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1.
Can J Neurol Sci ; 39(3): 347-51, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22547516

RESUMO

OBJECTIVE: Conus medullaris syndrome (CMS) is a clinical neurologic syndrome caused by a conus medullaris lesion. CMS is a heterogeneous entity with various etiologies such as trauma or a space-occupying lesion. Multiple cases of CMS following spinal anesthesia have been reported, but CMS after radioisotope (RI) cisternography has not yet been reported. METHODS: We present four patients who developed CMS after RI cisternography. RESULTS: All experienced neurological deficits such as paraparesis, sensory loss, and urinary incontinence three to four days after RI cisternography. Two showed abnormalities on lumbar magnetic resonance imaging, and three had complete symptom resolution within ten weeks. CONCLUSIONS: The pathomechanism of the CMS is unclear, but we hypothesize that RI neurotoxicity might be responsible. It is possible that the use of low-dose 99mTc-DTPA or an alternative diagnostic tool such as magnetic resonance cisternography could help to prevent this complication.


Assuntos
Angiografia Cintilográfica/efeitos adversos , Compressão da Medula Espinal/etiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Radiografia , Medula Espinal/diagnóstico por imagem
2.
Mol Neurobiol ; 53(1): 695-705, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25577170

RESUMO

Although statins, or hydroxymethylglutaryl coenzyme A (HMG-Co A) reductase inhibitors, are generally used to decrease levels of circulating cholesterol, they have also been reported to have neuroprotective effects through various mechanisms. However, recent results have indicated that they may be harmful in patients with amyotrophic lateral sclerosis (ALS). In this study, we investigate whether atorvastatin protects motor neuron-like cells (NSC-34D) from oxidative stress. To evaluate the effects of atorvastatin or hydrogen peroxide or both on NSC-34D cells, the cells were treated with various combinations of these agents. To evaluate the viability of the cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and trypan blue staining were performed. Levels of free radicals and intracellular signaling proteins were evaluated using the fluorescent probe 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and Western blotting, respectively. Atorvastatin protected NSC-34D cells against oxidative stress in a concentration-dependent manner. This neuroprotective effect of atorvastatin was blocked by LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor and by FR180204, a selective extracellular signal-related kinase (ERK) inhibitor. Atorvastatin treatment increased the expression levels of p85αPI3K, phosphorylated Akt, phosphorylated glycogen synthase kinase-3ß, phosphorylated ERK, and Bcl-2, which are proteins related to survival. Furthermore, atorvastatin decreased the levels of cytosolic cytochrome C, Bax, cleaved caspase-9, and cleaved caspase-3, which are associated with death in oxidative stress-injured NSC-34D cells. We conclude that atorvastatin has a protective effect against oxidative stress in motor neurons by activating the PI3K and ERK pathways as well as by scavenging free radicals. These findings indicate that statins could help protect motor neurons from oxidative stress.


Assuntos
Atorvastatina/farmacologia , Sequestradores de Radicais Livres/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Neurônios Motores/metabolismo , Estresse Oxidativo/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Antioxidantes/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Radicais Livres/antagonistas & inibidores , Radicais Livres/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Neurônios Motores/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos
3.
Brain Res Mol Brain Res ; 133(2): 176-86, 2005 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-15710234

RESUMO

The effects of diallyl disulfide (DADS), a garlic-derived compound, on the viability of neuronal cells and cell signals, including phosphatidylinositol 3-kinase (PI3K)/Akt, glycogen synthase kinase-3 (GSK-3), cytochrome c, caspase-3, and poly(ADP-ribose) polymerase (PARP), were investigated in PC12 cells neuronally differentiated by nerve growth factor. To evaluate the toxicity of DADS itself, nPC12 cells were treated with several concentrations of DADS, and 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue stain revealed that the viability was not affected by low concentration of DADS, up to 20 microM, but it was decreased at higher than this concentration. The levels of free radicals and membrane lipid peroxidation were significantly increased in nPC12 cells when treated with more than 50 microM DADS, and treatment of PC12 cells with 100 microM DADS killed the cells by inhibiting PI3K/Akt and by promoting activation of GSK-3 and caspase-3, release of cytochrome c, and cleavage of PARP. To evaluate the protective effects of low concentration of DADS on oxidative stress-injured nPC12 cells, the viability of the cells (pretreated with DADS for 2 h vs. not pretreated) was evaluated 24 h after exposure to 100 microM H2O2 for 30 min. Compared to the cells treated with 100 microM H2O2 only, pretreatment of the cells with 20 microM DADS before exposure to 100 microM H2O2 increased the viability and induced activation of PI3K and Akt, inactivation of GSK-3, and inhibition of cytochrome c release, caspase-3 activation, and PARP cleavage. These results indicate that low concentration of DADS has neuroprotective effects by activating PI3K/Akt and by inhibiting GSK-3 activation, cytochrome c release, caspase-3 activation, and PARP cleavage, whereas high concentration is rather cytotoxic. Therefore, some specific optimum concentration of DADS may be a new potential therapeutic strategy for oxidative stress injured in vitro model of neurodegenerative diseases.


Assuntos
Compostos Alílicos/farmacologia , Apoptose/efeitos dos fármacos , Dissulfetos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Células PC12/efeitos dos fármacos , Animais , Anti-Hipertensivos/farmacologia , Western Blotting/métodos , Caspase 3 , Caspases/metabolismo , Contagem de Células/métodos , Diferenciação Celular , Sobrevivência Celular/efeitos dos fármacos , Cromonas/farmacologia , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Fluoresceínas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/metabolismo , Peróxido de Hidrogênio/toxicidade , Indóis , Glicoproteínas de Membrana/metabolismo , Morfolinas/farmacologia , Neurônios/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Células PC12/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Sais de Tetrazólio , Tiazóis , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Azul Tripano
4.
Amyloid ; 12(1): 62-4, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16076613

RESUMO

A 39-year-old man with progressive peripheral neuropathy and autonomic failure showed amyloid deposition on sural nerve biopsy. Direct DNA sequencing of the TTR gene revealed a G to T mutation, causing a Lys to Asn substitution at position 35. This is the first FAP case in Korea which was diagnosed by a DNA test.


Assuntos
Neuropatias Amiloides Familiares/genética , Amiloide/genética , Mutação/genética , Pré-Albumina/genética , Adolescente , Adulto , Idade de Início , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
5.
Brain Res Mol Brain Res ; 118(1-2): 72-81, 2003 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-14559356

RESUMO

The effects of epigallocatechin gallate (EGCG) on the phosphoinositide 3-kinase (PI3K)/Akt and glycogen synthase kinase-3 (GSK-3) pathway during oxidative-stress-induced injury were studied using H2O2-treated PC12 cells, which were differentiated by nerve growth factor (NGF). Following 100 microM H2O2 exposure, the viability of differentiated PC12 cells (EGCG or z-VAD-fmk pretreated vs. not pretreated) was evaluated the number of viable cell with Trypan blue and 3,4,5-dimethylthiazol-2-yl (MTT). Additionally, expression of cytochrome c, caspase-3, poly(ADP-ribose) polymerase (PARP), PI3K/Akt and GSK-3 was examined using Western blot analyses. EGCG or z-VAD-fmk-pretreated PC12 cells showed an increase of viability compared to untreated PC12 cells, and pretreatment of PC12 cells with either agent induced a dose-dependent inhibition of caspase-3 activation and PARP cleavage. However, inhibition of cytochrome c release was only detected in EGCG-pretreated cells. Upon examination of the PI3K/Akt and GSK-3 upstream pathway, Western blots of EGCG pretreated cells showed decreased immunoreactivity (IR) of Akt and GSK-3 and increased IR of p85a PI3K, phosphorylated Akt and phosphorylated GSK-3. In contrast, no changes were seen in z-VAD-fmk-pretreated cells. These results show that EGCG affects the PI3K/Akt, GSK-3 pathway as well as downstream signaling, including the cytochrome c and caspase-3 pathways. Therefore, it is suggested that EGCG-mediated activation of PI3K/Akt and inhibition of GSK-3 could be a new potential therapeutic strategy for neurodegenerative diseases associated with oxidative injury.


Assuntos
Apoptose/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/farmacologia , Doenças Neurodegenerativas/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Proteínas Serina-Treonina Quinases , Animais , Apoptose/fisiologia , Caspase 3 , Inibidores de Caspase , Caspases/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Citocromos c/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/metabolismo , Fator de Crescimento Neural/farmacologia , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/enzimologia , Estresse Oxidativo/fisiologia , Células PC12 , Fosfatidilinositol 3-Quinases/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases , Proteínas/metabolismo , Proteínas Proto-Oncogênicas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos
6.
Toxicology ; 202(3): 213-25, 2004 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-15337584

RESUMO

This study was undertaken to evaluate the effect of the G93A mutation in the human Cu/Zn-superoxide dismutase gene (hSOD1) on the phosphatidylinositol-3-kinase (PI3K)/Akt and glycogen synthase kinase-3 (GSK-3) pathway in motoneuron, and to determine the role of epigallocatechin gallate (EGCG) on oxidative stress-injured motoneurons. The viability of G93A mutant cells was less than that of wild-type cells, and the activation of PI3K and the phosphorylation of Akt and GSK-3 in G93A mutant cells decreased compared with wild-type hSOD1 4.1 cells. In the experiment to evaluate the effect of oxidative stress and/or EGCG on these motoneurons, after exposure to 400 microM H2O2, the MTT assay revealed greatly reduced viability of G93A mutant cells compared with wild-type cells, and pre-treatment of these cells with EGCG before H2O2 exposure increased the viability of both cell lines. Western blot analysis showed that the G93A mutation and oxidative stress decreased survival signals including PI3K/Akt but increased death signals including GSK-3; however, pre-treatment with EGCG increased survival signals but decreased death signals. These results suggest that PI3K/Akt and GSK-3 activities are altered in G93A mutant cells and EGCG-induced activation of PI3K/Akt and inhibition of GSK-3 could be a new potential therapeutic strategy for ALS associated with oxidative injury.


Assuntos
Apoptose/efeitos dos fármacos , Catequina/análogos & derivados , Catequina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Western Blotting , Linhagem Celular , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Neurônios Motores/enzimologia , Neurônios Motores/patologia , Mutação , Estresse Oxidativo/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Superóxido Dismutase/genética
7.
Neurotoxicology ; 25(5): 793-802, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15288510

RESUMO

Epigallocatechin gallate (EGCG) is one of most famous compounds of green tea. EGCG suppresses apoptosis induced by oxidative radical stress through several mechanisms. This study was designed to investigate whether EGCG plays a cytoprotective role by activating phosphatidylinositol-3 kinase (PI3K)/Akt-dependent anti-apoptotic pathway and inhibiting glycogen synthase kinase-3 (GSK-3) activity in oxidative stressed N18D3 neural cells. N18D3 cells, mouse neuroblastoma X dorsal root ganglion hybrid cell line, were pre-treated with EGCG or z-VAD-fmk, non-selective caspase inhibitor used as a control substance, for 2 h. The N18D3 cells were then exposed to low concentration of H(2)O(2) (100 microM) for 30 min, and further incubated for 24 h. MTT (3,[4,5-dimethylthiazol]-2-yl) assay and trypan blue staining were used to identify cell viability. Immunoreactivity (IR) of PI3K, Akt, and GSK-3 beta were measured by Western blotting. MTT assay and trypan blue staining showed that EGCG and z-VAD-fmk significantly increased cell viability, and IR of PI3K, phospho-Akt and phospho-GSK-3 beta was significantly increased in the cells treated with EGCG, but not in z-VAD-fmk treated. These results imply that EGCG has neuroprotective effect by increasing PI3K/Akt-dependent anti-apoptotic signals.


Assuntos
Catequina/análogos & derivados , Catequina/farmacologia , Quinase 3 da Glicogênio Sintase/fisiologia , Neurônios/fisiologia , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Oncogênicas de Retroviridae/fisiologia , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Inibidores de Caspase , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Peróxido de Hidrogênio/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Proteína Oncogênica v-akt , Oxidantes/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
8.
Brain Res ; 1551: 1-12, 2014 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-24440775

RESUMO

Hypertension is associated with oxidative stress. Amlodipine besylate (AB) and benidipine hydrochloride (BH), which are Ca(2+) antagonists, have been reported to reduce oxidative stress. In this study, we examined the neuroprotective effects of AB and BH on oxidative stress-injured neural stem cells (NSCs), with a focus on the phosphatidylinositol 3-kinase (PI3K) pathway and the extracellular signal-regulated kinase (ERK) pathway. After treatment with H2O2, the viability of NSCs decreased in a concentration-dependent manner; however, co-treatment with AB or BH restored the viability of H2O2-injured NSCs. H2O2 increased free radical production and apoptosis in NSCs, whereas co-treatment with AB or BH attenuated these effects. To evaluate the effects of AB or BH on the H2O2-inhibited proliferation of NSCs, we performed BrdU labeling and colony formation assays and found that NSC proliferation decreased upon H2O2 treatment but that combined treatment with AB or BH restored this proliferation. Western blot analysis showed that AB and BH increased the expression of cell survival-related proteins that were linked with the PI3K and ERK pathways but decreased the expression of cell death-related proteins. To investigate whether the PI3K and ERK pathways were directly involved in the neuroprotective effects of AB and BH on H2O2-treated NSCs, NSCs were pretreated with the PI3K inhibitor, LY294002, or the ERK inhibitor, FR180204, which significantly blocked the effects of AB and BH. Together, our results suggest that AB and BH restore the H2O2-inhibited viability and proliferation of NSCs by inhibiting oxidative stress and by activating the PI3K and ERK pathways.


Assuntos
Anlodipino/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Células-Tronco Neurais/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Nifedipino/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Células-Tronco Neurais/metabolismo , Nifedipino/farmacologia , Fosfatidilinositol 3-Quinase/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
10.
Neurointervention ; 9(1): 53-5, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24644532

RESUMO

Tortuous arteries are common clinical observation. Although mild tortuosity is asymptomatic, severe tortuosity can lead to ischemic attack in several organs. With advances in imaging technology, an increasing number of tortuous vessels have been detected. The purpose of this report is to describe a case of acute cerebral infarction due to tortuous subclavian artery and to review the literature.

11.
J Mov Disord ; 6(1): 21-2, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-24868421

RESUMO

There were few cases of thrombocytopenia associated with levodopa. Herein, we report a patient with Parkinson's disease, who suffered thrombocytopenia related to long-term use of levodopa.

12.
Mol Neurobiol ; 47(2): 811-20, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23288365

RESUMO

Mesenchymal stromal cells (MSCs) are emerging as candidate cells for the treatment of neurological diseases because of their neural replacement, neuroprotective, and neurotrophic effects. However, the majority of MSCs transplanted by various routes fail to reach the site of injury, and they have demonstrated only minimal therapeutic benefit in clinical trials. Therefore, enhancing the migration of MSCs to target sites is essential for this therapeutic strategy to be effective. In this study, we assessed whether inhibition of glycogen synthase kinase-3ß (GSK-3ß) increases the migration capacity of MSCs during ex vivo expansion. Human bone marrow MSCs (hBM-MSCs) were cultured with various GSK-3ß inhibitors (LiCl, SB-415286, and AR-A014418). Using a migration assay kit, we found that the motility of hBM-MSCs was significantly enhanced by GSK-3ß inhibition. Western blot analysis revealed increased levels of migration-related signaling proteins such as phospho-GSK-3ß, ß-catenin, phospho-c-Raf, phospho-extracellular signal-regulated kinase (ERK), phospho-ß-PAK-interacting exchange factor (PIX), and CXC chemokine receptor 4 (CXCR4). In addition, real-time polymerase chain reaction demonstrated increased expression of matrix metalloproteinase-2 (MMP-2), membrane-type MMP-1 (MT1-MMP), and ß-PIX. In the reverse approach, treatment with ß-PIX shRNA or CXCR4 inhibitor (AMD 3100) reduced hBM-MSC migration. These findings suggest that inhibition of GSK-3ß during ex vivo expansion of hBM-MSCs may enhance their migration capacity by increasing expression of ß-catenin, phospho-c-Raf, phospho-ERK, and ß-PIX and the subsequent up-regulation of CXCR4. Enhancing the migration capacity of hBM-MSCs by treating these cells with GSK-3ß inhibitors may increase their therapeutic potential.


Assuntos
Movimento Celular/fisiologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/fisiologia , Células-Tronco Mesenquimais/citologia , Receptores CXCR4/biossíntese , Fatores de Troca de Nucleotídeo Guanina Rho/biossíntese , Regulação para Cima/fisiologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Glicogênio Sintase Quinase 3 beta , Humanos , Células-Tronco Mesenquimais/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Receptores CXCR4/fisiologia , Fatores de Troca de Nucleotídeo Guanina Rho/fisiologia , Regulação para Cima/efeitos dos fármacos
13.
Mol Neurobiol ; 47(2): 757-69, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23254998

RESUMO

Phosphatidylinositol 3-kinase (PI3K) plays several important roles in neuronal survival. Activation of the pathway is essential for the neuroprotective mechanisms of materials that shield neuronal cells from many stressful conditions. However, there have been no reports to date about the effect of the direct activation of the pathway in hypoxic injury of neuronal cells. We investigated whether the direct activation of the PI3K pathway inhibits neuronal cell death induced by hypoxia. Primary cultured cortical neurons (PCCNs) were exposed to hypoxic conditions (less than 1 mol% O2) and/or treated with PI3K activator. Hypoxia reduced the viability of PCCNs in a time-dependent manner, but treatment with PI3K significantly restored viability in a concentration-dependent manner. Among the signaling proteins involved in the PI3K pathway, those associated with survival, including Akt and glycogen synthase kinase-3ß, were decreased shortly after exposure to hypoxia and those associated with cell death, including BAX, apoptosis-induced factor, cytochrome c, caspase-9, caspase-3, and poly(ADP-ribose) polymerase (PARP), were increased. However, treatment with PI3K activator normalized the expression levels of those signaling proteins. PARP activity and levels of ATP and NAD(+) altered by hypoxia were also normalized with direct PI3K activation. All these findings suggest that direct and early activation is important for protecting neuronal cells from hypoxic injury.


Assuntos
Trifosfato de Adenosina/metabolismo , Córtex Cerebral/metabolismo , NAD/metabolismo , Neurônios/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Regulação para Cima/fisiologia , Animais , Hipóxia Celular/fisiologia , Células Cultivadas , Córtex Cerebral/patologia , Regulação para Baixo/fisiologia , Ativação Enzimática/fisiologia , Neurônios/patologia , Fosfatidilinositol 3-Quinase/fisiologia , Poli(ADP-Ribose) Polimerases/fisiologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia
14.
Stem Cells Dev ; 22(15): 2112-20, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23509892

RESUMO

Neurogenesis in the adult brain is important for memory and learning, and the alterations in neural stem cells (NSCs) may be an important part of Alzheimer's disease pathogenesis. The phosphatidylinositol 3-kinase (PI3K) pathway has been suggested to play an important role in neuronal cell survival and is highly involved in adult neurogenesis. Recently, coenzyme Q10 (CoQ10) was found to affect the PI3K pathway. We investigated whether CoQ10 could restore amyloid ß (Aß)25-35 oligomer-inhibited proliferation of NSCs by focusing on the PI3K pathway. To evaluate the effects of CoQ10 on Aß25-35 oligomer-inhibited proliferation of NSCs, NSCs were treated with several concentrations of CoQ10 and/or Aß25-35 oligomers. BrdU labeling, Colony Formation Assays, and immunoreactivity of Ki-67, a marker of proliferative activity, showed that NSC proliferation decreased with Aß25-35 oligomer treatment, but combined treatment with CoQ10 restored it. Western blotting showed that CoQ10 treatment increased the expression levels of p85α PI3K, phosphorylated Akt (Ser473), phosphorylated glycogen synthase kinase-3ß (Ser9), and heat shock transcription factor, which are proteins related to the PI3K pathway in Aß25-35 oligomers-treated NSCs. To confirm a direct role for the PI3K pathway in CoQ10-induced restoration of proliferation of NSCs inhibited by Aß25-35 oligomers, NSCs were pretreated with a PI3K inhibitor, LY294002; the effects of CoQ10 on the proliferation of NSCs inhibited by Aß25-35 oligomers were almost completely blocked. Together, these results suggest that CoQ10 restores Aß25-35 oligomer-inhibited proliferation of NSCs by activating the PI3K pathway.


Assuntos
Peptídeos beta-Amiloides/fisiologia , Proliferação de Células/efeitos dos fármacos , Células-Tronco Neurais/fisiologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Ubiquinona/análogos & derivados , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/farmacologia , Animais , Sobrevivência Celular , Células Cultivadas , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese , Fragmentos de Peptídeos/farmacologia , Ratos Sprague-Dawley , Transdução de Sinais , Ubiquinona/farmacologia
15.
Neurochem Int ; 61(7): 1172-82, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22944602

RESUMO

Cilnidipine, a calcium channel blocker, has been reported to have neuroprotective effects. We investigated whether cilnidipine could protect neurons from hypoxia and explored the role of the phosphatidylinositol 3-kinase (PI3K) and extracellular signal-related kinase (ERK) pathways in the neuroprotective effect of cilnidipine. The viability of a primary culture of cortical neurons injured by hypoxia, measured by trypan blue staining and lactate dehydrogenase (LDH) assay, was dramatically restored by cilnidipine treatment. TUNEL and DAPI staining showed that cilnidipine significantly reduced apoptotic cell death induced by hypoxia. Free radical stress and calcium influx induced by hypoxia were markedly decreased by treatment with cilnidipine. Survival signaling proteins associated with the PI3K and ERK pathways were significantly increased while death signaling proteins were markedly decreased in the primary culture of cortical neurons simultaneously exposed to cilnidipine and hypoxia when compared with the neurons exposed only to hypoxia. These neuroprotective effects of cilnidipine were blocked by treatment with a PI3K inhibitor or an ERK inhibitor. These results show that cilnidipine protects primary cultured cortical neurons from hypoxia by reducing free radical stress, calcium influx, and death-related signaling proteins and by increasing survival-related proteins associated with the PI3K and ERK pathways, and that activation of those pathways plays an important role in the neuroprotective effects of cilnidipine against hypoxia. These findings suggest that cilnidipine has neuroprotective effects against hypoxia through various mechanisms, as well as a blood pressure-lowering effect, which might help to prevent ischemic stroke and reduce neuronal injury caused by ischemic stroke.


Assuntos
Hipóxia Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Di-Hidropiridinas/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fármacos Neuroprotetores/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Cálcio/metabolismo , Células Cultivadas , Córtex Cerebral/citologia , Marcação In Situ das Extremidades Cortadas , Ratos , Ratos Sprague-Dawley
16.
Neurotoxicology ; 33(1): 85-90, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22186599

RESUMO

Oxidative stress plays critical roles in the pathogenic mechanisms of several neurodegenerative disorders including Alzheimer's disease (AD), thus much research effort has focused on antioxidants as potential treatment agents for AD. Coenzyme Q10 (CoQ10) is known to have powerful antioxidant effects. We investigated the neuroprotective effects of CoQ10 against Amyloid beta(25-35) (Aß(25-35))-induced neurotoxicity in rat cortical neurons. To evaluate the neuroprotective effects of CoQ10 on Aß(25-35)-injured neurons, primary cultured cortical neurons were treated with several concentrations of CoQ10 and/or Aß(25-35) for 48h. CoQ10 protected neuronal cells against Aß(25-35)-induced neurotoxicity in a concentration-dependent manner. These neuroprotective effects of CoQ10 were blocked by LY294002 (10µM), a phosphatidylinositol 3-kinase (PI3K) inhibitor. Aß(25-35) concentration-dependent increased free radical levels in rat cortical neurons, while combined treatment with CoQ10 reduced these free radical levels in a dose-dependent manner. Meanwhile, CoQ10 treatment of Aß(25-35)-injured primary cultured cortical neurons increased the expression levels of p85aPI3K, phosphorylated Akt, phosphorylated glycogen synthase kinase-3ß, and heat shock transcription factor, which are proteins related to neuronal cell survival, and decreased the levels of cytosolic cytochrome c and cleaved caspase-3, which are associated with neuronal cell death. Together, these results suggest that the neuroprotective effects of CoQ10 on Aß(25-35) neurotoxicity are mediated by inhibition of oxidative stress together with activation of the PI3-K/Akt pathway.


Assuntos
Peptídeos beta-Amiloides/farmacologia , Neurônios/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ubiquinona/análogos & derivados , Vitaminas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Citocromos c/metabolismo , Proteínas de Ligação a DNA , Relação Dose-Resposta a Droga , Interações Medicamentosas , Embrião de Mamíferos , Inibidores Enzimáticos/farmacologia , Radicais Livres/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase , Fatores de Transcrição de Choque Térmico , Marcação In Situ das Extremidades Cortadas/métodos , Indóis , Fosforilação , Ratos , Ratos Sprague-Dawley , Fatores de Transcrição , Ubiquinona/farmacologia
17.
Brain Res ; 1478: 64-73, 2012 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-23046589

RESUMO

Recanalization and secondary prevention are the main therapeutic strategies for acute ischemic stroke. Neuroprotective therapies have also been investigated despite unsuccessful clinical results. Coenzyme Q10 (CoQ10), which is an essential cofactor for electron transport in mitochondria, is known to have an antioxidant effect. We investigated the protective effects of CoQ10 against hypoxia in neural stem cells (NSCs). We measured cell viability and levels of intracellular signaling proteins after treatment with several concentrations of CoQ10 under hypoxia-reperfusion. CoQ10 protected NSCs against hypoxia-reperfusion in a concentration-dependent manner by reducing growth inhibition and inhibiting free radical formation. It increased the expression of a number of survival-related proteins such as phosphorylated Akt (pAkt), phosphorylated glycogen synthase kinase 3-ß (pGSK3-ß), and B-cell lymphoma 2 (Bcl-2) in NSCs injured by hypoxia-reperfusion and reduced the expression of death-related proteins such as cleaved caspase-3. We conclude that CoQ10 has effects against hypoxia-reperfusion induced damage to NSCs by enhancing survival signals and decreasing death signals.


Assuntos
Antioxidantes/farmacologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ubiquinona/análogos & derivados , Animais , Western Blotting , Hipóxia Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Radicais Livres/metabolismo , Marcação In Situ das Extremidades Cortadas , Células-Tronco Neurais/citologia , Ratos , Traumatismo por Reperfusão/metabolismo , Ubiquinona/farmacologia
18.
Neurotoxicology ; 32(6): 879-87, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21683736

RESUMO

The neurotoxicity of L-3,4-dihydroxyphenylalanine (L-DOPA), one of the most important drugs for the treatment of Parkinson's disease, still remains controversial, although much more data on L-DOPA neurotoxicity have been presented. Considering the well known neuroprotective effects of erythropoietin (EPO), the inhibitory effects of EPO on L-DOPA neurotoxicity need to be evaluated. Neuronally differentiated PC12 (nPC12) cells were treated with different concentrations of L-DOPA and/or EPO for 24h. Cell viability was evaluated using trypan blue, 4',6-diamidino-2-phenylindole (DAPI) and TUNEL staining, and cell counting. Free radicals and intracellular signaling protein levels were measured with 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and Western blotting, respectively. L-DOPA reduced nPC12 cell viability at higher concentrations, but combined treatment with EPO and L-DOPA significantly restored cell viability. Free radicals and hydroxyl radical levels increased by L-DOPA were decreased after combined treatment of L-DOPA and EPO. Levels of survival-related intracellular signaling proteins decreased in nPC12 cells treated with 200 µM L-DOPA but increased significantly in cells treated with 200µM L-DOPA and 5 µM EPO. However, cleaved caspase-3, a death-related protein, increased in nPC12 cells treated with 200 µM L-DOPA but decreased significantly in cells treated with 200 µM L-DOPA and 5 µM EPO. Pretreatment with LY294002, a phosphatidylinositol 3-kinase inhibitor, prior to combined treatment with EPO and L-DOPA almost completely blocked the protective effects of EPO. These results indicate that EPO can prevent L-DOPA neurotoxicity by activating the PI3K pathway as well as reducing oxidative stress.


Assuntos
Eritropoetina/farmacologia , Levodopa/toxicidade , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Animais , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Citoproteção , Relação Dose-Resposta a Droga , Humanos , Radical Hidroxila/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Ratos , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
20.
Eur J Neurosci ; 20(6): 1461-72, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15355313

RESUMO

Poly(ADP-ribose) polymerase (PARP) plays an important role in ischaemic cell death, and 3-aminobenzamide (3-AB), one of the PARP inhibitors, has a protective effect on ischaemic stroke. We investigated the neuroprotective mechanisms of 3-AB in ischaemic stroke. The occlusion of middle cerebral artery (MCA) was made in 170 Sprague-Dawley rats, and reperfusion was performed 2 h after the occlusion. Another 10 Sprague-Dawley rats were used for sham operation. 3-AB was administered to 85 rats 10 min before the occlusion [3-AB group (n = 85) vs. control group without 3-AB (n = 85)]. Infarct volume and water content were measured, brain magnetic resonance imaging, terminal deoxynucleotidyltransferase (TdT)-mediated dUTP-biotin nick end-labelling (TUNEL) and Cresyl violet staining were performed, and immunoreactivities (IRs) of poly(ADP-ribose) polymer (PAR), cleaved caspase-3, CD11b, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2), phospho-Akt (pAkt) and phospho-glycogen synthase kinase-3 (pGSK-3) were compared in the peri-infarcted region of the 3-AB group and its corresponding ischaemic region of the control group at 2, 8, 24 and 72 h after the occlusion. In the 3-AB group, the infarct volume and the water content were decreased (about 45% and 3.6%, respectively, at 24 h), the number of TUNEL-positive cells was decreased (about 36% at 24 h), and the IRs of PAR, cleaved caspase-3, CD11b, ICAM-1 and COX-2 were significantly reduced, while the IRs of pAkt and pGSK-3 were increased. These results suggest that 3-AB treatment could reduce the infarct volume by reducing ischaemic cell death, its related inflammation and increasing survival signals. The inhibition of PARP could be another potential neuroprotective strategy in ischaemic stroke.


Assuntos
Benzamidas/farmacologia , Isquemia Encefálica/patologia , Morte Celular , Epoprostenol/análogos & derivados , Fármacos Neuroprotetores/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases , Animais , Benzamidas/uso terapêutico , Western Blotting/métodos , Encéfalo/metabolismo , Encéfalo/patologia , Edema Encefálico/etiologia , Edema Encefálico/patologia , Edema Encefálico/prevenção & controle , Infarto Encefálico/etiologia , Infarto Encefálico/patologia , Infarto Encefálico/prevenção & controle , Isquemia Encefálica/etiologia , Isquemia Encefálica/metabolismo , Antígeno CD11b/metabolismo , Caspase 3 , Caspases/metabolismo , Contagem de Células/métodos , Morte Celular/efeitos dos fármacos , Ciclo-Oxigenase 2 , Feminino , Lateralidade Funcional/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Imuno-Histoquímica/métodos , Marcação In Situ das Extremidades Cortadas , Infarto da Artéria Cerebral Média/complicações , Inflamação/etiologia , Inflamação/prevenção & controle , Molécula 1 de Adesão Intercelular/metabolismo , Isoenzimas/metabolismo , Imageamento por Ressonância Magnética/métodos , Masculino , Fármacos Neuroprotetores/uso terapêutico , Poli(ADP-Ribose) Polimerases/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Sprague-Dawley , Coloração e Rotulagem , Fatores de Tempo
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