RESUMO
Histidine phosphorylation (pHis), occurring on the histidine of substrate proteins, is a hidden phosphoproteome that is poorly characterized in mammals. LHPP (phospholysine phosphohistidine inorganic pyrophosphate phosphatase) is one of the histidine phosphatases and its encoding gene was recently identified as a susceptibility gene for major depressive disorder (MDD). However, little is known about how LHPP or pHis contributes to depression. Here, by using integrative approaches of genetics, behavior and electrophysiology, we observed that LHPP in the medial prefrontal cortex (mPFC) was essential in preventing stress-induced depression-like behaviors. While genetic deletion of LHPP per se failed to affect the mice's depression-like behaviors, it markedly augmented the behaviors upon chronic social defeat stress (CSDS). This augmentation could be recapitulated by the local deletion of LHPP in mPFC. By contrast, overexpressing LHPP in mPFC increased the mice's resilience against CSDS, suggesting a critical role of mPFC LHPP in stress-induced depression. We further found that LHPP deficiency increased the levels of histidine kinases (NME1/2) and global pHis in the cortex, and decreased glutamatergic transmission in mPFC upon CSDS. NME1/2 served as substrates of LHPP, with the Aspartic acid 17 (D17), Threonine 54 (T54), or D214 residue within LHPP being critical for its phosphatase activity. Finally, reintroducing LHPP, but not LHPP phosphatase-dead mutants, into the mPFC of LHPP-deficient mice reversed their behavioral and synaptic deficits upon CSDS. Together, these results demonstrate a critical role of LHPP in regulating stress-related depression and provide novel insight into the pathogenesis of MDD.
Assuntos
Transtorno Depressivo Maior , Animais , Camundongos , Transtorno Depressivo Maior/metabolismo , Depressão , Histidina/metabolismo , Proteínas/metabolismo , Fatores de Risco , Estresse Psicológico/metabolismo , Camundongos Endogâmicos C57BL , Córtex Pré-Frontal/metabolismo , Mamíferos/metabolismoRESUMO
Mutations in some cell adhesion molecules (CAMs) cause abnormal synapse formation and maturation, and serve as one of the potential mechanisms of autism spectrum disorders (ASDs). Recently, DSCAM (Down syndrome cell adhesion molecule) was found to be a high-risk gene for autism. However, it is still unclear how DSCAM contributes to ASD. Here, we show that DSCAM expression was downregulated following synapse maturation, and that DSCAM deficiency caused accelerated dendritic spine maturation during early postnatal development. Mechanistically, the extracellular domain of DSCAM interacts with neuroligin1 (NLGN1) to block the NLGN1-neurexin1ß (NRXN1ß) interaction. DSCAM extracellular domain was able to rescue spine overmaturation in DSCAM knockdown neurons. Precocious spines in DSCAM-deficient mice showed increased glutamatergic transmission in the developing cortex and induced autism-like behaviors, such as social novelty deficits and repetitive behaviors. Thus, DSCAM might be a repressor that prevents premature spine maturation and excessive glutamatergic transmission, and its deficiency could lead to autism-like behaviors. Our study provides new insight into the potential pathophysiological mechanisms of ASDs.SIGNIFICANCE STATEMENTDSCAM is not only associated with Down syndrome but is also a strong autism risk gene based on large-scale sequencing analysis. However, it remains unknown exactly how DSCAM contributes to autism. In mice, either neuron- and astrocyte-specific or pyramidal neuron-specific DSCAM deficiencies resulted in autism-like behaviors and enhanced spatial memory. In addition, DSCAM knockout or knockdown in pyramidal neurons led to increased dendritic spine maturation. Mechanistically, the extracellular domain of DSCAM binds to NLGN1 and inhibits NLGN1-NRXN1ß interaction, which can rescue abnormal spine maturation induced by DSCAM deficiency. Our research demonstrates that DSCAM negatively modulates spine maturation, and that DSCAM deficiency leads to excessive spine maturation and autism-like behaviors, thus providing new insight into a potential pathophysiological mechanism of autism.
Assuntos
Transtorno do Espectro Autista/metabolismo , Moléculas de Adesão Celular/deficiência , Espinhas Dendríticas/metabolismo , Neurogênese/fisiologia , Córtex Somatossensorial/metabolismo , Animais , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Células COS , Moléculas de Adesão Celular/genética , Células Cultivadas , Chlorocebus aethiops , Espinhas Dendríticas/patologia , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/patologiaRESUMO
Extinguishing the previously acquired fear is critical for the adaptation of an organism to the ever-changing environment, a process requiring the engagement of GABAA receptors (GABAARs). GABAARs consist of tens of structurally, pharmacologically, and functionally heterogeneous subtypes. However, the specific roles of these subtypes in fear extinction remain largely unexplored. Here, we observed that in the medial prefrontal cortex (mPFC), a core region for mood regulation, the extrasynaptically situated, δ-subunit-containing GABAARs [GABAA(δ)Rs], had a permissive role in tuning fear extinction in male mice, an effect sharply contrasting to the established but suppressive role by the whole GABAAR family. First, the fear extinction in individual mice was positively correlated with the level of GABAA(δ)R expression and function in their mPFC. Second, knockdown of GABAA(δ)R in mPFC, specifically in its infralimbic (IL) subregion, sufficed to impair the fear extinction in mice. Third, GABAA(δ)R-deficient mice also showed fear extinction deficits, and re-expressing GABAA(δ)Rs in the IL of these mice rescued the impaired extinction. Further mechanistic studies demonstrated that the permissive effect of GABAA(δ)R was associated with its role in enabling the extinction-evoked plastic regulation of neuronal excitability in IL projection neurons. By contrast, GABAA(δ)R had little influence on the extinction-evoked plasticity of glutamatergic transmission in these cells. Altogether, our findings revealed an unconventional and permissive role of extrasynaptic GABAA receptors in fear extinction through a route relying on nonsynaptic plasticity.SIGNIFICANCE STATEMENT The medial prefrontal cortex (mPFC) is one of the kernel brain regions engaged in fear extinction. Previous studies have repetitively shown that the GABAA receptor (GABAAR) family in this region act to suppress fear extinction. However, the roles of specific GABAAR subtypes in mPFC are largely unknown. We observed that the GABAAR-containing δ-subunit [GABAA(δ)R], a subtype of GABAARs exclusively situated in the extrasynaptic membrane and mediating the tonic neuronal inhibition, works oppositely to the whole GABAAR family and promotes (but does not suppress) fear extinction. More interestingly, in striking contrast to the synaptic GABAARs that suppress fear extinction by breaking the extinction-evoked plasticity of glutamatergic transmission, the GABAA(δ)R promotes fear extinction through enabling the plastic regulation of neuronal excitability in the infralimbic subregion of mPFC. Our findings thus reveal an unconventional role of GABAA(δ)R in promoting fear extinction through a route relying on nonsynaptic plasticity.
Assuntos
Extinção Psicológica , Medo , Animais , Medo/fisiologia , Masculino , Camundongos , Neurônios/metabolismo , Plásticos/metabolismo , Plásticos/farmacologia , Córtex Pré-Frontal/fisiologia , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/farmacologiaRESUMO
The GABAB receptor (GABABR) agonist baclofen has been used to treat alcohol and several other substance use disorders (AUD/SUD), yet its underlying neural mechanism remains unclear. The present study aimed to investigate cortical GABABR dynamics following chronic alcohol exposure. Ex vivo brain slice recordings from mice chronically exposed to alcohol revealed a reduction in GABABR-mediated currents, as well as a decrease of GABAB1/2R and G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2) activities in the motor cortex. Moreover, our data indicated that these alterations could be attributed to dephosphorylation at the site of serine 783 (ser-783) in GABAB2 subunit, which regulates the surface expression of GABABR. Furthermore, a human study using paired-pulse-transcranial magnetic stimulation (TMS) analysis further demonstrated a reduced cortical inhibition mediated by GABABR in patients with AUD. Our findings provide the first evidence that chronic alcohol exposure is associated with significantly impaired cortical GABABR function. The ability to promote GABABR signaling may account for the therapeutic efficacy of baclofen in AUD.
Assuntos
Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G , Córtex Motor , Animais , Baclofeno/farmacologia , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Humanos , Camundongos , Receptores de GABA-B/metabolismo , Transdução de SinaisRESUMO
Stress alters the level of reward evaluation and seeking. However, the neural circuitry mechanisms underlying stress induced effects on natural reward seeking remain unclear. Here we report a septal-accumbens pathway that mediates the effects of acute stress on reward seeking suppression. We first established the sucrose oral self-administration paradigm and measured the effects of acute stress on reward seeking behavior after 21 days of abstinence. Both forced swimming stress and foot shock stress significantly suppressed the natural reward seeking. Among a variety of brain regions, intermediolateral septum (LSi) appear as a strong stress-responsive area containing abundant c-Fos positive cells; chemogenetic inactivation of LSi reinstated the reward seeking behavior. To elucidate the downstream targets receiving LSi projections, we combined pathway-specific retro-labeling and chemogenetic manipulation to confirm the involvement of LSi-nucleus accumbens (NAc) rather than the Ventral tegmental area (VTA) in mediating the observed behavioral responses. In conclusion, the septal-accumbal projection constitute a discrete circuit dictating the stress evoked alterations on reward seeking and may implicate in treatment of stress induced anhedonia.
Assuntos
Condicionamento Operante , Núcleo Accumbens , Condicionamento Operante/fisiologia , Recompensa , Sacarose/farmacologia , Área Tegmentar VentralRESUMO
Depression and anxiety disorders are the two most prevalent psychiatric diseases that affect hundreds of millions of individuals worldwide. Understanding the etiology and related mechanisms is of great importance and might yield new therapeutic strategies to treat these diseases effectively. During the past decades, a growing number of studies have pointed out the importance of the stress-induced inflammatory response in the amygdala, a kernel region for processing emotional stimuli, as a potentially critical contributor to the pathophysiology of depression and anxiety disorders. In this review, we first summarized the recent progress from both animal and human studies toward understanding the causal link between stress-induced inflammation and depression and anxiety disorders, with particular emphasis on findings showing the effect of inflammation on the functional changes in neurons in the amygdala, at levels ranging from molecular signaling, cellular function, synaptic plasticity, and the neural circuit to behavior, as well as their contributions to the pathology of inflammation-related depression and anxiety disorders. Finally, we concluded by discussing some of the difficulties surrounding the current research and propose some issues worth future study in this field.
Assuntos
Tonsila do Cerebelo , Depressão , Animais , Ansiedade/etiologia , Transtornos de Ansiedade/etiologia , Depressão/etiologia , Emoções , Humanos , InflamaçãoRESUMO
Increasing evidence indicates that excessive inflammatory responses play a crucial role in the pathophysiology of psychiatric diseases, including depression and anxiety disorders. The dysfunctional neural plasticity in amygdala has long been proposed as the vital cause for the progression of psychiatric disorders. However, the effect of neuroinflammation on the functional changes of the amygdala remains largely unknown. Here, by using a mouse model of inflammation induced by lipopolysaccharide (LPS) injection, we investigated the effect of LPS-induced neuroinflammation on the synaptic and non-synaptic plasticity in basolateral amygdala (BLA) projection neurons (PNs) and their contribution to the LPS-induced anxiety- and depressive-like behavior. The results showed that LPS treatment led to the activation of microglia and production of proinflammatory cytokines in the BLA. Furthermore, LPS treatment increased excitatory but not inhibitory synaptic transmission due to the enhanced presynaptic glutamate release, thus leading to the shift of excitatory/inhibitory balance towards excitatory. In addition, the intrinsic neuronal excitability of BLA PNs was also increased by LPS treatment through the loss of expression and function of small-conductance, calcium-activated potassium channel. Chronic fluoxetine pretreatment significantly prevented these neurophysiological changes induced by LPS, and alleviated anxiety and depressive-like behavior, indicating that LPS-induced neuronal dysregulation of BLA PNs may contribute to the development of psychiatry disorders. Collectively, these findings provide evidence that dysregulation of synaptic and non-synaptic transmission in the BLA PNs may account for neuroinflammation-induced anxiety- and depressive-like behavior.
Assuntos
Complexo Nuclear Basolateral da Amígdala , Tonsila do Cerebelo , Ansiedade , Transtornos de Ansiedade , Humanos , Plasticidade NeuronalRESUMO
Neurotrophic factor NRG1 and its receptor ErbB4 play a role in GABAergic circuit assembly during development. ErbB4 null mice possess fewer interneurons, have decreased GABA release, and show impaired behavior in various paradigms. In addition, NRG1 and ErbB4 have also been implicated in regulating GABAergic transmission and plasticity in matured brains. However, current ErbB4 mutant strains are unable to determine whether phenotypes in adult mutant mice result from abnormal neural development. This important question, a glaring gap in understanding NRG1-ErbB4 function, was addressed by using two strains of mice with temporal control of ErbB4 deletion and expression, respectively. We found that ErbB4 deletion in adult mice impaired behavior and GABA release but had no effect on neuron numbers and morphology. On the other hand, some deficits due to the ErbB4 null mutation during development were alleviated by restoring ErbB4 expression at the adult stage. Together, our results indicate a critical role of NRG1-ErbB4 signaling in GABAergic transmission and behavior in adulthood and suggest that restoring NRG1-ErbB4 signaling at the postdevelopmental stage might benefit relevant brain disorders.
Assuntos
Comportamento Animal , Encéfalo/patologia , Interneurônios/patologia , Neuregulina-1/metabolismo , Receptor ErbB-4/fisiologia , Sinapses/fisiologia , Transmissão Sináptica , Animais , Encéfalo/metabolismo , Interneurônios/metabolismo , Camundongos , Camundongos Knockout , Neuregulina-1/genética , Transdução de Sinais , Ácido gama-Aminobutírico/metabolismoRESUMO
Neuregulin3 (NRG3) is a growth factor of the neuregulin (NRG) family and a risk gene of various severe mental illnesses including schizophrenia, bipolar disorders, and major depression. However, the physiological function of NRG3 remains poorly understood. Here we show that loss of Nrg3 in GFAP-Nrg3f/f mice increased glutamatergic transmission, but had no effect on GABAergic transmission. These phenotypes were observed in Nex-Nrg3f/f mice, where Nrg3 was specifically knocked out in pyramidal neurons, indicating that Nrg3 regulates glutamatergic transmission by a cell-autonomous mechanism. Consequently, in the absence of Nrg3 in pyramidal neurons, mutant mice displayed various behavioral deficits related to mental illnesses. We show that the Nrg3 mutation decreased paired-pulse facilitation, increased decay of NMDAR currents when treated with MK801, and increased minimal stimulation-elicited response, providing evidence that the Nrg3 mutation increases glutamate release probability. Notably, Nrg3 is a presynaptic protein that regulates the SNARE-complex assembly. Finally, increased Nrg3 levels, as observed in patients with severe mental illnesses, suppressed glutamatergic transmission. Together, these observations indicate that, unlike the prototype Nrg1, the effect of which is mediated by activating ErbB4 in interneurons, Nrg3 is critical in controlling glutamatergic transmission by regulating the SNARE complex at the presynaptic terminals, identifying a function of Nrg3 and revealing a pathophysiological mechanism for hypofunction of the glutamatergic pathway in Nrg3-related severe mental illnesses.
Assuntos
Ácido Glutâmico/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas SNARE/metabolismo , Animais , Comportamento Animal/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Transtornos Mentais/genética , Camundongos , Camundongos Transgênicos , Neurregulinas , Células Piramidais/metabolismoRESUMO
Gliomas are malignant tumors with strong invasiveness. The current treatment strategy is surgical treatment assisted by a variety of radiotherapies, chemotherapies and immunotherapies. However, the curative efficacy is limited. Adrenergic receptor (AR) is an important stress hormone receptor, which is highly involved in the regulation of the tumorigenesis and progression of various tumors by activating different downstream signal transduction pathways. Recent studies have shown that AR is dysregulated in glioma cells and tissues, and plays an important role in a series of biological behaviors such as tumorigenesis, invasion and metastasis of glioma. This article reviews the research progress of AR in the field of glioma in recent years, which provides a theoretical basis for the prevention and treatment of glioma targeting the AR.
Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , Receptores Adrenérgicos/fisiologia , Transdução de Sinais , Carcinogênese , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica , Metástase NeoplásicaRESUMO
Coloboma, heart defect, atresia choanae, retarded growth and development, genital hypoplasia, ear anomalies/deafness (CHARGE) syndrome is a congenital disorder affecting multiple organs and mainly caused by mutations in CHD7, a gene encoding a chromatin-remodeling protein. Immunodeficiency and reduced T cells have been noted in CHARGE syndrome. However, the mechanisms underlying T lymphopenia are largely unexplored. Herein, we observed dramatic decrease of T cells in both chd7knockdown and knockout zebrafish embryos. Unexpectedly, hematopoietic stem and progenitor cells and, particularly, lymphoid progenitor cells were increased peripherally in nonthymic areas in chd7-deficient embryos, unlikely to contribute to the T-cell decrease. Further analysis demonstrated that both the organogenesis and homing function of the thymus were seriously impaired. Chd7 might regulate thymus organogenesis through modulating the development of both neural crest cell-derived mesenchyme and pharyngeal endoderm-derived thymic epithelial cells. The expression of foxn1, a central regulator of thymic epithelium, was remarkably down-regulated in the pharyngeal region in chd7-deficient embryos. Moreover, the T-cell reduction in chd7-deficient embryos was partially rescued by overexpressing foxn1, suggesting that restoring thymic epithelium may be a potential therapeutic strategy for treating immunodeficiency in CHARGE syndrome. Collectively, the results indicated that chd7 was critical for thymic development and T-lymphopenia in CHARGE syndrome may be mainly attributed to the defects of thymic organogenesis. The current finding may benefit the diagnosis and therapy of T lymphopenia and immunodeficiency in CHARGE syndrome.
Assuntos
DNA Helicases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Organogênese , Linfócitos T/citologia , Timo/citologia , Timo/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Sequência de Bases , Proteínas Morfogenéticas Ósseas/metabolismo , Região Branquial/efeitos dos fármacos , Região Branquial/embriologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quimiocinas/metabolismo , DNA Helicases/deficiência , Proteínas de Ligação a DNA/deficiência , Embrião não Mamífero/metabolismo , Células Epiteliais/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Morfolinos/farmacologia , Mutação/genética , Crista Neural/patologia , Fenótipo , Transdução de Sinais , Peixe-Zebra/embriologia , Proteínas de Peixe-Zebra/deficiênciaRESUMO
The role of δ subunit-containing GABAA receptor (GABAA(δ)R) in fear generalization is uncertain. Here, by using mice with or without genetic deletion of GABAA(δ)R and using protocols in which the conditioned tone stimuli were cross presented with different nonconditioned stimuli, we observed that when the two tone stimuli were largely similar, both genotypes froze similarly to either of them. However, when they differed markedly, the knockout mice froze much more than their wild-type littermates to the nonconditioned but not conditioned stimuli. Thus, GABAA(δ)R may prevent inappropriate fear generalization when the incoming stimuli differ clearly from the learned threat.
Assuntos
Medo/fisiologia , Generalização Psicológica/fisiologia , Receptores de GABA-A/metabolismo , Estimulação Acústica , Animais , Ansiedade/metabolismo , Percepção Auditiva/fisiologia , Comportamento Exploratório/fisiologia , Reação de Congelamento Cataléptica/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testes Neuropsicológicos , Receptores de GABA-A/genéticaRESUMO
Bisphenol A (BPA), one of the most common environmental endocrine disruptors, has been recognized to have wide adverse effects on the brain development and behavior. These adversities are related to its ability to bind estrogen receptor (ER) with subsequent alteration of its expression in the target areas. However, very little is known about whether BPA exposure also affects ER phosphorylation and its translocation to nucleus during postnatal development, two critical steps for its function. Here, we found that during development from postnatal day 7 (P7) to P21, the alpha subtype of ER (ERα) in the hippocampus of male rats experienced remarkable alterations in terms of its expression, phosphorylation and translocation to nucleus. Exposure to low level of BPA had bidirectional, development-dependent effects on the expression of ERα mRNA and protein, but decreased ERα phosphorylation and impaired its translocation to nucleus throughout the period investigated. Treatment with low dose of ICI 182,780 (ICI), an ER antagonist to block the binding of ER with BPA, reversed the altered ERα following BPA exposure, highlighting critical involvement of ER. Moreover, ICI treatment rescued the hippocampus-dependent behavioral deficits in the adult rats experiencing early-life BPA exposure. Overall, our results indicate that BPA interferes with the ERα signaling in the developing hippocampus in an ER-dependent manner, which may underlie its adverse behavioral and cognitive outcomes in adult animals.
Assuntos
Compostos Benzidrílicos/toxicidade , Receptor alfa de Estrogênio/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/crescimento & desenvolvimento , Fenóis/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Animais , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas do Receptor de Estrogênio/farmacologia , Receptor alfa de Estrogênio/antagonistas & inibidores , Feminino , Fulvestranto , Hipocampo/metabolismo , Masculino , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Fosforilação , Gravidez , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Memória Espacial/efeitos dos fármacos , Memória Espacial/fisiologiaRESUMO
Understanding how distinct functional circuits are coordinated to fine-tune mood and behavior is of fundamental importance. Here, we observe that within the dense projections from basolateral amygdala (BLA) to bed nucleus of stria terminalis (BNST), there are two functionally opposing pathways orchestrated to enable contextually appropriate expression of anxiety-like behaviors in male mice. Specifically, the anterior BLA neurons predominantly innervate the anterodorsal BNST (adBNST), while their posterior counterparts send massive fibers to oval BNST (ovBNST) with moderate to adBNST. Optogenetic activation of the anterior and posterior BLA inputs oppositely regulated the activity of adBNST neurons and anxiety-like behaviors, via disengaging and engaging the inhibitory ovBNST-to-adBNST microcircuit, respectively. Importantly, the two pathways exhibited synchronized but opposite responses to both anxiolytic and anxiogenic stimuli, partially due to their mutual inhibition within BLA and the different inputs they receive. These findings reveal synergistic interactions between two BLA-to-BNST pathways for appropriate anxiety expression with ongoing environmental demands.
Assuntos
Ansiedade , Complexo Nuclear Basolateral da Amígdala , Optogenética , Núcleos Septais , Animais , Masculino , Núcleos Septais/fisiologia , Núcleos Septais/metabolismo , Complexo Nuclear Basolateral da Amígdala/metabolismo , Complexo Nuclear Basolateral da Amígdala/fisiologia , Camundongos , Comportamento Animal/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologiaRESUMO
BACKGROUND: Chronic stress-induced neuroinflammation plays a pivotal role in the development and exacerbation of mental disorders, such as anxiety and depression. Dimethyl Fumarate (DMF), an effective therapeutic agent approved for the treatment of multiple sclerosis, has been widely reported to display anti-inflammatory and anti-oxidative effects. However, the impact of DMF on chronic stress-induced anxiety disorders and the exact underlying mechanisms remain largely unknown. METHODS: We established a mouse model of chronic social defeat stress (CSDS). DMF was administered orally 1 h before daily stress session for 10 days in CSDS + DMF group. qRT-PCR and western blotting were used to analyze mRNA and protein expression of NLRP3, Caspase-1 and IL-1ß. Immunofluorescence staining was carried out to detect the expression of Iba 1 and c-fos positive cells as well as morphological change of Iba 1+ microglia. Whole-cell patch-clamp recording was applied to evaluate synaptic transmission and intrinsic excitability of neurons. RESULTS: DMF treatment significantly alleviated CSDS-induced anxiety-like behaviors in mice. Mechanistically, DMF treatment prevented CSDS-induced neuroinflammation by inhibiting the activation of microglia and NLRP3/Caspase-1/IL-1ß signaling pathway in basolateral amygdala (BLA), a brain region important for emotional processing. Furthermore, DMF treatment effectively reversed the CSDS-caused disruption of excitatory and inhibitory synaptic transmission balance, as well as the increased intrinsic excitability of BLA neurons. CONCLUSIONS: Our findings provide new evidence that DMF may exert anxiolytic effect by preventing CSDS-induced activation of NLRP3/Caspase-1/IL-1ß signaling pathway and alleviating hyperactivity of BLA neurons.
Assuntos
Ansiedade , Fumarato de Dimetilo , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR , Neurônios , Estresse Psicológico , Animais , Fumarato de Dimetilo/farmacologia , Fumarato de Dimetilo/uso terapêutico , Masculino , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/imunologia , Camundongos , Ansiedade/tratamento farmacológico , Neurônios/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/metabolismo , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/imunologia , Modelos Animais de Doenças , Interleucina-1beta/metabolismo , Microglia/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Caspase 1/metabolismo , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/farmacologia , Transdução de Sinais/efeitos dos fármacos , Derrota SocialRESUMO
Myeloid-derived suppressor cells (MDSC) are a population of heterogeneous immune cells that are involved in precancerous conditions and neoplasms. The autonomic nervous system (ANS), which is composed of the sympathetic nervous system and the parasympathetic nervous system, is an important component of the tumor microenvironment that responds to changes in the internal and external environment mainly through adrenergic and cholinergic signaling. An abnormal increase of autonomic nerve density has been associated with cancer progression. As we discuss in this review, growing evidence indicates that sympathetic and parasympathetic signals directly affect the expansion, mobilization, and redistribution of MDSCs. Dysregulated autonomic signaling recruits MDSCs to form an immunosuppressive microenvironment in chronically inflamed tissues, resulting in abnormal proliferation and differentiation of adult stem cells. The two components of the ANS may also be responsible for the seemingly contradictory behaviors of MDSCs. Elucidating the underlying mechanisms has the potential to provide more insights into the complex roles of MDSCs in tumor development and lay the foundation for the development of novel MDSC-targeted anticancer strategies.
Assuntos
Sistema Nervoso Autônomo , Células Supressoras Mieloides , Neoplasias , Microambiente Tumoral , Humanos , Neoplasias/imunologia , Sistema Nervoso Autônomo/fisiopatologia , Células Supressoras Mieloides/imunologia , Animais , Transdução de SinaisRESUMO
Epigenetic mechanisms bridge genetic and environmental factors that contribute to the pathogenesis of major depression disorder (MDD). However, the cellular specificity and sensitivity of environmental stress on brain epitranscriptomics and its impact on depression remain unclear. Here, we found that ALKBH5, an RNA demethylase of N6-methyladenosine (m6A), was increased in MDD patients' blood and depression models. ALKBH5 in astrocytes was more sensitive to stress than that in neurons and endothelial cells. Selective deletion of ALKBH5 in astrocytes, but not in neurons and endothelial cells, produced antidepressant-like behaviors. Astrocytic ALKBH5 in the mPFC regulated depression-related behaviors bidirectionally. Meanwhile, ALKBH5 modulated glutamate transporter-1 (GLT-1) m6A modification and increased the expression of GLT-1 in astrocytes. ALKBH5 astrocyte-specific knockout preserved stress-induced disruption of glutamatergic synaptic transmission, neuronal atrophy and defective Ca2+ activity. Moreover, enhanced m6A modification with S-adenosylmethionine (SAMe) produced antidepressant-like effects. Our findings indicate that astrocytic epitranscriptomics contribute to depressive-like behaviors and that astrocytic ALKBH5 may be a therapeutic target for depression.
Assuntos
Homólogo AlkB 5 da RNA Desmetilase , Astrócitos , Transtorno Depressivo Maior , Camundongos Knockout , Animais , Astrócitos/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/metabolismo , Homólogo AlkB 5 da RNA Desmetilase/genética , Camundongos , Humanos , Transtorno Depressivo Maior/metabolismo , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/patologia , Masculino , Feminino , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Estresse Psicológico/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Transportador 2 de Aminoácido Excitatório/genética , Comportamento Animal , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Depressão/metabolismo , Depressão/genética , Adulto , Transmissão Sináptica , Pessoa de Meia-IdadeRESUMO
Anxiety is a normal and transitory emotional state that allows the organisms to cope well with the real or perceived threats, while excessive or prolonged anxiety is a key characteristic of anxiety disorders. We have recently revealed that prolonged anxiety induced by chronic stress is associated with the circuit-varying dysfunction of basolateral amygdala projection neurons (BLA PNs). However, it is not yet known whether similar mechanisms also emerge for acute stress-induced, short-lasting increase of anxiety. Here, using a mouse model of acute restraint stress (ARS), we found that ARS mice showed increased anxiety-like behavior at 2 h but not 24 h after stress, and this effect was accompanied by a transient increase of the activity of BLA PNs. Specifically, ex vivo patch-clamp recordings revealed that the increased BLA neuronal activity did not differ among the distinct BLA neuronal populations, regardless of their projection targets being the dorsomedial prefrontal cortex (dmPFC) or elsewhere. We further demonstrated that such effects were mainly mediated by the enhanced presynaptic glutamate release in dmPFC-to-BLA synapses but not lateral amygdala-to-BLA ones. Furthermore, while optogenetically weakening the presynaptic glutamate release in dmPFC-to-BLA synapses ameliorated ARS-induced anxiety-like behavior, strengthening the release increased in unstressed mice. Together, these findings suggest that acute stress causes short-lasting increase in anxiety-like behavior by facilitating synaptic transmission from the prefrontal cortex to the amygdala in a circuit-independent fashion.
Assuntos
Complexo Nuclear Basolateral da Amígdala , Humanos , Complexo Nuclear Basolateral da Amígdala/fisiologia , Córtex Pré-Frontal/fisiologia , Ansiedade/etiologia , Transtornos de Ansiedade , GlutamatosRESUMO
One of the most sought-after topics in neuroscience is to understand how the environment regulates the activity and function of neural circuitry and subsequently influences relevant behaviors. In response to alterations in the environment, the neural circuits undergo adaptive changes ranging from gene expression changes to altered cellular function. Performing sequencing of the transcriptome involved in these behavior-related circuits will provide clues to accurately dissect the detailed mechanisms of related behavior. Here, we describe methods for marking and collecting the ventral hippocampus-projecting basolateral amygdala neurons, which have been repeatedly implicated in regulation of anxiety-like behavior, and subsequently constructing a library ready for sequencing. Specifically, the reported approaches include adeno-associated virus injection, acute brain slice isolation, cell suspension preparation, cell extraction, and cDNA library construction. By utilizing the techniques described here, researchers can comprehensively investigate the transcriptional levels of neural clusters embedded in particular circuits and discover potential pathogenic and therapeutic targets for behavior-relevant disorders. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Tagging of behavior-related neural circuits Basic Protocol 2: Isolation and capture of fluorescent-positive cells Basic Protocol 3: Foundation of sequencing library.