RESUMEN
Post-traumatic stress disorder (PTSD) presents distinct sex-specific differences in both symptom expression and treatment outcomes, with the underlying biological mechanisms still remain unclear. Epigenetic modifications, particularly histone acetylation, have been increasingly recognized as critical factors in the pathophysiology of PTSD. Valproic acid (VPA), a potent histone deacetylase (HDAC) inhibitor, has shown promise in modulating epigenetic responses and improving therapeutic outcomes is PTSD, though its effect may differ between sexes. This study aimed to explore the sex-specific epigenetic changes in response to trauma and the impact of VPA treatment in a rat model of PTSD induced by predator scent stress. Sprague-Dawley rats of both sexes were randomly assigned to stressed and non-stressed groups and treated with either VPA (100 mg/kg) or vehicle. Anxiety levels were assessed using the elevated plus maze, followed by analysis of histone H3 and H4 acetylation, HDAC activity, and c-fos expression in the hippocampus. Our findings revealed that traumatic stress led to increased freezing time and anxiety levels, with more pronounced effects observed in females. Additionally, we have identified sex-specific differences in hippocampal epigenetic modifications; stressed females exhibited higher H3 acetylation, and VPA-treated stressed males showed increased H4 acetylation. These results highlight the importance of considering sex differences in the epigenetic mechanism underlying PTSD and suggest that personalized therapeutic approaches may be necessary to address these complexities.
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Epigénesis Genética , Inhibidores de Histona Desacetilasas , Ratas Sprague-Dawley , Trastornos por Estrés Postraumático , Ácido Valproico , Animales , Ácido Valproico/farmacología , Trastornos por Estrés Postraumático/tratamiento farmacológico , Trastornos por Estrés Postraumático/genética , Trastornos por Estrés Postraumático/metabolismo , Masculino , Femenino , Epigénesis Genética/efectos de los fármacos , Ratas , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Modelos Animales de Enfermedad , Histonas/metabolismo , Caracteres Sexuales , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Acetilación/efectos de los fármacos , Ansiedad/tratamiento farmacológicoRESUMEN
Objective: To explore the effect of simulated gas of thermobaric bomb charge explosion on cognitive function and the related mechanism of damage. Methods: In January 2022, thirty-two SPF rats were selected and randomly divided into control group, exposed group 1, 2 and 3 (the exposure time of the simulated gas of the explosion of the thermobaric bomb charge was 5 min, 10 min and 15 min, respectively) according to random number table method, with 8 rats in each group. The simulated gas of the explosion of the thermobaric bomb charge were CO 0.15%, CO(2) 3%, NO 0.1%, O(2) 15%, and the rest were N(2). After 30 days of exposure, water maze was used to detect the learning and memory function of rats. Golgi staining was used to observe the number distribution and morphological structure of hippocampal neurons in rats. Western blot was used to detect the expression of Tau-5, pSer262, pSer396, pThr181 and pThr231 proteins in rats. Repeated measure ANOVA was used to compare the design data of repeated measure, one-way ANOVA was used for multi-group mean comparison, and LSD method was used for pound-wise comparison. Results: There were significant differences in the results of repeated measurement ANOVA of the water maze localization navigation test (F=80.98, P<0.001), and there was an interaction between the group and the training days (F=2.16, P=0.022). There were significant differences in escape latency of rats at the 2nd, 3rd, 4th and 5th days among all groups (P<0.05). The results of spatial exploration showed that the frequency of rats crossing the platform was significantly different among all groups (F=4.49, P=0.011). The frequency of rats crossing the platform in exposed group 2 and exposed group 3 was lower than that in control group, and the frequency of rats crossing the platform in exposed group 3 was lower than that in exposed group 1 (P<0.05). With the increase of exposure time, the number of hippocampal neurons decreased, and the dendrite spine density of neurons in CA1 region decreased (P<0.05). Compared with the control group, there was no significant difference in the relative expression level of Tau-5 protein in all exposed groups (P>0.05), but the expression level of pSer262 protein was significantly increased (P<0.05). Compared with the control group, the protein expressions of pSer396, pThr181 and pThr231 in exposed group 2 and exposed group 3 were significantly increased (P<0.05) . Conclusion: The simulated gas of the explosion of the thermobaric bomb charge may contribute to the development of cognitive dysfunction by damaging hippocampal neurons with aberrant phosphorylation of Tau proteins.
Asunto(s)
Cognición , Explosiones , Hipocampo , Aprendizaje por Laberinto , Proteínas tau , Animales , Masculino , Ratas , Traumatismos por Explosión/metabolismo , Hipocampo/metabolismo , Memoria , Neuronas/metabolismo , Fosforilación , Ratas Sprague-Dawley , Proteínas tau/metabolismoRESUMEN
BACKGROUND: Depression is often linked to inflammation in the brain. Researchers have been exploring ways to reduce this inflammation to improve depression symptoms. One potential target is a protein called RIPK1, which is known to contribute to brain inflammation. However, it's unclear how RIPK1 influences depression. Our study aims to determine whether RIPK1 inhibition could alleviate neuroinflammation-associated depression and elucidate its underlying mechanisms. METHODS: To investigate our research objectives, we established a neuroinflammation mouse model by administering LPS. Behavioral and biochemical assessments were conducted on these mice. The findings were subsequently validated through in vitro experiments. RESULTS: Using LPS-induced depression models, we investigated RIPK1's role, observing depressive-like behaviors accompanied by elevated cytokines, IBA-1, GFAP levels, and increased inflammatory signaling molecules and NO/H2O2. Remarkably, Necrostatin (Nec-1 S), a RIPK1 inhibitor, mitigated these changes. We further found altered expression and phosphorylation of eIF4E, PI3K/AKT/mTOR, and synaptic proteins in hippocampal tissues, BV2, and N2a cells post-LPS treatment, which Nec-1 S also ameliorated. Importantly, eIF4E inhibition reversed some of the beneficial effects of Nec-1 S, suggesting a complex interaction between RIPK1 and eIF4E in LPS-induced neuroinflammation. Moreover, citronellol, a RIPK1 agonist, significantly altered eIF4E phosphorylation, indicating RIPK1's potential upstream regulatory role in eIF4E and its contribution to neuroinflammation-associated depression. CONCLUSION: These findings propose RIPK1 as a pivotal mediator in regulating neuroinflammation and neural plasticity, highlighting its significance as a potential therapeutic target for depression.
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Depresión , Modelos Animales de Enfermedad , Lipopolisacáridos , Enfermedades Neuroinflamatorias , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Animales , Masculino , Ratones , Conducta Animal/efectos de los fármacos , Depresión/tratamiento farmacológico , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Hipocampo/patología , Imidazoles/farmacología , Imidazoles/uso terapéutico , Indoles/farmacología , Indoles/uso terapéutico , Inflamación/tratamiento farmacológico , Inflamación/patología , Lipopolisacáridos/farmacología , Ratones Endogámicos C57BL , Enfermedades Neuroinflamatorias/tratamiento farmacológico , Enfermedades Neuroinflamatorias/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Gene expression and alternative splicing are strictly regulated processes that shape brain development and determine the cellular identity of differentiated neural cell populations. Despite the availability of multiple valuable datasets, many functional implications, especially those related to alternative splicing, remain poorly understood. Moreover, neuroscientists working primarily experimentally often lack the bioinformatics expertise required to process alternative splicing data and produce meaningful and interpretable results. Notably, re-analyzing publicly available datasets and integrating them with in-house data can provide substantial novel insights. However, such analyses necessitate developing harmonized data handling and processing pipelines which in turn require considerable computational resources and in-depth bioinformatics expertise. RESULTS: Here, we present Cortexa-a comprehensive web portal that incorporates RNA-sequencing datasets from the mouse cerebral cortex (longitudinal or cell-specific) and the hippocampus. Cortexa facilitates understandable visualization of the expression and alternative splicing patterns of individual genes. Our platform provides SplicePCA-a tool that allows users to integrate their alternative splicing dataset and compare it to cell-specific or developmental neocortical splicing patterns. All standardized gene expression and alternative splicing datasets can be downloaded for further in-depth downstream analysis without the need for extensive preprocessing. CONCLUSIONS: Cortexa provides a robust and readily available resource for unraveling the complexity of gene expression and alternative splicing regulatory processes in the mouse brain. The data portal is available at https://cortexa-rna.com/.
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Empalme Alternativo , Encéfalo , Animales , Empalme Alternativo/genética , Ratones , Encéfalo/metabolismo , Biología Computacional/métodos , Programas Informáticos , Bases de Datos Genéticas , Análisis de Secuencia de ARN/métodos , Corteza Cerebral/metabolismo , Hipocampo/metabolismo , Perfilación de la Expresión Génica/métodosRESUMEN
AIMS: Type 2 diabetes mellitus (T2DM) is related to an increased risk of postoperative cognitive dysfunction (POCD), which may be caused by neuronal hyperexcitability. Astrocyte glutamate transporter 1 (GLT-1) plays a crucial role in regulating neuron excitability. We investigated if T2DM would magnify the increased neuronal excitability induced by anesthesia/surgery (A/S) and lead to POCD in young adult mice, and if so, determined whether these effects were associated with GLT-1 expression. METHODS: T2DM model was induced by high fat diet (HFD) and injecting STZ. Then, we evaluated the spatial learning and memory of T2DM mice after A/S with the novel object recognition test (NORT) and object location test (OLT). Western blotting and immunofluorescence were used to analyze the expression levels of GLT-1 and neuronal excitability. Oxidative stress reaction and neuronal apoptosis were detected with SOD2 expression, MMP level, and Tunel staining. Hippocampal functional synaptic plasticity was assessed with long-term potentiation (LTP). In the intervention study, we overexpressed hippocampal astrocyte GLT-1 in GFAP-Cre mice. Besides, AAV-Camkllα-hM4Di-mCherry was injected to inhibit neuronal hyperexcitability in CA1 region. RESULTS: Our study found T2DM but not A/S reduced GLT-1 expression in hippocampal astrocytes. Interestingly, GLT-1 deficiency alone couldn't lead to cognitive decline, but the downregulation of GLT-1 in T2DM mice obviously enhanced increased hippocampal glutamatergic neuron excitability induced by A/S. The hyperexcitability caused neuronal apoptosis and cognitive impairment. Overexpression of GLT-1 rescued postoperative cognitive dysfunction, glutamatergic neuron hyperexcitability, oxidative stress reaction, and apoptosis in hippocampus. Moreover, chemogenetic inhibition of hippocampal glutamatergic neurons reduced oxidative stress and apoptosis and alleviated postoperative cognitive dysfunction. CONCLUSIONS: These findings suggest that the adult mice with type 2 diabetes are at an increased risk of developing POCD, perhaps due to the downregulation of GLT-1 in hippocampal astrocytes, which enhances increased glutamatergic neuron excitability induced by A/S and leads to oxidative stress reaction, and neuronal apoptosis.
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Astrocitos , Diabetes Mellitus Tipo 2 , Regulación hacia Abajo , Transportador 2 de Aminoácidos Excitadores , Hipocampo , Ratones Endogámicos C57BL , Complicaciones Cognitivas Postoperatorias , Animales , Transportador 2 de Aminoácidos Excitadores/metabolismo , Transportador 2 de Aminoácidos Excitadores/biosíntesis , Transportador 2 de Aminoácidos Excitadores/genética , Astrocitos/metabolismo , Complicaciones Cognitivas Postoperatorias/etiología , Complicaciones Cognitivas Postoperatorias/metabolismo , Hipocampo/metabolismo , Ratones , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones TransgénicosRESUMEN
BACKGROUND: Alzheimer's disease (AD) features progressive neurodegeneration and microglial activation that results in dementia and cognitive decline. The release of soluble amyloid (Aß) oligomers into the extracellular space is an early feature of AD pathology. This can promote excitotoxicity and microglial activation. Microglia can adopt several activation states with various functional outcomes. Protective microglial activation states have been identified in response to Aß plaque pathology in vivo. However, the role of microglia and immune mediators in neurotoxicity induced by soluble Aß oligomers is unclear. Further, there remains a need to identify druggable molecular targets that promote protective microglial states to slow or prevent the progression of AD. METHODS: Hippocampal entorhinal brain slice culture (HEBSC) was employed to study mechanisms of Aß1-42 oligomer-induced neurotoxicity as well as the role of microglia. The roles of glutamate hyperexcitation and immune signaling in Aß-induced neurotoxicity were assessed using MK801 and neutralizing antibodies to the TNF-related apoptosis-inducing ligand (TRAIL) respectively. Microglial activation state was manipulated using Gi-hM4di designer receptor exclusively activated by designer drugs (DREADDs), microglial depletion with the colony-stimulating factor 1 receptor (CSF1R) antagonist PLX3397, and microglial repopulation (PLX3397 withdrawal). Proteomic changes were assessed by LC-MS/MS in microglia isolated from control, repopulated, or Aß-treated HEBSCs. RESULTS: Neurotoxicity induced by soluble Aß1-42 oligomers involves glutamatergic hyperexcitation caused by the proinflammatory mediator and death receptor ligand TRAIL. Microglia were found to have the ability to both promote and restrain Aß-induced toxicity. Induction of microglial Gi-signaling with hM4di to prevent pro-inflammatory activation blunted Aß neurotoxicity, while microglial depletion with CSF1R antagonism worsened neurotoxicity caused by Aß as well as TRAIL. HEBSCs with repopulated microglia, however, showed a near complete resistance to Aß-induced neurotoxicity. Comparison of microglial proteomes revealed that repopulated microglia have a baseline anti-inflammatory and trophic phenotype with a predicted pathway activation that is nearly opposite that of Aß-exposed microglia. mTORC2 and IRF7 were identified as potential targets for intervention. CONCLUSION: Microglia are key mediators of both protection and neurodegeneration in response to Aß. Polarizing microglia toward a protective state could be used as a preventative strategy against Aß-induced neurotoxicity.
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Péptidos beta-Amiloides , Microglía , Fragmentos de Péptidos , Ligando Inductor de Apoptosis Relacionado con TNF , Microglía/metabolismo , Microglía/efectos de los fármacos , Péptidos beta-Amiloides/toxicidad , Péptidos beta-Amiloides/metabolismo , Animales , Fragmentos de Péptidos/toxicidad , Fragmentos de Péptidos/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/metabolismo , Ligando Inductor de Apoptosis Relacionado con TNF/toxicidad , Ratones , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Ratones Endogámicos C57BL , Corteza Entorrinal/metabolismo , Corteza Entorrinal/efectos de los fármacos , Corteza Entorrinal/patología , Técnicas de Cultivo de ÓrganosRESUMEN
The L-type Ca2+ channel (LTCC, also known as Cav1,2) is involved in the regulation of key neuronal functions, such as dendritic information integration, cell survival, and neuronal gene expression. Clinical studies have shown an association between L-type calcium channels and the onset of depression, although the precise mechanisms remain unclear. The development of depression results from a combination of environmental and genetic factors. DNA methylation, a significant epigenetic modification, plays a regulatory role in the pathogenesis of psychiatric disorders such as posttraumatic stress disorder (PTSD), depression, and autism. In our study, we observed reduced Dnmt3a expression levels in the hippocampal DG region of mice with LPS-induced depression compared to control mice. The antidepressant Venlafaxine was able to increase Dnmt3a expression levels. Conversely, Bay K 8644, an agonist of the L-type Ca2+ channel, partially ameliorated depression-like behaviors but did not elevate Dnmt3a expression levels. Furthermore, when we manipulated DNA methylation levels during Bay K 8644 intervention in depression-like models, we found that enhancing the expression of Dnmt3a could improve LPS-induced depression/anxiety-like behaviors, while inhibiting DNA methylation exacerbated anxiety-like behaviors, the combined use of BAY K 8644 and L-methionine can better improve depressive-like behavior. These findings indicate that DNA methylation plays a role in the regulation of depression-like behaviors by the L-type Ca2+ channel, and further research is needed to elucidate the interactions between DNA methylation and L-type Ca2+ channels.
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Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico , Agonistas de los Canales de Calcio , Canales de Calcio Tipo L , Metilación de ADN , ADN Metiltransferasa 3A , Depresión , Metionina , Animales , Canales de Calcio Tipo L/metabolismo , Canales de Calcio Tipo L/efectos de los fármacos , Metionina/farmacología , Masculino , Depresión/tratamiento farmacológico , Depresión/metabolismo , Ratones , Agonistas de los Canales de Calcio/farmacología , Metilación de ADN/efectos de los fármacos , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Ratones Endogámicos C57BL , Antidepresivos/farmacología , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Lipopolisacáridos/farmacología , Modelos Animales de EnfermedadRESUMEN
After seizures, the hyperactivation of extracellular signal-regulated kinases (ERK1/2) causes mitochondrial dysfunction. Through the guidance of dynamin-related protein 1 (DRP1), ERK1/2 plays a role in the pathogenesis of several illnesses. Herein, we speculate that ERK1/2 affects mitochondrial division and participates in the pathogenesis of epilepsy by regulating the activity of DRP1. LiCl-Pilocarpine was injected intraperitoneally to establish a rat model of status epilepticus (SE) for this study. Before SE induction, PD98059 and Mdivi-1 were injected intraperitoneally. The number of seizures and the latency period before the onset of the first seizure were then monitored. The analysis of Western blot was also used to measure the phosphorylated and total ERK1/2 and DRP1 protein expression levels in the rat hippocampus. In addition, immunohistochemistry revealed the distribution of ERK1/2 and DRP1 in neurons of hippocampal CA1 and CA3. Both PD98059 and Mdivi-1 reduced the susceptibility of rats to epileptic seizures, according to behavioral findings. By inhibiting ERK1/2 phosphorylation, the Western blot revealed that PD98059 indirectly reduced the phosphorylation of DRP1 at Ser616 (p-DRP1-Ser616). Eventually, the ERK1/2 and DRP1 were distributed in the cytoplasm of neurons by immunohistochemistry. Inhibition of ERK1/2 signaling pathways downregulates p-DRP1-Ser616 expression, which could inhibit DRP1-mediated excessive mitochondrial fission and then regulate the pathogenesis of epilepsy.
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Dinaminas , Flavonoides , Dinámicas Mitocondriales , Pilocarpina , Quinazolinonas , Ratas Sprague-Dawley , Estado Epiléptico , Animales , Dinaminas/metabolismo , Dinaminas/genética , Dinámicas Mitocondriales/fisiología , Dinámicas Mitocondriales/efectos de los fármacos , Masculino , Pilocarpina/toxicidad , Estado Epiléptico/metabolismo , Estado Epiléptico/inducido químicamente , Flavonoides/farmacología , Quinazolinonas/farmacología , Sistema de Señalización de MAP Quinasas/fisiología , Ratas , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Convulsiones/metabolismo , Cloruro de Litio/farmacología , Modelos Animales de Enfermedad , Neuronas/metabolismo , Neuronas/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , FosforilaciónRESUMEN
Kruppel-like factor 4 (Klf4) is a transcription factor that is involved in neuronal regeneration and the development of glutamatergic systems. However, it is unknown whether Klf4 is involved in acute seizure. To investigate the potential role of Klf4 in pentylenetetrazol (PTZ)-induced seizure, western blotting, immunofluorescence, behaviour test and electrophysiology were conducted in this study. We found that Klf4 protein and mRNA expression were increased in both the hippocampus (HP) and prefrontal cortex (PFC) after PTZ-induced seizure in mice. HP-specific knockout (KO) of Klf4 in mice decreased protein expression of Klf4 and the down-stream Klf4 target tumour protein 53 (TP53/P53). These molecular changes are accompanied by increased seizure latency, reduced immobility time in the forced swimming test and tail suspension test. Reduced hippocampal protein levels for synaptic proteins, including glutamate receptor 1 (GRIA1/GLUA1) and postsynaptic density protein 95 (DLG4/PSD95), were also observed after Klf4-KO, while increased mRNA levels of complement proteins were observed for complement component 1q subcomponent A (C1qa), complement component 1q subcomponent B (C1qb), complement component 1q subcomponent C (C1qc), complement component 3 (C3), complement component 4A (C4a) and complement component 4B (C4b). Moreover, c-Fos expression induced by PTZ was reduced by hippocampal conditional KO of Klf4. Electrophysiology showed that PTZ-induced action potential frequency was decreased by overexpression of Klf4. In conclusion, these findings suggest that Klf4 plays an important role in regulating PTZ-induced seizures and therefore constitutes a new molecular target that should be explored for the development of antiepileptic drugs.
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Hipocampo , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel , Ratones Noqueados , Pentilenotetrazol , Convulsiones , Animales , Factor 4 Similar a Kruppel/metabolismo , Convulsiones/metabolismo , Convulsiones/inducido químicamente , Convulsiones/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Ratones , Hipocampo/metabolismo , Masculino , Corteza Prefrontal/metabolismo , Ratones Endogámicos C57BL , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Major depressive disorder (MDD) is characterized by hippocampal volume reduction, impacting cognitive function. Inflammation, particularly elevated tumor necrosis factor-alpha (TNF-α) levels, is consistently implicated in MDD pathophysiology. This study investigates the relationships between TNF-α levels, hippocampal volume, beta-amyloid (Aß) burden, and cognitive abilities in MDD patients, aiming to illuminate the complex interplay among inflammatory markers, pathology indicators, structural brain alterations, and cognitive performance in non-demented MDD individuals. METHOD: Fifty-two non-demented MDD patients, comprising 25 with mild cognitive impairment (MCI), were recruited along with 10 control subjects. Each participant underwent a thorough assessment encompassing TNF-α blood testing, 18F-florbetapir positron emission tomography, magnetic resonance imaging scans, and neuropsychological testing. Statistical analyses, adjusted for age and education, were performed to investigate the associations between TNF-α levels, adjusted hippocampal volume (HVa), global Aß burden, and cognitive performance. RESULTS: MCI MDD patients displayed elevated TNF-α levels and reduced HVa relative to controls. Correlation analyses demonstrated inverse relationships between TNF-α level and HVa in MCI MDD, all MDD, and all subjects groups. Both TNF-α level and HVa exhibited significant correlations with processing speed across all MDD and all subjects. Notably, global 18F-florbetapir standardized uptake value ratio did not exhibit significant correlations with TNF-α level, HVa, and cognitive measures. CONCLUSION: This study highlights elevated TNF-α levels and reduced hippocampal volume in MCI MDD patients, indicating a potential association between peripheral inflammation and structural brain alterations in depression. Furthermore, our results suggest that certain cases of MDD may be affected by non-amyloid-mediated process, which impacts their TNF-α and hippocampal volume. These findings emphasize the importance of further investigating the complex interplay among inflammation, neurodegeneration, and cognitive function in MDD.
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Péptidos beta-Amiloides , Atrofia , Disfunción Cognitiva , Trastorno Depresivo Mayor , Hipocampo , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Factor de Necrosis Tumoral alfa , Humanos , Trastorno Depresivo Mayor/diagnóstico por imagen , Trastorno Depresivo Mayor/metabolismo , Trastorno Depresivo Mayor/patología , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Hipocampo/metabolismo , Masculino , Femenino , Factor de Necrosis Tumoral alfa/metabolismo , Factor de Necrosis Tumoral alfa/sangre , Anciano , Péptidos beta-Amiloides/metabolismo , Atrofia/patología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/metabolismo , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/diagnóstico por imagen , Persona de Mediana Edad , Pruebas Neuropsicológicas , Compuestos de Anilina , Glicoles de EtilenoRESUMEN
Autism spectrum disorders (ASD) are complex neurodevelopmental conditions characterized by impairments in social communication, repetitive behaviors, and restricted interests. Epigenetic modifications serve as critical regulators of gene expression playing a crucial role in controlling brain function and behavior. Lysine (K)-specific demethylase 6B (KDM6B), a stress-inducible H3K27me3 demethylase, has emerged as one of the highest ASD risk genes, but the precise effects of KDM6B mutations on neuronal activity and behavioral function remain elusive. Here we show the impact of KDM6B mosaic brain knockout on the manifestation of different autistic-like phenotypes including repetitive behaviors, social interaction, and significant cognitive deficits. Moreover, KDM6B mosaic knockout display abnormalities in hippocampal excitatory synaptic transmission decreasing NMDA receptor mediated synaptic transmission and plasticity. Understanding the intricate interplay between epigenetic modifications and neuronal function may provide novel insights into the pathophysiology of ASD and potentially inform the development of targeted therapeutic interventions.
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Trastorno del Espectro Autista , Histona Demetilasas con Dominio de Jumonji , Ratones Noqueados , Transmisión Sináptica , Animales , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Transmisión Sináptica/genética , Trastorno del Espectro Autista/genética , Ratones , Encéfalo/metabolismo , Plasticidad Neuronal/genética , Conducta Animal , Hipocampo/metabolismo , Epigénesis Genética , Masculino , Sinapsis/metabolismoRESUMEN
The therapeutic potential of suppressing polypyrimidine tract-binding protein 1 (Ptbp1) messenger RNA by viral transduction in a post-stroke dementia mouse model has not yet been examined. In this study, 3 days after cerebral ischemia, we injected a viral vector cocktail containing adeno-associated virus (AAV)-pGFAP-mCherry and AAV-pGFAP-CasRx (control vector) or a cocktail of AAV-pGFAP-mCherry and AAV-pGFAP-CasRx-SgRNA-(Ptbp1) (1:5, 1.0 × 1011 viral genomes) into post-stroke mice via the tail vein. We observed new mCherry/NeuN double-positive neuron-like cells in the hippocampus 56 days after cerebral ischemia. A portion of mCherry/GFAP double-positive astrocyte-like glia could have been converted into new mCherry/NeuN double-positive neuron-like cells with morphological changes. The new neuronal cells integrated into the dentate gyrus and recognition memory was significantly ameliorated. These results demonstrated that the in vivo conversion of hippocampal astrocyte-like glia into functional new neurons by the suppression of Ptbp1 might be a therapeutic strategy for post-stroke dementia.
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Astrocitos , Isquemia Encefálica , Modelos Animales de Enfermedad , Ribonucleoproteínas Nucleares Heterogéneas , Hipocampo , Neurogénesis , Proteína de Unión al Tracto de Polipirimidina , Animales , Proteína de Unión al Tracto de Polipirimidina/metabolismo , Proteína de Unión al Tracto de Polipirimidina/genética , Astrocitos/metabolismo , Hipocampo/metabolismo , Hipocampo/patología , Ratones , Isquemia Encefálica/metabolismo , Isquemia Encefálica/terapia , Ribonucleoproteínas Nucleares Heterogéneas/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas/genética , Masculino , Neuronas/metabolismo , Memoria , Ratones Endogámicos C57BL , Vectores Genéticos/genética , Vectores Genéticos/administración & dosificaciónRESUMEN
BACKGROUND: Reduction of adult hippocampal neurogenesis is an early critical event in Alzheimer's disease (AD), contributing to progressive memory loss and cognitive decline. Reduced levels of the nucleoporin 153 (Nup153), a key epigenetic regulator of NSC stemness, characterize the neural stem cells isolated from a mouse model of AD (3×Tg) (AD-NSCs) and determine their altered plasticity and gene expression. METHODS: Nup153-regulated mechanisms contributing to NSC function were investigated: (1) in cultured NSCs isolated from AD and wild type (WT) mice by proteomics; (2) in vivo by lentiviral-mediated delivery of Nup153 or GFP in the hippocampus of AD and control mice analyzing neurogenesis and cognitive function; (3) in human iPSC-derived brain organoids obtained from AD patients and control subjects as a model of neurodevelopment. RESULTS: Proteomic approach identified Nup153 interactors in WT- and AD-NSCs potentially implicated in neurogenesis regulation. Gene ontology (GO) analysis showed that Nup153-bound proteins in WT-NSCs were involved in RNA metabolism, nuclear import and epigenetic mechanisms. Nup153-bound proteins in AD-NSCs were involved in pathways of neurodegeneration, mitochondrial dysfunction, proteasomal processing and RNA degradation. Furthermore, recovery of Nup153 levels in AD-NSCs reduced the levels of oxidative stress markers and recovered proteasomal activity. Lentiviral-mediated delivery of Nup153 in the hippocampal niche of AD mice increased the proliferation of early progenitors, marked by BrdU/DCX and BrdU/PSANCAM positivity and, later, the integration of differentiating neurons in the cell granule layer (BrdU/NeuN+ cells) compared with GFP-injected AD mice. Consistently, Nup153-injected AD mice showed an improvement of cognitive performance in comparison to AD-GFP mice at 1 month after virus delivery assessed by Morris Water Maze. To validate the role of Nup153 in neurogenesis we took advantage of brain organoids derived from AD-iPSCs characterized by fewer neuroepithelial progenitor loops and reduced differentiation areas. The upregulation of Nup153 in AD organoids recovered the formation of neural-like tubes and differentiation. CONCLUSIONS: Our data suggest that the positive effect of Nup153 on neurogenesis is based on a complex regulatory network orchestrated by Nup153 and that this protein is a valuable disease target.
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Enfermedad de Alzheimer , Modelos Animales de Enfermedad , Células-Madre Neurales , Neurogénesis , Proteínas de Complejo Poro Nuclear , Animales , Proteínas de Complejo Poro Nuclear/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Ratones , Células-Madre Neurales/metabolismo , Células-Madre Neurales/citología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Humanos , Hipocampo/metabolismo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , ProteómicaRESUMEN
BACKGROUND: Sepsis-associated encephalopathy (SAE) is a neuronal injury with poor prognosis. Mitochondrial dysfunction is critical in SAE development, and hydrogen gas (H2) has a protective effect on septic mice. This study aimed to investigate the effect of high concentration (67%) of H2 on SAE and whether it is related to mitochondrial biogenesis and mitochondrial dynamics. METHODS: A mouse sepsis model was induced by cecal ligation and puncture. The mice inhalated 67% H2 for 1 h at 1 and 6 h post-surgery, respectively. The 7-day survival rate was recorded. Cognitive function was assessed using the Y-maze test and Morris water maze test. Serum inflammatory factors, antioxidant enzymes, as well as mitochondrial function indexes including mitochondrial membrane potential (MMP) and ATP in the hippocampal tissue were evaluated 24 h after surgery. Mitochondrial dynamic proteins (DRP1 and MFN2) and biosynthetic proteins (PGC-1α, NRF2, and TFAM) in the hippocampal tissue were detected. Moreover, the morphology of mitochondria was observed by transmission electron microscopy. RESULTS: Inhalation of 67% H2 improved the 7-day survival rates and recognition memory function of septic mice, alleviated brain antioxidant enzyme activity (SOD and CAT), and reduced serum proinflammatory cytokine levels. H2 inhalation also enhanced the expression of MFN2 and mitochondrial biogenesis-related factors (PGC-1α, NRF2, and TFAM) and decreased the expression of fission protein (DRP1), leading to improvement in mitochondrial function, as evidenced by MMP and ATP levels. CONCLUSIONS: Inhalation of high concentration (67%) of H2 in septic mice improved the survival rate and reduced neuronal injury. Its mechanism might be mediated by enhancing mitochondrial biogenesis and mitochondrial dynamics.
Asunto(s)
Hidrógeno , Dinámicas Mitocondriales , Encefalopatía Asociada a la Sepsis , Animales , Encefalopatía Asociada a la Sepsis/tratamiento farmacológico , Ratones , Hidrógeno/farmacología , Hidrógeno/administración & dosificación , Hidrógeno/uso terapéutico , Dinámicas Mitocondriales/efectos de los fármacos , Masculino , Administración por Inhalación , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Sepsis/complicaciones , Sepsis/tratamiento farmacológico , Sepsis/metabolismo , Ratones Endogámicos C57BL , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Aprendizaje por Laberinto/efectos de los fármacosRESUMEN
Penicillium daleae L3SO is a fungus isolated from the rhizospheric soil of the chloroplast-deficient plant Monotropa uniflora. A chemical study on the rice fermentation of this fungus led to the isolation and identification of two cage-like polyketides, penidaleodiolide A (1) and its biosynthetic-related congener penidaleodiolide B (2). The structures of 1 and 2 were determined by a combination of extensive spectroscopic analysis, biosynthetic consideration, chemical derivatization, and computational methods. Compound 1 harbors an unusual tricyclo[4.3.04,9]nonane scaffold, unprecedented in polyketide natural products. The hypothetical biosynthetic pathways for 1 and 2 were postulated and were supported by CRISPR/Cas9 genome editing results. Penidaleodiolide A (1) showed a significant inhibitory effect on the action potentials of murine hippocampal basket neurons and decreased the frequency of spontaneous excitatory postsynaptic currents in a concentration-dependent manner (the inhibition ratios were 0.30 ± 0.02 for 1 µM, 0.37 ± 0.03 for 10 µM, and 0.50 ± 0.07 for 20 µM) while being devoid of cytotoxicity against the nerve cells.
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Penicillium , Policétidos , Policétidos/química , Policétidos/farmacología , Policétidos/aislamiento & purificación , Penicillium/química , Penicillium/metabolismo , Animales , Ratones , Estructura Molecular , Transmisión Sináptica/efectos de los fármacos , Microbiología del Suelo , Neuronas/efectos de los fármacos , Hipocampo/metabolismoRESUMEN
Sensory experiences and learning induce long-lasting changes in both excitatory and inhibitory synapses, thereby providing a crucial substrate for memory. However, the co-tuning of excitatory long-term potentiation (eLTP) or depression (eLTD) with the simultaneous changes at inhibitory synapses (iLTP/iLTD) remains unclear. Herein, we investigated the co-expression of NMDA-induced synaptic plasticity at excitatory and inhibitory synapses in hippocampal CA1 pyramidal cells (PCs) using a combination of electrophysiological, optogenetic, and pharmacological approaches. We found that inhibitory inputs from somatostatin (SST) and parvalbumin (PV)-positive interneurons onto CA1 PCs display input-specific long-term plastic changes following transient NMDA receptor activation. Notably, synapses from SST-positive interneurons consistently exhibited iLTP, irrespective of the direction of excitatory plasticity, whereas synapses from PV-positive interneurons predominantly showed iLTP concurrent with eLTP, rather than eLTD. As neuroplasticity is known to depend on the extracellular matrix, we tested the impact of metalloproteinases (MMP) inhibition. MMP3 blockade interfered with GABAergic plasticity for all inhibitory inputs, whereas MMP9 inhibition selectively blocked eLTP and iLTP in SST-CA1PC synapses co-occurring with eLTP but not eLTD. These findings demonstrate the dissociation of excitatory and inhibitory plasticity co-expression. We propose that these mechanisms of plasticity co-expression may be involved in maintaining excitation-inhibition balance and modulating neuronal integration modes.
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Interneuronas , Plasticidad Neuronal , Células Piramidales , Animales , Plasticidad Neuronal/fisiología , Interneuronas/metabolismo , Células Piramidales/metabolismo , Células Piramidales/fisiología , N-Metilaspartato/metabolismo , N-Metilaspartato/farmacología , Hipocampo/metabolismo , Hipocampo/fisiología , Parvalbúminas/metabolismo , Masculino , Ratones , Somatostatina/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapsis/metabolismo , Sinapsis/fisiología , Potenciación a Largo Plazo , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/efectos de los fármacos , Región CA1 Hipocampal/metabolismo , Región CA1 Hipocampal/fisiología , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genéticaRESUMEN
BACKGROUND: Previous studies have indicated that occlusal disharmony (OD) can promote anxiety-like behaviours. However, the specific molecules involved in the development of anxiety-like behaviours and their underlying mechanisms remain unknown. METHODS: OD was produced by anterior crossbite of female mice. We measured the anxiety levels of mice in each group and screened the hippocampal mRNA expression profiles of mice in the control group and OD group. The role of target mRNA in OD-induced anxiety-like behaviours was evaluated and we preliminarily explored the possible downstream pathways. RESULTS: The results suggested that OD can induce and promote anxiety-like behaviours with/without chronic unpredictable mild stress. We found that Sirt1 was significantly downregulated within the hippocampus in OD mice. In addition, the downregulation of Sirt1 within the hippocampus in OD and control mice promoted anxiety-like behaviours, increased acetylated histone H3 expression and decreased Dnah12 transcription levels. In contrast, in OD mice subjected to an injection of resveratrol, there was a remission of anxiety-like behaviours and an upregulation of Sirt1 in the hippocampus, the effects of which were accompanied by decreased acetylated histone H3 expression and increased Dnah12 transcription levels. CONCLUSIONS: OD leads to increased sensitivity to chronic stress in mice, resulting in anxiety-like behaviours. During this process, Sirt1 acts as an effective factor in the regulation of OD-induced anxiety-like behaviours. CLINICAL RELEVANCE: OD, as a stressor, could induce anxiety-like behaviours. It investigates the impact of OD (a stressor) on the molecular genetic of the pathophysiology of major neuropsychiatric disorders.
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Ansiedad , Conducta Animal , Modelos Animales de Enfermedad , Sirtuina 1 , Animales , Sirtuina 1/metabolismo , Ratones , Femenino , Maloclusión , Hipocampo/metabolismo , Resveratrol/farmacología , Regulación hacia Abajo , ARN Mensajero/metabolismoRESUMEN
The generation of new neurons at the hippocampal neurogenic niche, known as adult hippocampal neurogenesis (AHN), and its impairment, have been implicated in Alzheimer's disease (AD). MicroRNA-132 (miR-132), the most consistently downregulated microRNA (miRNA) in AD, was recently identified as a potent regulator of AHN, exerting multilayered proneurogenic effects in adult neural stem cells (NSCs) and their progeny. Supplementing miR-132 in AD mouse brain restores AHN and relevant memory deficits, yet the exact mechanisms involved are still unknown. Here, we identify NACC2 as a novel miR-132 target implicated in both AHN and AD. miR-132 deficiency in mouse hippocampus induces Nacc2 expression and inflammatory signaling in adult NSCs. We show that miR-132-dependent regulation of NACC2 is involved in the initial stages of human NSC differentiation towards astrocytes and neurons. Later, NACC2 function in astrocytic maturation becomes uncoupled from miR-132. We demonstrate that NACC2 is present in reactive astrocytes surrounding amyloid plaques in mouse and human AD hippocampus, and that there is an anticorrelation between miR-132 and NACC2 levels in AD and upon induction of inflammation. Unraveling the molecular mechanisms by which miR-132 regulates neurogenesis and cellular reactivity in AD, will provide valuable insights towards its possible application as a therapeutic target.
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Enfermedad de Alzheimer , Astrocitos , Hipocampo , MicroARNs , Células-Madre Neurales , Neurogénesis , MicroARNs/genética , MicroARNs/metabolismo , Neurogénesis/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Animales , Humanos , Células-Madre Neurales/metabolismo , Ratones , Hipocampo/metabolismo , Hipocampo/patología , Astrocitos/metabolismo , Neuronas/metabolismo , Diferenciación Celular , Regulación de la Expresión GénicaRESUMEN
Epidemiological, experimental, and ecological data have indicated the controversial effect of in utero chronic low dose rate (<6 mGy/h) with accumulative low (≤100 mGy) or high (>100 mGy) dose radiation exposure. Our main goal of this study was to examine if different low dose rates of chronic pre- and/or post-natal radiation exposure with accumulative high doses could induce hippocampal cellular, mRNA, and miRNA changes leading to neuropsychiatric disorders. The comprehensive mouse phenotypic traits, organ weight, pathological, and blood mRNA and miRNA changes were also studied. Using different approaches including SmithKline, Harwell, Imperial College, Royal Hospital, Phenotype Assessment (SHIRPA), neurobehavioral tests, pathological examination, immunohistochemistry, mRNA and miRNA sequencing, and real-time quantitative polymerase chain reaction (qRT-PCR) validation, we found that in prenatally irradiated (100 mGy/d for 18 days with an accumulative dose of 1.8 Gy) 1-year-old mice, no cellular changes, including immature neurons in the subgranular zone, mature neurons and glial cells in the hilus of the dentate gyrus and development of cognitive impairment, neuropsychiatric disorders, occurred. However, a significant reduction in body weight and mass index (BMI) was indicated by the SHIRPA test. A reduced exploratory behavior was shown by an open field test. Organ weights showed significant reductions in the testes, kidneys, heart, liver and epididymides with no abnormal pathology. mRNA and miRNA sequencing and qRT-PCR validation revealed the upregulation of Rubcnl and Abhd14b, and downregulation of Hspa1b, P4ha1, and Banp genes in both the hippocampus and blood of mice prenatally irradiated with 100 mGy/d. Meanwhile, downregulation of miR-448-3p and miR1298-5p in the hippocampus, miR-320-3p, miR-423-5p, miR-486b-5p, miR-486b-3p, miR-423-3p, miR-652-3p, miR-324-3p, miR-181b-5p, miR-let-7b, and miR-6904-5p in the blood was induced. The target scan revealed that Rubcnl is one of the miR-181b-5p targets in the blood. We, therefore, concluded that prenatal chronic irradiation with a low dose rate of 100 mGy/d and accumulative dose of 1.8 Gy or below might not induce significant adverse health effects on the offspring. Further study of different low dose rate radiation exposures with accumulative high doses may provide threshold doses for authorities or regulators to set new radiation safety guidelines to replace those extrapolated from acute high dose/dose rate irradiation to reduce unnecessary emergency evacuation or spending once a nuclear accident or leakage occurs.
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Hipocampo , MicroARNs , Efectos Tardíos de la Exposición Prenatal , ARN Mensajero , Animales , MicroARNs/genética , MicroARNs/metabolismo , Ratones , Hipocampo/efectos de la radiación , Hipocampo/metabolismo , Hipocampo/patología , Femenino , Embarazo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Efectos Tardíos de la Exposición Prenatal/genética , Masculino , Conducta Animal/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Tamaño de los Órganos/efectos de la radiaciónRESUMEN
Epilepsy is a chronic neurological disorder characterized by recurrent seizures that affects over 70 million people worldwide. Although many antiepileptic drugs that block seizures are available, they have little effect on preventing and curing epilepsy, and their side effects sometimes lead to serious morbidity. Therefore, prophylactic agents with anticonvulsant properties and no adverse effects need to be identified. Recent studies on probiotic administration have reported a variety of beneficial effects on the central nervous system via the microbiota-gut-brain axis. In this study, we investigated the effects of the oral administration of Bifidobacterium breve strain A1 [MCC1274] (B. breve A1) on tonic-clonic seizure in a pentylenetetrazole (PTZ)-induced kindling mouse (KD mouse) model. We found that the oral administration of B. breve A1 every other day for 15 days significantly reduced the seizure score, which gradually increased with repetitive injections of PTZ in KD mice. The administration of B. breve A1, but not saline, to KD mice significantly increased the level of Akt Ser473 phosphorylation (p-Akt) in the hippocampus; this increase was maintained for a minimum of 24 h after PTZ administration. Treatment of B. breve A1-administered KD mice with the selective inhibitor of integrin-linked kinase (ILK) Cpd22 significantly increased the seizure score and blocked the antiepileptic effect of B. breve A1. Moreover, Cpd22 blocked the B. breve A1-induced increase in hippocampal p-Akt levels. These results suggest that the ILK-induced phosphorylation of Akt Ser473 in the hippocampus might be involved in the antiepileptic effect of B. breve A1.