Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
ACS Appl Mater Interfaces ; 16(15): 19615-19624, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38587106

RESUMO

Introducing component-selective polymer chains onto the surface of a particle is an effective approach to improve the compatibilization efficiency of a particle-based compatibilizer. In this study, two particles with different kinds of component-selective polymer chains that have the same length and similar density but different graft locations were synthesized and their compatibilization effects were comparatively investigated. It was found that compared with the particle with homogeneous PMMA and PP grafts (R-P), the particle with a hemisphere of poly(methyl methacrylate) (PMMA) grafts and other hemisphere of polypropylene (PP) chains (J-P) showed a better compatibilization effect under equal loadings, although both particles exhibited high efficiency. The better compatibilization effect of particles with Janus grafts may be attributed to the stronger entanglements between grafted polymer chains and selective individual components. This work suggests that optimizing the graft location of a particle is an effective strategy for improving its compatibilization efficiency and helpful for the design of advanced particle compatibilizers.

2.
Curr Neuropharmacol ; 21(3): 621-650, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35794770

RESUMO

As the first peripheral immune cells to enter the brain after ischemic stroke, neutrophils are important participants in stroke-related neuroinflammation. Neutrophils are quickly mobilized from the periphery in response to a stroke episode and cross the blood-brain barrier to reach the ischemic brain parenchyma. This process involves the mobilization and activation of neutrophils from peripheral immune organs (including the bone marrow and spleen), their chemotaxis in the peripheral blood, and their infiltration into the brain parenchyma (including disruption of the blood-brain barrier, inflammatory effects on brain tissue, and interactions with other immune cell types). In the past, it was believed that neutrophils aggravated brain injuries through the massive release of proteases, reactive oxygen species, pro-inflammatory factors, and extracellular structures known as neutrophil extracellular traps (NETs). With the failure of early clinical trials targeting neutrophils and uncovering their underlying heterogeneity, our view of their role in ischemic stroke has become more complex and multifaceted. As neutrophils can be divided into N1 and N2 phenotypes in tumors, neutrophils have also been found to have similar phenotypes after ischemic stroke, and play different roles in the development and prognosis of ischemic stroke. N1 neutrophils are dominant during the acute phase of stroke (within three days) and are responsible for the damage to neural structures via the aforementioned mechanisms. However, the proportion of N2 neutrophils gradually increases in later phases, and this has a beneficial effect through the release of anti-inflammatory factors and other neuroprotective mediators. Moreover, the N1 and N2 phenotypes are highly plastic and can be transformed into each other under certain conditions. The pronounced differences in their function and their high degree of plasticity make these neutrophil subpopulations promising targets for the treatment of ischemic stroke.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Neutrófilos/metabolismo , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , Acidente Vascular Cerebral/tratamento farmacológico , Encéfalo/patologia , Isquemia Encefálica/metabolismo
3.
Nat Sci Sleep ; 13: 1441-1448, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34466044

RESUMO

Creutzfeldt-Jakob disease (CJD) subtypes are difficult to identify due to the heterogeneity of the clinical phenotype, and early accurate identification of sporadic CJD (sCJD) subtypes aids prognosis prediction. Currently, the diagnosis of sCJD subtypes is mainly based on brain tissue biopsy or autopsy. In this report, we present a case of confirmed sCJD initially presenting as insomnia. We described detailed information including clinical, electroencephalographic, polysomnographic, positron emission tomography-computed tomographic and other neuroimaging findings, cerebrospinal fluid biomarkers, skin tissue biopsy and whole blood PRNP gene sequencing in this patient. An extensive literature search was performed in order to better understand the diagnosis of various sCJD subtypes, particularly the thalamic form, sCJDMM2 (also known as sporadic fatal insomnia). Our study highlights sporadic fatal insomnia as a differential diagnosis of sCJD.

4.
ASN Neuro ; 13: 17590914211037505, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34463559

RESUMO

Ischemic stroke is one of the main causes of high morbidity, mortality, and disability worldwide; however, the treatment methods are limited and do not always achieve satisfactory results. The pathogenesis of ischemic stroke is complex, defined by multiple mechanisms; among them, programmed death of neuronal cells plays a significant role. Ferroptosis is a novel type of regulated cell death characterized by iron redistribution or accumulation and increased lipid peroxidation in the membrane. Ferroptosis is implicated in many pathological conditions, such as cancer, neurodegenerative diseases, and ischemia-reperfusion injury. In this review, we summarize current research findings on ferroptosis, including possible molecular mechanisms and therapeutic applications of ferroptosis regulators, with a focus on the involvement of ferroptosis in the pathogenesis and treatment of ischemic stroke. Understanding the role of ferroptosis in ischemic stroke will throw some light on the development of methods for diagnosis, treatment, and prevention of this devastating disease.


Assuntos
Isquemia Encefálica , Ferroptose , AVC Isquêmico , Acidente Vascular Cerebral , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Humanos , Peroxidação de Lipídeos , Acidente Vascular Cerebral/tratamento farmacológico
5.
Front Neurol ; 12: 679302, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34276539

RESUMO

Mitochondrial diseases are a group of common inherited disorders caused by mutations in nuclear DNA or mitochondrial DNA (mtDNA); the clinical phenotype of diseases caused by mutant mtDNA is challenging owing to heteroplasmy of mtDNA and may delay diagnosis and treatment. Herein, we report the case of an adult male who slowly developed epilepsy, ataxia, dystonia, impaired cognition, and hearing impairment over 14 years in the absence of clinical myopathy. His lactate level was normal. Brain computed tomography showed calcifications of the bilateral basal ganglia, thalamus, and cerebellar dentate nuclei. Magnetic resonance imaging revealed multiple lesions in the bilateral internal capsule and periventricular areas, which were hypointense on T1-weighted images and hyperintense on T2-weighted images. The first blood genetic test result was negative. Two years later, a muscle biopsy was performed. Succinate dehydrogenase (SDH) staining showed several ragged blue fibers and atypical strongly SDH-reactive vessels. Cytochrome C oxidase (COX) staining revealed abundant COX-deficient fibers. mtDNA testing of blood and muscle revealed a rare m.5549G>A mutation in the MT-TW gene. It was heteroplasmic, with 5.4% mutant mtDNA in the blood and 61.5% in the muscle. The patient was diagnosed with mitochondrial encephalomyopathy and treated with levetiracetam instead of valproate to reduce possible mitochondrial toxicity. After receiving anti-epileptic drugs and mitochondrial supplements, the patient remained clinically stable. For mitochondrial disease, when mutant mtDNA is not detected in blood, muscle biopsy should be performed in routine analysis, and it should be genetically tested, even if there are no manifestations of myopathy.

6.
Aging (Albany NY) ; 13(12): 16620-16636, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34170848

RESUMO

Dopamine receptor, a polypeptide chain composed of 7 hydrophobic transmembrane regions, is a new and vital drug target, especially Dopamine receptor 2(D2). Targeting dopamine receptors, Dopamine receptor agonists are a class of drugs similar in function and structure to dopamine and can directly act on dopamine receptors and activate it. Clinically, Dopamine receptor agonist drugs have achieved significant therapeutic effects on prolactinoma and Parkinson's Disease. In the study, we virtually screened a series of potential effective agonists of Dopamine receptor by computer techniques. Firstly, we used the Molecular Docking (LibDock) step to screen out some molecules that can dock well with the protein. Then, analysis of toxicity prediction and ADME (adsorption, distribution, metabolism and excretion) were carried out. More precise molecular docking (CDOCKER) and 3-Dimensional Quantitative Structure-Activity Relationship Modeling Study(3D-QSAR) pharmacophore generation were implemented to research and explore these compounds' binding mechanism with Dopamine receptor. Last but not least, to assess compound's binding stabilities, we carried out a molecular dynamic analysis. As the results show, two compounds (ZINC000008860530 and ZINC000004096987) from the small molecule database (ZINC database) were potential effective agonists of Dopamine receptor. These two compounds can combine with Dopamine receptor with higher affinity and proved to be no toxic. The cell experiment showed that two compounds could inhibit the proliferation and PRL secretion of MMQ cells (pituitary tumor cells). Thus, this study provided valuable information about Dopamine receptor agonist-based drug discovery. So, this study will benefit patients with prolactinoma and Parkinson's disease a lot.


Assuntos
Produtos Biológicos/química , Produtos Biológicos/farmacologia , Agonistas de Dopamina/química , Agonistas de Dopamina/farmacologia , Simulação de Acoplamento Molecular , Receptores Dopaminérgicos/química , Produtos Biológicos/análise , Produtos Biológicos/toxicidade , Bromocriptina/química , Bromocriptina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Agonistas de Dopamina/análise , Agonistas de Dopamina/toxicidade , Avaliação Pré-Clínica de Medicamentos , Humanos , Ligação de Hidrogênio , Ligantes , Simulação de Dinâmica Molecular , Prolactina/metabolismo
7.
Front Neurol ; 12: 546481, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34025545

RESUMO

Posterior reversible encephalopathy syndrome (PRES) is a relatively rare clinical disease, characterized by reversible subcortical vasogenic edema. Here, we present the first reported case of PRES induced by anlotinib, a multi-target tyrosine kinase inhibitor. A 56-year-old female patient with lung adenocarcinoma and bone metastasis experienced hypertension and mental confusion when she received anti-angiogenesis treatment. PRES was diagnosed after magnetic resonance of the patient's brain revealed hyperintensities bilaterally around the cerebellum, pons, fronto-parieto-occipital areas, and corona radiate. Diffusion-weighted imaging showed hyperintensities bilaterally in the parieto-occipital cortical regions. Subsequently, the patient was diagnosed with PRES, and remission was achieved with anti-hypertensive drugs. Six cases of rare adverse effects induced by anlotinib were reviewed in the literature. Since anlotinib has been widely applied as a novel third-line treatment in patients with non-small-cell lung cancer, the association between PRES and anlotinib would benefit neurologists and oncologists in future diagnoses and treatment.

8.
J Neurol ; 268(7): 2402-2419, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32140865

RESUMO

Axonal variants of Guillain-Barré syndrome (GBS) mainly include acute motor axonal neuropathy, acute motor and sensory axonal neuropathy, and pharyngeal-cervical-brachial weakness. Molecular mimicry of human gangliosides by a pathogen's lipooligosaccharides is a well-established mechanism for Campylobacter jejuni-associated GBS. New triggers of the axonal variants of GBS (axonal GBS), such as Zika virus, hepatitis viruses, intravenous administration of ganglioside, vaccination, and surgery, are being identified. However, the pathogenetic mechanisms of axonal GBS related to antecedent bacterial or viral infections other than Campylobacter jejuni remain unknown. Currently, autoantibody classification and serial electrophysiology are cardinal approaches to differentiate axonal GBS from the prototype of GBS, acute inflammatory demyelinating polyneuropathy. Newly developed technologies, including metabolite analysis, peripheral nerve ultrasound, and feature selection via artificial intelligence are facilitating more accurate diagnosis of axonal GBS. Nevertheless, some key issues, such as genetic susceptibilities, remain unanswered and moreover, current therapies bear limitations. Although several therapies have shown considerable benefits to experimental animals, randomized controlled trials are still needed to validate their efficacy.


Assuntos
Infecções por Campylobacter , Campylobacter jejuni , Síndrome de Guillain-Barré , Infecção por Zika virus , Zika virus , Animais , Inteligência Artificial , Autoanticorpos , Infecções por Campylobacter/complicações , Gangliosídeos , Síndrome de Guillain-Barré/terapia , Humanos
9.
Mol Neurobiol ; 58(1): 21-33, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32889654

RESUMO

Alteration in cellular prion protein (PrPC) localization on the cell surface through mediation of the glycosylphosphatidylinositol (GPI) anchor has been reported to dramatically affect the formation and infectivity of its pathological isoform (PrPSc). A patient with Gerstmann-Sträussler-Scheinker (GSS) syndrome was previously found to have a nonsense heterozygous PrP-Q227X mutation resulting in an anchorless PrP. However, the allelic origin of this anchorless PrPSc and cellular trafficking of PrPQ227X remain to be determined. Here, we show that PrPSc in the brain of this GSS patient is mainly composed of the mutant but not wild-type PrP (PrPWt), suggesting pathological PrPQ227X is incapable of recruiting PrPWt in vivo. This mutant anchorless protein, however, is able to recruit PrPWt from humanized transgenic mouse brain but not from autopsied human brain homogenates to produce a protease-resistant PrPSc-like form in vitro by protein misfolding cyclic amplification (PMCA). To further investigate the characteristics of this mutation, constructs expressing human PrPQ227X or PrPWt were transfected into neuroblastoma cells (M17). Fractionation of the M17 cells demonstrated that most PrPWt is recovered in the cell lysate fraction, while most of the mutant PrPQ227X is recovered in the medium fraction, consistent with the results obtained by immunofluorescence microscopy. Two-dimensional gel-electrophoresis and Western blotting showed that cellular PrPQ227X spots clustered at molecular weights of 22-25 kDa with an isoelectric point (pI) of 3.5-5.5, whereas protein spots from the medium are at 18-26 kDa with a pI of 7-10. Our findings suggest that the role of GPI anchor in prion propagation between the anchorless mutant PrP and wild-type PrP relies on the cellular distribution of the protein.


Assuntos
Códon sem Sentido/genética , Doença de Gerstmann-Straussler-Scheinker/genética , Príons/genética , Adulto , Animais , Anticorpos/metabolismo , Autopsia , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Centrifugação com Gradiente de Concentração , Feminino , Glicosilação , Humanos , Camundongos Transgênicos , Príons/química , Agregados Proteicos , Dobramento de Proteína
10.
Medicine (Baltimore) ; 99(23): e20059, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32501968

RESUMO

BACKGROUND: Salvianolic acids (SA) has been widely used for the treatment of acute cerebral infarction (ACI) combined with basic western medicine therapy in China. This study was aimed to evaluate the efficacy and safety of SA on ACI treatment and its influence on neurological functions, activity of daily living, and cognitive functions. METHODS: We retrieved related articles from PubMed, the Cochrane Center Controlled Trials Register, EMBASE, Medline, Ovid, Chinese National Knowledge Infrastructure, Chinese Biomedical Literature Database, and Wanfang Database without date and language restrictions. Finally, 58 randomized controlled trials were included from 239 retrieved records. Two researchers extracted the basic information and data from included articles and assessed the quality and analysis of data by using Review Manager 5.3. RESULTS: The administration of SA significantly increased the total clinical effective rate of ACI treatment (P < .001) and improved the National Institute of Health Stroke Scale scores, modified Rankin Scale scores, and Barthel Index scores after treatment and 3 months after ACI (P < .05). The activities of daily living scores in the SA group were significantly increased after treatment (P < .001), whereas they were remarkably decreased 3 months after ACI (P < .001) compared with that in the control group. Besides, SA profoundly promoted the recovery of Montreal Cognitive Assessment scores (P < .001). However, the use of SA increased the risk of adverse events occurrence (P = .007). CONCLUSION: SA combined with basic western medicine treatment could promote neurological functions, daily living activities, and cognitive functions recovery of ACI patients. Although SA increased the risk of adverse events occurrence, these adverse events were easily controlled or disappeared spontaneously.


Assuntos
Alcenos/uso terapêutico , Infarto Cerebral/tratamento farmacológico , Polifenóis/uso terapêutico , Atividades Cotidianas , Doença Aguda , Alcenos/administração & dosagem , Alcenos/efeitos adversos , Cognição , Terapia Combinada , Humanos , Polifenóis/administração & dosagem , Polifenóis/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Metanálise como Assunto
11.
J Neurol Sci ; 413: 116775, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32197118

RESUMO

The development of effective treatment for ischemic stroke, which is a common cause of morbidity and mortality worldwide, remains an unmet goal because the current first-line treatment management interventional therapy has a strict time window and serious complications. In recent years, a growing body of evidence has shown that the elevation of intracellular and extracellular cyclic adenosine monophosphate (cAMP) alleviates brain damage after ischemic stroke by attenuating neuroinflammation in the central nervous system and peripheral immune system. In the central nervous system, upregulated intracellular cAMP signaling can alleviate immune-mediated damage by restoring neuronal morphology and function, inhibiting microglia migration and activation, stabilizing the membrane potential of astrocytes and improving the cellular functions of endothelial cells and oligodendrocytes. Enhancement of the extracellular cAMP signaling pathway can improve neurological function by activating the cAMP-adenosine pathway to reduce immune-mediated damage. In the peripheral immune system, cAMP can act on various immune cells to suppress peripheral immune function, which can alleviate the inflammatory response in the central nervous system and improve the prognosis of acute cerebral ischemic injury. Therefore, cAMP may play key roles in reducing post-stroke neuroinflammatory damage. The protective roles of the cAMP indicate that the cAMP enhancing drugs such as cAMP supplements, phosphodiesterase inhibitors, adenylate cyclase agonists, which are currently used in the treatment of heart and lung diseases. They are potentially able to be applied as a new therapeutic strategy in ischemic stroke. This review focuses on the immune-regulating roles and the clinical implication of cAMP in acute ischemic stroke.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Monofosfato de Adenosina , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Células Endoteliais , Humanos , Acidente Vascular Cerebral/tratamento farmacológico
12.
J Alzheimers Dis ; 73(2): 503-515, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31796671

RESUMO

Inflammation resolution is regulated by specialized pro-resolving lipid mediators (SPMs) and the levels of SPMs are found decreased in Alzheimer's disease (AD) brain. We have previously found that one of the SPMs, Maresin1 (MaR1), improved neuronal survival and increase microglial phagocytosis of amyloid-ß 1-42 (Aß42); however, the mechanisms underlying the protective mechanism remain further investigation. We aim to investigate the effects of MaR1 on microglial chemotaxis and activation in this study. Both indirect and direct primary neuron and microglia co-culture system was used in this study. Our results showed MaR1 downregulated the increased microglial chemotaxis induced by Aß42. The microglial inactivation marker CD200R was downregulated by Aß42 and upregulated by MaR1. Pro-inflammatory cytokines secretion such as tumor necrosis factor (TNF)-α were increased by Aß42 and these changes were revised by MaR1 treatment. In addition, the levels of chemokine monocyte chemoattractant protein (MCP)-1 were increased while the levels of anti-inflammatory factor IL-10 secretion were decreased by Aß42, and these changes were abolished by MaR1 treatment. Moreover, by proteomics analysis, we identified cell signaling pathways affected by MaR1 were not only limited to inflammation-related pathways such as P38, but also in pathways involved in cell survival, autophagy, axon formation, and apoptosis, including PI3K/AKT, mTOR, ERK, caspase3, Cdc42, and p75NTR. In conclusion, MaR1 promoted inflammation resolution by inhibiting chemotaxis and regulating activation of microglia. MaR1 played a neuroprotective role by affecting cell signaling pathways involving inflammation, cell survival, autophagy, axon formation, and apoptosis inhibition.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Ácidos Docosa-Hexaenoicos/farmacologia , Inflamação/tratamento farmacológico , Inflamação/patologia , Microglia/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Animais , Autofagia/efeitos dos fármacos , Axônios/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quimiotaxia/efeitos dos fármacos , Técnicas de Cocultura , Citocinas/biossíntese , Inflamação/induzido quimicamente , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Receptores Imunológicos/biossíntese , Receptores Imunológicos/genética , Transdução de Sinais/efeitos dos fármacos
13.
Curr Mol Med ; 19(10): 739-745, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31453784

RESUMO

BACKGROUND: Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against the acetylcholine receptors (AChR) of the skeletal muscles. An imbalance in various T helper (Th) cells, including Th1, Th2, Th17, Th22 and follicular helper T (TFH) cells, has been found associated with immunological disturbances. OBJECTIVE: In this study, we aim to investigate the role of the Th cells in peripheral blood of MG patients. MATERIALS AND METHODS: A total of 33 MG patients and 34 age matched controls were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque density gradient centrifugation assay. The proportion of TFH cells in PBMC were analyzed using flow-cytometry assay by determining the levels of cellular markers CD4, CXCR5, CD45RO, CD45RA and ICOS and PD-1. The levels of IFN-γ, IL-4, IL-17 and IL-21 in serum were analyzed by Cytometric Bead Array. The serum IL-22 level was analyzed by ELISA. RESULTS: The frequency of TFH cells in PBMCs was higher than those in healthy subjects and correlated to the severity of MG patients. The levels of pro-inflammatory cytokines IFN-γ, IL-17 and IL-21 were elevated in the serum of MG patients, while there were no significant differences regarding the levels of IL-4 and IL-22 between MG patients and control subjects. CONCLUSION: Our findings suggest that Th cells and their cytokines balance of MG patients are involved in the clinical condition or severity of MG disease.


Assuntos
Citocinas/sangue , Mediadores da Inflamação/sangue , Leucócitos Mononucleares/metabolismo , Miastenia Gravis/patologia , Linfócitos T Auxiliares-Indutores/metabolismo , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/sangue , Miastenia Gravis/imunologia , Adulto Jovem
14.
J Plant Physiol ; 240: 152991, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31207459

RESUMO

The coding sequence of NtabSPL6-1 was cloned by high-fidelity PCR with specific primers and was used in construction of a binary vector for overexpression. Wild-type Col-0 Arabidopsis plants and Qinyan95 tobacco leaves were transformed using floral dip and leaf disc methods, respectively. Phenotypic observation showed that constitutive expression of NtabSPL6-1 in Arabidopsis could promote the development of trichomes on leaf epidermis and influence the growth pattern of cauline leaves. In tobacco, ectopic expression of NtabSPL6-1 led to dwarfism of the plants and alteration of the leaf structure, accompanied by changes of the glandular trichomes in development. At the same time, the self-regulation capability of NtabSPL6-1 was determined by yeast two-hybrid system. The results indicated that SBP-C terminal domain and C terminal domain of NtabSPL6-1 possessed strong transcriptional activation ability; the intact protein, N terminal domain, and the first peptide fragment in N terminal domain possessed weak transcriptional activation ability; and the second and the third peptide fragments in N terminal domain had no transcriptional activation ability, suggesting the N terminal domain of NtabSPL6-1 could block the activity of the C terminal domain. NtabSPL6-1 may affect the resistance of plants to biotic stress factors indirectly by regulation of the trichome growth.


Assuntos
Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Nicotiana/genética , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Nicotiana/crescimento & desenvolvimento , Nicotiana/metabolismo , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/crescimento & desenvolvimento
17.
Mol Neurobiol ; 56(8): 5586-5607, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30652267

RESUMO

Protein kinase A (PKA) is a ser/thr kinase that is critical for maintaining essential neuronal functions including mitochondrial homeostasis, bioenergetics, neuronal development, and neurotransmission. The endogenous pool of PKA is targeted to the mitochondrion by forming a complex with the mitochondrial scaffold A-kinase anchoring protein 121 (AKAP121). Enhanced PKA signaling via AKAP121 leads to PKA-mediated phosphorylation of the fission modulator Drp1, leading to enhanced mitochondrial networks and thereby blocking apoptosis against different toxic insults. In this study, we show for the first time that AKAP121/PKA confers neuroprotection in an in vitro model of oxidative stress induced by exposure to excess glutamate. Unexpectedly, treating mouse hippocampal progenitor neuronal HT22 cells with an acute dose or chronic exposure of glutamate robustly elevates PKA signaling, a beneficial compensatory response that is phenocopied in HT22 cells conditioned to thrive in the presence of excess glutamate but not in parental HT22 cells. Secondly, redirecting the endogenous pool of PKA by transiently transfecting AKAP121 or transfecting a constitutively active mutant of PKA targeted to the mitochondrion (OMM-PKA) or of an isoform of AKAP121 that lacks the KH and Tudor domains (S-AKAP84) are sufficient to significantly block cell death induced by glutamate toxicity but not in an oxygen deprivation/reperfusion model. Conversely, transient transfection of HT22 neuronal cells with a PKA-binding-deficient mutant of AKAP121 is unable to protect against oxidative stress induced by glutamate toxicity suggesting that the catalytic activity of PKA is required for AKAP121's protective effects. Mechanistically, AKAP121 promotes neuroprotection by enhancing PKA-mediated phosphorylation of Drp1 to increase mitochondrial fusion, elevates ATP levels, and elicits an increase in the levels of antioxidants GSH and superoxide dismutase 2 leading to a reduction in the level of mitochondrial superoxide. Overall, our data supports AKAP121/PKA as a new molecular target that confers neuroprotection against glutamate toxicity by phosphorylating Drp1, to stabilize mitochondrial networks and mitochondrial function and to elicit antioxidant responses.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ácido Glutâmico/toxicidade , Mitocôndrias/metabolismo , Neuroproteção , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , Dinaminas/metabolismo , Glutationa/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Modelos Biológicos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Neuroproteção/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Superóxido Dismutase/metabolismo
18.
Medicine (Baltimore) ; 97(40): e12576, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30290619

RESUMO

Facial nerve paralysis is a common complication following cerebellopontine angle (CPA) surgery. This study investigated the prognostic value of facial nerve motor-evoked potentials (FNMEPs) elicited by transcranial electrical stimulation for facial nerve outcome after CPA tumorectomy.A total of 95 patients were enrolled in this study between January 2014 and January 2016. All these patients underwent CPA tumorectomy (unilateral, n = 95; bilateral, n = 1). Intraoperative FNMEP elicited by transcranial electrical stimulation was recorded. The short- and long-term postoperative facial nerve functions were evaluated according to the House-Brackmann (HB) scale. The correlation between perioperative changes in the FNMEP stimulus threshold (delta FNMEP = postoperative stimulus threshold level-preoperative stimulus threshold level) and postoperative facial nerve functions were analyzed.On the first day postoperatively, the facial nerve function was HB grade I in 67, grade II in 17, grade III in 7, and grade IV in 5 facial nerves. One year postoperatively, the facial nerve function was grade I in 80, grade II in 11, grade III in 3, and grade IV in 2 facial nerves. The delta FNMEP was significantly correlated with the short- and long-term facial nerve function; receiver operating characteristic (ROC) curves yielded a cut-off delta FNMEP value of 30 V (sensitivity, 91.3%; specificity, 98.6%) and 75 V (sensitivity, 100%; specificity, 98.8%) for predicting short- and long-term facial nerve function damage, respectively.FNMEP elicited by transcranial electrical stimulation is an effective and safe approach for predicting facial nerve function in CPA tumorectomy. A high delta FNMEP is a potential indicator for the prediction of postoperative facial nerve damage.


Assuntos
Neoplasias Cerebelares/cirurgia , Ângulo Cerebelopontino/cirurgia , Nervo Facial/fisiopatologia , Paralisia Facial/etiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Potencial Evocado Motor , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
19.
J Neuroinflammation ; 15(1): 198, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-29976213

RESUMO

BACKGROUND: Stroke is the second leading cause of death worldwide and the most common cause of adult-acquired disability in many nations. Thus, attenuating the damage after ischemic injury and improving patient prognosis are of great importance. We have indicated that ischemic preconditioning (IP) can effectively reduce the damage of ischemia reperfusion and that inhibition of gap junctions may further reduce this damage. Although we confirmed that the function of gap junctions is closely associated with glutamate, we did not investigate the mechanism. In the present study, we aimed to clarify whether the blockade of cellular communication at gap junctions leads to significant reductions in the levels of glutamate released by astrocytes following cerebral ischemia. METHODS: To explore this hypothesis, we utilized the specific blocking agent carbenoxolone (CBX) to inhibit the opening and internalization of connexin 43 channels in an in vitro model of oxygen-glucose deprivation/re-oxygenation (OGD/R), following IP. RESULTS: OGD/R resulted in extensive astrocytic glutamate release following upregulation of hemichannel activity, thus increasing reactive oxygen species (ROS) generation and subsequent cell death. However, we observed significant increases in neuronal survival in neuron-astrocyte co-cultures that were subjected to IP prior to OGD/R. Moreover, the addition of CBX enhanced the protective effects of IP during the re-oxygenation period following OGD, by means of blocking the release of glutamate, increasing the level of the excitatory amino acid transporter 1, and downregulating glutamine expression. CONCLUSIONS: Our results suggest that combined use of IP and CBX represents a novel therapeutic strategy to attenuate damage from cerebral ischemia with minimal adverse side effects.


Assuntos
Carbenoxolona/farmacologia , Junções Comunicantes/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Oxigênio/metabolismo , Oxigênio/farmacologia , Sistema X-AG de Transporte de Aminoácidos/genética , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Animais Recém-Nascidos , Antígeno CD11b/metabolismo , Células Cultivadas , Córtex Cerebral/citologia , Técnicas de Cocultura , Embrião de Mamíferos , Junções Comunicantes/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Interleucina-1beta/metabolismo , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
20.
Expert Opin Ther Targets ; 21(1): 103-112, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27817222

RESUMO

INTRODUCTION: Guillain-Barré syndrome (GBS) is an immune-mediated disorder in the peripheral nervous system (PNS), and experimental autoimmune neuritis (EAN) serves as an animal model of GBS. TNF-α plays an important role in the pathogenesis of GBS and is a potential therapeutic target of GBS. Areas covered: 'TNF-α' and 'Guillain-Barré syndrome' were the keywords used to search for related publications on Pubmed. By binding to different TNF receptors, TNF-α bears distinct immune properties. TNF-α gene polymorphisms are associated with the features of GBS. The major role of TNF-α in GBS/EAN is to aggravate inflammation; however, data from several studies indicated a protective role of TNF-α. Multiple lines of evidence point to TNF-α as a potential therapeutic target for GBS. However, such clinical trials are scarce in that GBS per se is a probable side effect of anti-TNF-α treatment. Expert opinion: TNF-α plays a dual role in GBS and EAN, and is a potential therapeutic target on GBS/EAN.


Assuntos
Síndrome de Guillain-Barré/tratamento farmacológico , Terapia de Alvo Molecular , Fator de Necrose Tumoral alfa/metabolismo , Animais , Modelos Animais de Doenças , Síndrome de Guillain-Barré/fisiopatologia , Humanos , Inflamação/patologia , Neurite Autoimune Experimental/tratamento farmacológico , Neurite Autoimune Experimental/fisiopatologia , Polimorfismo Genético , Fator de Necrose Tumoral alfa/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA