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1.
Acta Cir Bras ; 35(4): e202000406, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578724

RESUMO

PURPOSE: To investigate the role of Rosmarinic acid (RA) in the prevention of traumatic brain injury and the immunohistochemical analysis of IBA-1 and GFAP expressions. METHODS: Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows; control group, traumatic brain injury (TBI) group, and TBI+RA group. After traumatic brain injury, blood samples were taken from the animals and analyzed with various biochemical markers. And then IBA-1 and GFAP expressions were evaluated immunohistochemically. RESULTS: Significant results were obtained in all biochemical parameters between groups. Immunohistochemical sections showed IBA-1 not only in microglia and macrophage activity but also in degenerative neurons in blood vessel endothelial cells. However, GFAP reaction and post-traumatic rosmarinic acid administration showed positive expression in astrocytes with regular structure around the blood vessel. CONCLUSION: Rosmarinic acid in blood vessel endothelial cells showed that preserving the integrity of astrocytic structure in the blood brain barrier may be an important antioxidant.


Assuntos
Lesões Encefálicas Traumáticas/prevenção & controle , Proteínas de Ligação ao Cálcio/análise , Cinamatos/farmacologia , Craniotomia/métodos , Depsídeos/farmacologia , Proteína Glial Fibrilar Ácida/análise , Proteínas dos Microfilamentos/análise , Fármacos Neuroprotetores/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/cirurgia , Glutationa Peroxidase/análise , Imuno-Histoquímica , Masculino , Malondialdeído/análise , Distribuição Aleatória , Ratos Sprague-Dawley , Valores de Referência , Reprodutibilidade dos Testes
2.
Int J Nanomedicine ; 15: 3639-3647, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547019

RESUMO

Purpose: Astrocyte dysfunction is a hallmark of central nervous system injury or infection. As a primary contributor to neurodegeneration, astrocytes are an ideal therapeutic target to combat neurodegenerative conditions. Gene therapy has arisen as an innovative technique that provides excellent prospect for disease intervention. Poly (lactide-co-glycolide) (PLGA) and polyethylenimine (PEI) are polymeric nanoparticles commonly used in gene delivery, each manifesting their own set of advantages and disadvantages. As a clinically approved polymer by the Federal Drug Administration, well characterized for its biodegradability and biocompatibility, PLGA-based nanoparticles (PLGA-NPs) are appealing for translational gene delivery systems. However, our investigations revealed PLGA-NPs were ineffective at facilitating exogenous gene expression in primary human astrocytes, despite their success in other cell lines. Furthermore, PEI polymers illustrate high delivery efficiency but induce cytotoxicity. The purpose of this study is to develop viable and biocompatible NPsystem for astrocyte-targeted gene therapy. Materials and Methods: Successful gene expression by PLGA-NPs alone or in combination with arginine-modified PEI polymers (AnPn) was assessed by a luciferase reporter gene encapsulated in PLGA-NPs. Cytoplasmic release and nuclear localization of DNA were investigated using fluorescent confocal imaging with YOYO-labeled plasmid DNA (pDNA). NP-mediated cytotoxicity was assessed via lactate dehydrogenase in primary human astrocytes and neurons. Results: Confocal imaging of YOYO-labeled pDNA confirmed PLGA-NPs delivered pDNA to the cytoplasm in a dose and time-dependent manner. However, co-staining revealed pDNA delivered by PLGA-NPs did not localize to the nucleus. The addition of AnPn significantly improved nuclear localization of pDNA and successfully achieved gene expression in primary human astrocytes. Moreover, these formulations were biocompatible with both astrocytes and neurons. Conclusion: By co-transfecting two polymeric NPs, we developed an improved system for gene delivery and expression in primary human astrocytes. These findings provide a basis for a biocompatible and clinically translatable method to regulate astrocyte function during neurodegenerative diseases and disorders.


Assuntos
Arginina/química , Astrócitos/metabolismo , Técnicas de Transferência de Genes , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , DNA/genética , Células HEK293 , Humanos , Tamanho da Partícula , Plasmídeos/genética , Polietilenoimina , Transfecção
3.
Int J Nanomedicine ; 15: 3649-3667, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32547020

RESUMO

Introduction: The polyphenolic spice and food coloring ingredient curcumin has beneficial effects in a broad variety of inflammatory diseases. Amongst them, curcumin has been shown to attenuate microglia reaction and prevent from glial scar formation in spinal cord and brain injuries. Methods: We developed a protocol for the efficient encapsulation of curcumin as a model for anti-inflammatory drugs yielding long-term stable, non-toxic liposomes with favorable physicochemical properties. Subsequently, we evaluate the effects of liposomal curcumin in experimental models for neuroinflammation and reactive astrogliosis. Results: We could show that liposomal curcumin can efficiently reduce the reactivity of human microglia and astrocytes and preserve tissue integrity of murine organotypic cortex slices. Discussion and Perspective: In perspective, we want to administer this curcumin formulation in brain implant coatings to prevent neuroinflammation and glial scar formation as foreign body responses of the brain towards implanted materials.


Assuntos
Encéfalo/patologia , Curcumina/uso terapêutico , Gliose/tratamento farmacológico , Inflamação/tratamento farmacológico , Neuroglia/patologia , Animais , Anti-Inflamatórios/farmacologia , Astrócitos/efeitos dos fármacos , Astrócitos/ultraestrutura , Encéfalo/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Curcumina/farmacologia , Humanos , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Lipossomos , Camundongos , Microglia/efeitos dos fármacos , Microglia/ultraestrutura , Neuroglia/efeitos dos fármacos
4.
Toxicol Lett ; 331: 188-199, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32569805

RESUMO

Methamphetamine (METH) is a highly addictive psychostimulant drug whose abuse can cause many health complications. Our previous studies have shown that METH exposure increases α-synuclein (α-syn) expression. Recently, it was shown that α-syn could be transferred from neurons to astrocytes via exosomes. However, the specific role of astrocytes in α-syn pathology involved in METH neurotoxicity remains unclear. The objective of this study was to determine whether exosomes derived from METH-treated neurons contain pathological α-syn and test the hypothesis that exosomes can transfer pathological α-syn from neurons to astrocytes. To this end, using animal and cell line coculture models, we show that exosomes isolated from METH-treated SH-SY5Y cells contained pathological α-syn. Furthermore, the addition of METH exosomes to the medium of primary cultured astrocytes induced α-syn aggregation and inflammatory responses in astrocytes. Then, we evaluated changes in nuclear receptor related 1 protein (Nurr1) expression and the levels of inflammatory cytokines in primary cultured astrocytes exposed to METH or α-syn. We found that METH or α-syn exposure decreased Nurr1 expression and increased proinflammatory cytokine expression in astrocytes. Our results indicate that α-syn can be transferred from neuronal cells to astrocytes through exosomes. When internalized α-syn accumulated in astrocytes, the cells produced inflammatory responses. Nurr1 may play a crucial role in this process and could be a therapeutic target for inflammatory damage caused by METH.


Assuntos
Astrócitos/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/toxicidade , Exossomos/metabolismo , Metanfetamina/toxicidade , Neurônios/efeitos dos fármacos , Síndromes Neurotóxicas/metabolismo , alfa-Sinucleína/metabolismo , Animais , Astrócitos/imunologia , Astrócitos/metabolismo , Linhagem Celular Tumoral , Técnicas de Cocultura , Citocinas/metabolismo , Hipocampo/citologia , Humanos , Injeções Intraperitoneais , Masculino , Camundongos Endogâmicos C57BL , Neurônios/imunologia , Neurônios/metabolismo , Síndromes Neurotóxicas/imunologia , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Cultura Primária de Células , Sinucleinopatias/imunologia , Sinucleinopatias/metabolismo
5.
Aging (Albany NY) ; 12(11): 10035-10040, 2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32534451

RESUMO

Cell senescence is a process that causes growth arrest and the release of a senescence associated secretory phenotype (SASP), characterized by secretion of chemokines, cytokines, cell growth factors and metalloproteases, leading to a tissue condition that may precipitate cancers and neurodegenerative processes. With the recent pandemic of coronavirus, senolytic drugs are being considered as possible therapeutic tools to reduce the virulence of SARS-CoV-2. In the last few years, our research group showed that lithium carbonate at microdose levels was able to stabilize memory and change neuropathological characteristics of Alzheimer's disease (AD). In the present work, we present evidence that low-dose lithium can reduce the SASP of human iPSCs-derived astrocytes following acute treatment, suggesting that microdose lithium could protect cells from senescence and development of aging-related conditions. With the present findings, a perspective of the potential use of low-dose lithium in old patients from the "high risk group" for COVID-19 (with hypertension, diabetes and chronic obstructive pulmonary disease) is presented.


Assuntos
Astrócitos/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Compostos de Lítio/uso terapêutico , Pneumonia Viral/tratamento farmacológico , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Humanos , Pandemias
6.
PLoS One ; 15(5): e0232779, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32365083

RESUMO

Apoptosis of neurovascular cells, including astroglial cells, contributes to the pathogenesis of diseases in which neurovascular disruption plays a central role. Bim is a pro-apoptotic protein that modulates not only apoptosis but also various cellular functions such as migration and extracellular matrix protein expression. Astroglial cells act as an intermediary between neural and vascular cells facilitating retinal vascular development and remodeling while maintaining normal vascular function and neuronal integrity. We previously showed that Bim deficient (Bim -/-) mice were protected from hyperoxia mediated vessel obliteration and ischemia-mediated retinal neovascularization. However, the underlying mechanisms and more specifically the role Bim expression in astroglial cells play remains elusive. Here, using retinal astroglial cells prepared from wild-type and Bim -/- mice, we determined the impact of Bim expression in retinal astroglial cell function. We showed that astroglial cells lacking Bim expression demonstrate increased VEGF expression and altered matricellular protein production including increased expression of thrombospondin-2 (TSP2), osteopontin and SPARC. Bim deficient astroglial cells also exhibited altered proliferation, migration, adhesion to various extracellular matrix proteins and increased expression of inflammatory mediators. Thus, our data emphasizes the importance of Bim expression in retinal astroglia cell autonomous regulatory mechanisms, which could influence neurovascular function.


Assuntos
Astrócitos/metabolismo , Proteína 11 Semelhante a Bcl-2/genética , Inflamação/genética , Retina/metabolismo , Animais , Apoptose/genética , Astrócitos/patologia , Movimento Celular/genética , Proliferação de Células/genética , Proteínas da Matriz Extracelular/genética , Regulação da Expressão Gênica/genética , Humanos , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Neovascularização Fisiológica/genética , Neurônios/metabolismo , Osteonectina/genética , Osteopontina/genética , Retina/patologia , Trombospondinas/genética , Fator A de Crescimento do Endotélio Vascular/genética
7.
PLoS One ; 15(5): e0229702, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413082

RESUMO

The Glymphatic System (GS) has been proposed as a mechanism to clear brain tissue from waste. Its dysfunction might lead to several brain pathologies, including the Alzheimer's disease. A key component of the GS and brain tissue water circulation is the astrocyte which is regulated by acquaporin-4 (AQP4), a membrane-bound water channel on the astrocytic end-feet. Here we investigated the potential of diffusion MRI to monitor astrocyte activity in a mouse brain model through the inhibition of AQP4 channels with TGN-020. Upon TGN-020 injection, we observed a significant decrease in the Sindex, a diffusion marker of tissue microstructure, and a significant increase of the water diffusion coefficient (sADC) in cerebral cortex and hippocampus compared to saline injection. These results indicate the suitability of diffusion MRI to monitor astrocytic activity in vivo and non-invasively.


Assuntos
Aquaporina 4/metabolismo , Astrócitos/metabolismo , Encéfalo/efeitos dos fármacos , Niacinamida/análogos & derivados , Tiadiazóis/farmacologia , Animais , Aquaporina 4/antagonistas & inibidores , Astrócitos/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Imagem de Difusão por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/farmacologia
8.
PLoS Biol ; 18(5): e3000660, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453744

RESUMO

Increased life expectancy of patients diagnosed with HIV in the current era of antiretroviral therapy is unfortunately accompanied with the prevalence of HIV-associated neurocognitive disorders (HANDs) and risk of comorbidities such as Alzheimer-like pathology. HIV-1 transactivator of transcription (Tat) protein has been shown to induce the production of toxic neuronal amyloid protein and also enhance neurotoxicity. The contribution of astrocytes in Tat-mediated amyloidosis remains an enigma. We report here, in simian immunodeficiency virus (SIV)+ rhesus macaques and patients diagnosed with HIV, brain region-specific up-regulation of amyloid precursor protein (APP) and Aß (40 and 42) in astrocytes. In addition, we find increased expression of ß-site cleaving enzyme (BACE1), APP, and Aß in human primary astrocytes (HPAs) exposed to Tat. Mechanisms involved up-regulation of hypoxia-inducible factor (HIF-1α), its translocation and binding to the long noncoding RNA (lncRNA) BACE1-antisense transcript (BACE1-AS), resulting, in turn, in the formation of the BACE1-AS/BACE1 RNA complex, subsequently leading to increased BACE1 protein, and activity and generation of Aß-42. Gene silencing approaches confirmed the regulatory role of HIF-1α in BACE1-AS/BACE1 in Tat-mediated amyloidosis. This is the first report implicating the role of the HIF-1α/lncRNABACE1-AS/BACE1 axis in Tat-mediated induction of astrocytic amyloidosis, which could be targeted as adjunctive therapies for HAND-associated Alzheimer-like comorbidity.


Assuntos
Amiloidose/virologia , Astrócitos/metabolismo , Infecções por HIV/complicações , Transtornos Neurocognitivos/virologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , Peptídeos beta-Amiloides/metabolismo , Amiloidose/metabolismo , Animais , Encéfalo/metabolismo , Células Cultivadas , Infecções por HIV/metabolismo , HIV-1 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Macaca mulatta , Pessoa de Meia-Idade , Transtornos Neurocognitivos/metabolismo , Fragmentos de Peptídeos/metabolismo , RNA Longo não Codificante/metabolismo , Regulação para Cima
9.
Life Sci ; 253: 117745, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32376269

RESUMO

AIMS: Neuroinflammation and apoptosis play a crucial role in Parkinson's disease (PD) pathogenesis. Eupatilin is a lipophilic flavonoid isolated from Artemisia species and exerts anti-apoptotic and anti-inflammatory activities. In this study, we investigated the effects of Eupatilin on a mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MAIN METHODS: The rotarod test and traction test were constructed to examine the motor function. Immunofluorescent staining was performed to detect the expression of TH, Iba-1 and GFAP. Apoptosis was examined by the TUNEL assay. Real-time PCR was used to determine the mRNA expression and Western blot and ELISA were used to determine the protein expression. KEY FINDINGS: Eupatilin improved behavioral impairment caused by MPTP. A loss of TH positive neurons was observed in the substantia nigra pars compacta of MPTP-lesioned brain, while it was rescued by Eupatilin. Moreover, MPTP administration increased the cell number of microglia and astrocytes and the expression of inflammatory factors TNF-α, IL-1ß, and IL-6. Whereas Eupatilin suppressed the activation of neuroinflammation. Eupatilin also decreased cell apoptosis enhanced by MPTP/MPP+ exposure in vivo and in vitro. We further revealed that Eupatilin abolished MPTP-induced downregulation of IκBα expression and accumulation of p65 in the nuclear compartment. Besides, MPTP administration led to dephosphorylation of Akt and GSK-3ß, but it was restored by Eupatilin. SIGNIFICANCE: We demonstrate that Eupatilin alleviates behavioral impairment and dopaminergic neuron loss induced by MPTP through inhibition of neuroinflammation and apoptosis. Our research provides more evidence for Eupatilin as a potential preventative drug for PD.


Assuntos
Neurônios Dopaminérgicos/efeitos dos fármacos , Flavonoides/farmacologia , Degeneração Neural/tratamento farmacológico , Transtornos Parkinsonianos/tratamento farmacológico , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Apoptose/efeitos dos fármacos , Astrócitos/metabolismo , Comportamento Animal/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Inflamação/tratamento farmacológico , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Transtornos Parkinsonianos/fisiopatologia , Parte Compacta da Substância Negra/efeitos dos fármacos , Parte Compacta da Substância Negra/patologia , Teste de Desempenho do Rota-Rod
10.
Am J Physiol Endocrinol Metab ; 318(5): E765-E778, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32228320

RESUMO

We report here that the neuronal (pro)renin receptor (PRR), a key component of the brain renin-angiotensin system (RAS), plays a critical role in the central regulation of high-fat-diet (HFD)-induced metabolic pathophysiology. The neuronal PRR is known to mediate formation of the majority of angiotensin (ANG) II, a key bioactive peptide of the RAS, in the central nervous system and to regulate blood pressure and cardiovascular function. However, little is known about neuronal PRR function in overnutrition-related metabolic physiology. Here, we show that PRR deletion in neurons reduces blood pressure, neurogenic pressor activity, and fasting blood glucose and improves glucose tolerance without affecting food intake or body weight following a 16-wk HFD. Mechanistically, we found that a HFD increases levels of the PRR ligand (pro)renin in the circulation and hypothalamus and of ANG II in the hypothalamus, indicating activation of the brain RAS. Importantly, PRR deletion in neurons reduced astrogliosis and activation of the astrocytic NF-κB p65 (RelA) in the arcuate nucleus and the ventromedial nucleus of the hypothalamus. Collectively, our findings indicate that the neuronal PRR plays essential roles in overnutrition-related metabolic pathophysiology.


Assuntos
Astrócitos/metabolismo , Glicemia/metabolismo , Pressão Sanguínea/fisiologia , Hipotálamo/metabolismo , Inflamação/metabolismo , Neurônios/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Peso Corporal/fisiologia , Dieta Hiperlipídica , Ingestão de Alimentos/fisiologia , Camundongos , Camundongos Knockout , Receptores de Superfície Celular/genética , Renina/metabolismo
11.
Proc Natl Acad Sci U S A ; 117(16): 9082-9093, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32253301

RESUMO

Current multiple sclerosis (MS) medications are mainly immunomodulatory, having little or no effect on neuroregeneration of damaged central nervous system (CNS) tissue; they are thus primarily effective at the acute stage of disease, but much less so at the chronic stage. An MS therapy that has both immunomodulatory and neuroregenerative effects would be highly beneficial. Using multiple in vivo and in vitro strategies, in the present study we demonstrate that ursolic acid (UA), an antiinflammatory natural triterpenoid, also directly promotes oligodendrocyte maturation and CNS myelin repair. Oral treatment with UA significantly decreased disease severity and CNS inflammation and demyelination in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Importantly, remyelination and neural repair in the CNS were observed even after UA treatment was started on day 60 post immunization when EAE mice had full-blown demyelination and axonal damage. UA treatment also enhanced remyelination in a cuprizone-induced demyelination model in vivo and brain organotypic slice cultures ex vivo and promoted oligodendrocyte maturation in vitro, indicating a direct myelinating capacity. Mechanistically, UA induced promyelinating neurotrophic factor CNTF in astrocytes by peroxisome proliferator-activated receptor γ(PPARγ)/CREB signaling, as well as by up-regulation of myelin-related gene expression during oligodendrocyte maturation via PPARγ activation. Together, our findings demonstrate that UA has significant potential as an oral antiinflammatory and neural repair agent for MS, especially at the chronic-progressive stage.


Assuntos
Encefalomielite Autoimune Experimental/tratamento farmacológico , Imunomodulação/efeitos dos fármacos , Esclerose Múltipla/tratamento farmacológico , Remielinização/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/patologia , Cuprizona/toxicidade , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/patologia , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/imunologia , Oligodendroglia/patologia , PPAR gama/metabolismo , Triterpenos/uso terapêutico
12.
PLoS One ; 15(4): e0229520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236105

RESUMO

Therapeutic hypothermia (TH) is an attractive target for mild traumatic brain injury (mTBI) treatment, yet significant gaps in our mechanistic understanding of TH, especially at the cellular level, remain and need to be addressed for significant forward progress to be made. Using a recently-established 3D in-vitro neural hydrogel model for mTBI we investigated the efficacy of TH after compressive impact injury and established critical treatment parameters including target cooling temperature, and time windows for application and maintenance of TH. Across four temperatures evaluated (31.5, 33, 35, and 37°C), 33°C was found to be most neuroprotective after 24 and 48 hours post-injury. Assessment of TH administration onset time and duration showed that TH should be administered within 4 hours post-injury and be maintained for at least 6 hours for achieving maximum viability. Cellular imaging showed TH reduced the percentage of cells positive for caspases 3/7 and increased the expression of calpastatin, an endogenous neuroprotectant. These findings provide significant new insight into the biological parameter space that renders TH effective in mitigating the deleterious effects of cellular mTBI and provides a quantitative foundation for the future development of animal and preclinical treatment protocols.


Assuntos
Astrócitos/metabolismo , Lesões Encefálicas Traumáticas/terapia , Encéfalo , Hipotermia Induzida/métodos , Neurônios/metabolismo , Células-Tronco/metabolismo , Animais , Astrócitos/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Caspase 3/metabolismo , Caspase 7/metabolismo , Células Cultivadas , Neurônios/patologia , Fármacos Neuroprotetores/metabolismo , Ratos Sprague-Dawley , Células-Tronco/patologia
13.
Life Sci ; 252: 117642, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259600

RESUMO

AIMS: To determine whether ginsenoside Rg1 is involved in scratch wound healing through altered expression of related molecules in astrocytes and improved functional recovery after spinal cord injury (SCI). MATERIALS AND METHODS: Astrocytes were isolated from rats, followed by Rg1 treatment. The wound healing test was performed to observe the scratch wound healing in different groups. The expression of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), basic fibroblast growth factor (bFGF), and components of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway were detected by western blot. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the altered expression of laminin (LN) and fibronectin (FN). A revised Allen's method for the SCI model was performed, followed by Rg1 treatment. Then, functional scoring was conducted to evaluate the functional recovery. Hematoxylin-eosin (HE) staining showed changes in the void area. Finally, western blot assessed the expression of glial fibrillary acidic protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs). KEY FINDINGS: Rg1 mediated scratch wound healing through inducing an increased release of LN, FN, NGF, GDNF, and bFGF in vitro. Additionally, Rg1 activated the PI3K/Akt signaling pathway and promoted the functional recovery of hindlimb movement in rats. Furthermore, Rg1 significantly reduced the void area and downregulated the expression of GFAP and CSPGs. SIGNIFICANCE: Rg1 not only enhanced the scratch wound repair in vitro through the release of astroglial neurotrophic factors, adhesion factors, and inhibitory factors, but it also improved the functional recovery in vivo following SCI.


Assuntos
Astrócitos/efeitos dos fármacos , Ginsenosídeos/farmacologia , Traumatismos da Medula Espinal/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Animais , Astrócitos/metabolismo , Feminino , Masculino , Fatores de Crescimento Neural/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/fisiopatologia
14.
F1000Res ; 92020.
Artigo em Inglês | MEDLINE | ID: mdl-32269761

RESUMO

Astrocytes are the most abundant cell type in the central nervous system and have diverse functions in blood-brain barrier maintenance, neural circuitry formation and function, and metabolic regulation. To better understand the diverse roles of astrocytes, we will summarize what is known about astrocyte development and the challenges limiting our understanding of this process. We will also discuss new approaches and technologies advancing the field.


Assuntos
Astrócitos/citologia , Neurogênese , Barreira Hematoencefálica , Sistema Nervoso Central , Humanos
15.
Braz J Med Biol Res ; 53(4): e8604, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32294697

RESUMO

Maraba virus is a member of the genus Vesiculovirus of the Rhabdoviridae family that was isolated in 1983 from sandflies captured in the municipality of Maraba, state of Pará, Amazônia, Brazil. Despite 30 years having passed since its isolation, little is known about the neuropathology induced by the Maraba virus. Accordingly, in this study the histopathological features, inflammatory glial changes, cytokine concentrations, and nitric oxide activity in the encephalon of adult mice subjected to Maraba virus nostril infection were evaluated. The results showed that 6 days after intranasal inoculation, severe neuropathological-associated disease signs appeared, including edema, necrosis and pyknosis of neurons, generalized congestion of encephalic vessels, and intra- and perivascular meningeal lymphocytic infiltrates in several brain regions. Immunolabeling of viral antigens was observed in almost all central nervous system (CNS) areas and this was associated with intense microglial activation and astrogliosis. Compared to control animals, infected mice showed significant increases in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (INF)-γ, MCP-1, nitric oxide, and encephalic cytokine levels. We suggest that an exacerbated inflammatory response in several regions of the CNS of adult BALB/c mice might be responsible for their deaths.


Assuntos
Meningoencefalite/complicações , Estomatite Vesicular/complicações , Animais , Astrócitos/metabolismo , Brasil , Citocinas/análise , Modelos Animais de Doenças , Citometria de Fluxo , Masculino , Meningoencefalite/patologia , Camundongos , Camundongos Endogâmicos BALB C , Microglia/metabolismo , Óxido Nítrico/análise , Estomatite Vesicular/patologia , Vesiculovirus
16.
PLoS One ; 15(4): e0231752, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32330152

RESUMO

Astrocytes (AC) are the most abundant cells in the central nervous system. In the retina, astrocytes play important roles in the development and integrity of the retinal neurovasculature. Astrocytes dysfunction contributes to pathogenesis of a variety of neurovascular diseases including diabetic retinopathy. Recent studies have demonstrated the expression of Cyp1b1 in the neurovascular cells of the central nervous system including AC. We recently showed retinal AC constitutively express Cyp1b1, and global Cyp1b1-deficiency (Cyp1b1-/-) attenuates retinal ischemia-mediated neovascularization in vivo and the pro-angiogenic activity of retinal vascular cells in vitro. We also demonstrated that Cyp1b1 expression is a key regulator of retinal AC function. However, the underlying mechanisms involved need further investigation. Here we determined changes in the transcriptome profiles of Cyp1b1+/+ and Cyp1b1-/- retinal AC by RNA sequencing. We identified 585 differentially expressed genes, whose pathway enrichment analysis revealed the most significant pathways impacted in Cyp1b1-/- AC. These genes included those of axon guidance, extracellular matrix proteins and their receptors, cancer, cell adhesion molecules, TGF-ß signaling, and the focal adhesion modulation. The expression of a selected set of differentially expressed genes was confirmed by RT-qPCR analysis. To our knowledge, this is the first report of RNAseq investigation of the retinal AC transcriptome and the molecular pathways impacted by Cyp1b1 expression. These results demonstrated an important role for Cyp1b1 expression in the regulation of various retinal AC functions, which are important in neurovascular development and integrity.


Assuntos
Astrócitos/fisiologia , Adesão Celular/genética , Citocromo P-450 CYP1B1/metabolismo , Regulação da Expressão Gênica/fisiologia , Retina/fisiologia , Animais , Movimento Celular/genética , Células Cultivadas , Citocromo P-450 CYP1B1/genética , Feminino , Masculino , Camundongos , Camundongos Knockout , Cultura Primária de Células , RNA-Seq , Retina/citologia
17.
Neuron ; 105(6): 954-956, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32191856

RESUMO

In this issue of Neuron, Corkrum et al. (2020) demonstrate an unexpected role for dopamine D1 receptors on astrocytes located in the nucleus accumbens, a key structure of the brain's reward system. Activation of these receptors mediates dopamine-evoked depression of excitatory synaptic transmission, which contributes to amphetamine's psychomotor effects.


Assuntos
Dopamina , Núcleo Accumbens , Anfetamina , Astrócitos , Sinapses
18.
Nat Commun ; 11(1): 1220, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139688

RESUMO

Astrocytes, a major cell type found throughout the central nervous system, have general roles in the modulation of synapse formation and synaptic transmission, blood-brain barrier formation, and regulation of blood flow, as well as metabolic support of other brain resident cells. Crucially, emerging evidence shows specific adaptations and astrocyte-encoded functions in regions, such as the spinal cord and cerebellum. To investigate the true extent of astrocyte molecular diversity across forebrain regions, we used single-cell RNA sequencing. Our analysis identifies five transcriptomically distinct astrocyte subtypes in adult mouse cortex and hippocampus. Validation of our data in situ reveals distinct spatial positioning of defined subtypes, reflecting the distribution of morphologically and physiologically distinct astrocyte populations. Our findings are evidence for specialized astrocyte subtypes between and within brain regions. The data are available through an online database (https://holt-sc.glialab.org/), providing a resource on which to base explorations of local astrocyte diversity and function in the brain.


Assuntos
Astrócitos/citologia , Especificidade de Órgãos , Análise de Célula Única , Animais , Astrócitos/metabolismo , Sinalização do Cálcio , Forma Celular , Regulação da Expressão Gênica , Camundongos Endogâmicos C57BL , Neurogênese/genética , Especificidade de Órgãos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
19.
Nat Commun ; 11(1): 1277, 2020 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152301

RESUMO

Although supplemental oxygen is required to promote survival of severely premature infants, hyperoxia is simultaneously harmful to premature developing tissues such as in the retina. Here we report the effect of hyperoxia on central carbon metabolism in primary mouse Müller glial cells and a human Müller glia cell line (M10-M1 cells). We found decreased flux from glycolysis entering the tricarboxylic acid cycle in Müller cells accompanied by increased glutamine consumption in response to hyperoxia. In hyperoxia, anaplerotic catabolism of glutamine by Müller cells increased ammonium release two-fold. Hyperoxia induces glutamine-fueled anaplerosis that reverses basal Müller cell metabolism from production to consumption of glutamine.


Assuntos
Células Ependimogliais/metabolismo , Glutamina/metabolismo , Hiperóxia/metabolismo , Animais , Astrócitos/metabolismo , Isótopos de Carbono , Células Cultivadas , Células Endoteliais/metabolismo , Glucose/metabolismo , Glutaminase/metabolismo , Glicólise , Humanos , Metaboloma , Camundongos , Mitocôndrias/metabolismo , Modelos Biológicos , Oxirredução , Fosforilação , Complexo Piruvato Desidrogenase/metabolismo
20.
PLoS One ; 15(3): e0230335, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32163499

RESUMO

Organophosphates (OPs) induce acute and chronic neurotoxicity, primarily by inhibiting acetylcholinesterase (AChE) activity as well as by necrosis, and apoptosis. Butyrylcholinesterase (BuChE), an exogenous bioscavenger of OPs, can be used as a treatment for OP exposure. It is prerequisite to develop in vitro brain models that can study BuChE post-treatment for acute OP exposure. In this study, we developed a three-dimensional (3D) brain-on-chip platform with human induced pluripotent stem cell (iPSC)-derived neurons and astrocytes to simulate human brain behavior. The platform consists of two compartments: 1) a hydrogel embedded with human iPSC-derived GABAergic neurons and astrocytes and 2) a perfusion channel with dynamic medium flow. The brain tissue constructs were exposed to Malathion (MT) at various concentrations and then treated with BuChE after 20 minutes of MT exposure. Results show that the iPSC-derived neurons and astrocytes directly interacted and formed synapses in the 3D matrix, and that treatment with BuChE improved viability after MT exposure up to a concentration of 10-3 M. We conclude that the 3D brain-on-chip platform with human iPSC-derived brain cells is a suitable model to study the neurotoxicity of OP exposure and evaluate therapeutic compounds for treatment.


Assuntos
Astrócitos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Butirilcolinesterase/farmacologia , Inibidores da Colinesterase/toxicidade , Neurônios GABAérgicos/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Malation/antagonistas & inibidores , Astrócitos/citologia , Astrócitos/metabolismo , Encéfalo/citologia , Células Cultivadas , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Humanos , Malation/toxicidade
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