RESUMO
Up to 25% of individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibit postacute cognitive sequelae. Although millions of cases of coronavirus disease 2019 (COVID-19)-mediated memory dysfunction are accumulating worldwide, the underlying mechanisms and how vaccination lowers risk are unknown. Interleukin-1 (IL-1), a key component of innate immune defense against SARS-CoV-2 infection, is elevated in the hippocampi of individuals with COVID-19. Here we show that intranasal infection of C57BL/6J mice with SARS-CoV-2 Beta variant leads to central nervous system infiltration of Ly6Chi monocytes and microglial activation. Accordingly, SARS-CoV-2, but not H1N1 influenza virus, increases levels of brain IL-1ß and induces persistent IL-1R1-mediated loss of hippocampal neurogenesis, which promotes postacute cognitive deficits. Vaccination with a low dose of adenoviral-vectored spike protein prevents hippocampal production of IL-1ß during breakthrough SARS-CoV-2 infection, loss of neurogenesis and subsequent memory deficits. Our study identifies IL-1ß as one potential mechanism driving SARS-CoV-2-induced cognitive impairment in a new mouse model that is prevented by vaccination.
Assuntos
COVID-19 , Hipocampo , Interleucina-1beta , Transtornos da Memória , Camundongos Endogâmicos C57BL , Neurogênese , SARS-CoV-2 , Animais , Interleucina-1beta/metabolismo , Interleucina-1beta/imunologia , Camundongos , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Hipocampo/imunologia , Hipocampo/metabolismo , Transtornos da Memória/imunologia , Neurogênese/imunologia , Vacinação , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas contra COVID-19/imunologia , Masculino , Humanos , Microglia/imunologia , Microglia/metabolismo , Modelos Animais de Doenças , Receptores Tipo I de Interleucina-1/metabolismo , Receptores Tipo I de Interleucina-1/genética , Monócitos/imunologia , Monócitos/metabolismo , FemininoRESUMO
It is unclear how binding of antidepressant drugs to their targets gives rise to the clinical antidepressant effect. We discovered that the transmembrane domain of tyrosine kinase receptor 2 (TRKB), the brain-derived neurotrophic factor (BDNF) receptor that promotes neuronal plasticity and antidepressant responses, has a cholesterol-sensing function that mediates synaptic effects of cholesterol. We then found that both typical and fast-acting antidepressants directly bind to TRKB, thereby facilitating synaptic localization of TRKB and its activation by BDNF. Extensive computational approaches including atomistic molecular dynamics simulations revealed a binding site at the transmembrane region of TRKB dimers. Mutation of the TRKB antidepressant-binding motif impaired cellular, behavioral, and plasticity-promoting responses to antidepressants in vitro and in vivo. We suggest that binding to TRKB and allosteric facilitation of BDNF signaling is the common mechanism for antidepressant action, which may explain why typical antidepressants act slowly and how molecular effects of antidepressants are translated into clinical mood recovery.
Assuntos
Antidepressivos/farmacologia , Receptor trkB/metabolismo , Animais , Antidepressivos/química , Antidepressivos/metabolismo , Sítios de Ligação , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular , Colesterol/metabolismo , Embrião de Mamíferos , Fluoxetina/química , Fluoxetina/metabolismo , Fluoxetina/farmacologia , Hipocampo/metabolismo , Humanos , Camundongos , Modelos Animais , Simulação de Dinâmica Molecular , Domínios Proteicos , Ratos , Receptor trkB/química , Córtex Visual/metabolismoRESUMO
Every day we make decisions critical for adaptation and survival. We repeat actions with known consequences. But we also draw on loosely related events to infer and imagine the outcome of entirely novel choices. These inferential decisions are thought to engage a number of brain regions; however, the underlying neuronal computation remains unknown. Here, we use a multi-day cross-species approach in humans and mice to report the functional anatomy and neuronal computation underlying inferential decisions. We show that during successful inference, the mammalian brain uses a hippocampal prospective code to forecast temporally structured learned associations. Moreover, during resting behavior, coactivation of hippocampal cells in sharp-wave/ripples represent inferred relationships that include reward, thereby "joining-the-dots" between events that have not been observed together but lead to profitable outcomes. Computing mnemonic links in this manner may provide an important mechanism to build a cognitive map that stretches beyond direct experience, thus supporting flexible behavior.
Assuntos
Tomada de Decisões/fisiologia , Rede Nervosa/fisiologia , Pensamento/fisiologia , Animais , Encéfalo/fisiologia , Feminino , Hipocampo/metabolismo , Hipocampo/fisiologia , Humanos , Masculino , Memória/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Neurônios/metabolismo , Neurônios/fisiologia , Estudos Prospectivos , Adulto JovemRESUMO
Synapse remodeling is essential to encode experiences into neuronal circuits. Here, we define a molecular interaction between neurons and microglia that drives experience-dependent synapse remodeling in the hippocampus. We find that the cytokine interleukin-33 (IL-33) is expressed by adult hippocampal neurons in an experience-dependent manner and defines a neuronal subset primed for synaptic plasticity. Loss of neuronal IL-33 or the microglial IL-33 receptor leads to impaired spine plasticity, reduced newborn neuron integration, and diminished precision of remote fear memories. Memory precision and neuronal IL-33 are decreased in aged mice, and IL-33 gain of function mitigates age-related decreases in spine plasticity. We find that neuronal IL-33 instructs microglial engulfment of the extracellular matrix (ECM) and that its loss leads to impaired ECM engulfment and a concomitant accumulation of ECM proteins in contact with synapses. These data define a cellular mechanism through which microglia regulate experience-dependent synapse remodeling and promote memory consolidation.
Assuntos
Matriz Extracelular/metabolismo , Microglia/fisiologia , Plasticidade Neuronal/fisiologia , Envelhecimento , Animais , Medo , Regulação da Expressão Gênica , Hipocampo/metabolismo , Proteína 1 Semelhante a Receptor de Interleucina-1/genética , Proteína 1 Semelhante a Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Memória , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/metabolismo , Transdução de SinaisRESUMO
In order to analyze how a signal transduction network converts cellular inputs into cellular outputs, ideally one would measure the dynamics of many signals within the network simultaneously. We found that, by fusing a fluorescent reporter to a pair of self-assembling peptides, it could be stably clustered within cells at random points, distant enough to be resolved by a microscope but close enough to spatially sample the relevant biology. Because such clusters, which we call signaling reporter islands (SiRIs), can be modularly designed, they permit a set of fluorescent reporters to be efficiently adapted for simultaneous measurement of multiple nodes of a signal transduction network within single cells. We created SiRIs for indicators of second messengers and kinases and used them, in hippocampal neurons in culture and intact brain slices, to discover relationships between the speed of calcium signaling, and the amplitude of PKA signaling, upon receiving a cAMP-driving stimulus.
Assuntos
Corantes Fluorescentes/metabolismo , Genes Reporter , Imagem Óptica , Transdução de Sinais , Animais , Cálcio/metabolismo , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Feminino , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Hipocampo/metabolismo , Humanos , Camundongos , Neurônios/metabolismo , Peptídeos/metabolismo , Proteínas/metabolismo , Células Piramidais/metabolismoRESUMO
New neurons arise from quiescent adult neural progenitors throughout life in specific regions of the mammalian brain. Little is known about the embryonic origin and establishment of adult neural progenitors. Here, we show that Hopx+ precursors in the mouse dentate neuroepithelium at embryonic day 11.5 give rise to proliferative Hopx+ neural progenitors in the primitive dentate region, and they, in turn, generate granule neurons, but not other neurons, throughout development and then transition into Hopx+ quiescent radial glial-like neural progenitors during an early postnatal period. RNA-seq and ATAC-seq analyses of Hopx+ embryonic, early postnatal, and adult dentate neural progenitors further reveal common molecular and epigenetic signatures and developmental dynamics. Together, our findings support a "continuous" model wherein a common neural progenitor population exclusively contributes to dentate neurogenesis throughout development and adulthood. Adult dentate neurogenesis may therefore represent a lifelong extension of development that maintains heightened plasticity in the mammalian hippocampus.
Assuntos
Células-Tronco Embrionárias/metabolismo , Neurogênese , Animais , Diferenciação Celular , Giro Denteado/metabolismo , Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/citologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Hipocampo/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismoRESUMO
To decipher dynamic brain information processing, current genetically encoded calcium indicators (GECIs) are limited in single action potential (AP) detection speed, combinatorial spectral compatibility, and two-photon imaging depth. To address this, here, we rationally engineered a next-generation quadricolor GECI suite, XCaMPs. Single AP detection was achieved within 3-10 ms of spike onset, enabling measurements of fast-spike trains in parvalbumin (PV)-positive interneurons in the barrel cortex in vivo and recording three distinct (two inhibitory and one excitatory) ensembles during pre-motion activity in freely moving mice. In vivo paired recording of pre- and postsynaptic firing revealed spatiotemporal constraints of dendritic inhibition in layer 1 in vivo, between axons of somatostatin (SST)-positive interneurons and apical tufts dendrites of excitatory pyramidal neurons. Finally, non-invasive, subcortical imaging using red XCaMP-R uncovered somatosensation-evoked persistent activity in hippocampal CA1 neurons. Thus, the XCaMPs offer a critical enhancement of solution space in studies of complex neuronal circuit dynamics. VIDEO ABSTRACT.
Assuntos
Potenciais de Ação/fisiologia , Axônios/metabolismo , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Interneurônios/metabolismo , Células Piramidais/metabolismo , Animais , Córtex Cerebral/citologia , Feminino , Hipocampo/citologia , Interneurônios/citologia , Camundongos , Camundongos Transgênicos , Células Piramidais/citologia , Ratos , Ratos Sprague-DawleyRESUMO
We previously reported that inducing gamma oscillations with a non-invasive light flicker (gamma entrainment using sensory stimulus or GENUS) impacted pathology in the visual cortex of Alzheimer's disease mouse models. Here, we designed auditory tone stimulation that drove gamma frequency neural activity in auditory cortex (AC) and hippocampal CA1. Seven days of auditory GENUS improved spatial and recognition memory and reduced amyloid in AC and hippocampus of 5XFAD mice. Changes in activation responses were evident in microglia, astrocytes, and vasculature. Auditory GENUS also reduced phosphorylated tau in the P301S tauopathy model. Furthermore, combined auditory and visual GENUS, but not either alone, produced microglial-clustering responses, and decreased amyloid in medial prefrontal cortex. Whole brain analysis using SHIELD revealed widespread reduction of amyloid plaques throughout neocortex after multi-sensory GENUS. Thus, GENUS can be achieved through multiple sensory modalities with wide-ranging effects across multiple brain areas to improve cognitive function.
Assuntos
Estimulação Acústica/métodos , Doença de Alzheimer/terapia , Cognição/fisiologia , Doença de Alzheimer/patologia , Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Percepção Auditiva/fisiologia , Encéfalo/metabolismo , Modelos Animais de Doenças , Ritmo Gama/fisiologia , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Placa Amiloide/metabolismoRESUMO
The expression of some proteins in the autophagy pathway declines with age, which may impact neurodegeneration in diseases, including Alzheimer's Disease. We have identified a novel non-canonical function of several autophagy proteins in the conjugation of LC3 to Rab5+, clathrin+ endosomes containing ß-amyloid in a process of LC3-associated endocytosis (LANDO). We found that LANDO in microglia is a critical regulator of immune-mediated aggregate removal and microglial activation in a murine model of AD. Mice lacking LANDO but not canonical autophagy in the myeloid compartment or specifically in microglia have a robust increase in pro-inflammatory cytokine production in the hippocampus and increased levels of neurotoxic ß-amyloid. This inflammation and ß-amyloid deposition were associated with reactive microgliosis and tau hyperphosphorylation. LANDO-deficient AD mice displayed accelerated neurodegeneration, impaired neuronal signaling, and memory deficits. Our data support a protective role for LANDO in microglia in neurodegenerative pathologies resulting from ß-amyloid deposition.
Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Endocitose , Proteínas Associadas aos Microtúbulos/metabolismo , Doença de Alzheimer/metabolismo , Animais , Proteína 5 Relacionada à Autofagia/deficiência , Proteína 5 Relacionada à Autofagia/genética , Proteínas Relacionadas à Autofagia/deficiência , Proteínas Relacionadas à Autofagia/genética , Antígenos CD36/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Microglia/citologia , Microglia/metabolismo , Células RAW 264.7 , Receptores Imunológicos/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
The mammalian hippocampus, comprised of serially connected subfields, participates in diverse behavioral and cognitive functions. It has been postulated that parallel circuitry embedded within hippocampal subfields may underlie such functional diversity. We sought to identify, delineate, and manipulate this putatively parallel architecture in the dorsal subiculum, the primary output subfield of the dorsal hippocampus. Population and single-cell RNA-seq revealed that the subiculum can be divided into two spatially adjacent subregions associated with prominent differences in pyramidal cell gene expression. Pyramidal cells occupying these two regions differed in their long-range inputs, local wiring, projection targets, and electrophysiological properties. Leveraging gene-expression differences across these regions, we use genetically restricted neuronal silencing to show that these regions differentially contribute to spatial working memory. This work provides a coherent molecular-, cellular-, circuit-, and behavioral-level demonstration that the hippocampus embeds structurally and functionally dissociable streams within its serial architecture.
Assuntos
Hipocampo/metabolismo , Animais , Axônios/fisiologia , Comportamento Animal , Encéfalo/metabolismo , Encéfalo/patologia , Feminino , Hipocampo/citologia , Técnicas In Vitro , Masculino , Aprendizagem em Labirinto , Memória de Curto Prazo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Técnicas de Patch-Clamp , Análise de Componente Principal , Células Piramidais/citologia , Células Piramidais/metabolismo , Análise de Sequência de RNA , TranscriptomaRESUMO
The ketogenic diet (KD) is used to treat refractory epilepsy, but the mechanisms underlying its neuroprotective effects remain unclear. Here, we show that the gut microbiota is altered by the KD and required for protection against acute electrically induced seizures and spontaneous tonic-clonic seizures in two mouse models. Mice treated with antibiotics or reared germ free are resistant to KD-mediated seizure protection. Enrichment of, and gnotobiotic co-colonization with, KD-associated Akkermansia and Parabacteroides restores seizure protection. Moreover, transplantation of the KD gut microbiota and treatment with Akkermansia and Parabacteroides each confer seizure protection to mice fed a control diet. Alterations in colonic lumenal, serum, and hippocampal metabolomic profiles correlate with seizure protection, including reductions in systemic gamma-glutamylated amino acids and elevated hippocampal GABA/glutamate levels. Bacterial cross-feeding decreases gamma-glutamyltranspeptidase activity, and inhibiting gamma-glutamylation promotes seizure protection in vivo. Overall, this study reveals that the gut microbiota modulates host metabolism and seizure susceptibility in mice.
Assuntos
Dieta Cetogênica , Microbioma Gastrointestinal , Convulsões/dietoterapia , Animais , Antibacterianos/farmacologia , Bacteroides/efeitos dos fármacos , Bacteroides/genética , Bacteroides/isolamento & purificação , Modelos Animais de Doenças , Fezes/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Mucosa Intestinal/metabolismo , Canal de Potássio Kv1.1/deficiência , Canal de Potássio Kv1.1/genética , Metaboloma/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C3H , Camundongos Knockout , Análise de Componente Principal , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Convulsões/patologia , Ácido gama-Aminobutírico/metabolismo , gama-Glutamiltransferase/metabolismoRESUMO
The formation and retrieval of a memory is thought to be accomplished by activation and reactivation, respectively, of the memory-holding cells (engram cells) by a common set of neural circuits, but this hypothesis has not been established. The medial temporal-lobe system is essential for the formation and retrieval of episodic memory for which individual hippocampal subfields and entorhinal cortex layers contribute by carrying out specific functions. One subfield whose function is poorly known is the subiculum. Here, we show that dorsal subiculum and the circuit, CA1 to dorsal subiculum to medial entorhinal cortex layer 5, play a crucial role selectively in the retrieval of episodic memories. Conversely, the direct CA1 to medial entorhinal cortex layer 5 circuit is essential specifically for memory formation. Our data suggest that the subiculum-containing detour loop is dedicated to meet the requirements associated with recall such as rapid memory updating and retrieval-driven instinctive fear responses.
Assuntos
Córtex Entorrinal/metabolismo , Hipocampo/metabolismo , Memória Episódica , Vias Neurais , Animais , Corticosterona/metabolismo , Córtex Entorrinal/citologia , Expressão Gênica , Hipocampo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , OptogenéticaRESUMO
Early prenatal inflammatory conditions are thought to be a risk factor for different neurodevelopmental disorders. Maternal interleukin-6 (IL-6) elevation during pregnancy causes abnormal behavior in offspring, but whether these defects result from altered synaptic developmental trajectories remains unclear. Here we showed that transient IL-6 elevation via injection into pregnant mice or developing embryos enhanced glutamatergic synapses and led to overall brain hyperconnectivity in offspring into adulthood. IL-6 activated synaptogenesis gene programs in glutamatergic neurons and required the transcription factor STAT3 and expression of the RGS4 gene. The STAT3-RGS4 pathway was also activated in neonatal brains during poly(I:C)-induced maternal immune activation, which mimics viral infection during pregnancy. These findings indicate that IL-6 elevation at early developmental stages is sufficient to exert a long-lasting effect on glutamatergic synaptogenesis and brain connectivity, providing a mechanistic framework for the association between prenatal inflammatory events and brain neurodevelopmental disorders.
Assuntos
Hipocampo/metabolismo , Interleucina-6/biossíntese , Exposição Materna , Neurônios/metabolismo , Efeitos Tardios da Exposição Pré-Natal , Sinapses/metabolismo , Animais , Citocinas/biossíntese , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Hipocampo/fisiopatologia , Mediadores da Inflamação/metabolismo , Camundongos , Gravidez , Transdução de Sinais , Transmissão SinápticaRESUMO
The ghrelin receptor (GHSR1a) and dopamine receptor-1 (DRD1) are coexpressed in hippocampal neurons, yet ghrelin is undetectable in the hippocampus; therefore, we sought a function for apo-GHSR1a. Real-time single-molecule analysis on hippocampal neurons revealed dimerization between apo-GHSR1a and DRD1 that is enhanced by DRD1 agonism. In addition, proximity measurements support formation of preassembled apo-GHSR1a:DRD1:Gαq heteromeric complexes in hippocampal neurons. Activation by a DRD1 agonist produced non-canonical signal transduction via Gαq-PLC-IP3-Ca(2+) at the expense of canonical DRD1 Gαs cAMP signaling to result in CaMKII activation, glutamate receptor exocytosis, synaptic reorganization, and expression of early markers of hippocampal synaptic plasticity. Remarkably, this pathway is blocked by genetic or pharmacological inactivation of GHSR1a. In mice, GHSR1a inactivation inhibits DRD1-mediated hippocampal behavior and memory. Our findings identify a previously unrecognized mechanism essential for DRD1 initiation of hippocampal synaptic plasticity that is dependent on GHSR1a, and independent of cAMP signaling.
Assuntos
Dopamina/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Grelina/metabolismo , Transdução de Sinais , Animais , Células Cultivadas , Hipocampo/metabolismo , Memória , Camundongos , Plasticidade Neuronal , Receptores de Dopamina D1/agonistasRESUMO
α- and ß-neurexins are presynaptic cell-adhesion molecules implicated in autism and schizophrenia. We find that, although ß-neurexins are expressed at much lower levels than α-neurexins, conditional knockout of ß-neurexins with continued expression of α-neurexins dramatically decreased neurotransmitter release at excitatory synapses in cultured cortical neurons. The ß-neurexin knockout phenotype was attenuated by CB1-receptor inhibition, which blocks presynaptic endocannabinoid signaling, or by 2-arachidonoylglycerol synthesis inhibition, which impairs postsynaptic endocannabinoid release. In synapses formed by CA1-region pyramidal neurons onto burst-firing subiculum neurons, presynaptic in vivo knockout of ß-neurexins aggravated endocannabinoid-mediated inhibition of synaptic transmission and blocked LTP; presynaptic CB1-receptor antagonists or postsynaptic 2-arachidonoylglycerol synthesis inhibition again reversed this block. Moreover, conditional knockout of ß-neurexins in CA1-region neurons impaired contextual fear memories. Thus, our data suggest that presynaptic ß-neurexins control synaptic strength in excitatory synapses by regulating postsynaptic 2-arachidonoylglycerol synthesis, revealing an unexpected role for ß-neurexins in the endocannabinoid-dependent regulation of neural circuits.
Assuntos
Endocanabinoides/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Vias Neurais/metabolismo , Sinapses/metabolismo , Animais , Ácidos Araquidônicos/biossíntese , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio , Endocanabinoides/biossíntese , Glicerídeos/biossíntese , Hipocampo/citologia , Hipocampo/metabolismo , Camundongos , Camundongos Knockout , Moléculas de Adesão de Célula Nervosa/genética , Neurônios/metabolismo , Neurotransmissores/metabolismo , Transdução de SinaisRESUMO
Recent technological innovations have enabled the high-throughput quantification of gene expression and epigenetic regulation within individual cells, transforming our understanding of how complex tissues are constructed1-6. However, missing from these measurements is the ability to routinely and easily spatially localize these profiled cells. We developed a strategy, Slide-tags, in which single nuclei within an intact tissue section are tagged with spatial barcode oligonucleotides derived from DNA-barcoded beads with known positions. These tagged nuclei can then be used as an input into a wide variety of single-nucleus profiling assays. Application of Slide-tags to the mouse hippocampus positioned nuclei at less than 10 µm spatial resolution and delivered whole-transcriptome data that are indistinguishable in quality from ordinary single-nucleus RNA-sequencing data. To demonstrate that Slide-tags can be applied to a wide variety of human tissues, we performed the assay on brain, tonsil and melanoma. We revealed cell-type-specific spatially varying gene expression across cortical layers and spatially contextualized receptor-ligand interactions driving B cell maturation in lymphoid tissue. A major benefit of Slide-tags is that it is easily adaptable to almost any single-cell measurement technology. As a proof of principle, we performed multiomic measurements of open chromatin, RNA and T cell receptor (TCR) sequences in the same cells from metastatic melanoma, identifying transcription factor motifs driving cancer cell state transitions in spatially distinct microenvironments. Slide-tags offers a universal platform for importing the compendium of established single-cell measurements into the spatial genomics repertoire.
Assuntos
Código de Barras de DNA Taxonômico , Genômica , Animais , Humanos , Camundongos , Encéfalo/citologia , Encéfalo/metabolismo , Cromatina/genética , Cromatina/metabolismo , Código de Barras de DNA Taxonômico/métodos , Epigênese Genética , Perfilação da Expressão Gênica , Genômica/métodos , Melanoma/genética , Melanoma/patologia , Tonsila Palatina/citologia , Tonsila Palatina/metabolismo , Receptores de Antígenos de Linfócitos T/genética , RNA/genética , Análise de Célula Única/métodos , Transcriptoma/genética , Microambiente Tumoral , Hipocampo/citologia , Hipocampo/metabolismo , Análise da Expressão Gênica de Célula Única , Especificidade de Órgãos , Ligantes , Elementos de Resposta/genética , Fatores de Transcrição/metabolismoRESUMO
Brain computation performed by billions of nerve cells relies on a sufficient and uninterrupted nutrient and oxygen supply1,2. Astrocytes, the ubiquitous glial neighbours of neurons, govern brain glucose uptake and metabolism3,4, but the exact mechanisms of metabolic coupling between neurons and astrocytes that ensure on-demand support of neuronal energy needs are not fully understood5,6. Here we show, using experimental in vitro and in vivo animal models, that neuronal activity-dependent metabolic activation of astrocytes is mediated by neuromodulator adenosine acting on astrocytic A2B receptors. Stimulation of A2B receptors recruits the canonical cyclic adenosine 3',5'-monophosphate-protein kinase A signalling pathway, leading to rapid activation of astrocyte glucose metabolism and the release of lactate, which supplements the extracellular pool of readily available energy substrates. Experimental mouse models involving conditional deletion of the gene encoding A2B receptors in astrocytes showed that adenosine-mediated metabolic signalling is essential for maintaining synaptic function, especially under conditions of high energy demand or reduced energy supply. Knockdown of A2B receptor expression in astrocytes led to a major reprogramming of brain energy metabolism, prevented synaptic plasticity in the hippocampus, severely impaired recognition memory and disrupted sleep. These data identify the adenosine A2B receptor as an astrocytic sensor of neuronal activity and show that cAMP signalling in astrocytes tunes brain energy metabolism to support its fundamental functions such as sleep and memory.
Assuntos
Adenosina , Astrócitos , Encéfalo , Metabolismo Energético , Neurônios , Transdução de Sinais , Animais , Feminino , Masculino , Camundongos , Ratos , Adenosina/metabolismo , Astrócitos/metabolismo , Encéfalo/metabolismo , Encéfalo/citologia , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Glucose/metabolismo , Hipocampo/metabolismo , Hipocampo/citologia , Ácido Láctico/metabolismo , Camundongos Endogâmicos C57BL , Plasticidade Neuronal , Neurônios/metabolismo , Receptor A2B de Adenosina/deficiência , Receptor A2B de Adenosina/efeitos dos fármacos , Receptor A2B de Adenosina/genética , Receptor A2B de Adenosina/metabolismo , Reconhecimento Psicológico/fisiologia , Sono/genética , Sono/fisiologia , Sinapses/metabolismoRESUMO
Traumatic events generate some of the most enduring forms of memories. Despite the elevated lifetime prevalence of anxiety disorders, effective strategies to attenuate long-term traumatic memories are scarce. The most efficacious treatments to diminish recent (i.e., day-old) traumata capitalize on memory updating mechanisms during reconsolidation that are initiated upon memory recall. Here, we show that, in mice, successful reconsolidation-updating paradigms for recent memories fail to attenuate remote (i.e., month-old) ones. We find that, whereas recent memory recall induces a limited period of hippocampal neuroplasticity mediated, in part, by S-nitrosylation of HDAC2 and histone acetylation, such plasticity is absent for remote memories. However, by using an HDAC2-targeting inhibitor (HDACi) during reconsolidation, even remote memories can be persistently attenuated. This intervention epigenetically primes the expression of neuroplasticity-related genes, which is accompanied by higher metabolic, synaptic, and structural plasticity. Thus, applying HDACis during memory reconsolidation might constitute a treatment option for remote traumata.
Assuntos
Medo , Memória de Longo Prazo , Plasticidade Neuronal , Animais , Epigênese Genética , Hipocampo/metabolismo , Histona Desacetilase 2/metabolismo , Inibidores de Histona Desacetilases/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Masculino , Memória de Longo Prazo/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , TranscriptomaRESUMO
Cells allocate substantial resources toward monitoring levels of nutrients that can be used for ATP generation by mitochondria. Among the many specialized cell types, neurons are particularly dependent on mitochondria due to their complex morphology and regional energy needs. Here, we report a molecular mechanism by which nutrient availability in the form of extracellular glucose and the enzyme O-GlcNAc Transferase (OGT), whose activity depends on glucose availability, regulates mitochondrial motility in neurons. Activation of OGT diminishes mitochondrial motility. We establish the mitochondrial motor-adaptor protein Milton as a required substrate for OGT to arrest mitochondrial motility by mapping and mutating the key O-GlcNAcylated serine residues. We find that the GlcNAcylation state of Milton is altered by extracellular glucose and that OGT alters mitochondrial motility in vivo. Our findings suggest that, by dynamically regulating Milton GlcNAcylation, OGT tailors mitochondrial dynamics in neurons based on nutrient availability.
Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Glucose/metabolismo , Mitocôndrias/metabolismo , N-Acetilglucosaminiltransferases/metabolismo , Animais , Axônios/metabolismo , Proteínas de Transporte , Drosophila melanogaster , Técnicas de Silenciamento de Genes , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , N-Acetilglucosaminiltransferases/genética , Ratos , Alinhamento de SequênciaRESUMO
Cyclin-dependent kinase 5 regulates numerous neuronal functions with its activator, p35. Under neurotoxic conditions, p35 undergoes proteolytic cleavage to liberate p25, which has been implicated in various neurodegenerative diseases. Here, we show that p25 is generated following neuronal activity under physiological conditions in a GluN2B- and CaMKIIα-dependent manner. Moreover, we developed a knockin mouse model in which endogenous p35 is replaced with a calpain-resistant mutant p35 (Δp35KI) to prevent p25 generation. The Δp35KI mice exhibit impaired long-term depression and defective memory extinction, likely mediated through persistent GluA1 phosphorylation at Ser845. Finally, crossing the Δp35KI mice with the 5XFAD mouse model of Alzheimer's disease (AD) resulted in an amelioration of ß-amyloid (Aß)-induced synaptic depression and cognitive impairment. Together, these results reveal a physiological role of p25 production in synaptic plasticity and memory and provide new insights into the function of p25 in Aß-associated neurotoxicity and AD-like pathology.