis. Here, we directly examined the effect of VEGF on neuroectodermal differentiation using human embryonic stem cells (hESCs). VEGF treatment upregulated the expression of neuroectodermal genes (Sox1 and Nestin) during germ layer formation in embryoid bodies (EBs) and efficiently increased the number of neural rosettes expressing both Pax6 and Nestin. The neural progenitors generated from VEGF-treated EBs further differentiated into cells that showed a similar pattern of gene expression observed in the development of dopaminergic neurons upon terminal differentiation. These results support the neurogenic effect of VEGF on hESC differentiation.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/farmacologia , Sequência de Bases , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Gástrula/citologia , Gástrula/efeitos dos fármacos , Gástrula/metabolismo , Humanos , Mitógenos/farmacologia , Sistema Nervoso/citologia , Sistema Nervoso/embriologia , Sistema Nervoso/metabolismo , Neurônios/metabolismo , RNA/genética , RNA/metabolismo
16.
Toxicol Sci ; 94(2): 310-21, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16984955

RESUMO

Human embryonic stem (hES) cells have been proposed as a source of various cell types for cell replacement therapy. Besides their potential in therapeutic uses, ES cells also have other potential applications, such as in drug discovery and in vitro screening assays of various toxicants. Nonylphenol (NP) and octylphenol (OP) are common environmental contaminants, known to disrupt the reproductive and endocrine system. However, little is known about their toxicological effects on early embryonic development in humans. In this study, we used undifferentiated hES cells and the neural progenitor cells derived from them to investigate the potential toxicity of NP and OP. Our results show that the cytotoxic effects of NP and OP involve DNA fragmentation, the major characteristic of apoptosis. The NP- and OP-induced apoptosis was concomitant with the increased activity of Caspase-8 and -3. Moreover, both Fas and Fas ligand (FasL) protein expressions were markedly increased in the NP- or OP-exposed hES cells. These results suggest that NP and OP are able to trigger apoptosis in hES cells via a pathway dependent on caspase activation and Fas-FasL interaction. In particular, hES cell-derived neural progenitor cells had a higher sensitivity to the toxicants than undifferentiated hES cells, thereby suggesting that the toxic stress response may differ depending on the developmental stage. These findings offer new perspectives for understanding the fundamental mechanisms in chemical-induced apoptosis in hES cells.


Assuntos
Apoptose/efeitos dos fármacos , Células-Tronco Embrionárias/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Proteína Ligante Fas/metabolismo , Fenóis/toxicidade , Receptor fas/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/patologia , Proteína Ligante Fas/genética , Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor fas/genética
17.
Cell Transplant ; 24(10): 2155-68, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25397866

RESUMO

We previously reported the in vitro differentiation of human embryonic stem cells (hESCs) into pancreatic endoderm. Here we demonstrate that islet-like three-dimensional (3D) aggregates can be derived from the pancreatic endoderm by optimizing our previous protocol. Sequential treatment with Wnt3a, activin A, and noggin induced a transient upregulation of T and MixL1, followed by increased expression of endodermal genes, including FOXA2, SOX17, and CXCR4. Subsequent treatment with retinoic acid highly upregulated PDX1 expression. We also show that inhibition of sonic hedgehog signaling by bFGF/activin ßB and cotreatment with VEGF and FGF7 produced many 3D cellular clusters that express both SOX17 and PDX1. We found for the first time that proteoglycans and vimentin(+) mesenchymal cells were mainly localized in hESC-derived PDX1(+) clusters. Importantly, treatment with chlorate, an inhibitor of proteoglycan sulfation, together with inhibition of Notch signaling significantly increased the expression of Neurog3 and NeuroD1, promoting a transition from PDX1(+) progenitor cells toward mature pancreatic endocrine cells. Purified dithizone(+) 3D aggregates generated by our refined protocol produced pancreatic hormones and released insulin in response to both glucose and pharmacological drugs in vitro. Furthermore, the islet-like 3D aggregates decreased blood glucose levels and continued to exhibit pancreatic features after transplantation into diabetic mice. Generation of islet-like 3D cell aggregates from human pluripotent stem cells may overcome the shortage of cadaveric donor islets for future cases of clinical islet transplantation.


Assuntos
Diabetes Mellitus Experimental/terapia , Endoderma/citologia , Células-Tronco Embrionárias Humanas/citologia , Hiperglicemia/terapia , Ilhotas Pancreáticas/citologia , Animais , Técnicas de Cultura de Células , Diferenciação Celular/imunologia , Diferenciação Celular/fisiologia , Linhagem Celular , Células-Tronco Embrionárias Humanas/efeitos dos fármacos , Células-Tronco Embrionárias Humanas/transplante , Humanos , Hiperglicemia/imunologia , Camundongos , Estreptozocina
18.
Curr Biol ; 22(18): 1705-10, 2012 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-22902753

RESUMO

Sox2 is an important transcriptional regulator in embryonic and adult stem cells. Recently, Sox2 was identified as an oncogene in many endodermal cancers, including colon cancer. There is great interest in how Sox2 cooperates with other transcription factors to regulate stem cell renewal, differentiation, and reprogramming. However, we still lack a general understanding of Sox2 transcriptional action. To determine transcriptional partners of Sox2 in adult cells, we generated mice where gene expression could be induced by an externally applied stimulus. We analyzed the consequences in the intestine where cell turnover is rapid. Sox2 expression, but not Oct4, specifically increased the numbers of stem cells and repressed Cdx2, a master regulator of endodermal identity. In vivo studies demonstrated that Sox21, another member of the SoxB gene family, was a specific, immediate, and cell-autonomous target of Sox2 in intestinal stem cells. In vitro experiments showed that Sox21 was sufficient to repress Cdx2 in colon cancer cells and in pluripotent stem cells. Sox21 was also specifically induced by Sox2 in fibroblasts and inhibition of Sox21 blocked reprogramming to the pluripotent state. These results show that transcriptional induction of Sox21 is a rapid and general mediator of the effects of Sox2 on cell identity in a wide range of cell types.


Assuntos
Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição SOXB2/metabolismo , Ativação Transcricional , Animais , Fator de Transcrição CDX2 , Diferenciação Celular/genética , Linhagem Celular , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Proteínas de Homeodomínio/antagonistas & inibidores , Mucosa Intestinal/metabolismo , Intestinos/citologia , Camundongos , Camundongos Transgênicos , Fator 3 de Transcrição de Octâmero/biossíntese , Células-Tronco Pluripotentes/citologia , Fatores de Transcrição SOXB2/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Transcrição Gênica
19.
Mol Cells ; 31(2): 123-32, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21347709

RESUMO

The mammalian reproductive tract is known to contain 1.5-5.3% oxygen (O(2)), but human embryonic stem cells (hESCs) derived from preimplantation embryos are typically cultured under 21% O(2) tension. The aim of this study was to investigate the effects of O(2) tension on the long-term culture of hESCs and on cell-fate determination during early differentiation. hESCs and embryoid bodies (EBs) were grown under different O(2) tensions (3, 12, and 21% O(2)). The expression of markers associated with pluripotency, embryonic germ layers, and hypoxia was analyzed using RTPCR, immunostaining, and Western blotting. Proliferation, apoptosis, and chromosomal aberrations were examined using BrdU incorporation, caspase-3 immunostaining, and karyotype analysis, respectively. Structural and morphological changes of EBs under different O(2) tensions were comparatively examined using azan- and hematoxylineosin staining, and scanning and transmission electron microscopy. Mild hypoxia (12% O(2)) increased the number of cells expressing Oct4/Nanog and reduced BrdU incorporation and aneuploidy. The percentage of cells positive for active caspase-3, which was high during normoxia (21% O(2)), gradually decreased when hESCs were continuously cultured under mild hypoxia. EBs subjected to hypoxia (3% O(2)) exhibited well-differentiated microvilli on their surface, secreted high levels of collagen, and showed enhanced differentiation into primitive endoderm. These changes were associated with increased expression of Foxa2, Sox17, AFP, and GATA4 on the EB periphery. Our data suggest that mild hypoxia facilitates the slow mitotic division of hESCs in long-term culture and reduces the frequency of chromosomal abnormalities and apoptosis. In addition, hypoxia promotes the differentiation of EBs into extraembryonic endoderm.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular , Forma Celular , Corpos Embrioides/citologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Aberrações Cromossômicas/embriologia , Corpos Embrioides/efeitos dos fármacos , Corpos Embrioides/metabolismo , Corpos Embrioides/ultraestrutura , Células-Tronco Embrionárias/efeitos dos fármacos , Camadas Germinativas/embriologia , Humanos , Camundongos , Oxigênio/farmacologia , Fatores de Tempo
20.
FEBS Lett ; 583(3): 561-7, 2009 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-19162023

RESUMO

We demonstrate enhanced differentiation of oligodendrocytes during neurogenesis of human embryonic stem cells (hESCs) using an extracellular matrix protein, vitronectin (VN). We show that VN is expressed in the ventral part of the developing human spinal cord. Combined treatment of retinoic acid, sonic hedgehog, and noggin in the presence of VN allows hESCs to differentiate into O4-positive oligodendrocytes. Particularly, VN profoundly promotes the derivation of oligodendrocyte progenitors that proliferate and differentiate into oligodendrocytes in response to mitogenic and survival factors. These results support the beneficial effect of VN on oligodendrocytic differentiation of hESCs.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Neurogênese , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Vitronectina/metabolismo , Biomarcadores/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular , Proliferação de Células , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Medula Espinal/metabolismo
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