RESUMEN
The design of mesoporous silica nanoparticles (MSNs) for drug delivery is attracting increasing interest. Controlled release of their cargo is usually mediated by diffusion and erosion mechanisms, which might not reach the expected therapeutic effects. Here, we report the development and characterization of MSNs which modulate the cargo release in different cell models: fibroblasts and embryonic stem cells. Based on a double strategy: the presence of multimodal pore channels and a chitosan coating, we demonstrated a modulated release. Our results show that MSNs could be used for controlled drug delivery in different cell types, showing the potential of improving pluripotent stem cells differentiation and reprogramming protocols with promising applications in biomedicine.
Asunto(s)
Nanopartículas , Dióxido de Silicio , Portadores de Fármacos , Sistemas de Liberación de Medicamentos/métodos , Células Madre Embrionarias , Nanopartículas/uso terapéutico , PorosidadRESUMEN
In embryonic stem (ES) cells, oxidative stress control is crucial for genomic stability, self-renewal, and cell differentiation. Heme oxygenase-1 (HO-1) is a key player of the antioxidant system and is also involved in stem cell differentiation and pluripotency acquisition. We found that the HO-1 gene is expressed in ES cells and induced after promoting differentiation. Moreover, downregulation of the pluripotency transcription factor (TF) OCT4 increased HO-1 mRNA levels in ES cells, and analysis of ChIP-seq public data revealed that this TF binds to the HO-1 gene locus in pluripotent cells. Finally, ectopic expression of OCT4 in heterologous systems repressed a reporter carrying the HO-1 gene promoter and the endogenous gene. Hence, this work highlights the connection between pluripotency and redox homeostasis.
Asunto(s)
Regulación de la Expresión Génica , Hemo-Oxigenasa 1/genética , Proteínas de la Membrana/genética , Células Madre Embrionarias de Ratones/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/genética , Células Madre Pluripotentes/metabolismo , ARN Mensajero/genética , Animales , Benzamidas/farmacología , Diferenciación Celular/efectos de los fármacos , Difenilamina/análogos & derivados , Difenilamina/farmacología , Embrión de Mamíferos , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Hemo-Oxigenasa 1/metabolismo , Luciferasas/genética , Luciferasas/metabolismo , Proteínas de la Membrana/metabolismo , Ratones , Células Madre Embrionarias de Ratones/citología , Células Madre Embrionarias de Ratones/efectos de los fármacos , Células 3T3 NIH , Proteína Homeótica Nanog/antagonistas & inhibidores , Proteína Homeótica Nanog/genética , Proteína Homeótica Nanog/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/antagonistas & inhibidores , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Células Madre Pluripotentes/citología , Células Madre Pluripotentes/efectos de los fármacos , Regiones Promotoras Genéticas , Piridinas/farmacología , Pirimidinas/farmacología , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Factores de Transcripción SOXB1/antagonistas & inhibidores , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Transducción de Señal , Transcripción GenéticaRESUMEN
Stem cells genome safeguarding requires strict oxidative stress control. Heme oxygenase-1 (HO-1) and p53 are relevant components of the cellular defense system. p53 controls cellular response to multiple types of harmful stimulus, including oxidative stress. Otherwise, besides having a protective role, HO-1 is also involved in embryo development and in embryonic stem (ES) cells differentiation. Although both proteins have been extensively studied, little is known about their relationship in stem cells. The aim of this work is to explore HO-1-p53 interplay in ES cells. We studied HO-1 expression in p53 knockout (KO) ES cells and we found that they have higher HO-1 protein levels but similar HO-1 mRNA levels than the wild type (WT) ES cell line. Furthermore, cycloheximide treatment increased HO-1 abundance in p53 KO cells suggesting that p53 modulates HO-1 protein stability. Notably, H2O2 treatment did not induce HO-1 expression in p53 KO ES cells. Finally, SOD2 protein levels are also increased while Sod2 transcripts are not in KO cells, further suggesting that the p53 null phenotype is associated with a reinforcement of the antioxidant machinery. Our results demonstrate the existence of a connection between p53 and HO-1 in ES cells, highlighting the relationship between these stress defense pathways.
Asunto(s)
Hemo-Oxigenasa 1/fisiología , Células Madre Embrionarias Humanas , Proteína p53 Supresora de Tumor/fisiología , Diferenciación Celular , Línea Celular , Regulación del Desarrollo de la Expresión Génica , Técnicas de Inactivación de Genes , Hemo-Oxigenasa 1/genética , Células Madre Embrionarias Humanas/citología , Células Madre Embrionarias Humanas/metabolismo , Humanos , Estrés Oxidativo , Transducción de Señal , Superóxido Dismutasa/metabolismoRESUMEN
Induced pluripotent stem cells (iPSC) have a great potential, but their clinical application depends on finding strategies to abolish their tumorigenic potential. The use of Oct4, Sox2, Klf4, c-Myc and Nanog to generate iPSC demonstrated the already known importance of these genes to maintain stemness. Therefore, the presence of these genes is responsible for iPSC-derived teratomas. Similar to iPSC, P19 teratocarcinoma cell line also has characteristics of embryonic carcinoma cells and the ability to differentiate into many cell types. We separately silenced the transcription factors Oct4, Sox2, Klf4, c-Myc and Nanog in P19 cells and measured the impact of this silencing in vivo. All silenced cells generated tumors when injected in immunosuppressed mice, but silencing of Oct4, Sox2 and Klf4 generated mainly teratomas with mesoderm tissue. Our results suggest that downregulation of these transcription factors is not enough to avoid the formation of teratomas, but their silencing affect their differentiation potential.
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Silenciador del Gen , Teratoma/genética , Factores de Transcripción/genética , Animales , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular , Proliferación Celular , Femenino , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteína Homeótica Nanog/genética , Factor 3 de Transcripción de Unión a Octámeros/genética , Proteínas Proto-Oncogénicas c-myc/genética , Factores de Transcripción SOXB1/genética , Teratoma/patologíaRESUMEN
OBJECTIVE: Redox homeostasis maintenance is essential to bring about cellular functions. Particularly, embryonic stem cells (ESCs) have high fidelity mechanisms for DNA repair, high activity of different antioxidant enzymes and low levels of oxidative stress. Although the expression and activity of antioxidant enzymes are reduced throughout the differentiation, the knowledge about the transcriptional regulation of genes involved in defense against oxidative stress is yet restricted. Since glutathione is a central component of a complex system involved in preserving cellular redox status, we aimed to study whether the expression of the glutathione reductase (Gsr) gene, which encodes an essential enzyme for cellular redox homeostasis, is modulated by the transcription factors critical for self-renewal and pluripotency of ESCs. RESULTS: We found that Gsr gene is expressed in ESCs during the pluripotent state and it was upregulated when these cells were induced to differentiate, concomitantly with Nanog decreased expression. Moreover, we found an increase in Gsr mRNA levels when Nanog was downregulated by a specific shRNA targeting this transcription factor in ESCs. Our results suggest that Nanog represses Gsr gene expression in ESCs, evidencing a role of this crucial pluripotency transcription factor in preservation of redox homeostasis in stem cells.
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Glutatión Reductasa/genética , Células Madre Embrionarias de Ratones/metabolismo , Proteína Homeótica Nanog/genética , Células Madre Pluripotentes/metabolismo , Animales , Diferenciación Celular , Línea Celular , Regulación de la Expresión Génica , Genes Reporteros , Glutatión Reductasa/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Ratones , Células Madre Embrionarias de Ratones/citología , Proteína Homeótica Nanog/antagonistas & inhibidores , Proteína Homeótica Nanog/metabolismo , Células Madre Pluripotentes/citología , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Transducción de SeñalRESUMEN
Chromatin remodeling is fundamental for the dynamical changes in transcriptional programs that occur during development and stem cell differentiation. The histone acetyltransferase Kat6b is relevant for neurogenesis in mouse embryos, and mutations of this gene cause intellectual disability in humans. However, the molecular mechanisms involved in Kat6b mutant phenotype and the role of this chromatin modifier in embryonic stem (ES) cells remain elusive. In this work, we show that Kat6b is expressed in ES cells and is repressed during differentiation. Moreover, we found that this gene is regulated by the pluripotency transcription factors Nanog and Oct4. To study the functional relevance of Kat6b in ES cells, we generated a Kat6b knockout ES cell line (K6b-/-) using CRISPR/Cas9. Fluorescence correlation spectroscopy analyses suggest a more compact chromatin organization in K6b-/- cells and impaired interactions of Oct4 and Nanog with chromatin. Remarkably, K6b-/- cells showed a reduced efficiency to differentiate to neural lineage. These results reveal a role of Kat6b as a modulator of chromatin plasticity, its impact on chromatin-transcription factors interactions and its influence on cell fate decisions during neural development.
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Cromatina/metabolismo , Células Madre Embrionarias/citología , Histona Acetiltransferasas/metabolismo , Proteína Homeótica Nanog/metabolismo , Neurogénesis , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Animales , Sistemas CRISPR-Cas , Células Madre Embrionarias/metabolismo , Regulación de la Expresión Génica , Histona Acetiltransferasas/genética , Masculino , Ratones DesnudosRESUMEN
Mesenchymal stem/stromal cells (MSCs) obtained from pluripotent stem cells (PSCs) constitute an interesting alternative to classical MSCs in regenerative medicine. Among their many mechanisms of action, MSC extracellular vesicles (EVs) are a potential suitable substitute for MSCs in future cell-free-based therapeutic approaches. Unlike cells, EVs do not elicit acute immune rejection, and they can be produced in large quantities and stored until ready to use. Although the therapeutic potential of MSC EVs has already been proven, a thorough characterization of MSC EVs is lacking. In this work, we used a label-free liquid chromatography tandem mass spectrometry proteomic approach to identify the most abundant proteins in EVs that are secreted from MSCs derived from PSCs (PD-MSCs) and from their parental induced PSCs (iPSCs). Next, we compared both datasets and found that while iPSC EVs enclose proteins that modulate RNA and microRNA stability and protein sorting, PD-MSC EVs are rich in proteins that organize extracellular matrix, regulate locomotion, and influence cell-substrate adhesion. Moreover, compared to their respective cells, iPSCs and iPSC EVs share a greater proportion of proteins, while the PD-MSC proteome appears to be more specific. Correlation and principal component analysis consistently aggregate iPSCs and iPSC EVs but segregate PD-MSC and their EVs. Altogether, these findings suggest that during differentiation, compared with their parental iPSC EVs, PD-MSC EVs acquire a more specific set of proteins; arguably, this difference might confer their therapeutic properties.
Asunto(s)
Diferenciación Celular , Vesículas Extracelulares/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Madre Pluripotentes/citología , Células Madre Pluripotentes/metabolismo , Proteómica , Línea Celular , Vesículas Extracelulares/ultraestructura , Humanos , Análisis de Componente Principal , Células del Estroma/metabolismo , Espectrometría de Masas en Tándem , Gelatina de Wharton/citologíaRESUMEN
Redox homeostasis is vital for cellular functions and to prevent the detrimental consequences of oxidative stress. Pluripotent stem cells (PSCs) have an enhanced antioxidant system which supports the preservation of their genome. Besides, reactive oxygen species (ROS) are proposed to be involved in both self-renewal maintenance and in differentiation in embryonic stem cells (ESCs). Increasing evidence shows that cellular systems related to the oxidative stress defense decline along differentiation of PSCs. Although redox homeostasis has been extensively studied for many years, the knowledge about the transcriptional regulation of the genes involved in these systems is still limited. In this work, we studied Sod1 gene modulation by the PSCs fundamental transcription factors Oct4, Sox2 and Nanog. We found that this gene, which is expressed in mouse ESCs (mESCs), was repressed when they were induced to differentiate. Accordingly, these factors induced Sod1 promoter activity in a trans-activation assay. Finally, Sod1 mRNA levels were reduced when Oct4, Sox2 and Nanog were down-regulated by a shRNA approach in mESCs. Taken together, we found that PSCs' key transcription factors are involved in the modulation of Sod1 gene, suggesting a relationship between the pluripotency core and redox homeostasis in these cells.
Asunto(s)
Células Madre Embrionarias/metabolismo , Proteína Homeótica Nanog/genética , Factor 3 de Transcripción de Unión a Octámeros/genética , Factores de Transcripción SOXB1/genética , Superóxido Dismutasa-1/genética , Animales , Diferenciación Celular/genética , Células Cultivadas , Regulación hacia Abajo , Células Madre Embrionarias/enzimología , Homeostasis/genética , Ratones , Células 3T3 NIH , Proteína Homeótica Nanog/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Oxidación-Reducción , Estrés Oxidativo/genética , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/metabolismo , Factores de Transcripción SOXB1/metabolismo , Superóxido Dismutasa-1/biosíntesis , Transcripción Genética , Activación TranscripcionalRESUMEN
The cell cycle has gained attention as a key determinant for cell fate decisions, but the contribution of DNA replication and mitosis in stem cell differentiation has not been extensively studied. To understand if these processes act as "windows of opportunity" for changes in cell identity, we established synchronized cultures of mouse embryonic stem cells as they exit the ground state of pluripotency. We show that initial transcriptional changes in this transition do not require passage through mitosis and that conversion to primed pluripotency is linked to lineage priming in the G1 phase. Importantly, we demonstrate that impairment of DNA replication severely blocks transcriptional switch to primed pluripotency, even in the absence of p53 activity induced by the DNA damage response. Our data suggest an important role for DNA replication during mouse embryonic stem cell differentiation, which could shed light on why pluripotent cells are only receptive to differentiation signals during G1, that is, before the S phase.
Asunto(s)
Diferenciación Celular , División Celular , Replicación del ADN , Células Madre Embrionarias de Ratones/fisiología , Células Madre Pluripotentes/fisiología , Animales , Ratones , Transcripción GenéticaRESUMEN
Human foreskin fibroblasts were used to generate the iPSC line iPSC-FH2.1 using the EF1a-hSTEMCCA-loxP vector expressing OCT4, SOX2, c-MYC and KLF4, in 5% O2 culture conditions. Stemness was confirmed, as was pluripotency both in vivo and in vitro, in normoxia and hypoxia. Human Embryonic Stem Cell (hESC) line WA-09 and reprogrammed fibroblast primary culture HFF-FM were used as controls.
Asunto(s)
Fibroblastos/citología , Prepucio/citología , Células Madre Pluripotentes Inducidas/citología , Diferenciación Celular , Células Cultivadas , Reprogramación Celular , Hibridación Genómica Comparativa , Metilación de ADN , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Cariotipo , Factor 4 Similar a Kruppel , Masculino , Microscopía Fluorescente , Factor 3 de Transcripción de Unión a Octámeros/genética , Regiones Promotoras Genéticas , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Addition of methyl groups to arginine residues is catalyzed by a group of enzymes called Protein Arginine Methyltransferases (Prmt). Although Prmt1 is essential in development, its paralogue Prmt8 has been poorly studied. This gene was reported to be expressed in nervous system and involved in neurogenesis. In this work, we found that Prmt8 is expressed in mouse embryonic stem cells (ESC) and in induced pluripotent stem cells, and modulated along differentiation to neural precursor cells. We found that Prmt8 promoter activity is induced by the pluripotency transcription factors Oct4, Sox2 and Nanog. Moreover, endogenous Prmt8 mRNA levels were reduced in ESC transfected with Sox2 shRNA vector. As a whole, our results indicate that Prmt8 is expressed in pluripotent stem cells and its transcription is modulated by pluripotency transcription factors. These findings suggest that besides its known function in nervous system, Prmt8 could play a role in pluripotent stem cells.
Asunto(s)
Regulación Enzimológica de la Expresión Génica , Células Madre Pluripotentes/citología , Proteína-Arginina N-Metiltransferasas/metabolismo , Factores de Transcripción SOXB1/metabolismo , Animales , Diferenciación Celular , Regulación hacia Abajo , Fibroblastos/metabolismo , Proteínas de Homeodominio/metabolismo , Ratones , Células 3T3 NIH , Proteína Homeótica Nanog , Neuronas/citología , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Regiones Promotoras Genéticas , ARN Interferente Pequeño/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , TransfecciónRESUMEN
Objetivo: Determinar el riesgo de adquirir síndrome metabólico (SM) según los años de edad y otros factores asociados en trabajadores de una minera de la serranía peruana. Metodología: Estudio analítico longitudinal, de los datos obtenidos entre 2007 y 2010 en trabajadores de un campamento minero. Se consideró que los trabajadores tenían SM si cumplían los criterios de la Federación Internacional de Diabetes (diámetro de cintura ≥ 94 cm en hombres o ≥ 80 cm en mujeres, más ≥ 2 parámetros alterados: glucemia, presión arterial, colesterol HDL o triglicéridos). Se obtuvo los riesgos relativos ajustados con la regresión PAGEE, para determinar el riesgo de adquirir el SM en el tiempo (según el año del examen médico-ocupacional). Resultados: De las 1.198 mediciones de los trabajadores, el 93%(1109) fueron hombres, la mediana de edad fue de 33 años. El 36% (428) tuvo el parámetro de cintura alterado, y de ellos el 100% tuvo entre 2 o más parámetros adicionales alterados para el diagnóstico de SM. Al realizar la estadística multivariada, ajustada por el tiempo y el valor del índice de masa corporal, se encontró que por cada año de edad que aumentaban los trabajadores se incrementaba en un 2% (intervalo de confianza del 95%: 1-4%) el riesgo de tener SM. Discusión: En los trabajadores evaluados, la edad fue un factor de riesgo para presentar SM; este parámetro y otros de relevancia deben ser vigilados por las empresas para generar las políticas de estilo de vida saludable, que prevengan problemas de enfermedades crónicas con potenciales repercusiones en los trabajadores, la empresa y la sociedad.
Objective: To determine the risk of getting metabolic syndrome (MS) according to years old and others associated factors in workers mining of the Peruvian highlands. Methodology: Longitudinal study of data collected between 2007-2010 in a mining camp workers. It was considered that workers had MS if they met the criteria of the International Diabetes Federation (≥94 cm waist circumference in men or women ≥80 cm more ≥2 altered parameters: blood glucose, blood pressure, HDL cholesterol or triglycerides). Adjusted relative risk with the PA-GEE regression were obtained to determine the risk of acquiring the SM over the time (depending on the year of occupational medical examination). Results: Of the 1198 measurements workers, 93% (1109) were men, the median age was 33 years. 36% (428) had a parameter altered waist, and 100% of them had between 2 or more additional parameters altered for the diagnosis of metabolic syndrome. When performing multivariate statistics, adjusted for the time value of body mass index was found that for each year of age increased workers increased by 2% (95%CI: 1-4%) the risk of MS. Discussion: workers evaluated age was a risk factor for MS, this parameter and other relevant should be monitored by companies to generate policies for healthy lifestyle, to prevent chronic disease problems with potential implications workers, the company and society.
RESUMEN
Pluripotent stem cells possess complex systems that protect them from oxidative stress and ensure genomic stability, vital for their role in development. Even though it has been reported that antioxidant activity diminishes along stem cell differentiation, little is known about the transcriptional regulation of the involved genes. The reported modulation of some of these genes led us to hypothesize that some of them could be regulated by the transcription factors critical for self-renewal and pluripotency in embryonic stem cells (ESCs) and in induced pluripotent stem cells (iPSCs). In this work, we studied the expression profile of multiple genes involved in antioxidant defense systems in both ESCs and iPSCs. We found that Manganese superoxide dismutase gene (Mn-Sod/Sod2) was repressed during diverse differentiation protocols showing an expression pattern similar to Nanog gene. Moreover, Sod2 promoter activity was induced by Oct4 and Nanog when we performed a transactivation assay using two different reporter constructions. Finally, we studied Sod2 gene regulation by modulating the expression of Oct4 and Nanog in ESCs by shRNAs and found that downregulation of any of them reduced Sod2 expression. Our results indicate that pluripotency transcription factors positively modulate Sod2 gene transcription.
Asunto(s)
Proteínas de Homeodominio/metabolismo , Células Madre Pluripotentes Inducidas/fisiología , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Superóxido Dismutasa/genética , Animales , Diferenciación Celular , Línea Celular , Células Madre Embrionarias/citología , Regulación de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Proteínas de Homeodominio/genética , Células Madre Pluripotentes Inducidas/citología , Ratones , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/genética , Regiones Promotoras Genéticas , ARN Interferente Pequeño , Superóxido Dismutasa/metabolismoRESUMEN
INTRODUCTION: Mesenchymal stem cells (MSCs) are a promising source of cells for regenerative therapies. Although they can be isolated easily from several tissues, cell expansion is limited since their properties are lost with successive passages. Hence, pluripotent derived MSCs (PD-MSCs) arise as a suitable alternative for MSC production. Nevertheless, at present, PD-MSC derivation protocols are either expensive or not suitable for clinical purposes. METHODS: In this work we present a therapy-grade, inexpensive and simple protocol to derive MSCs from pluripotent stem cells (PSCs) based on the use of platelet lysate (PL) as medium supplement. RESULTS: We showed that the PD-MSCPL expressed multiple MSC markers, including CD90, CD73, CD105, CD166, and CD271, among others. These cells also show multilineage differentiation ability and immunomodulatory effects on pre-stimulated lymphocytes. Thorough characterization of these cells showed that a PD-MSCPL resembles an umbilical cord (UC) MSC and differs from a PSC in surface marker and extracellular matrix proteins and integrin expression. Moreover, the OCT-4 promoter is re-methylated with mesenchymal differentiation comparable with the methylation levels of UC-MSCs and fibroblasts. Lastly, the use of PL-supplemented medium generates significantly more MSCs than the use of fetal bovine serum. CONCLUSIONS: This protocol can be used to generate a large amount of PD-MSCs with low cost and is compatible with clinical therapies.
Asunto(s)
Plaquetas/metabolismo , Células Madre Mesenquimatosas/citología , Células Madre Pluripotentes/citología , Antígenos de Superficie/metabolismo , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Metilación de ADN , Células Madre Embrionarias Humanas/citología , Humanos , Péptidos y Proteínas de Señalización Intercelular/farmacología , Células Madre Mesenquimatosas/metabolismo , Microscopía Fluorescente , Fenotipo , Células Madre Pluripotentes/efectos de los fármacos , Células Madre Pluripotentes/metabolismo , Regiones Promotoras GenéticasRESUMEN
Embryonic stem cells (ESC) need a set of specific factors to be propagated. They can also grow in conditioned medium (CM) derived from a bovine granulosa cell line BGC (BGC-CM), a medium that not only preserves their main features but also increases ESC´s proliferation rate. The mitogenic properties of this medium were previously reported, ascribing this effect to an alternative spliced generated fibronectin isoform that contains the extra domain A (FN EDA(+)). Here, we investigated if the FN EDA(+) isoform increased proliferation of mouse and human ES cells. We analyzed cell proliferation using conditioned media produced by different mouse embryonic fibroblast (MEF) lines genetically engineered to express FN constitutively including or excluding the EDA domain (FN EDA(-)), and in media supplemented with recombinant peptides containing or not the EDA. We found that the presence of EDA in the medium increased mouse and human ESC's proliferation rate. Here we showed for the first time that this FN isoform enhances ESC's proliferation. These findings suggest a possible conserved behavior for regulation of ES cells proliferation by this FN isoform and could contribute to improve their culturing conditions both for research and cell therapy.
Asunto(s)
Células Madre Embrionarias/citología , Células Madre Embrionarias/efectos de los fármacos , Fibronectinas/metabolismo , Animales , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Medios de Cultivo Condicionados/farmacología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Fibronectinas/genética , Humanos , Ratones , Ratones MutantesRESUMEN
The degree to which children grow up in crowded housing is a neglected but potentially important aspect of social inequality. Poor living conditions can serve as a mechanism of social stratification, affecting children's wellbeing and resulting in the intergenerational transmission of social inequality. This paper reports an investigation of housing crowding on children's academic achievement, behavior, and health in the US and Los Angeles, a city with atypically high levels of crowding. We use data from the Panel Study of Income Dynamics' Child Development Supplement and the Los Angeles Family and Neighborhood Survey to explore the effect of living in a crowded home on an array of child wellbeing indicators. We find that several dimensions of children's wellbeing suffer when exposed to crowded living conditions, particularly in Los Angeles, even after controlling for socioeconomic status. The negative effects on children raised in crowded homes can persist throughout life, affecting their future socioeconomic status and adult wellbeing.
RESUMEN
Nine Acinetobacter strains from patients and hospital environment were analyzed for virulence markers, quorum sensing signal production, and the presence of luxI and luxR genes. The strains had several properties in common: growth in iron limited condition, biofilm formation, and no active protease secretion. Significantly higher catechol production was determined in patient isolates (P < 0.03), but other invasiveness markers, such as lipase secretion, amount of biofilm, cell motility, antibiotic resistance, and hemolysin production, showed large variability. Notably, all members of the so-called A. calcoaceticus-A. baumannii complex, regardless of whether the source was a patient or environmental, secreted mediumto long-chain N-acyl homoserine lactones (AHL) and showed blue light inhibition of cell motility. In these strains, a luxI homologue with a homoserine lactone synthase domain and a luxR putative regulator displaying the typical AHL binding domain were identified.
Asunto(s)
Infecciones por Acinetobacter/microbiología , Acinetobacter/patogenicidad , Infección Hospitalaria/microbiología , Acinetobacter/genética , Acinetobacter/metabolismo , Infecciones por Acinetobacter/metabolismo , Acil-Butirolactonas/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Secuencia de Bases , Biopelículas/crecimiento & desarrollo , Infección Hospitalaria/metabolismo , ADN Bacteriano/química , ADN Bacteriano/genética , Humanos , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Percepción de Quorum/fisiología , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Alineación de Secuencia , Análisis de Secuencia de ADN , Transactivadores/genética , Transactivadores/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , VirulenciaRESUMEN
Nine Acinetobacter strains from patients and hospital environment were analyzed for virulence markers, quorum sensing signal production, and the presence of luxI and luxR genes. The strains had several properties in common: growth in iron limited condition, biofilm formation, and no active protease secretion. Significantly higher catechol production was determined in patient isolates (P < 0.03), but other invasiveness markers, such as lipase secretion, amount of biofilm, cell motility, antibiotic resistance, and hemolysin production, showed large variability. Notably, all members of the so-called A. calcoaceticus-A. baumannii complex, regardless of whether the source was a patient or environmental, secreted mediumto long-chain N-acyl homoserine lactones (AHL) and showed blue light inhibition of cell motility. In these strains, a luxI homologue with a homoserine lactone synthase domain and a luxR putative regulator displaying the typical AHL binding domain were identified (AU)
No disponible
Asunto(s)
Acinetobacter/patogenicidad , Factores de Virulencia/análisis , Filogenia , Biopelículas/crecimiento & desarrollo , Farmacorresistencia BacterianaRESUMEN
Places are stratified along a hierarchy, with the affluent occupying the most resource-rich neighborhoods. Affluent neighborhood advantages include safety, high quality schools, and proximity to jobs. An additional benefit may be local economic stability over time. In a national context of rising interpersonal income inequality since 1970 and of the Great Recession, trends in neighborhood persistence and change expose this spatial advantage of the affluent. Using census data from 1970 to 2010, I find increasing rates of stability in the affluence and poverty of neighborhoods through 2000, with declines during the last decade. I also find that rates of chronic poverty and persistent affluence are high, ranging between 30 and 35 percent of neighborhoods across the 40-year period. This study highlights the structural persistence of affluence and poverty of neighborhoods as a vehicle for perpetuating social inequality and economic segregation.
RESUMEN
Induced pluripotent stem cells (iPSCs) are a promising type of stem cells, comparable to embryonic stem cells (ESCs) in terms of self-renew and pluripotency, generated by reprogramming somatic cells. These cells are an attractive approach to supply patient-specific pluripotent cells, for producing in vitro models of disease, drug discovery, toxicology and potentially treating degenerative disease circumventing immune rejection. In spite of the great advance since iPSCs' establishment, their obtention and propagation is an increasing area of great interest. In a recent work, we have shown that the conditioned medium from a bovine granulosa cell line (BGC-CM) is able to preserve the basic properties of mESCs. Therefore, based on our previous results and the reported resemblance between iPSCs and ESCs, we hypothesized that BGC-CM could provide a favorable context to culturing iPSCs. In this work, we have reprogrammed mouse embryonic fibroblasts obtaining iPSC lines, and showed that they can be propagated in BGC-CM while maintaining self-renewal and pluripotency, evidenced by expression of specific gene markers and capability of in vitro and in vivo differentiation to cell types from the three germ layers. We believe that these findings may provide a novel context to propagate iPSCs to study the molecular mechanisms involved in self-renewal and pluripotency.