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1.
Thorax ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39375039

RESUMO

The mechanism of thrombocytopenia during acute pulmonary hypertension (PH) decompensation may be partly due to platelet aggregation in the lung. Platelet aggregates in explanted lung from 16 lung transplant patients during acute PH decompensation with and without thrombocytopenia were identified by immunohistochemistry. Scanning electron microscopy (SEM) was performed. 7 explant lung controls without PH and thrombocytopenia were also examined. Compared with controls, the median number of platelet aggregates was higher in patients with acute PH decompensation with thrombocytopenia (19.4 [IQR 3.4-38.3] vs 147.5 [IQR 26.5-203.2]). SEM showed capillaries filled with platelet aggregates. Our study suggests that platelets may aggregate in the lungs during acute PH decompensation.

2.
J Am Soc Nephrol ; 33(6): 1154-1171, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35523579

RESUMO

BACKGROUND: The pathophysiology of AKI during tumor lysis syndrome (TLS) is not well understood due to the paucity of data. We aimed to decipher crystal-dependent and crystal-independent mechanisms of TLS-induced AKI. METHODS: Crystalluria, plasma cytokine levels, and extracellular histones levels were measured in two cohorts of patients with TLS. We developed a model of TLS in syngeneic mice with acute myeloid leukemia, and analyzed ultrastructural changes in kidneys and endothelial permeability using intravital confocal microscopy. In parallel, we studied the endothelial toxicity of extracellular histones in vitro. RESULTS: The study provides the first evidence that previously described crystal-dependent mechanisms are insufficient to explain TLS-induced AKI. Extracellular histones that are released in huge amounts during TLS caused profound endothelial alterations in the mouse model. The mechanisms of histone-mediated damage implicates endothelial cell activation mediated by Toll-like receptor 4. Heparin inhibits extracellular histones and mitigates endothelial dysfunction during TLS. CONCLUSION: This study sheds new light on the pathophysiology of TLS-induced AKI and suggests that extracellular histones may constitute a novel target for therapeutic intervention in TLS when endothelial dysfunction occurs.


Assuntos
Injúria Renal Aguda , Síndrome de Lise Tumoral , Injúria Renal Aguda/terapia , Animais , Endotélio , Histonas , Humanos , Rim , Camundongos , Síndrome de Lise Tumoral/tratamento farmacológico , Síndrome de Lise Tumoral/etiologia
3.
Neurocrit Care ; 34(3): 814-824, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32929599

RESUMO

OBJECTIVES: Cerebral infections related to the presence of an intraparenchymal intracranial pressure transducer (ICPT) are rare. We assessed the incidence of ICPT-related infections and colonization using culture, molecular biology, and electron microscopy. METHODS: All consecutive patients in a neurosurgical intensive care unit who had an ICPT inserted between March 2017 and February 2018 were prospectively included. Presence of colonization on the ICPTs was assessed after removal using culture, scanning electron microscopy (SEM), and next-generation sequencing (NGS). RESULTS: Fifty-three ICPTs (53 patients), indwelling for a median of 4 (range 3-7) days, were studied. Median patient follow-up was 3 months. SEM, microbial culture, and NGS were performed for 91%, 79%, and 72% of ICPTs, respectively; 28 ICPTs (53%) were assessed using all three techniques. No patient developed ICPT-related infection. Microbial cultures were positive for two of the ICPTs (5%); colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was observed on 35/48 (73%) of ICPTs. A median of 10 (8-12) operational taxonomic units were identified for each ICPT, most being of environmental origin. There was no association between biofilm maturity and antimicrobial treatment or duration of ICPT insertion. Antimicrobial treatment was associated with decreased alpha and beta-diversity (p = 0.01). CONCLUSIONS: We observed no ICPT-related cerebral infections although colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was the main bacterial lifestyle on the ICPTs.


Assuntos
Bactérias , Pressão Intracraniana , Biofilmes , Humanos , Estudos Prospectivos , Transdutores
4.
Biochim Biophys Acta ; 1860(3): 557-68, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26708991

RESUMO

BACKGROUND: Hemocyanins are respiratory proteins with multiple functions. In diverse crustaceans hemocyanins can release histidine-rich antimicrobial peptides in response to microbial challenge. In penaeid shrimp, strictly antifungal peptides are released from the C-terminus of hemocyanins. METHODS: The three-dimensional structure of the antifungal peptide PvHCt from Litopenaeus vannamei was determined by NMR. Its mechanism of action against the shrimp pathogen Fusarium oxysporum was investigated using immunochemistry, fluorescence and transmission electron microscopy. RESULTS: PvHCt folded into an amphipathic α-helix in membrane-mimicking media and displayed a random conformation in aqueous environment. In contact with F. oxysporum, PvHCt bound massively to the surface of fungal hyphae without being imported into the cytoplasm. At minimal inhibitory concentrations, PvHCt made the fungal membrane permeable to SYTOX-green and fluorescent dextran beads of 4 kDa. Higher size beads could not enter the cytoplasm. Therefore, PvHCt likely creates local damages to the fungal membrane. While the fungal cell wall appeared preserved, gradual degeneration of the cytoplasm most often resulting in cell lysis was observed in fungal spores and hyphae. In the remaining fungal cells, PvHCt induced a protective response by the formation of daughter hyphae. CONCLUSION: The massive accumulation of PvHCt at the surface of fungal hyphae and subsequent insertion into the plasma membrane disrupt its integrity as a permeability barrier, leading to disruption of internal homeostasis and fungal death. GENERAL SIGNIFICANCE: The histidine-rich antimicrobial peptide PvHCt derived from shrimp hemocyanin is a strictly antifungal peptide, which adopts an amphipathic α-helical structure, and selectively binds to and permeabilizes fungal cells.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Fusarium/efeitos dos fármacos , Hemocianinas/química , Penaeidae/química , Estrutura Secundária de Proteína , Animais , Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/efeitos dos fármacos , Hemocianinas/farmacologia , Concentração de Íons de Hidrogênio , Hifas/efeitos dos fármacos , Permeabilidade , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/metabolismo , Esporos Fúngicos/ultraestrutura
5.
Environ Sci Technol ; 50(15): 8324-34, 2016 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-27409512

RESUMO

Cyanobacterial blooms often occur in freshwater lakes and constitute a potential health risk to human populations, as well as to other organisms. However, their overall and specific implications for the health of aquatic organisms that are chronically and environmentally exposed to cyanobacteria producing hepatotoxins, such as microcystins (MCs), together with other bioactive compounds have still not been clearly established and remain difficult to assess. The medaka fish was chosen as the experimental aquatic model for studying the cellular and molecular toxicological effects on the liver after chronic exposures (28 days) to environmentally relevant concentrations of pure MC-LR, complex extracts of MC producing or nonproducing cyanobacterial biomasses, and of a Microcystis aeruginosa natural bloom. Our results showed a higher susceptibility of females to the different treatments compared to males at both the cellular and the molecular levels. Although hepatocyte lysis increased with MC-containing treatments, lysis always appeared more severe in the liver of females compare to males, and the glycogen cellular reserves also appeared to decrease more in the liver of females compared to those in the males. Proteomic investigations reveal divergent responses between males and females exposed to all treatments, especially for proteins involved in metabolic and homeostasis processes. Our observations also highlighted the dysregulation of proteins involved in oogenesis in female livers. These results suggest that fish populations exposed to cyanobacteria blooms may potentially face several ecotoxicological issues.


Assuntos
Microcystis/metabolismo , Oryzias/metabolismo , Animais , Cianobactérias/metabolismo , Lagos , Microcistinas/metabolismo , Proteômica
7.
Adv Sci (Weinh) ; 11(9): e2304454, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38115757

RESUMO

Bone is created by osteoblasts that secrete osteoid after which an ordered texture emerges, followed by mineralization. Plywood geometries are a hallmark of many trabecular and cortical bones, yet the origin of this texturing in vivo has never been shown. Nevertheless, extensive in vitro work revealed how plywood textures of fibrils can emerge from acidic molecular cholesteric collagen mesophases. This study demonstrates in sheep, which is the preferred model for skeletal orthopaedic research, that the deeper non-fibrillar osteoid is organized in a liquid-crystal cholesteric geometry. This basophilic domain, rich in acidic glycosaminoglycans, exhibits low pH which presumably fosters mesoscale collagen molecule ordering in vivo. The results suggest that the collagen fibril motif of twisted plywood matures slowly through self-assembly thermodynamically driven processes as proposed by the Bouligand theory of biological analogues of liquid crystals. Understanding the steps of collagen patterning in osteoid-maturation processes may shed new light on bone pathologies that emerge from collagen physico-chemical maturation imbalances.


Assuntos
Osso e Ossos , Colágeno , Animais , Ovinos , Osteoblastos , Osso Cortical
8.
Biotechnol Bioeng ; 109(1): 284-8, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21809325

RESUMO

Targeting the development of cell-based bioreactors for the production of metal nanoparticles, the possibility to perform the sustained synthesis of colloidal gold using Klebsormidium flaccidum green algae was studied. A first strategy relying on successive growth/reduction/reseeding recycling steps demonstrated maintained biosynthesis capability of the microalgae but limitation in metal content due to toxic effects. An alternative approach consisting of progressive gold salt addition revealed to be suitable to favor cell adaptation to larger metal concentrations and supported particle release over month periods.


Assuntos
Biotecnologia/métodos , Ouro/metabolismo , Nanopartículas Metálicas , Microalgas/metabolismo , Fotossíntese , Estreptófitas/metabolismo , Reatores Biológicos , Microalgas/fisiologia , Estreptófitas/fisiologia
9.
Harmful Algae ; 117: 102285, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35944963

RESUMO

Cyanobacterial blooms can modify the dynamic of aquatic ecosystems and have harmful consequences for human activities. Moreover, cyanobacteria can produce a variety of cyanotoxins, including microcystins, but little is known about the role of environmental factors on the prevalence of microcystin producers in the cyanobacterial bloom dynamics. This study aimed to better understand the success of Planktothrix in various environments by unveiling the variety of strategies governing cell responses to sudden changes in light intensity and temperature. The cellular responses (photosynthesis, photoprotection, heat shock response and metabolites synthesis) of four Planktothrix strains to high-light or high-temperature were studied, focusing on how distinct ecotypes (red- or green-pigmented) and microcystin production capability affect cyanobacteria's ability to cope with such abiotic stimuli. Our results showed that high-light and high-temperature impact different cellular processes and that Planktothrix responses are heterogeneous, specific to each strain and thus, to genotype. The ability of cyanobacteria to cope with sudden increase in light intensity and temperature was not related to red- or green-pigmented ecotype or microcystin production capability. According to our results, microcystin producers do not cope better to high-light or high-temperature and microcystin content does not increase in response to such stresses.


Assuntos
Cianobactérias , Planktothrix , Cianobactérias/fisiologia , Ecossistema , Genótipo , Humanos , Temperatura
10.
Nat Commun ; 13(1): 1496, 2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35314701

RESUMO

The presence of phosphate from different origins (inorganic, bioorganic) is found more and more in calcium carbonate-based biominerals. Phosphate is often described as being responsible for the stabilization of the transient amorphous calcium carbonate phase. In order to specify the composition of the mineral phase deposited at the onset of carbonated shell formation, the present study investigates, down to the nanoscale, the growing shell from the European abalone Haliotis tuberculata, using a combination of solid state nuclear magnetic resonance, scanning transmission electron microscope and spatially-resolved electron energy loss spectroscopy techniques. We show the co-occurrence of inorganic phosphate with calcium and carbonate throughout the early stages of abalone shell formation. One possible hypothesis is that this first-formed mixed mineral phase represents the vestige of a shared ancestral mineral precursor that appeared early during Evolution. In addition, our findings strengthen the idea that the final crystalline phase (calcium carbonate or phosphate) depends strongly on the nature of the mineral-associated proteins in vivo.


Assuntos
Carbonato de Cálcio , Gastrópodes , Animais , Carbonato de Cálcio/química , Fosfatos de Cálcio/química , Carbonatos , Gastrópodes/genética , Minerais/química , Fosfatos
11.
J Nanosci Nanotechnol ; 11(3): 1852-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21449320

RESUMO

The potential ecotoxicity of nanosized cadmium sulfide (CdS), synthesized by the polyol process, was investigated using common Anabaena flos-aquae cyanobacteria and Euglena gracilis euglenoid microalgae. The photosynthetic activities of these microorganisms, after addition of free Cd2+ ions and CdS nanoparticles, varied with the presence of tri-n-octylphosphine oxide (TOPO) used to protect surface particle to avoid toxicity and also to control particle size and shape during the synthesis. The nanoparticle concentration was varied from 10(-3) to 5 x 10(-4) M. It was observed that the cadmium concentration, the addition of TOPO protective agent and the particle dissolution process in the culture medium play an important role during the ecotoxicological tests. Viability tests were followed by PAM fluorimetry. Cd2+ ions were very toxic for Anabaena flos aquae. The same behavior was observed after contact with CdS and CdS-TOPO nanoparticles. However, for Euglena gracilis, the photosynthetic activity was stable for more than 1 month in the presence of Cd2+ ions. Moreover, it was observed that the toxicity varies with the concentration of CdS and CdS-TOPO nanoparticles, both kind of nanoparticles are toxic for this microorganism. Transmission electron microscopy (TEM) analyses of microorganisms ultrathin sections showed that polysaccharides produced by Anabaena flos-aquae, after contact with CdS and CdS-TOPO nanoparticles, protect the microalgae against particle internalization. Only some particles were observed inside the cells. Moreover, the nanoparticle internalization was observed after contact with all nanoparticles in the presence of Euglena gracilis by endocytosis. All nanoparticles are inside vesicles formed by the cells.


Assuntos
Compostos de Cádmio/toxicidade , Cianobactérias/efeitos dos fármacos , Cianobactérias/fisiologia , Euglena gracilis/efeitos dos fármacos , Euglena gracilis/fisiologia , Nanopartículas/toxicidade , Fotossíntese/efeitos dos fármacos , Sulfetos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Ecotoxicologia , Poluentes Ambientais/toxicidade , Fotossíntese/fisiologia
12.
Langmuir ; 26(9): 6522-8, 2010 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-20196582

RESUMO

The potential ecotoxicity of nanosized zinc oxide (ZnO), synthesized by the polyol process, was investigated using common Anabaena flos-aquae cyanobacteria and Euglena gracilis euglenoid microalgae. The photosynthetic activities of these microorganisms, after addition of ZnO nanoparticles, varied with the presence of protective agents such as tri-n-octylphosphine oxide (TOPO) and polyoxyethylene stearyl ether (Brij-76) used to control particle size and shape during the synthesis. In the case of Anabaena flos-aquae , the photosynthetic activity, after addition of ZnO, ZnO-TOPO, and ZnO-Brij-76, decreased progressively due to stress induced by the presence of the nanoparticles in the culture medium. After contact with ZnO-TOPO nanoparticles, this decrease was followed by cell death. On the other hand, after 10 days, a progressive increase of the photosynthetic activity was observed after contact with ZnO and ZnO-Brij-76 nanoparticles. In the case of Euglena gracilis , cell death was observed after contact with all nanoparticles. Transmission electron microscopy (TEM) analyses of ultrathin sections of microorganisms showed that polysaccharides produced by Anabaena flos-aquae avoid particle internalization after contact with ZnO and ZnO-Brij-76 nanoparticles. On the other hand, nanoparticle internalization was observed after contact with all nanoparticles in the presence of Euglena gracilis and also with ZnO-TOPO nanoparticles after contact with Anabaena flos-aquae .

13.
J Nat Prod ; 73(7): 1277-82, 2010 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-20590100

RESUMO

Chemical investigation of the Mediterranean calcareous sponge Clathrina clathrus led to the isolation of large amounts of a new 2-aminoimidazole alkaloid, named clathridimine (1), along with the known clathridine (2) and its zinc complex (3). The structure of the new metabolite was assigned by detailed spectroscopic analysis. Clathridimine (1) displayed selective anti-Escherichia coli and anti-Candida albicans activities. Clathridine (2) showed only anti-Candida albicans activity, and its zinc complex (3) exhibited selective anti-Staphylococcus aureus activity. The isolation of analogues of 2-amino-imidazole derivatives from several Leucetta species from various sites in the Pacific Ocean and the Red Sea raises the question of their biosynthetic origin. Microscopic studies revealed abundant extracellular bacteria located in the mesohyl of the sponge, with two predominant morphotypes including spiral bacteria and long, narrow bacilli. Chemical analysis with HPLC/UV/ELSD profiles of sponge cells separated from bacteria by differential centrifugation and trypsinization of the sponge cell surface revealed that clathridine (2) was localized in the sponge cells.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Imidazóis/isolamento & purificação , Imidazóis/farmacologia , Poríferos/química , Alcaloides/química , Animais , Antibacterianos/química , Antifúngicos/química , Candida albicans/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Imidazóis/química , Oceano Índico , Testes de Sensibilidade Microbiana , Oceano Pacífico , Staphylococcus aureus/efeitos dos fármacos
14.
Biochim Biophys Acta Bioenerg ; 1861(4): 148037, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31228405

RESUMO

Photosynthetic organisms need to sense and respond to fluctuating environmental conditions, to perform efficient photosynthesis and avoid the formation of harmful reactive oxygen species. Cyanobacteria have developed a photoprotective mechanism that decreases the energy arriving at the reaction centers by increasing thermal energy dissipation at the level of the phycobilisome, the extramembranal light-harvesting antenna. This mechanism is triggered by the photoactive orange carotenoid protein (OCP). In this study, we characterized OCP and the related photoprotective mechanism in non-stressed and light-stressed cells of three different strains of Planktothrix that can form impressive blooms. In addition to changing lake ecosystemic functions and biodiversity, Planktothrix blooms can have adverse effects on human and animal health as they produce toxins (e.g., microcystins). Three Planktothrix strains were selected: two green strains, PCC 10110 (microcystin producer) and PCC 7805 (non-microcystin producer), and one red strain, PCC 7821. The green strains colonize shallow lakes with higher light intensities while red strains proliferate in deep lakes. Our study allowed us to conclude that there is a correlation between the ecological niche in which these strains proliferate and the rates of induction and recovery of OCP-related photoprotection. However, differences in the resistance to prolonged high-light stress were correlated to a better replacement of damaged D1 protein and not to differences in OCP photoprotection. Finally, microcystins do not seem to be involved in photoprotection as was previously suggested.


Assuntos
Proteínas de Bactérias/metabolismo , Cianobactérias/fisiologia , Cianobactérias/efeitos da radiação , Luz , Estresse Fisiológico/efeitos da radiação , Proteínas de Bactérias/genética , Proteínas de Bactérias/ultraestrutura , Cianobactérias/genética , Cianobactérias/ultraestrutura , Regulação Bacteriana da Expressão Gênica/efeitos da radiação , Complexo de Proteína do Fotossistema II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
15.
Toxicon ; 159: 14-21, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30629997

RESUMO

Among the diverse toxic components produced by cyanobacteria, microcystins (MCs) are one of the most toxic and notorious cyanotoxin groups. Besides their potent hepatotoxicity, MCs have been revealed to induce potential reproductive toxicity in various animal studies. However, little is still known regarding the distribution of MCs in the reproductive organ, which could directly affect reproductive cells. In order to respond to this question, an acute study was conducted in adult medaka fish (model animal) gavaged with 10 µg.g-1 body weight of pure MC-LR. The histological and immunohistochemical examinations reveal an intense distribution of MC-LR within hepatocytes along with a severe liver lesion in the toxin-treated female and male fish. Besides being accumulated in the hepatocytes, MC-LR was also found in the connective tissue of the ovary and the testis, as well as in oocytes and degenerative spermatocyte-like structures but not spermatocytes. Both liver and gonad play important roles in the reproductive process of oviparous vertebrates. This observation constitutes the first observation of the presence of MC-LR in reproductive cells (female, oocytes) of a vertebrate model with in vivo study. Our results, which provide intracellular localization of MC-LR in the gonad, advance our understanding of the potential reproductive toxicity of MC-LR in fish.


Assuntos
Gônadas/química , Fígado/química , Microcistinas/análise , Oryzias/metabolismo , Animais , Exposição Ambiental , Feminino , Imuno-Histoquímica , Masculino , Microcistinas/toxicidade , Oócitos/química , Oócitos/efeitos dos fármacos , Reprodução/efeitos dos fármacos
16.
Front Microbiol ; 10: 791, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31057509

RESUMO

Cyanobacteria are photosynthetic prokaryotes capable of synthesizing a large variety of secondary metabolites that exhibit significant bioactivity or toxicity. Microcystis constitutes one of the most common cyanobacterial genera, forming the intensive blooms that nowadays arise in freshwater ecosystems worldwide. Species in this genus can produce numerous cyanotoxins (i.e., toxic cyanobacterial metabolites), which can be harmful to human health and aquatic organisms. To better understand variations in cyanotoxin production between clones of Microcystis species, we investigated the diversity of 24 strains isolated from the same blooms or from different populations in various geographical areas. Strains were compared by genotyping with 16S-ITS fragment sequencing and metabolite chemotyping using LC ESI-qTOF mass spectrometry. While genotyping can help to discriminate among different species, the global metabolome analysis revealed clearly discriminating molecular profiles among strains. These profiles could be clustered primarily according to their global metabolite content, then according to their genotype, and finally according to their sampling location. A global molecular network of all metabolites produced by Microcystis species highlights the production of a wide set of chemically diverse metabolites, including a few microcystins, many aeruginosins, microginins, cyanopeptolins, and anabaenopeptins, together with a large set of unknown molecules. These components, which constitute the molecular biodiversity of Microcystis species, still need to be investigated in terms of their structure and potential bioactivites (e.g., toxicity).

17.
Sci Rep ; 9(1): 19696, 2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31873127

RESUMO

Energy imbalance due to excess of calories is considered to be a major player in the current worldwide obesity pandemic and could be accompanied by systemic and central inflammation and mitochondrial dysfunctions. This hypothesis was tested by comparing the wild-derived diet-induced obesity- (DIO-) resistant mouse strain WSB/EiJ to the obesity-prone C57BL/6J strain. We analysed circulating and hypothalamic markers of inflammatory status and hypothalamic mitochondrial activity in both strains exposed to high-fat diet (HFD). We further analysed the regulations of hypothalamic genes involved in inflammation and mitochondrial pathways by high throughput microfluidic qPCR on RNA extracted from laser micro-dissected arcuate (ARC) and paraventricular (PVN) hypothalamic nuclei. HFD induced increased body weight gain, circulating levels of leptin, cholesterol, HDL and LDL in C57BL/6J whereas WSB/EiJ mice displayed a lower inflammatory status, both peripherally (lower levels of circulating cytokines) and centrally (less activated microglia in the hypothalamus) as well as more reactive mitochondria in the hypothalamus. The gene expression data analysis allowed identifying strain-specific hypothalamic metabolic pathways involved in the respective responses to HFD. Our results point to the involvement of hypothalamic inflammatory and mitochondrial pathways as key factors in the control of energy homeostasis and the resistance to DIO.


Assuntos
Inflamação/metabolismo , Mitocôndrias/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Animais , Citocinas/sangue , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Metabolismo Energético , Hipotálamo/metabolismo , Hipotálamo/patologia , Inflamação/genética , Mediadores da Inflamação/metabolismo , Leptina/sangue , Metabolismo dos Lipídeos , Masculino , Redes e Vias Metabólicas , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/patologia , Dinâmica Mitocondrial , Obesidade/genética , Núcleo Hipotalâmico Paraventricular/metabolismo , Núcleo Hipotalâmico Paraventricular/patologia , Especificidade da Espécie , Transcriptoma
18.
Neurosci Lett ; 402(1-2): 121-5, 2006 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-16714082

RESUMO

The olfactory input to the brain is carried out by olfactory nerve axons that terminate in the olfactory bulb glomeruli and make synapses onto dendrites of glutamatergic projection neurons, mitral and tufted cells, and GABAergic interneurons, periglomerular cells. The dendrites are reciprocally connected through asymmetric synapses of mitral/tufted cells with periglomerular cells and symmetric synapses of the opposite direction. Transmission at the first synapse in the olfactory pathway is regulated presynaptically, and this regulation is mediated, in part, by metabotropic GABAB receptors that, when activated, inhibit transmitter release from the olfactory nerve. Functional GABAB receptors are heterodimers composed of the GABAB1 and GABAB2 subunits. Studies using double immunofluorescence have shown colocalization of both subunits in the glomerular neuropil, and ultrastructural studies have localized GABAB1 to extrasynaptic, synaptic, and perisynaptic sites on the plasma membrane of olfactory nerve terminals. We studied the subcellular localization of GABAB2 in the mouse olfactory glomeruli using a subunit-specific antibody and preembedding immunogold labeling. Immunoreactivity for GABAB2 was associated with symmetric dendrodendritic synapses of periglomerular cells with mitral/tufted cells and was localized to the extrasynaptic plasma membrane of presynaptic dendrites, and extrasynaptic, synaptic, and perisynaptic sites on the plasma membrane of postsynaptic dendrites. The results suggest that postsynaptic, and perhaps presynaptic, GABAB receptors may be expressed at GABAergic synapses between dendrites of periglomerular interneurons and projection neurons. Immunolabeling was observed at junctions of the olfactory nerve with mitral/tufted cell dendrites, providing ultrastructural evidence for the expression of the GABAB2 subunit at the primary olfactory synapse.


Assuntos
Bulbo Olfatório/citologia , Neurônios Receptores Olfatórios/metabolismo , Receptores de GABA-B/metabolismo , Sinapses/metabolismo , Animais , Imuno-Histoquímica/métodos , Camundongos , Microscopia Imunoeletrônica/métodos , Neurônios Receptores Olfatórios/ultraestrutura , Subunidades Proteicas/genética , Receptores de GABA-B/genética , Sinapses/ultraestrutura
19.
Environ Pollut ; 219: 119-131, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27814527

RESUMO

Cyanobacterial blooms threaten human health as well as the population of other living organisms in the aquatic environment, particularly due to the production of natural toxic components, the cyanotoxin. So far, the most studied cyanotoxins are microcystins (MCs). In this study, the hepatic alterations at histological, proteome and transcriptome levels were evaluated in female and male medaka fish chronically exposed to 1 and 5 µg L-1 microcystin-LR (MC-LR) and to the extract of MC-producing Microcystis aeruginosa PCC 7820 (5 µg L-1 of equivalent MC-LR) by balneation for 28 days, aiming at enhancing our understanding of the potential reproductive toxicity of cyanotoxins in aquatic vertebrate models. Indeed, both MC and Microcystis extract adversely affect reproductive parameters including fecundity and egg hatchability. The liver of toxin treated female fish present glycogen storage loss and cellular damages. The quantitative proteomics analysis revealed that the quantities of 225 hepatic proteins are dysregulated. In particular, a notable decrease in protein quantities of vitellogenin and choriogenin was observed, which could explain the decrease in reproductive output. Liver transcriptome analysis through Illumina RNA-seq reveals that over 100-400 genes are differentially expressed under 5 µg L-1 MC-LR and Microcystis extract treatments, respectively. Ingenuity pathway analysis of the omic data attests that various metabolic pathways, such as energy production, protein biosynthesis and lipid metabolism, are disturbed by both MC-LR and the Microcystis extract, which could provoke the observed reproductive impairment. The transcriptomics analysis also constitutes the first report of the impairment of circadian rhythm-related gene induced by MCs. This study contributes to a better understanding of the potential consequences of chronic exposure of fish to environmental concentrations of cyanotoxins, suggesting that Microcystis extract could impact a wider range of biological pathways, compared with pure MC-LR, and even 1 µg L-1 MC-LR potentially induces a health risk for aquatic organisms.


Assuntos
Toxinas Bacterianas/toxicidade , Doença Hepática Induzida por Substâncias e Drogas , Doenças dos Peixes/induzido quimicamente , Fígado/efeitos dos fármacos , Microcistinas/toxicidade , Microcystis/química , Oryzias/fisiologia , Reprodução/efeitos dos fármacos , Animais , Toxinas Bacterianas/administração & dosagem , Extratos Celulares/administração & dosagem , Extratos Celulares/farmacologia , Ritmo Circadiano/efeitos dos fármacos , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Regulação para Baixo/efeitos dos fármacos , Feminino , Glicogênio/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Microcistinas/administração & dosagem , Oviparidade/efeitos dos fármacos , Oviparidade/genética , Biossíntese de Proteínas/efeitos dos fármacos , Proteoma/efeitos dos fármacos , Proteoma/metabolismo , Transcriptoma/efeitos dos fármacos
20.
Sci Rep ; 6: 32459, 2016 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-27561897

RESUMO

Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues.


Assuntos
Fígado/metabolismo , Oryzias/genética , Proteômica , Caracteres Sexuais , Animais , Feminino , Fígado/crescimento & desenvolvimento , Masculino , Oócitos/crescimento & desenvolvimento , Oócitos/metabolismo , Oryzias/crescimento & desenvolvimento , Oryzias/fisiologia , Biossíntese de Proteínas
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