Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Neurochem ; 157(6): 2106-2118, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33107046

RESUMEN

Modifications in the subunit composition of AMPA receptors (AMPARs) have been linked to the transition from physiological to pathological conditions in a number of contexts, including EtOH-induced neurotoxicity. Previous work from our laboratory showed that EtOH withdrawal causes CA1 pyramidal cell death in organotypic hippocampal slices and changes in the expression of AMPARs. Here, we investigated whether changes in expression and function of AMPARs may be causal for EtOH-induced neurotoxicity. To this aim, we examined the subunit composition, localization and function of AMPARs in hippocampal slices exposed to EtOH by using western blotting, surface expression assay, confocal microscopy and electrophysiology. We found that EtOH withdrawal specifically increases GluA1 protein signal in total homogenates, but not in the post-synaptic density-enriched fraction. This is suggestive of overall increase and redistribution of AMPARs to the extrasynaptic compartment. At functional level, AMPA-induced calcium influx was unexpectedly reduced, whereas AMPA-induced current was enhanced in CA1 pyramidal neurons following EtOH withdrawal, suggesting that increased AMPAR expression may lead to cell death because of elevated excitability, and not for a direct contribution on calcium influx. Finally, the neurotoxicity caused by EtOH withdrawal was attenuated by the non-selective AMPAR antagonist 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7-sulfonamide disodium salt as well as by the selective antagonist of GluA2-lacking AMPARs 1-naphthyl acetyl spermine. We conclude that EtOH neurotoxicity involves changes in expression, surface localization and functional properties of AMPARs, and propose GluA2-lacking AMPARs as amenable specific targets for the development of neuroprotective drugs in EtOH-withdrawal syndrome.


Asunto(s)
Etanol/toxicidad , Regulación de la Expresión Génica , Ácido Glutámico/metabolismo , Hipocampo/metabolismo , Receptores AMPA/metabolismo , Animales , Antagonistas de Aminoácidos Excitadores/farmacología , Femenino , Citometría de Flujo/métodos , Ácido Glutámico/análisis , Hipocampo/química , Hipocampo/efectos de los fármacos , Masculino , Técnicas de Cultivo de Órganos , Ratas , Ratas Wistar , Receptores AMPA/análisis , Receptores AMPA/antagonistas & inhibidores
2.
Eur J Neurosci ; 42(9): 2699-706, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26354486

RESUMEN

The selective vulnerability of substantia nigra pars compacta (SNc) dopaminergic (DA) neurons is an enigmatic trait of Parkinson's disease (PD), especially if compared to the remarkable resistance of closely related DA neurons in the neighboring ventral tegmental area (VTA). Overall evidence indicates that specific electrophysiological, metabolic and molecular factors underlie SNc vulnerability, although many pieces of the puzzle are still missing. In this respect, we recently demonstrated that 1-methyl-4-phenylpyridinium (MPP+), the active metabolite of the parkinsonizing toxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), alters the electrophysiological properties of SNc DA neurons in vitro by inhibiting the hyperpolarization-activated current (Ih). Here, we present an electrophysiological investigation of the functional role of Ih in the integration of synaptic inputs in identified SNc and VTA DA neurons, comparatively, in acute midbrain slices from TH-GFP mice. We show that pharmacological suppression of Ih increases the amplitude and decay time of excitatory postsynaptic potentials, leading to temporal summation of multiple excitatory potentials at somatic level. Importantly, these effects are quantitatively more evident in SNc DA neurons. We conclude that Ih regulates the responsiveness to excitatory synaptic transmission in SNc and VTA DA neurons differentially. Finally, we present the hypothesis that Ih loss of function may be linked to PD trigger mechanisms, such as mitochondrial failure and ATP depletion, and act in concert with SNc-specific synaptic connectivity to promote selective vulnerability.


Asunto(s)
Neuronas Dopaminérgicas/fisiología , Potenciales Postsinápticos Excitadores , Canales Regulados por Nucleótidos Cíclicos Activados por Hiperpolarización/fisiología , Porción Compacta de la Sustancia Negra/fisiología , Sumación de Potenciales Postsinápticos , Área Tegmental Ventral/fisiología , Animales , Dopamina/metabolismo , Neuronas Dopaminérgicas/metabolismo , Femenino , Masculino , Ratones , Ratones Transgénicos , Porción Compacta de la Sustancia Negra/metabolismo , Tirosina 3-Monooxigenasa/metabolismo , Área Tegmental Ventral/metabolismo
3.
New Microbiol ; 37(1): 97-101, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24531177

RESUMEN

We describe a case of a 64-year-old man with a history of ITP which had required several treatments including splenectomy, and with chronic hepatitis C virus (HCV) infection untreated due to severe thrombocytopenia. In March 2011, platelet count was 14,000/mmc and a thrombopoietic therapy with romiplostim was initiated at the dose of 2 mcg/kg/week that was increased to 8 mcg/kg/week. At week 32, platelet count was 65,000/mmc and an anti-HCV therapy with peginterferon and ribavirin was then started. At baseline laboratory tests indicated AST 99IU/l, ALT 125UI/l, HCV_RNA 3,220 UI/ml and HCV genotype 2a/2c. An early virological response (EVR) with normalization of transaminases in the course of antiviral therapy, such as a sustained virological response (SVR) after its interruption were recorded. Therefore a satisfactory platelet count (range 54.000-179.000/mmc) at the dose of 4 mcg/week during antiviral therapy, such as at the dose of 2 mcg/kg/week after antiviral interruption (range 65.000-292.000/mmc) was recorded. Romiplostim proved effective and safe in the course of antiviral treatment. Therefore it permitted the start of anti-HCV therapy despite severe thrombocytopenia and also avoided any peg-interferon dosage modification or discontinuation. Further prospective studies in larger patient cohort should be encouraged to validate this strategy.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/efectos de los fármacos , Hepatitis C Crónica/tratamiento farmacológico , Receptores Fc/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Trombocitopenia/tratamiento farmacológico , Trombopoyetina/uso terapéutico , Quimioterapia Combinada , Hepatitis C Crónica/virología , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Ribavirina/uso terapéutico , Resultado del Tratamiento
4.
Front Cell Neurosci ; 18: 1258793, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38799987

RESUMEN

Large-scale cortical dynamics play a crucial role in many cognitive functions such as goal-directed behaviors, motor learning and sensory processing. It is well established that brain states including wakefulness, sleep, and anesthesia modulate neuronal firing and synchronization both within and across different brain regions. However, how the brain state affects cortical activity at the mesoscale level is less understood. This work aimed to identify the cortical regions engaged in different brain states. To this end, we employed group ICA (Independent Component Analysis) to wide-field imaging recordings of cortical activity in mice during different anesthesia levels and the awake state. Thanks to this approach we identified independent components (ICs) representing elements of the cortical networks that are common across subjects under decreasing levels of anesthesia toward the awake state. We found that ICs related to the retrosplenial cortices exhibited a pronounced dependence on brain state, being most prevalent in deeper anesthesia levels and diminishing during the transition to the awake state. Analyzing the occurrence of the ICs we found that activity in deeper anesthesia states was characterized by a strong correlation between the retrosplenial components and this correlation decreases when transitioning toward wakefulness. Overall these results indicate that during deeper anesthesia states coactivation of the posterior-medial cortices is predominant over other connectivity patterns, whereas a richer repertoire of dynamics is expressed in lighter anesthesia levels and the awake state.

5.
Biochem Pharmacol ; 226: 116409, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38969300

RESUMEN

Epilepsy is a central nervous system (CNS) disorder causing repeated seizures due to a transient excessive or synchronous alteration in the electrical activity of the brain. Several neurological disorders have been associated to gluten-related diseases (GRD), including epilepsy. However, the molecular mechanisms that associate GRD and epileptogenesis are still unknown. Our previous data have shown that the gliadin peptide 31-43 (p31-43) enhanced number and duration of seizures induced by kainate in mice and exacerbated CA3-kainate-induced neurotoxicity in organotypic hippocampal slices. Here, we investigated whether another important gliadin peptide p57-68 may exerts effects similar to p31-43 on kainate-induced neurotoxicity. We find that both peptides exacerbate kainate-induced damage in the CA3 region once simultaneously challenged. However, after pre-incubation, p31-43 additionally exacerbates neurotoxicity in the CA1 region, while p57-68 does not. These data suggested differential intracellular mechanisms activated by the peptides. Indeed, analysing intracellular signalling pathways we discover that p31-43 induces significant intracellular changes, including increased phosphorylation of Akt, Erk1/2, and p65, decreased p38 phosphorylation, and deacetylation of nuclear histone-3. Based on these observations, we demonstrate that p31-43 likely activates specific intracellular signaling pathways involved in neuronal excitability, inflammation, and epigenetic regulation, which may contribute to its exacerbation of kainate-induced neurotoxicity. In contrast, p57-68 appears to exert its effects through different mechanisms. Further research is necessary to elucidate the precise mechanisms by which these peptides influence neurotoxicity and understand their implications for neurological disorders.


Asunto(s)
Epilepsia , Gliadina , Animales , Epilepsia/metabolismo , Epilepsia/inducido químicamente , Gliadina/toxicidad , Gliadina/metabolismo , Fragmentos de Péptidos/toxicidad , Fragmentos de Péptidos/metabolismo , Ácido Kaínico/toxicidad , Ratones , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos
6.
iScience ; 27(5): 109692, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38689637

RESUMEN

Sensory information must be integrated across a distributed brain network for stimulus processing and perception. Recent studies have revealed specific spatiotemporal patterns of cortical activation for the early and late components of sensory-evoked responses, which are associated with stimulus features and perception, respectively. Here, we investigated how the brain state influences the sensory-evoked activation across the mouse cortex. We utilized isoflurane to modulate the brain state and conducted wide-field calcium imaging of Thy1-GCaMP6f mice to monitor distributed activation evoked by multi-whisker stimulation. Our findings reveal that the level of anesthesia strongly shapes the spatiotemporal features and the functional connectivity of the sensory-activated network. As anesthesia levels decrease, we observe increasingly complex responses, accompanied by the emergence of the late component within the sensory-evoked response. The persistence of the late component under anesthesia raises new questions regarding the potential existence of perception during unconscious states.

7.
Cell Rep Methods ; 4(1): 100681, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38183979

RESUMEN

Neuroscience is moving toward a more integrative discipline where understanding brain function requires consolidating the accumulated evidence seen across experiments, species, and measurement techniques. A remaining challenge on that path is integrating such heterogeneous data into analysis workflows such that consistent and comparable conclusions can be distilled as an experimental basis for models and theories. Here, we propose a solution in the context of slow-wave activity (<1 Hz), which occurs during unconscious brain states like sleep and general anesthesia and is observed across diverse experimental approaches. We address the issue of integrating and comparing heterogeneous data by conceptualizing a general pipeline design that is adaptable to a variety of inputs and applications. Furthermore, we present the Collaborative Brain Wave Analysis Pipeline (Cobrawap) as a concrete, reusable software implementation to perform broad, detailed, and rigorous comparisons of slow-wave characteristics across multiple, openly available electrocorticography (ECoG) and calcium imaging datasets.


Asunto(s)
Ondas Encefálicas , Programas Informáticos , Encéfalo , Sueño , Mapeo Encefálico/métodos
8.
Sci Rep ; 13(1): 3183, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36823228

RESUMEN

Brain states, such as wake, sleep, or different depths of anesthesia are usually assessed using electrophysiological techniques, such as the local field potential (LFP) or the electroencephalogram (EEG), which are ideal signals for detecting activity patterns such as asynchronous or oscillatory activities. However, it is technically challenging to have these types of measures during calcium imaging recordings such as two-photon or wide-field techniques. Here, using simultaneous two-photon and LFP measurements, we demonstrate that despite the slower dynamics of the calcium signal, there is a high correlation between the LFP and two-photon signals taken from the neuropil outside neuronal somata. Moreover, we find the calcium signal to be systematically delayed from the LFP signal, and we use a model to show that the delay between the two signals is due to the physical distance between the recording sites. These results suggest that calcium signals alone can be used to detect activity patterns such as slow oscillations and ultimately assess the brain state and level of anesthesia.


Asunto(s)
Anestesia , Calcio , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Electroencefalografía , Sueño/fisiología , Calcio de la Dieta
9.
Commun Biol ; 6(1): 266, 2023 03 13.
Artículo en Inglés | MEDLINE | ID: mdl-36914748

RESUMEN

The development of novel techniques to record wide-field brain activity enables estimation of data-driven models from thousands of recording channels and hence across large regions of cortex. These in turn improve our understanding of the modulation of brain states and the richness of traveling waves dynamics. Here, we infer data-driven models from high-resolution in-vivo recordings of mouse brain obtained from wide-field calcium imaging. We then assimilate experimental and simulated data through the characterization of the spatio-temporal features of cortical waves in experimental recordings. Inference is built in two steps: an inner loop that optimizes a mean-field model by likelihood maximization, and an outer loop that optimizes a periodic neuro-modulation via direct comparison of observables that characterize cortical slow waves. The model reproduces most of the features of the non-stationary and non-linear dynamics present in the high-resolution in-vivo recordings of the mouse brain. The proposed approach offers new methods of characterizing and understanding cortical waves for experimental and computational neuroscientists.


Asunto(s)
Ondas Encefálicas , Electroencefalografía , Animales , Ratones , Electroencefalografía/métodos , Encéfalo , Modelos Neurológicos , Simulación por Computador
10.
Recenti Prog Med ; 103(7-8): 275-8, 2012.
Artículo en Italiano | MEDLINE | ID: mdl-22825382

RESUMEN

Antibiotic resistance in Klebsiella pneumoniae strains is an increasing problem in a lot of hospitals. It is a public health emergency because it relates with high mortality rate among patients in Intensive Care Unit (ICU). From 1/1/2009 to 31/08/2010, in ICU of SS Annunziata Hospital of Taranto, 140 isolated Klebsiella pneumoniae strains were detected. The strain identification and antimicrobial susceptibility testing were performed using a Vitek2 automated system. These isolate showed a low level of susceptibility to levofloxacin (3.4%), ciprofloxacin (6.2%), ceftazidime (2.8%) and piperacillin/tazobactam (8%). We reported also that the 10% and 13.9% of them were susceptible to meropenem and imipenem. An anti-Klebsiella pneumoniae activity in vitro to tigecycline was present in 64.6% of isolates while almost all strains (56/58) tested to colistin were susceptible. In order to our data of worryng high multiclass drug resistance including tygecicline, it needs to apply appropriate measures of surveillance and antibiotic prescription to avoid rapid spread of these mutiresistant strains in other areas.


Asunto(s)
Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana Múltiple , Unidades de Cuidados Intensivos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Minociclina/análogos & derivados , Infección Hospitalaria/epidemiología , Humanos , Italia/epidemiología , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Minociclina/farmacología , Prevalencia , Tigeciclina
11.
Cell Rep ; 41(6): 111627, 2022 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-36351410

RESUMEN

In rodent motor cortex, the rostral forelimb area (RFA) and the caudal forelimb area (CFA) are major actors in orchestrating the control of complex forelimb movements. However, their intrinsic connectivity and reciprocal functional organization are still unclear, limiting our understanding of how the brain coordinates and executes voluntary movements. Here, we causally probe cortical connectivity and activation patterns triggered by transcranial optogenetic stimulation of ethologically relevant complex movements exploiting a large-scale all-optical method in awake mice. Results show specific activation features for each movement class, providing evidence for a segregated functional organization of CFA and RFA. Importantly, we identify a second discrete lateral grasping representation area, namely the lateral forelimb area (LFA), with unique connectivity and activation patterns. Therefore, we propose the LFA as a distinct forelimb representation in the mouse somatotopic motor map.


Asunto(s)
Corteza Motora , Ratones , Animales , Corteza Motora/fisiología , Miembro Anterior/fisiología , Optogenética , Movimiento/fisiología , Mapeo Encefálico , Estimulación Eléctrica
12.
J Biophotonics ; 15(4): e202100256, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35000289

RESUMEN

Two-photon (2P) excitation is a cornerstone approach widely employed in neuroscience microscopy for deep optical access and sub-micrometric-resolution light targeting into the brain. However, besides structural and functional imaging, 2P optogenetic stimulations are less routinary, especially in 3D. This is because of the adopted scanning systems, often feebly effective, slow and mechanically constricted. Faster illumination can be achieved through acousto-optic deflectors (AODs) although their applicability to large volumes excitation has been limited by large efficiency drop along the optical axis. Here, we present a new AOD-based scheme for 2P 3D scanning that improves the power delivery between different illumination planes. We applied this approach to photostimulate an optogenetic actuator in zebrafish larvae, demonstrating the method efficiency observing increased activity responses and uniform activation probabilities from neuronal clusters addressed in the volume. This novel driving scheme can open to new AOD applications in neuroscience, allowing more effective 3D interrogation in large neuronal networks.


Asunto(s)
Neuronas , Pez Cebra , Animales , Encéfalo/diagnóstico por imagen , Optogenética , Estimulación Luminosa/métodos
13.
Blood Purif ; 29(4): 383-9, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20484899

RESUMEN

BACKGROUND: Long-term treatment with low-density lipoprotein (LDL) apheresis (LA) has been shown to reduce the incidence of cardiovascular events in patients affected by familial hypercholesterolemia (FH). Data from experimental studies suggest that circulating endothelial progenitor cells (EPCs) can repair the vascular lesions caused by atherosclerosis. Since a reduction of these cells has been demonstrated to predict atherosclerosis progression, the aim of this study was to verify whether LA can increase the percentage of EPCs. METHODS: In 15 patients affected by FH periodically treated with LA, the percentage of EPCs was determined before and after performing LA, and compared with the values of 15 control subjects and 15 hypercholesterolemic patients treated with statins. RESULTS: Significant differences were found in FH patients between the pre-apheresis percentages of CD34+/KDR+, defined as EPCs by a wide consensus of opinion, and the values found 24 h after the procedures (0.00868 +/- 0.003 vs. 0.01009 +/- 0.002%, p < 0.005). Instead, the percentages of CD34+/KDR+/CD133+, considered as an immature subset of EPCs, remained substantially unchanged. However, a significant reduction in the percentage of EPCs was observed in both patient groups as compared to the controls, at all the assessment times. CONCLUSION: In the short-term LA seems to stimulate mobilization of CD34+/KDR+ cells. Hypercholesterolemic patients show a lower percentage of EPCs than controls. There were no differences in the EPCs percentages between the 2 patients groups, despite the fact that LDL cholesterol levels were higher in the group undergoing LA.


Asunto(s)
Eliminación de Componentes Sanguíneos/métodos , Células Endoteliales , Hiperlipoproteinemia Tipo II/terapia , Lipoproteínas LDL/aislamiento & purificación , Células Madre , Adulto , Estudios de Casos y Controles , Recuento de Células , LDL-Colesterol/sangre , Femenino , Movilización de Célula Madre Hematopoyética , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Masculino , Persona de Mediana Edad , Factores de Tiempo
14.
New Microbiol ; 33(3): 271-4, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20954448

RESUMEN

The introduction of targeted immunotherapies has greatly improved the therapeutic options of several inflammatory diseases such as psoriatic arthritis. However treatment-related opportunistic infections and viral reactivations may still occur. We describe a case of varicella zoster virus (VZV) encephalitis due to the reactivation of latent VZV infection during a long therapy with the anti-tumor necrosis factor-alpha (TNF-alpha) drug Adalimumab. The low incidence of VZV encephalitis in patients treated with biological agents does not justify VZV serological screening in these subjects, but careful monitoring of the patients is recommended to recognize early signs and symptoms of herpes zoster to start prompt antiviral therapy to prevent associated complications.


Asunto(s)
Antiinflamatorios/efectos adversos , Anticuerpos Monoclonales/efectos adversos , Artritis Psoriásica/tratamiento farmacológico , Encefalitis por Varicela Zóster/etiología , Herpesvirus Humano 3/fisiología , Factor de Necrosis Tumoral alfa/efectos adversos , Adalimumab , Adulto , Antiinflamatorios/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Artritis Psoriásica/complicaciones , Femenino , Herpesvirus Humano 3/efectos de los fármacos , Humanos , Factor de Necrosis Tumoral alfa/uso terapéutico , Activación Viral/efectos de los fármacos
15.
Recenti Prog Med ; 101(7-8): 307, 2010.
Artículo en Italiano | MEDLINE | ID: mdl-20842960

RESUMEN

At today, neurologic desorders associated with novel influenza A (H1N1) virus were reported only in children but not in adult. We report two cases of encephalitis associated to H1N1 virus infection occurred in females of age 28 and 37 years. In both cases disease was less severe without neurologic sequelae. In one case PCR analysis of CSF sample showed a positivity for HSV1. Novel influenza A (H1N1) viral RNA by real time PCR was detected in nasopharyngeal specimens.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Adulto , Factores de Edad , Líquido Cefalorraquídeo/virología , Encefalitis/líquido cefalorraquídeo , Encefalitis/etiología , Femenino , Humanos , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Nasofaringe/virología , Reacción en Cadena de la Polimerasa , ARN Viral/análisis
16.
Front Syst Neurosci ; 14: 31, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32733210

RESUMEN

Being able to replicate real experiments with computational simulations is a unique opportunity to refine and validate models with experimental data and redesign the experiments based on simulations. However, since it is technically demanding to model all components of an experiment, traditional approaches to modeling reduce the experimental setups as much as possible. In this study, our goal is to replicate all the relevant features of an experiment on motor control and motor rehabilitation after stroke. To this aim, we propose an approach that allows continuous integration of new experimental data into a computational modeling framework. First, results show that we could reproduce experimental object displacement with high accuracy via the simulated embodiment in the virtual world by feeding a spinal cord model with experimental registration of the cortical activity. Second, by using computational models of multiple granularities, our preliminary results show the possibility of simulating several features of the brain after stroke, from the local alteration in neuronal activity to long-range connectivity remodeling. Finally, strategies are proposed to merge the two pipelines. We further suggest that additional models could be integrated into the framework thanks to the versatility of the proposed approach, thus allowing many researchers to achieve continuously improved experimental design.

17.
Thyroid ; 28(10): 1387-1397, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30129879

RESUMEN

BACKGROUND: 3-Iodothyroacetic acid (TA1) is among the thyroid hormone (T3) metabolites that can acutely modify behavior in mice. This study aimed to investigate whether TA1 is also able to reduce neuron hyper-excitability and protect from excitotoxic damage. METHODS: CD1 male mice were treated intraperitoneally with saline solution or TA1 (4, 7, 11, or 33 µg/kg) before receiving 90 mg/kg pentylenetrazole subcutaneously. The following parameters were measured: latency to first seizure onset, number of mice experiencing seizures, hippocampal levels of c-fos, and PI3K/AKT activation levels. Organotypic hippocampal slices were exposed to vehicle or to 5 µM kainic acid (KA) in the absence or presence of 0.01-10 µM TA1. In another set of experiments, slices were exposed to vehicle or 5 µM KA in the absence or presence of 10 µM T3, 3,5,3'-triiodothyroacetic acid (TRIAC), T1AM, thyronamine (T0AM), or thyroacetic acid (TA0). Neuronal cell death was measured fluorimetically. The ability of TA1 and T3, TRIAC, T1AM, T0A, and TA0 to activate the PI3K/AKT cascade was evaluated by Western blot. The effect of TA1 on KA-induced currents in CA3 neurons was evaluated by patch clamp recordings on acute hippocampal slices. RESULTS: TA1 (7 and 11 µg/kg) significantly reduced the number of mice showing convulsions and increased their latency of onset, restored pentylenetrazole-induced reduction of hippocampal c-fos levels, activated the PI3K/AKT, and reduced GSK-3ß activity. In rat organotypic hippocampal slices, TA1 reduced KA-induced cell death by activating the PI3K/AKT cascade and increasing GSK-3ß phosphorylation levels. Protection against KA toxicity was also exerted by T3 and other T3 metabolites studied. TA1 did not interact at KA receptors. Both the anticonvulsant and neuroprotective effects of TA1 were abolished by pretreating mice or organotypic hippocampal slices with pyrilamine, an histamine type 1 receptor antagonist (10 mg/kg or 1 µM, respectively). CONCLUSIONS: TA1 exerts anticonvulsant activity and is neuroprotective in vivo and in vitro. These findings extend the current knowledge on the pharmacological profile of TA1 and indicate possible novel clinical use for this T3 metabolite.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Hipocampo/efectos de los fármacos , Fármacos Neuroprotectores/uso terapéutico , Convulsiones/tratamiento farmacológico , Tironinas/uso terapéutico , Animales , Anticonvulsivantes/farmacología , Muerte Celular/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Convulsiones/metabolismo , Transducción de Señal/efectos de los fármacos
18.
Neurochem Int ; 115: 31-36, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29032008

RESUMEN

3-iodothyroacetic acid (TA1) is among the by-products of thyroid hormone metabolism suspected to mediate the non-genomic effects of the hormone (T3). We aim to investigate whether TA1 systemically administered to mice stimulated mice wakefulness, an effect already described for T3 and for another T3 metabolite (i.e. 3-iodothryonamine; T1AM), and whether TA1 interacted at GABA-A receptors (GABA-AR). Mice were pre-treated with either saline (vehicle) or TA1 (1.32, 4 and 11 µg/kg) and, after 10 min, they received ethanol (3.5 g/kg, i.p.). In another set of experiments, TA1 was administered 5 min after ethanol. The latency of sleep onset and the time of sleep duration were recorded. Voltage-clamp experiments to evaluate the effect of 1 µM TA1 on bicuculline-sensitive currents in acute rat hippocampal slice neurons and binding experiments evaluating the capacity of 1, 10, 100 µM TA1 to displace [3H]flumazenil from mice brain membranes were also performed. 4 µg/kg TA1 increases the latency of onset and at 1.32 and 4 µg/kg it reduces the duration of ethanol-induced sleep only if administered before ethanol. TA1 does not functionally interact at GABA-AR. Overall these results indicate a further similarity between the pharmacological profile of TA1 and that of T1AM.


Asunto(s)
Antitiroideos/farmacología , Hipocampo/efectos de los fármacos , Receptores de GABA-A/efectos de los fármacos , Tironinas/farmacología , Animales , Etanol/farmacología , Hipocampo/metabolismo , Hipnóticos y Sedantes/farmacología , Masculino , Ratones , Ratas Wistar , Receptores de GABA-A/metabolismo , Hormonas Tiroideas/metabolismo , Tironinas/metabolismo
19.
Front Pharmacol ; 9: 1252, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30467478

RESUMEN

A prominent role of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels has been suggested based on their expression and (dys)function in dorsal root ganglion (DRG) neurons, being likely involved in peripheral nociception. Using HCN blockers as antinociceptive drugs is prevented by the widespread distribution of these channels. However, tissue-specific expression of HCN isoforms varies significantly, HCN1 and HCN2 being considered as major players in DRG excitability. We characterized the pharmacological effect of a novel compound, MEL55A, able to block selectively HCN1/HCN2 isoforms, on DRG neuron excitability in-vitro and for its antiallodynic properties in-vivo. HEK293 cells expressing HCN1, HCN2, or HCN4 isoforms were used to verify drug selectivity. The pharmacological profile of MEL55A was tested on mouse DRG neurons by patch-clamp recordings, and in-vivo in oxaliplatin-induced neuropathy by means of thermal hypersensitivity. Results were compared to the non-isoform-selective drug, ivabradine. MEL55A showed a marked preference toward HCN1 and HCN2 isoforms expressed in HEK293, with respect to HCN4. In cultured DRG, MEL55A reduced I h amplitude, both in basic conditions and after stimulation by forskolin, and cell excitability, its effect being quantitatively similar to that observed with ivabradine. MEL55A was able to relieve chemotherapy-induced neuropathic pain. In conclusion, selective blockade of HCN1/HCN2 channels, over HCN4 isoform, was able to modulate electrophysiological properties of DRG neurons similarly to that reported for classical I h blockers, ivabradine, resulting in a pain-relieving activity. The availability of small molecules with selectivity toward HCN channel isoforms involved in nociception might represent a safe and effective strategy against chronic pain.

20.
Br J Pharmacol ; 175(2): 272-283, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28320070

RESUMEN

BACKGROUND AND PURPOSE: Dexpramipexole, a drug recently tested in patients with amyotrophic lateral sclerosis (ALS,) is able to bind F1Fo ATP synthase and increase mitochondrial ATP production. Here, we have investigated its effects on experimental ischaemic brain injury. EXPERIMENTAL APPROACH: The effects of dexpramipexole on bioenergetics, Ca2+ fluxes, electrophysiological functions and death were evaluated in primary neural cultures and hippocampal slices exposed to oxygen-glucose deprivation (OGD). Effects on infarct volumes and neurological functions were also evaluated in mice following proximal or distal middle cerebral artery occlusion (MCAo). Distribution of dexpramipexole within the ischaemic brain was evaluated by means of mass spectrometry imaging. KEY RESULTS: Dexpramipexole increased mitochondrial ATP production in cultured neurons or glia and reduces energy failure, prevents intracellular Ca2+ overload and affords cytoprotection when cultures are exposed to OGD. This compound also counteracted ATP depletion, mitochondrial swelling, anoxic depolarization, loss of synaptic activity and neuronal death in hippocampal slices subjected to OGD. Post-ischaemic treatment with dexpramipexole, at doses consistent with those already used in ALS patients, reduced brain infarct size and ameliorated neuroscore in mice subjected to transient or permanent MCAo. Notably, the concentrations of dexpramipexole reached within the ischaemic penumbra equalled those found neuroprotective in vitro. CONCLUSION AND IMPLICATIONS: Dexpramipexole, a compound able to increase mitochondrial F1Fo ATP-synthase activity reduced ischaemic brain injury. These findings, together with the excellent brain penetration and favourable safety profile in humans, make dexpramipexole a drug with realistic translational potential for the treatment of stroke. LINKED ARTICLES: This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.


Asunto(s)
Benzotiazoles/farmacología , Benzotiazoles/uso terapéutico , Metabolismo Energético/efectos de los fármacos , Fármacos Neuroprotectores/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Adenosina Trifosfato/metabolismo , Animales , Benzotiazoles/farmacocinética , Calcio/metabolismo , Muerte Celular/efectos de los fármacos , Potenciales Evocados/fisiología , Hipocampo/metabolismo , Hipocampo/fisiología , Hipocampo/ultraestructura , Infarto de la Arteria Cerebral Media , Masculino , Ratones , Mitocondrias/metabolismo , Neuronas/fisiología , Fármacos Neuroprotectores/farmacocinética , Fármacos Neuroprotectores/farmacología , Pramipexol , Cultivo Primario de Células , Ratas , Accidente Cerebrovascular/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA