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1.
Artigo em Inglês | MEDLINE | ID: mdl-38169039

RESUMO

Trisomy 12 is one of the most frequent chromosomal abnormalities in cultured human pluripotent stem cells (hPSCs). Although potential oncogenic properties and augmented cell cycle caused by trisomy 12 have been reported, the consequences of trisomy 12 in terms of cell differentiation, which is the basis for regenerative medicine, drug development, and developmental biology studies, have not yet been investigated. Here, we report that trisomy 12 compromises the mesendodermal differentiation of hPSCs. We identified sublines of hPSCs carrying trisomy 12 after their prolonged culture. Transcriptome analysis revealed that these hPSC sublines carried abnormal gene expression patterns in specific signaling pathways in addition to cancer-related cell cycle pathways. These hPSC sublines showed a lower propensity for mesendodermal differentiation in embryoid bodies cultured in a serum-free medium. BMP4-induced exit from the self-renewal state was impaired in the trisomy 12 hPSC sublines, with less upregulation of key transcription factor gene expression. As a consequence, the differentiation efficiency of hematopoietic and hepatic lineages was also impaired in the trisomy 12 hPSC sublines. We reveal that trisomy 12 disrupts the genome-wide expression patterns that are required for proper mesendodermal differentiation.

2.
Chemosphere ; 318: 137932, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36690258

RESUMO

From an environmental perspective, approaching sustainability requires a fundamental conceptual shift from the wastewater treatment process toward integrated treatment systems that consider efficient and effective utilization. This study aims to investigate the effects of different surfactants on the removal of perfluorooctanoic acid (PFOA). We used cationic surfactants as both frothers and collectors in the electrocoagulation-flotation (ECF) method to improve the removal efficiency of PFOA. The results showed that, under a monopolar aluminum electrode and with an initial PFOA concentration of 0.25 mM, the ECF method with decyl-trimethyl-ammonium bromide (DTAB) was able to remove over 98% of PFOA within 10 min. Cationic surfactants with a similar linear alkyl chain shape to PFOA, but a longer chain length, are more effective at removing PFOA through the ECF process. The removal mechanism is thought to involve co-precipitation with aluminum hydroxides through Al-F bonding, co-flotation with cationic surfactants, and mixed micelle formation with cationic surfactants. The optimal conditions were tested in both synthetic and realistic wastewater matrices and produced similar results. It has the potential for real wastewater application. The energy yield (G50) of ECF with 5 mM DTAB is 497 g·kWh-1, superior to other treatments, and is an extremely energy-effective method for separating PFOA from wastewater.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Alumínio , Conservação de Recursos Energéticos , Tensoativos , Eletrocoagulação/métodos
3.
Arch Pathol Lab Med ; 147(3): 348-358, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35738007

RESUMO

CONTEXT.­: Bone marrow (BM) samples are obtained through aspiration and trephine biopsy. Hemophagocytic lymphohistiocytosis (HLH) has been largely studied in BM aspirate smears. OBJECTIVE.­: To investigate the histologic features of HLH in trephine biopsy. DESIGN.­: Patients with hemophagocytosis in BM aspirate smears were assigned to HLH (n = 127) and non-HLH (n = 203) groups. We quantified hematoxylin-eosin and CD68 immunohistochemical staining of their trephine biopsies. RESULTS.­: No significant correlation was noted in the hemophagocytosis count between aspirate smears and trephine biopsies. Compared with the non-HLH group, the HLH group had a higher hemophagocytosis count (13 versus 9 per tissue section, P = .046), lower percentage of the adipocytic area (36.7% versus 50.3%, P < .001), and higher percentage of the foamy area (19.1% versus 14.5%, P < .001). The HLH group had more histiocyte infiltrates (total histiocyte density, 9.2% versus 7.3%; P < .001) and more fat-infiltrating histiocytes (histiocyte density of the fat-associated part [HD-FA], 7.6% versus 6.2%; P < .001). We identified the following poor prognostic factors in the HLH group: age 50 years or older (median overall survival [mOS], 95 versus 499 days; P = .04), Epstein-Barr virus-positive T-cell lymphoproliferative diseases (EBV+TLPDs) (mOS, 51 versus 425 days; P < .001), hemophagocytosis count of 6 or higher per tissue section (mOS, 66 versus 435 days; P = .02), and HD-FA of 9% or greater (mOS, 61 versus 359 days; P = .02). Multivariate analysis revealed that age 50 years or older (hazard ratio [HR], 2.38; P < .001), EBV+TLPDs (HR, 2.07; P < .001), and hemophagocytosis count of 6 or higher per tissue section (HR, 2.07; P = .002) were independent prognostic factors for HLH. CONCLUSIONS.­: The HLH group had higher hemophagocytic activity, higher cellularity, a more foamy appearance, more histiocyte infiltrates, and more fat-infiltrating histiocytes. High hemophagocytic activity and marked histiocyte infiltrates in the BM fat were associated with poorer prognosis.


Assuntos
Infecções por Vírus Epstein-Barr , Linfo-Histiocitose Hemofagocítica , Humanos , Pessoa de Meia-Idade , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/patologia , Infecções por Vírus Epstein-Barr/patologia , Medula Óssea/patologia , Herpesvirus Humano 4 , Biópsia
4.
J Hematop ; 16(2): 103-109, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38175441

RESUMO

Adult B-lineage acute lymphoblastic leukemia (B-ALL) with t(4;11)(q21;q23) is very rare. It is characterized by mixed-lineage leukemia and has the potential for lineage switching during the treatment course. We report the disease course of a patient with B-ALL with t(4;11)(q21;q23) to demonstrate that close monitoring of cell morphology and immunophenotyping is necessary to capture the lineage switch at an early stage. Cell morphology, immunophenotyping, and cytogenetics were used to evaluate the patient's disease status. A 36-year-old woman was diagnosed with B-ALL with t(4;11)(q21;q23), which encodes the KMT2A::AFF1 fusion. After the initial induction chemotherapy, her disease remained refractory, and the patient received salvage immunotherapy with blinatumomab and inotuzumab ozogamicin. However, the ALL did not respond. Repeated bone marrow examinations unexpectedly revealed the emergence of a major population of monoblasts, in addition to a minor population of the original B lymphoblasts. The patient was diagnosed with disease evolution from B-ALL to mixed-phenotype acute leukemia (MPAL, B/myeloid). We present this case to highlight the potential of KMT2A-rearranged B-ALL to undergo lineage switch following B-cell targeted therapy. Patients with this kind of B-ALL should therefore be closely monitored to capture potential changes in the nature of the disease and prompt appropriate treatment.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Adulto , Feminino , Linfócitos T , Imunoterapia , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Inotuzumab Ozogamicina
5.
J Microbiol Immunol Infect ; 55(2): 225-233, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33840606

RESUMO

OBJECTIVES: This study aimed to provide detailed genetic characterization of Tn6636, a multidrug-resistant and composite mobile element, in clinical isolates of Staphylococcus aureus. METHODS: A total of 112 ermB-positive methicillin-susceptible S. aureus (MSSA) and 224 ermB-positive methicillin-resistant S. aureus (MRSA) isolates collected from 2000 to 2015 were tested for the presence of Tn6636. Detection of the plasmids harboring Tn6636 was performed by S1 nuclease digestion pulsed-field gel electrophoresis (PFGE) analysis, conjugation test, and whole genome sequencing (WGS). RESULTS: Prevalence of Tn6636 in MSSA is higher than that in MRSA. Ten MSSA isolates and 10 MRSA isolates carried Tn6636. The 10 MSSA isolates belonged to three sequence types (ST), including ST7 (n = 6), ST5 (n = 3), and ST59 (n = 1). The 10 MRSA isolates belonged to ST188 (n = 8) and ST965 (n = 2). Analysis of plasmid sequences revealed that Tn6636 was harbored by six different mosaic plasmids. In addition to resistance genes, some plasmids also harbored toxin genes. CONCLUSION: The presence of multi-resistant Tn6636 in plasmids of both MSSA and MRSA with various STs suggests its broad dissemination. Results indicate that Tn6636 has existed for at least 16 years in Taiwan. The mosaic plasmids harboring Tn6636 can be transferred by conjugation. Ongoing surveillance of Tn6636 is essential to avoid continued spreading of resistant plasmids.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus
6.
Water Res ; 203: 117517, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34391021

RESUMO

The degradation of pharmaceuticals by electrochemical oxidation (EO) in simulated wastewater containing multiple pharmaceuticals was compared between batch and continuous reactors. Despite the excellent efficiencies achieved in batch experiments, the practical/large-scale applications of EO-degrading amine-containing pharmaceuticals has not yet been accomplished. This paper presents the results of continuous experiments with one of the most promising electrochemical configurations of Pt/Ti electrodes before proceeding to application. In the continuous electrooxidation system (without chloride), direct oxidation on the electrode surface and oxidation by hydroxyl radicals were the main pathways. Due to their short lifespans, the radicals could not be transferred to the bulk solution, and the removal of pharmaceuticals followed the order of sulfamethoxazole (SMX) > paracetamol (PAR) > diclofenac (DIC). In the electrochlorination system (with chloride), oxidation by residual chlorine was the main pathway. The removal of pharmaceuticals followed the order of sulfamethoxazole (SMX) > diclofenac (DIC) > paracetamol (PAR). High SMX removal was realized because of the high reaction rate of SMX with free chlorine. Among the pharmaceuticals, PAR had the lowest removal because it is a neutral species with a low mass transfer rate without the attraction of electrostatic force. These results are consistent with the predictions from our previous batch-scale study, which showed that the reaction rate of dissociated compounds could be increased by the addition of electrostatic force. Furthermore, multiple coexisting pharmaceuticals, such as SMX and PAR or DIC, may form dimers that can be transferred to complex structures and cause higher toxicity.


Assuntos
Preparações Farmacêuticas , Poluentes Químicos da Água , Aminas , Oxirredução , Sulfametoxazol , Águas Residuárias , Poluentes Químicos da Água/análise
7.
Int J Occup Saf Ergon ; 27(2): 351-357, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30822268

RESUMO

To design a comprehensive health and safety management performance system, extant literature on the health and safety performance indicators of and management systems for the application of occupational health and safety management systems was reviewed; additionally, the provisions of occupational health and safety laws were examined with a total of three main categories, including 28 active safety and health management performance categories. In the present study, health and safety management performance was evaluated by food manufacturing industry employees. An active performance evaluation questionnaire was developed by adopting the Delphi method to seek professional and expert opinion. With food manufacturing workers as participants, an in-depth discussion was conducted regarding the status of active health and safety performance indicators. Six active health and safety performance indicators were determined: emergency response; change management; procurement management; communication; prevention management; security behavior. These performance indicators have not been sufficiently implemented and require improvement.


Assuntos
Saúde Ocupacional , Indústria de Processamento de Alimentos , Humanos , Indústria Manufatureira , Gestão da Segurança , Inquéritos e Questionários
8.
Chemosphere ; 266: 128949, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33280843

RESUMO

Perfluorooctanoic acid (PFOA) was separated and recovered using a foam flotation process aided by cationic surfactants. The PFOA removal efficiency was in the following decreasing order: OTAB (C8TAB) > DTAB (C10TAB) > CTAB (C16TAB) > TBAB, which indicates that cationic surfactants with an alkyl chain that had a similar length to that of PFOA had higher affinities to PFOA. PFOA removal slightly decreased with increasing ionic strength of the surfactant but did not change with the pH. PFOA could be completely removed in 20 min with 1.25 mM of OTAB in actual wastewater. The energy yield value of foam flotation with a cationic surfactant was much higher than those of other methods, which means that using foam flotation with a cationic surfactant as the collector is a simple, fast, and energy-efficient method to separate and recover PFOA from dilute water solutions.


Assuntos
Fluorocarbonos , Tensoativos , Caprilatos , Águas Residuárias
9.
Artigo em Inglês | MEDLINE | ID: mdl-32585957

RESUMO

Amine-containing pharmaceuticals are the most often detected pharmaceuticals in wastewater and ambient aquatic environments. They can usually be degraded by manganese oxide (MnO2), which is a common natural oxidant in soils. Surfactants often coexist with pharmaceuticals in wastewater. Some amine-containing pharmaceuticals, such as diclofenac (DIC), are acidic and are thus ionic compounds in neutral conditions. These compounds, therefore, have similar properties to surfactants. Surfactants, thus, may influence the adsorption and degradation processes of DIC by MnO2. The effect of the type of surfactant on the degradation of DIC by MnO2 was investigated in this study with the addition of two common biodegradable surfactants (cetyltrimethyl-ammonium bromide (CTAB) and sodium dodecylsulfate (SDS)). The results indicated that the cationic surfactant (CTAB) significantly increased the degradation rate in neutral and alkaline conditions. On the other hand, the anionic surfactant (SDS) slightly increased the DIC removal rate in an acidic condition but significantly decreased the removal in neutral and alkaline conditions. Coexisting cationic surfactants not only influenced the kinetics but also altered the transformation mechanism of DIC by MnO2. Decarboxylation is the main transformation mechanism of DIC in the presence of CTAB, while both decarboxylation and hydroxylation are the main transformation mechanisms in the absence of CTAB.


Assuntos
Diclofenaco/farmacocinética , Compostos de Manganês/farmacologia , Tensoativos/farmacologia , Diclofenaco/química , Humanos , Óxidos , Tensoativos/química
10.
Water Res ; 155: 56-65, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30831424

RESUMO

Amine-containing pharmaceuticals such as acetaminophen, diclofenac, and sulfamethoxazole are the most often detected pharmaceuticals in wastewater and other aquatic environments. Amine-containing pharmaceuticals can be effectively removed by chlorination. These drugs, however, may coexist in wastewater. Thus, they may compete with each other, and their chlorinated products may react with each other to form new products. In this study, competitive effects of the above three amine-containing pharmaceuticals by chlorination and their products were investigated. The priority of chlorination of these compounds was dependent upon the pH of the solution, due to the dissociation of the compounds and hypochlorite. It followed the order of sulfamethoxazole > diclofenac > acetaminophen in an acidic condition, the order of sulfamethoxazole > acetaminophen > diclofenac in a neutral condition, and the order of sulfamethoxazole ≈ acetaminophen > diclofenac in an alkaline condition. Some of the chlorinated products in single- and multiple-compound systems were the same. Dimers of sulfamethoxazole and its chlorinated products, however, were not found, but dimers of sulfamethoxazole and acetaminophen or diclofenac were found in multiple-compound systems. This finding is important because it means that new products may be produced if different amine-containing pharmaceuticals react with free chlorine simultaneously.


Assuntos
Halogenação , Poluentes Químicos da Água , Diclofenaco , Sulfametoxazol , Águas Residuárias
11.
J Hazard Mater ; 366: 592-605, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30576998

RESUMO

This study investigated the direct and indirect electro-oxidation of amine-containing pharmaceuticals (acetaminophen (ACT), diclofenac (DIC), and sulfamethoxazole (SMX)) by using graphite electrodes, and to compare the influence by using different electrolytes (Na2SO4 and NaCl). Under the optimum conditions of current (I) at 0.5 A, in direct system, 74.3%, 90.0%, 81.6% of ACT, DIC, and SMX were respectively removed after 60 min (k = 0.023, 0.037, 0.027 min-1), 48.9%, 85.9%, 68.2% of TOC respectively removed after reaction time. In contrast, at the same current intensity, in indirect system, ACT, DIC, and SMX were eliminated within 30 min (k = 0.117, 0.307, 0.170 min-1), 89.6%, 92.6%, 99.6% of TOC respectively removed after reaction time. The results indicated that the dissociated compounds were attracted to the anode due to electrostatic forces and had higher mass transformation rates in the direct electro-oxidation process. According to the cyclic voltammogram, indirect oxidation occurred when active chlorine species were generated from chloride ions anodically to destroy pollutants. Based on intermediates detected during electro-oxidation treatment by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), only oxidized intermediates were found in the direct oxidation system, while both oxidized and chlorinated intermediates were found in the indirect oxidation system.


Assuntos
Aminas/análise , Eletrodos , Grafite/química , Preparações Farmacêuticas/química , Oxirredução
12.
Int J Dev Biol ; 62(9-10): 613-621, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30378385

RESUMO

Cell morphology is recognized as an important hallmark of neural cells. During the differentiation of human pluripotent stem cells (hPSCs) into neural cells, cell morphology changes dynamically. Therefore, characterization of the morphology of cells during this period is important to improve our understanding of the differentiation and development of neural cells. General methods for the directed induction of hPSCs include the steps of multi-cellular aggregation or high-density cell culture, particularly at the early phase of neural differentiation, and therefore, the morphology of each differentiating cell is difficult to recognize. Here, we have developed a new method for the directed differentiation of neuroepithelial-like cells (NELCs) from hPSCs at a low cell density in an adherent monolayer culture, as well as an image-processing algorithm to evaluate the cell morphology of differentiating NELCs, in order to follow cell morphology during the differentiation of hPSCs into NELCs. Using these methods, the morphological transition of differentiating cells was observed in real time using phase contrast imaging and then quantified. Because cell morphology is also considered an inherent biological marker of neural cells cultured in vitro, this method is potentially useful to study the mechanisms underlying neural cell differentiation.


Assuntos
Diferenciação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Células Neuroepiteliais/citologia , Neurogênese , Neurônios/citologia , Biomarcadores/metabolismo , Técnicas de Cultura de Células , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células Neuroepiteliais/metabolismo , Neurônios/metabolismo
13.
Exp Cell Res ; 352(2): 333-345, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28215634

RESUMO

Limited growth potential, narrow ranges of sources, and difference in variability and functions from batch to batch of primary hepatocytes cause a problem for predicting drug-induced hepatotoxicity during drug development. Human pluripotent stem cell (hPSC)-derived hepatocyte-like cells in vitro are expected as a tool for predicting drug-induced hepatotoxicity. Several studies have already reported efficient methods for differentiating hPSCs into hepatocyte-like cells, however its differentiation process is time-consuming, labor-intensive, cost-intensive, and unstable. In order to solve this problem, expansion culture for hPSC-derived hepatic progenitor cells, including hepatic stem cells and hepatoblasts which can self-renewal and differentiate into hepatocytes should be valuable as a source of hepatocytes. However, the mechanisms of the expansion of hPSC-derived hepatic progenitor cells are not yet fully understood. In this study, to isolate hPSC-derived hepatic progenitor cells, we tried to develop serum-free growth factor defined culture conditions using defined components. Our culture conditions were able to isolate and grow hPSC-derived hepatic progenitor cells which could differentiate into hepatocyte-like cells through hepatoblast-like cells. We have confirmed that the hepatocyte-like cells prepared by our methods were able to increase gene expression of cytochrome P450 enzymes upon encountering rifampicin, phenobarbital, or omeprazole. The isolation and expansion of hPSC-derived hepatic progenitor cells in defined culture conditions should have advantages in terms of detecting accurate effects of exogenous factors on hepatic lineage differentiation, understanding mechanisms underlying self-renewal ability of hepatic progenitor cells, and stably supplying functional hepatic cells.


Assuntos
Técnicas de Reprogramação Celular/métodos , Células-Tronco Embrionárias/citologia , Hepatócitos/citologia , Células-Tronco Pluripotentes/citologia , Diferenciação Celular , Células Cultivadas , Meios de Cultura Livres de Soro/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo
14.
Stem Cells Dev ; 25(24): 1884-1897, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27733097

RESUMO

Functional hepatocytes derived from human pluripotent stem cells (hPSCs) have potential as tools for predicting drug-induced hepatotoxicity in the early phases of drug development. However, the propensity of hPSC lines to differentiate into specific lineages is reported to differ. The ability to predict low propensity of hPSCs to differentiate into hepatocytes would facilitate the selection of useful hPSC clones and substantially accelerate development of hPSC-derived hepatocytes for pharmaceutical research. In this study, we compared the expression of genes associated with hepatic differentiation in five hPSC lines including human ES cell line, H9, which is known to differentiate into hepatocytes, and an hPSC line reported with a poor propensity for hepatic differentiation. Genes distinguishing between undifferentiated hPSCs, hPSC-derived hepatoblast-like differentiated cells, and primary human hepatocytes were drawn by two-way cluster analysis. The order of expression levels of genes in undifferentiated hPSCs was compared with that in hPSC-derived hepatoblast-like cells. Three genes were selected as predictors of low propensity for hepatic differentiation. Expression of these genes was investigated in 23 hPSC clones. Review of representative cells by induction of hepatic differentiation suggested that low prediction scores were linked with low hepatic differentiation. Thus, our model using gene expression ranking and bioinformatic analysis could reasonably predict poor differentiation propensity of hPSC lines.


Assuntos
Diferenciação Celular/genética , Regulação da Expressão Gênica , Hepatócitos/citologia , Células-Tronco Pluripotentes/citologia , Linhagem Celular , Linhagem da Célula/genética , Análise por Conglomerados , Endoderma/citologia , Perfilação da Expressão Gênica , Estudos de Associação Genética , Hepatócitos/metabolismo , Humanos , Células-Tronco Pluripotentes/metabolismo
15.
Sci Rep ; 6: 34009, 2016 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-27667091

RESUMO

Given the difficulties inherent in maintaining human pluripotent stem cells (hPSCs) in a healthy state, hPSCs should be routinely characterized using several established standard criteria during expansion for research or therapeutic purposes. hPSC colony morphology is typically considered an important criterion, but it is not evaluated quantitatively. Thus, we designed an unbiased method to evaluate hPSC colony morphology. This method involves a combination of automated non-labelled live-cell imaging and the implementation of morphological colony analysis algorithms with multiple parameters. To validate the utility of the quantitative evaluation method, a parent cell line exhibiting typical embryonic stem cell (ESC)-like morphology and an aberrant hPSC subclone demonstrating unusual colony morphology were used as models. According to statistical colony classification based on morphological parameters, colonies containing readily discernible areas of differentiation constituted a major classification cluster and were distinguishable from typical ESC-like colonies; similar results were obtained via classification based on global gene expression profiles. Thus, the morphological features of hPSC colonies are closely associated with cellular characteristics. Our quantitative evaluation method provides a biological definition of 'hPSC colony morphology', permits the non-invasive monitoring of hPSC conditions and is particularly useful for detecting variations in hPSC heterogeneity.

16.
In Vitro Cell Dev Biol Anim ; 51(8): 769-75, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25898826

RESUMO

Neural differentiation is an important target of human embryonic stem cells, which provide a source for cell-based therapy, developmental biology, and pharmaceutical research. Previous studies revealed that inhibition of the bone morphogenetic protein is required for neural induction from human embryonic stem cells. On the contrary, the functions of fibroblast growth factors and Activin/Nodal signaling are controversial. Fibroblast growth factor-2 and Activin/Nodal pathways exert divergent influences on human embryonic stem cell concerning the maintenance of both pluripotency and cellular differentiation. We hypothesized that the combination of fibroblast growth factor-2 and Activin A at various concentrations synergistically exerts diverse effects on cell differentiation. To determine the effects of fibroblast growth factor-2 and Activin A on cellular differentiation into neural lineages, we examined the expression of neural differentiation markers in human embryonic stem cells treated with fibroblast growth factor-2 and/or Activin A at various concentrations in a growth factor-defined serum-free medium in short-term culture. In this study, we provide evidence that fibroblast growth factor-2 and Activin A synergistically regulated the initiation of human embryonic stem cell differentiation into neural cell lineages even though human embryonic stem cells autonomously differentiate into neural cell lineages.


Assuntos
Ativinas/farmacologia , Diferenciação Celular/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/fisiologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Células-Tronco Pluripotentes/fisiologia
17.
Nature ; 486(7403): 415-9, 2012 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-22722204

RESUMO

The modification of DNA by 5-methylcytosine (5mC) has essential roles in cell differentiation and development through epigenetic gene regulation. 5mC can be converted to another modified base, 5-hydroxymethylcytosine (5hmC), by the tet methylcytosine dioxygenase (Tet) family of enzymes. Notably, the balance between 5hmC and 5mC in the genome is linked with cell-differentiation processes such as pluripotency and lineage commitment. We have previously reported that the maternal factor PGC7 (also known as Dppa3, Stella) is required for the maintenance of DNA methylation in early embryogenesis, and protects 5mC from conversion to 5hmC in the maternal genome. Here we show that PGC7 protects 5mC from Tet3-mediated conversion to 5hmC by binding to maternal chromatin containing dimethylated histone H3 lysine 9 (H3K9me2) in mice. In addition, imprinted loci that are marked with H3K9me2 in mature sperm are protected by PGC7 binding in early embryogenesis. This type of regulatory mechanism could be involved in DNA modifications in somatic cells as well as in early embryos.


Assuntos
5-Metilcitosina/metabolismo , Citosina/análogos & derivados , Embrião de Mamíferos/metabolismo , Histonas/química , Histonas/metabolismo , Proteínas Repressoras/metabolismo , Animais , Cromatina/química , Cromatina/metabolismo , Proteínas Cromossômicas não Histona , Citosina/metabolismo , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Dioxigenases , Embrião de Mamíferos/embriologia , Desenvolvimento Embrionário , Feminino , Impressão Genômica/genética , Lisina/química , Lisina/metabolismo , Masculino , Metilação , Camundongos , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , RNA Longo não Codificante , RNA não Traduzido/genética , Espermatozoides/metabolismo , ras-GRF1/genética
18.
Biol Reprod ; 86(2): 40, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22034526

RESUMO

Dynamic alterations in chromatin configuration occur in mammalian oocytogenesis. Based on chromatin configuration patterns, fully grown oocytes are classified into two types. One is surrounded nucleolus (SN)-type and the other is nonsurrounded nucleolus (NSN)-type oocytes. Although chromatin condensation during the transition from NSN- to SN-type oocytes is a prerequisite for normal early embryonic development, the molecular mechanisms remain unclear. In this study, we analyzed the role of DPPA3 (also known as PGC7/Stella) in this transition using Dppa3-null oocytes. The NSN-to-SN transition was significantly impaired, and transcriptional repression was incomplete in the Dppa3-null oocytes. Additionally, we revealed that prior transcriptional repression was necessary for the NSN-to-SN transition. These findings demonstrate that DPPA3 is an essential factor for the production of functional oocytes through transcriptional repression and chromatin condensation.


Assuntos
Cromatina/fisiologia , Oócitos/fisiologia , Oogênese/fisiologia , Proteínas Repressoras/fisiologia , Animais , Nucléolo Celular/fisiologia , Proteínas Cromossômicas não Histona , Feminino , Heterocromatina/fisiologia , Histonas/fisiologia , Camundongos , Camundongos Knockout , Oócitos/citologia , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Transcrição Gênica/fisiologia
19.
Hepatol Res ; 39(6): 625-31, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19260995

RESUMO

Severe intrahepatic cholestasis with low serum gamma-glutamyltranspeptidase (gamma-GT) activity is exceptionally rare in adult patients, and its association with multi-genetic alterations of bile salt transporters has not been reported. We investigated a 25-year-old man presenting with a four-year history of jaundice. Laboratory and radiographic examinations revealed clinical pictures of progressive intrahepatic cholestasis with low gamma-GT. Serial liver histopathology demonstrated cirrhosis resulting from progressive persistent cholestatic injury. Genetic sequencing studies for the entire coding exons of ATP8B1 and ABCB11 uncovered a heterozygous missense mutation 1798 C->T (R600W) in ATP8B1, and a homozygous nucleotide substitution 1331 T->C (V444A) in ABCB11. In conclusion, this is a rare case of adult onset progressive intrahepatic cholestasis with low gamma-GT associated with heterozygous ATP8B1 mutation and homozygous ABCB11 polymorphism. Further studies are necessary to investigate the impact of heterozygous R600W mutation and whether other cholestatic disorders are multi-genetic.

20.
J Gastroenterol Hepatol ; 23(9): 1390-3, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18853996

RESUMO

BACKGROUND AND AIM: Progressive familial intrahepatic cholestasis type 2 (PFIC2) results from genetic defects of the hepatobiliary bile salt export pump (BSEP, ABCB11) at chromosome 2q24. Patients with progressive cholestasis and liver cirrhosis usually need liver transplantation in the first decade. Mutations in ABCB11 are also associated with benign recurrent intrahepatic cholestasis type 2 and intrahepatic cholestasis of pregnancy in adult patients. We aimed to make the prenatal diagnosis of PFIC2. METHODS: Genetic diagnosis was performed by genomic DNA analysis. Prenatal genetic diagnosis was made by fetal amniotic DNA and chorionic DNA analysis. RESULTS: We report on two families of PFIC2 with inherited compound heterozygous mutations of ABCB11 (M183V and R303K in Family 1, V284L and 1145delC in Family 2) from the parents. An infant with heterozygous M183V mutation was later born healthy in Family 1. A fetus with compound heterozygous missense mutation V284L and 1145delC was terminated in Family 2. CONCLUSION: Prenatal diagnosis of PFIC2 was helpful to prevent further affected children in families with this fatal disease.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Colestase Intra-Hepática/diagnóstico , Testes Genéticos , Mutação , Diagnóstico Pré-Natal/métodos , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP , Aborto Induzido , Amniocentese , Colestase Intra-Hepática/genética , Amostra da Vilosidade Coriônica , Análise Mutacional de DNA , Progressão da Doença , Evolução Fatal , Feminino , Heterozigoto , Humanos , Recém-Nascido , Nascido Vivo , Masculino , Linhagem , Gravidez
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