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1.
Br J Nutr ; : 1-10, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077406

RESUMO

The study of polyphenols' effects on health has been gaining attention lately. In addition to reacting with important enzymes, altering the cell metabolism, these substances can present either positive or negative metabolic alterations depending on their consumption levels. Naringenin, a citrus flavonoid, already presents diverse metabolic effects. The objective of this work was to evaluate the effect of maternal naringenin supplementation during pregnancy on the tricarboxylic acid cycle activity in offspring's cerebellum. Adult female Wistar rats were divided into two groups: (1) vehicle (1 ml/kg by oral administration (p.o.)) or (2) naringenin (50 mg/kg p.o.). The offspring were euthanised at 7th day of life, and the cerebellum was dissected to analyse citrate synthase, isocitrate dehydrogenase (IDH), α-ketoglutarate dehydrogenase (α-KGDH) and malate dehydrogenase (MDH) activities. Molecular docking used SwissDock web server and FORECASTER Suite, and the proposed binding pose image was created on UCSF Chimera. Data were analysed by Student's t test. Naringenin supplementation during pregnancy significantly inhibited IDH, α-KGDH and MDH activities in offspring's cerebellum. A similar reduction was observed in vitro, using purified α-KGDH and MDH, subjected to pre-incubation with naringenin. Docking simulations demonstrated that naringenin possibly interacts with dehydrogenases in the substrate and cofactor binding sites, inhibiting their function. Naringenin administration during pregnancy may affect cerebellar development and must be evaluated with caution by pregnant women and their physicians.

2.
Glia ; 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32003513

RESUMO

Astrogliosis comprises a variety of changes in astrocytes that occur in a context-specific manner, triggered by temporally diverse signaling events that vary with the nature and severity of brain insults. However, most mechanisms underlying astrogliosis were described using animals, which fail to reproduce some aspects of human astroglial signaling. Here, we report an in vitro model to study astrogliosis using human-induced pluripotent stem cells (iPSC)-derived astrocytes which replicate temporally intertwined aspects of reactive astrocytes in vivo. We analyzed the time course of astrogliosis by measuring nuclear translocation of NF-kB, production of cytokines, changes in morphology and function of iPSC-derived astrocytes exposed to TNF-α. We observed NF-kB p65 subunit nuclear translocation and increased gene expression of IL-1ß, IL-6, and TNF-α in the first hours following TNF-α stimulation. After 24 hr, conditioned media from iPSC-derived astrocytes exposed to TNF-α exhibited increased secretion of inflammation-related cytokines. After 5 days, TNF-α-stimulated cells presented a typical phenotype of astrogliosis such as increased immunolabeling of Vimentin and GFAP and nuclei with elongated shape and shrinkage. Moreover, ~50% decrease in aspartate uptake was observed during the time course of astrogliosis with no evident cell damage, suggesting astroglial dysfunction. Together, our results indicate that human iPSC-derived astrocytes reproduce canonical events associated with astrogliosis in a time dependent fashion. The approach described here may contribute to a better understanding of mechanisms governing human astrogliosis with potential applicability as a platform to uncover novel biomarkers and drug targets to prevent or mitigate astrogliosis associated with human brain disorders.

3.
J Cell Mol Med ; 24(1): 88-97, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31654493

RESUMO

We aim to characterize the kinetics of early and late microglial phenotypes after systemic inflammation in an animal model of severe sepsis and the effects of minocycline on these phenotypes. Rats were subjected to CLP, and some animals were treated with minocycline (10 ug/kg) by i.c.v. administration. Animals were killed 24 hours, 5, 10 and 30 days after sepsis induction, and serum and hippocampus were collected for subsequent analyses. Real-time PCR was performed for M1 and M2 markers. TNF-α, IL-1ß, IL-6, IL-10, CCL-22 and nitrite/nitrate levels were measured. Immunofluorescence for IBA-1, CD11b and arginase was also performed. We demonstrated that early after sepsis, there was a preponderant up-regulation of M1 markers, and this was not switched to M2 phenotype markers later on. We found that up-regulation of both M1 and M2 markers co-existed up to 30 days after sepsis induction. In addition, minocycline induced a down-regulation, predominantly, of M1 markers. Our results suggest early activation of M1 microglia that is followed by an overlap of both M1 and M2 phenotypes and that the beneficial effects of minocycline on sepsis-associated brain dysfunction may be related to its effects predominantly on the M1 phenotype.

4.
Chemosphere ; 244: 125400, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31809933

RESUMO

Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups. Control group received mineral oil; The simple exposure (SE) group was exposed only in adulthood (0.5 mg/kg/day); and double exposure (DE) was pre-exposed to MeHg 0.5 mg/kg/day during pregnancy and breastfeeding (±40 days) and re-exposed to MeHg for 45 days from day 100. After, we evaluated possible abnormalities. Behavioral and biochemical parameters in liver and occipital cortex (CO), markers of liver injury, redox and AKT/GSK3ß/mTOR signaling pathway. Our results showed that both groups treated with MeHg presented significant alterations, such as decreased locomotion and exploration and impaired visuospatial perception. The rats exposed to MeHg showed severe liver damage and increased hepatic glycogen concentration. The MeHg groups showed significant impairment in redox balance and oxidative damage to liver macromolecules and CO. MeHg upregulated the AKT/GSK3ß/mTOR pathway and the phosphorylated form of the Tau protein. In addition, we found a reduction in NeuN and GFAP immunocontent. These results represent the first approach to the hepatotoxic and neural effects of foetal and adult MeHg exposure.

5.
Neurochem Int ; 134: 104647, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31877349

RESUMO

BACKGROUND: Neonatal sepsis is defined as a systemic inflammatory response caused by a suspected or proven infection, occurring in the first month of life, and remains one of the main causes of morbidity and mortality in newborn and preterm infants. Frequently, survivors of neonatal sepsis have serious long-term cognitive impairment and adverse neurologic outcomes. There is currently no specific drug treatment for sepsis. Indole-3-guanylhydrazone hydrochloride (LQM01) is an aminoguanidine derivative that has been described as an anti-inflammatory, antihypertensive and antioxidant with potential applicability in inflammatory diseases. METHODS: We used a LPS-challenged neonatal sepsis rodent model to investigate the effect of LQM01 on cognitive impairment and anxiety-like behavior in sepsis mice survivors, and examined the possible molecular mechanisms involved. RESULTS: It was found that LQM01 exposure during the neonatal period reduces anxiety-like behavior and cognitive impairment caused by lipopolysaccharides (LPS) in adult life. Additionally, treatment with LQM01 decreased pro-inflammatory cytokine levels and reduced NFκB, COX-2, MAPK and microglia activation in hippocampus of neonatal mice. Furthermore, LQM01 was also able to prevent oxidative damage in hippocampus of neonatal mice and preserve brain barrier integrity. CONCLUSIONS: LQM01 attenuated inflammatory reactions in an LPS-challenged neonatal sepsis mice model through the MAPK and NFκB signaling pathways and microglia activation suppression. All these findings are associated with mitigated cognitive impairment in 70 days-old LQM01 treated-mice. GENERAL SIGNIFICANCE: We revealed the effect of LQM01 as an anti-septic agent, and the role of crucial molecular pathways in mitigating the potential damage caused by neonatal sepsis.

6.
Mol Cell Biochem ; 462(1-2): 11-23, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31446616

RESUMO

BRCA-1 is a nuclear protein involved in DNA repair, transcriptional regulation, and cell cycle control. Its involvement in other cellular processes has been described. Here, we aimed to investigate the role of BRCA-1 in macrophages M(LPS), M(IL-4), and tumor cell-induced differentiation. We used siRNAs to knockdown BRCA-1 in RAW 264.7 macrophages exposed to LPS, IL-4, and C6 glioma cells conditioned medium (CMC6), and evaluated macrophage differentiation markers and functional phagocytic activity as well as DNA damage and cell survival in the presence and absence of BRCA-1. LPS and CMC6, but not by IL-4, increased DNA damage in macrophages, and this effect was more pronounced in BRCA-1-depleted cells, including M(IL-4). BRCA-1 depletion impaired expression of pro-inflammatory cytokines, TNF-α and IL-6, and reduced the phagocytic activity of macrophages in response to LPS. In CMC6-induced differentiation, BRCA-1 knockdown inhibited TNF-α and IL-6 expression which was accompanied by upregulation of the anti-inflammatory markers IL-10 and TGF-ß and reduced phagocytosis. In contrast, M(IL-4) phenotype was not affected by BRCA-1 status. Molecular docking predicted that the conserved BRCA-1 domain BRCT can interact with the p65 subunit of NF-κB. Immunofluorescence assays showed that BRCA-1 and p65 co-localize in the nucleus of LPS-treated macrophages and reporter gene assay showed that depletion of BRCA-1 decreased LPS and CMC6-induced NF-κB transactivation. IL-4 had no effect upon NF-κB. Taken together, our findings suggest a role of BRCA-1 in macrophage differentiation and phagocytosis induced by LPS and tumor cells secretoma, but not IL-4, in a mechanism associated with inhibition of NF-κB.


Assuntos
Proteína BRCA1/metabolismo , Polaridade Celular , Inflamação/patologia , Ativação de Macrófagos , Macrófagos/metabolismo , Macrófagos/patologia , NF-kappa B/metabolismo , Animais , Biomarcadores/metabolismo , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Polaridade Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Dano ao DNA , Inflamação/metabolismo , Lipopolissacarídeos , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Metaloproteinases da Matriz/metabolismo , Camundongos , Fagocitose/efeitos dos fármacos , Células RAW 264.7 , RNA Interferente Pequeno/metabolismo , Ratos
7.
J Cell Biochem ; 120(12): 19730-19737, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31297896

RESUMO

Tyrosine hydroxylase (TH) is the key enzyme that controls the rate of synthesis of the catecholamines. SH-SY5Y cells with stable transfections of either human tyrosine hydroxylase isoform 1 (hTH1) or human tyrosine hydroxylase isoform 4 (hTH4) were used to determined the subcellular distribution of TH protein and phosphorylated TH, under basal conditions and after muscarine stimulation. Muscarine was previously shown to increase the phosphorylation of only serine 19 and serine 40 in hTH1 cells. Under basal conditions, the hTH1 and hTH4 proteins, their serine 19 phosphorylated forms and hTH1 phosphorylated at serine 40 were all similarly distributed; with ~80% in the cytosolic fraction, ~20% in the membrane fraction, and less than 1%, or not detectable, in the nuclear fraction. However, hTH4 phosphorylated at serine 71 had a significantly different distribution with ~65% cytosolic and ~35% membrane associated. Muscarine stimulation led to hTH1 being redistributed from the cytosol and nuclear fractions to the membrane fraction and hTH4 being redistributed from the cytosol to the nuclear fraction. These muscarine stimulated redistributions were not due to TH phosphorylation at serine 19, serine 40, or serine 71 and were most likely due to TH binding to proteins whose phosphorylation was increased by muscarine. This is the first study to show a difference in subcellular distribution between two human TH isoforms under basal and stimulated conditions.

8.
Cell Signal ; 62: 109356, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31288066

RESUMO

Recent studies have investigated the use of retinoic acid (RA) molecule in combined chemotherapies to cancer cells as an attempt to increase treatment efficiency and circumvent cell resistance. Positive results were obtained in clinical trials from lung cancer patients treated with RA and cisplatin. Meanwhile, the signalling process that results from the interaction of both molecules remains unclear. One of the pathways that RA is able to modulate is the activity of NRF2 transcription factor, which is highly associated with tumour progression and resistance. Therefore, the aim of this work was to investigate molecular mechanism of RA and cisplatin co-treatment in A549 cells, focusing in NRF2 pathway. To this end, we investigated NRF2 and NRF2-target genes expression, cellular redox status, cisplatin-induced apoptosis, autophagy and DNA repair through homologous recombination. RA demonstrated to have an inhibitory effect over NRF2 activation, which regulates the expression of thiol antioxidants enzymes. Moreover, RA increased reactive species production associated with increased oxidation of thiol groups within the cells. The expression of proteins associated with DNA repair through homologous recombination was also suppressed by RA pre-treatment. All combined, these effects appear to create a more sensitive cellular environment to cisplatin treatment, increasing apoptosis frequency. Interestingly, autophagy was also increased by combination therapy, suggesting a resistance mechanism by A549 cells. In conclusion, these results provided new information about molecular mechanisms of RA and cisplatin treatment contributing to chemotherapy optimization.

9.
Int Immunopharmacol ; 75: 105743, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31357087

RESUMO

Macrophages are immune system cells that respond to various pathogenic insults. The recognition of antigens is performed through receptors such as TLR4 and RAGE, which recognize pathogen-associated patterns (PAMPs), including lipopolysaccharide (LPS) from Gram-negative bacteria. Carvacrol (CAR) is a phenolic compound found in some essential oils commonly used in folk medicine for treatment of inflammation-related diseases. Previous works observed strong antioxidant actions and some anti-inflammatory effects by CAR in in vivo and in vitro assays. However, the potential pharmacological application of CAR remains limited as details on its mechanisms of action are still missing. Here we investigated the molecular pathways by which CAR acts on LPS-mediated pro-inflammatory activation of RAW 264.7 macrophages. CAR 100 µM protected cells against loss of cell viability induced by LPS (1 µg/mL). Pre-incubation with CAR prevented LPS-induced ERK1/2 phosphorylation, but it had no effect on p38 and JNK activation. The effect of LPS on NF-kB (p65) translocation from cytoplasm to nucleus was inhibited by CAR, as well as NF-kB transcriptional activation. Moreover, LPS-elicited release of TNF-α and IL-1ß were inhibited by CAR, as well as activation of phagocytic activity. Such effects may be related to the antioxidant effect of CAR, as the LPS-induced increase in reactive species (RS) production (assessed by DCFH oxidation) and nitric oxide (NO) production (assessed by nitrite quantification) were inhibited by CAR. Altogether, these results demonstrate that CAR exerts relevant anti-inflammatory actions through a cellular mechanism involving ERK1/2 and NF-kB inhibition and possibly related to the antioxidant properties of this phenolic compound.

10.
Brain Behav Immun ; 80: 879-888, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31176000

RESUMO

Sepsis is characterized by a severe and disseminated inflammation. In the central nervous system, sepsis promotes synaptic dysfunction and permanent cognitive impairment. Besides sepsis-induced neuronal dysfunction, glial cell response has been gaining considerable attention with microglial activation as a key player. By contrast, astrocytes' role during acute sepsis is still underexplored. Astrocytes are specialized immunocompetent cells involved in brain surveillance. In this context, the potential communication between the peripheral immune system and astrocytes during acute sepsis still remains unclear. We hypothesized that peripheral blood mononuclear cell (PBMC) mediators are able to affect the brain during an episode of acute sepsis. With this in mind, we first performed a data-driven transcriptome analysis of blood from septic patients to identify common features among independent clinical studies. Our findings evidenced pronounced impairment in energy-related signaling pathways in the blood of septic patients. Since astrocytes are key for brain energy homeostasis, we decided to investigate the communication between PBMC mediators and astrocytes in a rat model of acute sepsis, induced by cecal ligation and perforation (CLP). In the CLP animals, we identified widespread in vivo brain glucose hypometabolism. Ex vivo analyses demonstrated astrocyte reactivity along with reduced glutamate uptake capacity during sepsis. Also, by exposing cultured astrocytes to mediators released by PBMCs from CLP animals, we reproduced the energetic failure observed in vivo. Finally, by pharmacologically inhibiting phosphoinositide 3-kinase (PI3K), a central metabolic pathway downregulated in the blood of septic patients and reduced in the CLP rat brain, we mimicked the PBMC mediators effect on glutamate uptake but not on glucose metabolism. These results suggest that PBMC mediators are capable of directly mediating astrocyte reactivity and contribute to the brain energetic failure observed in acute sepsis. Moreover, the evidence of PI3K participation in this process indicates a potential target for therapeutic modulation.

11.
Phytother Res ; 33(5): 1394-1403, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30868680

RESUMO

Obesity is a metabolic disorder associated with adverse health consequences that has increased worldwide at an epidemic rate. This has encouraged many people to utilize nonprescription herbal supplements for weight loss without knowledge of their safety or efficacy. However, mounting evidence has shown that some herbal supplements used for weight loss are associated with adverse effects. Guarana seed powder is a popular nonprescription dietary herb supplement marketed for weight loss, but no study has demonstrated its efficacy or safety when administered alone. Wistar rats were fed four different diets (low-fat diet and Western diet with or without guarana supplementation) for 18 weeks. Metabolic parameters, gut microbiota changes, and toxicity were then characterized. Guarana seed powder supplementation prevented weight gain, insulin resistance, and adipokine dysregulation induced by Western diet compared with the control diet. Guarana induced brown adipose tissue expansion, mitochondrial biogenesis, uncoupling protein-1 overexpression, AMPK activation, and minor changes in gut microbiota. Molecular docking suggested a direct activation of AMPK by four guarana compounds tested here. We propose that brown adipose tissue activation is one of the action mechanisms involved in guarana supplementation-induced weight loss and that direct AMPK activation may underlie this mechanism. In summary, guarana is an attractive potential therapeutic agent to treat obesity.


Assuntos
Adipocinas/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Resistência à Insulina , Paullinia/química , Animais , Dieta Hiperlipídica/efeitos adversos , Dieta Ocidental , Suplementos Nutricionais , Humanos , Masculino , Simulação de Acoplamento Molecular , Obesidade/metabolismo , Ratos , Ratos Wistar , Ganho de Peso , Perda de Peso/efeitos dos fármacos
12.
Neurochem Int ; 126: 27-35, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30849398

RESUMO

Carvacrol (CARV) presents valuable biological properties such as anti-inflammatory and antioxidant activities. However, pharmacological uses of CARV are largely limited due to disadvantages related to solubility, bioavailability, preparation and storage processes. The complexation of monoterpenes with ß-cyclodextrin (ß-CD) increases their stability, solubility and oral bioavailability. Here, the protective effect of oral treatment with CARV/ß-CD complex (25 µg/kg/day) against dopaminergic (DA) denervation induced by unilateral intranigral injection of 6-hydroxydopamine (6-OHDA - 10 µg per rat) was analyzed, in order to evaluate a putative application in the development of neuroprotective therapies for Parkinson's disease (PD). Pretreatment with CARV/ß-CD for 15 days prevented the loss of DA neurons induced by 6-OHDA in adult Wistar rats. This effect may occur through CARV anti-inflammatory and antioxidant properties, as the pretreatment with CARV/ß-CD inhibited the release of IL-1ß and TNF-α; besides, CARV prevented the increase of mitochondrial superoxide production induced by 6-OHDA in cultured SH-SY5Y cells. Importantly, hepatotoxicity or alterations in blood cell profile were not observed with oral administration of CARV/ß-CD. Therefore, this study showed a potential pharmacological application of CARV/ß-CD in PD using a non-invasive route of drug delivery, i.e., oral administration.


Assuntos
/administração & dosagem , Denervação/efeitos adversos , Neurônios Dopaminérgicos/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Oxidopamina/toxicidade , beta-Ciclodextrinas/administração & dosagem , Administração Oral , Animais , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Combinação de Medicamentos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar
13.
Biochem Pharmacol ; 163: 440-450, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30878553

RESUMO

Glioblastoma multiforme is the most aggressive type of primary brain tumor associated with few therapeutic opportunities and poor prognosis. In this study, we evaluated the efficacy of combining temozolomide (TMZ) with suberoylanilide hydroxamic acid (SAHA) - a specific histone deacetylases inhibitor - in glioma models in vitro and in vivo. In glioma cell lines, combined TMZ/SAHA promoted more cytotoxicity, G2/M arrest and apoptosis than either drugs alone. G2/M arrest was detected as soon as 24 h post drug exposure and preceded apoptosis, which occurred from 72 h treatment. TMZ and SAHA, alone or combined, also stimulated autophagy as evaluated by means of acridine orange staining and immunodetection of LC3I-II conversion and p62/SQSTM1 degradation. Time-course of autophagy accompanied G2/M arrest and preceded apoptosis, and blockage of late steps of autophagy with chloroquine (CQ) augmented SAHA/TMZ toxicity leading to apoptosis. In orthotopic gliomas in vivo, combined SAHA/TMZ showed better antitumor efficacy than either drugs alone, and adding CQ to the regimen improved antiglioma effects of SAHA and TMZ monotherapies without further benefit on combined SAHA/TMZ. In summary, the herein presented data suggest that autophagy acts as a protective response that impairs efficacy of SAHA and TMZ. Inhibiting autophagy termination with CQ may offer means to improve antitumor effects of SAHA and TMZ in gliomas and possibly other cancers.


Assuntos
Cloroquina/uso terapêutico , Temozolomida/uso terapêutico , Vorinostat/uso terapêutico , Animais , Antimaláricos/administração & dosagem , Antimaláricos/uso terapêutico , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Astrócitos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Proteína Beclina-1/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cloroquina/administração & dosagem , Quimioterapia Combinada , Técnicas de Silenciamento de Genes , Humanos , Ratos , Ratos Wistar , Temozolomida/administração & dosagem , Vorinostat/administração & dosagem
14.
Neurochem Int ; 125: 25-34, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30739037

RESUMO

Vitamin A (retinol) is involved in signaling pathways regulating gene expression and was postulated to be a major antioxidant and anti-inflammatory compound of the diet. Parkinson's disease (PD) is a progressive neurodegenerative disorder, characterized by loss of nigral dopaminergic neurons, involving oxidative stress and pro-inflammatory activation. The aim of the present study was to evaluate the neuroprotective effects of retinol oral supplementation against 6-hydroxydopamine (6-OHDA, 12 µg per rat) nigrostriatal dopaminergic denervation in Wistar rats. Animals supplemented with retinol (retinyl palmitate, 3000 IU/kg/day) during 28 days exhibited increased retinol content in liver, although circulating retinol levels (serum) were unaltered. Retinol supplementation did not protect against the loss of dopaminergic neurons (assessed through tyrosine hydroxylase immunofluorescence and Western blot). Retinol supplementation prevented the effect of 6-OHDA on Iba-1 levels but had no effect on 6-OHDA-induced GFAP increase. Moreover, GFAP levels were increased by retinol supplementation alone. Rats pre-treated with retinol did not present oxidative damage or thiol redox modifications in liver, and the circulating levels of TNF-α, IL-1ß, IL-6 and IL-10 were unaltered by retinol supplementation, demonstrating that the protocol used here did not cause systemic toxicity to animals. Our results indicate that oral retinol supplementation is not able to protect against 6-OHDA-induced dopaminergic denervation, and it may actually stimulate astrocyte reactivity without altering parameters of systemic toxicity.


Assuntos
Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Degeneração Neural/induzido quimicamente , Degeneração Neural/tratamento farmacológico , Simpatectomia Química/métodos , Vitamina A/administração & dosagem , Administração Oral , Animais , Neurônios Dopaminérgicos/metabolismo , Masculino , Degeneração Neural/metabolismo , Técnicas de Cultura de Órgãos , Ratos , Ratos Wistar , Resultado do Tratamento
15.
Mol Neurobiol ; 56(5): 3079-3089, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30094805

RESUMO

The receptor for advanced glycation endproducts (RAGE) is a transmembrane, immunoglobulin-like receptor that interacts with a broad repertoire of extracellular ligands. RAGE belongs to a family of cell adhesion molecules and is considered a key receptor in the inflammation axis and a potential contributor to the neurodegeneration. The present study aimed to investigate the content and cell localization of RAGE in the brain of Wistar rats subjected to systemic inflammation induced by a single dose of lipopolysaccharide (LPS, 5 mg/kg, i.p.). Fifteen days after LPS administration, the content of RAGE was analyzed in the prefrontal cortex (PFC), hippocampus (HIPP), cerebellum (CB), and substantia nigra (SN) were investigated. RAGE levels increased in all structures, except HIPP; however, immunohistochemistry analysis demonstrated that the cell site of RAGE expression changed from blood vessel-like structures to neuronal cells in all brain areas. Besides, the highest level of RAGE expression was found in SN. Immunofluorescence analysis in SN confirmed that RAGE expression was mainly co-localized in endothelial cells (RAGE/PECAM-1 co-staining) in untreated animals, while LPS-treated animals had RAGE expression predominantly in dopaminergic neurons (RAGE/TH co-staining). Decreased TH levels, as well as increased pro-inflammatory markers (TNF-α, IL-1ß, Iba-1, GFAP, and phosphorylated ERK1/2) in SN, occurred concomitantly to RAGE stimulation in the same site. These results suggest a role for RAGE in the establishment of a neuroinflammation-neurodegeneration axis that develops as a long-term response to systemic inflammation by LPS.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Células Endoteliais/metabolismo , Inflamação/metabolismo , Neurônios/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Animais , Biomarcadores/metabolismo , Neurônios Dopaminérgicos/metabolismo , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Masculino , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Ratos Wistar , Substância Negra/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
16.
Biochim Biophys Acta Mol Cell Res ; 1866(3): 317-328, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30529222

RESUMO

Retinoic acid (RA) promotes differentiation in multiple neurogenic cell types by promoting gene reprogramming through retinoid receptors and also by inducing cytosolic signaling events. The nuclear RXR receptors are one of the main mediators of RA cellular effects, classically by joining the direct receptors of RA, the nuclear RAR receptors, in RAR/RXR dimers which act as transcription factors. Distinct RXR genes lead to RXRα, RXRß and RXRγ subtypes, but their specific roles in neuronal differentiation remain unclear. We firstly investigated both RXRs and RARs expression profiles during RA-mediated neuronal differentiation of human neuroblastoma cell line SH-SY5Y, and found varying levels of retinoid receptors transcript and protein contents along the process. In order to understand the roles of the expression of distinct RXR subtypes to RA signal transduction, we performed siRNA-mediated silencing of RXRα and RXRß during the first stages of SH-SY5Y differentiation. Our results showed that RXRα is required for RA-induced neuronal differentiation of SH-SY5Y cells, since its silencing compromised cell cycle arrest and prevented the upregulation of neuronal markers and the adoption of neuronal morphology. Besides, silencing of RXRα affected the phosphorylation of ERK1/2. By contrast, silencing of RXRß improved neurite extension and led to increased expression of tau and synaptophysin, suggesting that RXRß may negatively regulate neuronal parameters related to neurite outgrowth and function. Our results indicate distinct functions for RXR subtypes during RA-dependent neuronal differentiation and reveal new perspectives for studying such receptors as clinical targets in therapies aiming at restoring neuronal function.


Assuntos
Neuritos/metabolismo , Receptor X Retinoide alfa/fisiologia , Receptor X Retinoide beta/fisiologia , Animais , Pontos de Checagem do Ciclo Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Neurônios Dopaminérgicos/fisiologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Neuroblastoma/genética , Neuroblastoma/metabolismo , Ratos , Receptores Citoplasmáticos e Nucleares/genética , Receptores do Ácido Retinoico/metabolismo , Receptores do Ácido Retinoico/fisiologia , Receptor X Retinoide alfa/metabolismo , Receptor X Retinoide beta/metabolismo , Receptores X Retinoide , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional , Tretinoína/metabolismo , Tretinoína/farmacologia , Células Tumorais Cultivadas
17.
Free Radic Biol Med ; 129: 286-295, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30268887

RESUMO

Obesity is a prevalent multifactorial chronic disorder characterized by metabolic dysregulation. Sustained pro-oxidative mediators trigger harmful consequences that reflect at systemic level and contribute for the establishment of a premature senescent phenotype associated with macromolecular damage (DNA, protein, and lipids). Telomeres are structures that protect chromosome ends and are associated with a six-protein complex called the shelterin complex and subject to regulation. Under pro-oxidant conditions, telomere attrition and the altered expression of the shelterin proteins are central for the establishment of many pathophysiological conditions such as obesity. Thus, considering that individuals with obesity display a systemic oxidative stress profile that may compromise the telomeres length or its regulation, the aim of this study was to investigate telomere homeostasis in patients with obesity and explore broad/systemic associations with the expression of shelterin genes and the plasma redox state. We performed a cross-sectional study in 39 patients with obesity and 27 eutrophic subjects. Telomere length (T/S ratio) and gene expression of shelterin components were performed in peripheral blood mononuclear cells by qPCR. The oxidative damage (lipid peroxidation and protein carbonylation) and non-enzymatic antioxidant system (total radical-trapping antioxidant potential/reactivity, sulfhydryl and GSH content) were evaluated in plasma. Our results demonstrate that independently of comorbidities, individuals with obesity had significantly shorter telomeres, augmented expression of negative regulators of the shelterin complex, increased lipid peroxidation and higher oxidized protein levels associated with increased non-enzymatic antioxidant defenses. Principal component analysis revealed TRF1 as a major contributor for firstly telomeres shortening. In conclusion, our study is first showing a comprehensive analysis of telomeres in the context of obesity, associated with dysregulation of the shelterin components that was partially explained by TRF1 upregulation that could not be reversed by the observed adaptive non-enzymatic antioxidant response.


Assuntos
Leucócitos Mononucleares/metabolismo , Obesidade/genética , Encurtamento do Telômero , Proteínas de Ligação a Telômeros/genética , Telômero/metabolismo , Proteína 1 de Ligação a Repetições Teloméricas/genética , Adulto , Estudos Transversais , Feminino , Regulação da Expressão Gênica , Glutationa/metabolismo , Humanos , Leucócitos Mononucleares/patologia , Peroxidação de Lipídeos , Masculino , Obesidade/metabolismo , Obesidade/patologia , Cultura Primária de Células , Análise de Componente Principal , Carbonilação Proteica , Transdução de Sinais , Telômero/ultraestrutura , Proteínas de Ligação a Telômeros/metabolismo , Proteína 1 de Ligação a Repetições Teloméricas/metabolismo
18.
Ecotoxicol Environ Saf ; 165: 44-51, 2018 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-30179764

RESUMO

Obesity is an important nutritional disorder worldwide. Its association with environmental pollution may trigger an increase in oxidative stress and inflammatory parameters. Coal is a resource used throughout the world as an important fuel source for generating electricity. The ashes released by the coal combustion cause serious problems for human health due to their high toxicity and their capacity to bioaccumulate. The aim of this work was to investigate the effects of coal dust inhalation in the organs of obese and non-obese Wistar rats. Pro-inflammatory cytokines, oxidative stress, oxidative damage, histological analysis, comet assay, and micronuclei were investigated. Both obesity and coal dust inhalation increased the pro-inflammatory cytokines IL-1ß and TNF-α and decreased HSP70 levels in serum, however, in obese animals that inhaled coal dust these changes were more pronounced. Liver histological analysis showed severe microvesicular steatosis in obese animals that inhaled coal dust. Lung histologic investigation showed abnormalities in lung structure of animals exposed to coal dust and showed severe lung distensibility in obese animals exposed to coal dust. The comet assay showed DNA damage in animals subjected to coal. In addition, there were modulations in enzymatic activities and damage to protein and lipids. Based on our results, the coal dust inhalation can potentiate the pro-inflammatory profile present in obese rats. We also observed an increase in the protein oxidative damage in obese rats that inhaled coal dust. Taken together, our results suggest that the combination of obesity and coal inhalation increased the risks of the development of diseases related to oxidative stress and inflammation.


Assuntos
Carvão Mineral/toxicidade , Dano ao DNA , Obesidade/patologia , Estresse Oxidativo , Administração por Inalação , Animais , Citocinas/sangue , Poeira , Mediadores da Inflamação/sangue , Fígado/efeitos dos fármacos , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Obesidade/sangue , Obesidade/metabolismo , Ratos , Ratos Wistar
19.
Food Res Int ; 113: 57-64, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30195546

RESUMO

Rice bran is obtained from the rice polishing process, and this by-product contains many bioactive compounds. In this study, the composition of phenolic compounds from red and black rice brans was determined by HPLC-DAD-MS. Additionally, the neuroprotective ability of these brans in SH-SY5Y cells insulted with hydrogen peroxide (H2O2) was evaluated. The phenolic constituents of rice bran were separated into hydrophilic and pellet fractions. The major phenolic compound in both samples was ferulic acid. Cyanidin 3-glucoside was the main anthocyanin in black rice bran. The hydrophilic and pellet fractions showed a protective effect (38-94%) on SH-SY5Y cells insulted by H2O2 in DCFH-DA assay. No extract showed cytotoxicity in the SRB assay. These results suggest a neuroprotective effect of red and black rice brans extracts due to their high antioxidant capacity, along with the absence of cytotoxicity. Thus, they may potentially be used as sources of bioactive compounds.


Assuntos
Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Oryza/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Sementes/química , Antocianinas/análise , Antioxidantes , Linhagem Celular Tumoral , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Cumáricos/análise , Glucosídeos/análise , Humanos , Fenóis/análise , Compostos Fitoquímicos/análise , Extratos Vegetais/química
20.
Ecotoxicol Environ Saf ; 162: 603-615, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30031321

RESUMO

Ubiquitous low-dose methylmercury (MeHg) exposure through an increased fish consumption represents a global public health problem, especially among pregnant women. A plethora of micronutrients presented in fish affects MeHg uptake/distribution, but limited data is available. Vitamin A (VitA), another fish micronutrient is used in nutritional supplementation, especially during pregnancy. However, there is no information about the health effects arising from their combined exposure. Therefore, the present study aimed to examine the effects of both MeHg and retinyl palmitate administered on pregnant and lactating rats in metabolic and redox parameters from dams and their offspring. Thirty Wistar female rats were orally supplemented with MeHg (0,5 mg/kg/day) and retinyl palmitate (7500 µg RAE/kg/day) via gavage, either individually or in combination from the gestational day 0 to weaning. For dams (150 days old) and their offspring (31 days old), glycogen accumulation (hepatic and cardiac) and retinoid contents (plasma and liver) were analyzed. Hg deposition in liver tissue was quantified. Redox parameters (liver, kidney, and heart) were evaluated for both animals. Cytogenetic damage was analyzed with micronucleus test. Our results showed no general toxic or metabolic alterations in dams and their offspring by MeHg-VitA co-administration during pregnancy and lactation. However, increased lipoperoxidation in maternal liver and a disrupted pro-oxidant response in the heart of male pups was encountered, with apparently no particular effects in the antioxidant response in female offspring. GST activity in dam kidney was altered leading to possible redox disruption of this tissue with no alterations in offspring. Finally, the genomic damage was exacerbated in both male and female pups. In conclusion, low-dose MeHg exposure and retinyl palmitate supplementation during gestation and lactation produced a potentiated pro-oxidant effect, which was tissue-specific. Although this is a pre-clinical approach, we recommend precaution for pregnant women regarding food consumption, and we encourage more epidemiological studies to assess possible modulations effects of MeHg-VitA co-administration at safe or inadvertently used doses in humans, which may be related to specific pathologies in mothers and their children.


Assuntos
Antioxidantes/farmacologia , Lactação , Compostos de Metilmercúrio/toxicidade , Vitamina A/análogos & derivados , Animais , Animais Recém-Nascidos , Catalase/metabolismo , Suplementos Nutricionais , Diterpenos , Feminino , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Compostos de Metilmercúrio/sangue , Oxirredução/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Vitamina A/sangue , Vitamina A/metabolismo , Vitamina A/farmacologia
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