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The Glycine Transporter Type 1 (GlyT1) significantly impacts central nervous system functions, influencing glycinergic and glutamatergic neurotransmission. Bitopertin, the first GlyT1 inhibitor in clinical trials, was developed for schizophrenia treatment but showed limited efficacy. Despite this, bitopertin's repositioning could advance treating various pathologies. This study aims to understand bitopertin's mechanism of action using computational methods, exploring off-target effects, and providing a comprehensive pharmacological profile. Similarity Ensemble Approach (SEA) and SwissTargetPrediction initially predicted targets, followed by molecular modeling on SWISS-MODEL and GalaxyWeb servers. Binding sites were identified using PrankWeb, and molecular docking was performed with DockThor and GOLD software. Molecular dynamics analyses were conducted on the Visual Dynamics platform. Reverse screening on SEA and SwissTargetPrediction identified GlyT1 (SLC6A9), GlyT2 (SLC6A5), PROT (SLC6A7), and DAT (SLC6A3) as potential bitopertin targets. Homology modeling on SwissModel generated high-resolution models, optimized further on GalaxyWeb. PrankWeb identified similar binding sites in GlyT1, GlyT2, PROT, and DAT, indicating potential interaction. Docking studies suggested bitopertin's interaction with GlyT1 and proximity to GlyT2 and PROT. Molecular dynamics confirmed docking results, highlighting bitopertin's target stability beyond GlyT1. The study concludes that bitopertin potentially interacts with multiple SLC6 family targets, indicating a broader pharmacological property.
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Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid-ß, leading to N-methyl-D-aspartate (NMDA) receptor-dependent synaptic depression, spine elimination, and memory deficits. Glycine transporter type 1 (GlyT1) modulates glutamatergic neurotransmission via NMDA receptors (NMDAR), presenting a potential alternative therapeutic approach for AD. This study investigates the neuroprotective potential of GlyT1 inhibition in an amyloid-ß-induced AD mouse model. C57BL/6 mice were treated with N-[3-([1,1-Biphenyl]-4-yloxy)-3-(4-fluorophenyl)propyl]-N-methylglycine (NFPS), a GlyT1 inhibitor, 24 h prior to intrahippocampal injection of amyloid-ß. NFPS pretreatment prevented amyloid-ß-induced cognitive deficits in short-term and long-term memory, evidenced by novel object recognition and spatial memory tasks. Moreover, NFPS pretreatment curbed microglial activation, astrocytic reactivity, and subsequent neuronal damage from amyloid-ß injection. An extensive label-free quantitative UPLC-MSE proteomic analysis was performed on the hippocampi of mice treated with NFPS. In proteomics, KEGG enrichment analysis revealed increased in dopaminergic synapse, purine-containing compound biosynthetic process and long-term potentiation, and a reduction in Glucose catabolic process and glycolytic process pathways. The western blot analysis confirmed that NFPS treatment elevated BDNF levels, correlating with enhanced TRKB phosphorylation and mTOR activation. Moreover, NFPS treatment reduced the GluN2B expression after 6 h, which was associated with an increase on CaMKIV and CREB phosphorylation. Collectively, these findings demonstrate that GlyT1 inhibition by NFPS activates diverse neuroprotective pathways, enhancing long-term potentiation signaling and countering amyloid-ß-induced hippocampal damage.
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Doença de Alzheimer , Peptídeos beta-Amiloides , Proteínas da Membrana Plasmática de Transporte de Glicina , Hipocampo , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores , Animais , Doença de Alzheimer/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/prevenção & controle , Peptídeos beta-Amiloides/metabolismo , Masculino , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Camundongos , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Modelos Animais de Doenças , Sarcosina/análogos & derivados , Sarcosina/farmacologia , Sarcosina/uso terapêutico , Neuroproteção/efeitos dos fármacos , Neuroproteção/fisiologiaRESUMO
The glutamatergic hypothesis of schizophrenia suggests a correlation between NMDA receptor hypofunction and negative psychotic symptoms. It has been observed that the expression of the proline transporter (PROT) in the central nervous system (CNS) is associated with glutamatergic neurotransmission, as L-proline has the capacity to activate and modulate AMPA and NMDA receptors. In this study, we aimed to investigate whether inhibition of proline transporters could enhance glutamatergic neurotransmission and potentially exhibit antipsychotic effects in an experimental schizophrenia model. Using molecular dynamics analysis in silico, we validated an innovative PROT inhibitor, LQFM215. We quantified the cytotoxicity of LQFM215 in the Lund human mesencephalic cell line (LUHMES). Subsequently, we employed the ketamine-induced psychosis model to evaluate the antipsychotic potential of the inhibitor, employing behavioral tests including open-field, three-chamber interaction, and prepulse inhibition (PPI). Our results demonstrate that LQFM215, at pharmacologically active concentrations, exhibited negligible neurotoxicity when astrocytes were co-cultured with neurons. In the ketamine-induced psychosis model, LQFM215 effectively reduced hyperlocomotion and enhanced social interaction in a three-chamber social approach task across all administered doses. Moreover, the compound successfully prevented the ketamine-induced disruption of sensorimotor gating in the PPI test at all tested doses. Overall, these findings suggest that PROT inhibition could serve as a potential therapeutic target for managing symptoms of schizophrenia model.
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Sistemas de Transporte de Aminoácidos Neutros , Antipsicóticos , Ketamina , Esquizofrenia , Humanos , Antipsicóticos/farmacologia , Antipsicóticos/uso terapêutico , Esquizofrenia/induzido quimicamente , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , Ketamina/farmacologia , Ketamina/uso terapêutico , Sistemas de Transporte de Aminoácidos Neutros/uso terapêutico , Receptores de N-Metil-D-AspartatoRESUMO
BACKGROUND: L-proline transporter (PROT/SLC6A7) is closely associated with glutamatergic neurotransmission, where L-proline modulates the NMDA receptor (NMDAR) function. NMDAR-mediated excitotoxicity is a primary cause of neuronal death following stroke, which is triggered by the uncontrolled release of glutamate during the ischemic process. After ischemic stroke, L-proline levels show a reduction in the plasma, but high circulating levels of this molecule indicate good functional recovery. This work aimed to produce new PROT inhibitors and explore their effects on ischemic stroke. METHODS: Initially, we built a three-dimensional model of the PROT protein and run a molecular docking with the newly designed compounds (LQFM215, LQFM216, and LQFM217). Then, we synthesized new PROT inhibitors by molecular hybridization, and proline uptake was measured in ex vivo and in vivo models. The behavioral characterization of the treated mice was performed by the open-field test, elevated plus-maze, Y-maze, and forced swimming test. We used the permanent middle cerebral artery occlusion (MCAO) model to study the ischemic stroke damage and analyzed the motor impairment with limb clasping or cylinder tests. RESULTS: LQFM215 inhibited proline uptake in hippocampal synaptosomes, and the LQFM215 treatment reduced proline levels in the mouse hippocampus. LQFM215 reduced the locomotor and exploratory activity in mice and did not show any anxiety-related or working memory impairments. In the MCAO model, LQFM215 pre-treatment and treatment reduced the infarcted area and reduced motor impairments in the cylinder test and limb clasping. CONCLUSIONS: This dataset suggests that the new compounds inhibit cerebral L-proline uptake and that LQFM215 promotes neuroprotection and neuro-repair in the acute ischemic stroke model.
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Isquemia Encefálica , AVC Isquêmico , Camundongos , Animais , AVC Isquêmico/complicações , Neuroproteção , Simulação de Acoplamento Molecular , Infarto da Artéria Cerebral Média/complicações , Receptores de N-Metil-D-Aspartato , Prolina/farmacologia , Isquemia Encefálica/complicações , Modelos Animais de DoençasRESUMO
Glioma is the prevalent aggressive primary brain tumor, with a very poor prognosis. The absence of advanced understanding of the roles played by the cells within the glioma microenvironment limits the development of effective drugs. A recent study indicates that periostin expressed by pericytes is crucial for glioma angiogenesis. Here, we describe succinctly the results and implications of this discovery in what we know about pericytes within the glioma microenvironment. The emerging knowledge from this work will benefit the development of therapies for gliomas.
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Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/patologia , Glioma/patologia , Humanos , Morfogênese , Neovascularização Patológica/patologia , Pericitos/patologia , Microambiente TumoralRESUMO
Astrocytes are highly specialized glial cells responsible for trophic and metabolic support of neurons. They are associated to ionic homeostasis, the regulation of cerebral blood flow and metabolism, the modulation of synaptic activity by capturing and recycle of neurotransmitters and maintenance of the blood-brain barrier. During injuries and infections, astrocytes act in cerebral defense through heterogeneous and progressive changes in their gene expression, morphology, proliferative capacity, and function, which is known as reactive astrocytes. Thus, reactive astrocytes release several signaling molecules that modulates and contributes to the defense against injuries and infection in the central nervous system. Therefore, deciphering the complex signaling pathways of reactive astrocytes after brain damage can contribute to the neuroinflammation control and reveal new molecular targets to stimulate neurorepair process. In this review, we present the current knowledge about the role of astrocytes in brain damage and repair, highlighting the cellular and molecular bases involved in synaptogenesis and neurogenesis. In addition, we present new approaches to modulate the astrocytic activity and potentiates the neurorepair process after brain damage.
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TRPV1 is a cation channel expressed in peripheral nociceptive pathways and its activation can trigger nociception signals to the brain. Ketamine is an intravenous anesthetic routinely used for anesthesia induction and with potent analgesic activity. Despite its proven depressant action on peripheral sensory pathways, the relationship between ketamine and TRPV1 receptors is still unclear. In this study, we evaluated the effect of ketamine injected peripherally in a rat model of spontaneous pain induced by capsaicin. We also investigated the effect of ketamine on Ca2+ transients in cultured dorsal root ganglia (DRG) neurons and HEK293 cells expressing the TRPV1 receptor (HEK-TRPV1 cells). Intraplantar administration of ketamine caused an unexpected increase in nocifensive behavior induced by capsaicin. Incubation of HEK-TRPV1 cells with 10 µM ketamine increased TRPV1 and PKCÑ phosphorylation. Ketamine potentiated capsaicin-induced Ca2+ transients in HEK-TRPV1 cells and DRG neurons. Ketamine also prevented TRPV1 receptor desensitization induced by successive applications of capsaicin. ÑV1-2, a PKCÑ inhibitor, reduced potentiation of capsaicin-induced Ca2+ transients by ketamine. Taken together, our data indicate that ketamine potentiates TRPV1 receptor sensitivity to capsaicin through a mechanism dependent on PKCÑ activity.
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Ketamina/administração & dosagem , Nociceptividade/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Canais de Cátion TRPV/agonistas , Canais de Cátion TRPV/metabolismo , Animais , Capsaicina/administração & dosagem , Células Cultivadas , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Células HEK293 , Humanos , Masculino , Nociceptividade/fisiologia , Ratos , Ratos Wistar , Transdução de Sinais/fisiologiaRESUMO
Glycine transporters (GlyTs) are Na+/Cl--dependent neurotransmitter transporters, responsible for l-glycine uptake into the central nervous system. GlyTs are members of the solute carrier family 6 (SLC6) and comprise glycine transporter type 1 (SLC6A9; GlyT1) and glycine transporter type 2 (SLC6A5; Glyt2). GlyT1 and GlyT2 are expressed on both astrocytes and neurons, but their expression pattern in brain tissue is foremost related to neurotransmission. GlyT2 is markedly expressed in brainstem, spinal cord and cerebellum, where it is responsible for glycine uptake into glycinergic and GABAergic terminals. GlyT1 is abundant in neocortex, thalamus and hippocampus, where it is expressed in astrocytes, and involved in glutamatergic neurotransmission. Consequently, inhibition of GlyT1 transporters can modulate glutamatergic neurotransmission through NMDA receptors, suggesting an alternative therapeutic strategy. In this review, we focus on recent progress in the understanding of GlyTs role in brain function and in various diseases, such as epilepsy, hyperekplexia, neuropathic pain, drug addiction, schizophrenia and stroke, as well as in neurodegenerative disorders.
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Proteínas da Membrana Plasmática de Transporte de Glicina , Transmissão Sináptica , Astrócitos/metabolismo , Glicina , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Humanos , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
PURPOSE: Although the pathophysiological response of cardiac tissue to pro-hypertrophic stimulus is well characterized, a comprehensive characterization of the molecular events underlying the pathological hypertrophy in cardiomyocytes during the early compensated cardiac hypertrophy is currently lacking. EXPERIMENTAL DESIGN: A quantitative label-free proteomic analysis of cardiomyocytes isolated was conducted from mice treated subcutaneously with isoproterenol (ISO) during 7 days in comparison with cardiomyocytes from control animals (CT). RESULTS: Canonical pathway analysis of dysregulated proteins indicated that ISO-hypertrophy drives the activation of actin cytoskeleton and integrin-linked kinase (ILK) signaling, and inhibition of the sirtuin signaling. Alteration in cardiac contractile function and calcium signaling are predicted as downstream effects of ISO-hypertrophy probably due to the upregulation of key elements such as myosin-7 (MYH7). Confocal microscopy corroborated that indeed ISO-treatment led to increased abundance of MYH7. Potential early markers for cardiac hypertrophy as APBB1, GOLGA4, HOOK1, KATNA1, KIFBP, MAN2B2, and SLC16A1 are also reported. CONCLUSIONS AND CLINICAL RELEVANCE: The data consist in a complete molecular mapping of ISO-induced compensated cardiac hypertrophy model at cardiomyocyte level. Marker candidates reported may assist early diagnosis of cardiac hypertrophy and ultimately heart failure.
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Cardiomegalia/metabolismo , Isoproterenol/toxicidade , Miócitos Cardíacos/metabolismo , Proteoma/genética , Transdução de Sinais , Actinas/genética , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/genética , Cardiomegalia/fisiopatologia , Regulação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Cadeias Pesadas de Miosina/genética , Proteínas Serina-Treonina Quinases/metabolismo , ProteômicaRESUMO
Lapachol is a plant-derived naphthoquinone that kills several types of cancer cells. Derivatives of this molecule may therefore prove to be useful chemotherapeutic agents. In this study, we explored whether glycosylation increases the cytotoxic potency of lapachol towards HL-60 human leukemia cells. Two beta-glycosides were synthesized and characterized: LA4A (lapachol-ß-glucoside) and LA4C (lapachol-N-acetylglucosamine-ß-glucoside). The sugar moieties of both novel molecules were per-acetylated to facilitate cellular uptake. The IC50 values (in µM) for LA4A (5.7) and LA4C (5.3) were lower than those for lapachol (25). LA4A and LA4C triggered typical signs of apoptosis, such as the exposure of phosphatidylserine on the outside of cells, chromatin condensation, DNA fragmentation and a decrease of the mitochondrial transmembrane potential (ΔΨm) prior to cell lysis. Moreover, DNA fragmentation triggered by the lapachol-glycosides was reduced by pre-treatment with the caspase inhibitor, z-VAD-fmk. While LA4A and LA4C activated caspases-3, -8 and -9, lapachol failed to activate these apoptotic proteases, even when used at high concentrations. Finally, the toxicity of lapachol and its derivatives was also tested on non-tumor cells. We used human peripheral neurons (PeriTox test) to evaluate the side effect potential of these compounds. LA4C was clearly less toxic than LA4A. We conclude that LA4C had the most favorable profile as drug candidate (high tumor cell toxicity, reduced neurotoxicity). In general, this study shows that the cytotoxicity of lapachol towards HL-60 can be enhanced by glycosylation, and that the therapeutic ratio may be modified by the type of sugar added.
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Antineoplásicos/toxicidade , Naftoquinonas/toxicidade , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Glicosilação/efeitos dos fármacos , Células HL-60 , HumanosRESUMO
Vascular dementia (VD) is a major cognitive disorder originated from a blood flow disruption in the brain. This process leads to chronic cerebral ischemia that deeply affects neuronal tissues and lipid homeostasis. The understanding of cerebral lipid dynamics during chronic ischemia can reveal biomarkers and novel pharmacological targets for the treatment of VD. In this study, we used the Desorption Electrospray Ionization - imaging mass spectrometry (DESI-IMS) technique to map lipids in the rat brain tissues after bilateral common carotid artery occlusion (BCCAO) rat model of chronic cerebral hypoperfusion. The brain imaging enabled the detection of differences in lipids from ischemic and non-ischemic brains. The analysis demonstrated that arachidonic acid (ARA), docosahexaenoic acid (DHA), dihomo-γ-linolenic acid, hydroxyeicosatetraenoic (HETE)-Ala and glycerophosphoethanolamine levels were significantly reduced in the hippocampus and cortex of animals submitted to BCCAO model when compared to control animals. Decanoic acid was increased after 30â¯days of BCCAO model. Partial least squares discriminant analysis (PLS-DA) could discriminate between BCCAO group and the control group, in which γ-linolenic acid (m/z 277) ion and stearic acid (m/z 283) had the highest discrimination potential. Taken together, these findings indicate that lipid dynamics are altered in chronic ischemia-induced by BCCAO in rats and indicate potential biomarkers and pharmacological targets for VD.
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Isquemia Encefálica/diagnóstico por imagem , Córtex Cerebral/patologia , Hipocampo/patologia , Lipídeos/análise , Animais , Doenças das Artérias Carótidas/patologia , Doença Crônica , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Masculino , Neurônios/patologia , Ratos WistarRESUMO
ST-segment elevation myocardial infarction (STEMI) is the most severe form of myocardial infarction (MI) and the main contributor to morbidity and mortality caused by MI worldwide. Frequently, STEMI is caused by complete and persistent occlusion of a coronary artery by a blood clot, which promotes heart damage. STEMI impairment triggers changes in gene transcription, protein expression, and metabolite concentrations, which grants a biosignature to the heart dysfunction. There is a major interest in identifying novel biomarkers that could improve the diagnosis of STEMI. In this study, the phenotypic characterization of STEMI patients (n = 15) and healthy individuals (n = 19) was performed, using a target metabolomics approach. Plasma samples were analyzed by UPLC-MS/MS (ultra-high-performance liquid chromatography-tandem mass spectrometry) and FIA-MS (MS-based flow injection analysis). The goal was to identify novel plasma biomarkers and metabolic signatures underlying STEMI. Concentrations of phosphatidylcholines, lysophosphatidylcholines, sphingomyelins, and biogenic amines were altered in STEMI patients in relation to healthy subjects. Also, after multivariate analysis, it was possible to identify alterations in the glycerophospholipids, alpha-linolenic acid, and sphingolipid metabolisms in STEMI patients.
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Metaboloma , Infarto do Miocárdio com Supradesnível do Segmento ST/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Aminas Biogênicas/sangue , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fosfatidilcolinas/sangue , Esfingomielinas/sangueRESUMO
Mesenchymal stem cells (MSCs), also known as multipotent mesenchymal stromal stem cells, are found in the perivascular space of several tissues. These cells have been subject of intense research in the last decade due to their low teratogenicity, as well as their ability to differentiate into mature cells and to secrete immunomodulatory and trophic factors. However, they usually promote only a modest benefit when transplanted in experimental disease models, one of the limitations for their clinical application. The CRISPR-Cas system, in turn, is highlighted as a simple and effective tool for genetic engineering. This system was tested in clinical trials over a relatively short period of time after establishing its applicability to the edition of the mammalian cell genome. Similar to the research evolution in MSCs, the CRISPR-Cas system demonstrated inconsistencies that limited its clinical application. In this review, we outline the evolution of MSC research and its applicability, and the progress of the CRISPR-Cas system from its discovery to the most recent clinical trials. We also propose perspectives on how the CRISPR-Cas system may improve the therapeutic potential of MSCs, making it more beneficial and long lasting.
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Sistemas CRISPR-Cas , Edição de Genes , Imunomodulação , Células-Tronco Mesenquimais/imunologia , Animais , Modelos Animais de Doenças , HumanosRESUMO
Neurogenesis is the process by which new neurons are generated in the brain. Neural stem cells (NSCs) are differentiated into neurons, which are integrated into the neural network. Nowadays, pluripotent stem cells, multipotent stem cells, and induced pluripotent stem cells can be artificially differentiated into neurons utilizing several techniques. Specific transcriptional profiles from NSCs during differentiation are frequently used to approach and observe phenotype alteration and functional determination of neurons. In this context, the role of non-coding RNA, transcription factors and epigenetic changes in neuronal development and differentiation has gained importance. Epigenetic elucidation has become a field of intense research due to distinct patterns of normal conditions and different neurodegenerative disorders, which can be explored to develop new diagnostic methods or gene therapies. In this review, we discuss the complexity of transcription factors, non-coding RNAs, and extracellular vesicles that are responsible for guiding and coordinating neural development.
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Diferenciação Celular/genética , Epigênese Genética , Neurônios/citologia , Neurônios/metabolismo , Transdução de Sinais/genética , Animais , Exossomos/metabolismo , Humanos , RNA não Traduzido/genética , RNA não Traduzido/metabolismoRESUMO
N-(2-butanoyloxyethyl)-4-(chloromethyl)-3-nitrobenzamide (NBCN) is a nitroaromatic bioreducible compound with cytotoxic effects in cancer cell lines. The aim of this work was to investigate the molecular mechanisms involved in cell death promoted by NBCN in HL60 cells. We observed that NBCN treatment increased intracellular ROS and reduced mitochondria membrane potential (ΔΨm). NBCN treatment also induced morphological changes, phosphatidylserine exposure, cell cycle arrest in G2/M-phase, DNA condensation and fragmentation, but it did not show cytotoxic effects on normal human peripheral blood mononuclear cells (PBMCs). NBCN-induced caspase 3- and 9-dependent DNA fragmentation, which was blocked by pretreatment with the broad-spectrum caspase inhibitor, z-VAD-fmk. Flow cytometry analysis demonstrated that NBCN also increased of the number of autophagic vesicles in HL60 cells, which was not observed when cells were pre-treated with bafilomycin A1. Taken together, these results indicate that NBCN triggered the mitochondrial apoptotic pathway and led to the onset of autophagic cell death, which contributed to its cytotoxic effects.
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Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Benzamidinas/toxicidade , Clorometilcetonas de Aminoácidos/farmacologia , Benzamidinas/química , Inibidores de Caspase/farmacologia , Caspases/metabolismo , Células Cultivadas , Fragmentação do DNA/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HL-60 , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Macrolídeos/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Cell proliferation is orchestrated through diverse proteins related to calcium (Ca(2+)) signaling inside the cell. Cellular Ca(2+) influx that occurs first by various mechanisms at the plasma membrane, is then followed by absorption of Ca(2+) ions by mitochondria and endoplasmic reticulum, and, finally, there is a connection of calcium stores to the nucleus. Experimental evidence indicates that the fluctuation of Ca(2+) from the endoplasmic reticulum provides a pivotal and physiological role for cell proliferation. Ca(2+) depletion in the endoplasmatic reticulum triggers Ca(2+) influx across the plasma membrane in an phenomenon called store-operated calcium entries (SOCEs). SOCE is activated through a complex interplay between a Ca(2+) sensor, denominated STIM, localized in the endoplasmic reticulum and a Ca(2+) channel at the cell membrane, denominated Orai. The interplay between STIM and Orai proteins with cell membrane receptors and their role in cell proliferation is discussed in this review.
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Canais de Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Proliferação de Células/fisiologia , Proteínas de Membrana/metabolismo , Animais , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Retículo Endoplasmático/metabolismo , Humanos , Mitocôndrias/metabolismoRESUMO
Brain preconditioning is a protective mechanism, which can be activated by sub-lethal stimulation of the NMDA receptors (NMDAR) and be used to achieve neuroprotection against stroke and neurodegenerative diseases models. Inhibitors of glycine transporters type 1 modulate glutamatergic neurotransmission through NMDAR, suggesting an alternative therapeutic strategy of brain preconditioning. The aim of this work was to evaluate the effects of brain preconditioning induced by NFPS, a GlyT1 inhibitor, against NMDA-induced excitotoxicity in mice hippocampus, as well as to study its neurochemical mechanisms. C57BL/6 mice (male, 10-weeks-old) were preconditioned by intraperitoneal injection of NFPS at doses of 1.25, 2.5 or 5.0 mg/kg, 24 h before intrahippocampal injection of NMDA. Neuronal death was evaluated by fluoro jade C staining and neurochemical parameters were evaluated by gas chromatography-mass spectrometry, scintillation spectrometry and western blot. We observed that NFPS preconditioning reduced neuronal death in CA1 region of hippocampus submitted to NMDA-induced excitotoxicity. The amino acids (glycine and glutamate) uptake and content were increased in hippocampus of animals treated with NFPS 5.0 mg/kg, which were associated to an increased expression of type-2 glycine transporter (GlyT2) and glutamate transporters (EAAT1, EAAT2 and EAAT3). The expression of GlyT1 was reduced in animals treated with NFPS. Interestingly, the preconditioning reduced expression of GluN2B subunits of NMDAR, whereas did not change the expression of GluN1 or GluN2A in all tested doses. Our study suggests that NFPS preconditioning induces resistance against excitotoxicity, which is associated with neurochemical changes and reduction of GluN2B-containing NMDAR expression.
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Agonistas de Aminoácidos Excitatórios/toxicidade , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , N-Metilaspartato/toxicidade , Síndromes Neurotóxicas , Sarcosina/análogos & derivados , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Esquema de Medicação , Fluoresceínas , Cromatografia Gasosa-Espectrometria de Massas , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Glicina/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/lesões , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/patologia , Síndromes Neurotóxicas/prevenção & controle , Sarcosina/administração & dosagem , Fatores de Tempo , Trítio/metabolismoRESUMO
The role of physical exercise as a neuroprotective agent against ischemic injury has been extensively discussed. Nevertheless, the mechanisms underlying the effects of physical exercise on cerebral ischemia remain poorly understood. Here, we investigate the hypothesis that physical exercise increases ischemic tolerance by decreasing the induction of cellular apoptosis and glutamate release. Rats (n = 50) were submitted to a swimming exercise protocol for 8 weeks. Hippocampal slices were then submitted to oxygen and glucose deprivation. Cellular viability, pro-apoptotic markers (Caspase 8, Caspase 9, Caspase 3, and apoptosis-inducing factor), and glutamate release were analyzed. The percentage of cell death, the amount of glutamate release, and the expression of the apoptotic markers were all decreased in the exercise group when compared to the sedentary group after oxygen and glucose deprivation. Our results suggest that physical exercise protects hippocampal slices from the effects of oxygen and glucose deprivation, probably by a mechanism involving both the decrease of glutamatergic excitotoxicity and apoptosis induction.
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Fator de Indução de Apoptose/metabolismo , Caspases/metabolismo , Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Condicionamento Físico Animal/fisiologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Peso Corporal/fisiologia , Hipóxia Celular/fisiologia , Sobrevivência Celular/fisiologia , Masculino , Técnicas de Cultura de Órgãos , Condicionamento Físico Animal/métodos , Ratos , Ratos WistarRESUMO
The analysis of amino acid levels is crucial for neuroscience studies because of the roles of these molecules as neurotransmitters and their influence on behavior. The present study describes the distribution and levels of 16 amino acids (alanine, asparagine, aspartic acid, cysteine, glycine, glutamic acid, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, valine, and threonine) in brain tissues (prefrontal cortex, striatum, hippocampus and cerebellum) and the serum. Neurochemical analysis was performed on Wistar rats and C57BL/6 mice using an efficient method for extraction, a fast microwave-assisted derivatization and gas chromatography-mass spectrometry analysis. The amino acid concentration varied across brain regions for 14 of the 16 analyzed molecules, with detection limits ranging from 0.02±0.005µmolL(-1) to 7.07±0.05µmolL(-1). In rats, the concentrations of alanine, glycine, methionine, serine and threonine were higher in prefrontal cortex than in other areas, whereas in mice, the concentrations of glutamic acid, leucine and proline were highest in the hippocampus. In conclusion, this study provides a cerebral profile of amino acids in brain regions and the serum of rats and mice.
Assuntos
Aminoácidos/metabolismo , Encéfalo/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Aminoácidos/sangue , Animais , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos WistarRESUMO
In recent decades, the elderly population in Brazil has grown rapidly, as has concern for the health of this population. Institutionalization in nursing homes has appeared as an alternative form of health care for frail elderly that live alone. The present study evaluated the pharmacotherapy and inappropriate drug prescriptions for institutionalized elderly patients living in long-term institutions in southeastern Brazil. This research was conducted at five institutions with a total sample of 151 individuals aged at least 60 years. Databases were used to identify drug interactions, defined daily dose and inappropriate prescriptions. The prevalence of drug intake among the elderly was 95.36%, and there were an average of 3.31 ± 1.80 drug prescriptions per individual. Based on Beers criteria, the prevalence of inappropriate prescriptions was 25.83%. In addition, 70.2% of prescriptions were prescribed at a higher dosage than the defined daily dose (ATC/WHO). Potential drug interactions were identified for 54.11% of prescriptions; 81.42% of these were of moderate severity. The main inappropriate drugs were prescribed for cardiovascular and nervous system problems. Institutionalized elderly individuals presented a high consumption and misuse of medications, requiring professional intervention to monitor prescriptions and improve the quality of service for this population.
Nas últimas décadas, o número de idosos no Brasil cresceu rapidamente, bem como, a preocupação com a saúde desta parcela da população. Neste cenário, a institucionalização em casas de repouso aparece como uma alternativa para os cuidados com a saúde dos idosos debilitados ou que vivem sozinhos. O presente estudo avaliou a farmacoterapia e a prescrição inadequada para idosos que residem em instituições de longa permanência no sudeste do Brasil. Esta pesquisa foi realizada em cinco instituições, totalizando uma amostra de 151 indivíduos com idade a partir de 60 anos. O banco de dados foi analisado para identificação de interações medicamentosas, dose diária definida e critérios de Beers. Dentre os indivíduos avaliados, 95,36% consomem algum tipo de medicamento, sendo 3,31 ± 1,80 medicamentos prescritos por indivíduo. Com base nos critérios de Beers, a prevalência de prescrições inapropriadas foi de 25,83%, sendo também encontradas 70,2% das prescrições com doses superiores à dose diária definida (ATC/WHO). Interações medicamentosas potenciais estavam presentes em 54,11% das prescrições, sendo 81,42% com grau moderado de gravidade. Os principais medicamentos inapropriados foram prescritos para problemas cardiovasculares e do sistema nervoso. Os idosos institucionalizados apresentam alto consumo e uso inadequado de medicamentos, sendo necessária a intervenção profissional para monitorar as prescrições médicas e melhorar a qualidade do serviço de distribuição de medicamentos a esta parte da população.