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BACKGROUND: Cannabidiol (CBD) is one of the main cannabinoids present in Cannabis sativa female flowers. Previous investigation has already provided insights into the CBD molecular mechanism; however, there is no transcriptome data for CBD effects on hippocampal subfields. Here, we investigate transcriptomic changes in dorsal and ventral CA1 of adult mice hippocampus after 100 mg/kg of CBD administration (i.p.) for one or seven consecutive days. METHODS: C57BL/6JUnib mice were treated with either vehicle or CBD for 1 or 7 days. The collected brains were sectioned, and the hippocampal sub-regions were laser microdissected for RNA-Seq analysis. RESULTS: The transcriptome analysis following 7 days of CBD administration indicates the differential expression of 1559 genes in dCA1 and 2924 genes in vCA1. Furthermore, GO/KEGG analysis identified 88 significantly enriched biological process and 26 significantly enriched pathways for dCBD7, whereas vCBD7 revealed 128 enriched BPs and 24 pathways. CONCLUSION: This dataset indicates a widespread decrease of electron transport chain and ribosome biogenesis transcripts in CA1, while chromatin modifications and synapse organization transcripts were increased following CBD administration for 7 days.
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Cannabidiol , Hipocampo , Ratones Endogámicos C57BL , Mitocondrias , Ribosomas , Sinapsis , Cannabidiol/farmacología , Animales , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo , Ratones , Ribosomas/efectos de los fármacos , Ribosomas/metabolismo , Ribosomas/genética , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/genética , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Transcriptoma/efectos de los fármacos , Masculino , Cromatina/efectos de los fármacos , Cromatina/metabolismo , Cromatina/genética , Región CA1 Hipocampal/efectos de los fármacos , Región CA1 Hipocampal/metabolismo , Perfilación de la Expresión Génica/métodosRESUMEN
Focal cortical dysplasia (FCD) is a brain malformation that causes medically refractory epilepsy. FCD is classified into three categories based on structural and cellular abnormalities, with FCD type II being the most common and characterized by disrupted organization of the cortex and abnormal neuronal development. In this study, we employed cell-type deconvolution and single-cell signatures to analyze bulk RNA-seq from multiple transcriptomic studies, aiming to characterize the cellular composition of brain lesions in patients with FCD IIa and IIb subtypes. Our deconvolution analyses revealed specific cellular changes in FCD IIb, including neuronal loss and an increase in reactive astrocytes (astrogliosis) when compared to FCD IIa. Astrogliosis in FCD IIb was further supported by a gene signature analysis and histologically confirmed by glial fibrillary acidic protein (GFAP) immunostaining. Overall, our findings demonstrate that FCD II subtypes exhibit differential neuronal and glial compositions, with astrogliosis emerging as a hallmark of FCD IIb. These observations, validated in independent patient cohorts and confirmed using immunohistochemistry, offer novel insights into the involvement of glial cells in FCD type II pathophysiology and may contribute to the development of targeted therapies for this condition.
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Displasia Cortical Focal , Malformaciones del Desarrollo Cortical de Grupo I , Humanos , Gliosis , NeuroglíaRESUMEN
The hippocampus comprises several neuronal populations such as CA1, CA2, CA3, and the dentate gyrus (DG), which present different neuronal origins, morphologies, and molecular mechanisms. Laser capture microdissection (LCM) allows selectively collecting samples from target regions and eliminating unwanted cells to obtain more specific results. LCM of hippocampus neuronal populations coupled with RNA-seq analysis has the potential to allow the exploration of the molecular machinery unique to each of these subfields. Previous RNA-seq investigation has already provided a molecular blueprint of the hippocampus, however, there is no RNA-seq data specific for each of the rat hippocampal regions. Serial tissue sections covering the hippocampus were produced from frozen brains of adult male Wistar rats, and the hippocampal subfields CA1, CA2, CA3, and DG were identified and isolated by LCM. We found evident segregation of the transcriptomic profile from different regions of the hippocampus and the expression of known, as well as novel, specific marker genes for each region. Gene ontology enrichment analysis of CA1 subfield indicates an enrichment of actin regulation and postsynaptic membrane AMPA receptors genes indispensable for long-term potentiation. CA2 and CA3 transcripts were found associated with the increased metabolic processes. DG expression was enriched for ribosome and spliceosome, both required for protein synthesis and maintenance of cell life. The present findings contribute to a deeper understanding of the differences in the molecular machinery expressed by the rat hippocampal neuronal populations, further exploring underlying mechanisms responsible for each subflied specific functions.
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OBJECTIVES: We compared the proteomic signatures of the hippocampal lesion induced in three different animal models of mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS): the systemic pilocarpine model (PILO), the intracerebroventricular kainic acid model (KA), and the perforant pathway stimulation model (PPS). METHODS: We used shotgun proteomics to analyze the proteomes and find enriched biological pathways of the dorsal and ventral dentate gyrus (DG) isolated from the hippocampi of the three animal models. We also compared the proteomes obtained in the animal models to that from the DG of patients with pharmacoresistant MTLE+HS. RESULTS: We found that each animal model presents specific profiles of proteomic changes. The PILO model showed responses predominantly related to neuronal excitatory imbalance. The KA model revealed alterations mainly in synaptic activity. The PPS model displayed abnormalities in metabolism and oxidative stress. We also identified common biological pathways enriched in all three models, such as inflammation and immune response, which were also observed in tissue from patients. However, none of the models could recapitulate the profile of molecular changes observed in tissue from patients. SIGNIFICANCE: Our results indicate that each model has its own set of biological responses leading to epilepsy. Thus, it seems that only using a combination of the three models may one replicate more closely the mechanisms underlying MTLE+HS as seen in patients.
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Epilepsia del Lóbulo Temporal , Epilepsia , Animales , Benchmarking , Modelos Animales de Enfermedad , Epilepsia/patología , Epilepsia del Lóbulo Temporal/patología , Humanos , Proteoma , Proteómica , EsclerosisRESUMEN
A SARS-CoV-2 B.1.1.7 variant of concern (VOC) has been associated with increased transmissibility, hospitalization, and mortality. This study aimed to explore the factors associated with B.1.1.7 VOC infection in the context of vaccination. On March 2021, we detected SARS-CoV-2 RNA in nasopharyngeal samples from 14 of 22 individuals vaccinated with a single-dose of ChAdOx1 (outbreak A, n = 26), and 22 of 42 of individuals with two doses of the CoronaVac vaccine (outbreak B, n = 52) for breakthrough infection rates for ChAdOx1 of 63.6% and 52.4% for CoronaVac. The outbreaks were caused by two independent clusters of the B.1.1.7 VOC. The serum of PCR-positive symptomatic SARS-CoV-2-infected individuals had ~1.8-3.4-fold more neutralizing capacity against B.1.1.7 compared to the serum of asymptomatic individuals. These data based on exploratory analysis suggest that the B.1.1.7 variant can infect individuals partially immunized with a single dose of an adenovirus-vectored vaccine or fully immunized with two doses of an inactivated vaccine, although the vaccines were able to reduce the risk of severe disease and death caused by this VOC, even in the elderly.
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Vacunas contra la COVID-19 , COVID-19/inmunología , COVID-19/virología , SARS-CoV-2/clasificación , SARS-CoV-2/genética , Vacunación , Adenoviridae , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Neutralizantes/inmunología , Brasil/epidemiología , COVID-19/prevención & control , Prueba Serológica para COVID-19 , Estudios de Cohortes , Brotes de Enfermedades/estadística & datos numéricos , Femenino , Vectores Genéticos , Humanos , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , ARN Viral , Vacunas de Productos Inactivados , Secuenciación Completa del Genoma , Adulto JovenRESUMEN
In this cross-sectional study, we investigate the presence of Severe Acute Respiratory Syndrome Coronavirus 2 Ribonucleic Acid (SARS-CoV-2 RNA) in the tears of hospitalized COVID-19 patients. After laboratory confirmation of SARS-CoV-2 infection by reverse transcription polymerase chain reaction (RT-PCR) analysis, tear samples from both eyes of each patient were collected using conjunctival swab for RT-PCR. Detailed demographic profile, systemic and ocular symptoms, comorbidities, clinical, ancillary, and ocular manifestations were evaluated. Of the 83 patients enrolled in the study, 7 (8.43%) had SARS-CoV-2 RNA detected in the tear samples. Neutrophils' count, C-reactive protein, and D-dimer were higher in patients with SARS-CoV-2 detected in tears than in patients without virus in ocular surface samples. One patient with SARS-CoV-2 in tears showed mild ocular eyelid edema, hyperemia, and chemosis. No relevant ocular manifestations were detected in the other patients. Although the levels of viral RNA on ocular surface samples were low for most patients (5/7), with positivity only for gene N and CT higher than 30, two patients were positive for all viral targets tested (N, E, and RpRd), with viral load near 1 × 105 ePFU/mL, indicating that the ocular transmission of SARS-CoV-2 is a possibility that needs to be considered, especially in the hospital environment. Further studies need to be conducted to demonstrate whether infective viral particles could be isolated from tears.
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COVID-19/virología , Infecciones Virales del Ojo/virología , Ojo/virología , SARS-CoV-2/patogenicidad , Adulto , Anciano , Brasil , COVID-19/complicaciones , COVID-19/patología , Prueba de Ácido Nucleico para COVID-19/estadística & datos numéricos , Infecciones Virales del Ojo/epidemiología , Infecciones Virales del Ojo/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2/genética , Lágrimas/virología , Carga ViralRESUMEN
The evolution of obligate ectoparasitism in blowflies (Diptera: Calliphoridae) has intrigued scientists for over a century, and surprisingly, the genetics underlying this lifestyle remain largely unknown. Blowflies use odors to locate food and oviposition sites; therefore, olfaction might have played a central role in niche specialization within the group. In insects, the coreceptor Orco is a required partner for all odorant receptors (ORs), a major gene family involved in olfactory-evoked behaviors. Hence, we characterized the Orco gene in the New World screwworm, Cochliomyia hominivorax, a blowfly that is an obligate ectoparasite of warm-blooded animals. In contrast, most of the closely related blowflies are scavengers that lay their eggs on dead animals. We show that the screwworm Orco orthologue (ChomOrco) is highly conserved within Diptera, showing signals of strong purifying selection. Expression of ChomOrco is broadly detectable in chemosensory appendages, and is related to morphological, developmental, and behavioral aspects of the screwworm biology. We used CRISPR/Cas9 to disrupt ChomOrco and evaluate the consequences of losing the OR function on screwworm behavior. In two-choice assays, Orco mutants displayed an impaired response to floral-like and animal host-associated odors, suggesting that OR-mediated olfaction is involved in foraging and host-seeking behaviors in C. hominivorax. These results broaden our understanding of the chemoreception basis of niche occupancy by blowflies.
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Dípteros/fisiología , Conducta Alimentaria , Conducta de Búsqueda de Hospedador , Proteínas de Insectos/metabolismo , Receptores Odorantes/metabolismo , Animales , Dípteros/metabolismo , Proteínas de Insectos/genética , Mutación , Filogenia , Receptores Odorantes/genética , OlfatoRESUMEN
We documented 4 cases of severe acute respiratory syndrome coronavirus 2 reinfection by non-variant of concern strains among healthcare workers in Campinas, Brazil. We isolated infectious particles from nasopharyngeal secretions during both infection episodes. Improved and continued protection measures are necessary to mitigate the risk for reinfection among healthcare workers.
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COVID-19/diagnóstico , Personal de Salud , Reinfección/diagnóstico , Reinfección/virología , SARS-CoV-2/aislamiento & purificación , Esparcimiento de Virus , Adulto , Brasil/epidemiología , COVID-19/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Reinfección/terapiaRESUMEN
Mesial temporal lobe epilepsy (MTLE) is a chronic neurological disorder characterized by the occurrence of seizures, and histopathological abnormalities in the mesial temporal lobe structures, mainly hippocampal sclerosis (HS). We used a multi-omics approach to determine the profile of transcript and protein expression in the dorsal and ventral hippocampal dentate gyrus (DG) and Cornu Ammonis 3 (CA3) in an animal model of MTLE induced by pilocarpine. We performed label-free proteomics and RNAseq from laser-microdissected tissue isolated from pilocarpine-induced Wistar rats. We divided the DG and CA3 into dorsal and ventral areas and analyzed them separately. We performed a data integration analysis and evaluated enriched signaling pathways, as well as the integrated networks generated based on the gene ontology processes. Our results indicate differences in the transcriptomic and proteomic profiles among the DG and the CA3 subfields of the hippocampus. Moreover, our data suggest that epileptogenesis is enhanced in the CA3 region when compared to the DG, with most abnormalities in transcript and protein levels occurring in the CA3. Furthermore, our results show that the epileptogenesis in the pilocarpine model involves predominantly abnormal regulation of excitatory neuronal mechanisms mediated by N-methyl D-aspartate (NMDA) receptors, changes in the serotonin signaling, and neuronal activity controlled by calcium/calmodulin-dependent protein kinase (CaMK) regulation and leucine-rich repeat kinase 2 (LRRK2)/WNT signaling pathways.
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Epilepsia del Lóbulo Temporal , Animales , Epilepsia del Lóbulo Temporal/patología , Hipocampo/metabolismo , Pilocarpina/toxicidad , Proteómica , Ratas , Ratas WistarRESUMEN
COVID-19 can result in severe lung injury. It remained to be determined why diabetic individuals with uncontrolled glucose levels are more prone to develop the severe form of COVID-19. The molecular mechanism underlying SARS-CoV-2 infection and what determines the onset of the cytokine storm found in severe COVID-19 patients are unknown. Monocytes and macrophages are the most enriched immune cell types in the lungs of COVID-19 patients and appear to have a central role in the pathogenicity of the disease. These cells adapt their metabolism upon infection and become highly glycolytic, which facilitates SARS-CoV-2 replication. The infection triggers mitochondrial ROS production, which induces stabilization of hypoxia-inducible factor-1α (HIF-1α) and consequently promotes glycolysis. HIF-1α-induced changes in monocyte metabolism by SARS-CoV-2 infection directly inhibit T cell response and reduce epithelial cell survival. Targeting HIF-1É may have great therapeutic potential for the development of novel drugs to treat COVID-19.
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Betacoronavirus/fisiología , Glucemia/metabolismo , Infecciones por Coronavirus/complicaciones , Complicaciones de la Diabetes/complicaciones , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Monocitos/metabolismo , Neumonía Viral/complicaciones , Adulto , COVID-19 , Línea Celular , Infecciones por Coronavirus/metabolismo , Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus/metabolismo , Femenino , Glucólisis , Humanos , Inflamación/complicaciones , Inflamación/metabolismo , Masculino , Persona de Mediana Edad , Monocitos/virología , Pandemias , Neumonía Viral/metabolismo , Especies Reactivas de Oxígeno/metabolismo , SARS-CoV-2 , Transducción de SeñalRESUMEN
Mesial temporal lobe epilepsy (MTLE) is a chronic neurological disorder affecting almost 40% of adult patients with epilepsy. Hippocampal sclerosis (HS) is a common histopathological abnormality found in patients with MTLE. HS is characterised by extensive neuronal loss in different hippocampus sub-regions. In this study, we used laser microdissection-based microproteomics to determine the protein abundances in different regions and layers of the hippocampus dentate gyrus (DG) in an electric stimulation rodent model which displays classical HS damage similar to that found in patients with MTLE. Our results indicate that there are differences in the proteomic profiles of different layers (granule cell and molecular), as well as different regions, of the DG (ventral and dorsal). We have identified new signalling pathways and proteins present in specific layers and regions of the DG, such as PARK7, RACK1, and connexin 31/gap junction. We also found two major signalling pathways that are common to all layers and regions: inflammation and energy metabolism. Finally, our results highlight the utility of high-throughput microproteomics and spatial-limited isolation of tissues in the study of complex disorders to fully appreciate the large biological heterogeneity present in different cell populations within the central nervous system.
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Conexinas/metabolismo , Epilepsia del Lóbulo Temporal/metabolismo , Hipocampo/metabolismo , Proteína Desglicasa DJ-1/metabolismo , Proteómica/métodos , Receptores de Cinasa C Activada/metabolismo , Animales , Modelos Animales de Enfermedad , Epilepsia del Lóbulo Temporal/etiología , Regulación de la Expresión Génica , Humanos , Captura por Microdisección con Láser , Especificidad de Órganos , Mapas de Interacción de Proteínas , Ratas , Transducción de SeñalRESUMEN
Microdissection techniques are very important for anatomical and functional studies focused on neuroscience, where it is often necessary microdissect specific brain areas to perform molecular or anatomical analyses. The parafilm®-assisted microdissection (PAM) was previously described and involves the microdissection of tissue sections mounted on parafilm-covered glass slides. In this work, we describe the use of the PAM method to microdissect rodent nucleus accumbens (NAc). (1) We first describe the best way to perform the mouse euthanasia and how to remove the brain. (2) Next, we describe how to prepare the slides with parafilm® that will be used to receive the brain slices. (3) Following, we describe how to handle the brain in the cryostat, how to align the hemispheres and how to identify the NAc antero-posterior limits. (4) We also describe how to perform the staining and dehydration of the slices, a critical step to facilitate the microdissection and preserve macromolecules. (5) In the final step, we describe how to identify the dorso-ventral and latero-medial limits of the NAc and, finally, how to perform the manual microdissection of the area. This is a low-cost technique that allows the researcher to specifically microdissect any brain region, from which intact RNA and proteins can be extracted to perform several molecular analyses (e.g., real-time PCR, Western blot, and RNA-seq).
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OBJECTIVE: Focal cortical dysplasias (FCDs) are an important cause of drug-resistant epilepsy. In this work, we aimed to investigate whether abnormal gene regulation, mediated by microRNA, could be involved in FCD type II. METHODS: We used total RNA from the brain tissue of 16 patients with FCD type II and 28 controls. MicroRNA expression was initially assessed by microarray. Quantitative polymerase chain reaction, in situ hybridization, luciferase reporter assays, and deep sequencing for genes in the mTOR pathway were performed to validate and further explore our initial study. RESULTS: hsa-let-7f (p = 0.039), hsa-miR-31 (p = 0.0078), and hsa-miR34a (p = 0.021) were downregulated in FCD type II, whereas a transcription factor involved in neuronal and glial fate specification, NEUROG2 (p < 0.05), was upregulated. We also found that the RND2 gene, a NEUROG2-target, is upregulated (p < 0.001). In vitro experiments showed that hsa-miR-34a downregulates NEUROG2 by binding to its 5'-untranslated region. Moreover, we observed strong nuclear expression of NEUROG2 in balloon cells and dysmorphic neurons and found that 28.5% of our patients presented brain somatic mutations in genes of the mTOR pathway. INTERPRETATION: Our findings suggest a new molecular mechanism, in which NEUROG2 has a pivotal and central role in the pathogenesis of FCD type II. In this way, we found that the downregulation of hsa-miR-34a leads to upregulation of NEUROG2, and consequently to overexpression of the RND2 gene. These findings indicate that a faulty coupling in neuronal differentiation and migration mechanisms may explain the presence of aberrant cells and complete dyslamination in FCD type II. Ann Neurol 2018;83:623-635.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Epilepsia/metabolismo , Hipoplasia Dérmica Focal/metabolismo , Malformaciones del Desarrollo Cortical/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Adolescente , Adulto , Niño , Preescolar , Epilepsia Refractaria/genética , Epilepsia/tratamiento farmacológico , Epilepsia/genética , Femenino , Hipoplasia Dérmica Focal/genética , Humanos , Lactante , Masculino , Neuronas/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Factores de Transcripción/genética , Adulto Joven , Proteínas de Unión al GTP rho/metabolismoRESUMEN
Epilepsy is misdiagnosed in up to 25% of patients, leading to serious and long-lasting consequences. Recently, circulating microRNAs have emerged as potential biomarkers in a number of clinical scenarios. The purpose of this study was to identify and to validate circulating microRNAs that could be used as biomarkers in the diagnosis of epilepsy. Quantitative real-time PCR was used to measure plasma levels of three candidate microRNAs in two phases of study: an initial discovery phase with 14 patients with mesial temporal lobe epilepsy (MTLE), 13 with focal cortical dysplasia (FCD) and 16 controls; and a validation cohort constituted of an independent cohort of 65 patients with MTLE and 83 controls. We found hsa-miR-134 downregulated in patients with MTLE (p = 0.018) but not in patients with FCD, when compared to controls. Furthermore, hsa-miR-134 expression could be used to discriminate MTLE patients with an area under the curve (AUC) of 0.75. To further assess the robustness of hsa-miR-134 as a biomarker for MTLE, we studied an independent cohort of 65 patients with MTLE, 27 of whom MTLE patients were responsive to pharmacotherapy, and 38 patients were pharmacoresistant and 83 controls. We confirmed that hsa-miR-134 was significantly downregulated in the plasma of patients with MTLE when compared with controls (p < 0.001). In addition, hsa-miR-134 identified patients with MTLE regardless of their response to pharmacotherapy or the presence of MRI signs of hippocampal sclerosis. We revealed that decreased expression of hsa-miR-134 could be a potential non-invasive biomarker to support the diagnosis of patients with MTLE.
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Biomarcadores/sangre , Epilepsia del Lóbulo Temporal/sangre , MicroARNs/sangre , Estudios de Cohortes , Epilepsia del Lóbulo Temporal/genética , Femenino , Humanos , Masculino , Transcripción ReversaRESUMEN
BACKGROUND: Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons. RESULTS: Adult pigeons kept under a skeleton photoperiod were assigned to six different groups. Homogenates of the hippocampus obtained at six different times-of-day were used for NOS analyses. Both iNOS activity and nNOS cytosolic protein concentrations were highest during the subjective light phase and lowest in the subjective dark phase of the circadian period. ANOVA showed significant time differences for iNOS enzymatic activity (p < 0.05) and for nNOS protein content (p < 0.05) in the hippocampus. A significant daily rhythm for both iNOS and nNOS was confirmed by analysis with the Cosinor method (p < 0.05). The present findings indicate that the enzymatic activity of iNOS and content of nNOS protein in the hippocampus of pigeons exhibit a daily rhythm, with acrophase values occurring during the behavioral activity phase. CONCLUSIONS: The data corroborate the reports on circadian variation of NOS in the mammalian hippocampus and can be considered indicative of a dynamic interaction between hippocampus-dependent processes and circadian clock mechanisms.
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Epilepsy, one of the most frequent neurological disorders, represents a group of diseases that have in common the clinical occurrence of seizures. The pathogenesis of different types of epilepsy involves many important biological pathways; some of which have been shown to be regulated by microRNAs (miRNAs). In this paper, we will critically review relevant studies regarding the role of miRNAs in epilepsy. Overall, the most common type of epilepsy in the adult population is temporal lobe epilepsy (TLE), and the form associated with mesial temporal sclerosis (MTS), called mesial TLE, is particularly relevant due to the high frequency of resistance to clinical treatment. There are several target studies, as well few genome-wide miRNA expression profiling studies reporting abnormal miRNA expression in tissue with MTS, both in patients and in animal models. Overall, these studies show a fine correlation between miRNA regulation/dysregulation and inflammation, seizure-induced neuronal death and other relevant biological pathways. Furthermore, expression of many miRNAs is dynamically regulated during neurogenesis and its dysregulation may play a role in the process of cerebral corticogenesis leading to malformations of cortical development (MCD), which represent one of the major causes of drug-resistant epilepsy. In addition, there are reports of miRNAs involved in cell proliferation, fate specification, and neuronal maturation and these processes are tightly linked to the pathogenesis of MCD. Large-scale analyzes of miRNA expression in animal models with induced status epilepticus have demonstrated changes in a selected group of miRNAs thought to be involved in the regulation of cell death, synaptic reorganization, neuroinflammation, and neural excitability. In addition, knocking-down specific miRNAs in these animals have demonstrated that this may consist in a promising therapeutic intervention.
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Every year traumatic peripheral nerve injuries (TPNI) result in considerable physical disability across the world; the mechanisms of plasticity and reorganization of spinal cord circuits following such injuries are complex and not completely understood. A comparative proteome analysis between neonatal rats submitted to peripheral lesion and controls was performed; a number of differentially expressed proteins involved in oxidative stress response, energy metabolism and cytoskeleton rearrangement were revealed, which may support future studies to help in the understanding and a posteriori the treatment of TPNI.
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Enfermedades del Sistema Nervioso Periférico/metabolismo , Enfermedades del Sistema Nervioso Periférico/patología , Proteoma/metabolismo , Médula Espinal/metabolismo , Animales , Animales Recién Nacidos , Axotomía/métodos , Electroforesis en Gel Bidimensional/métodos , Vértebras Lumbares , Ratas , Ratas WistarRESUMEN
Ciliary neurotrophic factor (CNTF) regulates the differentiation and survival of a wide spectrum of developing and adult neurons, including motor neuron loss after injury. We recently described a cell-penetrant recombinant human CNTF (rhCNTF) molecule, formed by fusion with the human immunodeficiency virus-1 transactivator of transcription (TAT) protein transduction domain (TAT-CNTF) that, upon subcutaneous administration, retains full neurotrophic activity without cytokine-like side-effects. Although the CNTF receptor is present in hypothalamic nuclei, which are involved in the control of energy, rhCNTF but not TAT-CNTF stimulates signal transducers and activators of transcription 3 phosphorylation in the rat hypothalamus after subcutaneous administration. This could be due limited TAT-CNTF distribution in the hypothalamus and/or altered intracellular signaling by the fusion protein. To explore these possibilities, we examined the effect of intracerebroventricular administration of TAT-CNTF in male adult rats. TAT-CNTF-induced weight loss, although the effect was smaller than that seen with either rhCNTF or leptin (which exerts CNTF-like effects via its receptor). In contrast to rhCNTF and leptin, TAT-CNTF neither induced morphological changes in adipose tissues nor increased uncoupling protein 1 expression in brown adipose tissue, a characteristic feature of rhCNTF and leptin. Acute intracerebroventricular administration of TAT-CNTF induced a less robust phosphorylation of signal transducers and activators of transcription 3 in the hypothalamus, compared with rhCNTF. The data show that fusion of a protein transduction domain may change rhCNTF CNS distribution, while further strengthening the utility of cell-penetrating peptide technology to neurotrophic factor biology beyond the neuroscience field.
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Factor Neurotrófico Ciliar/administración & dosificación , Factor Neurotrófico Ciliar/antagonistas & inhibidores , Productos del Gen tat/metabolismo , Transducción Genética/métodos , Animales , Factor Neurotrófico Ciliar/genética , Factor Neurotrófico Ciliar/metabolismo , Productos del Gen tat/administración & dosificación , Productos del Gen tat/genética , Humanos , Hipotálamo/citología , Hipotálamo/metabolismo , Hipotálamo/fisiología , Inyecciones Intraventriculares , Masculino , Neuronas/metabolismo , Neuronas/fisiología , Estructura Terciaria de Proteína/genética , Ratas , Ratas Wistar , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/antagonistas & inhibidores , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal/genética , Transducción de Señal/fisiologíaRESUMEN
Ciliary neurotrophic factor (CNTF) is a multifunctional cytokine that can regulate the survival and differentiation of many types of developing and adult neurons. CNTF prevents the degeneration of motor neurons after axotomy and in mouse mutant progressive motor neuronopathy, which has encouraged trials of CNTF for human motor neuron disease. Given systemically, however, CNTF causes severe side effects, including cachexia and a marked immune response, which has limited its clinical application. The present work describes a novel approach for administering recombinant human CNTF (rhCNTF) while conserving neurotrophic activity and avoiding deleterious side effects. rhCNTF was fused to a protein transduction domain derived from the human immunodeficiency virus-1 TAT (transactivator) protein. The resulting fusion protein (TAT-CNTF) crosses the plasma membrane within minutes and displays a nuclear localization. TAT-CNTF was equipotent to rhCNTF in supporting the survival of cultured chicken embryo dorsal root ganglion neurons. Local or subcutaneous administration of TAT-CNTF, like rhCNTF rescued motor neurons from death in neonatal rats subjected to sciatic nerve transection. In contrast to subcutaneous rhCNTF, which caused a 20-30% decrease in body weight in neonatal rats between postnatal days 2 and 7 together with a considerable fat mobilization in brown adipose tissue, TAT-CNTF lacked such side effects. Together, these results indicate that rhCNTF fused with the protein transduction domain/TAT retains neurotrophic activity in the absence of CNTFs cytokine-like side effects and may be a promising candidate for the treatment of motor neuron and other neurodegenerative diseases.
Asunto(s)
Factor Neurotrófico Ciliar/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Neuropatía Ciática/tratamiento farmacológico , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/metabolismo , Animales , Animales Recién Nacidos , Axotomía/métodos , Peso Corporal/efectos de los fármacos , Recuento de Células/métodos , Células Cultivadas , Embrión de Pollo , Factor Neurotrófico Ciliar/metabolismo , Cricetinae , Cricetulus , Relación Dosis-Respuesta a Droga , Ganglios Espinales/citología , Proteínas Fluorescentes Verdes/genética , Humanos , Neuronas Motoras/efectos de los fármacos , Neuronas Motoras/fisiología , Ratas , Ratas Wistar , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/uso terapéutico , Factor de Transcripción STAT3/metabolismo , Neuropatía Ciática/etiología , Neuropatía Ciática/fisiopatología , Células Receptoras Sensoriales/efectos de los fármacos , Células Receptoras Sensoriales/fisiología , Transducción Genética/métodos , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/uso terapéuticoRESUMEN
CNTF is a cytokine that promotes survival and/or differentiation in many cell types, including rat pancreatic islets. In this work, we studied the mechanism of CNTF signal in neonatal rats pancreatic islets isolated by the collagenase method and cultured for 3 days in RPMI medium without (CTL) or with 1 nM of CNTF. The medium contained, when necessary, specific inhibitors of the PI3K, MAPK and JAK/STAT3 pathways. mRNA expression (RT-PCR) and protein phosphorylation (Western blot) of Akt, ERK1/2 and STAT3, and SOCS-3 (RT-PCR and Western blot), as well as glucose-stimulated insulin secretion (GSIS) (Radioimmunoassay), were analyzed. Our results showed that Akt, ERK1 and STAT3 mRNA expression, as well as phosphorylated Akt and ERK1/2, was not affected by CNTF treatment. CNTF increased cytoplasmatic and nuclear phosphorylated STAT3, and the SOCS3 mRNA and protein expression. In addition, CNTF lowered apoptosis and impaired GSIS. These effects were blocked by the JAK inhibitor, AG490 and by the STAT3 inhibitor Curcumin, but not by the MAPK inhibitor, PD98059, nor by the PI3K inhibitor, Wortmannin. In conclusion, CNTF signals through the JAK2/STAT3 cascade, increases SOCS3 expression, impairs GSIS and protects neonatal pancreatic rat islets from cytokine-induced apoptosis. These findings indicate that CNTF may be a potential therapeutic tool against Type 1 and/or Type 2 diabetes.