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1.
Planta Med ; 90(2): 111-125, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37935353

RESUMO

Seborrheic dermatitis is a chronic inflammatory disease caused by Malassezia yeast species that affects the regions of the body where the sebaceous glands are present. The combined use of different essential oils (EOs) can increase their spectrum of action. Thus, the present study aimed to evaluate the action of EOs alone and in combination with each other on M. furfur, in planktonic and biofilm form, and their anti-inflammatory and mutagenic potential, in addition to the effects on the viability of cells lines. Of the 40 evaluated EOs, 22 showed activity against M. furfur at 0.5 - 2.0 mg/mL concentrations. Among the most active species, a blend of essential oils (BEOs) composed of Cymbopogon martini (Roxb.) Will. Watson (MIC = 0.5 mg/mL) and Mentha × piperita L. (MIC = 1.0 mg/mL) was selected, which showed a synergistic effect against yeast when evaluated through the checkerboard assay. The fungicidal activity was maintained by the addition of anti-inflammatory oil from Varronia curassavica Jacq. to BEOs. The BEOs also showed activity in the inhibition of biofilm formation and in the eradication of the biofilm formed by M. furfur, being superior to the action of fluconazole. Furthermore, it did not show mutagenic potential and did not interfere with the cell viability of both evaluated cell lines (HaCaT and BMDMs). TNF-α levels were reduced only by C. martini; however, this property was maintained when evaluating BEOs. BEOs had no effect on IL-8 levels. Thus, the BEOs may be indicated for alternative treatments against seborrheic dermatitis.


Assuntos
Dermatite Seborreica , Malassezia , Óleos Voláteis , Antifúngicos/farmacologia , Óleos Voláteis/farmacologia , Dermatite Seborreica/tratamento farmacológico , Anti-Inflamatórios/farmacologia
2.
Polymers (Basel) ; 15(4)2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36850198

RESUMO

Sterilization is a fundamental step to eliminate microorganisms prior to the application of products, especially in the food and medical industries. γ-irradiation is one of the most recommended and effective methods used for sterilization, but its effect on the properties and performance of bio-based polymers is negligible. This work is aimed at evaluating the influence of γ-radiation at doses of 5, 10, 15, 25, 30, and 40 kGy on the morphology, properties, and performance of bioplastic produced from onion bulb (Allium cepa L.), using two hydrothermal synthesis procedures. These procedures differ in whether the product is washed or not after bioplastic synthesis, and are referred to as the unwashed hydrothermally treated pulp (HTP) and washed hydrothermally treated pulp (W-HTP). The morphological analysis indicated that the film surfaces became progressively rougher and more irregular for doses above 25 kGy, which increases their hydrophobicity, especially for the W-HTP samples. In addition, the FTIR and XRD results indicated that irradiation changed the structural and chemical groups of the samples. There was an increase in the crystallinity index and a predominance of the interaction of radiation with the hydroxyl groups-more susceptible to the oxidative effect-besides the cleavage of chemical bonds depending on the γ-radiation dose. The presence of soluble carbohydrates influenced the mechanical behavior of the samples, in which HTP is more ductile than W-HTP, but γ-radiation did not cause a change in mechanical properties proportionally to the dose. For W-HTP, films there was no mutagenicity or cytotoxicity-even after γ-irradiation at higher doses. In conclusion, the properties of onion-based films varied significantly with the γ-radiation dose. The films were also affected differently by radiation, depending on their chemical composition and the change induced by washing, which influences their use in food packaging or biomedical devices.

3.
Planta Med ; 89(2): 158-167, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36170858

RESUMO

Guttiferone E (GE) is a benzophenone found in Brazilian red propolis. In the present study, the effect of GE on human (A-375) and murine (B16-F10) melanoma cells was investigated. GE significantly reduced the cellular viability of melanoma cells in a time-dependent manner. In addition, GE demonstrated antiproliferative effect, with IC50 values equivalent to 9.0 and 6.6 µM for A-375 and B16-F10 cells, respectively. The treatment of A-375 cells with GE significantly increased cell populations in G0/G1 phase and decreased those in G2/M phase. Conversely, on B16-F10 cells, GE led to a significant decrease in the populations of cells in G0/G1 phase and concomitantly an increase in the population of cells in phase S. A significantly higher percentage of apoptotic cells was observed in A-375 (43.5%) and B16-F10 (49.9%) cultures after treatment with GE. Treatments with GE caused morphological changes and significant decrease to the melanoma cells' density. GE (10 µM) inhibited the migration of melanoma cells, with a higher rate of inhibition in B16-F10 cells (73.4%) observed. In addition, GE significantly reduced the adhesion of A375 cells, but showed no effect on B16-F10. Treatment with GE did not induce changes in P53 levels in A375 cultures. Molecular docking calculations showed that GE is stable in the active sites of the tubulin dimer with a similar energy to taxol chemotherapy. Taken together, the data suggest that GE has promising antineoplastic potential against melanoma.


Assuntos
Antineoplásicos , Melanoma Experimental , Melanoma , Humanos , Animais , Camundongos , Linhagem Celular Tumoral , Proliferação de Células , Simulação de Acoplamento Molecular , Antineoplásicos/uso terapêutico , Benzofenonas/farmacologia , Benzofenonas/uso terapêutico , Melanoma/tratamento farmacológico , Melanoma Experimental/tratamento farmacológico , Camundongos Endogâmicos C57BL
4.
Toxicol Res (Camb) ; 11(5): 750-757, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36337250

RESUMO

INTRODUCTION: Red propolis is synthetized from exudates of Dalbergia ecastophyllum (L) Taub. and Symphonia globulifera L.f., presents isoflavones, guttiferone E, xanthochymol, and oblongifolin B and has anti-inflammatory, antioxidant, and antiproliferative activities. OBJECTIVES: This study aimed to evaluate the antigenotoxic and anticarcinogenic potential of red propolis hydroalcoholic extract (RPHE) in rodents. METHODS: The influence of RPHE in doxorubicin (DXR)-induced genotoxicity was investigated through the micronucleus test in Swiss mice. Blood samples were also collected to investigate oxidative stress, hepatotoxicity, and nephrotoxicity. Was investigated the influence of RPHE in 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci, as well as its influence in proliferating cell nuclear antigen (PCNA) and the cyclooxygenase-2 (COX-2) expression in colon of rats, by immunohistochemistry. RESULTS: The results showed that RPHE (48 mg/kg) reduced DXR-induced genotoxicity. Animals treated with DXR showed significantly lower GSH serum levels in comparison to the negative control. RPHE treatments did not attenuated significantly the DXR-induced GSH depletion. No difference was observed in cytotoxicity parameters of mice hematopoietic tissues between the treatment groups, as well as the biochemical parameters of hepatotoxicity and nephrotoxicity. RPHE (12 mg/kg) reduced the DMH-induced carcinogenicity and toxicity, as well as DMH-induced PCNA and COX-2 expression in colon tissue. CONCLUSION: Therefore, was observed that the RPHE has chemopreventive effect, associated to antiproliferative and anti-inflammatory activities.

5.
J Pharm Pharmacol ; 74(5): 740-749, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35299250

RESUMO

OBJECTIVES: Dalbergia ecastaphyllum (L.) Taub. is a semi-prostrate species associated with estuaries, mangroves and dunes. This plant species has great ecological and economic importance, especially concerning apiculture pasture and Brazilian red propolis production. In this study, non-clinical toxicological evaluations of the hydroalcoholic extract of D. ecastaphyllum stems (DEHE), the resin production source, were conducted. In addition, the action of DEHE on genomic instability and colon carcinogenesis was investigated. METHODS AND RESULTS: The extract's chemical profile was analysed by HPLC, and medicarpin, vestitol and neovestitol were found as major compounds. DEHE showed an IC50 equivalent to 373.2 µg/ml and LC50 equal 24.4 mg/L, when evaluated using the XTT colorimetric test and the zebrafish acute toxicity assay, respectively. DEHE was neither genotoxic nor cytotoxic at the highest dose, 2000 mg/kg, by peripheral blood micronucleus test. The treatments DEHE (6 and 24 mg/kg) led to the reduction of micronuclei induced by doxorubicin (DXR) in mice. Furthermore, significantly higher serum levels of reduced glutathione were observed in animals treated with DEHE plus DXR, revealing an antioxidant effect. Treatments with DEHE (48 mg/kg) led to a significant reduction in pre-neoplastic lesions induced by the 1,2-dimethylhydrazine (DMH) carcinogen in the rat colon. Immunohistochemical analysis revealed significantly lower levels of expression of COX-2 (86%) and PCNA (83%) in the colon of rats treated with DEHE plus DMH, concerning those treated with the carcinogen. CONCLUSIONS: These results indicate the involvement of anti-inflammatory and antiproliferative pathways in the protective effect of DEHE.


Assuntos
Dalbergia , Própole , Animais , Camundongos , Ratos , Brasil , Carcinógenos , Quimioprevenção , Dalbergia/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Própole/química , Própole/farmacologia , Peixe-Zebra
6.
Eur J Pharm Sci ; 160: 105739, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33524503

RESUMO

The synthetic polyhexamethylene guanidine hydrochloride (PHMGH) polymer presents antifungal and antimicrobial activities in vitro. However, in vivo reports regarding its antiseptic and healing activity are scarce in the scientific literature. Thus, the present study aimed to evaluate the antimicrobial and healing effects, as well as toxicological parameters, of a topical solution containing 0.5% PHMGH (Akwaton®) in the treatment of superficial skin wounds experimentally induced on the dorsum of rodents. In addition, non-clinical safety studies were also conducted for use in human health, such as acute oral toxicity and genotoxicity tests. Animals did clinically not present dermatitis. After two days of topical treatment, PHMGH showed a significant antiseptic effect compared to the untreated group, reducing the number of colony-forming units by 72%, reaching 100% on the fourth day of treatment. The animals treated with PHMGH showed a significant area reduction of the skin lesions in relation to the untreated group, indicating a healing effect of the polymer. Moreover, PHMGH treatment led to a significant increase in fibroblasts when compared to the untreated group, revealing its healing action. No significant differences were observed between the biochemical indicators of hepatoxicity and nephrotoxicity, nor genotoxicity between the PHMGH-treated and the negative control groups. The results of acute oral toxicity showed that PHMGH at 5% presents a lethal dose 50% greater than the 2000 mg/kg. At a concentration of 5%, PHMGH did not show genotoxicity nor cytotoxicity at doses up to 1500 mg/kg through the micronucleus assay in mice. Therefore, 0.5% PHMGH showed an antimicrobial and healing effect, with no toxicity, and could be a promising adjunct in the microbial control of healing wounds.


Assuntos
Anti-Infecciosos Locais , Anti-Infecciosos , Animais , Antibacterianos , Anti-Infecciosos Locais/toxicidade , Guanidina/toxicidade , Camundongos , Cicatrização
7.
Cad. saúde colet., (Rio J.) ; 28(3): 422-425, jul.-set. 2020. tab
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1132972

RESUMO

Resumo Introdução A goiaba é um fruto amplamente utilizado como alimento e é considerada planta medicinal em países tropicais e subtropicais. Pesquisas têm mostrado que o fruto contém constituintes químicos com abrangente uso clínico. Além disso, a maior parte das substâncias utilizadas no tratamento contra câncer foi isolada a partir de produtos naturais. Objetivo Avaliar o potencial citotóxico, mutagênico, antimutagênico e quimioprotetor da fruta liofilizada de Psidium guajava, a goiaba, in vivo. Método A citotoxicidade, a mutagenicidade e a antimutagenicidade foram avaliadas em três diferentes dosagens (0,625, 1,25 e 2,50 g/kg) de goiaba. Resultados Os resultados mostraram que a goiaba não apresentou atividade citotóxica e mutagênica no ensaio de micronúcleo em sangue periférico e que não houve alterações nos valores de ALT e AST, indicando ausência de toxicidade hepática. Nos animais tratados com a goiaba, a dose de 0,625 mg/kg significativamente reduziu os danos induzidos pela doxorrubicina. Conclusão Esses resultados mostraram que o consumo de goiaba é seguro e capaz de proteger o material genético de alterações genômicas.


Abstract Background Guava is a fruit widely used as food and is considered a medicinal plant in the tropical and subtropical countries. Scientific research has shown that the fruit contains chemical constituents with comprehensive clinical use. In addition, most of the substances used in cancer treatment have been isolated from natural products. Objective To evaluate the cytotoxic, mutagenic, antimutagenic, and chemoprotective potential of the freeze-dried fruit of Psidium guajava, guava, in vivo. Method Cytotoxicity, mutagenicity, and antimutagenicity were evaluated in three different dosages (0.625, 1.25, 2.50 g/kg) of guava. Results The results show that guava does not present cytotoxic 2 and mutagenic activity in the micronucleus assay in peripheral blood and there were no alterations in ALT and AST values showing the absence of hepatic toxicity. In animals treated with guava, the dose of 0.625 mg/kg significantly reduced the damage induced by doxorubicin. Conclusion These results show that guava consumption is safe as it is also capable of protecting the genetic material from changes.

8.
Food Chem Toxicol ; 138: 111228, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32112866

RESUMO

Betulinic acid (BA) is a pentacyclic triterpenoid found in several plant species. Urethane (URE) is a known promutagen. Here, we examine the genotoxicity and mutagenicity of BA alone or in combination with URE using the bone marrow micronucleus assay in mice bone marrow cells and the Somatic Mutation and Recombination Test in Drosophila melanogaster. Findings revealed that BA alone was not genotoxic, but reduced the frequency of micronucleus when compared to the positive control. No significant differences were observed in the cytotoxicity. Biochemical analyzes showed no significant differences for liver (AST and ALT) or renal (creatinine and urea) function parameters, indicating the absence of hepatotoxic and nephrotoxic effects. BA alone did not increase the frequency of mutant spots, but reduced the total frequency of mutant spots when co-administered with URE in both ST and HB crosses. In addition, BA reduced the recombinogenic effect of URE at the highest concentrations of both crosses. In conclusion, under experimental conditions, BA has modulatory effects on the genotoxicity induced by URE in mice, as well as in somatic cells of D. melanogaster. We suggest that the modulatory effects of BA may be mainly due to its antioxidant and apoptotic properties.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Mutagênese/efeitos dos fármacos , Triterpenos/farmacologia , Uretana/toxicidade , Animais , Antimutagênicos/farmacologia , Antioxidantes/farmacologia , Medula Óssea/efeitos dos fármacos , Carcinógenos/farmacologia , Drosophila melanogaster/genética , Feminino , Cabelo/efeitos dos fármacos , Masculino , Camundongos , Testes de Mutagenicidade , Triterpenos Pentacíclicos , Taxa de Sobrevida , Tricomas/efeitos dos fármacos , Triterpenos/química , Asas de Animais/efeitos dos fármacos , Ácido Betulínico
9.
J Toxicol Environ Health A ; 82(6): 401-410, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31066341

RESUMO

Usnic acid (UA) is one of the pharmacologically most important compounds produced by several lichen species. To better understand the mechanism of action (MOA) of this important substance, this study examined the genotoxicity attributed to UA and its influence on mutagens with varying MOA using the micronucleus (MN) test in Chinese hamster ovary cells (CHO). Additional experiments were conducted to investigate the effect of UA on colon carcinogenesis in Wistar rats employing the aberrant crypt focus (ACF) assay. In vitro studies showed a significant increase in the frequency of MN in cultures treated with the highest UA concentration tested (87.13 µM). In contrast, UA concentrations of 10.89, 21.78, or 43.56 µM produced an approximate 60% reduction in chromosomal damage induced by doxorubicin, hydrogen peroxide, and etoposide, indicating an antigenotoxic effect. In the ACF assay, male Wistar rats treated with different UA doses (3.125, 12.5, or 50 mg/kg b.w.) and with the carcinogen 1,2-dimethylhydrazine exhibited a significantly lower incidence of neoplastic lesions in the colon than animals treated only with the carcinogen. Data suggest that the MOA responsible for the chemopreventive effect of UA may be related to interaction with DNA topoisomerase II and/or the antioxidant potential of the compound.


Assuntos
Anticarcinógenos/farmacologia , Benzofuranos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Instabilidade Genômica/efeitos dos fármacos , Lesões Pré-Cancerosas/tratamento farmacológico , Animais , Células CHO , Cricetinae , Cricetulus , Testes de Mutagenicidade
10.
Development ; 146(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30709911

RESUMO

Most cells in our body communicate during development and throughout life via Notch receptors and their ligands. Notch receptors relay information from the cell surface to the genome via a very simple mechanism, yet Notch plays multiple roles in development and disease. Recent studies suggest that this versatility in Notch function may not necessarily arise from complex and context-dependent integration of Notch signaling with other developmental signals, but instead arises, in part, from signaling dynamics. Here, we review recent findings on the core Notch signaling mechanism and discuss how spatial-temporal dynamics contribute to Notch signaling output.


Assuntos
Receptores Notch/metabolismo , Transdução de Sinais , Animais , Humanos , Receptores Notch/genética
11.
Methods Mol Biol ; 1516: 101-119, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27106496

RESUMO

Mouse Embryonic Stem cells (mESCs) show heterogeneous and dynamic expression of important pluripotency regulatory factors. Single-cell analysis has revealed the existence of cell-to-cell variability in the expression of individual genes in mESCs. Understanding how these heterogeneities are regulated and what their functional consequences are is crucial to obtain a more comprehensive view of the pluripotent state.In this chapter we describe how to analyze transcriptional heterogeneity by monitoring gene expression of Nanog, Oct4, and Sox2, using single-molecule RNA FISH in single mESCs grown in different cell culture medium. We describe in detail all the steps involved in the protocol, from RNA detection to image acquisition and processing, as well as exploratory data analysis.


Assuntos
Técnicas de Cultura de Células/métodos , Hibridização in Situ Fluorescente/métodos , Células-Tronco Embrionárias Murinas/citologia , Análise de Célula Única/métodos , Transcrição Gênica , Animais , Diferenciação Celular/genética , Perfilação da Expressão Gênica , Heterogeneidade Genética , Camundongos , Proteína Homeobox Nanog/genética , Fator 3 de Transcrição de Octâmero/genética , Células-Tronco Pluripotentes/citologia , Fatores de Transcrição SOXB1/genética
12.
Methods Mol Biol ; 1341: 87-100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26162772

RESUMO

The current view of the pluripotent state is that of a transient, dynamic state, maintained by the balance between opposing cues. Understanding how this dynamic state is established in pluripotent cells and how it relates to gene expression is essential to obtain a more detailed description of the pluripotent state.In this chapter, we describe how to study the dynamic expression of a core pluripotency gene regulator-Nanog-by exploiting single-cell time-lapse imaging of a reporter mESC line grown in different cell culture media. We further describe an automated image analysis method and discuss how to extract information from the generated quantitative time-course data.


Assuntos
Citometria de Fluxo/métodos , Proteínas de Homeodomínio/análise , Microscopia Confocal/métodos , Células-Tronco Embrionárias Murinas/citologia , Análise de Célula Única/métodos , Animais , Técnicas de Cultura de Células/métodos , Ciclo Celular , Linhagem Celular , Regulação da Expressão Gênica , Proteínas de Homeodomínio/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Proteína Homeobox Nanog , Imagem Óptica/métodos , Fatores de Tempo
13.
Genom Data ; 6: 77-80, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26697340

RESUMO

To gain new insights about the genetic networks controlling hair cell (HC) development, we previously developed a direct genetic programming strategy to generate an inexhaustible supply of HC-like cells (induced HCs, iHCs) in vitro, starting from mouse embryonic stem cells (ESC). We found that combined activity of three transcription factors, Gfi1, Pou4f3, and Atoh1, can program ESC-derived progenitors towards HC fate with efficiencies of 55%-80%. These iHCs express several HC markers and exhibit polarized structures that are highly reminiscent of the mechanosensitive hair bundles, with many microvilli-like stereocilia. Here, we describe the experimental design, methodology, and data validation for the microarray analysis used to characterize the transcriptome profile of iHCs at different stages of their differentiation. This approach based on FACS sorting and microarray analysis revealed a highly similar iHC transcriptome to that of endogenous HCs in vivo. The data obtained in this study is available in the Gene Expression Omnibus (GEO) database (accession number GSE60352).

14.
Development ; 142(17): 2864-75, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26329597

RESUMO

Neuromesodermal progenitors (NMps) contribute to both the elongating spinal cord and the adjacent paraxial mesoderm. It has been assumed that these cells arise as a result of patterning of the anterior neural plate. However, as the molecular mechanisms that specify NMps in vivo are uncovered, and as protocols for generating these bipotent cells from mouse and human pluripotent stem cells in vitro are established, the emerging data suggest that this view needs to be revised. Here, we review the characteristics, regulation, in vitro derivation and in vivo induction of NMps. We propose that these cells arise within primitive streak-associated epiblast via a mechanism that is separable from that which establishes neural fate in the anterior epiblast. We thus argue for the existence of two distinct routes for making central nervous system progenitors.


Assuntos
Mesoderma/citologia , Medula Espinal/citologia , Medula Espinal/embriologia , Células-Tronco/citologia , Animais , Padronização Corporal , Embrião de Mamíferos/citologia , Humanos , Células-Tronco Neurais/citologia , Transdução de Sinais
15.
Sci Rep ; 5: 13339, 2015 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-26292941

RESUMO

Populations of cultured mouse embryonic stem cells (ESCs) exhibit a subfraction of cells expressing uncharacteristically low levels of pluripotency markers such as Nanog. Yet, the extent to which individual Nanog-negative cells are differentiated, both from ESCs and from each other, remains unclear. Here, we show the transcriptome of Nanog-negative cells exhibits expression of classes of genes associated with differentiation that are not yet active in cells exposed to differentiation conditions for one day. Long non-coding RNAs, however, exhibit more changes in expression in the one-day-differentiated cells than in Nanog-negative cells. These results are consistent with the concept that Nanog-negative cells may contain subpopulations of both lineage-primed and differentiated cells. Single cell analysis showed that Nanog-negative cells display substantial and coherent heterogeneity in lineage marker expression in progressively nested subsets of cells exhibiting low levels of Nanog, then low levels of Oct4, and then a set of lineage markers, which express intensely in a small subset of these more differentiated cells. Our results suggest that the observed enrichment of lineage-specific marker gene expression in Nanog-negative cells is associated with spontaneous differentiation of a subset of these cells rather than the more random expression that may be associated with reversible lineage priming.


Assuntos
Biomarcadores/metabolismo , Diferenciação Celular , Linhagem da Célula , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Linhagem da Célula/genética , Perfilação da Expressão Gênica , Genoma , Proteínas de Homeodomínio/metabolismo , Hibridização in Situ Fluorescente , Camundongos , Proteína Homeobox Nanog , Ligação Proteica , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Análise de Célula Única , Fatores de Transcrição/metabolismo , Transcriptoma/genética
16.
Biotechnol J ; 10(10): 1578-88, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26123315

RESUMO

Standardization of culture methods for human pluripotent stem cell (PSC) neural differentiation can greatly contribute to the development of novel clinical advancements through the comprehension of neurodevelopmental diseases. Here, we report an approach that reproduces neural commitment from human induced pluripotent stem cells using dual-SMAD inhibition under defined conditions in a vitronectin-based monolayer system. By employing this method it was possible to obtain neurons derived from both control and Rett syndrome patients' pluripotent cells. During differentiation mutated cells displayed alterations in the number of neuronal projections, and production of Tuj1 and MAP2-positive neurons. Although investigation of a broader number of patients would be required, these observations are in accordance with previous studies showing impaired differentiation of these cells. Consequently, our experimental methodology was proved useful not only for the generation of neural cells, but also made possible to compare neural differentiation behavior of different cell lines under defined culture conditions. This study thus expects to contribute with an optimized approach to study the neural commitment of human PSCs, and to produce patient-specific neural cells that can be used to gain a better understanding of disease mechanisms.


Assuntos
Técnicas de Cultura de Células/métodos , Diferenciação Celular/genética , Células-Tronco Pluripotentes Induzidas/citologia , Neurogênese , Síndrome de Rett/genética , Linhagem Celular , Proliferação de Células/genética , Meios de Cultura , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Proteína 2 de Ligação a Metil-CpG/biossíntese , Proteína 2 de Ligação a Metil-CpG/genética , Células-Tronco Neurais/citologia , Neurônios/citologia , Síndrome de Rett/patologia , Síndrome de Rett/terapia , Proteínas Smad Inibidoras/genética
17.
PLoS Genet ; 11(6): e1005328, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26114479

RESUMO

Notch signalling is a fundamental pathway that shapes the developing embryo and sustains adult tissues by direct communication between ligand and receptor molecules on adjacent cells. Among the ligands are two Delta paralogues, DLL1 and DLL4, that are conserved in mammals and share a similar structure and sequence. They activate the Notch receptor partly in overlapping expression domains where they fulfil redundant functions in some processes (e.g. maintenance of the crypt cell progenitor pool). In other processes, however, they appear to act differently (e.g. maintenance of foetal arterial identity) raising the questions of how similar DLL1 and DLL4 really are and which mechanism causes the apparent context-dependent divergence. By analysing mice that conditionally overexpress DLL1 or DLL4 from the same genomic locus (Hprt) and mice that express DLL4 instead of DLL1 from the endogenous Dll1 locus (Dll1Dll4ki), we found functional differences that are tissue-specific: while DLL1 and DLL4 act redundantly during the maintenance of retinal progenitors, their function varies in the presomitic mesoderm (PSM) where somites form in a Notch-dependent process. In the anterior PSM, every cell expresses both Notch receptors and ligands, and DLL1 is the only activator of Notch while DLL4 is not endogenously expressed. Transgenic DLL4 cannot replace DLL1 during somitogenesis and in heterozygous Dll1Dll4ki/+ mice, the Dll1Dll4ki allele causes a dominant segmentation phenotype. Testing several aspects of the complex Notch signalling system in vitro, we found that both ligands have a similar trans-activation potential but that only DLL4 is an efficient cis-inhibitor of Notch signalling, causing a reduced net activation of Notch. These differential cis-inhibitory properties are likely to contribute to the functional divergence of DLL1 and DLL4.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/metabolismo , Receptores Notch/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas de Ligação ao Cálcio , Extremidades/embriologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Mesoderma/metabolismo , Camundongos Transgênicos , Estrutura Terciária de Proteína , Retina/embriologia , Transdução de Sinais
18.
Development ; 142(11): 1948-59, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26015538

RESUMO

Mechanosensory hair cells (HCs) are the primary receptors of our senses of hearing and balance. Elucidation of the transcriptional networks regulating HC fate determination and differentiation is crucial not only to understand inner ear development but also to improve cell replacement therapies for hearing disorders. Here, we show that combined expression of the transcription factors Gfi1, Pou4f3 and Atoh1 can induce direct programming towards HC fate, both during in vitro mouse embryonic stem cell differentiation and following ectopic expression in chick embryonic otic epithelium. Induced HCs (iHCs) express numerous HC-specific markers and exhibit polarized membrane protrusions reminiscent of stereociliary bundles. Transcriptome profiling confirms the progressive establishment of a HC-specific gene signature during in vitro iHC programming. Overall, this work provides a novel approach to achieve robust and highly efficient HC production in vitro, which could be used as a model to study HC development and to drive inner ear HC regeneration.


Assuntos
Reprogramação Celular , Células Ciliadas Auditivas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Linhagem da Célula/efeitos dos fármacos , Linhagem da Célula/genética , Forma Celular/efeitos dos fármacos , Reprogramação Celular/efeitos dos fármacos , Embrião de Galinha , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/ultraestrutura , Fluorescência , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genes Reporter , Células Ciliadas Auditivas/citologia , Células Ciliadas Auditivas/efeitos dos fármacos , Camundongos , Receptores Notch/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/genética , Tretinoína/farmacologia
19.
PLoS One ; 9(11): e113365, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25412258

RESUMO

In a previous study we identified active Notch signaling in key cellular events occurring at adult spermatogenesis. In this study, we evaluated the function of Notch signaling in spermatogenesis through the effects of in vivo Notch blockade. Adult CD1 male mice were either submitted to a long term DAPT (?-secretase inhibitor) or vehicle treatment. Treatment duration was designed to attain one half the time (25 days) or the time (43 days) required to accomplish a complete cycle of spermatogenesis. Blockade of Notch signaling was depicted from decreased transcription of Notch effector genes. Notch signaling blockade disrupted the expression patterns of Notch components in the testis, induced male germ cell fate aberrations, and significantly increased germ cell apoptosis, mainly in the last stages of the spermatogenic cycle, and epididymis spermatozoa morphological defects. These effects were more pronounced following the 43 day than the 25 day DAPT treatment schedule. These results indicate a relevant regulatory role of Notch signaling in mammalian spermatogenesis.


Assuntos
Dipeptídeos/farmacologia , Receptores Notch/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Espermatogênese/efeitos dos fármacos , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Epididimo/metabolismo , Epididimo/patologia , Células Germinativas/citologia , Células Germinativas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Proteínas/genética , Proteínas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores Notch/metabolismo , Fatores de Transcrição HES-1
20.
Development ; 141(14): 2770-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25005472

RESUMO

Heterogeneous expression of the transcription factor NANOG has been linked to the existence of various functional states in pluripotent stem cells. This heterogeneity seems to arise from fluctuations of Nanog expression in individual cells, but a thorough characterization of these fluctuations and their impact on the pluripotent state is still lacking. Here, we have used a novel fluorescent reporter to investigate the temporal dynamics of NANOG expression in mouse embryonic stem cells (mESCs), and to dissect the lineage potential of mESCs at different NANOG states. Our results show that stochastic NANOG fluctuations are widespread in mESCs, with essentially all expressing cells showing fluctuations in NANOG levels, even when cultured in ground-state conditions (2i media). We further show that fluctuations have similar kinetics when mESCs are cultured in standard conditions (serum plus leukemia inhibitory factor) or ground-state conditions, implying that NANOG fluctuations are inherent to the pluripotent state. We have then compared the developmental potential of low-NANOG and high-NANOG mESCs, grown in different conditions, and confirm that mESCs are more susceptible to enter differentiation at the low-NANOG state. Further analysis by gene expression profiling reveals that low-NANOG cells have marked expression of lineage-affiliated genes, with variable profiles according to the signalling environment. By contrast, high-NANOG cells show a more stable expression profile in different environments, with minimal expression of lineage markers. Altogether, our data support a model in which stochastic NANOG fluctuations provide opportunities for mESCs to explore multiple lineage options, modulating their probability to change functional state.


Assuntos
Células-Tronco Embrionárias/metabolismo , Proteínas de Homeodomínio/metabolismo , Células-Tronco Pluripotentes/metabolismo , Animais , Linhagem Celular , Linhagem da Célula/genética , Proliferação de Células , Células Clonais , Células-Tronco Embrionárias/citologia , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio/genética , Cinética , Camundongos , Proteína Homeobox Nanog , Células-Tronco Pluripotentes/citologia , Análise de Componente Principal , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Processos Estocásticos , Imagem com Lapso de Tempo , Transcrição Gênica
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