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1.
Cell ; 184(3): 709-722.e13, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33482084

RESUMO

Neural stem cells (NSCs) in the adult brain transit from the quiescent state to proliferation to produce new neurons. The mechanisms regulating this transition in freely behaving animals are, however, poorly understood. We customized in vivo imaging protocols to follow NSCs for several days up to months, observing their activation kinetics in freely behaving mice. Strikingly, NSC division is more frequent during daylight and is inhibited by darkness-induced melatonin signaling. The inhibition of melatonin receptors affected intracellular Ca2+ dynamics and promoted NSC activation. We further discovered a Ca2+ signature of quiescent versus activated NSCs and showed that several microenvironmental signals converge on intracellular Ca2+ pathways to regulate NSC quiescence and activation. In vivo NSC-specific optogenetic modulation of Ca2+ fluxes to mimic quiescent-state-like Ca2+ dynamics in freely behaving mice blocked NSC activation and maintained their quiescence, pointing to the regulatory mechanisms mediating NSC activation in freely behaving animals.


Assuntos
Células-Tronco Adultas/metabolismo , Cálcio/metabolismo , Ritmo Circadiano , Espaço Intracelular/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Comportamento Animal/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ritmo Circadiano/efeitos dos fármacos , Citosol/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Melatonina/metabolismo , Camundongos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Optogenética , Transdução de Sinais/efeitos dos fármacos , Triptaminas/farmacologia
2.
Cell ; 179(7): 1483-1498.e22, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31813625

RESUMO

Metabolism has been shown to control peripheral immunity, but little is known about its role in central nervous system (CNS) inflammation. Through a combination of proteomic, metabolomic, transcriptomic, and perturbation studies, we found that sphingolipid metabolism in astrocytes triggers the interaction of the C2 domain in cytosolic phospholipase A2 (cPLA2) with the CARD domain in mitochondrial antiviral signaling protein (MAVS), boosting NF-κB-driven transcriptional programs that promote CNS inflammation in experimental autoimmune encephalomyelitis (EAE) and, potentially, multiple sclerosis. cPLA2 recruitment to MAVS also disrupts MAVS-hexokinase 2 (HK2) interactions, decreasing HK enzymatic activity and the production of lactate involved in the metabolic support of neurons. Miglustat, a drug used to treat Gaucher and Niemann-Pick disease, suppresses astrocyte pathogenic activities and ameliorates EAE. Collectively, these findings define a novel immunometabolic mechanism that drives pro-inflammatory astrocyte activities, outlines a new role for MAVS in CNS inflammation, and identifies candidate targets for therapeutic intervention.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Astrócitos/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Fosfolipases A2 Secretórias/metabolismo , 1-Desoxinojirimicina/análogos & derivados , 1-Desoxinojirimicina/farmacologia , 1-Desoxinojirimicina/uso terapêutico , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Encefalomielite Autoimune Experimental/tratamento farmacológico , Feminino , Hexoquinase/metabolismo , Humanos , Ácido Láctico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Fosfolipases A2 Secretórias/genética
3.
Cell ; 174(1): 59-71.e14, 2018 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-29804835

RESUMO

Astrocytes respond to neuronal activity and were shown to be necessary for plasticity and memory. To test whether astrocytic activity is also sufficient to generate synaptic potentiation and enhance memory, we expressed the Gq-coupled receptor hM3Dq in CA1 astrocytes, allowing their activation by a designer drug. We discovered that astrocytic activation is not only necessary for synaptic plasticity, but also sufficient to induce NMDA-dependent de novo long-term potentiation in the hippocampus that persisted after astrocytic activation ceased. In vivo, astrocytic activation enhanced memory allocation; i.e., it increased neuronal activity in a task-specific way only when coupled with learning, but not in home-caged mice. Furthermore, astrocytic activation using either a chemogenetic or an optogenetic tool during acquisition resulted in memory recall enhancement on the following day. Conversely, directly increasing neuronal activity resulted in dramatic memory impairment. Our findings that astrocytes induce plasticity and enhance memory may have important clinical implications for cognitive augmentation treatments.


Assuntos
Potenciação de Longa Duração , Memória , Neurônios/metabolismo , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Cálcio/metabolismo , Clozapina/análogos & derivados , Clozapina/farmacologia , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Hipocampo/citologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , N-Metilaspartato/farmacologia , Neurônios/efeitos dos fármacos , Optogenética , Técnicas de Patch-Clamp , Proteínas Proto-Oncogênicas c-fos/metabolismo , Estresse Psicológico , Potenciais Sinápticos/efeitos dos fármacos
4.
Nature ; 583(7817): 603-608, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32641832

RESUMO

Astrocytes take up glucose from the bloodstream to provide energy to the brain, thereby allowing neuronal activity and behavioural responses1-5. By contrast, astrocytes are under neuronal control through specific neurotransmitter receptors5-7. However, whether the activation of astroglial receptors can directly regulate cellular glucose metabolism to eventually modulate behavioural responses is unclear. Here we show that activation of mouse astroglial type-1 cannabinoid receptors associated with mitochondrial membranes (mtCB1) hampers the metabolism of glucose and the production of lactate in the brain, resulting in altered neuronal functions and, in turn, impaired behavioural responses in social interaction assays. Specifically, activation of astroglial mtCB1 receptors reduces the phosphorylation of the mitochondrial complex I subunit NDUFS4, which decreases the stability and activity of complex I. This leads to a reduction in the generation of reactive oxygen species by astrocytes and affects the glycolytic production of lactate through the hypoxia-inducible factor 1 pathway, eventually resulting in neuronal redox stress and impairment of behavioural responses in social interaction assays. Genetic and pharmacological correction of each of these effects abolishes the effect of cannabinoid treatment on the observed behaviour. These findings suggest that mtCB1 receptor signalling can directly regulate astroglial glucose metabolism to fine-tune neuronal activity and behaviour in mice.


Assuntos
Astrócitos/metabolismo , Metabolismo Energético , Glucose/metabolismo , Mitocôndrias/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Agonistas de Receptores de Canabinoides/farmacologia , Células Cultivadas , Dronabinol/farmacologia , Complexo I de Transporte de Elétrons/química , Complexo I de Transporte de Elétrons/metabolismo , Metabolismo Energético/efeitos dos fármacos , Glicólise/efeitos dos fármacos , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Ácido Láctico/metabolismo , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Oxirredução , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Receptor CB1 de Canabinoide/agonistas , Comportamento Social
5.
J Neurosci ; 44(34)2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-38926088

RESUMO

Current anesthetic theory is mostly based on neurons and/or neuronal circuits. A role for astrocytes also has been shown in promoting recovery from volatile anesthesia, while the exact modulatory mechanism and/or the molecular target in astrocytes is still unknown. In this study by animal models in male mice and electrophysiological recordings in vivo and in vitro, we found that activating astrocytes of the paraventricular thalamus (PVT) and/or knocking down PVT astrocytic Kir4.1 promoted the consciousness recovery from sevoflurane anesthesia. Single-cell RNA sequencing of the PVT reveals two distinct cellular subtypes of glutamatergic neurons: PVT GRM and PVT ChAT neurons. Patch-clamp recording results proved astrocytic Kir4.1-mediated modulation of sevoflurane on the PVT mainly worked on PVT ChAT neurons, which projected mainly to the mPFC. In summary, our findings support the novel conception that there is a specific PVT→prefrontal cortex projection involved in consciousness recovery from sevoflurane anesthesia, which is mediated by the inhibition of sevoflurane on PVT astrocytic Kir4.1 conductance.


Assuntos
Astrócitos , Estado de Consciência , Núcleos da Linha Média do Tálamo , Canais de Potássio Corretores do Fluxo de Internalização , Sevoflurano , Animais , Astrócitos/fisiologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Masculino , Camundongos , Sevoflurano/farmacologia , Estado de Consciência/fisiologia , Estado de Consciência/efeitos dos fármacos , Núcleos da Linha Média do Tálamo/fisiologia , Núcleos da Linha Média do Tálamo/efeitos dos fármacos , Núcleos da Linha Média do Tálamo/citologia , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Camundongos Endogâmicos C57BL , Anestésicos Inalatórios/farmacologia , Vias Neurais/fisiologia , Vias Neurais/efeitos dos fármacos , Neurônios/fisiologia , Neurônios/efeitos dos fármacos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/efeitos dos fármacos , Lobo Frontal/fisiologia , Lobo Frontal/efeitos dos fármacos , Período de Recuperação da Anestesia
6.
FASEB J ; 38(13): e23781, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38941212

RESUMO

Reactive astrocytes are important pathophysiologically and synthesize neurosteroids. We observed that LPS increased immunoreactive TLR4 and key steroidogenic enzymes in cortical astrocytes of rats and investigated whether corticosteroids are produced and mediate astrocytic TLR4-dependent innate immune responses. We found that LPS increased steroidogenic acute regulatory protein (StAR) and StAR-dependent aldosterone production in purified astrocytes. Both increases were blocked by the TLR4 antagonist TAK242. LPS also increased 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) and corticosterone production, and both were prevented by TAK242 and by siRNAs against 11ß-HSD1, StAR, or aldosterone synthase (CYP11B2). Knockdown of 11ß-HSD1, StAR, or CYP11B2 or blocking either mineralocorticoid receptors (MR) or glucocorticoid receptors (GR) prevented dephosphorylation of p-Ser9GSK-3ß, activation of NF-κB, and the GSK-3ß-dependent increases of C3, IL-1ß, and TNF-α caused by LPS. Exogenous aldosterone mimicked the MR- and GSK-3ß-dependent pro-inflammatory effects of LPS in astrocytes, but corticosterone did not. Supernatants from astrocytes treated with LPS reduced MAP2 and viability of cultured neurons except when astrocytic StAR or MR was inhibited. In adrenalectomized rats, intracerebroventricular injection of LPS increased astrocytic TLR4, StAR, CYP11B2, and 11ß-HSD1, NF-κB, C3 and IL-1ß, decreased astrocytic p-Ser9GSK-3ß in the cortex and was neurotoxic, except when spironolactone was co-injected, consistent with the in vitro results. LPS also activated NF-κB in some NeuN+ and CD11b+ cells in the cortex, and these effects were prevented by spironolactone. We conclude that intracrine aldosterone may be involved in the TLR4-dependent innate immune responses of astrocytes and can trigger paracrine effects by activating astrocytic MR/GSK-3ß/NF-κB signaling.


Assuntos
Astrócitos , Glicogênio Sintase Quinase 3 beta , Imunidade Inata , Lipopolissacarídeos , Receptor 4 Toll-Like , Animais , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo , Imunidade Inata/efeitos dos fármacos , Ratos , Glicogênio Sintase Quinase 3 beta/metabolismo , Lipopolissacarídeos/farmacologia , Corticosteroides/farmacologia , Ratos Sprague-Dawley , Células Cultivadas , Receptores de Mineralocorticoides/metabolismo , Aldosterona/metabolismo , Aldosterona/farmacologia , Masculino , NF-kappa B/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Corticosterona/farmacologia
7.
FASEB J ; 38(15): e23872, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39126272

RESUMO

Paclitaxel is among the most active chemotherapy drugs for the aggressive triple negative breast cancer (TNBC). Unfortunately, it often induces painful peripheral neuropathy (CIPN), a major debilitating side effect. Here we demonstrate that in naive and breast tumor-bearing immunocompetent mice, a clinically relevant dose of FTY720/Fingolimod that targets sphingosine-1-phosphate receptor 1 (S1PR1), alleviated paclitaxel-induced neuropathic pain. FTY720 also significantly attenuated paclitaxel-stimulated glial fibrillary acidic protein (GFAP), a marker for activated astrocytes, and expression of the astrocyte-secreted synaptogenic protein Sparcl1/Hevin, a key regulator of synapse formation. Notably, the formation of excitatory synapses containing VGluT2 in the spinal cord dorsal horn induced by paclitaxel was also inhibited by FTY720 treatment, supporting the involvement of astrocytes and Sparcl1 in CIPN. Furthermore, in this TNBC mouse model that mimics human breast cancer, FTY720 administration also enhanced the anti-tumor effects of paclitaxel, leading to reduced tumor progression and lung metastasis. Taken together, our findings suggest that targeting the S1P/S1PR1 axis with FTY720 is a multipronged approach that holds promise as a therapeutic strategy for alleviating both CIPN and enhancing the efficacy of chemotherapy in TNBC treatment.


Assuntos
Cloridrato de Fingolimode , Neuralgia , Paclitaxel , Animais , Cloridrato de Fingolimode/farmacologia , Paclitaxel/farmacologia , Neuralgia/induzido quimicamente , Neuralgia/tratamento farmacológico , Neuralgia/metabolismo , Neuralgia/patologia , Camundongos , Feminino , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Proteínas da Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/genética , Linhagem Celular Tumoral , Receptores de Esfingosina-1-Fosfato/metabolismo , Humanos , Progressão da Doença , Antineoplásicos Fitogênicos/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Proteína Glial Fibrilar Ácida/genética
8.
Mol Psychiatry ; 29(3): 820-834, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38238549

RESUMO

Cocaine affects both cerebral blood vessels and neuronal activity in brain. Cocaine can also disrupt astrocytes, which modulate neurovascular coupling-a process that regulates cerebral hemodynamics in response to neuronal activation. However, separating neuronal and astrocytic effects from cocaine's direct vasoactive effects has been challenging, partially due to limitations of neuroimaging techniques able to differentiate vascular from neuronal and glial effects at high temporal and spatial resolutions. Here, we used a newly-developed multi-channel fluorescence and optical coherence Doppler microscope (fl-ODM) that allows for simultaneous measurements of neuronal and astrocytic activities (reflected by the intracellular calcium changes in neurons Ca2+N and astrocytes Ca2+A, respectively) alongside their vascular interactions in vivo to address this challenge. Using green and red genetically-encoded Ca2+ indicators differentially expressed in astrocytes and neurons, fl-ODM enabled concomitant imaging of large-scale astrocytic and neuronal Ca2+ fluorescence and 3D cerebral blood flow velocity (CBFv) in vascular networks in the mouse cortex. We assessed cocaine's effects in the prefrontal cortex (PFC) and found that the CBFv changes triggered by cocaine were temporally correlated with astrocytic Ca2+A activity. Chemogenetic inhibition of astrocytes during the baseline state resulted in blood vessel dilation and CBFv increases but did not affect neuronal activity, suggesting modulation of spontaneous blood vessel's vascular tone by astrocytes. Chemogenetic inhibition of astrocytes during a cocaine challenge prevented its vasoconstricting effects alongside the CBFv decreases, but it also attenuated the neuronal Ca2+N increases triggered by cocaine. These results document a role of astrocytes both in regulating vascular tone and consequently blood flow, at baseline and for modulating the vasoconstricting and neuronal activation responses to cocaine in the PFC. Strategies to inhibit astrocytic activity could offer promise for ameliorating vascular and neuronal toxicity from cocaine misuse.


Assuntos
Astrócitos , Cálcio , Circulação Cerebrovascular , Cocaína , Neurônios , Córtex Pré-Frontal , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Animais , Cocaína/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Masculino , Cálcio/metabolismo , Camundongos Endogâmicos C57BL , Acoplamento Neurovascular/efeitos dos fármacos , Acoplamento Neurovascular/fisiologia
9.
Mol Psychiatry ; 29(9): 2689-2700, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38532010

RESUMO

Depression's link to serotonin dysregulation is well-known. The monoamine theory posits that depression results from impaired serotonin activity, leading to the development of antidepressants targeting serotonin levels. However, their limited efficacy suggests a more complex cause. Recent studies highlight mitochondria as key players in depression's pathophysiology. Mounting evidence indicates that mitochondrial dysfunction significantly correlates with major depressive disorder (MDD), underscoring its pivotal role in depression. Exploring the serotonin-mitochondrial connection, our study investigated the effects of chronic serotonin treatment on induced-pluripotent stem cell-derived astrocytes and neurons from healthy controls and two case study patients. One was a patient with antidepressant non-responding MDD ("Non-R") and another had a non-genetic mitochondrial disorder ("Mito"). The results revealed that serotonin altered the expression of genes related to mitochondrial function and dynamics in neurons and had an equalizing effect on calcium homeostasis in astrocytes, while ATP levels seemed increased. Serotonin significantly decreased cytosolic and mitochondrial calcium in neurons. Electrophysiological measurements evidenced that serotonin depolarized the resting membrane potential, increased both sodium and potassium current density and ultimately improved the overall excitability of neurons. Specifically, neurons from the Non-R patient appeared responsive to serotonin in vitro, which seemed to improve neurotransmission. While it is unclear how this translates to the systemic level and AD resistance mechanisms are not fully elucidated, our observations show that despite his treatment resistance, this patient's cortical neurons are responsive to serotonergic signals. In the Mito patient, evidence suggested that serotonin, by increasing excitability, exacerbated an existing hyperexcitability highlighting the importance of considering mitochondrial disorders in patients with MDD, and avoiding serotonin-increasing medication. Taken together, our findings suggested that serotonin positively affects calcium homeostasis in astrocytes and increases neuronal excitability. The latter effect must be considered carefully, as it could have beneficial or detrimental implications based on individual pathologies.


Assuntos
Astrócitos , Cálcio , Transtorno Depressivo Maior , Células-Tronco Pluripotentes Induzidas , Mitocôndrias , Neurônios , Serotonina , Humanos , Serotonina/metabolismo , Serotonina/farmacologia , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Transtorno Depressivo Maior/metabolismo , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Cálcio/metabolismo , Adulto , Masculino , Feminino , Depressão/metabolismo , Antidepressivos/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia , Pessoa de Meia-Idade
10.
Nature ; 567(7748): 341-346, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30842654

RESUMO

Cancer-specific inhibitors that reflect the unique metabolic needs of cancer cells are rare. Here we describe Gboxin, a small molecule that specifically inhibits the growth of primary mouse and human glioblastoma cells but not that of mouse embryonic fibroblasts or neonatal astrocytes. Gboxin rapidly and irreversibly compromises oxygen consumption in glioblastoma cells. Gboxin relies on its positive charge to associate with mitochondrial oxidative phosphorylation complexes in a manner that is dependent on the proton gradient of the inner mitochondrial membrane, and it inhibits the activity of F0F1 ATP synthase. Gboxin-resistant cells require a functional mitochondrial permeability transition pore that regulates pH and thus impedes the accumulation of Gboxin in the mitochondrial matrix. Administration of a metabolically stable Gboxin analogue inhibits glioblastoma allografts and patient-derived xenografts. Gboxin toxicity extends to established human cancer cell lines of diverse organ origin, and shows that the increased proton gradient and pH in cancer cell mitochondria is a mode of action that can be targeted in the development of antitumour reagents.


Assuntos
Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Aloenxertos , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Linhagem Celular Tumoral , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/enzimologia , Membranas Mitocondriais/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Transplante de Neoplasias , Especificidade de Órgãos , Força Próton-Motriz/efeitos dos fármacos , ATPases Translocadoras de Prótons/antagonistas & inibidores , ATPases Translocadoras de Prótons/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Cereb Cortex ; 34(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38981852

RESUMO

Previously, we found that dCA1 A1-like polarization of astrocytes contributes a lot to the spatial memory deficit in methamphetamine abstinence mice. However, the underlying mechanism remains unclear, resulting in a lack of promising therapeutic targets. Here, we found that methamphetamine abstinence mice exhibited an increased M1-like microglia and A1-like astrocytes, together with elevated levels of interleukin 1α and tumor necrosis factor α in dCA1. In vitro, the M1-like BV2 microglia cell medium, containing high levels of Interleukin 1α and tumor necrosis factor α, elevated A1-like polarization of astrocytes, which weakened their capacity for glutamate clearance. Locally suppressing dCA1 M1-like microglia activation with minocycline administration attenuated A1-like polarization of astrocytes, ameliorated dCA1 neurotoxicity, and, most importantly, rescued spatial memory in methamphetamine abstinence mice. The effective time window of minocycline treatment on spatial memory is the methamphetamine exposure period, rather than the long-term methamphetamine abstinence.


Assuntos
Astrócitos , Transtornos da Memória , Metanfetamina , Microglia , Minociclina , Memória Espacial , Animais , Metanfetamina/toxicidade , Microglia/efeitos dos fármacos , Microglia/metabolismo , Camundongos , Transtornos da Memória/induzido quimicamente , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Memória Espacial/fisiologia , Memória Espacial/efeitos dos fármacos , Masculino , Minociclina/farmacologia , Camundongos Endogâmicos C57BL , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/patologia , Estimulantes do Sistema Nervoso Central/toxicidade
12.
Cell Mol Life Sci ; 81(1): 293, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976012

RESUMO

The function of astrocytes in response to gut microbiota-derived signals has an important role in the pathophysiological processes of central nervous system (CNS) diseases. However, the specific effects of microbiota-derived metabolites on astrocyte activation have not been elucidated yet. Experimental autoimmune encephalomyelitis (EAE) was induced in female C57BL/6 mice as a classical MS model. The alterations of gut microbiota and the levels of short-chain fatty acids (SCFAs) were assessed after EAE induction. We observed that EAE mice exhibit low levels of Allobaculum, Clostridium_IV, Clostridium_XlVb, Lactobacillus genera, and microbial-derived SCFAs metabolites. SCFAs supplementation suppressed astrocyte activation by increasing the level of tryptophan (Trp)-derived AhR ligands that activating the AhR. The beneficial effects of SCFAs supplementation on the clinical scores, histopathological alterations, and the blood brain barrier (BBB)-glymphatic function were abolished by intracisterna magna injection of AAV-GFAP-shAhR. Moreover, SCFAs supplementation suppressed the loss of AQP4 polarity within astrocytes in an AhR-dependent manner. Together, SCFAs potentially suppresses astrocyte activation by amplifying Trp-AhR-AQP4 signaling in EAE mice. Our study demonstrates that SCFAs supplementation may serve as a viable therapy for inflammatory disorders of the CNS.


Assuntos
Aquaporina 4 , Astrócitos , Encefalomielite Autoimune Experimental , Ácidos Graxos Voláteis , Camundongos Endogâmicos C57BL , Receptores de Hidrocarboneto Arílico , Transdução de Sinais , Triptofano , Animais , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/metabolismo , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Ácidos Graxos Voláteis/farmacologia , Ácidos Graxos Voláteis/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Camundongos , Triptofano/metabolismo , Triptofano/farmacologia , Feminino , Transdução de Sinais/efeitos dos fármacos , Aquaporina 4/metabolismo , Aquaporina 4/genética , Microbioma Gastrointestinal/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos
13.
Genes Dev ; 31(8): 757-773, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28465359

RESUMO

Glioblastoma multiforme (GBM) is an aggressive brain tumor driven by cells with hallmarks of neural stem (NS) cells. GBM stem cells frequently express high levels of the transcription factors FOXG1 and SOX2. Here we show that increased expression of these factors restricts astrocyte differentiation and can trigger dedifferentiation to a proliferative NS cell state. Transcriptional targets include cell cycle and epigenetic regulators (e.g., Foxo3, Plk1, Mycn, Dnmt1, Dnmt3b, and Tet3). Foxo3 is a critical repressed downstream effector that is controlled via a conserved FOXG1/SOX2-bound cis-regulatory element. Foxo3 loss, combined with exposure to the DNA methylation inhibitor 5-azacytidine, enforces astrocyte dedifferentiation. DNA methylation profiling in differentiating astrocytes identifies changes at multiple polycomb targets, including the promoter of Foxo3 In patient-derived GBM stem cells, CRISPR/Cas9 deletion of FOXG1 does not impact proliferation in vitro; however, upon transplantation in vivo, FOXG1-null cells display increased astrocyte differentiation and up-regulate FOXO3. In contrast, SOX2 ablation attenuates proliferation, and mutant cells cannot be expanded in vitro. Thus, FOXG1 and SOX2 operate in complementary but distinct roles to fuel unconstrained self-renewal in GBM stem cells via transcriptional control of core cell cycle and epigenetic regulators.


Assuntos
Neoplasias Encefálicas/fisiopatologia , Epigenômica , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica , Glioblastoma/fisiopatologia , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/citologia , Fatores de Transcrição SOXB1/genética , Motivos de Aminoácidos , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Azacitidina/farmacologia , Neoplasias Encefálicas/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Cromatina/metabolismo , Metilação de DNA , Proteína Forkhead Box O3/genética , Proteína Forkhead Box O3/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Glioblastoma/genética , Humanos , Mutação , Proteínas do Tecido Nervoso/metabolismo , Ligação Proteica , Fatores de Transcrição SOXB1/metabolismo , Células Tumorais Cultivadas
14.
J Proteome Res ; 23(8): 3383-3392, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-38943617

RESUMO

Tumor necrosis factor (TNF) has well-established roles in neuroinflammatory disorders, but the effect of TNF on the biochemistry of brain cells remains poorly understood. Here, we microinjected TNF into the brain to study its impact on glial and neuronal metabolism (glycolysis, pentose phosphate pathway, citric acid cycle, pyruvate dehydrogenase, and pyruvate carboxylase pathways) using 13C NMR spectroscopy on brain extracts following intravenous [1,2-13C]-glucose (to probe glia and neuron metabolism), [2-13C]-acetate (probing astrocyte-specific metabolites), or [3-13C]-lactate. An increase in [4,5-13C]-glutamine and [2,3-13C]-lactate coupled with a decrease in [4,5-13C]-glutamate was observed in the [1,2-13C]-glucose-infused animals treated with TNF. As glutamine is produced from glutamate by astrocyte-specific glutamine synthetase the increase in [4,5-13C]-glutamine reflects increased production of glutamine by astrocytes. This was confirmed by infusion with astrocyte substrate [2-13C]-acetate. As lactate is metabolized in the brain to produce glutamate, the simultaneous increase in [2,3-13C]-lactate and decrease in [4,5-13C]-glutamate suggests decreased lactate utilization, which was confirmed using [3-13C]-lactate as a metabolic precursor. These results suggest that TNF rearranges the metabolic network, disrupting the energy supply chain perturbing the glutamine-glutamate shuttle between astrocytes and the neurons. These insights pave the way for developing astrocyte-targeted therapeutic strategies aimed at modulating effects of TNF to restore metabolic homeostasis in neuroinflammatory disorders.


Assuntos
Astrócitos , Encéfalo , Ácido Glutâmico , Glutamina , Neurônios , Fator de Necrose Tumoral alfa , Animais , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Ratos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Ácido Láctico/metabolismo , Glucose/metabolismo , Masculino , Ciclo do Ácido Cítrico/efeitos dos fármacos , Isótopos de Carbono , Glicólise/efeitos dos fármacos , Acetatos/farmacologia , Acetatos/metabolismo , Piruvato Carboxilase/metabolismo , Via de Pentose Fosfato/efeitos dos fármacos
15.
Glia ; 72(10): 1746-1765, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38856177

RESUMO

Cholesterol is crucial for the proper functioning of eukaryotic cells, especially neurons, which rely on cholesterol to maintain their complex structure and facilitate synaptic transmission. However, brain cells are isolated from peripheral cholesterol by the blood-brain barrier and mature neurons primarily uptake the cholesterol synthesized by astrocytes for proper function. This study aimed to investigate the effect of aging on cholesterol trafficking in astrocytes and its delivery to neurons. We found that aged astrocytes accumulated high levels of cholesterol in the lysosomal compartment, and this cholesterol buildup can be attributed to the simultaneous occurrence of two events: decreased levels of the ABCA1 transporter, which impairs ApoE-cholesterol export from astrocytes, and reduced expression of NPC1, which hinders cholesterol release from lysosomes. We show that these two events are accompanied by increased microR-33 in aged astrocytes, which targets ABCA1 and NPC1. In addition, we demonstrate that the microR-33 increase is triggered by oxidative stress, one of the hallmarks of aging. By coculture experiments, we show that cholesterol accumulation in astrocytes impairs the cholesterol delivery from astrocytes to neurons. Remarkably, we found that this altered transport of cholesterol could be alleviated through treatment with endocannabinoids as well as cannabidiol or CBD. Finally, according to data demonstrating that aged astrocytes develop an A1 phenotype, we found that cholesterol buildup is also observed in reactive C3+ astrocytes. Given that reduced neuronal cholesterol affects synaptic plasticity, the ability of cannabinoids to restore cholesterol transport from aged astrocytes to neurons holds significant implications in aging and inflammation.


Assuntos
Transportador 1 de Cassete de Ligação de ATP , Astrócitos , Canabinoides , Colesterol , Lisossomos , Neurônios , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Animais , Colesterol/metabolismo , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/efeitos dos fármacos , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Canabinoides/farmacologia , Canabinoides/metabolismo , Células Cultivadas , Proteína C1 de Niemann-Pick , Camundongos , Envelhecimento/metabolismo , Técnicas de Cocultura , Camundongos Endogâmicos C57BL
16.
Glia ; 72(8): 1501-1517, 2024 08.
Artigo em Inglês | MEDLINE | ID: mdl-38780232

RESUMO

Methamphetamine (Meth) use is known to induce complex neuroinflammatory responses, particularly involving astrocytes and microglia. Building upon our previous research, which demonstrated that Meth stimulates astrocytes to release tumor necrosis factor (TNF) and glutamate, leading to microglial activation, this study investigates the role of the anti-inflammatory cytokine interleukin-10 (IL-10) in this process. Our findings reveal that the presence of recombinant IL-10 (rIL-10) counteracts Meth-induced excessive glutamate release in astrocyte cultures, which significantly reduces microglial activation. This reduction is associated with the modulation of astrocytic intracellular calcium (Ca2+) dynamics, particularly by restricting the release of Ca2+ from the endoplasmic reticulum to the cytoplasm. Furthermore, we identify the small Rho GTPase Cdc42 as a crucial intermediary in the astrocyte-to-microglia communication pathway under Meth exposure. By employing a transgenic mouse model that overexpresses IL-10 (pMT-10), we also demonstrate in vivo that IL-10 prevents Meth-induced neuroinflammation. These findings not only enhance our understanding of Meth-related neuroinflammatory mechanisms, but also suggest IL-10 and Cdc42 as putative therapeutic targets for treating Meth-induced neuroinflammation.


Assuntos
Astrócitos , Interleucina-10 , Metanfetamina , Camundongos Transgênicos , Microglia , Proteína cdc42 de Ligação ao GTP , Animais , Metanfetamina/toxicidade , Metanfetamina/farmacologia , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Proteína cdc42 de Ligação ao GTP/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Estimulantes do Sistema Nervoso Central/toxicidade , Estimulantes do Sistema Nervoso Central/farmacologia , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/induzido quimicamente , Células Cultivadas , Ácido Glutâmico/metabolismo , Ácido Glutâmico/toxicidade
17.
Glia ; 72(9): 1629-1645, 2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38785370

RESUMO

We have previously shown that phosphodiesterase 4 (PDE4) inhibition protects against neuronal injury in rats following middle cerebral artery occlusion/reperfusion (MCAO/R). However, the effects of PDE4 on brain edema and astrocyte swelling are unknown. In this study, we showed that inhibition of PDE4 by Roflumilast (Roflu) reduced brain edema and brain water content in rats subjected to MCAO/R. Roflu decreased the expression of aquaporin 4 (AQP4), while the levels of phosphorylated protein kinase B (Akt) and forkhead box O3a (FoxO3a) were increased. In addition, Roflu reduced cell volume and the expression of AQP4 in primary astrocytes undergoing oxygen and glucose deprivation/reoxygenation (OGD/R). Consistently, PDE4B knockdown showed similar effects as PDE4 inhibition; and PDE4B overexpression rescued the inhibitory role of PDE4B knockdown on AQP4 expression. We then found that the effects of Roflu on the expression of AQP4 and cell volume were blocked by the Akt inhibitor MK2206. Since neuroinflammation and astrocyte activation are the common events that are observed in stroke, we treated primary astrocytes with interleukin-1ß (IL-1ß). Astrocytes treated with IL-1ß showed decreased AQP4 and phosphorylated Akt and FoxO3a. Roflu significantly reduced AQP4 expression, which was accompanied by increased phosphorylation of Akt and FoxO3a. Furthermore, overexpression of FoxO3a partly reversed the effect of Roflu on AQP4 expression. Our findings suggest that PDE4 inhibition limits ischemia-induced brain edema and astrocyte swelling via the Akt/FoxO3a/AQP4 pathway. PDE4 is a promising target for the intervention of brain edema after cerebral ischemia.


Assuntos
Aminopiridinas , Aquaporina 4 , Astrócitos , Benzamidas , Edema Encefálico , Infarto da Artéria Cerebral Média , Inibidores da Fosfodiesterase 4 , Ratos Sprague-Dawley , Traumatismo por Reperfusão , Animais , Aquaporina 4/metabolismo , Aquaporina 4/genética , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Traumatismo por Reperfusão/metabolismo , Inibidores da Fosfodiesterase 4/farmacologia , Masculino , Edema Encefálico/metabolismo , Edema Encefálico/etiologia , Edema Encefálico/patologia , Aminopiridinas/farmacologia , Benzamidas/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Ciclopropanos/farmacologia , Proteína Forkhead Box O3/metabolismo , Ratos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células Cultivadas , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Interleucina-1beta/metabolismo
18.
J Neurochem ; 168(9): 2640-2653, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38761015

RESUMO

Most central nervous diseases are accompanied by astrocyte activation. Autophagy, an important pathway for cells to protect themselves and maintain homeostasis, is widely involved in regulation of astrocyte activation. Reactive astrocytes may play a protective or harmful role in different diseases due to different phenotypes of astrocytes. It is an urgent task to clarify the formation mechanisms of inflammatory astrocyte phenotype, A1 astrocytes. Sestrin2 is a highly conserved protein that can be induced under a variety of stress conditions as a potential protective role in oxidative damage process. However, whether Sestrin2 can affect autophagy and involve in A1 astrocyte conversion is still uncovered. In this study, we reported that Sestrin2 and autophagy were significantly induced in mouse hippocampus after multiple intraperitoneal injections of lipopolysaccharide, with the elevation of A1 astrocyte conversion and inflammatory mediators. Knockdown Sestrin2 in C8-D1A astrocytes promoted the levels of A1 astrocyte marker C3 mRNA and inflammatory factors, which was rescued by autophagy inducer rapamycin. Overexpression of Sestrin2 in C8-D1A astrocytes attenuated A1 astrocyte conversion and reduced inflammatory factor levels via abundant autophagy. Moreover, Sestrin2 overexpression improved mitochondrial structure and morphology. These results suggest that Sestrin2 can suppress neuroinflammation by inhibiting A1 astrocyte conversion via autophagy, which is a potential drug target for treating neuroinflammation.


Assuntos
Astrócitos , Autofagia , Camundongos Endogâmicos C57BL , Doenças Neuroinflamatórias , Animais , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Camundongos , Masculino , Doenças Neuroinflamatórias/metabolismo , Lipopolissacarídeos/farmacologia , Proteínas Nucleares/metabolismo , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/efeitos dos fármacos , Sestrinas
19.
J Neurochem ; 168(9): 3076-3094, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39001671

RESUMO

Gamma-aminobutyric acid (GABA) is the principal inhibitory neurotransmitter in the adult brain that binds to GABA receptors and hyperpolarizes the postsynaptic neuron. Gabazine acts as a competitive antagonist to type A GABA receptors (GABAAR), thereby causing diminished neuronal hyperpolarization and GABAAR-mediated inhibition. However, the biochemical effects and the potential regulatory role of astrocytes in this process remain poorly understood. To address this, we investigated the neuronal responses of gabazine in rat cortical cultures containing varying ratios of neurons and astrocytes. Electrophysiological characterization was performed utilizing microelectrode arrays (MEAs) with topologically controlled microcircuit cultures that enabled control of neuronal network growth. Biochemical analysis of the cultures was performed using traditional dissociated cultures on coverslips. Our study indicates that, upon gabazine stimulation, astrocyte-rich neuronal cultures exhibit elevated electrophysiological activity and tyrosine phosphorylation of tropomyosin receptor kinase B (TrkB; receptor for brain-derived neurotrophic factor), along with distinct cytokine secretion profiles. Notably, neurons lacking proper astrocytic support were found to experience synapse loss and decreased mitogen-activated protein kinase (MAPK) phosphorylation. Furthermore, astrocytes contributed to neuronal viability, morphology, vascular endothelial growth factor (VEGF) secretion, and overall neuronal network functionality, highlighting the multifunctional role of astrocytes.


Assuntos
Astrócitos , Neurônios , Piridazinas , Animais , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Piridazinas/farmacologia , Ratos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Córtex Cerebral/efeitos dos fármacos , Ratos Sprague-Dawley
20.
J Neurochem ; 168(9): 3284-3307, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39135362

RESUMO

The strongest genetic risk factor for late-onset Alzheimer's disease (AD) is allelic variation of the APOE gene, with the following risk structure: ε4 > ε3 > ε2. The biochemical basis for this risk profile is unclear. Here, we reveal a new role for the APOE gene product, apolipoprotein E (ApoE) in regulating cellular copper homeostasis, which is perturbed in the AD brain. Exposure of ApoE target replacement (TR) astrocytes (immortalised astrocytes from APOE knock-in mice) to elevated copper concentrations resulted in exacerbated copper accumulation in ApoE4- compared to ApoE2- and ApoE3-TR astrocytes. This effect was also observed in SH-SY5Y neuroblastoma cells treated with conditioned medium from ApoE4-TR astrocytes. Increased intracellular copper levels in the presence of ApoE4 may be explained by reduced levels and delayed trafficking of the copper transport protein, copper-transporting ATPase 1 (ATP7A/Atp7a), potentially leading to impaired cellular copper export. This new role for ApoE in copper regulation lends further biochemical insight into how APOE genotype confers risk for AD and reveals a potential contribution of ApoE4 to the copper dysregulation that is a characteristic pathological feature of the AD brain.


Assuntos
Apolipoproteína E4 , Astrócitos , Proteínas de Transporte de Cátions , Cobre , Cobre/metabolismo , Apolipoproteína E4/genética , Apolipoproteína E4/metabolismo , Animais , Humanos , Camundongos , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , ATPases Transportadoras de Cobre/metabolismo , ATPases Transportadoras de Cobre/genética , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/genética , Linhagem Celular Tumoral , Camundongos Transgênicos , Células Cultivadas
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