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1.
Nat Commun ; 12(1): 1423, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33658509

RESUMEN

In the mammalian hippocampus, adult-born granule cells (abGCs) contribute to the function of the dentate gyrus (DG). Disruption of the DG circuitry causes spontaneous recurrent seizures (SRS), which can lead to epilepsy. Although abGCs contribute to local inhibitory feedback circuitry, whether they are involved in epileptogenesis remains elusive. Here, we identify a critical window of activity associated with the aberrant maturation of abGCs characterized by abnormal dendrite morphology, ectopic migration, and SRS. Importantly, in a mouse model of temporal lobe epilepsy, silencing aberrant abGCs during this critical period reduces abnormal dendrite morphology, cell migration, and SRS. Using mono-synaptic tracers, we show silencing aberrant abGCs decreases recurrent CA3 back-projections and restores proper cortical connections to the hippocampus. Furthermore, we show that GABA-mediated amplification of intracellular calcium regulates the early critical period of activity. Our results demonstrate that aberrant neurogenesis rewires hippocampal circuitry aggravating epilepsy in mice.


Asunto(s)
Epilepsia/fisiopatología , Hipocampo/fisiopatología , Neurogénesis/fisiología , Animales , Calcio/metabolismo , Clozapina/análogos & derivados , Clozapina/farmacología , Modelos Animales de Enfermedad , Electroencefalografía , Epilepsia del Lóbulo Temporal/fisiopatología , Femenino , Ratones Endogámicos C57BL , Ratones Transgénicos , Neurogénesis/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Pilocarpina/farmacología , Retroviridae/genética , Convulsiones/fisiopatología , Ácido gamma-Aminobutírico/metabolismo
2.
Nat Commun ; 12(1): 1398, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33658519

RESUMEN

We previously identified a causal link between a rare patient mutation in DISC1 (disrupted-in-schizophrenia 1) and synaptic deficits in cortical neurons differentiated from isogenic patient-derived induced pluripotent stem cells (iPSCs). Here we find that transcripts related to phosphodiesterase 4 (PDE4) signaling are significantly elevated in human cortical neurons differentiated from iPSCs with the DISC1 mutation and that inhibition of PDE4 or activation of the cAMP signaling pathway functionally rescues synaptic deficits. We further generated a knock-in mouse line harboring the same patient mutation in the Disc1 gene. Heterozygous Disc1 mutant mice exhibit elevated levels of PDE4s and synaptic abnormalities in the brain, and social and cognitive behavioral deficits. Pharmacological inhibition of the PDE4 signaling pathway rescues these synaptic, social and cognitive behavioral abnormalities. Our study shows that patient-derived isogenic iPSC and humanized mouse disease models are integral and complementary for translational studies with a better understanding of underlying molecular mechanisms.


Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/genética , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Proteínas del Tejido Nervioso/genética , Inhibidores de Fosfodiesterasa 4/farmacología , Esquizofrenia/genética , Animales , Conducta Animal/efectos de los fármacos , Corteza Cerebral/fisiología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Humanos , Masculino , Ratones Mutantes , Mutación , Neuronas/efectos de los fármacos , Rolipram/farmacología , Esquizofrenia/patología , Sinapsis/efectos de los fármacos , Sinapsis/fisiología
3.
Int J Nanomedicine ; 16: 1423-1434, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33654394

RESUMEN

Background: Interleukin-1ß (IL-1)-treated mesenchymal stem cells (MSCs) and IL-1-MSCs-conditioned medium (CM) exert anti-inflammatory roles. Astrocytes are essential for the modulation of synaptic activity and neuronal homeostasis in the brain. Exosomes are the critical mediators in intercellular communication. However, the mechanism underlying the anti-inflammatory effect of IL-1-treated MSCs remains unknown. Methods: In this study, exosomes (IL-1-Exo) were isolated from IL-1-treated MSCs. In addition, lipopolysaccharide (LPS)-treated hippocampal astrocytes and status epilepticus (SE) mice were treated with IL-1-Exo. Inflammatory activity, astrogliosis, and cognitive performance were measured to determine the effect of IL-1-Exo on inflammation. Results: The results revealed that IL-1-Exo significantly inhibited LPS-induced astrogliosis and inflammatory responses of astrocytes. Also, IL-1-Exo reversed the LPS-induced effect on calcium signaling. The Nrf2 signaling pathway was associated with the effect of IL-1-Exo in LPS-treated astrocytes. Furthermore, IL-1-Exo reduced the inflammatory response and improved the cognitive performance of SE mice. Conclusion: The results suggest that IL-1-Exo inhibited LPS-induced inflammatory responses in astrocytes and SE mice and that the effect of IL-1-Exo was primarily mediated through the Nrf-2 signaling pathway. This study provides a new understanding of the molecular mechanism of inflammation-associated brain diseases and an avenue to develop nanotherapeutic agents for the treatment of inflammatory conditions in the brain.


Asunto(s)
Astrocitos/patología , Exosomas/metabolismo , Hipocampo/patología , Inflamación/terapia , Interleucina-1beta/farmacología , Células Madre Mesenquimatosas/citología , Factor 2 Relacionado con NF-E2/metabolismo , Transducción de Señal , Animales , Animales Recién Nacidos , Antiinflamatorios/farmacología , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Conducta Animal/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Exosomas/efectos de los fármacos , Exosomas/ultraestructura , Humanos , Inflamación/patología , Lipopolisacáridos , Masculino , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Transducción de Señal/efectos de los fármacos , Estado Epiléptico/patología
4.
Ecotoxicol Environ Saf ; 212: 112018, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33550076

RESUMEN

The underlying mechanisms of microRNAs (miRNAs) in regulating nanoplastic toxicity are still largely unclear in organisms. In nanopolystyrene (NPS) exposed Caenorhabditis elegans, the expression of mir-76 (a neuronal miRNA) was significantly decreased, and the mir-76 mutant was resistant to the toxicity of NPS. The aim of this study was to determine the molecular basis of mir-76 in controlling NPS toxicity in nematodes. The mir-76 mutation increased expression of glb-10 encoding a globin protein in NPS (1 µg/L) exposed nematodes. Exposure to NPS (1-100 µg/L) increased the glb-10 expression, and the glb-10(RNAi) worm was susceptible to NPS toxicity in inducing reactive oxygen species (ROS) production and in decreasing locomotion behavior. Using ROS production and locomotion behavior as endpoints, mutation of glb-10 inhibited resistance of mir-76 mutant to NPS toxicity, and neuronal overexpression of mir-76 inhibited the resistance to NPS toxicity in nematodes overexpressing neuronal glb-10 containing 3' untranslated region (3'UTR). Thus, GLB-10 functioned as a target of mir-76 in the neurons to regulate the NPS toxicity. Moreover, a signaling cascade of HRG-7-HRG-5 required for the control of heme homeostasis was identified to function downstream of neuronal GLB-10 to regulate the NPS toxicity. In this signaling cascade, the neuronal HRG-7 regulated the NPS toxicity by antagonizing function of intestinal HRG-5. Furthermore, in the intestine, HRG-5 controlled NPS toxicity by inhibiting functions of hypoxia-inducible transcriptional factor HIF-1 and transcriptional factor ELT-2. Our results highlight the crucial function of heme homeostasis related signaling in regulating the NPS toxicity in organisms.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/efectos de los fármacos , Hemo/metabolismo , Homeostasis , MicroARNs/genética , Nanoestructuras/toxicidad , Poliestirenos/toxicidad , Animales , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Intestinos/efectos de los fármacos , Nanoestructuras/química , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Poliestirenos/química , Interferencia de ARN , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal
6.
J Vis Exp ; (167)2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33554967

RESUMEN

Excitotoxic necrosis is a leading form of neurodegeneration. This process of regulated necrosis is triggered by the synaptic accumulation of the neurotransmitter glutamate, and the excessive stimulation of its postsynaptic receptors. However, information on the subsequent molecular events that culminate in the distinct neuronal swelling morphology of this type of neurodegeneration is lacking. Other aspects, such as changes in specific subcellular compartments, or the basis for the differential cellular vulnerability of distinct neuronal subtypes, remain under-explored. Furthermore, a range of factors that come into play in studies that use in vitro or ex vivo preparations might modify and distort the natural progression of this form of neurodegeneration. It is therefore important to study excitotoxic necrosis in live animals by monitoring the effects of interventions that regulate the extent of neuronal necrosis in the genetically amenable and transparent model system of the nematode Caenorhabditis elegans. This protocol describes methods of studying excitotoxic necrosis in C. elegans neurons, combining optical, genetic, and molecular analysis. To induce excitotoxic conditions in C. elegans, a knockout of a glutamate transporter gene (glt-3) is combined with a neuronal sensitizing genetic background (nuls5 [Pglr-1::GαS(Q227L)]) to produce glutamate receptor hyperstimulation and neurodegeneration. Nomarski differential interference contrast (DIC), fluorescent, and confocal microscopy in live animals are methods used to quantify neurodegeneration, follow subcellular localization of fluorescently labeled proteins, and quantify mitochondrial morphology in the degenerating neurons. Neuronal Fluorescence Activated Cell Sorting (FACS) is used to distinctly sort at-risk neurons for cell-type specific transcriptomic analysis of neurodegeneration. A combination of live imaging and FACS methods as well as the benefits of the C. elegans model organism allow researchers to leverage this system to obtain reproducible data with a large sample size. Insights from these assays could translate to novel targets for therapeutic intervention in neurodegenerative diseases.


Asunto(s)
Caenorhabditis elegans/citología , Imagenología Tridimensional , Degeneración Nerviosa/diagnóstico por imagen , Degeneración Nerviosa/patología , Neurotoxinas/toxicidad , Envejecimiento/patología , Crianza de Animales Domésticos , Animales , Apoptosis , Tampones (Química) , Caenorhabditis elegans/efectos de los fármacos , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animales de Enfermedad , Citometría de Flujo , Ácido Glutámico/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/patología , Necrosis , Neuronas/efectos de los fármacos , Neuronas/patología , Neuroprotección/efectos de los fármacos , ARN/aislamiento & purificación , Factores de Riesgo , Transcriptoma/genética
7.
Nat Commun ; 12(1): 1033, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33589615

RESUMEN

Clinical trials of novel therapeutics for Alzheimer's Disease (AD) have consumed a large amount of time and resources with largely negative results. Repurposing drugs already approved by the Food and Drug Administration (FDA) for another indication is a more rapid and less expensive option. We present DRIAD (Drug Repurposing In AD), a machine learning framework that quantifies potential associations between the pathology of AD severity (the Braak stage) and molecular mechanisms as encoded in lists of gene names. DRIAD is applied to lists of genes arising from perturbations in differentiated human neural cell cultures by 80 FDA-approved and clinically tested drugs, producing a ranked list of possible repurposing candidates. Top-scoring drugs are inspected for common trends among their targets. We propose that the DRIAD method can be used to nominate drugs that, after additional validation and identification of relevant pharmacodynamic biomarker(s), could be readily evaluated in a clinical trial.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Drogas en Investigación/farmacología , Aprendizaje Automático , Proteínas del Tejido Nervioso/genética , Fármacos Neuroprotectores/farmacología , Nootrópicos/farmacología , Medicamentos bajo Prescripción/farmacología , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Reposicionamiento de Medicamentos , Drogas en Investigación/química , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Ensayos Analíticos de Alto Rendimiento , Humanos , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Fármacos Neuroprotectores/química , Nootrópicos/química , Farmacogenética/métodos , Farmacogenética/estadística & datos numéricos , Polifarmacología , Medicamentos bajo Prescripción/química , Cultivo Primario de Células , Índice de Severidad de la Enfermedad
8.
Nat Neurosci ; 24(3): 326-330, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33603228

RESUMEN

By investigating the topology of neuronal co-activity, we found that mnemonic information spans multiple operational axes in the mouse hippocampus network. High-activity principal cells form the core of each memory along a first axis, segregating spatial contexts and novelty. Low-activity cells join co-activity motifs across behavioral events and enable their crosstalk along two other axes. This reveals an organizational principle for continuous integration and interaction of hippocampal memories.


Asunto(s)
Condicionamiento Operante/fisiología , Hipocampo/fisiología , Memoria/fisiología , Red Nerviosa/fisiología , Neuronas/fisiología , Sacarosa/administración & dosificación , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Animales , Condicionamiento Operante/efectos de los fármacos , Hipocampo/efectos de los fármacos , Memoria/efectos de los fármacos , Ratones , Red Nerviosa/efectos de los fármacos , Neuronas/efectos de los fármacos
9.
Ecotoxicol Environ Saf ; 214: 112005, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33640725

RESUMEN

Exposure to fine particulate matter (PM2.5) is implicated in neurodevelopmental disorders including cognitive decline, attention-deficit/hyperactivity disorder, and autism spectrum disorder. However, the specific molecular mechanisms by which PM2.5 impacts neurodevelopment are poorly understood. Accordingly, in the present study, the role of protein kinase A (PKA)/cAMP response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling in PM2.5-induced neurodevelopmental damage was investigated using primary cultured hippocampal neurons. When hippocampal neurons cultured for 3 days in vitro (DIV3) were exposed to PM2.5 for 24 h and 96 h, neuronal viability decreased by 18.8% and 32.7% respectively, percentage of TUNEL-positive neurons increased by 78.5% and 64.0% separately, caspase-9 expression increased, lower postsynaptic density and shorter active zones were observed by transmission electron microscopy, expression of synapse-related proteins including postsynaptic density-95 (PSD95), growth associated protein-43 (GAP43), and synaptophysin (SYP) were decreased, and the phosphorylation levels of PKA, CREB, and BDNF expression also decreased. However, the PM2.5-induced neuronal damage could be ameliorated or aggravated to varying degrees by up- or down-regulation of the PKA/CREB/BDNF signaling pathway, respectively. Our results indicate that PM2.5 exposure exerts neurodevelopmental toxicity as indicated by lower viability, apoptosis, and synaptic damage in primary cultured hippocampal neurons, and that the PKA/CREB/BDNF pathways could play a vital role in PM2.5-mediated neurodevelopmental toxicity.


Asunto(s)
Neuronas/efectos de los fármacos , Material Particulado/toxicidad , Animales , Apoptosis , Trastorno del Espectro Autista/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Regulación hacia Abajo , Hipocampo/metabolismo , Masculino , Neuronas/metabolismo , Material Particulado/metabolismo , Fosforilación , Ratas , Transducción de Señal , Sinapsis
10.
Nutr Metab Cardiovasc Dis ; 31(1): 333-343, 2021 01 04.
Artículo en Inglés | MEDLINE | ID: mdl-33500109

RESUMEN

BACKGROUND AND AIMS: Diabetes is one of the most important risk factors and comorbidities of ischemic stroke. Endoplasmic reticulum stress (ERS) is considered to be the major injury mechanism of ischemic stroke with diabetes. Studies have found that incretin can inhibit ERS in ischemia-reperfusion injury of the liver and heart. We aimed to explore the effects of GLP-1/GIP double agonist DA3-CH and GLP-1 single agonist liraglutide on ERS and apoptosis in diabetic rats with cerebral ischemia-reperfusion injury. METHODS AND RESULTS: 72 Sprague-Dawley (SD) male rats were randomly divided into 4 groups: ① blank group (Sham group, n = 18); model group (Saline group, n = 18); DA3 treatment group (DA3 group, n = 18); liraglutide treatment group (Lir group, n = 18). The Sham group was not given any treatment and was only raised in the same environment as the other groups. The remaining 3 groups used STZ-induced diabetes models. After the successful membrane formation of diabetes, DA3-CH and liraglutide (10 mmol/kg, once-daily for 14 days) were injected intraperitoneally. Thereafter, rats were subjected to middle cerebral artery occlusion followed by 24-h reperfusion. Animals were evaluated for neurologic deficit score, infarct volume, and biomarker analyses of the brain after ischemia. The DA3-CH-treated and liraglutide-treated groups showed significantly reduced scores of neurological dysfunction and cerebral infarction size, and reduced the expression of ERS markers GRP78, CHOP and Caspase-12, and the expression of apoptosis marker bax. Anti-apoptotic markers bcl-2 and neuronal numbers increased significantly. CONCLUSIONS: DA3-CH and liraglutide have obvious neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes, which can reduce the infarct size and the neurological deficit score. Their exert neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes by inhibiting endoplasmic reticulum stress and thereby reducing apoptosis. DA3 is better than liraglutide.


Asunto(s)
Encéfalo/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Hipoglucemiantes/farmacología , Incretinas/farmacología , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Liraglutida/farmacología , Péptidos/farmacología , Daño por Reperfusión/prevención & control , Animales , Apoptosis/efectos de los fármacos , Proteínas Reguladoras de la Apoptosis/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Humanos , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Ratas Sprague-Dawley , Receptores de la Hormona Gastrointestinal/agonistas , Receptores de la Hormona Gastrointestinal/metabolismo , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Transducción de Señal , Estreptozocina
11.
Cell Stem Cell ; 28(2): 331-342.e5, 2021 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-33450186

RESUMEN

ApoE4, a strong genetic risk factor for Alzheimer disease, has been associated with increased risk for severe COVID-19. However, it is unclear whether ApoE4 alters COVID-19 susceptibility or severity, and the role of direct viral infection in brain cells remains obscure. We tested the neurotropism of SARS-CoV2 in human-induced pluripotent stem cell (hiPSC) models and observed low-grade infection of neurons and astrocytes that is boosted in neuron-astrocyte co-cultures and organoids. We then generated isogenic ApoE3/3 and ApoE4/4 hiPSCs and found an increased rate of SARS-CoV-2 infection in ApoE4/4 neurons and astrocytes. ApoE4 astrocytes exhibited enlarged size and elevated nuclear fragmentation upon SARS-CoV-2 infection. Finally, we show that remdesivir treatment inhibits SARS-CoV2 infection of hiPSC neurons and astrocytes. These findings suggest that ApoE4 may play a causal role in COVID-19 severity. Understanding how risk factors impact COVID-19 susceptibility and severity will help us understand the potential long-term effects in different patient populations.


Asunto(s)
Apolipoproteínas E/metabolismo , Encéfalo/patología , Encéfalo/virología , Células Madre Pluripotentes Inducidas/virología , Tropismo/fisiología , Adenosina Monofosfato/análogos & derivados , Adenosina Monofosfato/farmacología , Alanina/análogos & derivados , Alanina/farmacología , Animales , Antivirales/farmacología , Astrocitos/efectos de los fármacos , Astrocitos/patología , Astrocitos/virología , Diferenciación Celular , Chlorocebus aethiops , Humanos , Degeneración Nerviosa/patología , Neuritas/patología , Neuronas/efectos de los fármacos , Neuronas/patología , Neuronas/virología , Organoides/efectos de los fármacos , Organoides/patología , Organoides/virología , Isoformas de Proteínas/metabolismo , Sinapsis/patología , Células Vero
12.
Life Sci ; 270: 119012, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33422543

RESUMEN

AIMS: Memantine is a non-competitive antagonist of glutamatergic NMDA receptor that is mainly used in the treatment of Alzheimer's disease. The excitatory toxicity mediated by glutamate via glutamatergic receptor signals is considered to be one of the mechanisms mediating neuronal injury and cognitive impairment after exposure to a hypoxic environment at a high altitude. Therefore, in this study, we hypothesized that inhibiting glutamate signaling using memantine could alleviate neuronal injury and cognitive impairment in rats exposed to chronic hypoxia. MAIN METHODS: we made animal models in the natural environment of the Qinghai-Tibet Plateau at an altitude of 4300 m, and used animal behavior, morphology, molecular biology and other methods to evaluate the impact of chronic hypoxia exposure on cognitive function and the neuroprotective effect of Memantine. KEY FINDINGS: Our results showed that the expression of NMDA receptors increased, while the expression of AMPA receptors decreased, after 4 weeks of chronic hypoxia exposure. Concomitantly, apoptotic neuronal cell death in the hippocampus and frontal cortex was significantly increased, along with levels of oxidative stress, whereas innate ability to inhibit free radicals decreased. Moreover, after 8 weeks of hypoxia exposure, learning, memory, and space exploration abilities were significantly decreased. Notably, after treatment with memantine, apoptotic neuronal cell death, oxidative stress, and free radical levels decreased, and the cognitive function of the animals improved. SIGNIFICANCE: Present study shows that chronic hypoxia can produce the excitatory toxicity leading to neural injury and cognitive impairment that can be suppressed with memantine treatment by inhibiting excitatory toxicity.


Asunto(s)
Mal de Altura/metabolismo , Disfunción Cognitiva/tratamiento farmacológico , Memantina/farmacología , Altitud , Mal de Altura/tratamiento farmacológico , Enfermedad de Alzheimer/tratamiento farmacológico , Animales , Muerte Celular/efectos de los fármacos , Cognición/efectos de los fármacos , Modelos Animales de Enfermedad , Antagonistas de Aminoácidos Excitadores/farmacología , Ácido Glutámico/metabolismo , Hipocampo/metabolismo , Hipoxia/metabolismo , Masculino , Memantina/metabolismo , Memoria/efectos de los fármacos , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Neurotoxinas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo
13.
Toxicol Lett ; 340: 23-32, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33421551

RESUMEN

Acrylamide (ACR) is a neurotoxin with moderate acute toxicity. Significant level of ACR exists in diet and drinking water. Occupational exposure causes motor function impairment, but the underlying mechanisms remain poorly defined. This study aims to explore whether microtubule-associated protein tau phosphorylation, excessive activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) signaling pathway and BDNF decline are involved in cerebellar neuron lesions and motor dysfunction after subchronic ACR exposure. The present results displayed that ACR caused gait abnormality and hind foot splay in rats. The HE and Nissl staining results revealed that ACR exposure aggravated cerebellar neuron lesions especially in purkinje cell layer. ACR markedly increased tau phosphorylation at Ser262 and Ser396/404 and inhibited the level of phosphorylation of glycogen synthase kinase 3ß (P-GSK3ß) at Ser9. The PERK-eukaryotic initiation factor-2α (eIF2α)-activating transcription factor 4 (ATF4) pathway was activated to promote CHOP expression and then to accelerate neuron lesions. Furthermore, ACR significantly decreased P-CREB at Ser133 and BDNF expression, which might be related to the inhibition of upstream signals from extracellular signal-related kinase (ERK) and protein kinase B (Akt). This work helps to elucidate the underlying mechanisms of ACR-induced neurotoxicity and present a potential target for prevention against the neurotoxicity.


Asunto(s)
Acrilamida/administración & dosificación , Acrilamida/toxicidad , Conducta Animal/efectos de los fármacos , Cerebelo/efectos de los fármacos , Animales , Esquema de Medicación , Regulación de la Expresión Génica/efectos de los fármacos , Glucógeno Sintasa Quinasa 3 beta/genética , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Actividad Motora/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/fisiología , Fosforilación , Ratas , Ratas Sprague-Dawley
14.
Aquat Toxicol ; 231: 105734, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33385846

RESUMEN

Several studies have suggested eugenol as a suitable anaesthetic for fish. However, it has also been regarded as a toxic and aversive substance to several aquatic organisms, including fish. This study sought to assess the eugenol-induced behavioural alterations and its seizurogenic potential to fish. Moreover, a distinctive methodology for an in vivo evaluation of the brain activity was also presented. Prior to the evaluation of eugenol-induced responses, fish were exposed to pentylenetetrazole (PTZ), to characterize any seizure-like patterns. Antagonizing responses to PTZ were assessed in fish receiving diazepam (BDZ) and subsequently exposed to PTZ. Tambaqui fish juveniles, Colossoma macropomum (15.8 ± 2.8 g) were used as models and assayed as follows: (i) fish exposed to PTZ (15 mM) and (ii) fish receiving a dose of BDZ (10 mg Kg-1) and later exposed to PTZ (15 mM) (BDZ-PTZ group). Thereafter, fish were evaluated throughout (iii) eugenol exposure at 65 µL L-1 (ethanolic solution) and recovery. Control fish and a vehicle control group (ethanol at 585 µL L-1) were also established. PTZ baths elicited body immobilization preceded by hyperactivity in a stereotyped seizure-like behaviour with increased EEG wave amplitude and frequency. PTZ effects in the brain were attenuated by a pre-administration of BDZ. Upon eugenol exposure, tambaqui had an intense neuronal excitability, showing a clonus-like seizure behaviour, also corroborated by the EEG patterns, which were consistent with a seizure-like response. Responses of eugenol-exposed fish resembled those of the PZT-exposed animals, with epileptiform discharges. EMG was in line with the EEG modulation, showing increased tracing oscillations and higher mean amplitudes in PTZ-exposed fish whereas in BDZ-PTZ group muscle contraction was less frequent and powerful. Fish exposed to eugenol showed initially some muscle activity followed by a loss of muscle tonus over time. In summary, our results showed that upon eugenol exposure, although a time-dependent body immobilization was attained, fish presented an intense neuronal excitability comparable to that evoked by PTZ. Eugenol failed to promote depression of the CNS and therefore may be not suitable to be used for general anaesthesia of C. macropomum. As eugenol could be implicated in seizurogenesis and be potentially toxic to the fish brain, protocols suggesting the broad use of eugenol for short-term anaesthesia or euthanasia of fish should be carefully revised, as it raises important concerns in terms of ethics and fish welfare.


Asunto(s)
Characiformes/fisiología , Eugenol/toxicidad , Inmovilización , Neuronas/patología , Animales , Conducta Animal/efectos de los fármacos , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Electrodos , Electroencefalografía , Electromiografía , Fenómenos Electrofisiológicos , Masculino , Músculos/efectos de los fármacos , Neuronas/efectos de los fármacos , Pentilenotetrazol/toxicidad , Contaminantes Químicos del Agua/toxicidad
15.
Methods Mol Biol ; 2240: 207-230, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33423236

RESUMEN

Depletion of oxygen (O2) levels and reduction in the ATP synthesis (or even its complete blockage) are important characteristics of mitochondrial dysfunction; features that are often correlated with neurodegeneration. The measurement of oxygen consumption rate (OCR) is thus essential to evaluate cellular metabolism, survival, and neuroprotective strategies. In the present chapter, we describe the oxygen consumption assay using a Clark-type oxygen electrode in different types of samples named cells suspension (from primary and established cell culture), brain slices (ex vivo), and fresh brain tissues. In addition, we demonstrate herein how the program Oxygraph can be used in order to analyze the data and different approaches to normalize it.


Asunto(s)
Adenosina Trifosfato/metabolismo , Bioensayo , Encéfalo/metabolismo , Mitocondrias/metabolismo , Neuronas/metabolismo , Fosforilación Oxidativa , Consumo de Oxígeno , Animales , Encéfalo/efectos de los fármacos , Línea Celular , Humanos , Técnicas In Vitro , Mitocondrias/efectos de los fármacos , Neuronas/efectos de los fármacos , Fosforilación Oxidativa/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Cultivo Primario de Células , Ratas , Factores de Tiempo
16.
Psychopharmacology (Berl) ; 238(4): 1121-1131, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33454843

RESUMEN

RATIONALE: Cannabinoid type 1 receptors (CB1Rs) are widely expressed within the brain's reward circuits and are implicated in regulating drug induced behavioral adaptations. Understanding how CB1R signaling in discrete circuits and cell types contributes to drug-related behavior provides further insight into the pathology of substance use disorders. OBJECTIVE AND METHODS: We sought to determine how cell type-specific expression of CB1Rs within striatal circuits contributes to cocaine-induced behavioral plasticity, hypothesizing that CB1R function in distinct striatal neuron populations would differentially impact behavioral outcomes. We crossed conditional Cnr1fl/fl mice and striatal output pathway cre lines (Drd1a -cre; D1, Adora2a -cre; A2a) to generate cell type-specific CB1R knockout mice and assessed their performance in cocaine locomotor and associative behavioral assays. RESULTS: Both knockout lines retained typical locomotor activity at baseline. D1-Cre x Cnr1fl/fl mice did not display hyperlocomotion in response to acute cocaine dosing, and both knockout lines exhibited blunted locomotor activity across repeated cocaine doses. A2a-cre Cnr1fl/fl, mice did not express a preference for cocaine paired environments in a two-choice place preference task. CONCLUSIONS: This study aids in mapping CB1R-dependent cocaine-induced behavioral adaptations onto distinct striatal neuron subtypes. A reduction of cocaine-induced locomotor activation in the D1- and A2a-Cnr1 knockout mice supports a role for CB1R function in the motor circuit. Furthermore, a lack of preference for cocaine-associated context in A2a-Cnr1 mice suggests that CB1Rs on A2a-neuron inhibitory terminals are necessary for either reward perception, memory consolidation, or recall. These results direct future investigations into CB1R-dependent adaptations underlying the development and persistence of substance use disorders.


Asunto(s)
Trastornos Relacionados con Cocaína/psicología , Ambiente , Neuronas/efectos de los fármacos , Receptor de Adenosina A2A/efectos de los fármacos , Receptor Cannabinoide CB1/efectos de los fármacos , Receptor Cannabinoide CB1/metabolismo , Animales , Condicionamiento Operante/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Masculino , Ratones , Ratones Noqueados , Actividad Motora/efectos de los fármacos , Receptor de Adenosina A2A/genética , Receptor Cannabinoide CB1/genética , Recompensa
17.
Br J Anaesth ; 126(3): 674-683, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33388140

RESUMEN

BACKGROUND: Multiple cognitive and psychiatric disorders are associated with an increased tonic inhibitory conductance that is generated by α5 subunit-containing γ-aminobutyric acid type A (α5 GABAA) receptors. Negative allosteric modulators that inhibit α5 GABAA receptors (α5-NAMs) are being developed as treatments for these disorders. The effects of α5-NAMs have been studied on recombinant GABAA receptors expressed in non-neuronal cells; however, no study has compared drug effects on the tonic conductance generated by native GABAA receptors in neurones, which was the goal of this study. METHODS: The effects of five α5-NAMs (basmisanil, Ono-160, L-655,708, α5IA, and MRK-016) on tonic current evoked by a low concentration of GABA were studied using whole-cell recordings in cultured mouse hippocampal neurones. Drug effects on current evoked by a saturating concentration of GABA and on miniature inhibitory postsynaptic currents (mIPSCs) were also examined. RESULTS: The α5-NAMs caused a concentration-dependent decrease in tonic current. The potencies varied as the inhibitory concentration for 50% inhibition (IC50) of basmisanil (127 nM) was significantly higher than those of the other compounds (0.4-0.8 nM). In contrast, the maximal efficacies of the drugs were similar (35.5-51.3% inhibition). The α5-NAMs did not modify current evoked by a saturating GABA concentration or mIPSCs. CONCLUSIONS: Basmisanil was markedly less potent than the other α5-NAMs, an unexpected result based on studies of recombinant α5 GABAA receptors. Studying the effects of α5 GABAA receptor-selective drugs on the tonic inhibitory current in neurones could inform the selection of compounds for future clinical trials.


Asunto(s)
Disfunción Cognitiva/tratamiento farmacológico , Antagonistas de Receptores de GABA-A/farmacología , Hipocampo/efectos de los fármacos , Potenciales Postsinápticos Inhibidores/efectos de los fármacos , Neuronas/efectos de los fármacos , Receptores de GABA-A/metabolismo , Regulación Alostérica , Animales , Células Cultivadas , Cognición/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Hipocampo/metabolismo , Ratones , Neuronas/metabolismo , Técnicas de Placa-Clamp
18.
Anesthesiology ; 134(3): 405-420, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33411921

RESUMEN

BACKGROUND: Cardiac sympathoexcitation leads to ventricular arrhythmias. Spinal anesthesia modulates sympathetic output and can be cardioprotective. However, its effect on the cardio-spinal reflexes and network interactions in the dorsal horn cardiac afferent neurons and the intermediolateral nucleus sympathetic neurons that regulate sympathetic output is not known. The authors hypothesize that spinal bupivacaine reduces cardiac neuronal firing and network interactions in the dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus that produce sympathoexcitation during myocardial ischemia, attenuating ventricular arrhythmogenesis. METHODS: Extracellular neuronal signals from the dorsal horn and intermediolateral nucleus neurons were simultaneously recorded in Yorkshire pigs (n = 9) using a 64-channel high-density penetrating microarray electrode inserted at the T2 spinal cord. Dorsal horn and intermediolateral nucleus neural interactions and known markers of cardiac arrhythmogenesis were evaluated during myocardial ischemia and cardiac load-dependent perturbations with intrathecal bupivacaine. RESULTS: Cardiac spinal neurons were identified based on their response to myocardial ischemia and cardiac load-dependent perturbations. Spinal bupivacaine did not change the basal activity of cardiac neurons in the dorsal horn or intermediolateral nucleus. After bupivacaine administration, the percentage of cardiac neurons that increased their activity in response to myocardial ischemia was decreased. Myocardial ischemia and cardiac load-dependent stress increased the short-term interactions between the dorsal horn and dorsal horn (324 to 931 correlated pairs out of 1,189 pairs, P < 0.0001), and dorsal horn and intermediolateral nucleus neurons (11 to 69 correlated pairs out of 1,135 pairs, P < 0.0001). Bupivacaine reduced this network response and augmentation in the interactions between dorsal horn-dorsal horn (931 to 38 correlated pairs out of 1,189 pairs, P < 0.0001) and intermediolateral nucleus-dorsal horn neurons (69 to 1 correlated pairs out of 1,135 pairs, P < 0.0001). Spinal bupivacaine reduced shortening of ventricular activation recovery interval and dispersion of repolarization, with decreased ventricular arrhythmogenesis during acute ischemia. CONCLUSIONS: Spinal anesthesia reduces network interactions between dorsal horn-dorsal horn and dorsal horn-intermediolateral nucleus cardiac neurons in the spinal cord during myocardial ischemia. Blocking short-term coordination between local afferent-efferent cardiac neurons in the spinal cord contributes to a decrease in cardiac sympathoexcitation and reduction of ventricular arrhythmogenesis.


Asunto(s)
Anestesia Raquidea/métodos , Arritmias Cardíacas/etiología , Arritmias Cardíacas/prevención & control , Isquemia Miocárdica/complicaciones , Neuronas/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Potenciales de Acción/efectos de los fármacos , Animales , Modelos Animales de Enfermedad , Femenino , Masculino , Porcinos
19.
J Med Chem ; 64(2): 1073-1102, 2021 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-33411523

RESUMEN

Studies in tau and Aß plaque transgenic mouse models demonstrated that brain-penetrant microtubule (MT)-stabilizing compounds, including the 1,2,4-triazolo[1,5-a]pyrimidines, hold promise as candidate treatments for Alzheimer's disease and related neurodegenerative tauopathies. Triazolopyrimidines have already been investigated as anticancer agents; however, the antimitotic activity of these compounds does not always correlate with stabilization of MTs in cells. Indeed, previous studies from our laboratories identified a critical role for the fragment linked at C6 in determining whether triazolopyrimidines promote MT stabilization or, conversely, disrupt MT integrity in cells. To further elucidate the structure-activity relationship (SAR) and to identify potentially improved MT-stabilizing candidates for neurodegenerative disease, a comprehensive set of 68 triazolopyrimidine congeners bearing structural modifications at C6 and/or C7 was designed, synthesized, and evaluated. These studies expand upon prior understanding of triazolopyrimidine SAR and enabled the identification of novel analogues that, relative to the existing lead, exhibit improved physicochemical properties, MT-stabilizing activity, and pharmacokinetics.


Asunto(s)
Microtúbulos/efectos de los fármacos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Pirimidinas/química , Pirimidinas/farmacología , Tauopatías/tratamiento farmacológico , Triazoles/química , Triazoles/farmacología , Animales , Encéfalo/metabolismo , Línea Celular , Células Cultivadas , Simulación por Computador , Humanos , Ratones , Ratones Transgénicos , Modelos Moleculares , Simulación del Acoplamiento Molecular , Neuronas/efectos de los fármacos , Ratas , Relación Estructura-Actividad
20.
Analyst ; 146(2): 454-462, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33491017

RESUMEN

Neuronal cell microengineering involving micropatterning and polydimethylsiloxane (PDMS) microfluidics enables promising advances in microscale neuron control. However, a facile methodology for the precise and effective manipulation of neurons on a cell-repellent PDMS substrate remains challenging. Herein, a simple and straightforward strategy for neuronal cell patterning and neuronal network construction on PDMS based on microfluidics-assisted modification of functionalized Pluronic is described. The cell patterning process simply involves a one-step microfluidic modification and routine in vitro culture. It is demonstrated that multiple types of neuronal cell arrangements with various spatial profiles can be conveniently produced using this patterning tool. The precise control of neuronal cells with high patterning fidelity up to single cell resolution, as well as high adhesion and differentiation, is achieved too. Furthermore, neuronal network construction using the respective cell population and single cell patterning prove to be applicable. This achievement provides a convenient and feasible methodology for engineering neuronal cells on PDMS substrates, which will be useful for applications in many neuron-related microscale analytical research fields, including cell engineering, neurobiology, neuropharmacology, and neuronal sensing.


Asunto(s)
Ingeniería Celular/instrumentación , Dimetilpolisiloxanos/química , Dimetilpolisiloxanos/farmacología , Dispositivos Laboratorio en un Chip , Red Nerviosa/citología , Neuronas/citología , Poloxámero/química , Animales , Axones/efectos de los fármacos , Axones/metabolismo , Dendritas/efectos de los fármacos , Dendritas/metabolismo , Ratones , Ratones Endogámicos C57BL , Neuronas/efectos de los fármacos , Imagen Óptica
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