292 research outputs found

    Safety assessment of Mentha mozaffarianii essential oil: Acute and repeated toxicity studies

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    Background: Mentha mozaffarianii, an endemic species from the Labiatae family, is used in Iranian traditional medicine. This study evaluated the acute and repeated oral toxicity of the Mentha mozaffarianii essential oil (MMEO) in rats and mice. Methods: To assess the toxicity profile of the MMEO, we administered the essential oil to 48 rats and mice of both sexes by gavage in acute and repeated models. In acute toxicity, the animals were administered the MMEO (2000 mg/kg) and were monitored for 14 days. In the repeated toxicity, the MMEO was administered (100 mg/kg) daily for 4 weeks. On the 28th day, all the animals were scarified and blood and tissue samples were prepared. All the clinical, biochemical, and histopathological changes were assessed and compared with those in the controls. Statistical significance was determined by one- and two-way analyses of variance, followed by the Tukey test using GraphPad Prism 6. Results: In the acute test, there was no mortality; therefore, the oral LD50 value determined in the mice and rats of both sexes was greater than 2000 mg/kg. In the repeated test, the animals received the MMEO and there was no mortality. In the biochemical analysis, there were significant increases in blood glucose, cholesterol, ALT, AST, ALP, and TSH in the female rats and also in BUN in the male rats. The histopathological studies revealed evidence of microscopic lesions in the liver, kidney, stomach, and small intestine tissues of the MMEO group. Conclusion: The results indicated that the acute toxicity of the MMEO in the mice and rats was of a low order and it revealed slight tissue damage to several organs when given subchronically at a dose of 100 mg/kg. © 2018, Shiraz University of Medical Sciences. All rights reserved

    Ricci flat rotating black branes with a conformally invariant Maxwell source

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    We consider Einstein gravity coupled to an U(1)U(1) gauge field for which the density is given by a power of the Maxwell Lagrangian. In dd-dimensions the action of Maxwell field is shown to enjoy the conformal invariance if the power is chosen as d/4d/4. We present a class of charge rotating solutions in Einstein-conformally invariant Maxwell gravity in the presence of a cosmological constant. These solutions may be interpreted as black brane solutions with inner and outer event horizons or an extreme black brane depending on the value of the mass parameter. Since we are considering power of the Maxwell density, the black brane solutions exist only for dimensions which are multiples of four. We compute conserved and thermodynamics quantities of the black brane solutions and show that the expression of the electric field does not depend on the dimension. Also, we obtain a Smarr-type formula and show that these conserved and thermodynamic quantities of black branes satisfy the first law of thermodynamics. Finally, we study the phase behavior of the rotating black branes and show that there is no Hawking--Page phase transition in spite of conformally invariant Maxwell field.Comment: 13 pages, one figur

    Molecular description of eye defects in the zebrafish pax6b mutant, sunrise, reveals a pax6b-dependent genetic network in the developing anterior chamber

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    The cornea is a central component of the camera eye of vertebrates and even slight corneal disturbances severely affect vision. The transcription factor PAX6 is required for normal eye development, namely the proper separation of the lens from the developing cornea and the formation of the iris and anterior chamber. Human PAX6 mutations are associated with severe ocular disorders such as aniridia, Peters anomaly and chronic limbal stem cell insufficiency. To develop the zebrafish as a model for corneal disease, we first performed transcriptome and in situ expression analysis to identify marker genes to characterise the cornea in normal and pathological conditions. We show that, at 7 days post fertilisation (dpf), the zebrafish cornea expresses the majority of marker genes (67/84 tested genes) found also expressed in the cornea of juvenile and adult stages. We also characterised homozygous pax6b mutants. Mutant embryos have a thick cornea, iris hypoplasia, a shallow anterior chamber and a small lens. Ultrastructure analysis revealed a disrupted corneal endothelium. pax6b mutants show loss of corneal epithelial gene expression including regulatory genes (sox3, tfap2a, foxc1a and pitx2). In contrast, several genes (pitx2, ctnnb2, dcn and fabp7a) were ectopically expressed in the malformed corneal endothelium. Lack of pax6b function leads to severe disturbance of the corneal gene regulatory programme

    Melanosomes in pigmented epithelia maintain eye lens transparency during zebrafish embryonic development

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    Altered levels of trace elements are associated with increased oxidative stress that is eventually responsible for pathologic conditions. Oxidative stress has been proposed to be involved in eye diseases, including cataract formation. We visualized the distribution of metals and other trace elements in the eye of zebrafish embryos by micro X-ray fluorescence (μ-XRF) imaging. Many elements showed highest accumulation in the retinal pigment epithelium (RPE) of the zebrafish embryo. Knockdown of the zebrafish brown locus homologues tyrp1a/b eliminated accumulation of these elements in the RPE, indicating that they are bound by mature melanosomes. Furthermore, albino (slc45a2) mutants, which completely lack melanosomes, developed abnormal lens reflections similar to the congenital cataract caused by mutation of the myosin chaperon Unc45b, and an in situ spin trapping assay revealed increased oxidative stress in the lens of albino mutants. Finally transplanting a wildtype lens into an albino mutant background resulted in cataract formation. These data suggest that melanosomes in pigment epithelial cells protect the lens from oxidative stress during embryonic development, likely by buffering trace elements

    Phenotype instability of hepatocyte-like cells produced by direct reprogramming of mesenchymal stromal cells

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    Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2020-05-20T13:36:52Z No. of bitstreams: 2 Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5) Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2020-05-20T14:09:16Z (GMT) No. of bitstreams: 2 Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5) Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5)Made available in DSpace on 2020-05-20T14:09:16Z (GMT). No. of bitstreams: 2 Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5) Orge Yasmin Diniz , Phenotype....pdf: 16650804 bytes, checksum: c3eb41edf819fec369deb1d2cfc161da (MD5) Previous issue date: 2020Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Universidade Federal da Bahia. Institute of Health Sciences. Salvador, BA, Brasil.MRC Centre for Regenerative Medicine. Edinburgh, UK.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil.MRC Centre for Regenerative Medicine. Edinburgh, UK.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil.Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / São Rafael Hospital. Center for Biotechnology and Cell Therapy, Salvador, BA, Brazil / D’Or Institute for Research and Education. Rio de Janeiro, RJ, Brazil / National Institute of Science and Technology for Regenerative Medicine. Rio de Janeiro, RJ, Brazil /Hepatocyte-like cells (iHEPs) generated by transcription factor-mediated direct reprogramming of somatic cells have been studied as potential cell sources for the development of novel therapies targeting liver diseases. The mechanisms involved in direct reprogramming, stability after long-term in vitro expansion, and safety profile of reprogrammed cells in different experimental models, however, still require further investigation. Methods: iHEPs were generated by forced expression of Foxa2/Hnf4a in mouse mesenchymal stromal cells and characterized their phenotype stability by in vitro and in vivo analyses. Results: The iHEPs expressed mixed hepatocyte and liver progenitor cell markers, were highly proliferative, and presented metabolic activities in functional assays. A progressive loss of hepatic phenotype, however, was observed after several passages, leading to an increase in alpha-SMA+ fibroblast-like cells, which could be distinguished and sorted from iHEPs by differential mitochondrial content. The resulting purified iHEPs proliferated, maintained liver progenitor cell markers, and, upon stimulation with lineage maturation media, increased expression of either biliary or hepatocyte markers. In vivo functionality was assessed in independent pre-clinical mouse models. Minimal engraftment was observed following transplantation in mice with acute acetaminophen-induced liver injury. In contrast, upon transplantation in a transgenic mouse model presenting host hepatocyte senescence, widespread engraftment and uncontrolled proliferation of iHEPs was observed, forming islands of epithelial-like cells, adipocytelike cells, or cells presenting both morphologies. Conclusion: The results have significant implications for cell reprogramming, suggesting that iHEPs generated by Foxa2/Hnf4a expression have an unstable phenotype and depend on transgene expression for maintenance of hepatocyte-like characteristics, showing a tendency to return to the mesenchymal phenotype of origin and a compromised safety profil

    MECP2 Isoform-Specific Vectors with Regulated Expression for Rett Syndrome Gene Therapy

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    BACKGROUND:Rett Syndrome (RTT) is an Autism Spectrum Disorder and the leading cause of mental retardation in females. RTT is caused by mutations in the Methyl CpG-Binding Protein-2 (MECP2) gene and has no treatment. Our objective is to develop viral vectors for MECP2 gene transfer into Neural Stem Cells (NSC) and neurons suitable for gene therapy of Rett Syndrome. METHODOLOGY/PRINCIPAL FINDINGS:We generated self-inactivating (SIN) retroviral vectors with the ubiquitous EF1alpha promoter avoiding known silencer elements to escape stem-cell-specific viral silencing. High efficiency NSC infection resulted in long-term EGFP expression in transduced NSC and after differentiation into neurons. Infection with Myc-tagged MECP2-isoform-specific (E1 and E2) vectors directed MeCP2 to heterochromatin of transduced NSC and neurons. In contrast, vectors with an internal mouse Mecp2 promoter (MeP) directed restricted expression only in neurons and glia and not NSC, recapitulating the endogenous expression pattern required to avoid detrimental consequences of MECP2 ectopic expression. In differentiated NSC from adult heterozygous Mecp2(tm1.1Bird)+/- female mice, 48% of neurons expressed endogenous MeCP2 due to random inactivation of the X-linked Mecp2 gene. Retroviral MECP2 transduction with EF1alpha and MeP vectors rescued expression in 95-100% of neurons resulting in increased dendrite branching function in vitro. Insulated MECP2 isoform-specific lentiviral vectors show long-term expression in NSC and their differentiated neuronal progeny, and directly infect dissociated murine cortical neurons with high efficiency. CONCLUSIONS/SIGNIFICANCE:MeP vectors recapitulate the endogenous expression pattern of MeCP2 in neurons and glia. They have utility to study MeCP2 isoform-specific functions in vitro, and are effective gene therapy vectors for rescuing dendritic maturation of neurons in an ex vivo model of RTT

    Expression of Wnt gene family and frizzled receptors in head and neck squamous cell carcinomas

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    [Abstract] Genes of the Wnt and Frizzled class, expressed in HNSCC tissue and cell lines, have an established role in cell morphogenesis and differentiation, and also they have oncogenic properties. We studied Wnt and Fz genes as potential tumor-associated markers in HNSCC by qPCR. Expression levels of Wnt and Fz genes in 22 unique frozen samples from HNSCC were measured. We also assessed possible correlation between the expression levels obtained in cancer samples in relation to clinicopathologic outcome. Wnt-1 was not expressed in the majority of the HNSCC studied, whereas Wnt-5A was the most strongly expressed by the malignant tumors. Wnt-10B expression levels were related with higher grade of undifferentiation. Related to Fz genes, Fz-5 showed more expression levels in no-affectation of regional lymph nodes. Kaplan–Meier survival analyses suggest a reduced time of survival for low and high expression of Wnt-7A and Fz-5 mRNA, respectively. qPCR demonstrated that HNSCC express Wnt and Fz members, and suggested that Wnt and Fz signaling is activated in HNSCC cells

    Integrated annotation and analysis of genomic features reveal new types of functional elements and large-scale epigenetic phenomena in the developing zebrafish

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    Zebrafish, a popular model for embryonic development and for modelling human diseases, has so far lacked a systematic functional annotation programme akin to those in other animal models. To address this, we formed the international DANIO-CODE consortium and created the first central repository to store and process zebrafish developmental functional genomic data. Our Data Coordination Center (https://danio-code.zfin.org) combines a total of 1,802 sets of unpublished and reanalysed published genomics data, which we used to improve existing annotations and show its utility in experimental design. We identified over 140,000 cis-regulatory elements in development, including novel classes with distinct features dependent on their activity in time and space. We delineated the distinction between regulatory elements active during zygotic genome activation and those active during organogenesis, identifying new aspects of how they relate to each other. Finally, we matched regulatory elements and epigenomic landscapes between zebrafish and mouse and predict functional relationships between them beyond sequence similarity, extending the utility of zebrafish developmental genomics to mammals

    Constitutively active Lyn kinase causes a cutaneous small vessel vasculitis and liver fibrosis syndrome

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    Neutrophilic inflammation is a hallmark of many monogenic autoinflammatory diseases; pathomechanisms that regulate extravasation of damaging immune cells into surrounding tissues are poorly understood. Here we identified three unrelated boys with perinatal-onset of neutrophilic cutaneous small vessel vasculitis and systemic inflammation. Two patients developed liver fibrosis in their first year of life. Next-generation sequencing identified two de novo truncating variants in the Src-family tyrosine kinase, LYN, p.Y508*, p.Q507* and a de novo missense variant, p.Y508F, that result in constitutive activation of Lyn kinase. Functional studies revealed increased expression of ICAM-1 on induced patient-derived endothelial cells (iECs) and of β2-integrins on patient neutrophils that increase neutrophil adhesion and vascular transendothelial migration (TEM). Treatment with TNF inhibition improved systemic inflammation; and liver fibrosis resolved on treatment with the Src kinase inhibitor dasatinib. Our findings reveal a critical role for Lyn kinase in modulating inflammatory signals, regulating microvascular permeability and neutrophil recruitment, and in promoting hepatic fibrosis
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