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1.
Chem Biol Interact ; 317: 108966, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32004531

RESUMO

Titanium dioxide nanoparticles (TiO2-NPs) are widely used in the food industry, cosmetics, personal care and paints among others. Through occupational exposure and daily consumption, and because of their small size, TiO2-NPs can enter the body through different routes such as oral, dermal and inhalation, and accumulate in multiple organs including the brain. TiO2-NPs cause severe damage to many cell types, however their effects in the central nervous system remain largely unexplored. Therefore, in the present study we determined the cytotoxic effect of TiO2-NPs on rat astrocytes. We tested the oxidant properties of TiO2-NPs through DTT depletion, and measured oxidative stress-induced damage in mitochondria, through oxidation of 2,7-dichlorodihydrofluorescein diacetate (H2DCFDA) and loss of mitochondrial membrane potential (ΔΨm) with Mitotracker Green FM. We further examined oxidative stress-derived responses such as IκB-α degradation by Western Blot, NF-κB translocation by EMSA, autophagy induction by LC3-II levels, and expression of the inflammasome protein NLRP3. TiO2-NPs showed high oxidant properties and induced strong oxidative stress in astrocytes following their internalization, causing mitochondrial damage detected by ΔΨm loss. Responses against oxidative damage such as NF-κB translocation and autophagy were induced and NLRP3 protein expression was downregulated, indicating lower inflammasome-mediated responses in astrocytes. These results support TiO2-NPs cytotoxicity in astrocytes, cells that play key roles in neuronal homeostasis and their dysfunction can lead to neurological disorders including cognitive impairment and memory loss.


Assuntos
Astrócitos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Astrócitos/metabolismo , Células Cultivadas , Regulação para Baixo , Nanopartículas Metálicas , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Ratos , Ratos Wistar , Titânio
2.
J Ethnopharmacol ; 246: 112165, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31445133

RESUMO

Blood-brain barrier (BBB) is a barrier which maintains the material exchange balance of brain microenvironment and could be destroyed by chronic stress (CS). Glucocorticoids (GCs) can mimic the chronic stress induced damage to BBB. GCs induced BBB trauma models in vitro and in vivo to explore the effects of the traditional medicine Xiao-Yao-San (XYS). In this research, we found CS could injure the BBB to change the biochemical index, which could be reversed by XYS in vitro. The abilities of cell proliferation, invasion, and the expression of tight junction related genes (Occludin, Claudin, JAM-1 and ZO-1) were suppressed by CS and the trauma could be reversed by XYS partly. It was showed that GRs interacted with Occludin directly and inhibited Occluding expression. In rats BBB trauma model, the GC content was deceased and BBB permeability was repaired by XYS. The expression of Occludin, Claudin, JAM-1 and ZO-1 were increased in the treatment of XYS. In our research, it shown that XYS affect the content of the GC and GR which interacted with Occludin directly for the first time. In addition, we also found that XYS could reduce BBB injury induced by CS via GR in BBB model in vitro. Therefore, it proves that XYS is a potential BBB repair medicine and may help to elucidate mechanism of brain pathology.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Fármacos Neuroprotetores/farmacologia , Estresse Fisiológico , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Masculino , Ratos Sprague-Dawley , Ratos Wistar , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Proteínas de Junções Íntimas/genética , Proteínas de Junções Íntimas/metabolismo , Regulação para Cima
3.
Toxicol Lett ; 318: 44-49, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31639409

RESUMO

Acrolein is a neurotoxin produced through lipid peroxidation in the brain affected by ischemic stroke, which results in neuronal cell injury and inflammation. However the mechanism underlying acrolein-induced brain inflammation remains unclear. Therefore we examined how acrolein leads to astrocytic inflammation. It was found that acrolein increased the levels of NLRP3 and cleaved caspase-1, which led to the maturation of interleukin-1ß (IL-1ß). ELISA assay results, which showed that acrolein increased the secreted IL-1ß, further supported acrolein-induced astrocytic inflammation. Acrolein increased ADAM10 protein levels and the cleavage of N-cadherin. The ADAM10 inhibitor, GI 254023X blocked N-cadherin cleavage by acrolein, suggesting that ADAM10 is an upstream of N-cadherin. Furthermore, we found that acrolein activated p38 MAPK and NF-κB p65, while pretreatment with p38 MAPK inhibitor, SB203580 and GI 254023X inhibited NF-κB p65 activation and NLRP3 inflammasome. This suggests that p38 MAPK mediates the activation of NF-κB p65, which is associated with NLRP3 expression. Finally, we showed that acrolein induced cell toxicity and decrease of EAAT1 expression, suggesting that acrolein may induce a loss of glutamate uptake function. In conclusion, we demonstrate that acrolein induces astrocytic inflammation through NLRP3 inflammasome, which is regulated by ADAM10 and attributed to p38 MAPK-activated NF-κB p65 activity.


Assuntos
Proteína ADAM10/metabolismo , Acroleína/toxicidade , Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encefalite/induzido quimicamente , Inflamassomos/efeitos dos fármacos , Proteína ADAM10/genética , Animais , Astrócitos/enzimologia , Astrócitos/patologia , Encéfalo/enzimologia , Encéfalo/patologia , Caderinas/metabolismo , Caspase 1/metabolismo , Linhagem Celular , Encefalite/enzimologia , Encefalite/patologia , Transportador 1 de Aminoácido Excitatório/metabolismo , Inflamassomos/metabolismo , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Chem Biol Interact ; 314: 108849, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610157

RESUMO

To provide novel insight into approaches designed to combat glioblastoma, the molecular details of the cytotoxicity of gamabufotalin, were investigated in the human glioblastoma cell line U-87. A dose-dependent cytotoxicity was observed in the cells, whereas no detectable toxicity was confirmed in mouse primary astrocytes. LDH leakage was only observed in the cells treated with a relatively high concentration (>80 ng/ml). Downregulation of the expression levels of Aurora B, cdc25A, cdc25C, cdc2, Cyclin B1 and survivin, and upregulation of the expression level of p21 were observed in treated cells and occurred in parallel with G2/M phase arrest. Treatment with gamabufotalin also downregulated the expression level of uPA, CA9, and upregulated the expression level of TIMP3, all of which are closely associated with invasion/metastasis. Autophagy induction was observed in the treated cells and the addition of wortmannin, a potent autophagy inhibitor, significantly rescued U-87 cells. These results indicate that gamabufotalin exhibits cytotoxicity against cancerous glial cells with high potency and selectivity through multiple cytotoxic signaling pathways. The activation of p38 MAPK pathway along with the upregulation of VEGF/VEGFR2 was observed in the treated cells, both of which are likely to be compensatory changes in response to gamabufotalin treatment. Intriguingly, a specific inhibitor of p38 MAPK enhanced the cytotoxicity of the drug, suggesting an important prosurvival role for p38 MAPK. We thus suggest that developing a new combination regimen of gamabufotalin plus a p38 MAPK inhibitor and/or inhibitors for VEGF/VEGFR could improve the efficacy of the drug, and may provide more therapeutic benefits to patients with glioblastoma.


Assuntos
Apoptose/efeitos dos fármacos , Bufanolídeos/farmacologia , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Autofagia/efeitos dos fármacos , Bufanolídeos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Wortmanina/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Neurochem Res ; 44(11): 2449-2459, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31571097

RESUMO

Manganese (Mn) overexposure is a public health concern due to its widespread industrial usage and the risk for environmental contamination. The clinical symptoms of Mn neurotoxicity, or manganism, share several pathological features of Parkinson's disease (PD). Biologically, Mn is an essential trace element, and Mn in the brain is preferentially localized in astrocytes. This review summarizes the role of astrocytes in Mn-induced neurotoxicity, specifically on the role of neurotransmitter recycling, neuroinflammation, and genetics. Mn overexposure can dysregulate astrocytic cycling of glutamine (Gln) and glutamate (Glu), which is the basis for Mn-induced excitotoxic neuronal injury. In addition, reactive astrocytes are important mediators of Mn-induced neuronal damage by potentiating neuroinflammation. Genetic studies, including those with Caenorhabditis elegans (C. elegans) have uncovered several genes associated with Mn neurotoxicity. Though we have yet to fully understand the role of astrocytes in the pathologic changes characteristic of manganism, significant strides have been made over the last two decades in deciphering the role of astrocytes in Mn-induced neurotoxicity and neurodegeneration.


Assuntos
Astrócitos/metabolismo , Intoxicação por Manganês/fisiopatologia , Manganês/toxicidade , Animais , Astrócitos/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Neurônios/metabolismo
6.
Nat Commun ; 10(1): 4830, 2019 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645570

RESUMO

Central nervous system (CNS) injuries persist for years, and currently there are no therapeutics that can address the complex injury cascade that develops over this time-scale. 17ß-estradiol (E2) has broad tropism within the CNS, targeting and inducing beneficial phenotypic changes in myriad cells following injury. To address the unmet need for vastly prolonged E2 release, we report first-generation poly(pro-E2) biomaterial scaffolds that release E2 at nanomolar concentrations over the course of 1-10 years via slow hydrolysis in vitro. As a result of their finely tuned properties, these scaffolds demonstrate the ability to promote and guide neurite extension ex vivo and protect neurons from oxidative stress in vitro. The design and testing of these materials reported herein demonstrate the first step towards next-generation implantable biomaterials with prolonged release and excellent regenerative potential.


Assuntos
Astrócitos/efeitos dos fármacos , Materiais Biocompatíveis , Estradiol/farmacologia , Estrogênios/farmacologia , Gânglios Espinais/efeitos dos fármacos , Crescimento Neuronal/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Fármacos do Sistema Nervoso Central/administração & dosagem , Fármacos do Sistema Nervoso Central/química , Fármacos do Sistema Nervoso Central/farmacologia , Implantes de Medicamento/química , Estradiol/administração & dosagem , Estradiol/química , Estrogênios/administração & dosagem , Estrogênios/química , Técnicas In Vitro , Macrófagos , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Polímeros/química , Cultura Primária de Células , Pró-Fármacos/administração & dosagem , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Ratos , Medula Espinal/citologia
7.
Medicine (Baltimore) ; 98(42): e17591, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31626131

RESUMO

BACKGROUND: Spinal cord ischemia-reperfusion injury (SCII) is a common complication of spinal surgery as well as thoracic and abdominal surgery. Acute cytotoxic edema is the key pathogenic alteration. Therefore, avoiding or decreasing cellular edema has become the major target for SCII treatment. METHODS: The antiedema activity of ginsenoside Rb1 on aquaporin (AQP) 4, nerve growth factor (NGF), and brain-derived neurotrophic factor expression was detected by western blot and real-time polymerase chain reaction under conditions of oxygen-glucose deprivation/reoxygenation (OGD/R) in a rat astrocyte model in vitro. In addition, the cellular membrane permeability of AQP4 overexpressing cells or AQP4 small interfering RNA-transfected cells was detected. RESULTS: Ginsenoside Rb1 significantly prevented OGD/R-induced AQP4 downregulation in rat astrocytes. In addition, ginsenoside Rb1 treatment or AQP4 overexpression in rat astrocytes significantly attenuated the OGD/R-induced increase of cellular membrane permeability. Moreover, ginsenoside Rb1 obviously prevented the OGD/R-induced decrease of NGF and BDNT expression in rat astrocytes. CONCLUSION: These findings demonstrate that ginsenoside Rb1 can relieve spinal cord edema and improve neurological function by increasing AQP4 expression.


Assuntos
Aquaporina 4/genética , Astrócitos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Ginsenosídeos/farmacologia , Glucose/metabolismo , Oxigênio/metabolismo , Traumatismo por Reperfusão/genética , Animais , Animais Recém-Nascidos , Aquaporina 4/biossíntese , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Western Blotting , Células Cultivadas , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , RNA/genética , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medula Espinal/metabolismo , Medula Espinal/patologia
8.
PLoS Biol ; 17(10): e3000492, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31626642

RESUMO

Naturally occurring cell death is a fundamental developmental mechanism for regulating cell numbers and sculpting developing organs. This is particularly true in the nervous system, where large numbers of neurons and oligodendrocytes are eliminated via apoptosis during normal development. Given the profound impact of death upon these two major cell populations, it is surprising that developmental death of another major cell type-the astrocyte-has rarely been studied. It is presently unclear whether astrocytes are subject to significant developmental death, and if so, how it occurs. Here, we address these questions using mouse retinal astrocytes as our model system. We show that the total number of retinal astrocytes declines by over 3-fold during a death period spanning postnatal days 5-14. Surprisingly, these astrocytes do not die by apoptosis, the canonical mechanism underlying the vast majority of developmental cell death. Instead, we find that microglia engulf astrocytes during the death period to promote their developmental removal. Genetic ablation of microglia inhibits astrocyte death, leading to a larger astrocyte population size at the end of the death period. However, astrocyte death is not completely blocked in the absence of microglia, apparently due to the ability of astrocytes to engulf each other. Nevertheless, mice lacking microglia showed significant anatomical changes to the retinal astrocyte network, with functional consequences for the astrocyte-associated vasculature leading to retinal hemorrhage. These results establish a novel modality for naturally occurring cell death and demonstrate its importance for the formation and integrity of the retinal gliovascular network.


Assuntos
Astrócitos/citologia , Morte Celular/genética , Microglia/citologia , Retina/citologia , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/fisiopatologia , Comunicação Celular , Contagem de Células , Toxina Diftérica/toxicidade , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Fator de Transcrição PAX2/genética , Fator de Transcrição PAX2/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Retina/efeitos dos fármacos , Retina/metabolismo , Hemorragia Retiniana/genética , Hemorragia Retiniana/metabolismo , Hemorragia Retiniana/fisiopatologia , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
9.
Mar Drugs ; 17(10)2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31590222

RESUMO

Currently, animal experiments in rodents are the gold standard for developmental neurotoxicity (DNT) investigations; however, testing guidelines for these experiments are insufficient in terms of animal use, time, and costs. Thus, alternative reliable approaches are needed for predicting DNT. We chose rat neural stem cells (rNSC) as a model system, and used a well-known neurotoxin, domoic acid (DA), as a model test chemical to validate the assay. This assay was used to investigate the potential neurotoxic effects of Ochratoxin A (OTA), of which the main target organ is the kidney. However, limited information is available regarding its neurotoxic effects. The effects of DA and OTA on the cytotoxicity and on the degree of differentiation of rat rNSC into astrocytes, neurons, and oligodendrocytes were monitored using cell-specific immunofluorescence staining for undifferentiated rNSC (nestin), neurospheres (nestin and A2B5), neurons (MAP2 clone M13, MAP2 clone AP18, and Doublecortin), astrocytes (GFAP), and oligodendrocytes (A2B5 and mGalc). In the absence of any chemical exposure, approximately 46% of rNSC differentiated into astrocytes and neurons, while 40.0% of the rNSC differentiated into oligodendrocytes. Both non-cytotoxic and cytotoxic concentrations of DA and OTA reduced the differentiation of rNSC into astrocytes, neurons, and oligodendrocytes. Furthermore, a non-cytotoxic nanomolar (0.05 µM) concentration of DA and 0.2 µM of OTA reduced the percentage differentiation of rNSC into astrocytes and neurons. Morphometric analysis showed that the highest concentrations (10 µM) of DA reduced axonal length. These indicate that low, non-cytotoxic concentrations of DA and OTA can interfere with the differentiation of rNSC.


Assuntos
Ácido Caínico/análogos & derivados , Células-Tronco Neurais/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Neurotoxinas/efeitos adversos , Ocratoxinas/efeitos adversos , Animais , Astrócitos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Ácido Caínico/efeitos adversos , Neurônios/efeitos dos fármacos , Oligodendroglia/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
10.
Int J Mol Sci ; 20(18)2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540372

RESUMO

Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the leading cause of dementia. The disease progression is associated with the build-up of amyloid plaques and neurofibrillary tangles in the brain. However, besides the well-defined lesions, the AD-related pathology includes neuroinflammation, compromised energy metabolism, and chronic oxidative stress. Likewise, the blood-brain barrier (BBB) dysfunction is suggested to be a cause and AD consequence. Accordingly, therapeutic targeting of the compromised BBB is a promising disease-modifying approach. We utilized a homozygous triple-transgenic mouse model of AD (3×Tg-AD) to assess the effects of L-norvaline on BBB integrity. We scrutinized the perivascular astrocytes and macrophages by measuring the immunopositive profiles in relation to the presence of ß-amyloid and compare the results with those found in wild-type animals. Typically, 3×Tg-AD mice display astroglia cytoskeletal atrophy, associated with the deposition of ß-amyloid in the endothelia, and declining nitric oxide synthase (NOS) levels. L-norvaline escalated NOS levels, then reduced rates of BBB permeability, amyloid angiopathy, microgliosis, and astrodegeneration, which suggests AD treatment agent efficacy. Moreover, results undergird the roles of astrodegeneration and microgliosis in AD-associated BBB dysfunction and progressive cognitive impairment. L-norvaline self-evidently interferes with AD pathogenesis and presents a potent remedy for angiopathies and neurodegenerative disorders intervention.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Barreira Hematoencefálica/efeitos dos fármacos , Valina/análogos & derivados , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/análise , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Barreira Hematoencefálica/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Angiopatia Amiloide Cerebral/tratamento farmacológico , Angiopatia Amiloide Cerebral/patologia , Modelos Animais de Doenças , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Valina/uso terapêutico
11.
Int J Mol Sci ; 20(18)2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31527507

RESUMO

Clinical and experimental data assumed a neuroprotective effect of the calcium channel blocker nimodipine. However, it has not been proven which neuronal or glial cell types are affected by nimodipine and which mechanisms underlie these neuroprotective effects. Therefore, the aim of this study was to investigate the influence of nimodipine treatment on the in vitro neurotoxicity of different cell types in various stress models and to identify the associated molecular mechanisms. Therefore, cell lines from Schwann cells, neuronal cells and astrocytes were pretreated for 24 h with nimodipine and incubated under stress conditions such as osmotic, oxidative and heat stress. The cytotoxicity was measured via the lactate dehydrogenase (LDH) activity of cell culture supernatant. As a result, the nimodipine treatment led to a statistically significantly reduced cytotoxicity in Schwann cells and neurons during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (p ≤ 0.05), when compared to the vehicle. The cytotoxicity of astrocytes was nimodipine-dependently reduced during osmotic (p ≤ 0.01), oxidative (p ≤ 0.001) and heat stress (not significant). Moreover, a decreased caspase activity as well as an increased proteinkinase B (AKT) and cyclic adenosine monophosphate response element-binding protein (CREB) phosphorylation could be observed after the nimodipine treatment under different stress conditions. These results demonstrate a cell type-independent neuroprotective effect of the prophylactic nimodipine treatment, which is associated with the prevention of stress-dependent apoptosis through the activation of CREB and AKT signaling pathways and the reduction of caspase 3 activity.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Nimodipina/farmacologia , Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Biomarcadores , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Ativação Enzimática , Resposta ao Choque Térmico/efeitos dos fármacos , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Transdução de Sinais
12.
Int J Nanomedicine ; 14: 6481-6495, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496698

RESUMO

Background: Despite the numerous pharmacological activities of quercetin, its biomedical application has been hampered, because of poor water solubility and low oral bioavailability. In the present study, we fabricated a novel form of quercetin-conjugated Fe3O4-ß-cyclodextrin (ßCD) nanoparticles (NPs), and the effect of these prepared NPs was evaluated in a chronic model of epilepsy. Methods: Quercetin-loaded NPs were prepared using an iron oxide core coated with ßCD and pluronic F68 polymer. The chronic model of epilepsy was developed by intraperitoneal injection of pentylenetetrazole (PTZ) at dose of 36.5 mg/kg every second day. Quercetin or its nanoformulation at doses of 25 or 50 mg/kg were administered intraperitoneally 10 days before PTZ injections and their applications continued 1 hour before each PTZ injection. Immunostaining was performed to evaluate the neuronal density and astrocyte activation of hippocampi. Results: Our data showed successful fabrication of quercetin onto Fe3O4-ßCD NPs. In comparison to free quercetin, quercetin NPs markedly reduced seizure behavior, neuronal loss, and astrocyte activation in a PTZ-induced kindling model. Conclusion: Overall, quercetin-Fe3O4-ßCD NPs might be regarded as an ideal therapeutic approach in epilepsy disorder.


Assuntos
Epilepsia/tratamento farmacológico , Nanopartículas de Magnetita/química , Quercetina/uso terapêutico , beta-Ciclodextrinas/química , Animais , Astrócitos/efeitos dos fármacos , Modelos Animais de Doenças , Hipocampo/patologia , Excitação Neurológica , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/ultraestrutura , Masculino , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Pentilenotetrazol/administração & dosagem , Quercetina/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
13.
J Neuroinflammation ; 16(1): 164, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31395092

RESUMO

BACKGROUND: Astrocytes respond to central nervous system (CNS) injury and disease by transforming to a reactive astrogliosis cell state that can contribute to either CNS dysfunction or repair. Neuroinflammation is a powerful driver of a harmful A1 astrogliosis phenotype associated with in vitro neurotoxicity and histopathology in human neurodegenerative diseases. Here we report a protocol for the rapid development of a human cell culture model of neuroinflammatory astrogliosis using induced pluripotent stem cells (iPSCs). METHODS: Using RNA sequencing and in vitro cell assays, we measured transcriptional and cellular effects of chronic exposure of human iPSC-derived astrocytes to the cytokines TNFα (tumor necrosis factor alpha) or IL-1ß (interleukin-1 beta). RESULTS: We show TNFα and IL-1ß induce pro-inflammatory gene signatures but by widely different magnitudes. TNFα treatment results in 606 differential expressed genes, the suppression of glutamate-uptake, and increased phagocytic activity in astrocyte cultures. In contrast, IL-1ß effects are attenuated to 33 differential expressed genes and no significant effects on glutamate-uptake or increased phagocytic activity. CONCLUSION: Our approach demonstrates a rapid tool for modeling neuroinflammatory human astrocytic responses in nervous system trauma and disease. In particular, we reveal a model for robust TNFα-induced human astrogliosis suitable for the study of neurotoxic A1 astrocytes.


Assuntos
Astrócitos/metabolismo , Sangue Fetal/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Mediadores da Inflamação/metabolismo , Fagocitose/fisiologia , Astrócitos/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Sangue Fetal/citologia , Sangue Fetal/efeitos dos fármacos , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Mediadores da Inflamação/farmacologia , Fagocitose/efeitos dos fármacos
14.
Transl Psychiatry ; 9(1): 181, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371697

RESUMO

Clozapine is an antipsychotic agent prescribed to psychotic patients exhibiting tolerance and/or resistance to the conventional antipsychotic medications that mainly drive monoamine antagonism. As the pharmacological fundamentals of its unique antipsychotic profile have been unrevealed, here, we attempted to obtain hints at this question. Here, we found that clozapine directly acts on ErbB kinases to downregulate epidermal growth factor (EGF)/neuregulin signaling. In cultured cell lines and cortical neurons, EGF-triggered ErbB1 phosphorylation was diminished by 30 µM clozapine, but not haloperidol, risperidone, or olanzapine. The neuregulin-1-triggered ErbB4 phosphorylation was attenuated by 10 µM clozapine and 30 µM haloperidol. We assumed that clozapine may directly interact with the ErbB tyrosine kinases and affect their enzyme activity. To test this assumption, we performed in vitro kinase assays using recombinant truncated ErbB kinases. Clozapine (3-30 µM) significantly decreased the enzyme activity of the truncated ErbB1, B2, and B4 kinases. Acute in vivo administration of clozapine (20 mg/kg) to adult rats significantly suppressed the basal phosphorylation levels of ErbB4 in the brain, although we failed to detect effects on basal ErbB1 phosphorylation. Altogether with the previous findings that quinazoline inhibitors for ErbB kinases harbor antipsychotic potential in animal models for schizophrenia, our present observations suggest the possibility that the micromolar concentrations of clozapine can attenuate the activity of ErbB receptor kinases, which might illustrate a part of its unique antipsychotic psychopharmacology.


Assuntos
Antipsicóticos/farmacologia , Encéfalo/efeitos dos fármacos , Clozapina/farmacologia , Fator de Crescimento Epidérmico/metabolismo , Neurregulinas/metabolismo , Proteínas Oncogênicas v-erbB/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Encéfalo/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Humanos , Masculino , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
15.
Biomed Pharmacother ; 118: 109299, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31387001

RESUMO

We have recently demonstrated that the neurosteroid-metabolizing enzyme, cytochrome P450c17 is increased in spinal astrocytes contributing to the development of mechanical allodynia in chronic constriction injury (CCI)-induced neuropathic mice. However, the mechanisms by which spinal P450c17 modulates pathological changes in astrocytes remain unclear. In this study we investigated whether P450c17 modulates astrocyte activation and whether this process is mediated by spinal p38 mitogen-activated protein kinase phosphorylation ultimately leading to the development of mechanical allodynia in CCI mice. Sciatic nerve injury induced a significant increase in glial fibrillary acidic protein (GFAP) expression in the superficial dorsal horn (SDH, laminae I-II) and nucleus proprius (NP, laminae III-IV) regions of the spinal cord dorsal horn. Repeated daily (from days 0-3 post-surgery) intrathecal administration of the P450c17 inhibitor, ketoconazole (10 nmol) significantly inhibited the CCI-induced increase in GFAP-immunoreactivity, but had no effect on the CCI-induced increase in Iba-1-immunoreactivity. In addition, intrathecal administration of ketoconazole significantly inhibited the CCI-induced increase in p38 phosphorylation, while the levels of ERK and JNK phosphorylation remained unchanged. The CCI-induced development of mechanical allodynia was attenuated by administration of either ketoconazole (10 nmol) or the p38 MAPK inhibitor, SB203580 (5 nmol). Administration of a sub-effective dose of SB203580 (0.5 nmol) potentiated the pharmacological effect of ketoconazole (1 nmol) on spinal GFAP-immunostaining, as well as, the development of mechanical allodynia following CCI. Collectively these data suggest that spinal P450c17 activates astrocytes via p38 phosphorylation, ultimately leading to the development of mechanical allodynia in a model of peripheral neuropathy.


Assuntos
Astrócitos/enzimologia , Neuralgia/enzimologia , Neuralgia/patologia , Medula Espinal/patologia , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Constrição Patológica , Modelos Animais de Doenças , Hiperalgesia/complicações , Hiperalgesia/patologia , Imidazóis/farmacologia , Cetoconazol/administração & dosagem , Cetoconazol/farmacologia , Vértebras Lombares/enzimologia , Vértebras Lombares/patologia , Masculino , Camundongos , Microglia/efeitos dos fármacos , Microglia/patologia , Fosforilação/efeitos dos fármacos , Piridinas/farmacologia , Corno Dorsal da Medula Espinal/enzimologia , Corno Dorsal da Medula Espinal/patologia , Esteroide 17-alfa-Hidroxilase/metabolismo
16.
Molecules ; 24(15)2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31387223

RESUMO

Ozone is the most oxidant tropospheric pollutant gas, causing damage through the formation of reactive oxygen and nitrogen species. Reactive species induce the nuclear factor-kappa B (NF-κB) activation leading to neuroinflammation characterized by astrocytosis, microgliosis, and apoptotic cell death. There is interest in evaluating the pharmacological activity of natural antioxidants to confer neuroprotection against the damage caused by ozone in highly polluted cities. Curcumin has been proven to exert a protective action in the central nervous system (CNS) of diverse experimental models, with no side effects. The aim of this work is to evaluate the effect of curcumin in a preventive and therapeutic manner against the astrocytosis, microgliosis, and apoptosis induced by ozone in rat hippocampus. Fifty Wistar rats were distributed into five experimental groups: The intact control, curcumin fed control, ozone-exposed group, and the preventive and therapeutic groups receiving the curcumin supplementation while exposed to ozone. Ozone caused astrocytosis and microgliosis, as well as apoptosis in the hippocampus. Meanwhile, curcumin was able to decrease the activation of microglia and astrocytes, and apoptotic cell death in both periods of exposure. Therefore, we propose that curcumin could be used as a molecule capable of counteracting the damage caused by ozone in the CNS.


Assuntos
Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Astrócitos/efeitos dos fármacos , Curcumina/farmacologia , Microglia/efeitos dos fármacos , Ozônio/efeitos adversos , Animais , Astrócitos/metabolismo , Biomarcadores , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/patologia , Imuno-Histoquímica , Microglia/metabolismo , Fármacos Neuroprotetores/farmacologia , Oxidantes Fotoquímicos/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Ratos
17.
J Agric Food Chem ; 67(34): 9618-9629, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31381342

RESUMO

Astrocytes provide nutritional support, regulate inflammation, and perform synaptic functions in the human brain. Although butylated hydroxyanisole (BHA) is a well-known antioxidant, several studies in animals have indicated BHA-mediated liver toxicity, retardation in reproductive organ development and learning, and sleep deficit. However, the specific effects of BHA on human astrocytes and the underlying mechanisms are yet unclear. Here, we investigated the antigrowth effects of BHA through cell cycle arrest and downregulation of regulatory protein expression. The typical cell proliferative signaling pathways, phosphoinositide 3-kinase/protein kinase B and extracellular signal-regulated kinase 1/2, were downregulated in astrocytes after BHA treatment. BHA increased the levels of pro-apoptotic proteins, such as BAX, cytochrome c, cleaved caspase 3, and cleaved caspase 9, and decreased the level of anti-apoptotic protein BCL-XL. It also increased the cytosolic calcium level and the expression of endoplasmic reticulum stress proteins. Treatment with BAPTA-AM, a calcium chelator, attenuated the increased levels of ER stress proteins and cleaved members of the caspase family. We further performed an in vivo evaluation of the neurotoxic effect of BHA on zebrafish embryos and glial fibrillary acidic protein, a representative astrocyte biomarker, in a gfap:eGFP zebrafish transgenic model. Our results provide clear evidence of the potent cytotoxic effects of BHA on human astrocytes, which lead to disruption of the brain and nerve development.


Assuntos
Astrócitos/efeitos dos fármacos , Hidroxianisol Butilado/toxicidade , Cálcio/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Neurotoxinas/toxicidade , Animais , Astrócitos/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular , Citocromos c/metabolismo , Citosol/efeitos dos fármacos , Citosol/metabolismo , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra
18.
Int Immunopharmacol ; 75: 105770, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377588

RESUMO

Up-regulated glutaminyl cyclase (QC) plays crucial roles in the initiation of Alzheimer's disease (AD) and kinds of chronic diseases mediated by inflammation. QC is supposed as a novel target for the therapeutics of these diseases. Here, we explored the anti-inflammation effects of diphenyl conjugated imidazole (DPCI) derivatives which were previously designed, synthesized and evaluated as novel QC inhibitors for AD treatment in our lab. Behavioral tests, QC activity assay, histology and ELISA analysis were conducted on both AD and lipopolysaccharides (LPS)-induced inflammatory model mice. It was shown that behavioral and cognitive performance in AD mice treated with the selected compound DPCI-23 were enhanced notably. QC activity, the formation of pE-Aß and Aß plaques and the activation of astrocytes and microglia cells in AD mice brains were inhibited, and the levels of inflammatory factors such as IL-6, IL-1ß and TNF-α in serum were reduced remarkably. Furthermore, elevated QC activity in inflammatory mice brains was also inhibited, and levels of IL-1ß, IL-1ra, TNF-α and CCL2 in serum, kidneys and brains together with the activated astrocytes and microglia cells in brains were all repressed significantly after the treatment of DPCI-23. These findings observed in this research demonstrated the anti-inflammation potency of DPCI-23 in modal of AD and inflammation by inhibiting QC activity, and may contribute to the employment of QC inhibitors for the prevention and treatment of AD and other inflammatory diseases.


Assuntos
Doença de Alzheimer/imunologia , Aminoaciltransferases/antagonistas & inibidores , Anti-Inflamatórios/farmacologia , Imidazóis/farmacologia , Animais , Astrócitos/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Citocinas/sangue , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Rim/efeitos dos fármacos , Rim/imunologia , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/efeitos dos fármacos
19.
Gen Physiol Biophys ; 38(5): 417-425, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31411572

RESUMO

The brain has long been known as a dimorphic organ and as a target of estrogen. Neurogenesis, including proliferation and differentiation of neural stem cells (NSCs), could be stimulated and regulated by estrogen. However, the dose and timing of estrogen treatment is controversial, and the underlying mechanism remains unclear. In this study, we tested the effects of various estrogen doses on the neurogenesis of NSCs derived from Sprague-Dawley rat embryos. First, we identified that the estrogen receptor-ERα, ERß and GPR30 were highly expressed in NSCs. The results from cell cycle and Western blot analyses revealed that 10 nM 17ß-estradiol (E2) treatment for 3 days significantly increased NSCs proliferation of and p-ERK1/2 expression level but that 50 nM E2 exposure markedly decreased NSCs proliferation and p-ERK1/2 expression level. According to immunofluorescence staining and Western blot analyses, 10 nM E2 treatment for 7 days significantly stimulated NSCs to differentiate into neurons and inhibited their differentiation into astrocytes. These results demonstrate that NSCs are a target of estrogen and that an appropriate dose of E2 (10 nM) can significantly increase the proliferation of NSCs and stimulate NSCs to differentiate into neurons, which contributes to knowledge regarding the regulatory effects of estrogens on neurogenesis.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Estrogênios/administração & dosagem , Estrogênios/farmacologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Animais , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Neurônios/citologia , Neurônios/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores Estrogênicos/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo
20.
BMC Complement Altern Med ; 19(1): 215, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412844

RESUMO

BACKGROUND: Mounting evidence indicates that the cerebral cortex is an important physiological system of emotional activity, and its dysfunction may be the main cause of stress. Glutamate is the primary excitatory neurotransmitter in the central nervous system (CNS), which initiates rapid signal transmission in the synapse before its reuptake into the surrounding glia, specifically astrocytes (ASTs). The astrocytic excitatory amino acid transporters 1 (EAAT1) and 2 (EAAT2) are the major transporters that take up synaptic glutamate to maintain optimal extracellular glutamic levels, thus preventing accumulation in the synaptic cleft and ensuing excitotoxicity. Growing evidence has shown that excitotoxicity is associated with depression. Therefore, we hypothesized that the underlying antidepressant-like mechanism of Xiaoyaosan (XYS), a Chinese herbal formula, may be related to the regulation of astrocytic EAATs. Therefore, we studied the antidepressant mechanism of XYS on the basis of EAAT dysfunction in ASTs. METHODS: Eighty adult C57BL/6 J mice were randomly divided into 4 groups: a control group, a chronic unpredictable mild stress (CUMS) group, a Xiaoyaosan (XYS) treatment group and a fluoxetine hydrochloride (Flu) treatment group. Except for the control group, mice in the other groups all received chronic unpredictable mild stress for 21 days. Mice in the control and CUMS groups received gavage administration with 0.5 mL of normal saline (NS) for 21 days, and mice in the XYS and Flu treatment groups were administered dosages of 0.25 g/kg/d and 2.6 mg/kg/d by gavage. The effects of XYS on the depressive-like behavioral tests, including the open field test (OFT), forced swimming test (FST) and sucrose preference test (SPT), were examined. The glutamate (Glu) concentrations of the prefrontal cortex (PFC) were detected with colorimetry. The morphology of neurons in the PFC was observed by Nissl staining. The expression of glial fibrillary acidic protein (GFAP), NeuN, EAAT1 and EAAT2 proteins in the PFC of mice was detected by using Western blotting and immunohistochemistry. Quantitative real-time PCR (qPCR) was used to detect the expression of the GFAP, NeuN, EAAT1 and EAAT2 genes in the PFC of mice. RESULTS: The results of behavioral tests showed that CUMS-induced mice exhibited depressive-like behavior, which could be improved in some tests with XYS and Flu treatment. Immunohistochemistry and Western blot analysis showed that the protein levels of GFAP, NeuN, EAAT1 and EAAT2 in the PFC of CUMS mice were significantly lower than those in the control group, and these changes could be reversed by XYS and Flu. The results of qPCR analysis showed that the expression of GFAP, NeuN, EAAT1 and EAAT2 mRNAs in the PFC of CUMS mice was not significantly changed, with the exception of EAAT2, compared with that of the control group, while the expression of the above mRNAs was significantly higher in the XYS and Flu groups than that in the CUMS group. CONCLUSION: XYS may exert antidepressant-like effects by improving the functions of AST and EAATs and attenuating glutamate-induced neuronal damage in the frontal cortex.


Assuntos
Antidepressivos/administração & dosagem , Astrócitos/efeitos dos fármacos , Depressão/tratamento farmacológico , Medicamentos de Ervas Chinesas/administração & dosagem , Transportador 1 de Aminoácido Excitatório/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Córtex Pré-Frontal/citologia , Animais , Comportamento Animal , Depressão/genética , Depressão/metabolismo , Modelos Animais de Doenças , Transportador 1 de Aminoácido Excitatório/genética , Transportador 2 de Aminoácido Excitatório/genética , Proteína Glial Fibrilar Ácida/metabolismo , Ácido Glutâmico/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Córtex Pré-Frontal/efeitos dos fármacos
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