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1.
Proc Natl Acad Sci U S A ; 117(39): 24464-24474, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32929007

RESUMO

Microglia are considered both pathogenic and protective during recovery from demyelination, but their precise role remains ill defined. Here, using an inhibitor of colony stimulating factor 1 receptor (CSF1R), PLX5622, and mice infected with a neurotropic coronavirus (mouse hepatitis virus [MHV], strain JHMV), we show that depletion of microglia during the time of JHMV clearance resulted in impaired myelin repair and prolonged clinical disease without affecting the kinetics of virus clearance. Microglia were required only during the early stages of remyelination. Notably, large deposits of extracellular vesiculated myelin and cellular debris were detected in the spinal cords of PLX5622-treated and not control mice, which correlated with decreased numbers of oligodendrocytes in demyelinating lesions in drug-treated mice. Furthermore, gene expression analyses demonstrated differential expression of genes involved in myelin debris clearance, lipid and cholesterol recycling, and promotion of oligodendrocyte function. The results also demonstrate that microglial functions affected by depletion could not be compensated by infiltrating macrophages. Together, these results demonstrate that microglia play key roles in debris clearance and in the initiation of remyelination following infection with a neurotropic coronavirus but are not necessary during later stages of remyelination.


Assuntos
Infecções por Coronavirus/patologia , Doenças Desmielinizantes/patologia , Microglia/patologia , Remielinização , Animais , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Doenças Desmielinizantes/imunologia , Doenças Desmielinizantes/virologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Imunidade Celular/efeitos dos fármacos , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , Vírus da Hepatite Murina/efeitos dos fármacos , Vírus da Hepatite Murina/fisiologia , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Oligodendroglia/patologia , Compostos Orgânicos/administração & dosagem , Compostos Orgânicos/efeitos adversos , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Remielinização/genética , Medula Espinal/imunologia , Medula Espinal/patologia
2.
Nat Commun ; 11(1): 4071, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792491

RESUMO

Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in multiple sclerosis (MS) is associated with neurodegeneration and clinical worsening. We show that Glutathione S-transferase 4α (Gsta4) is highly expressed during adult OL differentiation and that Gsta4 loss impairs differentiation into myelinating OLs in vitro. In addition, we identify Gsta4 as a target of both dimethyl fumarate, an existing MS therapy, and clemastine fumarate, a candidate remyelinating agent in MS. Overexpression of Gsta4 reduces expression of Fas and activity of the mitochondria-associated Casp8-Bid-axis in adult oligodendrocyte precursor cells, leading to improved OL survival during differentiation. The Gsta4 effect on apoptosis during adult OL differentiation was corroborated in vivo in both lysolecithin-induced demyelination and experimental autoimmune encephalomyelitis models, where Casp8 activity was reduced in Gsta4-overexpressing OLs. Our results identify Gsta4 as an intrinsic regulator of OL differentiation, survival and remyelination, as well as a potential target for future reparative MS therapies.


Assuntos
Glutationa Transferase/metabolismo , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Caspase 8/genética , Caspase 8/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glutationa Transferase/genética , Homeostase/genética , Homeostase/fisiologia , Imuno-Histoquímica , Masculino , Microglia/citologia , Microglia/metabolismo , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Esclerose Múltipla/genética , Esclerose Múltipla/metabolismo , Fagocitose/genética , Fagocitose/fisiologia , Processamento de Proteína Pós-Traducional , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Remielinização/genética , Remielinização/fisiologia
3.
PLoS One ; 15(8): e0237153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32791516

RESUMO

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease characterized by cognitive dysfunction and memory loss as the main symptoms. The deposition of amyloid beta (Aß) and tau hyperphosphorylation are hallmarks of AD and are major therapeutic targets. However, the exact etiology has not yet been fully elucidated; thus, no drug that cures the disease has been approved. JBPOS0101 is a phenyl carbamate compound that has been tested as a drug for epileptic diseases. In our previous study, we showed that JBPOS0101 attenuated the accumulation of Aß as well as the deficits in learning and memory in the 5xFAD mouse model. Here, we tested the dose effect (70 or 35 mg/kg) of JBPOS0101 on the memory defect and pathological markers and further investigated the underlying mechanisms in 5xFAD mice. In the behavior tests, JBPOS0101 treatment ameliorated deficits in learning and memory. Moreover, JBPOS0101 attenuated Aß accumulation and tau phosphorylation. The elevated phosphorylation levels of the active GSK3ß form (GSK3ß-y216) in 5xFAD, which are responsible for tau phosphorylation, decreased in the JBPOS0101-treated groups. Furthermore, the elevation of reactive astrocytes and microglia in 5xFAD mice was attenuated in JBPOS0101-treated groups. These data suggest that JBPOS0101 may be a new drug candidate to lessen amyloid- and tau-related pathology by regulating glial cells.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Microglia/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Proteínas tau/metabolismo , Animais , Feminino , Glicogênio Sintase Quinase 3 beta/metabolismo , Memória , Camundongos , Microglia/metabolismo , Fármacos Neuroprotetores/uso terapêutico
4.
J Virol ; 94(20)2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32796063

RESUMO

Alpha/beta interferon (IFN-α/ß) signaling through the IFN-α/ß receptor (IFNAR) is essential to limit virus dissemination throughout the central nervous system (CNS) following many neurotropic virus infections. However, the distinct expression patterns of factors associated with the IFN-α/ß pathway in different CNS resident cell populations implicate complex cooperative pathways in IFN-α/ß induction and responsiveness. Here we show that mice devoid of IFNAR1 signaling in calcium/calmodulin-dependent protein kinase II alpha (CaMKIIα) expressing neurons (CaMKIIcre:IFNARfl/fl mice) infected with a mildly pathogenic neurotropic coronavirus (mouse hepatitis virus A59 strain [MHV-A59]) developed severe encephalomyelitis with hind-limb paralysis and succumbed within 7 days. Increased virus spread in CaMKIIcre:IFNARfl/fl mice compared to IFNARfl/fl mice affected neurons not only in the forebrain but also in the mid-hind brain and spinal cords but excluded the cerebellum. Infection was also increased in glia. The lack of viral control in CaMKIIcre:IFNARfl/fl relative to control mice coincided with sustained Cxcl1 and Ccl2 mRNAs but a decrease in mRNA levels of IFNα/ß pathway genes as well as Il6, Tnf, and Il1ß between days 4 and 6 postinfection (p.i.). T cell accumulation and IFN-γ production, an essential component of virus control, were not altered. However, IFN-γ responsiveness was impaired in microglia/macrophages irrespective of similar pSTAT1 nuclear translocation as in infected controls. The results reveal how perturbation of IFN-α/ß signaling in neurons can worsen disease course and disrupt complex interactions between the IFN-α/ß and IFN-γ pathways in achieving optimal antiviral responses.IMPORTANCE IFN-α/ß induction limits CNS viral spread by establishing an antiviral state, but also promotes blood brain barrier integrity, adaptive immunity, and activation of microglia/macrophages. However, the extent to which glial or neuronal signaling contributes to these diverse IFN-α/ß functions is poorly understood. Using a neurotropic mouse hepatitis virus encephalomyelitis model, this study demonstrated an essential role of IFN-α/ß receptor 1 (IFNAR1) specifically in neurons to control virus spread, regulate IFN-γ signaling, and prevent acute mortality. The results support the notion that effective neuronal IFNAR1 signaling compensates for their low basal expression of genes in the IFN-α/ß pathway compared to glia. The data further highlight the importance of tightly regulated communication between the IFN-α/ß and IFN-γ signaling pathways to optimize antiviral IFN-γ activity.


Assuntos
Sistema Nervoso Central/virologia , Interferon Tipo I/metabolismo , Interferon gama/metabolismo , Macrófagos/metabolismo , Microglia/metabolismo , Neurônios/metabolismo , Transdução de Sinais , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Sistema Nervoso Central/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Encefalomielite/imunologia , Encefalomielite/virologia , Macrófagos/virologia , Camundongos , Camundongos Mutantes , Microglia/virologia , Vírus da Hepatite Murina/fisiologia , Neurônios/virologia , Infiltração de Neutrófilos , Receptor de Interferon alfa e beta/deficiência , Receptor de Interferon alfa e beta/genética , Receptor de Interferon alfa e beta/metabolismo , Replicação Viral
5.
Nat Commun ; 11(1): 4183, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826893

RESUMO

We describe a human single-nuclei transcriptomic atlas for the substantia nigra (SN), generated by sequencing approximately 17,000 nuclei from matched cortical and SN samples. We show that the common genetic risk for Parkinson's disease (PD) is associated with dopaminergic neuron (DaN)-specific gene expression, including mitochondrial functioning, protein folding and ubiquitination pathways. We identify a distinct cell type association between PD risk and oligodendrocyte-specific gene expression. Unlike Alzheimer's disease (AD), we find no association between PD risk and microglia or astrocytes, suggesting that neuroinflammation plays a less causal role in PD than AD. Beyond PD, we find associations between SN DaNs and GABAergic neuron gene expression and multiple neuropsychiatric disorders. Conditional analysis reveals that distinct neuropsychiatric disorders associate with distinct sets of neuron-specific genes but converge onto shared loci within oligodendrocytes and oligodendrocyte precursors. This atlas guides our aetiological understanding by associating SN cell type expression profiles with specific disease risk.


Assuntos
Expressão Gênica , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Substância Negra/metabolismo , Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Encéfalo , Neurônios Dopaminérgicos/metabolismo , Humanos , Microglia/metabolismo , Mitocôndrias/metabolismo , Doenças do Sistema Nervoso/patologia , Substância Negra/patologia , Transcriptoma
6.
PLoS Negl Trop Dis ; 14(7): e0008413, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32628667

RESUMO

Global Zika virus (ZIKV) outbreaks and their link to microcephaly have raised major public health concerns. However, the mechanism of maternal-fetal transmission remains largely unknown. In this study, we determined the role of yolk sac (YS) microglial progenitors in a mouse model of ZIKV vertical transmission. We found that embryonic (E) days 6.5-E8.5 were a critical window for ZIKV infection that resulted in fetal demise and microcephaly, and YS microglial progenitors were susceptible to ZIKV infection. Ablation of YS microglial progenitors significantly reduced the viral load in both the YS and the embryonic brain. Taken together, these results support the hypothesis that YS microglial progenitors serve as "Trojan horses," contributing to ZIKV fetal brain dissemination and congenital brain defects.


Assuntos
Feto/patologia , Microcefalia/patologia , Microglia/virologia , Complicações Infecciosas na Gravidez/patologia , Infecção por Zika virus/patologia , Zika virus/isolamento & purificação , Animais , Encéfalo/virologia , Modelos Animais de Doenças , Feminino , Feto/virologia , Humanos , Transmissão Vertical de Doença Infecciosa , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microcefalia/embriologia , Microcefalia/virologia , Microglia/metabolismo , Gravidez , Complicações Infecciosas na Gravidez/virologia , Carga Viral , Zika virus/fisiologia , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
7.
Anticancer Res ; 40(8): 4755-4762, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727802

RESUMO

BACKGROUND: Developmental disorders are associated with microglial dysfunction. Oral administration of lipopolysaccharide derived from Pantoea agglomerans bacteria (LPSp) leads to normalization of phagocytic activity of microglia and suppression of inflammation in mice. In this article, we report on a successful trial in which we achieved a significant improvement of symptoms in patients with developmental disorders. PATIENTS AND METHODS: Five pediatric patients diagnosed with autism spectrum disorders (ASD)/attention deficit hyperactivity disorder (ADHD) who visited our clinic received either 0.75 or 1 mg/day LPSp for 6 months or more, in addition to our usual therapy regimens (detoxification therapy, nutritional therapy, and vibration therapy). A survey questionnaire was completed by the patients' parents and evaluated using the Numerical Rating Scale. RESULTS: Behavior, verbal ability, and communication disabilities associated with ASD/ADHD improved in all patients. CONCLUSION: Oral administration of LPSp may represent a new treatment option in the area of developmental disorders where there is currently no treatment available.


Assuntos
Deficiências do Desenvolvimento/tratamento farmacológico , Lipopolissacarídeos/administração & dosagem , Pantoea/química , Administração Oral , Criança , Pré-Escolar , Citocinas/metabolismo , Deficiências do Desenvolvimento/metabolismo , Feminino , Humanos , Masculino , Microglia/efeitos dos fármacos , Microglia/metabolismo , Fagocitose/efeitos dos fármacos
8.
Proc Natl Acad Sci U S A ; 117(32): 19465-19474, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32709745

RESUMO

Infection by malaria parasites triggers dynamic immune responses leading to diverse symptoms and pathologies; however, the molecular mechanisms responsible for these reactions are largely unknown. We performed Trans-species Expression Quantitative Trait Locus analysis to identify a large number of host genes that respond to malaria parasite infections. Here we functionally characterize one of the host genes called receptor transporter protein 4 (RTP4) in responses to malaria parasite and virus infections. RTP4 is induced by type I IFN (IFN-I) and binds to the TANK-binding kinase (TBK1) complex where it negatively regulates TBK1 signaling by interfering with expression and phosphorylation of both TBK1 and IFN regulatory factor 3. Rtp4 -/- mice were generated and infected with malaria parasite Plasmodiun berghei ANKA. Significantly higher levels of IFN-I response in microglia, lower parasitemia, fewer neurologic symptoms, and better survival rates were observed in Rtp4 -/- than in wild-type mice. Similarly, RTP4 deficiency significantly reduced West Nile virus titers in the brain, but not in the heart and the spleen, of infected mice, suggesting a specific role for RTP4 in brain infection and pathology. This study reveals functions of RTP4 in IFN-I response and a potential target for therapy in diseases with neuropathology.


Assuntos
Encéfalo/patologia , Interferon Tipo I/metabolismo , Malária Cerebral/patologia , Chaperonas Moleculares/metabolismo , Animais , Encéfalo/parasitologia , Encéfalo/virologia , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Fator Regulador 3 de Interferon , Malária Cerebral/metabolismo , Malária Cerebral/parasitologia , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Chaperonas Moleculares/genética , Fosforilação , Plasmodium berghei/fisiologia , Plasmodium yoelii/fisiologia , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Febre do Nilo Ocidental/metabolismo , Febre do Nilo Ocidental/patologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/fisiologia
9.
J Thorac Cardiovasc Surg ; 160(2): e55-e66, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32689704

RESUMO

OBJECTIVES: This study aims to evaluate the protective effects of progesterone on white matter injury and brain immaturity in neonatal rats with chronic hypoxia. METHODS: Three-day old Sprague-Dawley rats were randomly divided into 3 groups: (1) control (n = 48), rats were exposed to normoxia (fraction of inspired oxygen: 21% ± 0%); (2) chronic hypoxia (n = 48), rats were exposed to hypoxia (fraction of inspired oxygen: 10.5% ± 1.0%); and (3) progesterone (n = 48), rats were exposed to hypoxia and administrated with progesterone (8 mg/kg/d). Hematoxylin-eosin staining, immunohistochemistry, real-time quantitative polymerase chain reaction, and Western blot analyses were compared on postnatal day 14 in different groups. Motor skill and coordination abilities of rats were assessed via rotation experiments. RESULTS: Increased brain weights (P < .05), narrowed ventricular sizes (P < .01), and rotarod experiment scores (P < .01) were better in the progesterone group than in the chronic hypoxia group. The number of mature oligodendrocytes and myelin basic protein expression increased in the progesterone group compared with the chronic hypoxia group (P < .01). The polarization of M1 microglia cells in the corpus callosum of chronic hypoxia-induced hypomyelination rats was significantly increased, whereas there were fewer M2 microglia cells. Conversely, progesterone therapy had an opposite effect and caused an increase in M2 microglia polarization versus a reduction in M1 microglia cells. CONCLUSIONS: Progesterone could prevent white matter injury and improve brain maturation in a neonatal hypoxic rat model; this may be associated with inducing a switch from M1 to M2 in microglia.


Assuntos
Encéfalo/efeitos dos fármacos , Hipóxia/tratamento farmacológico , Leucoencefalopatias/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Progesterona/farmacologia , Substância Branca/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Plasticidade Celular/efeitos dos fármacos , Doença Crônica , Modelos Animais de Doenças , Feminino , Hipóxia/metabolismo , Hipóxia/patologia , Hipóxia/fisiopatologia , Leucoencefalopatias/metabolismo , Leucoencefalopatias/patologia , Leucoencefalopatias/fisiopatologia , Masculino , Microglia/efeitos dos fármacos , Microglia/metabolismo , Microglia/patologia , Atividade Motora/efeitos dos fármacos , Proteína Básica da Mielina/metabolismo , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/metabolismo , Oligodendroglia/patologia , Ratos Sprague-Dawley , Substância Branca/metabolismo , Substância Branca/patologia , Substância Branca/fisiopatologia
10.
Nat Commun ; 11(1): 3440, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651387

RESUMO

In recent years, exploration of the brain extracellular space (ECS) has made remarkable progress, including nanoscopic characterizations. However, whether ECS precise conformation is altered during brain pathology remains unknown. Here we study the nanoscale organization of pathological ECS in adult mice under degenerative conditions. Using electron microscopy in cryofixed tissue and single nanotube tracking in live brain slices combined with super-resolution imaging analysis, we find enlarged ECS dimensions and increased nanoscale diffusion after α-synuclein-induced neurodegeneration. These animals display a degraded hyaluronan matrix in areas close to reactive microglia. Furthermore, experimental hyaluronan depletion in vivo reduces dopaminergic cell loss and α-synuclein load, induces microgliosis and increases ECS diffusivity, highlighting hyaluronan as diffusional barrier and local tissue organizer. These findings demonstrate the interplay of ECS, extracellular matrix and glia in pathology, unraveling ECS features relevant for the α-synuclein propagation hypothesis and suggesting matrix manipulation as a disease-modifying strategy.


Assuntos
Encéfalo/metabolismo , Espaço Extracelular/metabolismo , Ácido Hialurônico/metabolismo , Sinucleinopatias/metabolismo , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Microglia/ultraestrutura , Microscopia Eletrônica , Doença de Parkinson/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho
11.
Nat Commun ; 11(1): 3687, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703941

RESUMO

Microglia, resident immune cells of the CNS, are thought to defend against infections. Toxoplasma gondii is an opportunistic infection that can cause severe neurological disease. Here we report that during T. gondii infection a strong NF-κB and inflammatory cytokine transcriptional signature is overrepresented in blood-derived macrophages versus microglia. Interestingly, IL-1α is enriched in microglia and IL-1ß in macrophages. We find that mice lacking IL-1R1 or IL-1α, but not IL-1ß, have impaired parasite control and immune cell infiltration within the brain. Further, we show that microglia, not peripheral myeloid cells, release IL-1α ex vivo. Finally, we show that ex vivo IL-1α release is gasdermin-D dependent, and that gasdermin-D and caspase-1/11 deficient mice show deficits in brain inflammation and parasite control. These results demonstrate that microglia and macrophages are differently equipped to propagate inflammation, and that in chronic T. gondii infection, microglia can release the alarmin IL-1α, promoting neuroinflammation and parasite control.


Assuntos
Interleucina-1alfa/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Microglia/imunologia , Proteínas de Ligação a Fosfato/metabolismo , Toxoplasma/imunologia , Toxoplasmose Cerebral/imunologia , Animais , Encéfalo/citologia , Encéfalo/imunologia , Encéfalo/parasitologia , Encéfalo/patologia , Células Cultivadas , Doença Crônica , Modelos Animais de Doenças , Humanos , Interleucina-1alfa/genética , Interleucina-1alfa/imunologia , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Microglia/metabolismo , Proteínas de Ligação a Fosfato/genética , Proteínas de Ligação a Fosfato/imunologia , Toxoplasma/isolamento & purificação , Toxoplasmose Cerebral/sangue , Toxoplasmose Cerebral/parasitologia , Toxoplasmose Cerebral/patologia
12.
Nat Commun ; 11(1): 2709, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32483169

RESUMO

Aberrant immune responses including reactive phagocytes are implicated in the etiology of age-related macular degeneration (AMD), a major cause of blindness in the elderly. The translocator protein (18 kDa) (TSPO) is described as a biomarker for reactive gliosis, but its biological functions in retinal diseases remain elusive. Here, we report that tamoxifen-induced conditional deletion of TSPO in resident microglia using Cx3cr1CreERT2:TSPOfl/fl mice or targeting the protein with the synthetic ligand XBD173 prevents reactivity of phagocytes in the laser-induced mouse model of neovascular AMD. Concomitantly, the subsequent neoangiogenesis and vascular leakage are prevented by TSPO knockout or XBD173 treatment. Using different NADPH oxidase-deficient mice, we show that TSPO is a key regulator of NOX1-dependent neurotoxic ROS production in the retina. These data define a distinct role for TSPO in retinal phagocyte reactivity and highlight the protein as a drug target for immunomodulatory and antioxidant therapies for AMD.


Assuntos
NADPH Oxidase 1/genética , Neovascularização Patológica/genética , Fagócitos/metabolismo , Receptores de GABA/genética , Degeneração Macular Exsudativa/genética , Animais , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/metabolismo , NADPH Oxidase 1/metabolismo , Neovascularização Patológica/metabolismo , Fagócitos/efeitos dos fármacos , Purinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Receptores de GABA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Degeneração Macular Exsudativa/metabolismo
13.
PLoS Pathog ; 16(6): e1008653, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32598380

RESUMO

The clinical course of prion diseases is accurately predictable despite long latency periods, suggesting that prion pathogenesis is driven by precisely timed molecular events. We constructed a searchable genome-wide atlas of mRNA abundance and splicing alterations during the course of disease in prion-inoculated mice. Prion infection induced PrP-dependent transient changes in mRNA abundance and processing already at eight weeks post inoculation, well ahead of any neuropathological and clinical signs. In contrast, microglia-enriched genes displayed an increase simultaneous with the appearance of clinical signs, whereas neuronal-enriched transcripts remained unchanged until the very terminal stage of disease. This suggests that glial pathophysiology, rather than neuronal demise, could be the final driver of disease. The administration of young plasma attenuated the occurrence of early mRNA abundance alterations and delayed signs in the terminal phase of the disease. The early onset of prion-induced molecular changes might thus point to novel biomarkers and potential interventional targets.


Assuntos
Estudo de Associação Genômica Ampla , Microglia/metabolismo , Neurônios/metabolismo , Doenças Priônicas , RNA Mensageiro , Transcriptoma , Animais , Masculino , Camundongos , Camundongos Knockout , Doenças Priônicas/genética , Doenças Priônicas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
14.
Am J Physiol Regul Integr Comp Physiol ; 319(2): R233-R242, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579854

RESUMO

Continuous infusion of prostaglandin E1 (PGE1) is used to maintain ductus arteriosus patency in infants with critical congenital heart disease, but it can also cause central apnea suggesting an effect on respiratory neural control. In this study, we investigated whether 1) PGE1 inhibits the various phases of the acute hypoxic ventilatory response (HVR; an index of respiratory control dysfunction) and increases apnea incidence in neonatal rats; and 2) whether these changes would be reversible with caffeine pretreatment. Whole body plethysmography was used to assess the HVR and apnea incidence in neonatal rats 2 h following a single bolus intraperitoneal injection of PGE1 with and without prior caffeine treatment. Untreated rats exhibited a biphasic HVR characterized by an initial increase in minute ventilation followed by a ventilatory decline of the late phase (~5th minute) of the HVR. PGE1 had a dose-dependent effect on the HVR. Contrary to our hypothesis, the lowest dose (1 µg/kg) of PGE1 prevented the ventilatory decline of the late phase of the HVR. However, PGE1 tended to increase postsigh apnea incidence and the coefficient of variability (CV) of breathing frequency, suggesting increased respiratory instability. PGE1 also decreased brainstem microglia mRNA and increased neuronal nitric oxide synthase (nNOS) and platelet-derived growth factor-ß (PDGF-ß) gene expression. Caffeine pretreatment prevented these effects of PGE1, and the adenosine A2A receptor inhibitor MSX-3 had similar preventative effects. Prostaglandin appears to have deleterious effects on brainstem respiratory control regions, possibly involving a microglial-dependent mechanism. The compensatory effects of caffeine or MSX-3 treatment raises the question of whether prostaglandin may also operate on an adenosine-dependent pathway.


Assuntos
Alprostadil/farmacologia , Tronco Encefálico/efeitos dos fármacos , Cafeína/farmacologia , Ventilação Pulmonar/efeitos dos fármacos , Respiração/efeitos dos fármacos , Animais , Tronco Encefálico/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Pletismografia Total , Proteínas Proto-Oncogênicas c-sis/genética , Proteínas Proto-Oncogênicas c-sis/metabolismo , Antagonistas de Receptores Purinérgicos P1/farmacologia , Ratos , Ratos Sprague-Dawley
15.
Neuron ; 107(3): 417-435, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32579881

RESUMO

Identifying effective treatments for Alzheimer's disease (AD) has proven challenging and has instigated a shift in AD research focus toward the earliest disease-initiating cellular mechanisms. A key insight has been an increase in soluble Aß oligomers in early AD that is causally linked to neuronal and circuit hyperexcitability. However, other accumulating AD-related peptides and proteins, including those derived from the same amyloid precursor protein, such as Aη or sAPPα, and autonomously, such as tau, exhibit surprising opposing effects on circuit dynamics. We propose that the effects of these on neuronal circuits have profound implications for our understanding of disease complexity and heterogeneity and for the development of personalized diagnostic and therapeutic strategies in AD. Here, we highlight important peptide-specific mechanisms of dynamic pathological disequilibrium of cellular and circuit activity in AD and discuss approaches in which these may be further understood, and theoretically and experimentally leveraged, to elucidate AD pathophysiology.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/metabolismo , Neurônios/metabolismo , Convulsões/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/fisiopatologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Astrócitos/metabolismo , Segmento Inicial do Axônio/metabolismo , Encéfalo/fisiopatologia , Humanos , Microglia/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.1/metabolismo , Vias Neurais , Fragmentos de Peptídeos/metabolismo , Receptores de Glutamato/metabolismo , Convulsões/fisiopatologia , Sinapses/metabolismo
16.
Nat Immunol ; 21(7): 802-815, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32541832

RESUMO

Microglia and central nervous system (CNS)-associated macrophages (CAMs), such as perivascular and meningeal macrophages, are implicated in virtually all diseases of the CNS. However, little is known about their cell-type-specific roles in the absence of suitable tools that would allow for functional discrimination between the ontogenetically closely related microglia and CAMs. To develop a new microglia gene targeting model, we first applied massively parallel single-cell analyses to compare microglia and CAM signatures during homeostasis and disease and identified hexosaminidase subunit beta (Hexb) as a stably expressed microglia core gene, whereas other microglia core genes were substantially downregulated during pathologies. Next, we generated HexbtdTomato mice to stably monitor microglia behavior in vivo. Finally, the Hexb locus was employed for tamoxifen-inducible Cre-mediated gene manipulation in microglia and for fate mapping of microglia but not CAMs. In sum, we provide valuable new genetic tools to specifically study microglia functions in the CNS.


Assuntos
Encéfalo/patologia , Encefalomielite Autoimune Experimental/patologia , Traumatismos do Nervo Facial/patologia , Microglia/metabolismo , Cadeia beta da beta-Hexosaminidase/metabolismo , Animais , Encéfalo/citologia , Encéfalo/imunologia , Sistemas CRISPR-Cas/genética , Encefalomielite Autoimune Experimental/imunologia , Traumatismos do Nervo Facial/imunologia , Técnicas de Introdução de Genes , Genes Reporter/genética , Loci Gênicos/genética , Humanos , Microscopia Intravital , Substâncias Luminescentes/química , Proteínas Luminescentes/química , Proteínas Luminescentes/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Microglia/imunologia , Células NIH 3T3 , RNA-Seq , Análise de Célula Única , Transfecção , Cadeia beta da beta-Hexosaminidase/genética
17.
Toxicol Appl Pharmacol ; 401: 115090, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32512069

RESUMO

Copper dyshomeostasis is involved in the pathogenesis of Alzheimer's disease (AD). Microglia play a major role in the proteolytic clearance of oligomeric ß-amyloid (Aßo). Here, we investigated whether Cu(II) affects microglial Aßo clearance and whether this effect involves autophagy-lysosomal pathway. Microtubule associated protein 1 light chain 3 (LC3)-II and p62 protein levels and autophagic flux in Cu(II)-treated microglia were detected. Aßo clearance was detected by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence. In vivo, Cu(II) and Aßo were injected into mouse hippocampus to evaluate Aß clearance. The results showed that Cu(II) inhibited phagocytic uptake and intracellular degradation of Aßo in microglial cultures. Additionally, Cu(II) elevated LC3-II and p62 protein levels and impaired autophagic flux. It also inhibited transcription factor EB (TFEB) expression and lysosomal biogenesis. Moreover, Cu(II) activated mammalian target of rapamycin kinase (mTOR), an upstream signaling of TFEB. The mTOR inhibitor PP242 ameliorated Cu(II)-impaired TFEB expression, lysosomal biogenesis, autophagic flux, and Aßo clearance in microglia. In vivo, Cu(II) inhibited microglial Aßo clearance in mouse hippocampus, an effect accompanied with activation of mTOR and impairment of TFEB expression and lysosomal biogenesis. Collectively, our results suggest that Cu(II) reduces microglial Aßo clearance through disrupting lysosomal biogenesis and autophagic flux. This effect could involve modulation of mTOR-TFEB axis and was prevented by pharmacological antagonism of mTOR. This study reveals a novel mechanism for Cu(II) involvement in AD. Our results implicate that rescue of Cu(II)-impaired autophagy-mediated lysosomal degradation may provide a new strategy to benefit multiple neurodegenerative disorders.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Cobre/toxicidade , Lisossomos/metabolismo , Microglia/metabolismo , Fragmentos de Peptídeos/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Peptídeos beta-Amiloides/antagonistas & inibidores , Animais , Animais Recém-Nascidos , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/antagonistas & inibidores , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Lisossomos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Fragmentos de Peptídeos/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/antagonistas & inibidores
18.
Proc Natl Acad Sci U S A ; 117(26): 14694-14702, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32554491

RESUMO

Innate immune cells destroy pathogens within a transient organelle called the phagosome. When pathogen-associated molecular patterns (PAMPs) displayed on the pathogen are recognized by Toll-like receptors (TLRs) on the host cell, it activates inducible nitric oxide synthase (NOS2) which instantly fills the phagosome with nitric oxide (NO) to clear the pathogen. Selected pathogens avoid activating NOS2 by concealing key PAMPs from their cognate TLRs. Thus, the ability to map NOS2 activity triggered by PAMPs can reveal critical mechanisms underlying pathogen susceptibility. Here, we describe DNA-based probes that ratiometrically report phagosomal and endosomal NO, and can be molecularly programmed to display precise stoichiometries of any desired PAMP. By mapping phagosomal NO produced in microglia of live zebrafish brains, we found that single-stranded RNA of bacterial origin acts as a PAMP and activates NOS2 by engaging TLR-7. This technology can be applied to study PAMP-TLR interactions in diverse organisms.


Assuntos
Encéfalo/enzimologia , DNA/química , Corantes Fluorescentes/química , Óxido Nítrico Sintase Tipo II , Animais , Encéfalo/metabolismo , Química Encefálica , DNA/metabolismo , Corantes Fluorescentes/metabolismo , Técnicas de Inativação de Genes , Camundongos , Microglia/química , Microglia/enzimologia , Microglia/metabolismo , Microscopia de Fluorescência , Sondas Moleculares/química , Sondas Moleculares/metabolismo , Óxido Nítrico Sintase Tipo II/análise , Óxido Nítrico Sintase Tipo II/química , Óxido Nítrico Sintase Tipo II/metabolismo , Fagossomos/química , Fagossomos/metabolismo , Peixe-Zebra
19.
Life Sci ; 256: 117992, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32569781

RESUMO

AIMS: C1q/tumor necrosis factor-related protein-1 (CTRP1) is a newly identified adiponectin paralog that modulates metabolism and inflammation. However, the cerebral function of CTRP1 remains unknown. This study aimed to determine its role and mechanism in cerebral ischemia and reperfusion injury. MAIN METHODS: Serum level of CTRP1 as well as high-sensitivity C reactive protein (hs-CRP) in stroke patients was measured by ELISA assay. The levels of TNF-α, IL-1ß, and IL-6 were analyzed using ELISA kits. Quantitative RT-PCR, western blot analysis were conducted to detect indicated genes. KEY FINDINGS: CTRP1 was significantly upregulated in sera from patients with stroke and positive correlation with hs-CRP. CTRP1 was significantly upregulated in BV2 microglia exposed to oxygen and glucose deprivation and reperfusion (OGD/R). Knockdown of CTRP1 by si-CTRP1 transfection markedly enhanced OGD/R-induced autophagy and accelerated the inflammatory response in BV2 cells, as indicated by increased expression of LC3-II/LC3-I and beclin1, as well as increased concentration of the proinflammatory cytokines TNF-α, IL-1ß, and IL-6. However, recombinant CTRP1 or overexpression of CTRP1 attenuated OGD/R-induced autophagy and inflammatory response in BV2 cells. Further study demonstrated that knockdown of CTRP1 decreased, while recombinant CTRP1 increased the phosphorylation of Akt and mTOR in BV2 cells. IGF-1, which activates PI3-kinase and MEK1/2, abolished the promotive effect of si-CTRP1, while inhibition of Akt with A6730 reversed the inhibitory effect of recombinant CTRP1 on BV2 cells autophagy and inflammation response. SIGNIFICANCE: CTRP1 inhibited microglia autophagy and inflammation response by regulating the Akt/mTOR pathway.


Assuntos
Autofagia/fisiologia , Microglia/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Adulto , Animais , Linhagem Celular , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Acidente Vascular Cerebral/metabolismo
20.
Chem Biol Interact ; 325: 109126, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32430275

RESUMO

Alzheimer's disease (AD) is a common neurodegenerative disease, and its pathogenesis is closely related to ß-amyloid (Aß) peptide. The deposition of Aß in the brain due to impaired Aß clearance is considered as an important cause of AD. The decrease in Aß clearance is closely related to the autophagy dysfunction in brains of AD patients. It is feasible to treat AD by increasing the autophagy level of cells such as microglia and neurons to accelerate Aß clearance. In this article we explored the ability of graphene oxide (GO) to clear Aß through activating autophagy. Our work demonstrated that GO could inhibit the mTOR signaling pathway by activating AMPK to induce the autophagy of microglial and neurons. As expected, with the improvement of autophagy ability of microglia, GO promoted microglia-mediated Aß phagocytosis. Under the conditions of co-culture of microglia and neurons, GO induced the autophagy of microglia and neurons, especially the autophagy of microglia, thereby promoting the clearance of Aß, and ultimately achieved the effect of protecting neurons. Moreover, GO was not only non-cytotoxic to microglia and neurons but also able to reduce the toxicity of Aß to neurons through its clearance. These results have shown the potential of GO in treating Alzheimer's disease.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Autofagia/efeitos dos fármacos , Grafite/farmacologia , Microglia/citologia , Microglia/efeitos dos fármacos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Humanos , Camundongos , Microglia/metabolismo , Neurônios/metabolismo , Fagocitose/efeitos dos fármacos
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