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1.
Entropy (Basel) ; 25(6)2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37372288

RESUMO

In this work, we explore the formalism of the irreversible thermodynamics of open systems and the possibility of gravitationally generated particle production in modified gravity. More specifically, we consider the scalar-tensor representation of f(R,T) gravity, in which the matter energy-momentum tensor is not conserved due to a nonminimal curvature-matter coupling. In the context of the irreversible thermodynamics of open systems, this non-conservation of the energy-momentum tensor can be interpreted as an irreversible flow of energy from the gravitational sector to the matter sector, which, in general, could result in particle creation. We obtain and discuss the expressions for the particle creation rate, the creation pressure, and the entropy and temperature evolutions. Applied together with the modified field equations of scalar-tensor f(R,T) gravity, the thermodynamics of open systems lead to a generalization of the ΛCDM cosmological paradigm, in which the particle creation rate and pressure are considered effectively as components of the cosmological fluid energy-momentum tensor. Thus, generally, modified theories of gravity in which these two quantities do not vanish provide a macroscopic phenomenological description of particle production in the cosmological fluid filling the Universe and also lead to the possibility of cosmological models that start from empty conditions and gradually build up matter and entropy.

2.
Data Brief ; 37: 107179, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34159238

RESUMO

This database is a geological and geochronological compilation made to study a small Archean/Paleoproterozoic block located in the centre of the Precambrian rock exposition of Uruguay. Petrographic and field outcrops data supporting the samples from which the zircons for textural analysis and U-Pb dating (LA-ICP-MS) come are presented at first with their descriptions. The first table (1) contains the new U-Pb isotopic data. The second table (2) presents a correlation of textures from different zircon samples. The last table (3) contains an inventory of different U-Pb ages found in antecedents. All these data are associated with the paper entitled: "The Archean Pavas Block in Uruguay: extension and tectonic evolution based on LA-ICP-MS U-Pb ages and airborne geophysics".

3.
J Physiol ; 598(18): 3911-3925, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32627185

RESUMO

KEY POINTS: In vascular smooth muscle cells (VSMCs), activation of Ca2+ -permeable store-operated channels (SOCs) composed of canonical transient receptor potential channel 1 (TRPC1) subunits mediates Ca2+ entry pathways that regulate contraction, proliferation and migration, which are processes associated with vascular disease. Activation of TRPC1-based SOCs requires protein kinase C (PKC) activity, which is proposed to phosphorylate TRPC1 proteins to promote channel opening by phosphatidylinositol 4,5-bisphosphate (PIP2 ). We investigated the identity of the PKC isoform involved in activating TRPC1-based SOCs in rat mesenteric artery VSMCs. TRPC1-based SOCs were reduced by PKCδ inhibitors and knockdown of PKCδ expression. Store depletion induced interactions between TRPC1 and PKCδ and PKCδ-dependent phosphorylation of TRPC1. Furthermore, generation of store-operated interactions between PIP2 and TRPC1 and activation of TRPC1-based SOCs by PIP2 required PKCδ. These findings reveal that PKCδ activity has an obligatory role in activating TRPC1-based SOCs, through regulating PIP2 -mediated channel opening. ABSTRACT: In vascular smooth muscle cells (VMSCs), stimulation of Ca2+ -permeable canonical transient receptor potential channel 1 (TRPC1)-based store-operated channels (SOCs) mediates Ca2+ entry pathways that regulate cell contraction, proliferation and migration, which are processes associated with vascular disease. It is therefore important to understand how TRPC1-based SOCs are activated. Stimulation of TRPC1-based SOCs requires protein kinase C (PKC) activity, with store-operated PKC-dependent phosphorylation of TRPC1 essential for channel opening by phosphatidylinositol 4,5-bisphosphate (PIP2 ). Experimental protocols used to activate TRPC1-based SOCs suggest that the PKC isoform involved requires diacylglycerol (DAG) but is Ca2+ -insensitive, which are characteristics of the novel group of PKC isoforms (δ, ε, η, θ). Hence, the present study examined whether a novel PKC isoform(s) is involved in activating TRPC1-based SOCs in contractile rat mesenteric artery VSMCs. Store-operated whole-cell cation currents were blocked by Pico145, a highly selective and potent TRPC1/4/5 channel blocker and T1E3, a TRPC1 blocking antibody. PKCδ was expressed in VSMCs, and selective PKCδ inhibitory peptides and knockdown of PKCδ expression with morpholinos oligomers inhibited TRPC1-based SOCs. TRPC1 and PKCδ interactions and phosphorylation of TRPC1 induced by store depletion were both reduced by pharmacological inhibition and PKCδ knockdown. In addition, store-operated PIP2 and TRPC1 interactions were blocked by PKCδ inhibition, and PKCδ was required for PIP2 -mediated activation of TRPC1 currents. These results identify the involvement of PKCδ in stimulation of TRPC1-based SOCs and highlight that store-operated PKCδ activity is obligatory for channel opening by PIP2 , the probable activating ligand.


Assuntos
Músculo Liso Vascular , Canais de Potencial de Receptor Transitório , Animais , Cálcio/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteína Quinase C/metabolismo , Ratos , Canais de Cátion TRPC
4.
Rev. colomb. cienc. pecu ; 33(2): 81-95, Apr.-June 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1289286

RESUMO

Abstract Background: Pregnancy in all animal species requires special care and attention. During this period there is great variation in hematological and biochemical parameters. Many times these parameters are misinterpreted as being obtained from non-pregnant animals with unknown parasite status. Objective: To characterize the hematological, biochemical, and parasitological values within the peripartum period of Santa Ines sheep naturally infected. Methods: For this purpose, 45 ewes were used, with an average body weight of 50 kg. Data were collected during pregnancy, birth and, lactation. Measurements included body weight, body condition score (BCS), evaluation of conjunctive staining, and collection of blood and feces. Results: All variables changed throughout physiological stages. Weight and BCS were different between periods (p<0.05). Fecal egg counts (FEC) were higher in the peripartum period, with a predominance of Haemonchus ssp, 92.85%. Mean hematological and biochemical values varied throughout the study, (p>0.05). Conclusion: The influence of peripartum on the parameters studied should be considered and its use as a reference value. Regarding the physiological variations observed during peripartum, proper animal management could help minimizing the negative effects of parasitic infections on productivity.


Resumen Antecedentes: La preñez en todas las especies animales requiere atención y cuidados especiales. En ese período existe gran variación en los parámetros hematológicos y bioquímicos. Muchas veces estos parámetros son interpretados erróneamente por ser obtenidos de animales no gestantes y con estatus parasitario desconocido. Objetivo: Caracterizar los valores hematológicos, bioquímicos y parasitológicos durante el periparto en ovejas Santa Inés infectadas naturalmente. Métodos: Se utilizaron 45 ovejas, con un peso corporal promedio de 50 kg. la recolección de muestras se realizó durante la gestación, el parto y la lactancia. Se evaluó el peso, la condición corporal, la tinción conjuntiva, y se recolectaron muestras de sangre y heces. Resultados: Todas las variables mostraron variaciones a lo largo de las etapas fisiológicas. La puntuación de peso y condición corporal (BCS) mostró diferencia entre períodos (p<0,05). Los recuentos de huevos fecales (FEC) tuvieron mayores promedios en el periparto, con predominio de Haemonchus ssp, 92,85%. Los valores medios hematológicos y bioquímicos variaron a lo largo del estudio (p<0,05). Conclusiones: Se recomienda considerar la influencia del periparto en los parámetros estudiados y su uso como valor de referencia. Con respecto a las variaciones fisiológicas observadas durante el periparto, el manejo adecuado de los animales podría ayudar a minimizar los efectos negativos de las infecciones parasitarias sobre la productividad.


Resumo Antecedentes: A prenhez em todas as espécies requer atenção e cuidados especiais. Neste período há grande variação dos parâmetros hematológicos e bioquímicos dos animais. Muitas vezes estes parâmetros são mal interpretados na realização de diagnósticos por serem baseados em parâmetros de animais saudáveis não gestantes, desconsiderando também a infecção parasitária. Objetivo: Caracterizar os valores hematológicos, bioquímicos e parasitológicos durante o periparto de ovelhas da raça Santa Inês naturalmente infectadas. Métodos: Foram utilizadas quarenta e cinco ovelhas, com peso corporal médio de 50 kg, os animais foram acompanhados durante a prenhez, parto e lactação. As análises compreendiam: pesagem, condição corporal, Famacha©, sangue e fezes. Resultados: Todas as variáveis apresentaram variações concomitantemente ao avanço da gestação, parto e lactação. O peso (PS) e o escore da condição corporal (ECC) apresentaram diferença estatística entre os períodos (p>0,05). As contagens de ovos por grama de fezes (FEC) apresentaram médias mais elevadas no periparto. Os valores hematológicos e bioquímicos também variaram (p>0,05). Conclusão: Devido ao resultado, sugere-se considerar a influência de periparto sobre os parâmetros estudados e a sua utilização como um valor de referência. Tendo em vista as variações fisiológicas devido o período do periparto e as infecções parasitárias o manejo dos animais deve ter como objetivo minimizar os impactos negativos na produção animal.

5.
Cells ; 9(1)2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31936855

RESUMO

In vascular smooth muscle cells (VMSCs), the stimulation of store-operated channels (SOCs) mediate Ca2+ influx pathways which regulate important cellular functions including contraction, proliferation, migration, and growth that are associated with the development of vascular diseases. It is therefore important that we understand the biophysical, molecular composition, activation pathways, and physiological significance of SOCs in VSMCs as these maybe future therapeutic targets for conditions such as hypertension and atherosclerosis. Archetypal SOCs called calcium release-activated channels (CRACs) are composed of Orai1 proteins and are stimulated by the endo/sarcoplasmic reticulum Ca2+ sensor stromal interaction molecule 1 (STIM1) following store depletion. In contrast, this review focuses on proposals that canonical transient receptor potential (TRPC) channels composed of a heteromeric TRPC1/C5 molecular template, with TRPC1 conferring activation by store depletion, mediate SOCs in native contractile VSMCs. In particular, it summarizes our recent findings which describe a novel activation pathway of these TRPC1-based SOCs, in which protein kinase C (PKC)-dependent TRPC1 phosphorylation and phosphatidylinositol 4,5-bisphosphate (PIP2) are obligatory for channel opening. This PKC- and PIP2-mediated gating mechanism is regulated by the PIP2-binding protein myristoylated alanine-rich C kinase (MARCKS) and is coupled to store depletion by TRPC1-STIM1 interactions which induce Gq/PLCß1 activity. Interestingly, the biophysical properties and activation mechanisms of TRPC1-based SOCs in native contractile VSMCs are unlikely to involve Orai1.


Assuntos
Músculo Liso Vascular/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Humanos
6.
Molecules ; 25(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861795

RESUMO

Tumor cells have specific features, including angiogenesis induction, cell cycle dysregulation, and immune destruction evasion. By inducing a T helper type 2 (Th2) immune response, tumor cells may favor immune tolerance within the tumor, which allows progression of cancer growth. Drugs with potential antitumor activity are the spiro-acridines, which is a promising new class of acridine compounds. Herein, the novel spiro-acridine (E)-5'-oxo-1'-((3,4,5-trimethoxybenzylidene)amino)-1',5'-dihydro-10H-spiro[acridine-9,2'-pyrrole]-4'-carbonitrile (AMTAC-17) was synthesized and tested for antitumor effects. Toxicity evaluation was performed in mice after acute treatment (2000 mg/kg, intraperitoneally, i.p.). The Ehrlich ascites carcinoma model was used to investigate the antitumor activity of AMTAC-17 (12.5, 25, or 50 mg/kg, i.p.) after seven days of treatment. Effects on the cell cycle, angiogenesis, and inflammatory responses were investigated. LD50 (lethal dose 50%) was estimated to be higher than 5000 mg/kg. AMTAC-17 reduced the Ehrlich tumor's total viable cancer cells count and peritumoral micro-vessels density, and induced an increase in the sub-G1 peak. Additionally, there was an increase of Th1 cytokine profile levels (IL-1ß, TNF-α, and IL-12). In conclusion, the spiro-acridine compound AMTAC-17 presents low toxicity, and its in vivo antitumor effect involves modulation of the immune system to a cytotoxic Th1 profile and a reduction of tumor angiogenesis.


Assuntos
Acridinas , Inibidores da Angiogênese , Antineoplásicos , Carcinoma de Ehrlich , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Th1/imunologia , Regulação para Cima/efeitos dos fármacos , Acridinas/química , Acridinas/farmacologia , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Carcinoma de Ehrlich/tratamento farmacológico , Carcinoma de Ehrlich/imunologia , Carcinoma de Ehrlich/patologia , Regulação Neoplásica da Expressão Gênica/imunologia , Camundongos , Células Th1/patologia , Regulação para Cima/imunologia
7.
Arq Bras Cardiol ; 113(5): 1006-1056, 2019 11.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31800728
8.
Methods Mol Biol ; 1742: 37-44, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29330788

RESUMO

Here we describe a simple method based on secreted luciferase driven by a hypoxia-inducible factor (HIF) response element (HRE) that allows the acquisition of dynamic and high-throughput data on HIF transcriptional activity during hypoxia and pharmacological activation of HIF. The sensitivity of the assay allows for the secreted luciferase to be consecutively sampled (as little as 1% of the total supernatant) over an extended time period, thus allowing the acquisition of time-resolved HIF transcriptional activity.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Luciferases/genética , Elementos de Resposta , Aminoácidos Dicarboxílicos/metabolismo , Hipóxia Celular , Células HEK293 , Humanos , Regiões Promotoras Genéticas , Proteínas Recombinantes , Ativação Transcricional
9.
Ultrasonics ; 82: 153-160, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28822330

RESUMO

We analyze experimentally and theoretically the sound propagation velocity of P-waves in granular media made of micrometer-size magnetite particles under an external magnetic field. The sound velocity is measured in a coherent (long-wavelength) regime of propagation after a controlled sample preparation consisting of a fluidization and the application of a magnetic field. Several different procedures are applied and result in different but reproducible particle arrangements and preferential contact orientations affecting the measured sound velocity. Interestingly, we find that the sound velocity increases when the magnetic field is applied parallel to the sound propagation direction and decreases when the magnetic field is applied perpendicular to the sound propagation direction. The observed qualitative relationship between the changes in the particle arrangement and the sound velocity is analyzed theoretically based on an effective medium theory adapted to account for the effect of the magnetic field in the preparation procedure and its influence on the medium contact fabric.

10.
PLoS One ; 12(10): e0185664, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28968430

RESUMO

Stroke causes severe neuronal damage as disrupted cerebral blood flow starves neurons of oxygen and glucose. The hypoxia inducible factors (HIF-1α and HIF-2α) orchestrate oxygen homeostasis and regulate specific aspects of hypoxic adaptation. Here we show the importance of HIF-2α dependant signalling in neuronal adaptation to hypoxic insult. PC12 and NT2 cells were differentiated into neuronal-like cells using NGF and retinoic acid, and exposed to acute hypoxia (1% O2). Gene and protein expression was analysed by qPCR and immunoblotting and the neuronal-like phenotype was examined. PC12 and NT2 differentiation promoted neurite extension and expression of neuronal markers, NSE and KCC2. Induction of HIF-1α mRNA or protein was not detected in hypoxic neuronal-like cells, however marked induction of HIF-2α mRNA and protein expression was observed. Induction of HIF-1α target genes was also not detected in response to acute hypoxia, however significant induction of HIF-2α transcriptional targets was clearly evident. Furthermore, hypoxic insult dramatically reduced both neurite number and length, and attenuated expression of neuronal markers, NSE and KCC2. This correlated with an increase in expression of the neural progenitor and stem cell-like markers, CD44 and vimentin, suggesting HIF-2α molecular mechanisms could potentially promote regression of neuronal-like cells to a stem-like state and trigger neuronal recovery following ischaemic insult. Our findings suggest the HIF-2α pathway predominates over HIF-1α signalling in neuronal-like cells following acute hypoxia.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipóxia Celular , Neurônios/metabolismo , Transdução de Sinais , Adaptação Fisiológica , Animais , Diferenciação Celular , Estresse do Retículo Endoplasmático , Humanos , Células-Tronco Neurais/metabolismo , Neurônios/citologia , Estabilidade Proteica , Ratos , Reação em Cadeia da Polimerase em Tempo Real
11.
Exp Cell Res ; 356(2): 173-181, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28219680

RESUMO

A sufficient supply molecular oxygen is essential for the maintenance of physiologic metabolism and bioenergetic homeostasis for most metazoans. For this reason, mechanisms have evolved for eukaryotic cells to adapt to conditions where oxygen demand exceeds supply (hypoxia). These mechanisms rely on the modification of pre-existing proteins, translational arrest and transcriptional changes. The hypoxia inducible factor (HIF; a master regulator of gene induction in response to hypoxia) is responsible for the majority of induced gene expression in hypoxia. However, much less is known about the mechanism(s) responsible for gene repression, an essential part of the adaptive transcriptional response. Hypoxia-induced gene repression leads to a reduction in energy demanding processes and the redirection of limited energetic resources to essential housekeeping functions. Recent developments have underscored the importance of transcriptional repressors in cellular adaptation to hypoxia. To date, at least ten distinct transcriptional repressors have been reported to demonstrate sensitivity to hypoxia. Central among these is the Repressor Element-1 Silencing Transcription factor (REST), which regulates over 200 genes. In this review, written to honor the memory and outstanding scientific legacy of Lorenz Poellinger, we provide an overview of our existing knowledge with respect to transcriptional repressors and their target genes in hypoxia.


Assuntos
Hipóxia Celular/fisiologia , Regulação da Expressão Gênica/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Transcrição Gênica/fisiologia , Animais , Humanos , Hipóxia/genética , Oxigênio/metabolismo
12.
J Neurochem ; 140(2): 195-209, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27861901

RESUMO

Stroke is one of the major causes of death and disability worldwide. The major type of stroke is an ischaemic one, which is caused by a blockage that interrupts blood flow to the brain. There are currently very few pharmacological strategies to reduce the damage and social burden triggered by this pathology. The harm caused by the interruption of blood flow to the brain unfolds in the subsequent hours and days, so it is critical to identify new therapeutic targets that could reduce neuronal death associated with the spread of the damage. Here, we review some of the key molecular mechanisms involved in the progression of neuronal death, focusing on some new and promising studies. In particular, we focus on the potential of the chloride co-transporter (CCC) family of proteins, mediators of the GABAergic response, both during the early and later stages of stroke, to promote neuroprotection and recovery. Different studies of CCCs during the chronic and recovery phases post-stroke reveal the importance of timing when considering CCCs as potential neuroprotective and/or neuromodulator targets. The molecular regulatory mechanisms of the two main neuronal CCCs, NKCC1 and KCC2, are further discussed as an indirect approach for promoting neuroprotection and neurorehabilitation following an ischaemic insult. Finally, we mention the likely importance of combining different strategies in order to achieve more effective therapies.


Assuntos
Encéfalo/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Cloretos/metabolismo , Fármacos Neuroprotetores/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Simportadores/farmacologia , Animais , Humanos
13.
Sci Rep ; 6: 31355, 2016 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-27531581

RESUMO

Cellular exposure to hypoxia results in altered gene expression in a range of physiologic and pathophysiologic states. Discrete cohorts of genes can be either up- or down-regulated in response to hypoxia. While the Hypoxia-Inducible Factor (HIF) is the primary driver of hypoxia-induced adaptive gene expression, less is known about the signalling mechanisms regulating hypoxia-dependent gene repression. Using RNA-seq, we demonstrate that equivalent numbers of genes are induced and repressed in human embryonic kidney (HEK293) cells. We demonstrate that nuclear localization of the Repressor Element 1-Silencing Transcription factor (REST) is induced in hypoxia and that REST is responsible for regulating approximately 20% of the hypoxia-repressed genes. Using chromatin immunoprecipitation assays we demonstrate that REST-dependent gene repression is at least in part mediated by direct binding to the promoters of target genes. Based on these data, we propose that REST is a key mediator of gene repression in hypoxia.


Assuntos
Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Análise de Sequência de RNA/métodos , Transcrição Gênica , Hipóxia Celular , Linhagem Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Células HEK293 , Humanos , Regiões Promotoras Genéticas , Transdução de Sinais
14.
Aquat Toxicol ; 177: 146-55, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27286572

RESUMO

Understanding the mechanism of phenanthrene (PHE) biotransformation and related cellular responses in bivalves can be an important tool to elucidate the risks of polycyclic aromatic hydrocarbons (PAHs) to aquatic organisms. In the present study it was analyzed the transcriptional levels of 13 biotransformation genes related to cytochrome P450 (CYP), glutathione S-transferase (GST), sulfotransferase (SULT), flavin-containing monooxygenase and fatty acid-binding proteins by qPCR in gill of scallops Nodipecten nodosus exposed for 24 or 96h to 50 or 200µgL(-1) PHE (equivalent to 0.28 and 1.12µM, respectively), followed by depuration in clean water for 96h (DEP). Likewise, it was quantified the activity of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione reductase (GR), glucose 6-phosphate dehydrogenase (G6PDH), GST and levels of lipid peroxidation. Increased transcriptional levels of CYP2UI-like, CYP2D20-like, CYP3A11-like, GSTomega-like, SULT1B1-like genes were detected in organisms exposed to PHE for 24 or 96h. In parallel, GR and GPX activities increased after 96h exposure to 200µgL(-1) PHE and G6PDH activity increased after 24h exposure to 50µgL(-1) PHE. This enhancement of antioxidant and phase I and II biotransformation systems may be related to the 2.7 and 12.5 fold increases in PHE bioaccumulation after 96h exposure to 50 and 200µgL(-1) PHE, respectively. Interestingly, DEP caused reestablishment of GPX and GR activity, as well as to the transcript levels of all upregulated biotransformation genes (except for SULT1B1-like). Bioaccumulated PHE levels decreased 2.5-2.9 fold after depuration, although some biochemical and molecular modifications were still present. Lipid peroxidation levels remained lower in animals exposed to 200µgL(-1) PHE for 24h and DEP. These data indicate that N. nodosus is able to induce an antioxidant and biotransformation-related response to PHE exposure, counteracting its toxicity, and DEP can be an effective protocol for bivalve depuration after PHE exposure.


Assuntos
Brânquias/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Pectinidae/efeitos dos fármacos , Fenantrenos/toxicidade , Transcrição Gênica/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Biotransformação/efeitos dos fármacos , Biotransformação/genética , Relação Dose-Resposta a Droga , Brânquias/metabolismo , Peroxidação de Lipídeos/genética , Pectinidae/genética , Pectinidae/metabolismo , Fenantrenos/metabolismo , Testes de Toxicidade , Poluentes Químicos da Água/metabolismo
15.
Pesqui. vet. bras ; 36(supl.1): 15-20, June 2016. tab
Artigo em Português | LILACS, VETINDEX | ID: lil-798012

RESUMO

O objetivo deste estudo foi avaliar o perfil hematológico de cabras da raça Saanen em diferentes fases da gestação e no pós-parto. Para sua realização foram utilizadas 24 cabras gestantes e 10 não gestantes da raça Saanen, criadas em condições intensivas no município de Alegre, Espírito Santo. As amostras foram coletadas dos 60 aos 135 dias de gestação, com intervalos de 15 dias entre as coletas. Após a parição foram realizadas mais duas coletas, também com intervalos de 15 dias. As amostras de sangue coletadas foram refrigeradas até a chegada ao laboratório, onde foi realizado o eritrograma e a leucometria global em analisador automático e as contagens diferenciais em esfregaço sanguíneo. Após análise dos resultados pode-se observar que, nas cabras avaliadas, houve influência do período de gestação, do pós-parto e da ordem de parto sobre os valores do eritrograma. Todos parâmetros avaliados, exceto VGM, diminuiram com o avançar da gestação até os quinze dias pós-parto, sendo que as maiores alterações ocorreram no final da gestação. A leucometria global (LG) e específica também apresentaram diferenças significativas de acordo com o estado fisiológicos das fêmeas. Os valores médios de LG foram de 10.579 a 15.836 leucócitos/mm3. Fêmeas não gestantes apresentaram maiores valores de LG, diminuindo com a gestação até os 15 dias do pós-parto. Trinta dias pós-parto o valor de LG aumentou, assemelhando-se aos valores das cabras não gestantes. Os valores absolutos de neutrófilos segmentados seguiram a mesma tendência da LG. A quantidade de linfócitos apresentou diminuição a partir dos 120 dias de gestação, aumentando a partir dos trinta dias pós-parto. A quantidade de eosinófilos não sofreu alteração de acordo com o estado fisiológico e a quantidade de basófilos foi maior em fêmeas não gestantes. Para monócitos os resultados foram em geral superiores nas cabras não gestantes e com 120 a 135 dias de gestação. Com relação a ordem de parição observou-se que fêmeas com mais de quatro partos apresentaram menores valores de VG, não havendo diferenças nos outros parâmetros do eritrograma. A LG foi maior na cabras com quatro partos, principalmente devido ao aumento de neutrófilos, enquanto que a quantidade de linfócitos foi menor nestas cabras. Os resultados encontrados evidenciaram a influência da gestação, do pós-parto e da ordem de parto das fêmeas da raça Saanen estudadas sobre os parâmetros hematológicos e também a necessidade da realização de estudos para se determinar os valores de referência do hemograma dos caprinos para cada tipo de criação, estado fisiológico e raça.(AU)


The aim of this study was to evaluate the hematological profile of Saanen goats at different stage of pregnancy and postpartum. For this study were uses 24 pregnant goats and 10 non-pregnant Saanen raised in intensive conditions in the Alegre city, Espirito Santo state. Samples were collected from 60 to 135 days of gestation, with intervals of 15 days between collections. After parturition were performed two more collections, also with intervals of 15 days. The blood samples were refrigerated until arrival at the laboratory. It was possible to perform the red blood cell (RBC) count, packed cell volume (PCV), hemoglobin, mean cell volume (MCV), mean corpuscular hemoglobin concentration (MCHC) and the white blood cell (WBC) count, on an automatic analyzer and the blood smears were stained whit panoptic stain for differential WBC counts. After analyzing results it can be seen that in goats assessed no influence of gestation, delivery and postpartum on the order of the values of the erythrocyte. All evaluated parameters except MCV, decreased with advancing gestation until fifteen days after birth, with the largest changes occurred in late pregnancy. The WBC and differential also showed significant differences according to the physiological stage of the females. The average values of WBC were 10579 e 15836 leukocytes/mm3. Non pregnant females showed higher WBC, with decreasing gestation until 15 days of postpartum. Thirty days postpartum increased the value of WBC, resembling the values of non-pregnant goats. The absolute values of segmented neutrophils followed the same trend of WBC. the number of lymphocytes showed decrease a 120 days of pregnancy, increasing from thirty days postpartum. The number of eosinophil was not changed according to the physiological state and the number of basophils was higher in non-pregnant females. For monocytes results were generally higher in non-pregnant goats and 120-135 days of gestation. With respect to parity other was observed that females with more than four birth a lower values of PVC, there were no differences in the other parameters of the erythrocyte. WBC was higher in goats with four deliveries, mainly due the increase of neutrophils, whereas the number of lymphocytes was lower in these goats. Already the number of lymphocytes was lower in goats with four birth. The results showed the influence of pregnancy, postpartum and the order of birth of the Saanen females studied on the hematological parameters and the need for studies to determine references values of blood cell counts for each type of goats breed.(AU)


Assuntos
Animais , Feminino , Gravidez , Contagem de Eritrócitos/veterinária , Cabras/sangue , Cabras/fisiologia , Contagem de Leucócitos/veterinária , Período Pós-Parto/sangue , Testes Hematológicos/veterinária , Padrões de Referência
16.
J Biol Chem ; 291(22): 11800-8, 2016 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-27044749

RESUMO

Molecular oxygen and carbon dioxide are the primary gaseous substrate and product of oxidative metabolism, respectively. Hypoxia (low oxygen) and hypercapnia (high carbon dioxide) are co-incidental features of the tissue microenvironment in a range of pathophysiologic states, including acute and chronic respiratory diseases. The hypoxia-inducible factor (HIF) is the master regulator of the transcriptional response to hypoxia; however, little is known about the impact of hypercapnia on gene transcription. Because of the relationship between hypoxia and hypercapnia, we investigated the effect of hypercapnia on the HIF pathway. Hypercapnia suppressed HIF-α protein stability and HIF target gene expression both in mice and cultured cells in a manner that was at least in part independent of the canonical O2-dependent HIF degradation pathway. The suppressive effects of hypercapnia on HIF-α protein stability could be mimicked by reducing intracellular pH at a constant level of partial pressure of CO2 Bafilomycin A1, a specific inhibitor of vacuolar-type H(+)-ATPase that blocks lysosomal degradation, prevented the hypercapnic suppression of HIF-α protein. Based on these results, we hypothesize that hypercapnia counter-regulates activation of the HIF pathway by reducing intracellular pH and promoting lysosomal degradation of HIF-α subunits. Therefore, hypercapnia may play a key role in the pathophysiology of diseases where HIF is implicated.


Assuntos
Dióxido de Carbono/sangue , Hipercapnia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/fisiopatologia , Oxigênio/metabolismo , Animais , Western Blotting , Células Cultivadas , Feminino , Células HCT116 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real
17.
PLoS Biol ; 14(1): e1002347, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26752685

RESUMO

The asparagine hydroxylase, factor inhibiting HIF (FIH), confers oxygen-dependence upon the hypoxia-inducible factor (HIF), a master regulator of the cellular adaptive response to hypoxia. Studies investigating whether asparagine hydroxylation is a general regulatory oxygen-dependent modification have identified multiple non-HIF targets for FIH. However, the functional consequences of this outside of the HIF pathway remain unclear. Here, we demonstrate that the deubiquitinase ovarian tumor domain containing ubiquitin aldehyde binding protein 1 (OTUB1) is a substrate for hydroxylation by FIH on N22. Mutation of N22 leads to a profound change in the interaction of OTUB1 with proteins important in cellular metabolism. Furthermore, in cultured cells, overexpression of N22A mutant OTUB1 impairs cellular metabolic processes when compared to wild type. Based on these data, we hypothesize that OTUB1 is a target for functional hydroxylation by FIH. Additionally, we propose that our results provide new insight into the regulation of cellular energy metabolism during hypoxic stress and the potential for targeting hydroxylases for therapeutic benefit.


Assuntos
Cisteína Endopeptidases/metabolismo , Oxigenases de Função Mista/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Cisteína Endopeptidases/genética , Enzimas Desubiquitinantes , Metabolismo Energético , Células HEK293 , Humanos , Hidroxilação , Mutagênese Sítio-Dirigida , Estabilidade Proteica
18.
Sci Rep ; 5: 17851, 2015 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-26647819

RESUMO

The hypoxia-inducible factor (HIF) is a key regulator of the cellular response to hypoxia which promotes oxygen delivery and metabolic adaptation to oxygen deprivation. However, the degree and duration of HIF-1α expression in hypoxia must be carefully balanced within cells in order to avoid unwanted side effects associated with excessive activity. The expression of HIF-1α mRNA is suppressed in prolonged hypoxia, suggesting that the control of HIF1A gene transcription is tightly regulated by negative feedback mechanisms. Little is known about the resolution of the HIF-1α protein response and the suppression of HIF-1α mRNA in prolonged hypoxia. Here, we demonstrate that the Repressor Element 1-Silencing Transcription factor (REST) binds to the HIF-1α promoter in a hypoxia-dependent manner. Knockdown of REST using RNAi increases the expression of HIF-1α mRNA, protein and transcriptional activity. Furthermore REST knockdown increases glucose consumption and lactate production in a HIF-1α- (but not HIF-2α-) dependent manner. Finally, REST promotes the resolution of HIF-1α protein expression in prolonged hypoxia. In conclusion, we hypothesize that REST represses transcription of HIF-1α in prolonged hypoxia, thus contributing to the resolution of the HIF-1α response.


Assuntos
Regulação da Expressão Gênica , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , Proteínas Repressoras/metabolismo , Sequência de Bases , Sítios de Ligação , Biologia Computacional , Glucose/metabolismo , Glicólise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Ácido Láctico/biossíntese , Dados de Sequência Molecular , Oxigênio/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência
19.
Environ Sci Pollut Res Int ; 22(22): 17386-96, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25869438

RESUMO

Urban effluents are rich in nutrients, organic matter, pharmaceuticals and personal care products (PPCPs), pesticides, hydrocarbons, surfactants, and others. Previous studies have shown that oysters Crassostrea gigas accumulate significant levels of linear alkylbenzenes (LABs) in sanitary sewage contaminated sites, but there is little information about its toxicological effects in marine bivalves. The aim of this study was to analyze the transcription of genes in two tissues of C. gigas exposed for 12, 24, and 36 h to LABs or sanitary sewage. Likewise, the activity of antioxidant and biotransformation enzymes was measured in oysters exposed for 36 h in all groups. Oysters exposed to LABs and oysters exposed to sanitary sewage showed different patterns of transcriptional responses. LAB-exposed oysters showed lower level of biological responses than the oysters exposed to sanitary sewage. Despite the ability of the oyster C. gigas to accumulate LABs (28-fold), the data indicate that these contaminants are not the cause for the transcriptional responses observed in oysters exposed to sanitary sewage. Possibly, the biological changes observed in the sanitary sewage-exposed oysters are associated with the presence of other contaminants, which might have caused synergistic, additive, or antagonistic effects. The results show that FABP-like and GST-ω-like messenger RNAs (mRNAs) have a rapid response in tissues of oyster C. gigas exposed to sanitary sewage, suggesting a possible protective response and a role in maintaining homeostasis of these organisms.


Assuntos
Derivados de Benzeno/toxicidade , Crassostrea/efeitos dos fármacos , Esgotos/química , Poluentes Químicos da Água/toxicidade , Animais , Monitoramento Ambiental
20.
Cell Mol Life Sci ; 72(12): 2431-43, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25697863

RESUMO

Cyclooxygenase 2 (COX2), a key regulatory enzyme of the prostaglandin/eicosanoid pathway, is an important target for anti-inflammatory therapy. It is highly induced by pro-inflammatory cytokines in a Nuclear factor kappa B (NFκB)-dependent manner. However, the mechanisms determining the amplitude and dynamics of this important pro-inflammatory event are poorly understood. Furthermore, there is significant difference between human and mouse COX2 expression in response to the inflammatory stimulus tumor necrosis factor alpha (TNFα). Here, we report the presence of a molecular logic AND gate composed of two NFκB response elements (NREs) which controls the expression of human COX2 in a switch-like manner. Combining quantitative kinetic modeling and thermostatistical analysis followed by experimental validation in iterative cycles, we show that the human COX2 expression machinery regulated by NFκB displays features of a logic AND gate. We propose that this provides a digital, noise-filtering mechanism for a tighter control of expression in response to TNFα, such that a threshold level of NFκB activation is required before the promoter becomes active and initiates transcription. This NFκB-regulated AND gate is absent in the mouse COX2 promoter, most likely contributing to its differential graded response in promoter activity and protein expression to TNFα. Our data suggest that the NFκB-regulated AND gate acts as a novel mechanism for controlling the expression of human COX2 to TNFα, and its absence in the mouse COX2 provides the foundation for further studies on understanding species-specific differential gene regulation.


Assuntos
Ciclo-Oxigenase 2/genética , Regulação da Expressão Gênica , Modelos Teóricos , NF-kappa B/metabolismo , Regiões Promotoras Genéticas/genética , Elementos de Resposta/genética , Animais , Western Blotting , Células Cultivadas , Imunoprecipitação da Cromatina , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Células HEK293 , Células HT29 , Humanos , Camundongos , NF-kappa B/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
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