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1.
Biomaterials ; 312: 122707, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39121729

RESUMEN

Polypyrimidine tract-binding protein 1 (PTBP1) regulates numerous alternative splicing events during tumor progression and neurogenesis. Previously, PTBP1 downregulation was reported to convert astrocytes into functional neurons; however, how PTBP1 regulates astrocytic physiology remains unclear. In this study, we revealed that PTBP1 modulated glutamate uptake via ATP1a2, a member of Na+/K+-ATPases, and glutamate transporters in astrocytes. Ptbp1 knockdown altered mitochondrial function and energy metabolism, which involved PTBP1 regulating mitochondrial redox homeostasis via the succinate dehydrogenase (SDH)/Nrf2 pathway. The malfunction of glutamate transporters following Ptbp1 knockdown resulted in enhanced excitatory synaptic transmission in the cortex. Notably, we developed a biomimetic cationic triblock polypeptide system, i.e., polyethylene glycol44-polylysine30-polyleucine10 (PEG44-PLL30-PLLeu10) with astrocytic membrane coating to deliver Ptbp1 siRNA in vitro and in vivo, which approach allowed Ptbp1 siRNA to efficiently cross the blood-brain barrier and target astrocytes in the brain. Collectively, our findings suggest a framework whereby PTBP1 serves as a modulator in glutamate transport machinery, and indicate that biomimetic methodology is a promising route for in vivo siRNA delivery.


Asunto(s)
Astrocitos , Ácido Glutámico , Ribonucleoproteínas Nucleares Heterogéneas , Homeostasis , Factor 2 Relacionado con NF-E2 , Proteína de Unión al Tracto de Polipirimidina , ARN Interferente Pequeño , Animales , Astrocitos/metabolismo , Ácido Glutámico/metabolismo , Proteína de Unión al Tracto de Polipirimidina/metabolismo , Proteína de Unión al Tracto de Polipirimidina/genética , Factor 2 Relacionado con NF-E2/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas/genética , Ratones , Transducción de Señal , Membrana Celular/metabolismo , Ratones Endogámicos C57BL , Masculino , Humanos , Mitocondrias/metabolismo
2.
Nat Commun ; 15(1): 8051, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39277606

RESUMEN

Bestrophin-1 (Best1) is an anion channel genetically linked to vision-threatening retinal degenerative channelopathies. Here, we identify interactions between Best1 and both isoforms of glutamic acid decarboxylases (GAD65 and GAD67), elucidate the distinctive influences of GAD65 and GAD67 on Best1's permeability to various anions/neurotransmitters, discover the functionality of Best1 as a γ-Aminobutyric acid (GABA) type A receptor, and solve the structure of GABA-bound Best1. GAD65 and GAD67 both promote Best1-mediated Cl- currents, but only GAD65 drastically enhances the permeability of Best1 to glutamate and GABA, for which GAD67 has no effect. GABA binds to Best1 on an extracellular site and stimulates Best1-mediated Cl- currents at the nano-molar concentration level. The physiological role of GAD65 as a cell type-specific binding partner and facilitator of Best1 is demonstrated in retinal pigment epithelial cells. Together, our results reveal critical regulators of Best1 and inform a network of membrane transport metabolons formed between bestrophin channels and glutamate metabolic enzymes.


Asunto(s)
Bestrofinas , Glutamato Descarboxilasa , Ácido Glutámico , Ácido gamma-Aminobutírico , Glutamato Descarboxilasa/metabolismo , Glutamato Descarboxilasa/genética , Bestrofinas/metabolismo , Bestrofinas/genética , Humanos , Ácido gamma-Aminobutírico/metabolismo , Ácido Glutámico/metabolismo , Células HEK293 , Animales , Epitelio Pigmentado de la Retina/metabolismo , Neurotransmisores/metabolismo , Unión Proteica , Receptores de GABA-A/metabolismo , Receptores de GABA-A/genética
3.
Sci Rep ; 14(1): 20575, 2024 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-39232046

RESUMEN

Glioblastoma multiforme (GBM) is the most aggressive type of cancer in the brain and has an inferior prognosis because of the lack of suitable medicine, largely due to its tremendous invasion. GBM has selfish metabolic pathways to promote migration, invasion, and proliferation compared to normal cells. Among various metabolic pathways, NAD (nicotinamide adenine dinucleotide) is essential in generating ATP and is used as a resource for cancer cells. LbNOX (Lactobacillus brevis NADH oxidase) is an enzyme that can directly manipulate the NAD+/NADH ratio. In this study, we found that an increased NAD+/NADH ratio by LbNOX or mitoLbNOX reduced intracellular glutamate and calcium responses and reduced invasion capacity in GBM. However, the invasion was not affected in GBM by rotenone, an ETC (Electron Transport Chain) complex I inhibitor, or nicotinamide riboside, a NAD+ precursor, suggesting that the crucial factor is the NAD+/NADH ratio rather than the absolute quantity of ATP or NAD+ for the invasion of GBM. To develop a more accurate and effective GBM treatment, our findings highlight the importance of developing a new medicine that targets the regulation of the NAD+/NADH ratio, given the current lack of effective treatment options for this brain cancer.


Asunto(s)
Glioblastoma , Metaboloma , NAD , Glioblastoma/metabolismo , Glioblastoma/patología , NAD/metabolismo , Humanos , Línea Celular Tumoral , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Complejos Multienzimáticos/metabolismo , Levilactobacillus brevis/metabolismo , Invasividad Neoplásica , Calcio/metabolismo , Ácido Glutámico/metabolismo , Movimiento Celular , Adenosina Trifosfato/metabolismo , NADH NADPH Oxidorreductasas
4.
Nat Commun ; 15(1): 7976, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39266519

RESUMEN

Cellular homeostasis depends on the supply of metabolic energy in the form of ATP and electrochemical ion gradients. The construction of synthetic cells requires a constant supply of energy to drive membrane transport and metabolism. Here, we provide synthetic cells with long-lasting metabolic energy in the form of an electrochemical proton gradient. Leveraging the L-malate decarboxylation pathway we generate a stable proton gradient and electrical potential in lipid vesicles by electrogenic L-malate/L-lactate exchange coupled to L-malate decarboxylation. By co-reconstitution with the transporters GltP and LacY, the synthetic cells maintain accumulation of L-glutamate and lactose over periods of hours, mimicking nutrient feeding in living cells. We couple the accumulation of lactose to a metabolic network for the generation of intermediates of the glycolytic and pentose phosphate pathways. This study underscores the potential of harnessing a proton motive force via a simple metabolic network, paving the way for the development of more complex synthetic systems.


Asunto(s)
Malatos , Descarboxilación , Malatos/metabolismo , Ácido Glutámico/metabolismo , Transporte Biológico , Células Artificiales/metabolismo , Ácido Láctico/metabolismo , Lactosa/metabolismo , Escherichia coli/metabolismo , Nutrientes/metabolismo , Fuerza Protón-Motriz , Antiportadores/metabolismo , Glucólisis , Redes y Vías Metabólicas , Protones , Vía de Pentosa Fosfato
5.
Gut Microbes ; 16(1): 2401939, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39259834

RESUMEN

Early life stress alters gut microbiota and increases the risk of neuropsychiatric disorders, including social deficits and anxiety, in the host. However, the role of gut commensal bacteria in early life stress-induced neurobehavioral abnormalities remains unclear. Using the maternally separated (MS) mice, our research has unveiled a novel aspect of this complex relationship. We discovered that the reduced levels of amino acid transporters in the intestine of MS mice led to low glutamine (Gln) levels in the blood and synaptic dysfunction in the medial prefrontal cortex (mPFC). Abnormally low blood Gln levels limit the brain's availability of Gln, which is required for presynaptic glutamate (Glu) and γ-aminobutyric acid (GABA) replenishment. Furthermore, MS resulted in gut microbiota dysbiosis characterized by a reduction in the relative abundance of Lactobacillus reuteri (L. reuteri). Notably, supplementation with L. reuteri ameliorates neurobehavioral abnormalities in MS mice by increasing intestinal amino acid transport and restoring synaptic transmission in the mPFC. In conclusion, our findings on the role of L. reuteri in regulating intestinal amino acid transport and buffering early life stress-induced behavioral abnormalities provide a novel insight into the microbiota-gut-brain signaling basis for emotional behaviors.


Asunto(s)
Ansiedad , Microbioma Gastrointestinal , Estrés Psicológico , Animales , Microbioma Gastrointestinal/fisiología , Ratones , Ansiedad/microbiología , Ansiedad/metabolismo , Estrés Psicológico/microbiología , Estrés Psicológico/metabolismo , Aminoácidos/metabolismo , Masculino , Ratones Endogámicos C57BL , Sistemas de Transporte de Aminoácidos/metabolismo , Corteza Prefrontal/metabolismo , Conducta Animal , Disbiosis/microbiología , Privación Materna , Glutamina/metabolismo , Eje Cerebro-Intestino/fisiología , Transmisión Sináptica , Femenino , Ácido Glutámico/metabolismo
6.
Sci Rep ; 14(1): 18247, 2024 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-39107374

RESUMEN

In the search for the origin of Amyotrophic Lateral Sclerosis disease (ALS), we hypothesized earlier (Monselise, 2019) that D-amino acids produced by stressed microbiome may serve as inducers of the disease development. Many examples of D-amino acid accumulation under various stress conditions were demonstrated in prokaryotic and eukaryotic cells. In this work, wild-type Escherichia coli, members of the digestive system, were subjected to carbon and nitrogen starvation stress. Using NMR and LC-MS techniques, we found for the first time that D-glutamate accumulated in the stressed bacteria but not in control cells. These results together with the existing knowledge, allow us to suggest a new insight into the pathway of ALS development: D-glutamate, produced by the stressed microbiome, induces neurobiochemical miscommunication setting on C1q of the complement system. Proving this insight may have great importance in preventive medicine of such MND modern-age diseases as ALS, Alzheimer, and Parkinson.


Asunto(s)
Esclerosis Amiotrófica Lateral , Escherichia coli , Ácido Glutámico , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/microbiología , Escherichia coli/metabolismo , Ácido Glutámico/metabolismo , Humanos , Estrés Fisiológico , Complemento C1q/metabolismo , Nitrógeno/metabolismo , Carbono/metabolismo
7.
Nat Commun ; 15(1): 7572, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39217140

RESUMEN

Neurons receive thousands of inputs onto their dendritic arbour, where individual synapses undergo activity-dependent plasticity. Long-lasting changes in postsynaptic strengths correlate with changes in spine head volume. The magnitude and direction of such structural plasticity - potentiation (sLTP) and depression (sLTD) - depend upon the number and spatial distribution of stimulated synapses. However, how neurons allocate resources to implement synaptic strength changes across space and time amongst neighbouring synapses remains unclear. Here we combined experimental and modelling approaches to explore the elementary processes underlying multi-spine plasticity. We used glutamate uncaging to induce sLTP at varying number of synapses sharing the same dendritic branch, and we built a model incorporating a dual role Ca2+-dependent component that induces spine growth or shrinkage. Our results suggest that competition among spines for molecular resources is a key driver of multi-spine plasticity and that spatial distance between simultaneously stimulated spines impacts the resulting spine dynamics.


Asunto(s)
Espinas Dendríticas , Plasticidad Neuronal , Sinapsis , Animales , Plasticidad Neuronal/fisiología , Espinas Dendríticas/fisiología , Sinapsis/fisiología , Dendritas/fisiología , Calcio/metabolismo , Modelos Neurológicos , Ácido Glutámico/metabolismo , Ratas , Neuronas/fisiología , Masculino , Hipocampo/fisiología , Hipocampo/citología
8.
J Headache Pain ; 25(1): 142, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39210271

RESUMEN

BACKGROUND: Magnetic resonance spectroscopy (MRS) studies have indicated that the imbalance between gamma-aminobutyric acid (GABA) and glutamate/glutamine (Glx) levels was the potential cause of migraine development. However, the changes in the GABA and Glx levels in patients with New daily persistent headache (NDPH) remain unclear. This study aimed to investigate the changes in GABA and Glx levels in the periaqueductal gray (PAG) and dentate nucleus (DN) in patients with NDPH using the MEGA-PRESS sequence. METHODS: Twenty-one NDPH patients and 22 age- and sex-matched healthy controls (HCs) were included and underwent a 3.0T MRI examination, using the MEGA-PRESS sequence to analyze GABA and Glx levels of PAG and DN. The correlations between these neurotransmitter levels and clinical characteristics were also analyzed. RESULTS: There were no significant differences in the GABA+/Water, GABA+/Cr, Glx/Water, and Glx/Cr levels in both PAG and DN between the two groups (all p > 0.05). Moderate-severe NDPH patients had lower levels of Glx/Water (p = 0.034) and Glx/Cr (p = 0.012) in DN than minimal-mild NDPH patients. In patients with NDPH, higher Glx/Water levels in the PAG (r=-0.471, p = 0.031, n = 21) and DN (r=-0.501, p = 0.021, n = 21) and higher Glx/Cr levels in DN (r=-0.483, p = 0.026, n = 21) were found to be correlated with lower Visual Analogue Scale scores. Additionally, a positive correlation was observed between the GABA+/Cr levels in the DN and the Generalized Anxiety Disorder-7 scores (r = 0.519, p = 0.039, n = 16). CONCLUSIONS: The results of this study indicated that the GABA and Glx levels in the PAG and DN may not be the primary contributor to the development of NDPH. The correlations between certain clinical scales and the neurotransmitter levels may be derived from the NDPH related symptoms.


Asunto(s)
Núcleos Cerebelosos , Ácido Glutámico , Glutamina , Espectroscopía de Resonancia Magnética , Sustancia Gris Periacueductal , Ácido gamma-Aminobutírico , Humanos , Femenino , Masculino , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Adulto , Ácido gamma-Aminobutírico/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Sustancia Gris Periacueductal/metabolismo , Sustancia Gris Periacueductal/diagnóstico por imagen , Persona de Mediana Edad , Núcleos Cerebelosos/metabolismo , Núcleos Cerebelosos/diagnóstico por imagen , Trastornos de Cefalalgia/metabolismo , Imagen por Resonancia Magnética
9.
J Ethnopharmacol ; 335: 118676, 2024 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-39147000

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Acori graminei Rhizoma is a commonly used traditional Chinese medicine for treating TD, with its main component being calamus volatile oil. Volatile Oil from Acori graminei Rhizoma (VOA)can protect nerve cells and alleviate learning and memory disorders. However, the mechanism of anti-tic of VOA is still unclear. AIM OF THE STUDY: We aimed to explore the effects of Volatile Oil from Acori Tatarinowii Rhizoma (VOA) on striatal dopaminergic and glutamatergic systems and synaptic plasticity of rats with Tic Disorder (TD), as well as its pharmaceutical mechanism against TD. MATERIALS AND METHODS: This study involved 48 (three-week-old) Sprague Dawley (SD) rats, which were randomly divided into two primary groups: Control (8) and TD (40). Rats in the TD group were injected intraperitoneally with 3,3-iminodipropionitrile (IDPN) to construct the TD rat model. They were divided into five subgroups: Model, Tiapride, VOA-high, VOA-medium, and VOA-low (N = 8). After modeling, VOA was administrated to rats in the VOA groups through gavage (once/day for four consecutive weeks), while rats in the blank control and model groups received normal saline of the same volume. The animals' behavioral changes were reflected using the stereotypic and motor behavior scores. After interferences, patterns of striatal neurons and the density of dendritic spines were investigated using H&E and Golgi staining, and the ultrastructure of striatal synapses was examined using Transmission Electron Microscopy (TEM). Furthermore, Ca2+ content was determined using the Ca2+ detector, and Dopamine (DA) and Glutamate (GLU) contents in serum and striatum were detected through ELISA. Finally, DRD1, DRD2, AMPAR1, NMPAR1, DAT, VMAT2, CAMKⅡ, and CREB expression in the striatum was detected using Quantitative real-time PCR (qRT-PCR), Western Blotting (WB) and Immunohistochemical (IHC) methods. RESULTS: Compared to rats in the blank control and model groups, rats in the VOA groups showed lower stereotypic behavior scores. Furthermore, rats in the VOA groups exhibited relieved, neuron damage and increased quantities of neuronal dendrites and dendritic spines Additionally, based on TEM images show that, the VOA groups showed a clear synaptic structure and increased amounts of postsynaptic dense substances and synaptic vesicles. The VOA groups also exhibited reduced Ca2+ contents, and upregulation of DRD1, DRD2, DAT, AMPAR1, and NMPAR1 and downregulation of VMAT-2, CAMKⅡ, and CREB in the striatum. CONCLUSIONS: In summary, VOA could influence synaptic plasticity by tuning the dopaminergic and glutamatergic systems, thus relieving TD.


Asunto(s)
Dopamina , Ácido Glutámico , Plasticidad Neuronal , Aceites Volátiles , Ratas Sprague-Dawley , Trastornos de Tic , Animales , Plasticidad Neuronal/efectos de los fármacos , Aceites Volátiles/farmacología , Masculino , Ácido Glutámico/metabolismo , Dopamina/metabolismo , Trastornos de Tic/tratamiento farmacológico , Ratas , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Rizoma , Acorus/química
10.
Exp Physiol ; 109(9): 1572-1592, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39153228

RESUMEN

Our group previously showed that genetic or pharmacological inhibition of the cystine/glutamate antiporter, system xc -, mitigates excitotoxicity after anoxia by increasing latency to anoxic depolarization, thus attenuating the ischaemic core. Hypoxia, however, which prevails in the ischaemic penumbra, is a condition where neurotransmission is altered, but excitotoxicity is not triggered. The present study employed mild hypoxia to further probe ischaemia-induced changes in neuronal responsiveness from wild-type and xCT KO (xCT-/-) mice. Synaptic transmission was monitored in hippocampal slices from both genotypes before, during and after a hypoxic episode. Although wild-type and xCT-/- slices showed equal suppression of synaptic transmission during hypoxia, mutant slices exhibited a persistent potentiation upon re-oxygenation, an effect we termed 'post-hypoxic long-term potentiation (LTP)'. Blocking synaptic suppression during hypoxia by antagonizing adenosine A1 receptors did not preclude post-hypoxic LTP. Further examination of the induction and expression mechanisms of this plasticity revealed that post-hypoxic LTP was driven by NMDA receptor activation, as well as increased calcium influx, with no change in paired-pulse facilitation. Hence, the observed phenomenon engaged similar mechanisms as classical LTP. This was a remarkable finding as theta-burst stimulation-induced LTP was equivalent between genotypes. Importantly, post-hypoxic LTP was generated in wild-type slices pretreated with system xc - inhibitor, S-4-carboxyphenylglycine, thereby confirming the antiporter's role in this phenomenon. Collectively, these data indicate that system xc - interference enables neuroplasticity in response to mild hypoxia, and, together with its regulation of cellular damage in the ischaemic core, suggest a role for the antiporter in post-ischaemic recovery of the penumbra.


Asunto(s)
Sistema de Transporte de Aminoácidos y+ , Hipocampo , Hipoxia , Potenciación a Largo Plazo , Ratones Noqueados , Animales , Potenciación a Largo Plazo/fisiología , Hipocampo/metabolismo , Ratones , Hipoxia/fisiopatología , Hipoxia/metabolismo , Sistema de Transporte de Aminoácidos y+/metabolismo , Masculino , Transmisión Sináptica/fisiología , Ratones Endogámicos C57BL , Ácido Glutámico/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
11.
Life Sci ; 355: 122988, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-39153595

RESUMEN

Major depressive disorder (MDD) is a form of glial cell-based synaptic dysfunction disease in which glial cells interact closely with neuronal synapses and perform synaptic information processing. Glial cells, particularly astrocytes, are active components of the brain and are responsible for synaptic activity through the release gliotransmitters. A reduced density of astrocytes and astrocyte dysfunction have both been identified the brains of patients with MDD. Furthermore, gliotransmission, i.e., active information transfer mediated by gliotransmitters between astrocytes and neurons, is thought to be involved in the pathogenesis of MDD. However, the mechanism by which astrocyte-mediated gliotransmission contributes to depression remains unknown. This review therefore summarizes the alterations in astrocytes in MDD, including astrocyte marker, connexin 43 (Cx43) expression, Cx43 gap junctions, and Cx43 hemichannels, and describes the regulatory mechanisms of astrocytes involved in synaptic plasticity. Additionally, we investigate the mechanisms acting of the glutamatergic, gamma-aminobutyric acidergic, and purinergic systems that modulate synaptic function and the antidepressant mechanisms of the related receptor antagonists. Further, we summarize the roles of glutamate, gamma-aminobutyric acid, d-serine, and adenosine triphosphate in depression, providing a basis for the identification of diagnostic and therapeutic targets for MDD.


Asunto(s)
Astrocitos , Conexina 43 , Trastorno Depresivo Mayor , Plasticidad Neuronal , Humanos , Astrocitos/metabolismo , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/fisiopatología , Plasticidad Neuronal/fisiología , Animales , Conexina 43/metabolismo , Transmisión Sináptica/fisiología , Ácido Glutámico/metabolismo , Neuroglía/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Sinapsis/metabolismo , Sinapsis/fisiología
12.
Nutrients ; 16(16)2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39203897

RESUMEN

γ-Aminobutyric acid (GABA) is a widely distributed non-protein amino acid that serves as a crucial inhibitory neurotransmitter in the brain, regulating various physiological functions. As a result of its potential benefits, GABA has gained substantial interest in the functional food and pharmaceutical industries. The enzyme responsible for GABA production is glutamic acid decarboxylase (GAD), which catalyzes the irreversible decarboxylation of glutamate. Understanding the crystal structure and catalytic mechanism of GAD is pivotal in advancing our knowledge of GABA production. This article provides an overview of GAD's sources, structure, and catalytic mechanism, and explores strategies for enhancing GABA production through fermentation optimization, metabolic engineering, and genetic engineering. Furthermore, the effects of GABA on the physiological functions of animal organisms are also discussed. To meet the increasing demand for GABA, various strategies have been investigated to enhance its production, including optimizing fermentation conditions to facilitate GAD activity. Additionally, metabolic engineering techniques have been employed to increase the availability of glutamate as a precursor for GABA biosynthesis. By fine-tuning fermentation conditions and utilizing metabolic and genetic engineering techniques, it is possible to achieve higher yields of GABA, thus opening up new avenues for its application in functional foods and pharmaceuticals. Continuous research in this field holds immense promise for harnessing the potential of GABA in addressing various health-related challenges.


Asunto(s)
Biotecnología , Fermentación , Glutamato Descarboxilasa , Ingeniería Metabólica , Ácido gamma-Aminobutírico , Ácido gamma-Aminobutírico/biosíntesis , Ácido gamma-Aminobutírico/metabolismo , Glutamato Descarboxilasa/metabolismo , Ingeniería Metabólica/métodos , Biotecnología/métodos , Animales , Humanos , Ingeniería Genética , Ácido Glutámico/metabolismo
13.
Adv Neurobiol ; 39: 233-267, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39190078

RESUMEN

The interactions between astrocytes and neurons in the context of stroke play crucial roles in the disease's progression and eventual outcomes. After a stroke, astrocytes undergo significant changes in their morphology, molecular profile, and function, together termed reactive astrogliosis. Many of these changes modulate how astrocytes relate to neurons, inducing mechanisms both beneficial and detrimental to stroke recovery. For example, excessive glutamate release and astrocytic malfunction contribute to excitotoxicity in stroke, eventually causing neuronal death. Astrocytes also provide essential metabolic support and neurotrophic signals to neurons after stroke, ensuring homeostatic stability and promoting neuronal survival. Furthermore, several astrocyte-secreted molecules regulate synaptic plasticity in response to stroke, allowing for the rewiring of neural circuits to compensate for damaged areas. In this chapter, we highlight the current understanding of the interactions between astrocytes and neurons in response to stroke, explaining the varied mechanisms contributing to injury progression and the potential implications for future therapeutic interventions.


Asunto(s)
Astrocitos , Plasticidad Neuronal , Neuronas , Accidente Cerebrovascular , Astrocitos/metabolismo , Humanos , Accidente Cerebrovascular/fisiopatología , Accidente Cerebrovascular/metabolismo , Neuronas/metabolismo , Plasticidad Neuronal/fisiología , Animales , Ácido Glutámico/metabolismo , Supervivencia Celular , Gliosis/metabolismo
14.
Neurotox Res ; 42(5): 39, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39190189

RESUMEN

There is a public health concern about the use of methylphenidate (MPH) since the higher prescription for young individuals and non-clinical purposes is addressed to the limited understanding of its neurochemical and psychiatric consequences. This study aimed to evaluate the impact of early and chronic MPH treatment on the striatum focusing on amino acid profile, glutamatergic excitotoxicity, redox status, neuroinflammation and glial cell responses. Male Wistar rats were treated with MPH (2.0 mg/kg) or saline solution from the 15th to the 44th postnatal day. Biochemical and histological analyses were conducted after the last administration. MPH altered the amino acid profile in the striatum, increasing glutamate and ornithine levels, while decreasing the levels of serine, phenylalanine, and branched-chain amino acids (leucine, valine, and isoleucine). Glutamate uptake and Na+,K+-ATPase activity were decreased in the striatum of MPH-treated rats as well as increased ATP levels, as indicator of glutamatergic excitotoxicity. Moreover, MPH caused lipid peroxidation and nitrative stress, increased TNF alpha expression, and induced high levels of astrocytes, and led to a decrease in BDNF levels. In summary, our results suggest that chronic early-age treatment with MPH induces parallel activation of damage-associated pathways in the striatum and increases its vulnerability during the juvenile period. In addition, data presented here contribute to shedding light on the mechanisms underlying MPH-induced striatal damage and its potential implications for neurodevelopmental disorders.


Asunto(s)
Aminoácidos , Astrocitos , Estimulantes del Sistema Nervioso Central , Cuerpo Estriado , Ácido Glutámico , Metilfenidato , Ratas Wistar , Animales , Masculino , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Metilfenidato/toxicidad , Metilfenidato/farmacología , Ácido Glutámico/metabolismo , Ratas , Estimulantes del Sistema Nervioso Central/toxicidad , Estimulantes del Sistema Nervioso Central/farmacología , Aminoácidos/metabolismo , Peroxidación de Lípido/efectos de los fármacos
15.
Sci Rep ; 14(1): 19678, 2024 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-39181891

RESUMEN

The formulation and delivery of macromolecules through the oral route pose considerable challenges due to factors such as large molecular weight, pH sensitivity, and limited formulation approaches. This challenge is compounded if the drug is poorly permeable, necessitating innovative drug delivery strategies. Vancomycin, a widely prescribed glycopeptide antibiotic, has an oral bioavailability of less than 10%, leading to predominantly intravenous administration and potential patient discomfort. This study explores the potential of the buccal route as a non-invasive, highly vascularised alternative route of administration, offering a rapid onset of action while bypassing the first-pass metabolism. In this study, vancomycin was coated with L-glutamic acid using an isothermal dry particle coater to modulate permeation through the buccal cell line, TR146. Results confirm significant impact of both amino acid concentration and dry particle coating on the rate and extent of drug permeability. With the introduction of L-glutamic acid and utilisation of the isothermal dry particle coater, vancomycin's permeation profile increased six-fold compared to the control due to the formation of drug ion-pair complex. Imaging studies showed the presence of layered micronized glutamic acid particles on the surface of dry coated vancomycin particles which confirms the role of dry coating and amino acid concentration in modulating drug permeation. Microbiology experiments in Staphylococcus aureus, minimum inhibitory concentration and biofilm disruption studies, provided confirmatory evidence of antimicrobial activity of dry coated glutamic acid-vancomycin ion pair particulate structure. This study demonstrates, for the first-time, buccal delivery of dry coated large molecule drug, vancomycin, through controlled deposition of amino acid using innovative particle coating strategy.


Asunto(s)
Antibacterianos , Vancomicina , Vancomicina/administración & dosificación , Vancomicina/farmacocinética , Humanos , Antibacterianos/administración & dosificación , Antibacterianos/farmacología , Antibacterianos/farmacocinética , Aminoácidos/química , Aminoácidos/metabolismo , Staphylococcus aureus/efectos de los fármacos , Mucosa Bucal/metabolismo , Permeabilidad/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos , Línea Celular , Ácido Glutámico/metabolismo
17.
PLoS One ; 19(8): e0308370, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39121049

RESUMEN

Human hyaluronidase 1 (HYAL1) and PH20 play vital roles in degrading hyaluronic acids through the substrate-assisted double displacement mechanism. While HYAL1, a lysosomal enzyme, functions optimally under acidic conditions, PH20, a sperm surface hyaluronidase, displays a broader pH range, from acidic to neutral. Our objective was to extend HYAL1's pH range towards neutral pH by introducing repulsive charge-charge interactions involving the catalytic Glu131, increasing its pKa as the proton donor. Substituting individual acidic residues in the ß3-loop (S77D), ß3'-ß3″ hairpin (T86D and P87E), and at Ala132 (A132D and A132E) enabled HYAL1 to demonstrate enzyme activity at pH 7, with the mutants S77D, P87E, and A132E showing the highest activity in the substrate gel assay. However, double and triple substitutions, including S77D/T86D/A132E as found in the PH20 configuration, did not result in enhanced activity compared to single substitutions. Conversely, PH20 mutants with non-acidic substitutions, such as D94S in the ß3-loop and D103T in the ß3'-ß3″ hairpin, significantly reduced activity within the pH range of 4 to 7. However, the PH20 mutant E149A, reciprocally substituted compared to A132E in HYAL1, exhibited activity similar to PH20 wild-type (WT) at pH 7. In a turbidimetric assay, HYAL1 mutants with single acidic substitutions exhibited activity similar to that of PH20 WT at pH 7. These results suggest that substituting acidic residues near Glu131 results in HYAL1 activity at neutral pH through electrostatic repulsion. This study highlights the significance of charge-charge interactions in both HYAL1 and PH20 in regulating the pH-dependent activity of hyaluronidases.


Asunto(s)
Hialuronoglucosaminidasa , Humanos , Sustitución de Aminoácidos , Dominio Catalítico , Moléculas de Adhesión Celular , Ácido Glutámico/metabolismo , Ácido Glutámico/química , Ácido Hialurónico/metabolismo , Ácido Hialurónico/química , Hialuronoglucosaminidasa/química , Hialuronoglucosaminidasa/metabolismo , Hialuronoglucosaminidasa/genética , Concentración de Iones de Hidrógeno , Modelos Moleculares , Mutación
18.
Cell Physiol Biochem ; 58(4): 431-444, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39215550

RESUMEN

BACKGROUND/AIMS: Over the years, the number of patients with neurodegenerative diseases is constantly rising illustrating the need for new neuroprotective drugs. A promising treatment approach is the reduction of excitotoxicity induced by rising (S)-glutamate levels and subsequent NMDA receptor overactivation. To facilitate the search for new NMDA receptor inhibitors neuronal cell models are needed. In this study, we evaluated the suitability of human SK-N-SH cells to serve as a cell model for neurodegeneration induced by NMDA receptor overstimulation. METHODS: The cytoprotective effect of the unselective NMDA receptor blocker ketamine as well as the GluN2B-selective inhibitor WMS14-10 was evaluated utilizing different cell viability assays, such as endpoint (LDH, CCK-8, DAPI/FACS) and time dependent methods (bioimpedance). RESULTS: Non-differentiated as well as differentiated SK-N-SH cells express GluN1 and GluN2B subunits. Furthermore, 50 mM (S)-glutamate led to an instantaneous decrease in cell survival. Only application of unselective channel blocker ketamine could protect differentiated cells against this effect, while the selective inhibitor WMS14-10 did not significantly increase cell survival. CONCLUSION: SK-N-SH cells show an increased sensitivity to (S)-glutamate mediated cytotoxicity with higher differentiation level, that is only partially induced by NMDA receptor overstimulation. Furthermore, we showed that only unselective NMDA receptor inhibition can partially reverse (S)-glutamate-induced toxicity.


Asunto(s)
Supervivencia Celular , Ácido Glutámico , Ketamina , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Humanos , Supervivencia Celular/efectos de los fármacos , Ketamina/farmacología , Línea Celular Tumoral , Ácido Glutámico/metabolismo , Ácido Glutámico/toxicidad , Diferenciación Celular/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/citología , Neuronas/patología , Proteínas del Tejido Nervioso
19.
J Neurosci ; 44(36)2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39134417

RESUMEN

Cognitive flexibility represents the capacity to switch among different mental schemes, providing an adaptive advantage to a changing environment. The neural underpinnings of this executive function have been deeply studied in humans through fMRI, showing that the left inferior frontal cortex (IFC) and the left inferior parietal lobule (IPL) are crucial. Here, we investigated the inhibitory-excitatory balance in these regions by means of γ-aminobutyric acid (GABA+) and glutamate + glutamine (Glx), measured with magnetic resonance spectroscopy, during a cognitive flexibility task and its relationship with the performance level and the local task-induced blood oxygenation level-dependent (BOLD) response in 40 young (18-35 years; 26 female) and 40 older (18-35 years; 21 female) human adults. As the IFC and the IPL are richly connected regions, we also examined whole-brain effects associated with their local metabolic activity. Results did not show absolute metabolic modulations associated with flexibility performance, but the performance level was related to the direction of metabolic modulation in the IPL with opposite patterns in young and older individuals. The individual inhibitory-excitatory balance modulation showed an inverse relationship with the local BOLD response in the IPL. Finally, the modulation of inhibitory-excitatory balance in IPL was related to whole-brain effects only in older individuals. These findings show disparities in the metabolic mechanisms underlying cognitive flexibility in young and older adults and their association with the performance level and BOLD response. Such metabolic differences are likely to play a role in executive functioning during aging and specifically in cognitive flexibility.


Asunto(s)
Envejecimiento , Cognición , Imagen por Resonancia Magnética , Humanos , Femenino , Masculino , Adulto , Adulto Joven , Adolescente , Cognición/fisiología , Envejecimiento/fisiología , Encéfalo/fisiología , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagen , Función Ejecutiva/fisiología , Mapeo Encefálico , Ácido gamma-Aminobutírico/metabolismo , Espectroscopía de Resonancia Magnética , Ácido Glutámico/metabolismo
20.
Redox Biol ; 75: 103278, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39128227

RESUMEN

The neuronal excitotoxicity that follows reoxygenation after a hypoxic period may contribute to epilepsy, Alzheimer's disease, Parkinson's disease and various disorders that are related to inadequate supplement of oxygen in neurons. Therefore, counteracting the deleterious effects of post-hypoxic stress is an interesting strategy to treat a large spectrum of neurodegenerative diseases. Here, we show that the expression of the key telomere protecting protein Trf2 decreases in the brain of mice submitted to a post-hypoxic stress. Moreover, downregulating the expression of Terf2 in hippocampal neural cells of unchallenged mice triggers an excitotoxicity-like phenotype including glutamate overexpression and behavioral alterations while overexpressing Terf2 in hippocampal neural cells of mice subjected to a post-hypoxic treatment prevents brain damages. Moreover, Terf2 overexpression in culture neurons counteracts the oxidative stress triggered by glutamate. Finally, we provide evidence that the effect of Terf2 downregulation on excitotoxicity involves Sirt3 repression leading to mitochondrial dysfunction. We propose that increasing the level of Terf2 expression is a potential strategy to reduce post-hypoxic stress damages.


Asunto(s)
Neuronas , Sirtuina 3 , Proteína 2 de Unión a Repeticiones Teloméricas , Animales , Ratones , Proteína 2 de Unión a Repeticiones Teloméricas/metabolismo , Proteína 2 de Unión a Repeticiones Teloméricas/genética , Sirtuina 3/metabolismo , Sirtuina 3/genética , Neuronas/metabolismo , Neuronas/patología , Hipocampo/metabolismo , Hipocampo/patología , Estrés Oxidativo , Mitocondrias/metabolismo , Encéfalo/metabolismo , Encéfalo/patología , Hipoxia/metabolismo , Ácido Glutámico/metabolismo , Telómero/metabolismo , Telómero/genética , Masculino
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