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1.
Toxicol Pathol ; 46(3): 348-358, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29683090

RESUMEN

Aging is a multifactorial process associated with functional deficits, and the brain is more prone to developing chronic degenerative diseases such as Parkinson's disease. Several groups have tried to correlate the age-related ultrastructural alterations to the neurodegeneration process using in vivo pharmacological models, but due to the limitations of the animal models, particularly in aged animals, the results are difficult to interpret. In this work, we investigated neurodegeneration induced by rotenone, as a pharmacological model of Parkinson's disease, in both young and aged Wistar rats. We assessed animal mobility, tyrosine hydroxylase staining in the substantia nigra pars compacta (SNpc), and TdT-mediated dUTP-biotin nick end labeling-positive nuclei and reactive oxygen species production in the striatum. Interestingly, the mobility impairment, dopaminergic neuron loss, and elevated number of apoptotic nuclei in the striatum of aged control rats were similar to young rotenone-treated animals. Moreover, we observed many ultrastructural alterations, such as swollen mitochondria in the striatum, and massive lipofuscin deposits in the SNpc of the aged rotenone-treated animals. We conclude that the rotenone model can be employed to explore age-related alterations in the ontogeny that can increase vulnerability in the striatum and SNpc, which may contribute to Parkinson's disease pathogenesis.


Asunto(s)
Envejecimiento/patología , Cuerpo Estriado/patología , Trastornos Parkinsonianos/patología , Sustancia Negra/patología , Animales , Ratas , Ratas Wistar , Rotenona/toxicidad , Desacopladores/toxicidad
2.
Epilepsy Behav ; 88: 301-307, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30342389

RESUMEN

The imbalance between antioxidant system and reactive oxygen species (ROS) generation is related to epileptogenesis, neuronal death, and seizure frequency. Treatment with vitamin E has been associated with neuroprotection and control of seizures. In most experimental studies, vitamin E treatment has short duration. Therefore, the aim of this study was to verify the role of long-term treatment with vitamin E in rats submitted to the pilocarpine model of epilepsy. Rats were divided into two main groups: control (Ctr) and pilocarpine (Pilo). Each one was subdivided according to treatment: vehicle (Ctr V and Pilo V) or vitamin E at dosages of 6 IU/kg/day (Ctr E6 and Pilo E6) or 60 IU/kg/day (Ctr E60 and Pilo E60). Treatment lasted 120 days from status epilepticus (SE). There were no statistical differences concerning treatment in the Ctr group for all variables, so the data were grouped. Carbonyl content in the hippocampus of Pilo V and Pilo E6 was higher compared with that of the Ctr group (8 ±â€¯1.5, 7.1 ±â€¯1, and 3.1 ±â€¯0.3 nmol carbonyl/mg protein, respectively for Pilo V, Pilo E6, and Ctr; p < 0.05). Carbonyl content was restored to control values in Pilo E60 rats (4.2 ±â€¯1.1 and 3.1 ±â€¯0.3 nmol carbonyl/mg protein, respectively for Pilo E60 and Ctr; p > 0.05). The volume of the hippocampal formation (6.5 ±â€¯0.3, 6.6 ±â€¯0.4, 6.3 ±â€¯0.3, and 7.4 ±â€¯0.2, respectively for Pilo V, Pilo E6, Pilo E60, and Ctr) and subfields CA1 (1.6 ±â€¯0.1, 1.4 ±â€¯0.2, 1.5 ±â€¯0.1, and 2 ±â€¯0.05, respectively for Pilo V, Pilo E6, Pilo E60, and Ctr) and CA3 (1.7 ±â€¯0.1, 1.5 ±â€¯0.2, 1.4 ±â€¯0.1, and 2 ±â€¯0.1, respectively for Pilo V, Pilo E6, Pilo E60, and Ctr) was reduced in the Pilo group regardless of treatment. Parvalbumin immunostaining was increased in the hilus of the Pilo E60 group compared with that in the Ctr group (26 ±â€¯2 and 39.6 ±â€¯8.3 neurons, respectively for Ctr and Pilo E60). No difference was found in seizure frequency and Neo-Timm staining. Therefore, long-term treatment with 60 IU/kg/day of vitamin E prevented oxidative damage in the hippocampus and increased hilar parvalbumin expression in rats with epilepsy without a reduction in seizure frequency.


Asunto(s)
Antioxidantes/farmacología , Epilepsia/tratamiento farmacológico , Estrés Oxidativo/efectos de los fármacos , Pilocarpina/metabolismo , Convulsiones/tratamiento farmacológico , Vitamina E/farmacología , Análisis de Varianza , Animales , Biomarcadores/metabolismo , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Masculino , Parvalbúminas/metabolismo , Ratas , Ratas Wistar
3.
Infect Immun ; 84(4): 1112-1122, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26831466

RESUMEN

The expression of flagella correlates with different aspects of bacterial pathogenicity, ranging from adherence to host cells to activation of inflammatory responses by the innate immune system. In the present study, we investigated the role of flagella in the adherence of an atypical enteropathogenic Escherichia coli (aEPEC) strain (serotype O51:H40) to human enterocytes. Accordingly, isogenic mutants deficient in flagellin (FliC), the flagellar structural subunit; the flagellar cap protein (FliD); or the MotAB proteins, involved in the control of flagellar motion, were generated and tested for binding to differentiated Caco-2 cells. Binding of the aEPEC strain to enterocytes was significantly impaired in strains with the fliCa nd fliD genes deleted, both of which could not form flagella on the bacterial surface. A nonmotile but flagellated MotAB mutant also showed impaired adhesion to Caco-2 cells. In accordance with these observations, adhesion of a EPEC strain 1711-4 to Caco-2 cells was drastically reduced after the treatment of Caco-2 cells with purified FliD. In addition, incubation of a EPEC bacteria with specific anti-FliD serum impaired binding to Caco-2 cells. Finally, incubation of Caco-2 cells with purified FliD, followed by immunolabeling, showed that the protein was specifically bound to the microvillus tips of differentiated Caco-2 cells. The a EPEC FliD or anti-FliD serum also reduced the adherence of prototype typical enteropathogenic, enterohemorrhagic, and enterotoxigenic E. coli strains to Caco-2 cells. In conclusion, our findings further strengthened the role of flagella in the adherence of a EPEC to human enterocytes and disclosed the relevant structural and functional involvement of FliD in the adhesion process.


Asunto(s)
Adhesión Bacteriana/fisiología , Proteínas Bacterianas/metabolismo , Enterocitos/microbiología , Escherichia coli Enteropatógena/fisiología , Microvellosidades/fisiología , Animales , Anticuerpos , Proteínas Bacterianas/genética , Células CACO-2 , Enterocitos/fisiología , Escherichia coli Enteropatógena/genética , Humanos , Inmunohistoquímica , Ratones , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Mutación , Conejos , Proteínas Recombinantes
4.
Nutr Neurosci ; 18(6): 265-74, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24754536

RESUMEN

Choline - now recognized as an essential nutrient - is the most common polar group found in the outer leaflet of the plasma membrane bilayer. Brain ischemia-reperfusion causes lipid peroxidation triggering multiple cell death pathways involving necrosis and apoptosis. Membrane breakdown is, therefore, a major pathophysiologic event in brain ischemia. The ability to achieve membrane repair is a critical step for survival of ischemic neurons following reperfusion injury. The availability of choline is a rate-limiting factor in phospholipid synthesis and, therefore, may be important for timely membrane repair and cell survival. This work aimed at verifying the effects of 7-day oral administration with different doses of choline on survival of CA1 hippocampal neurons following transient global forebrain ischemia in rats. The administration of 400 mg/kg/day divided into two daily doses for 7 consecutive days significantly improved CA1 pyramidal cell survival, indicating that the local availability of this essential nutrient may limit postischemic neuronal survival.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Colina/administración & dosificación , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/administración & dosificación , Administración Oral , Animales , Apoptosis/efectos de los fármacos , Región CA1 Hipocampal/citología , Región CA1 Hipocampal/efectos de los fármacos , Región CA1 Hipocampal/metabolismo , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Peroxidación de Lípido/efectos de los fármacos , Masculino , Neuronas/citología , Ratas , Ratas Wistar
5.
Biol Chem ; 394(7): 901-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23585179

RESUMEN

A role for the kinin B1 receptor in energy-homeostatic processes was implicated in previous studies; notably, the studies where kinin B1 receptor knockout mice (B1-/-) were shown to have impaired adiposity, impaired leptin and insulin production, lower feed efficiency, protection from liver steatosis and diet-induced obesity when fed a high fat diet (HFD). In particular, in a model where the B1 receptor is expressed exclusively in the adipose tissue, it rescues the plasma insulin concentration and the weight gain seen in wild type mice. Taking into consideration that leptin participates in the formation of hypothalamic nuclei, which modulate energy expenditure, and feeding behavior, we hypothesized that these brain regions could also be altered in B1-/- mice. We observed for the first time a difference in the gene expression pattern of cocaine and amphetamine related transcript (CART) in the (lateral hypothalamic area (LHA) resulting from the deletion of the kinin B1 receptor gene. The correlation between CART expression in the LHA and the thwarting of diet-induced obesity corroborates independent correlations between CART and obesity. Furthermore, it seems to indicate that the mechanism underlying the 'lean' phenotype of B1-/- mice does not stem solely from changes in peripheral tissues but may also receive contributions from changes in the hypothalamic machinery involved in energy homeostasis processes.


Asunto(s)
Área Hipotalámica Lateral/metabolismo , Cininas/deficiencia , Proteínas del Tejido Nervioso/biosíntesis , Obesidad/genética , Obesidad/metabolismo , Animales , Peso Corporal/fisiología , Ingestión de Energía/fisiología , Inmunohistoquímica , Hibridación in Situ , Cininas/genética , Cininas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas del Tejido Nervioso/metabolismo , Neuropéptido Y/metabolismo , ARN Mensajero/química , ARN Mensajero/genética
6.
Eukaryot Cell ; 10(3): 343-51, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21216942

RESUMEN

Exosome-like vesicles containing virulence factors, enzymes, and antigens have recently been characterized in fungal pathogens, such as Cryptococcus neoformans and Histoplasma capsulatum. Here, we describe extracellular vesicles carrying highly immunogenic α-linked galactopyranosyl (α-Gal) epitopes in Paracoccidioides brasiliensis. P. brasiliensis is a dimorphic fungus that causes human paracoccidioidomycosis (PCM). For vesicle preparations, cell-free supernatant fluids from yeast cells cultivated in Ham's defined medium-glucose were concentrated in an Amicon ultrafiltration system and ultracentrifuged at 100,000 × g. P. brasiliensis antigens were present in preparations from phylogenetically distinct isolates Pb18 and Pb3, as observed in immunoblots revealed with sera from PCM patients. In an enzyme-linked immunosorbent assay (ELISA), vesicle components containing α-Gal epitopes reacted strongly with anti-α-Gal antibodies isolated from both Chagas' disease and PCM patients, with Marasmius oreades agglutinin (MOA) (a lectin that recognizes terminal α-Gal), but only faintly with natural anti-α-Gal. Reactivity was inhibited after treatment with α-galactosidase. Vesicle preparations analyzed by electron microscopy showed vesicular structures of 20 to 200 nm that were labeled both on the surface and in the lumen with MOA. In P. brasiliensis cells, components carrying α-Gal epitopes were found distributed on the cell wall, following a punctuated confocal pattern, and inside large intracellular vacuoles. Lipid-free vesicle fractions reacted with anti-α-Gal in ELISA only when not digested with α-galactosidase, while reactivity with glycoproteins was reduced after ß-elimination, which is indicative of partial O-linked chain localization. Our findings open new areas to explore in terms of host-parasite relationships in PCM and the role played in vivo by vesicle components and α-galactosyl epitopes.


Asunto(s)
Exocitosis , Espacio Extracelular/metabolismo , Paracoccidioides/metabolismo , Paracoccidioidomicosis/microbiología , Vesículas Transportadoras/metabolismo , Trisacáridos/metabolismo , Anticuerpos Antifúngicos/inmunología , Transporte Biológico , Espacio Extracelular/inmunología , Interacciones Huésped-Parásitos , Humanos , Paracoccidioides/inmunología , Paracoccidioides/patogenicidad , Paracoccidioidomicosis/inmunología , Trisacáridos/inmunología
7.
Neurobiol Dis ; 41(1): 169-76, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20850530

RESUMEN

It is well known that the uncoupling between local cerebral glucose utilization (LCGU) and local cerebral blood flow (LCBF), i.e. decrease in LCBF rates with high LCGU, is frequently associated with seizure-induced neuronal damage. This study was performed to assess if the neuroprotective effect of the adenosinergic A(1) receptor agonist R-N-phenylisopropyladenosine (R-Pia) injected prior to pilocarpine is able to reduce the uncoupling between LCGU and LCBF during status epilepticus (SE). Four groups of rats were studied: Saline, Pilo, R-Pia+Saline and R-Pia+Pilo. For LCGU and LCBF studies, rats were subjected to autoradiography using [(14)C]-2-deoxyglucose and [(14)C]-iodoantypirine, respectively. Radioligands were injected 4 h after SE onset. Neuronal loss was evaluated by Fluorojade-B (FJB) at two time points after SE onset (24 h and 7 days). The results showed a significant increase in LCGU in almost all brain regions studied in the Pilo and R-Pia+Pilo groups compared to controls. However, in R-Pia pretreated rats, the uncoupling between LCGU and LCBF was moderated in a limited number of structures as substantia nigra pars reticulata and hippocampal formation rather in favor of hyperperfusion. Significant increases in LCBF were observed in the entorhinal cortex, thalamic nuclei, mammillary body, red nucleus, zona incerta, pontine nucleus and visual cortex. The neuroprotective effect of R-Pia assessed by FJB showed a lower density of degenerating cells in the hippocampal formation, piriform cortex and basolateral amygdala. In conclusion our data shows that the neuroprotective effect of R-Pia was accompanied by a compensatory metabolic input in brain areas involved with seizures generation.


Asunto(s)
Agonistas del Receptor de Adenosina A1/farmacología , Adenosina/análogos & derivados , Circulación Cerebrovascular/efectos de los fármacos , Glucosa/metabolismo , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Estado Epiléptico/tratamiento farmacológico , Estado Epiléptico/patología , Adenosina/farmacología , Animales , Circulación Cerebrovascular/fisiología , Masculino , Neuronas/efectos de los fármacos , Neuronas/patología , Ratas , Ratas Wistar , Estado Epiléptico/metabolismo
8.
Neurochem Int ; 118: 105-114, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29864448

RESUMEN

Dystrophin deficiency caused by mutations of the related gene leads to muscle wasting in Duchenne muscular dystrophy (DMD). Some patients with DMD also present with intellectual disability and various degrees of neurological disorders, which have been related to a decreased number of postsynaptic gamma-aminobutyric acid type A receptors (GABAARs) in the hippocampus (HPC) and cerebellum (CBL). The aim of this study was to examine the relevance of dystrophin in the presynaptic GABAergic function in brain regions in which this protein is normally abundant. [3H]-GABA release, induced by nicotinic receptor (nAChR) activation or K+ depolarization, and [3H]-GABA uptake were determined using synaptosomes extracted from the cortex (CTX), HPC, and CBL of littermate control and mdx mice. Superfusion of the synaptosomes with nicotine or high K+ solutions led to a concentration-dependent and Ca2+-dependent [3H]-GABA release in control and mdx synaptosomes. [3H]-GABA release induced by 10 µM nicotine in mdx CBL synaptosomes was 47% less than that in control mice. K+-induced [3H]-GABA release did not differ between control and mdx synaptosomes. α7-containing and ß2-containing nAChRs were involved in nicotine-induced [3H]-GABA release in control and mdx synaptosomes. Kinetic analysis of [3H]-GABA uptake in mdx CBL synaptosomes showed a reduced (50%) half-maximal uptake time (t1/2) and increased (44%) rate of [3H]-GABA uptake (Vmax) compared to controls. The apparent transporter affinity (Km) for GABA was not altered. Our findings show that dystrophin deficiency in mdx mice is associated with significant changes in the release and uptake of GABA in the CBL. These presynaptic alterations may be related to the reported decrease in postsynaptic GABAAR in the same brain region. The results indicate possible dysfunction of GABAergic synapses associated with dystrophin deficiency in the CBL, which may contribute to the cognitive and neurobehavioral disorders in mdx mice and patients with DMD.


Asunto(s)
Cerebelo/metabolismo , Distrofina/deficiencia , Distrofia Muscular de Duchenne/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Cerebelo/ultraestructura , Distrofina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos mdx , Distrofia Muscular de Duchenne/genética
9.
Sci Rep ; 7(1): 14395, 2017 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-29089558

RESUMEN

Extracellular vesicles (EVs) are key mediators of intercellular communication. Part of their biological effects can be attributed to the transfer of cargos of diverse types of RNAs, which are promising diagnostic and prognostic biomarkers. EVs found in human biofluids are a valuable source for the development of minimally invasive assays. However, the total transcriptional landscape of EVs is still largely unknown. Here we develop a new method for total transcriptome profiling of plasma-derived EVs by next generation sequencing (NGS) from limited quantities of patient-derived clinical samples, which enables the unbiased characterization of the complete RNA cargo, including both small- and long-RNAs, in a single library preparation step. This approach was applied to RNA extracted from EVs isolated by ultracentrifugation from the plasma of five healthy volunteers. Among the most abundant RNAs identified we found small RNAs such as tRNAs, miRNAs and miscellaneous RNAs, which have largely unknown functions. We also identified protein-coding and long noncoding transcripts, as well as circular RNA species that were also experimentally validated. This method enables, for the first time, the full spectrum of transcriptome data to be obtained from minute patient-derived samples, and will therefore potentially allow the identification of cell-to-cell communication mechanisms and biomarkers.


Asunto(s)
Vesículas Extracelulares/metabolismo , Perfilación de la Expresión Génica/métodos , Pruebas Hematológicas/métodos , Plasma/metabolismo , Transcriptoma , Femenino , Humanos , Biopsia Líquida , MicroARNs/metabolismo
10.
Curr Eye Res ; 42(8): 1185-1193, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28494212

RESUMEN

PURPOSE: Evaluate toxicity of acai fruit (Euterpe oleracea) dye concentrations in a rabbit model. METHODS: Rabbits were injected intravitreously with 10%, 25%, and 35% acai dye concentrations. Control eyes received balanced salt solution (BSS). Electroretinogram (ERG), fundus imaging, fluorescein angiography (FA), optical coherence tomography (OCT), and light and transmission electron microscopy (LM/TEM) were performed. RESULTS: Fundus imaging showed increased vitreous opacity with increased dye concentrations. FA and OCT showed normality with all concentrations. Comparisons between BSS and dye concentrations were analyzed using Kruskal-Wallis and Mood's median test (p < 0.05). At 24 h, ERGs showed reduced amplitudes from baseline in all eyes. Median b-wave amplitudes nonsignificantly decreased and latency increased with 10% and 25%; findings were significant (p < 0.05) for 35%. LM and TEM showed no abnormalities for 10% and 25%. With 35%, TEM showed ganglion cell edema at 24 h that resolved after 7 days. Vacuolization, multilamellar bodies, and nerve bundle damage occurred at 24 h/7 days in the inner nuclear layer. Mitochondrial cristae disruption occurred in the inner photoreceptor segment at 24 h that decreased by 7 days. CONCLUSION: Ten and twenty-five percent concentrations were safe and may improve identification of the posterior hyaloid and internal limiting membrane during chromovitrectomy in humans.


Asunto(s)
Euterpe/toxicidad , Angiografía con Fluoresceína/métodos , Extractos Vegetales/toxicidad , Retina/efectos de los fármacos , Enfermedades de la Retina/cirugía , Tomografía de Coherencia Óptica/métodos , Vitrectomía/métodos , Animales , Modelos Animales de Enfermedad , Electrorretinografía/efectos de los fármacos , Euterpe/metabolismo , Frutas/metabolismo , Frutas/toxicidad , Fondo de Ojo , Humanos , Microscopía Electrónica de Transmisión , Extractos Vegetales/farmacocinética , Conejos , Retina/metabolismo , Retina/ultraestructura , Enfermedades de la Retina/inducido químicamente , Enfermedades de la Retina/diagnóstico
11.
Front Immunol ; 8: 881, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28824619

RESUMEN

Mesenchymal stromal cells (MSCs) are multipotent cells with abilities to exert immunosuppressive response promoting tissue repair. Studies have shown that MSCs can secrete extracellular vesicles (MVs-MSCs) with similar regulatory functions to the parental cells. Furthermore, strong evidence suggesting that MVs-MSCs can modulate several immune cells (i.e., Th1, Th17, and Foxp3+ T cells). However, their precise effect on macrophages (Mϕs) remains unexplored. We investigated the immunoregulatory effect of MVs-MSCs on activated M1-Mϕs in vitro and in vivo using differentiated bone marrow Mϕs and an acute experimental model of thioglycollate-induced peritonitis, respectively. We observed that MVs-MSCs shared surface molecules with MSCs (CD44, CD105, CD90, CD73) and expressed classical microvesicle markers (Annexin V and CD9). The in vitro treatment with MVs-MSCs exerted a regulatory-like phenotype in M1-Mϕs, which showed higher CD206 level and reduced CCR7 expression. This was associated with decreased levels of inflammatory molecules (IL-1ß, IL-6, nitric oxide) and increased immunoregulatory markers (IL-10 and Arginase) in M1-Mϕs. In addition, we detected that MVs-MSCs promoted the downregulation of inflammatory miRNAs (miR-155 and miR-21), as well as, upregulated its predicted target gene SOCS3 in activated M1-Mϕs. In vivo MVs-MSCs treatment reduced the Mϕs infiltrate in the peritoneal cavity inducing a M2-like regulatory phenotype in peritoneal Mϕs (higher arginase activity and reduced expression of CD86, iNOS, IFN-γ, IL-1ß, TNF-α, IL-1α, and IL-6 molecules). This in vivo immunomodulatory effect of MVs-MSCs on M1-Mϕs was partially associated with the upregulation of CX3CR1 in F4/80+/Ly6C+/CCR2+ Mϕs subsets. In summary, our findings indicate that MVs-MSCs can modulate an internal program in activated Mϕs establishing an alternative regulatory-like phenotype.

12.
Food Res Int ; 90: 139-146, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29195866

RESUMEN

Tristearin solid lipid nanoparticles and tristearin/high oleic sunflower oil nanostructured lipid carriers were produced by solvent displacement method. All conditions allowed forming polydisperse particles within nanometric range and the presence of high oleic sunflower oil did not affect the particles mean size. Nevertheless, incorporation of ß-carotene reduced the particles polydispersity. Thermograms of solid lipid nanoparticles and nanostructured lipid carriers showed that sunflower oil generated a crystal order disturbance, since nanoparticles with less-organized lipid matrix were produced. Nanostructured lipid carriers exhibited an improvement of ß-carotene loading capacity when compared with solid lipid nanoparticles, which enhanced with the increasing of high oleic sunflower oil content. Although total ß-carotene degradation was similar for all systems, color analysis showed that the degradation of encapsulated ß-carotene was lower for high sunflower oil content. Nanostructured lipid carriers exhibited advantages over the solid lipid nanoparticles, such as enhanced drug loading capacity and prevention of drug expulsion, which makes this a versatile delivery system for food applications.

13.
Autophagy ; 12(11): 2113-2128, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27629560

RESUMEN

Prion protein modulates many cellular functions including the secretion of trophic factors by astrocytes. Some of these factors are found in exosomes, which are formed within multivesicular bodies (MVBs) and secreted into the extracellular space to modulate cell-cell communication. The mechanisms underlying exosome biogenesis were not completely deciphered. Here, we demonstrate that primary cultures of astrocytes and fibroblasts from prnp-null mice secreted lower levels of exosomes than wild-type cells. Furthermore, prnp-null astrocytes exhibited reduced MVB formation and increased autophagosome formation. The reconstitution of PRNP expression at the cell membrane restored exosome secretion in PRNP-deficient astrocytes, whereas macroautophagy/autophagy inhibition via BECN1 depletion reestablished exosome release in these cells. Moreover, the PRNP octapeptide repeat domain was necessary to promote exosome secretion and to impair the formation of the CAV1-dependent ATG12-ATG5 cytoplasmic complex that drives autophagosome formation. Accordingly, higher levels of CAV1 were found in lipid raft domains instead of in the cytoplasm in prnp-null cells. Collectively, these findings demonstrate that PRNP supports CAV1-suppressed autophagy to protect MVBs from sequestration into phagophores, thus facilitating exosome secretion.


Asunto(s)
Autofagia , Caveolina 1/metabolismo , Exosomas/metabolismo , Proteínas Priónicas/metabolismo , Animales , Astrocitos/metabolismo , Exosomas/ultraestructura , Lisosomas/metabolismo , Microdominios de Membrana/metabolismo , Ratones Endogámicos C57BL , Modelos Biológicos , Cuerpos Multivesiculares/metabolismo , Cuerpos Multivesiculares/ultraestructura , Proteínas Priónicas/química , Dominios Proteicos , Secuencias Repetitivas de Ácidos Nucleicos , Relación Estructura-Actividad
14.
Biomed Res Int ; 2014: 797508, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24877131

RESUMEN

Atypical enteropathogenic Escherichia coli (aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytes in vitro (Caco-2 cells) and in vivo (rabbit ileal loops) and to translocate the rat intestinal mucosa in vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potential in vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasion in vitro and in vivo and to bacterial translocation to extraintestinal sites.


Asunto(s)
Sistemas de Secreción Bacterianos , Enterocitos/microbiología , Escherichia coli Enteropatógena/patogenicidad , Infecciones por Escherichia coli/metabolismo , Factores de Virulencia/metabolismo , Animales , Células CACO-2 , Modelos Animales de Enfermedad , Enterocitos/metabolismo , Enterocitos/patología , Escherichia coli Enteropatógena/genética , Infecciones por Escherichia coli/genética , Infecciones por Escherichia coli/patología , Humanos , Mutación , Conejos , Ratas , Factores de Virulencia/genética
15.
Neurosci Lett ; 551: 84-8, 2013 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-23880022

RESUMEN

Recent evidence indicates the involvement of orexin in reward circuitry and drug addiction. In the present study we evaluated the role of orexin in ethanol-induced behavioral sensitization. In the first experiment, Swiss male mice received seven administrations of saline or ethanol (2.2g/kg, i.p., chronic), every other day. On the last day of treatment, half of saline-treated mice received a saline injection (saline) whereas the other half received 2.2g/kg of ethanol (i.p., acute). Behavioral sensitization was assessed by locomotor activity tests and after the last one, immunoreactivity for orexin and Fos (ORX+Fos-ir) was assessed in the lateral hypothalamic area. Chronic ethanol treatment produced behavioral sensitization and a trend for greater ORX+Fos-ir. In the second experiment, mice were treated as in Experiment 1 and type 1 orexin receptor antagonist, SB334867 (20mg/kg), was administered before the ethanol challenge successfully blocking the expression of sensitization in mice chronically treated with EtOH. These results indicate that orexin plays a role in ethanol-induced behavioral sensitization.


Asunto(s)
Etanol/farmacología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Actividad Motora/efectos de los fármacos , Neuropéptidos/metabolismo , Animales , Hipotálamo/efectos de los fármacos , Hipotálamo/metabolismo , Masculino , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Orexinas , Proteínas Proto-Oncogénicas c-fos/metabolismo
16.
Behav Brain Res ; 236(1): 221-224, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-22974552

RESUMEN

We investigated the relationship between deficits in fear memory induced by sleep deprivation and pCREB expression in the basal and central nuclei of the amygdala. Sleep deprivation reduced pCREB expression in the central nucleus compared to control or sleep recovered groups, and in the basal nucleus only compared to sleep recovered group. Moreover, 24h of sleep recovery prior to training prevented changes in both pCREB expression and performance.


Asunto(s)
Amígdala del Cerebelo/metabolismo , Condicionamiento Psicológico/fisiología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Miedo/fisiología , Privación de Sueño , Animales , Inmunohistoquímica , Masculino , Memoria/fisiología , Fosforilación , Desempeño Psicomotor/fisiología , Ratas , Ratas Wistar
17.
Dermatoendocrinol ; 5(1): 222-34, 2013 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-24494059

RESUMEN

Autoimmunity has been associated with vitamin D deficiency and resistance, with gene polymorphisms related to vitamin D metabolism frequently described in affected patients. High doses of vitamin D3 may conceivably compensate for inherited resistance to its biological effects. This study aimed to assess the efficacy and safety of prolonged high-dose vitamin D3 treatment of patients with psoriasis and vitiligo. Nine patients with psoriasis and 16 patients with vitiligo received vitamin D3 35,000 IU once daily for six months in association with a low-calcium diet (avoiding dairy products and calcium-enriched foods like oat, rice or soya "milk") and hydration (minimum 2.5 L daily). All psoriasis patients were scored according to "Psoriasis Area and Severity Index" (PASI) at baseline and after treatment. Evaluation of clinical response of vitiligo patients required a quartile grading scale. All patients presented low vitamin D status (serum 25(OH)D3 ≤ 30 ng/mL) at baseline. After treatment 25(OH)D3 levels significantly increased (from 14.9 ± 7.4 to 106.3 ± 31.9 ng/mL and from 18.4 ± 8.9 to 132.5 ± 37.0 ng/mL) and PTH levels significantly decreased (from 57.8 ± 16.7 to 28.9 ± 8.2 pg/mL and from 55.3 ± 25.0 to 25.4 ± 10.7 pg/mL) in patients with psoriasis and vitiligo respectively. PTH and 25(OH)D3 serum concentrations correlated inversely. The PASI score significantly improved in all nine patients with psoriasis. Fourteen of 16 patients with vitiligo had 25-75% repigmentation. Serum urea, creatinine and calcium (total and ionized) did not change and urinary calcium excretion increased within the normal range. High-dose vitamin D3 therapy may be effective and safe for vitiligo and psoriasis patients.

18.
Prog Neuropsychopharmacol Biol Psychiatry ; 39(1): 23-30, 2012 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-22343009

RESUMEN

Aging leads to progressive deterioration of physiological function and diminished responses to environmental stress. Organic and functional alterations are frequently observed in elderly subjects. Although chronic sleep loss is observed during senescence, little is known about the impact of insufficient sleep on cellular function in aging neurons. Disruption of neuronal calcium (Ca²âº) signaling is related to impaired neuronal function and cell death. It has been hypothesized that sleep deprivation may compromise neuronal stability and induce cell death in young neurons; however, it is necessary to evaluate the impact of aging on this process. Therefore, the aim of this study was to evaluate the effects of chronic sleep restriction (CSR) on Ca²âº signaling and cell death in the hippocampus of young and aged animals. We found that glutamate and carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) induced a greater elevation in cytosolic Ca²âº ([Ca²âº](c)) in hippocampal slices from aged rats subjected to CSR compared to age-matched controls. Interestingly, aged-matched controls showed a reduced Ca²âº response to glutamate and FCCP, relative to both CSR and control young animals. Apoptotic nuclei were observed in aged rats from both treatment groups; however, the profile of apoptotic nuclei in aged CSR rats was highly variable. Bax and Bcl-2 protein expression did not change with aging in the CSR groups. Our study indicates that aging promotes changes in Ca²âº signaling, which may also be affected by CSR. These age-dependent changes in Ca²âº signaling may increase cellular vulnerability during CSR and contribute to Ca²âº signaling dysregulation, which may ultimately induce cell death.


Asunto(s)
Envejecimiento/fisiología , Apoptosis/fisiología , Señalización del Calcio/fisiología , Hipocampo/fisiopatología , Privación de Sueño/fisiopatología , Envejecimiento/metabolismo , Animales , Apoptosis/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Carbonil Cianuro p-Trifluorometoxifenil Hidrazona/farmacología , Ácido Glutámico/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Ratas , Ratas Wistar , Privación de Sueño/metabolismo , Proteína X Asociada a bcl-2/biosíntesis
19.
PLoS One ; 7(9): e44092, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22970165

RESUMEN

This study evaluated the effects of bone marrow-derived mesenchymal stem cells (BMSCs) or their conditioned medium (CM) on the repair and prevention of Acute Kidney Injury (AKI) induced by gentamicin (G). Animals received daily injections of G up to 20 days. On the 10(th) day, injections of BMSCs, CM, CM+trypsin, CM+RNase or exosome-like microvesicles extracted from the CM were administered. In the prevention groups, the animals received the BMSCs 24 h before or on the 5(th) day of G treatment. Creatinine (Cr), urea (U), FENa and cytokines were quantified. The kidneys were evaluated using hematoxylin/eosin staining and immunohystochemistry. The levels of Cr, U and FENa increased during all the periods of G treatment. The BMSC transplantation, its CM or exosome injections inhibited the increase in Cr, U, FENa, necrosis, apoptosis and also increased cell proliferation. The pro-inflammatory cytokines decreased while the anti-inflammatory cytokines increased compared to G. When the CM or its exosomes were incubated with RNase (but not trypsin), these effects were blunted. The Y chromosome was not observed in the 24-h prevention group, but it persisted in the kidney for all of the periods analyzed, suggesting that the injury is necessary for the docking and maintenance of BMSCs in the kidney. In conclusion, the BMSCs and CM minimized the G-induced renal damage through paracrine effects, most likely through the RNA carried by the exosome-like microvesicles. The use of the CM from BMSCs can be a potential therapeutic tool for this type of nephrotoxicity, allowing for the avoidance of cell transplantations.


Asunto(s)
Lesión Renal Aguda/prevención & control , Lesión Renal Aguda/terapia , Células de la Médula Ósea/citología , Gentamicinas/efectos adversos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Cicatrización de Heridas , Lesión Renal Aguda/sangre , Lesión Renal Aguda/inducido químicamente , Animales , Medios de Cultivo Condicionados/farmacología , Citocinas/sangre , Exosomas/metabolismo , Exosomas/ultraestructura , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Comunicación Paracrina/efectos de los fármacos , Ratas , Ratas Wistar , Cicatrización de Heridas/efectos de los fármacos
20.
ISRN Endocrinol ; 2011: 480656, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22363880

RESUMEN

Diabetes mellitus (DM) is a complex disease, being one of the most prevalent diseases worldwide. As a consequence, pregnancy-associated diabetes is increasingly common. Given the numerous studies about the influence of diabetes on offspring of diabetic rat dams, the neurological outcome is of outmost importance. This paper aimed at evaluating the neurofunctional performance of young male offspring of rat dams with diabetes induced by streptozotocin. Diabetes was induced in Wistar female rats by streptozotocin administration, while control groups received vehicle injection. At two-month survival period, male offspring from each group were randomized to the water maze Morris test, in order to assess their neurofunctional status. There was no significant difference between the groups as assessed by the Morris water maze test for spatial reference task. Our results point to the need of further investigation on the offspring neurofunctional performance.

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