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1.
Cell ; 185(1): 62-76, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34963057

RESUMO

Brain-derived neurotrophic factor (BDNF) is a neuropeptide that plays numerous important roles in synaptic development and plasticity. While its importance in fundamental physiology is well established, studies of BDNF often produce conflicting and unclear results, and the scope of existing research makes the prospect of setting future directions daunting. In this review, we examine the importance of spatial and temporal factors on BDNF activity, particularly in processes such as synaptogenesis, Hebbian plasticity, homeostatic plasticity, and the treatment of psychiatric disorders. Understanding the fundamental physiology of when, where, and how BDNF acts and new approaches to control BDNF signaling in time and space can contribute to improved therapeutics and patient outcomes.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Encéfalo/metabolismo , Transtornos Mentais/metabolismo , Plasticidade Neuronal/fisiologia , Neuropeptídeos/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Homeostase/fisiologia , Humanos , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/genética , Neurogênese/fisiologia , Neuropeptídeos/genética , Psicotrópicos/farmacologia , Psicotrópicos/uso terapêutico , Transmissão Sináptica/efeitos dos fármacos , Resultado do Tratamento
2.
Cell ; 184(5): 1299-1313.e19, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33606976

RESUMO

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/metabolismo
3.
Nature ; 627(8003): 374-381, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38326616

RESUMO

Memory encodes past experiences, thereby enabling future plans. The basolateral amygdala is a centre of salience networks that underlie emotional experiences and thus has a key role in long-term fear memory formation1. Here we used spatial and single-cell transcriptomics to illuminate the cellular and molecular architecture of the role of the basolateral amygdala in long-term memory. We identified transcriptional signatures in subpopulations of neurons and astrocytes that were memory-specific and persisted for weeks. These transcriptional signatures implicate neuropeptide and BDNF signalling, MAPK and CREB activation, ubiquitination pathways, and synaptic connectivity as key components of long-term memory. Notably, upon long-term memory formation, a neuronal subpopulation defined by increased Penk and decreased Tac expression constituted the most prominent component of the memory engram of the basolateral amygdala. These transcriptional changes were observed both with single-cell RNA sequencing and with single-molecule spatial transcriptomics in intact slices, thereby providing a rich spatial map of a memory engram. The spatial data enabled us to determine that this neuronal subpopulation interacts with adjacent astrocytes, and functional experiments show that neurons require interactions with astrocytes to encode long-term memory.


Assuntos
Astrócitos , Comunicação Celular , Perfilação da Expressão Gênica , Memória de Longo Prazo , Neurônios , Astrócitos/citologia , Astrócitos/metabolismo , Astrócitos/fisiologia , Complexo Nuclear Basolateral da Amígdala/citologia , Complexo Nuclear Basolateral da Amígdala/metabolismo , Complexo Nuclear Basolateral da Amígdala/fisiologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Memória de Longo Prazo/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Neurônios/fisiologia , Análise de Sequência de RNA , Imagem Individual de Molécula , Análise da Expressão Gênica de Célula Única , Ubiquitinação
4.
Cell ; 159(7): 1640-51, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25525881

RESUMO

The perception of touch, including the direction of stimulus movement across the skin, begins with activation of low-threshold mechanosensory neurons (LTMRs) that innervate the skin. Here, we show that murine Aδ-LTMRs are preferentially tuned to deflection of body hairs in the caudal-to-rostral direction. This tuning property is explained by the finding that Aδ-LTMR lanceolate endings around hair follicles are polarized; they are concentrated on the caudal (downward) side of each hair follicle. The neurotrophic factor BDNF is synthesized in epithelial cells on the caudal, but not rostral, side of hair follicles, in close proximity to Aδ-LTMR lanceolate endings, which express TrkB. Moreover, ablation of BDNF in hair follicle epithelial cells disrupts polarization of Aδ-LTMR lanceolate endings and results in randomization of Aδ-LTMR responses to hair deflection. Thus, BDNF-TrkB signaling directs polarization of Aδ-LTMR lanceolate endings, which underlies direction-selective responsiveness of Aδ-LTMRs to hair deflection.


Assuntos
Gânglios Espinais/fisiologia , Folículo Piloso/fisiologia , Mecanorreceptores/fisiologia , Tato , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Embrião de Mamíferos , Células Epiteliais/fisiologia , Folículo Piloso/citologia , Técnicas In Vitro , Mecanorreceptores/classificação , Camundongos , Receptor trkB/metabolismo
5.
Nature ; 623(7986): 366-374, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37914930

RESUMO

The role of the nervous system in the regulation of cancer is increasingly appreciated. In gliomas, neuronal activity drives tumour progression through paracrine signalling factors such as neuroligin-3 and brain-derived neurotrophic factor1-3 (BDNF), and also through electrophysiologically functional neuron-to-glioma synapses mediated by AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors4,5. The consequent glioma cell membrane depolarization drives tumour proliferation4,6. In the healthy brain, activity-regulated secretion of BDNF promotes adaptive plasticity of synaptic connectivity7,8 and strength9-15. Here we show that malignant synapses exhibit similar plasticity regulated by BDNF. Signalling through the receptor tropomyosin-related kinase B16 (TrkB) to CAMKII, BDNF promotes AMPA receptor trafficking to the glioma cell membrane, resulting in increased amplitude of glutamate-evoked currents in the malignant cells. Linking plasticity of glioma synaptic strength to tumour growth, graded optogenetic control of glioma membrane potential demonstrates that greater depolarizing current amplitude promotes increased glioma proliferation. This potentiation of malignant synaptic strength shares mechanistic features with synaptic plasticity17-22 that contributes to memory and learning in the healthy brain23-26. BDNF-TrkB signalling also regulates the number of neuron-to-glioma synapses. Abrogation of activity-regulated BDNF secretion from the brain microenvironment or loss of glioma TrkB expression robustly inhibits tumour progression. Blocking TrkB genetically or pharmacologically abrogates these effects of BDNF on glioma synapses and substantially prolongs survival in xenograft models of paediatric glioblastoma and diffuse intrinsic pontine glioma. Together, these findings indicate that BDNF-TrkB signalling promotes malignant synaptic plasticity and augments tumour progression.


Assuntos
Adaptação Fisiológica , Glioma , Plasticidade Neuronal , Sinapses , Animais , Criança , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proliferação de Células , Progressão da Doença , Glioma/metabolismo , Glioma/patologia , Ácido Glutâmico/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Receptor trkB/genética , Receptor trkB/metabolismo , Receptores de AMPA/metabolismo , Transdução de Sinais , Sinapses/metabolismo , Microambiente Tumoral , Optogenética
6.
Trends Biochem Sci ; 49(5): 445-456, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38433044

RESUMO

TrkB (neuronal receptor tyrosine kinase-2, NTRK2) is the receptor for brain-derived neurotrophic factor (BDNF) and is a critical regulator of activity-dependent neuronal plasticity. The past few years have witnessed an increasing understanding of the structure and function of TrkB, including its transmembrane domain (TMD). TrkB interacts with membrane cholesterol, which bidirectionally regulates TrkB signaling. Additionally, TrkB has recently been recognized as a binding target of antidepressant drugs. A variety of different antidepressants, including typical and rapid-acting antidepressants, as well as psychedelic compounds, act as allosteric potentiators of BDNF signaling through TrkB. This suggests that TrkB is the common target of different antidepressant compounds. Although more research is needed, current knowledge suggests that TrkB is a promising target for further drug development.


Assuntos
Glicoproteínas de Membrana , Receptor trkB , Humanos , Receptor trkB/metabolismo , Receptor trkB/química , Animais , Domínios Proteicos , Transdução de Sinais , Antidepressivos/uso terapêutico , Antidepressivos/farmacologia , Antidepressivos/química , Antidepressivos/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/química
7.
Cell ; 155(7): 1596-609, 2013 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-24360280

RESUMO

Microglia are the resident macrophages of the CNS, and their functions have been extensively studied in various brain pathologies. The physiological roles of microglia in brain plasticity and function, however, remain unclear. To address this question, we generated CX3CR1(CreER) mice expressing tamoxifen-inducible Cre recombinase that allow for specific manipulation of gene function in microglia. Using CX3CR1(CreER) to drive diphtheria toxin receptor expression in microglia, we found that microglia could be specifically depleted from the brain upon diphtheria toxin administration. Mice depleted of microglia showed deficits in multiple learning tasks and a significant reduction in motor-learning-dependent synapse formation. Furthermore, Cre-dependent removal of brain-derived neurotrophic factor (BDNF) from microglia largely recapitulated the effects of microglia depletion. Microglial BDNF increases neuronal tropomyosin-related kinase receptor B phosphorylation, a key mediator of synaptic plasticity. Together, our findings reveal that microglia serve important physiological functions in learning and memory by promoting learning-related synapse formation through BDNF signaling.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Aprendizagem/fisiologia , Microglia/fisiologia , Sinapses , Animais , Receptor 1 de Quimiocina CX3C , Expressão Gênica , Camundongos , Microglia/citologia , Plasticidade Neuronal , Proteínas Quinases/metabolismo , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/metabolismo , Transdução de Sinais
8.
Cell ; 148(5): 933-46, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22385959

RESUMO

Control of translation is a fundamental source of regulation in gene expression. The induction of protein synthesis by brain-derived neurotrophic factor (BDNF) critically contributes to enduring modifications of synaptic function, but how BDNF selectively affects only a minority of expressed mRNAs is poorly understood. We report that BDNF rapidly elevates Dicer, increasing mature miRNA levels and inducing RNA processing bodies in neurons. BDNF also rapidly induces Lin28, causing selective loss of Lin28-regulated miRNAs and a corresponding upregulation in translation of their target mRNAs. Binding sites for Lin28-regulated miRNAs are necessary and sufficient to confer BDNF responsiveness to a transcript. Lin28 deficiency, or expression of a Lin28-resistant Let-7 precursor miRNA, inhibits BDNF translation specificity and BDNF-dependent dendrite arborization. Our data establish that specificity in BDNF-regulated translation depends upon a two-part posttranscriptional control of miRNA biogenesis that generally enhances mRNA repression in association with GW182 while selectively derepressing and increasing translation of specific mRNAs.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Biossíntese de Proteínas , Animais , Autoantígenos , RNA Helicases DEAD-box/metabolismo , Hipocampo/citologia , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Neurônios/metabolismo , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA/genética , Ribonuclease III/metabolismo
9.
Proc Natl Acad Sci U S A ; 121(17): e2303664121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38621124

RESUMO

Brain-derived neurotrophic factor (BDNF) plays a critical role in synaptic physiology, as well as mechanisms underlying various neuropsychiatric diseases and their treatment. Despite its clear physiological role and disease relevance, BDNF's function at the presynaptic terminal, a fundamental unit of neurotransmission, remains poorly understood. In this study, we evaluated single synapse dynamics using optical imaging techniques in hippocampal cell cultures. We find that exogenous BDNF selectively increases evoked excitatory neurotransmission without affecting spontaneous neurotransmission. However, acutely blocking endogenous BDNF has no effect on evoked or spontaneous release, demonstrating that different approaches to studying BDNF may yield different results. When we suppressed BDNF-Tropomyosin receptor kinase B (TrkB) activity chronically over a period of days to weeks using a mouse line enabling conditional knockout of TrkB, we found that evoked glutamate release was significantly decreased while spontaneous release remained unchanged. Moreover, chronic blockade of BDNF-TrkB activity selectively downscales evoked calcium transients without affecting spontaneous calcium events. Via pharmacological blockade by voltage-gated calcium channel (VGCC) selective blockers, we found that the changes in evoked calcium transients are mediated by the P/Q subtype of VGCCs. These results suggest that BDNF-TrkB activity increases presynaptic VGCC activity to selectively increase evoked glutamate release.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Cálcio , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cálcio/metabolismo , Transmissão Sináptica/fisiologia , Sinapses/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Cálcio da Dieta , Receptor trkB/genética , Receptor trkB/metabolismo , Glutamatos/metabolismo
10.
Proc Natl Acad Sci U S A ; 121(19): e2313590121, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38683978

RESUMO

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Exossomos , Músculo Esquelético , Exossomos/metabolismo , Animais , Músculo Esquelético/metabolismo , Músculo Esquelético/inervação , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Camundongos , Fibronectinas/metabolismo , Neurônios Motores/metabolismo , Interleucina-6/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Neurônios/metabolismo , Fatores de Crescimento Neural/metabolismo , Miocinas
11.
Nature ; 583(7818): 839-844, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32699414

RESUMO

Mutations in the leptin gene (ob) result in a metabolic disorder that includes severe obesity1, and defects in thermogenesis2 and lipolysis3, both of which are adipose tissue functions regulated by the sympathetic nervous system. However, the basis of these sympathetic-associated abnormalities remains unclear. Furthermore, chronic leptin administration reverses these abnormalities in adipose tissue, but the underlying mechanism remains to be discovered. Here we report that ob/ob mice, as well as leptin-resistant diet-induced obese mice, show significant reductions of sympathetic innervation of subcutaneous white and brown adipose tissue. Chronic leptin treatment of ob/ob mice restores adipose tissue sympathetic innervation, which in turn is necessary to correct the associated functional defects. The effects of leptin on innervation are mediated via agouti-related peptide and pro-opiomelanocortin neurons in the hypothalamic arcuate nucleus. Deletion of the gene encoding the leptin receptor in either population leads to reduced innervation in fat. These agouti-related peptide and pro-opiomelanocortin neurons act via brain-derived neurotropic factor-expressing neurons in the paraventricular nucleus of the hypothalamus (BDNFPVH). Deletion of BDNFPVH blunts the effects of leptin on innervation. These data show that leptin signalling regulates the plasticity of sympathetic architecture of adipose tissue via a top-down neural pathway that is crucial for energy homeostasis.


Assuntos
Tecido Adiposo/inervação , Tecido Adiposo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Leptina/metabolismo , Sistema Nervoso Simpático/fisiologia , Proteína Relacionada com Agouti/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/citologia , Núcleo Arqueado do Hipotálamo/metabolismo , Leptina/deficiência , Lipólise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Pró-Opiomelanocortina/metabolismo , Transdução de Sinais , Gordura Subcutânea/inervação , Gordura Subcutânea/metabolismo , Termogênese
12.
Proc Natl Acad Sci U S A ; 120(3): e2214833120, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36634145

RESUMO

We have previously shown that recovery of visual responses to a deprived eye during the critical period in mouse primary visual cortex requires phosphorylation of the TrkB receptor for BDNF [M. Kaneko, J. L. Hanover, P. M. England, M. P. Stryker, Nat. Neurosci. 11, 497-504 (2008)]. We have now studied the temporal relationship between the production of mature BDNF and the recovery of visual responses under several different conditions. Visual cortical responses to an eye whose vision has been occluded for several days during the critical period and is then re-opened recover rapidly during binocular vision or much more slowly following reverse occlusion, when the previously intact fellow eye is occluded in a model of "patch therapy" for amblyopia. The time to recovery of visual responses differed by more than 18 h between these two procedures, but in each, the production of mature BDNF preceded the physiological recovery. These findings suggest that a spurt of BDNF production is permissive for the growth of connections serving the deprived eye to restore visual responses. Attenuation of recovery of deprived-eye responses by interference with TrkB receptor activation or reduction of BDNF production by interference with homeostatic synaptic scaling had effects consistent with this suggestion.


Assuntos
Ambliopia , Córtex Visual , Camundongos , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Receptor trkB/metabolismo , Córtex Visual/fisiologia , Visão Ocular , Privação Sensorial/fisiologia , Plasticidade Neuronal/fisiologia
13.
J Neurosci ; 44(23)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38719446

RESUMO

Drugs of abuse cause changes in the prefrontal cortex (PFC) and associated regions that impair inhibitory control over drug-seeking. Breaking the contingencies between drug-associated cues and the delivery of the reward during extinction learning reduces relapse. Vagus nerve stimulation (VNS) has previously been shown to enhance extinction learning and reduce drug-seeking. Here we determined the effects of VNS-mediated release of brain-derived neurotrophic factor (BDNF) on extinction and cue-induced reinstatement in male rats trained to self-administer cocaine. Pairing 10 d of extinction training with VNS facilitated extinction and reduced drug-seeking behavior during reinstatement. Rats that received a single extinction session with VNS showed elevated BDNF levels in the medial PFC as determined via an enzyme-linked immunosorbent assay. Systemic blockade of tropomyosin receptor kinase B (TrkB) receptors during extinction, via the TrkB antagonist ANA-12, decreased the effects of VNS on extinction and reinstatement. Whole-cell recordings in brain slices showed that cocaine self-administration induced alterations in the ratio of AMPA and NMDA receptor-mediated currents in Layer 5 pyramidal neurons of the infralimbic cortex (IL). Pairing extinction with VNS reversed cocaine-induced changes in glutamatergic transmission by enhancing AMPAR currents, and this effect was blocked by ANA-12. Our study suggests that VNS consolidates the extinction of drug-seeking behavior by reversing drug-induced changes in synaptic AMPA receptors in the IL, and this effect is abolished by blocking TrkB receptors during extinction, highlighting a potential mechanism for the therapeutic effects of VNS in addiction.


Assuntos
Comportamento de Procura de Droga , Extinção Psicológica , Plasticidade Neuronal , Córtex Pré-Frontal , Ratos Sprague-Dawley , Receptor trkB , Estimulação do Nervo Vago , Animais , Masculino , Ratos , Estimulação do Nervo Vago/métodos , Comportamento de Procura de Droga/fisiologia , Comportamento de Procura de Droga/efeitos dos fármacos , Receptor trkB/metabolismo , Receptor trkB/antagonistas & inibidores , Plasticidade Neuronal/fisiologia , Plasticidade Neuronal/efeitos dos fármacos , Extinção Psicológica/fisiologia , Extinção Psicológica/efeitos dos fármacos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Autoadministração , Cocaína/farmacologia , Cocaína/administração & dosagem
14.
J Biol Chem ; 300(6): 107411, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38796067

RESUMO

The myocyte enhancer factor (MEF2) family of transcription factors, originally discovered for its pivotal role in muscle development and function, has emerged as an essential regulator in various aspects of brain development and neuronal plasticity. The MEF2 transcription factors are known to regulate numerous important genes in the nervous system, including brain-derived neurotrophic factor (BDNF), a small secreted neurotrophin responsible for promoting the survival, growth, and differentiation of neurons. The expression of the Bdnf gene is spatiotemporally controlled by various transcription factors binding to both its proximal and distal regulatory regions. While previous studies have investigated the connection between MEF2 transcription factors and Bdnf, the endogenous function of MEF2 factors in the transcriptional regulation of Bdnf remains largely unknown. Here, we aimed to deepen the knowledge of MEF2 transcription factors and their role in the regulation of Bdnf comparatively in rat cortical and hippocampal neurons. As a result, we demonstrate that the MEF2 transcription factor-dependent enhancer located at -4.8 kb from the Bdnf gene regulates the endogenous expression of Bdnf in hippocampal neurons. In addition, we confirm neuronal activity-dependent activation of the -4.8 kb enhancer in vivo. Finally, we show that specific MEF2 family transcription factors have unique roles in the regulation of Bdnf, with the specific function varying based on the particular brain region and stimuli. Altogether, we present MEF2 family transcription factors as crucial regulators of Bdnf expression, fine-tuning Bdnf expression through both distal and proximal regulatory regions.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Elementos Facilitadores Genéticos , Hipocampo , Fatores de Transcrição MEF2 , Neurônios , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fatores de Transcrição MEF2/metabolismo , Fatores de Transcrição MEF2/genética , Animais , Hipocampo/metabolismo , Hipocampo/citologia , Neurônios/metabolismo , Neurônios/citologia , Ratos , Córtex Cerebral/metabolismo , Córtex Cerebral/citologia , Regulação da Expressão Gênica , Células Cultivadas , Ratos Sprague-Dawley
15.
Genes Cells ; 29(1): 99-105, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38009531

RESUMO

Suppressor of cancer cell invasion (SCAI) acts as a transcriptional repressor of serum response factor (SRF)-mediated gene expression by binding to megakaryoblastic leukemia (MKL)/myocardin-related transcription factor (MRTF), which is an SRF transcriptional coactivator. Growing evidence suggests that SCAI is a negative regulator of neuronal morphology, whereas MKL2/MRTFB is a positive regulator. The mRNA expression of SCAI is downregulated during brain development, suggesting that a reduction in SCAI contributes to the reduced suppression of SRF-mediated gene induction, thus increasing dendritic complexity and developing neuronal circuits. In the present study, we hypothesized that brain-derived neurotrophic factor (BDNF), which is important for neuronal plasticity and development, might alter SCAI mRNA levels. We therefore investigated the effects of BDNF on SCAI mRNA levels in primary cultured cortical neurons. Furthermore, because alternative splicing generates several SCAI variants in the brain, we measured SCAI variant mRNA after BDNF stimulation. Both SCAI variant 1 and total SCAI mRNA expression levels were downregulated by BDNF. Moreover, the extracellular signal-regulated protein kinase/mitogen-activated protein kinase (ERK/MAPK) pathway was involved in the BDNF-mediated decrease in SCAI mRNA expression. Our findings provide insights into the molecular mechanism underlying a neurotrophic factor switch for the repressive transcriptional complex that includes SCAI.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Neurônios , Humanos , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Neurônios/metabolismo , Regulação da Expressão Gênica , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Invasividade Neoplásica , Células Cultivadas
16.
Genes Cells ; 29(5): 432-437, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38467515

RESUMO

The systemic effects of the artificial sweetener sorbitol on older adult individuals have not been elucidated. We assessed the effects of sorbitol consumption on cognitive and gingival health in a mouse model. Aged mice were fed 5% sorbitol for 3 months before their behavior was assessed, and brain and gingival tissues were collected. Long-term sorbitol consumption inhibited gingival tissue aging in aged mice. However, it caused cognitive decline and decreased brain-derived neurotrophic factor (BDNF) in the hippocampus. Sorbitol consumption did not affect homeostatic function; however, it may exert effects within the brain, particularly in the hippocampus.


Assuntos
Envelhecimento , Cognição , Hipocampo , Sorbitol , Animais , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Sorbitol/farmacologia , Sorbitol/administração & dosagem , Camundongos , Cognição/efeitos dos fármacos , Masculino , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Camundongos Endogâmicos C57BL , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/etiologia
17.
FASEB J ; 38(1): e23351, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38085181

RESUMO

Heart failure (HF) is often accompanied by cognitive impairment (CI). Brain-derived neurotrophic factor (BDNF) deficiency is closely associated with CI. However, the role and mechanism of BDNF in HF with CI is still not fully understood. Here, the case-control study was designed including 25 HF without CI patients (HF-NCI) and 50 HF with CI patients (HF-CI) to investigate the predictive value of BDNF in HF-CI while animal and cell experiments were used for mechanism research. Results found that BDNF levels in serum neuronal-derived exosomes were downregulated in HF-CI patients. There was no significant difference in serum BDNF levels among the two groups. HF rats showed obvious impairment in learning and memory; also, they had reduced thickness and length of postsynaptic density (PSD) and increased synaptic cleft width. Expression of BDNF, TrkB, PSD95, and VGLUT1 was significantly decreased in HF rats brain. In addition, compared with sham rats, amino acids were significantly reduced with no changes in the acetylcholine and monoamine neurotransmitters. Further examination showed that the number of synaptic bifurcations and the expression of BDNF, TrkB, PSD95, and VGLUT1 were all decreased in the neurons that interfered with BDNF-siRNA compared with those in the negative control neurons. Together, our results demonstrated that neuronal-derived exosomal BDNF act as effective biomarkers for prediction of HF-CI. The decrease of BDNF in the brain triggers synaptic structural damage and a decline in amino acid neurotransmitters via the BDNF-TrkB-PSD95/VGLUT1 pathway. This discovery unveils a novel pathological mechanism underlying cognitive impairment following heart failure.


Assuntos
Disfunção Cognitiva , Insuficiência Cardíaca , Humanos , Ratos , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Aminoácidos/metabolismo , Estudos de Casos e Controles , Disfunção Cognitiva/metabolismo , Receptor trkB/genética , Insuficiência Cardíaca/metabolismo , Hipocampo/metabolismo
18.
FASEB J ; 38(1): e23312, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38161282

RESUMO

ProBDNF is the precursor protein of brain-derived neurotrophic factor (BDNF) expressed in the central nervous system and peripheral tissues. Previous studies showed that the blood levels of both proBDNF and p75 neurotrophic receptors (p75NTR) in major depressive disorder (MDD) were increased, but which blood cell types express proBDNF and its receptors is not known. Furthermore, the relationship between proBDNF/p75NTR and inflammatory cytokines in peripheral blood of MDD is unclear. Peripheral blood mononuclear cells (PBMCs) and serum were obtained from depressive patients (n = 32) and normal donors (n = 20). We examined the expression of proBDNF and inflammatory markers and their correlative relationship in patients with major depression. Using flow cytometry analysis, we examined which blood cells express proBDNF and its receptors. Finally, the role of proBDNF/p75NTR signal in inflammatory immune activity of PBMCs was verified in vitro experiments. Inflammatory cytokines in PBMC from MDD patients were increased and correlated with the major depression scores. The levels of IL-1ß and IL-10 were also positively correlated with the major depression scores, while the levels of TNF-α and IL-6 were negatively correlated with the major depression scores. Intriguingly, the levels of sortilin were positively correlated with IL-1ß. Q-PCR and Western blots showed proBDNF, p75NTR, and sortilin levels were significantly increased in PBMCs from MDD patients compared with that from the normal donors. Flow cytometry studies showed that proBDNF and p75NTR were present mainly in CD4+ and CD8+ T cells. The number of proBDNF and p75NTR positive CD4+ and CD8+ T cells from MDD patients was increased and subsequently reversed after therapeutic management. Exogenous proBDNF protein or p75ECD-Fc treatment of cultured PBMC affected the release of inflammatory cytokines in vitro. ProBDNF promoted the expression of inflammatory cytokines, while p75ECD-Fc inhibited the expression of inflammatory cytokines. Given there was an inflammatory response of lymphocytes to proBDNF, it is suggested that proBDNF/p75NTR signaling may upstream inflammatory cytokines in MDD. Our data suggest that proBDNF/p75NTR signaling may not only serve as biomarkers but also may be a potential therapeutic target for MDD.


Assuntos
Transtorno Depressivo Maior , Humanos , Transtorno Depressivo Maior/metabolismo , Leucócitos Mononucleares/metabolismo , Receptores de Fator de Crescimento Neural/genética , Receptores de Fator de Crescimento Neural/metabolismo , Regulação para Cima , Linfócitos T CD8-Positivos/metabolismo , Depressão , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Citocinas/metabolismo
19.
Mol Psychiatry ; 29(3): 760-766, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38177347

RESUMO

Brain-derived neurotrophic factor (BDNF) and its precursor, proBDNF, are known to significantly contribute to brain homeostasis, neuroplasticity, and neuronal remodeling. Although these neurotrophins are thought to have opposing roles, both play a critical part in shaping long-lasting behavioral changes following substance use. In this context, our study sought to explore the implications of these neurotrophins in the pathophysiology of cocaine use disorder (CUD). We conducted a case-control study, which included 28 individuals seeking treatment for CUD and 38 matched healthy participants. We measured peripheral neurotrophin concentrations via an enzyme-linked immunosorbent assay. Additionally, all participants were screened for cocaine-associated pathways (e.g., cocaine intake, craving intensity), along with associated psychopathological data. Our findings highlighted an increased concentration of BDNF and proBDNF in CUD individuals when compared to healthy controls (BDNF: 18092.80 ± 6844.62 vs. 11334.42 ± 5061.85 pg/ml, p < 0.001; proBDNF: 87.03 ± 33.23 vs. 55.70 ± 23.26 ng/ml, p < 0.001). We further corroborated the relationship between neurotrophin levels and CUD using a linear regression model. Nevertheless, there was no significant difference in the proBDNF to BDNF ratio between the two groups. Interestingly, our study also demonstrated the influence of factors like usage of psychotropic medications, history of psychiatric hospitalizations, and psychiatric diagnoses on neurotrophin dynamics. In conclusion, our study underscores the significance of neurotrophin fluctuations in CUD. The observed increase in BDNF and proBDNF levels could play a pivotal role in driving craving and relapse risk. Thus, a nuanced understanding of these neurobiological underpinnings in CUD might contribute to the development of more targeted and effective therapeutic strategies.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Transtornos Relacionados ao Uso de Cocaína , Precursores de Proteínas , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/sangue , Masculino , Feminino , Adulto , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Estudos de Casos e Controles , Precursores de Proteínas/metabolismo , Pessoa de Meia-Idade , Fatores de Crescimento Neural/metabolismo , Cocaína
20.
Mol Psychiatry ; 29(7): 1990-2000, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38351172

RESUMO

Methamphetamine use disorder (MUD) is characterized by loss of control over compulsive drug use. Here, we used a self-administration (SA) model to investigate transcriptional changes associated with the development of early and late compulsivity during contingent footshocks. Punishment initially separated methamphetamine taking rats into always shock-resistant (ASR) rats that continued active lever pressing and shock-sensitive (SS) rats that reduced their lever pressing. At the end of the punishment phase, rats underwent 15 days of forced abstinence at the end of which they were re-introduced to the SA paradigm followed by SA plus contingent shocks. Interestingly, 36 percent of the initial SS rats developed delayed shock-resistance (DSR). Of translational relevance, ASR rats showed more incubation of methamphetamine craving than DSR and always sensitive (AS) rats. RNA sequencing revealed increased striatal Rab37 and Dipk2b mRNA levels that correlated with incubation of methamphetamine craving. Interestingly, Bdnf mRNA levels showed HDAC2-dependent decreased expression in the AS rats. The present SA paradigm should help to elucidate the molecular substrates of early and late addiction-like behaviors.


Assuntos
Corpo Estriado , Fissura , Redes Reguladoras de Genes , Metanfetamina , Punição , Autoadministração , Animais , Metanfetamina/farmacologia , Ratos , Fissura/fisiologia , Masculino , Corpo Estriado/metabolismo , Transtornos Relacionados ao Uso de Anfetaminas/genética , Transtornos Relacionados ao Uso de Anfetaminas/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas rab de Ligação ao GTP/genética , Ratos Sprague-Dawley , Comportamento de Procura de Droga/fisiologia , Comportamento Aditivo/genética , Comportamento Aditivo/metabolismo , Modelos Animais de Doenças
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