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2.
iScience ; 27(2): 108894, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38318367

RESUMO

Amino acid (AA) transporters (AAT) control AA cellular fluxes across membranes, contributing to maintain cellular homeostasis. In this study, we took advantage of rainbow trout metabolic feature, which highly relies on dietary AA, to explore the cellular and physiological consequences of unbalanced diets on AAT dysregulations with a particular focus on cationic AAs (CAA), frequently underrepresented in plant-based diets. Results evidenced that 24 different CAAT are expressed in various trout tissues, part of which being subjected to AA- and CAA-dependent regulations, with y+LAT2 exchanger being prone to the strongest dysregulations. Moreover, CAA were shown to control two major AA-dependent activation pathways (namely mTOR and GCN2) but at different strength according to the CAA considered. A new feed formulation strategy has been put forward to improve specifically the CAA supplemented absorption in fish together with their growth performance. Such "precision formulation" strategy reveals high potential for nutrition practices, especially in aquaculture.

3.
Autophagy ; : 1-17, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798944

RESUMO

Chaperone-mediated autophagy (CMA) is a major pathway of lysosomal proteolysis critical for cellular homeostasis and metabolism, and whose defects have been associated with several human pathologies. While CMA has been well described in mammals, functional evidence has only recently been documented in fish, opening up new perspectives to tackle this function under a novel angle. Now we propose to explore CMA functions in the rainbow trout (RT, Oncorhynchus mykiss), a fish species recognized as a model organism of glucose intolerance and characterized by the presence of two paralogs of the CMA-limiting factor Lamp2A (lysosomal associated membrane protein 2A). To this end, we validated a fluorescent reporter (KFERQ-PA-mCherry1) previously used to track functional CMA in mammalian cells, in an RT hepatoma-derived cell line (RTH-149). We found that incubation of cells with high-glucose levels (HG, 25 mM) induced translocation of the CMA reporter to lysosomes and/or late endosomes in a KFERQ- and Lamp2A-dependent manner, as well as reduced its half-life compared to the control (5 mM), thus demonstrating increased CMA flux. Furthermore, we observed that activation of CMA upon HG exposure was mediated by generation of mitochondrial reactive oxygen species, and involving the antioxidant transcription factor Nfe2l2/Nrf2 (nfe2 like bZIP transcription factor 2). Finally, we demonstrated that CMA plays an important protective role against HG-induced stress, primarily mediated by one of the two RT Lamp2As. Together, our results provide unequivocal evidence for CMA activity existence in RT and highlight both the role and regulation of CMA during glucose-related metabolic disorders.Abbreviations: AREs: antioxidant response elements; CHC: α-cyano -4-hydroxycinnamic acid; Chr: chromosome; CMA: chaperone-mediated autophagy; CT: control; DMF: dimethyl fumarate; Emi: endosomal microautophagy; HG: high-glucose; HMOX1: heme oxygenase 1; H2O2: hydrogen peroxide; KFERQ: lysine-phenylalanine-glutamate-arginine-glutamine; LAMP1: lysosomal associated membrane protein 1; LAMP2A: lysosomal associated membrane protein 2A; MCC: Manders' correlation coefficient; Manders' correlation coefficient Mo: morpholino oligonucleotide; NAC: N-acetyl cysteine; NFE2L2/NRF2: NFE2 like bZIP transcription factor 2; PA-mCherry: photoactivable mCherry; PCC: Pearson's correlation coefficient; ROS: reactive oxygen species; RT: rainbow trout; siRNAs: small interfering RNAs; SOD: superoxide dismutase; Tsg101: tumor susceptibility 101; TTFA: 2-thenoyltrifluoroacetone; WGD: whole-genome duplication.

4.
Artigo em Inglês | MEDLINE | ID: mdl-37085140

RESUMO

Rainbow trout (Oncorhynchus mykiss) is traditionally considered as a poor user of digestible carbohydrates harbouring persistent postprandial hyperglycaemia and decreased growth performances when fed a diet containing more than 20% of digestible carbohydrates. While this glucose-intolerant phenotype is well-described in juveniles, evidence points to a particular regulation of glucose metabolism in rainbow trout broodstrocks. By detecting changes in glucose levels and triggering a specific metabolic response, the hypothalamus plays a key role in the regulation of peripheral glucose metabolism. Therefore, our objective was to assess, for the first time in fish, the short-term consequences in hypothalamus, the glucose sensing and feed intake regulation of feeding mature female and male, and neomale rainbow trout with a diet containing either no or a 33% carbohydrate. The hypothalamic glucosensing capacity was assessed through mRNA levels of glucosensing related-genes and feed intake regulation through appetite-regulating peptides. Our data indicate that a brief period of carbohydrate intake (5 meals at 8 °C) did not induce specific changes in glucosensing capacity and appetite-regulating peptides in the hypothalamus of rainbow trout broodstock. Our results did however demonstrate, for the first time in fish, the existence of sex dimorphism of glucosensing-related genes and appetite-regulating peptides.


Assuntos
Oncorhynchus mykiss , Feminino , Masculino , Animais , Oncorhynchus mykiss/fisiologia , Apetite , Caracteres Sexuais , Glucose/metabolismo , Peptídeos/metabolismo , Hipotálamo/metabolismo
5.
Brain Struct Funct ; 228(2): 475-492, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36380034

RESUMO

Although great efforts to characterize the embryonic phase of brain microvascular system development have been made, its postnatal maturation has barely been described. Here, we compared the molecular and functional properties of brain vascular cells on postnatal day (P)5 vs. P15, via a transcriptomic analysis of purified mouse cortical microvessels (MVs) and the identification of vascular-cell-type-specific or -preferentially expressed transcripts. We found that endothelial cells (EC), vascular smooth muscle cells (VSMC) and fibroblasts (FB) follow specific molecular maturation programs over this time period. Focusing on VSMCs, we showed that the arteriolar VSMC network expands and becomes contractile resulting in a greater cerebral blood flow (CBF), with heterogenous developmental trajectories within cortical regions. Samples of the human brain cortex showed the same postnatal maturation process. Thus, the postnatal phase is a critical period during which arteriolar VSMC contractility required for vessel tone and brain perfusion is acquired and mature.


Assuntos
Células Endoteliais , Músculo Liso Vascular , Humanos , Camundongos , Animais , Músculo Liso Vascular/fisiologia , Encéfalo/irrigação sanguínea , Contração Muscular
6.
PLoS One ; 17(8): e0273198, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35981051

RESUMO

The ribosomal protein uL11 is located at the basis of the ribosome P-stalk and plays a paramount role in translational efficiency. In addition, no mutant for uL11 is available suggesting that this gene is haplo-insufficient as many other Ribosomal Protein Genes (RPGs). We have previously shown that overexpression of Drosophila melanogaster uL11 enhances the transcription of many RPGs and Ribosomal Biogenesis genes (RiBis) suggesting that uL11 might globally regulate the level of translation through its transcriptional activity. Moreover, uL11 trimethylated on lysine 3 (uL11K3me3) interacts with the chromodomain of the Enhancer of Polycomb and Trithorax Corto, and both proteins co-localize with RNA Polymerase II at many sites on polytene chromosomes. These data have led to the hypothesis that the N-terminal end of uL11, and more particularly the trimethylation of lysine 3, supports the extra-ribosomal activity of uL11 in transcription. To address this question, we mutated the lysine 3 codon using a CRISPR/Cas9 strategy and obtained several lysine 3 mutants. We describe here the first mutants of D. melanogaster uL11. Unexpectedly, the uL11K3A mutant, in which the lysine 3 codon is replaced by an alanine, displays a genuine Minute phenotype known to be characteristic of RPG deletions (longer development, low fertility, high lethality, thin and short bristles) whereas the uL11K3Y mutant, in which the lysine 3 codon is replaced by a tyrosine, is unaffected. In agreement, the rate of translation decreases in uL11K3A but not in uL11K3Y. Co-immunoprecipitation experiments show that the interaction between uL11 and the Corto chromodomain is impaired by both mutations. However, Histone Association Assays indicate that the mutant proteins still bind chromatin. RNA-seq analyses from wing imaginal discs show that Corto represses RPG expression whereas very few genes are deregulated in uL11 mutants. We propose that Corto, by repressing RPG expression, ensures that all ribosomal proteins are present at the correct stoichiometry, and that uL11 fine-tunes its transcriptional regulation of RPGs.


Assuntos
Proteínas de Drosophila , Lisina , Proteínas Ribossômicas , Animais , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Lisina/genética , Lisina/metabolismo , Mutação , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Ativação Transcricional/genética
7.
Int J Mol Sci ; 23(6)2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35328356

RESUMO

The replacement of fishmeal by plant proteins in aquafeeds imposes the use of synthetic methionine (MET) sources to balance the amino acid composition of alternative diets and so to meet the metabolic needs of fish of agronomic interest such as rainbow trout (RT-Oncorhynchus mykiss). Nonetheless, debates still exist to determine if one MET source is more efficiently used than another by fish. To address this question, the use of fish cell lines appeared a convenient strategy, since it allowed to perfectly control cell growing conditions notably by fully depleting MET from the media and studying which MET source is capable to restore cell growth/proliferation and metabolism when supplemented back. Thus, results of cell proliferation assays, Western blots, RT-qPCR and liquid chromatography analyses from two RT liver-derived cell lines revealed a better absorption and metabolization of DL-MET than DL-Methionine Hydroxy Analog (MHA) with the activation of the mechanistic Target Of Rapamycin (mTOR) pathway for DL-MET and the activation of integrated stress response (ISR) pathway for MHA. Altogether, the results clearly allow to conclude that both synthetic MET sources are not biologically equivalent, suggesting similar in vivo effects in RT liver and, therefore, questioning the MHA efficiencies in other RT tissues.


Assuntos
Oncorhynchus mykiss , Ração Animal/análise , Animais , Linhagem Celular , Dieta , Hepatócitos/metabolismo , Fígado/metabolismo , Metionina/análogos & derivados , Metionina/química , Oncorhynchus mykiss/metabolismo
8.
Artigo em Inglês | MEDLINE | ID: mdl-34848371

RESUMO

Adipogenesis is a tightly regulated process, and the involvement of autophagy has been recently proposed in mammalian models. In rainbow trout, two well-defined phases describe the development of primary cultured adipocyte cells: proliferation and differentiation. Nevertheless, information on the transcriptional profile at the onset of differentiation and the potential role of autophagy in this process is scarce. In the present study, the cells showed an early and transient induction of several adipogenic transcription factors genes' expression (i.e., cebpa and cebpb) along with the morphological changes (round shape filled with small lipid droplets) typical of the onset of adipogenesis. Then, the expression of various lipid metabolism-related genes involving the synthesis (fas), uptake (fatp1 and cd36), accumulation (plin2) and mobilization (hsl) of lipids, characteristic of the mature adipocyte, increased. In parallel, several autophagy markers (i.e., atg4b, gabarapl1 and lc3b) mirrored the expression of those adipogenic-related genes, suggesting a role of autophagy during in vitro fish adipogenesis. In this regard, the incubation of preadipocytes with lysosomal inhibitors (Bafilomycin A1 or Chloroquine), described to prevent autophagy flux, delayed the process of adipogenesis (i.e., cell remodelling), thus suggesting a possible relationship between autophagy and adipocyte differentiation in trout. Moreover, the disruption of the autophagic flux altered the expression of some key adipogenic genes such as cebpa and pparg. Overall, this study contributes to improve our knowledge on the regulation of rainbow trout adipocyte differentiation, and highlights for the first time in fish the involvement of autophagy on adipogenesis, suggesting a close-fitting connection between both processes.


Assuntos
Adipogenia , Oncorhynchus mykiss , Adipócitos , Adipogenia/genética , Animais , Autofagia , Diferenciação Celular , Metabolismo dos Lipídeos , Oncorhynchus mykiss/genética
9.
J Stroke Cerebrovasc Dis ; 30(12): 106148, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34644665

RESUMO

Studies have demonstrated the beneficial effects of light- and moderate-intensity physical exercise on the nervous system of animals with cerebral ischemia. To investigate the effects of two high-intensity physical exercise protocols, standardized for resistance and strength gain, in rats trained before cerebral ischemia induced by Bilateral Common Carotid Artery Occlusion (BCCAO). Forty-eight male Wistar rats were divided into two groups: with ischemia and without ischemia (sham). Both groups were subdivided into animals that performed high-intensity exercises in the muscle strength modality (I+Ex2; Sham+Ex2; n=16); animals submitted to high-intensity exercises in the aerobic modality (I+Ex1; Sham+Ex1; n=16), and animals that did not practice physical exercises - sedentary (I+Sed; Sham+Sed, n=16). Cerebral ischemia was induced using the BCCAO model. The physical training program used before the procedure was of high intensity, in the aerobic and muscular strength modalities, and was performed using a vertical ladder, for 4 weeks, 5 days per week. In order to process and stain the brain tissue, the Nissl method was used for neuron labeling and quantification in the cortex, striatum, and hippocampus. As for the animals' body weight and the heart weight differences were found between the groups I+Ex2 and Sham+Ex2 (p<0.05). Data on neuron quantification in the cerebral cortex, dentate gyrus, and right and left striatum revealed significant differences between groups. High-intensity physical training in the strength gain modality promotes significant damage to the animal's brain when performed prior to BCCAO-induced cerebral ischemia.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , Condicionamento Físico Animal , Animais , Lesões Encefálicas/epidemiologia , Isquemia Encefálica/etiologia , Doenças das Artérias Carótidas/complicações , Masculino , Condicionamento Físico Animal/efeitos adversos , Condicionamento Físico Animal/fisiologia , Ratos , Ratos Wistar
10.
Cell Rep ; 32(11): 108141, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32937117

RESUMO

Glucose homeostasis is maintained through organ crosstalk that regulates secretion of insulin to keep blood glucose levels within a physiological range. In type 2 diabetes, this coordinated response is altered, leading to a deregulation of beta cell function and inadequate insulin secretion. Reprogramming of white adipose tissue has a central role in this deregulation, but the critical regulatory components remain unclear. Here, we demonstrate that expression of the transcriptional coregulator GPS2 in white adipose tissue is correlated with insulin secretion rate in humans. The causality of this relationship is confirmed using adipocyte-specific GPS2 knockout mice, in which inappropriate secretion of insulin promotes glucose intolerance. This phenotype is driven by adipose-tissue-secreted factors, which cause increased pancreatic islet inflammation and impaired beta cell function. Thus, our study suggests that, in mice and in humans, GPS2 controls the reprogramming of white adipocytes to influence pancreatic islet function and insulin secretion.


Assuntos
Tecido Adiposo Branco/metabolismo , Células Secretoras de Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Adipócitos Brancos/metabolismo , Tecido Adiposo/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Glucose/metabolismo , Intolerância à Glucose/metabolismo , Inflamação/metabolismo , Insulina/metabolismo , Resistência à Insulina/genética , Secreção de Insulina/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/metabolismo
11.
Cells ; 9(8)2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32707879

RESUMO

Nowadays, aquaculture provides more than 50% of fish consumed worldwide but faces new issues that challenge its sustainability. One of them relies on the replacement of fish meal (FM) in aquaculture feeds by other protein sources without deeply affecting the whole organism's homeostasis. Multiple strategies have already been tested using in vivo approaches, but they hardly managed to cope with the multifactorial problems related to the complexities of fish biology together with new feed formulations. In this context, rainbow trout (RT) is particularly concerned by these problems, since, as a carnivorous fish, dietary proteins provide the amino acids required to supply most of its energetic metabolism. Surprisingly, we noticed that in vitro approaches considering RT cell lines as models to study RT amino acid metabolism were never previously used. Therefore, we decided to investigate if, and how, three major pathways described, in other species, to be regulated by amino acid and to control cellular homeostasis were functional in a RT cell line called RTH-149-namely, the mechanistic Target Of Rapamycin (mTOR), autophagy and the general control nonderepressible 2 (GCN2) pathways. Our results not only demonstrated that these three pathways were functional in RTH-149 cells, but they also highlighted some RT specificities with respect to the time response, amino acid dependencies and the activation levels of their downstream targets. Altogether, this article demonstrated, for the first time, that RT cell lines could represent an interesting alternative of in vivo experimentations for the study of fish nutrition-related questions.


Assuntos
Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Oncorhynchus mykiss/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Aminoácidos/metabolismo , Aminoácidos/farmacologia , Animais , Aquicultura/métodos , Autofagia/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Cloroquina/farmacologia , Meios de Cultura/química , Expressão Gênica/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Neoplasias Hepáticas/patologia , Transdução de Sinais/efeitos dos fármacos
12.
Mol Biol Evol ; 37(10): 2887-2899, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32437540

RESUMO

Chaperone-mediated autophagy (CMA) is a major pathway of lysosomal proteolysis recognized as a key player of the control of numerous cellular functions, and whose defects have been associated with several human pathologies. To date, this cellular function is presumed to be restricted to mammals and birds, due to the absence of an identifiable lysosome-associated membrane protein 2A (LAMP2A), a limiting and essential protein for CMA, in nontetrapod species. However, the recent identification of expressed sequences displaying high homology with mammalian LAMP2A in several fish species challenges that view and suggests that CMA likely appeared earlier during evolution than initially thought. In the present study, we provide a comprehensive picture of the evolutionary history of the LAMP2 gene in vertebrates and demonstrate that LAMP2 indeed appeared at the root of the vertebrate lineage. Using a fibroblast cell line from medaka fish (Oryzias latipes), we further show that the splice variant lamp2a controls, upon long-term starvation, the lysosomal accumulation of a fluorescent reporter commonly used to track CMA in mammalian cells. Finally, to address the physiological role of Lamp2a in fish, we generated knockout medaka for that specific splice variant, and found that these deficient fish exhibit severe alterations in carbohydrate and fat metabolisms, in consistency with existing data in mice deficient for CMA in liver. Altogether, our data provide the first evidence for a CMA-like pathway in fish and bring new perspectives on the use of complementary genetic models, such as zebrafish or medaka, for studying CMA in an evolutionary perspective.


Assuntos
Autofagia Mediada por Chaperonas , Evolução Molecular , Proteína 2 de Membrana Associada ao Lisossomo/genética , Oryzias/genética , Animais , Metabolismo dos Carboidratos , Linhagem Celular , Éxons , Fibroblastos/fisiologia , Humanos , Metabolismo dos Lipídeos , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Camundongos , Oryzias/metabolismo
13.
R Soc Open Sci ; 7(2): 191853, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32257342

RESUMO

Astyanax mexicanus has gained importance as a laboratory model organism for evolutionary biology. However, little is known about its intermediary metabolism, and feeding regimes remain variable between laboratories holding this species. We thus aimed to evaluate the intermediary metabolism response to nutritional status and to low (NC) or high (HC) carbohydrate diets in various organs of the surface-dwelling form of the species. As expected, glycaemia increased after feeding. Fish fed the HC diet had higher glycaemia than fish fed the NC diet, but without displaying hyperglycaemia, suggesting that carbohydrates are efficiently used as an energy source. At molecular level, only fasn (Fatty Acid Synthase) transcripts increased in tissues after refeeding, suggesting an activation of lipogenesis. On the other hand, we monitored only moderate changes in glucose-related transcripts. Most changes observed were related to the nutritional status, but not to the NC versus HC diet. Such a metabolic pattern is suggestive of an omnivorous-related metabolism, and this species, at least at adult stage, may adapt to a fish meal-substituted diet with high carbohydrate content and low protein supply. Investigation to identify molecular actors explaining the efficient use of such a diet should be pursued to deepen our knowledge on this species.

14.
Physiol Genomics ; 51(9): 411-431, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31282806

RESUMO

Carnivorous rainbow trout exhibit prolonged postprandial hyperglycemia when fed a diet exceeding 20% carbohydrate content. This poor capacity to utilize carbohydrates has led to rainbow trout being classified as "glucose-intolerant" (GI). The metabolic phenotype has spurred research to identify the underlying cellular and molecular mechanisms of glucose intolerance, largely because carbohydrate-rich diets provide economic and ecological advantages over traditionally used fish meal, considered unsustainable for rainbow trout aquaculture operations. Evidence points to a contribution of hepatic intermediary carbohydrate and lipid metabolism, as well as upstream insulin signaling. Recently, microRNAs (miRNAs), small noncoding RNAs acting as negative posttranscriptional regulators affecting target mRNA stability and translation, have emerged as critical regulators of hepatic control of glucose-homeostasis in mammals, revealing that dysregulated hepatic miRNAs might play a role in organismal hyperglycemia in metabolic disease. To determine whether hepatic regulatory miRNA networks may contribute to GI in rainbow trout, we induced prolonged postprandial hyperglycemia in rainbow trout by using a carbohydrate-rich diet and profiled genome-wide hepatic miRNAs in hyperglycemic rainbow trout compared with fasted trout and trout fed a diet devoid of carbohydrates. Using small RNA next-generation sequencing and real-time RT-PCR validation, we identified differentially regulated hepatic miRNAs between these groups and used an in silico approach to predict bona fide mRNA targets and enriched pathways. Diet-induced hyperglycemia resulted in differential regulation of hepatic miRNAs compared with fasted fish. Some of the identified miRNAs, such as miRNA-27b-3p and miRNA-200a-3p, are known to be responsive to hyperglycemia in the liver of hyperglycemic glucose-tolerant fish and mammals, suggesting an evolutionary conserved regulation. Using Gene Ontology term-based enrichment analysis, we identify intermediate carbohydrate and lipid metabolism and insulin signaling as potential targets of posttranscriptional regulation by hyperglycemia-regulated miRNAs and provide correlative expression analysis of specific predicted miRNA-target pairs. This study identifies hepatic miRNAs in rainbow trout that exhibit differential postprandial expression in response to diets with different carbohydrate content and predicts posttranscriptionally regulated target mRNAs enriched for pathways involved in glucoregulation. Together, these results provide a framework for testable hypotheses of functional involvement of specific hepatic miRNAs in GI in rainbow trout.


Assuntos
Dieta da Carga de Carboidratos/efeitos adversos , Hiperglicemia/etiologia , Fígado/metabolismo , MicroRNAs/genética , Oncorhynchus mykiss/genética , Transcriptoma , Animais , Regulação da Expressão Gênica , Glucose/metabolismo , Intolerância à Glucose/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Insulina/metabolismo , Período Pós-Prandial/genética , Processamento Pós-Transcricional do RNA/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
15.
Blood ; 132(19): 2067-2077, 2018 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-30213874

RESUMO

The ephrin transmembrane receptor family of tyrosine kinases is involved in platelet function. We report the first EPHB2 variant affecting platelets in 2 siblings (P1 and P2) from a consanguineous family with recurrent bleeding and normal platelet counts. Whole-exome sequencing identified a c.2233C>T variant (missense p.R745C) of the EPHB2 gene. P1 and P2 were homozygous for this variant, while their asymptomatic parents were heterozygous. The p.R745C variant within the tyrosine kinase domain was associated with defects in platelet aggregation, αIIbß3 activation, and granule secretion induced by G-protein-coupled receptor (GPCR) agonists and convulxin, as well as in thrombus formation on collagen under flow. In contrast, clot retraction, flow-dependent platelet adhesion, and spreading on fibrinogen were only mildly affected, indicating limited effects on αIIbß3 outside-in signaling. Most importantly, Lyn, Syk, and FcRγ phosphorylation, the initial steps in glycoprotein VI (GPVI) platelet signaling were drastically impaired in the absence of platelet-platelet contact, indicating a positive role for EPHB2 in GPVI activation. Likewise platelet activation by PAR4-AP showed defective Src activation, as opposed to normal protein kinase C activity and Ca2+ mobilization. Overexpression of wild-type and R745C EPHB2 variant in RBL-2H3 (rat basophilic leukemia) cells stably expressing human GPVI confirmed that EPHB2 R745C mutation impaired EPHB2 autophosphorylation but had no effect on ephrin ligand-induced EPHB2 clustering, suggesting it did not interfere with EPHB2-ephrin-mediated cell-to-cell contact. In conclusion, this novel inherited platelet disorder affecting EPHB2 demonstrates this tyrosine kinase receptor plays an important role in platelet function through crosstalk with GPVI and GPCR signaling.


Assuntos
Plaquetas/patologia , Mutação de Sentido Incorreto , Ativação Plaquetária , Receptor EphB2/genética , Adolescente , Plaquetas/metabolismo , Plaquetas/ultraestrutura , Criança , Feminino , Humanos , Masculino , Linhagem , Adesividade Plaquetária , Agregação Plaquetária , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptor EphB2/metabolismo , Transdução de Sinais , Adulto Jovem
16.
Fish Shellfish Immunol ; 74: 43-51, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29288811

RESUMO

The objective of the study was to characterize the response of the antioxidant defense system against dietary prooxidant conditions in rainbow trout juveniles. Fish (initial mean weight: 62 ±â€¯1 g) were fed three fishmeal and plant-derived protein-based diets supplemented with 15% fresh fish oil (CTL diet), 15% fresh fish oil from tuna by-products (BYP diet) or 15% autooxidized fish oil (OX diet) over a 12-week growth trial at 17.5 ±â€¯0.5 °C. No significant differences in growth performance were recorded between dietary groups. Muscle lipid content was reduced and n-6 PUFA levels were increased in rainbow trout fed diets BYP and OX compared to CTL. After 12 weeks of feeding, the level of lipid peroxidation products in muscle was not affected whereas the 8-isoprostane content in liver was increased in fish fed diet OX as well as plasma total and oxidized glutathione contents. The hepatic and muscle contents for α-tocopherol were decreased in fish fed BYP and OX. Hepatic antioxidant enzyme activities and mRNA levels were not affected after 12 weeks of feeding, except for catalase and glutathione peroxidase 1b2 mRNA levels that were decreased in trout fed diet OX. Fish fed diet OX and BYP displayed also reduced cytosolic Nrf2 and both cytosolic and nuclear NF-κB protein levels in liver. The present work indicates that feeding rainbow trout juveniles with fresh fish oil from by-products or moderately oxidized lipid appears not to be detrimental to the growth performance of fish. The mechanisms beyond the control of the antioxidant defense system by moderately oxidized lipid require further investigations in rainbow trout juveniles.


Assuntos
Antioxidantes/metabolismo , Óleos de Peixe/metabolismo , Oncorhynchus mykiss/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Óleos de Peixe/administração & dosagem , Estresse Oxidativo/imunologia
17.
J Exp Biol ; 220(Pt 20): 3686-3694, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28798080

RESUMO

Environmental conditions experienced during early life play an important role in the long-term metabolic status of individuals. The present study investigated whether hypoxia exposure [for 24 h: 2.5 mg O2 l-1 (20% dissolved O2)] during the embryonic stage alone (hypoxic history) or combined with a 5-day high-carbohydrate (60%) diet stimulus at first feeding (HC dietary history) can affect glucose metabolism later in life, i.e. in juvenile fish. After 19 weeks of growth, we observed a decrease in final body mass in fish with an HC dietary history. Feed efficiency was significantly affected by both hypoxic and HC dietary histories. After a short challenge test (5 days) performed with a 30% carbohydrate diet in juvenile trout, our results also showed that, in trout that experienced hypoxic history, mRNA levels of gluconeogenic genes in liver and glucose transport genes in both liver and muscle were significantly increased at the juvenile stage. Besides, mRNA levels of glycolytic genes were decreased in fish with an HC dietary history. Both hypoxic and dietary histories barely affected plasma metabolites or global epigenetic modifications in juvenile fish after the challenge test. In conclusion, our results demonstrated that an acute hypoxic stimulus during early development alone or combined with a hyperglucidic stimulus at first feeding can modify growth performance and glucose metabolism at the molecular level in juvenile trout.


Assuntos
Glucose/metabolismo , Oncorhynchus mykiss/fisiologia , Anaerobiose , Animais , Carboidratos da Dieta/administração & dosagem , Embrião não Mamífero/fisiologia , Oncorhynchus mykiss/crescimento & desenvolvimento , Oncorhynchus mykiss/metabolismo
18.
Stud Health Technol Inform ; 245: 59-63, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29295052

RESUMO

For healthcare professionals to use mobile applications we need someone who knows software development, provide them. In healthcare institutions, health professionals use clinical protocols to govern care, and sometimes these documents are computerized through mobile applications to assist them. This work aims to present a proposal of an application of flow as a way of describing clinical protocols for automatic generation of mobile applications to assist health professionals. The purpose of this research is to enable health professionals to develop applications from the description of their own clinical protocols. As a result, we developed a web system that automates clinical protocols for an Android platform, and we validated with two clinical protocols used in a Brazilian hospital. Preliminary results of the developed architecture demonstrate the feasibility of this study.


Assuntos
Protocolos Clínicos , Aplicativos Móveis , Design de Software , Automação , Brasil , Telemedicina
19.
Sci Rep ; 6: 32187, 2016 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-27561320

RESUMO

The rainbow trout, a carnivorous fish, displays a 'glucose-intolerant' phenotype revealed by persistent hyperglycaemia when fed a high carbohydrate diet (HighCHO). Epigenetics refers to heritable changes in gene activity and is closely related to environmental changes and thus to metabolism adjustments governed by nutrition. In this study we first assessed in the trout liver whether and how nutritional status affects global epigenome modifications by targeting DNA methylation and histone marks previously reported to be affected in metabolic diseases. We then examined whether dietary carbohydrates could affect the epigenetic landscape of duplicated gluconeogenic genes previously reported to display changes in mRNA levels in trout fed a high carbohydrate diet. We specifically highlighted global hypomethylation of DNA and hypoacetylation of H3K9 in trout fed a HighCHO diet, a well-described phenotype in diabetes. g6pcb2 ohnologs were also hypomethylated at specific CpG sites in these animals according to their up-regulation. Our findings demonstrated that the hepatic epigenetic landscape can be affected by both nutritional status and dietary carbohydrates in trout. The mechanism underlying the setting up of these epigenetic modifications has now to be explored in order to improve understanding of its impact on the glucose intolerant phenotype in carnivorous teleosts.


Assuntos
Carboidratos da Dieta/farmacologia , Epigênese Genética/efeitos dos fármacos , Proteínas de Peixes/biossíntese , Fígado/metabolismo , Estado Nutricional/efeitos dos fármacos , Oncorhynchus mykiss/metabolismo , Animais
20.
Autophagy ; 12(2): 343-56, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26902586

RESUMO

Monitoring autophagic flux in vivo or in organs remains limited and the ideal methods relative to the techniques possible with cell culture may not exist. Recently, a few papers have demonstrated the feasibility of measuring autophagic flux in vivo by intraperitoneal (IP) injection of pharmacological agents (chloroquine, leupeptin, vinblastine, and colchicine). However, the metabolic consequences of the administration of these drugs remain largely unknown. Here, we report that 0.8 mg/kg/day IP colchicine increased LC3-II protein levels in the liver of fasted trout, supporting the usefulness of this drug for studying autophagic flux in vivo in our model organism. This effect was accompanied by a decrease of plasma glucose concentration associated with a fall in the mRNA levels of gluconeogenesis-related genes. Concurrently, triglycerides and lipid droplets content in the liver increased. In contrast, transcript levels of ß-oxidation-related gene Cpt1a dropped significantly. Together, these results match with the reported role of autophagy in the regulation of glucose homeostasis and intracellular lipid stores, and highlight the importance of considering these effects when using colchicine as an in vivo "autophagometer."


Assuntos
Autofagia/efeitos dos fármacos , Colchicina/farmacologia , Oncorhynchus mykiss/metabolismo , Adenilato Quinase/metabolismo , Aminoácidos de Cadeia Ramificada/metabolismo , Animais , Autofagia/genética , Biomarcadores/metabolismo , Metabolismo dos Carboidratos/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Proteínas de Peixes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/ultraestrutura , Lisossomos/metabolismo , Lisossomos/ultraestrutura , Fagossomos/efeitos dos fármacos , Fagossomos/metabolismo , Fagossomos/ultraestrutura , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Vacúolos/efeitos dos fármacos , Vacúolos/metabolismo , Vacúolos/ultraestrutura
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