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1.
Cell ; 155(6): 1351-64, 2013 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-24290359

RESUMO

Parkinson's disease (PD) is characterized by loss of A9 dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). An association has been reported between PD and exposure to mitochondrial toxins, including environmental pesticides paraquat, maneb, and rotenone. Here, using a robust, patient-derived stem cell model of PD allowing comparison of A53T α-synuclein (α-syn) mutant cells and isogenic mutation-corrected controls, we identify mitochondrial toxin-induced perturbations in A53T α-syn A9 DA neurons (hNs). We report a pathway whereby basal and toxin-induced nitrosative/oxidative stress results in S-nitrosylation of transcription factor MEF2C in A53T hNs compared to corrected controls. This redox reaction inhibits the MEF2C-PGC1α transcriptional network, contributing to mitochondrial dysfunction and apoptotic cell death. Our data provide mechanistic insight into gene-environmental interaction (GxE) in the pathogenesis of PD. Furthermore, using small-molecule high-throughput screening, we identify the MEF2C-PGC1α pathway as a therapeutic target to combat PD.


Assuntos
Interação Gene-Ambiente , Mitocôndrias/efeitos dos fármacos , Paraquat/toxicidade , Doença de Parkinson/genética , Doença de Parkinson/patologia , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fatores de Transcrição MEF2 , Mutação/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo , Doença de Parkinson/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Espécies Reativas de Nitrogênio/metabolismo , Substância Negra/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
2.
Biochem Biophys Res Commun ; 701: 149583, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38330731

RESUMO

Endochondral ossification is a developmental process in the skeletal system and bone marrow of vertebrates. During endochondral ossification, primitive cartilaginous anlages derived from mesenchymal stem cells (MSCs) undergo vascular invasion and ossification. In vitro regeneration of endochondral ossification is beneficial for research on the skeletal system and bone marrow development as well as their clinical aspects. However, to achieve the regeneration of endochondral ossification, a stem cell-based artificial cartilage (cartilage organoid, Cart-Org) that possesses an endochondral ossification phenotype is required. Here, we modified a conventional 3D culture method to create stem cell-based Cart-Org by mixing it with a basement membrane extract (BME) and further characterized its chondrogenic and ossification properties. BME enlarged and matured the bone marrow MSC-based Cart-Orgs without any shape abnormalities. Histological analysis using Alcian blue staining showed that the production of cartilaginous extracellular matrices was enhanced in Cart-Org treated with BME. Transcriptome analysis using RNA sequencing revealed that BME altered the gene expression pattern of Cart-Org to a dominant chondrogenic state. BME triggered the activation of the SMAD pathway and inhibition of the NK-κB pathway, which resulted in the upregulation of SOX9, COL2A1, and ACAN in Cart-Org. BME also facilitated the upregulation of genes associated with hypertrophic chondrocytes (IHH, PTH1R, and COL10A1) and ossification (SP7, ALPL, and MMP13). Our findings indicate that BME promotes cartilaginous maturation and further ossification of bone marrow MSC-based Cart-Org, suggesting that Cart-Org treated with BME possesses the phenotype of endochondral ossification.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Animais , Osteogênese/genética , Medula Óssea , Membrana Basal , Cartilagem/metabolismo , Condrócitos/metabolismo , Fenótipo , Condrogênese/genética , Organoides , Diferenciação Celular
3.
J Biol Chem ; 298(5): 101833, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35304101

RESUMO

Bone marrow development and endochondral bone formation occur simultaneously. During endochondral ossification, periosteal vasculatures and stromal progenitors invade the primary avascular cartilaginous anlage, which induces primitive marrow development. We previously determined that bone marrow podoplanin (PDPN)-expressing stromal cells exist in the perivascular microenvironment and promote megakaryopoiesis and erythropoiesis. In this study, we aimed to examine the involvement of PDPN-expressing stromal cells in postnatal bone marrow generation. Using histological analysis, we observed that periosteum-derived PDPN-expressing stromal cells infiltrated the cartilaginous anlage of the postnatal epiphysis and populated on the primitive vasculature of secondary ossification center. Furthermore, immunophenotyping and cellular characteristic analyses indicated that the PDPN-expressing stromal cells constituted a subpopulation of the skeletal stem cell lineage. In vitro xenovascular model cocultured with human umbilical vein endothelial cells and PDPN-expressing skeletal stem cell progenies showed that PDPN-expressing stromal cells maintained vascular integrity via the release of angiogenic factors and vascular basement membrane-related extracellular matrices. We show that in this process, Notch signal activation committed the PDPN-expressing stromal cells into a dominant state with basement membrane-related extracellular matrices, especially type IV collagens. Our findings suggest that the PDPN-expressing stromal cells regulate the integrity of the primitive vasculatures in the epiphyseal nascent marrow. To the best of our knowledge, this is the first study to comprehensively examine how PDPN-expressing stromal cells contribute to marrow development and homeostasis.


Assuntos
Medula Óssea , Periósteo , Medula Óssea/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Periósteo/metabolismo , Células Estromais/metabolismo
4.
Thromb J ; 21(1): 10, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36698142

RESUMO

BACKGROUND: Tranexamic acid (TXA) is an antifibrinolytic drug that blocks lysine-binding sites on the profibrinolytic enzyme plasminogen. Aortic diseases with chronic consumption coagulopathy may lead to disseminated intravascular coagulation (DIC) and cause fatal bleeding. Although the use of antifibrinolytic agents in DIC is generally not recommended due to enhanced fibrin deposition risking thrombotic symptoms, the efficacy of TXA has been reported in several cases of DIC with aortic diseases. However, the efficacy and safety of TXA for bleeding symptoms of chronic consumption coagulopathy with aortic diseases have not been studied in detail. METHODS: We evaluated the efficacy of TXA in 14 patients with chronic consumptive coagulopathy due to aortic disease complicated by bleeding symptoms. Changes in coagulation and fibrinolysis parameters from baseline were analyzed with Wilcoxon matched-pairs signed-rank tests, excluding missing values. Kaplan-Meier curves were used to analyze overall survival. RESULTS: Median age was 78.5 years (range, 66-89 years) and median observation period was 448 days (range, 0-2282 days). Twelve patients had chronic renal failure and 1 patient had chronic liver failure. Before starting treatment, median Japanese Ministry of Health and Welfare DIC diagnostic criteria score was 8 (range, 4-11) and median platelet count was 64 × 109/L (range, 25-97 × 109/L). Twelve patients underwent evaluation of bleeding symptoms after introduction of TXA, and 10 of those 12 patients showed improved bleeding tendencies within 30 days (median, 5.0 days). One patient with chronic liver failure showed worsening of bleeding symptoms. Although only one patient was initiated TXA in combination with anticoagulants, no significant worsening of thrombotic events was observed within 30 days. CONCLUSIONS: TXA therapy appears effective against chronic consumptive coagulopathy with bleeding due to aortic disease, with few side effects.

5.
BMC Cardiovasc Disord ; 23(1): 140, 2023 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-36934235

RESUMO

BACKGROUND: It can be difficult to diagnose coronary artery disease in patients with acute coronary syndrome if coronary angiography does not identify stenosis. Coronary inflammation, which can contribute to the pathogenesis of coronary artery disease and acute coronary syndrome, can be quantified using the perivascular fat attenuation index. Furthermore, the perivascular fat attenuation index is a marker for all-cause mortality, cardiac-related mortality and impaired global coronary flow reserve. CASE PRESENTATION: Here we report a case of a patient presenting with symptoms of acute coronary syndrome. The patient had hypokinesis of the lateral-posterior wall of the left ventricle, decreased myocardial perfusion in the posterior wall myocardium and elevated myocardial troponin-T and creatine phosphokinase levels. However, coronary computed tomography angiography did not identify arterial stenosis. The patient did have an increased perivascular fat attenuation index, indicating coronary inflammation. Moreover, the fat attenuation index was higher around the left circumflex artery than around the right coronary artery or left anterior descending artery. Intravascular ultrasonography identified an intramural haematoma, leading to a diagnosis of type 3 spontaneous coronary artery dissection in the left circumflex artery. CONCLUSIONS: Perivascular fat attenuation index may be a useful tool to help identify and localise disease-causing lesions, and to direct further testing to confirm a diagnosis of spontaneous coronary artery dissection in acute coronary syndrome patients without significant arterial stenosis.


Assuntos
Síndrome Coronariana Aguda , Doença da Artéria Coronariana , Placa Aterosclerótica , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etiologia , Angiografia por Tomografia Computadorizada/métodos , Constrição Patológica , Placa Aterosclerótica/patologia , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Tecido Adiposo/diagnóstico por imagem , Isquemia , Inflamação , Valor Preditivo dos Testes
6.
Ann Hepatol ; 27(1): 100545, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34571264

RESUMO

INTRODUCTION AND OBJECTIVES: Hepatitis C virus (HCV) infections in patients with hemophilia lead to the development of hepatocellular carcinoma (HCC) at a relatively younger age than that in patients without hemophilia. Although recent progress in direct-acting-antivirals has facilitated a high rate of sustained virological response (SVR), the clinical influence of HCV eradication in hemophilia patients remains unclear. This study aimed to compare the clinical outcomes of SVR against HCV in patients with and without hemophilia. PATIENTS AND METHODS: The study enrolled 699 patients who achieved SVR after HCV antiviral treatment. Patients were divided into two groups: 78 patients with hemophilia (H group) and 621 patients without hemophilia (NH group). We evaluated patient characteristics, clinical outcomes, and the cumulative incidence of HCC after SVR. RESULTS: Compared with the NH group, patients in the H-group were significantly younger and had a lower hepatic fibrosis score. No difference was found in the incidence of liver-related disease or overall death between the two groups over a mean follow-up period of 7 years. Four patients in the H group and 36 patients in the NH group were diagnosed with HCC after SVR. Multivariate analysis showed that male sex, age, and cirrhosis were significant risk factors for HCC incidence. There was no significant difference in the cumulative incidence of HCC after propensity-score matching adjusting for the risk factors of HCC between the two groups. CONCLUSION: Hemophilia is not a significant risk factor for hepatocarcinogenesis after SVR against HCV.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Hemofilia A/complicações , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Adulto , Idoso , Antivirais/uso terapêutico , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/epidemiologia , Feminino , Seguimentos , Hepatite C/complicações , Hepatite C/epidemiologia , Humanos , Incidência , Japão/epidemiologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
7.
Haemophilia ; 27(1): 100-107, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33245832

RESUMO

Haemophilia is an X-linked inherited bleeding disorder caused by coagulation factor deficiency. Hepatocellular carcinoma (HCC) is a major complication associated with the disease. No study thus far has investigated the safety and efficacy of percutaneous radiofrequency ablation (RFA) for HCC in patients with haemophilia. AIM: This study aimed to evaluate the safety and efficacy of RFA for HCC in haemophilia patients. METHODS: From July 2008 to June 2019, 217 patients with HCC underwent 300 RFA sessions. Of these, 18 sessions were performed in ten haemophilia patients (H group) and 282 in 207 non-haemophilia patients (NH group). The patients' characteristics, incidence of haemorrhagic complications and rates of local tumour recurrence were compared between the groups. RESULTS: A majority of the haemophilia patients received clotting factor concentrate replacement therapy before and after RFA treatment, with the aim of reaching a plasma clotting factor level of higher than 60%-80%. Twelve haemorrhagic complications were observed in the NH group (4.2%; 12/282). Major bleeding requiring control procedures was observed in two patients and minor bleeding with careful observation was noted in ten patients. No bleeding complications were observed in the H group (0/18). There were no significant differences in the 5-year local tumour recurrence rates after RFA treatment between the groups (35.0% in the H group and 32.1% in the NH group). CONCLUSION: RFA could be an effective and a safe method for HCC treatment in patients with haemophilia.


Assuntos
Carcinoma Hepatocelular , Ablação por Cateter , Hemofilia A , Neoplasias Hepáticas , Ablação por Radiofrequência , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/cirurgia , Hemofilia A/complicações , Humanos , Neoplasias Hepáticas/complicações , Ablação por Radiofrequência/efeitos adversos , Estudos Retrospectivos , Resultado do Tratamento
8.
Proc Natl Acad Sci U S A ; 114(20): E4048-E4056, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28461502

RESUMO

Gaining mechanistic insight into interaction between causative factors of complex multifactorial diseases involving photoreceptor damage might aid in devising effective therapies. Oxidative stress is one of the potential unifying mechanisms for interplay between genetic and environmental factors that contribute to photoreceptor pathology. Interestingly, the transcription factor myocyte enhancer factor 2d (MEF2D) is known to be important in photoreceptor survival, as knockout of this transcription factor results in loss of photoreceptors in mice. Here, using a mild light-induced retinal degeneration model, we show that the diminished MEF2D transcriptional activity in Mef2d+/- retina is further reduced under photostimulation-induced oxidative stress. Reactive oxygen species cause an aberrant redox modification on MEF2D, consequently inhibiting transcription of its downstream target, nuclear factor (erythroid-derived 2)-like 2 (NRF2). NRF2 is a master regulator of phase II antiinflammatory and antioxidant gene expression. In the Mef2d heterozygous mouse retina, NRF2 is not up-regulated to a normal degree in the face of light-induced oxidative stress, contributing to accelerated photoreceptor cell death. Furthermore, to combat this injury, we found that activation of the endogenous NRF2 pathway using proelectrophilic drugs rescues photoreceptors from photo-induced oxidative stress and may therefore represent a viable treatment for oxidative stress-induced photoreceptor degeneration, which is thought to contribute to some forms of retinitis pigmentosa and age-related macular degeneration.


Assuntos
Fator 2 Relacionado a NF-E2/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Degeneração Retiniana/etiologia , Abietanos , Animais , Modelos Animais de Doenças , Haploinsuficiência , Luz/efeitos adversos , Fatores de Transcrição MEF2/genética , Camundongos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
9.
Neurobiol Dis ; 127: 390-397, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30928642

RESUMO

Tuberous sclerosis (TSC) is an autosomal dominant disorder caused by heterozygous mutations in the TSC1 or TSC2 gene. TSC is often associated with neurological, cognitive, and behavioral deficits. TSC patients also express co-morbidity with anxiety and mood disorders. The mechanism of pathogenesis in TSC is not entirely clear, but TSC-related neurological symptoms are accompanied by excessive glutamatergic activity and altered synaptic spine structures. To address whether extrasynaptic (e)NMDA-type glutamate receptor (NMDAR) antagonists, as opposed to antagonists that block physiological phasic synaptic activity, can ameliorate the synaptic and behavioral features of this disease, we utilized the Tsc2+/- mouse model of TSC to measure biochemical, electrophysiological, histological, and behavioral parameters in the mice. We found that antagonists that preferentially block tonic activity as found at eNMDARs, particularly the newer drug NitroSynapsin, provide biological and statistically significant improvement in Tsc2+/- phenotypes. Accompanying this improvement was correction of activity in the p38 MAPK-TSC-Rheb-mTORC1-S6K1 pathway. Deficits in hippocampal long-term potentiation (LTP), histological loss of synapses, and behavioral fear conditioning in Tsc2+/- mice were all improved after treatment with NitroSynapsin. Taken together, these results suggest that amelioration of excessive excitation, by limiting aberrant eNMDAR activity, may represent a novel treatment approach for TSC.


Assuntos
Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Hipocampo/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Esclerose Tuberosa/tratamento farmacológico , Animais , Modelos Animais de Doenças , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/metabolismo , Camundongos , Camundongos Knockout , Esclerose Tuberosa/genética , Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo
10.
BMC Neurol ; 19(1): 324, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842786

RESUMO

BACKGROUND: In this study, we aimed to understand the trends in total and itemized medical expenses, especially of disease-modifying therapy (DMT), for multiple sclerosis (MS) in Japan through an analysis of health insurance claims data. METHODS: We analyzed a database containing health insurance claims data from hospitals that have adopted the Diagnosis Procedure Combination/Per-Diem Payment System in Japan. According to an algorithm based on diagnosis codes, data for all patients diagnosed with MS from April 2008 to July 2016 were extracted. Medical costs, rate of each medical treatment, and rate of relapses were analyzed by calendar-year. Medical costs in the month of relapse were compared with average medical costs per month of all MS patients by a cross-sectional analysis. RESULTS: Four thousand three hundred seventy-four MS patients were identified in the database. Total medical cost per patient per month (PPPM) increased from ¥87,640 (US$787.7 or €723.0 as of May 2017) to ¥102,846 (US$924.4 or €848.4) during the study period. This increment was mainly attributed to the growth in cost of outpatient DMT prescriptions, which increased from ¥23,039 (US$207.1 or €190.1) to ¥51,351 (US$461.5 or €423.6). In contrast, the rate of hospitalizations and relapses PPPM decreased during the study period (from 0.053 to 0.030, and 0.032 to 0.019, respectively). Medical costs in the month of relapse (¥424,661, US$3816.8 or €3503.1) were 3.57 times higher than the average monthly costs for all MS patients (¥119,021, US$1069.8 or €981.8), with the majority comprising hospitalization cost. CONCLUSION: Concomitant with the increased usage of DMT, the total medical cost for treating MS is increasing in Japan. However, rates of relapse and hospitalization have shown a decreasing trend. Although this study does not show the direct causality between DMT and reduction of relapse rates/fewer hospitalizations among MS patients, a reduction in hospital costs has been revealed concomitantly with the increasing prevalence of DMT.


Assuntos
Imunossupressores/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/economia , Adulto , Doença Crônica/economia , Custos e Análise de Custo , Estudos Transversais , Bases de Dados Factuais , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Recidiva
11.
Mol Cell ; 39(2): 184-95, 2010 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-20670888

RESUMO

X-linked inhibitor of apoptosis (XIAP) is a potent antagonist of caspase apoptotic activity. XIAP also functions as an E3 ubiquitin ligase, targeting caspases for degradation. However, molecular pathways controlling XIAP activities remain unclear. Here, we report that nitric oxide (NO) reacts with XIAP by S-nitrosylating its RING domain (forming SNO-XIAP), thereby inhibiting E3 ligase and antiapoptotic activity. NO-mediated neurotoxicity and caspase activation have been linked to several neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's diseases. We find significant SNO-XIAP formation in brains of patients with these diseases, implicating this reaction in the etiology of neuronal damage. Conversely, S-nitrosylation of caspases is known to inhibit apoptotic activity. Unexpectedly, we find that SNO-caspase transnitrosylates (transfers its NO group) to XIAP, forming SNO-XIAP, and thus promotes cell injury and death. These findings provide insights into the regulation of caspase activation in neurodegenerative disorders mediated, at least in part, by nitrosative stress.


Assuntos
Apoptose , Caspases/metabolismo , Óxido Nítrico/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Caspases/genética , Ativação Enzimática/genética , Humanos , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Óxido Nítrico/genética , Estrutura Terciária de Proteína , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética
12.
Gan To Kagaku Ryoho ; 44(13): 2109-2112, 2017 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-29361628

RESUMO

We studied the clinical effects of high-dose methotrexate(HD-MTX)combined with rituximab and vincristine in 5 elderly patients, aged 65-83 years, with diffuse large B-cell lymphoma of the central nervous system(DLBCL CNS). Patients aged 65- 71 years were given 3.0 g/m2 of HD-MTX, while patients aged 75-83 years were given 1.5 g/m2 of the drug. All patients showed responses; 1 CR and 1 PR in MTX 3.0 g/m2 group, and 2 CRs and 1 PR in MTX 1.5 g/m2 group.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Procarbazina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Humanos , Masculino , Metotrexato/administração & dosagem , Rituximab/administração & dosagem , Resultado do Tratamento , Vincristina/administração & dosagem
13.
Biochim Biophys Acta ; 1850(8): 1588-93, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25527866

RESUMO

BACKGROUND: Nitric oxide (NO) is a pleiotropic messenger molecule. The multidimensional actions of NO species are, in part, mediated by their redox nature. Oxidative posttranslational modification of cysteine residues to regulate protein function, termed S-nitrosylation, constitutes a major form of redox-based signaling by NO. SCOPE OF REVIEW: S-Nitrosylation directly modifies a number of cytoplasmic and nuclear proteins in neurons. S-Nitrosylation modulates neuronal development by reaction with specific proteins, including the transcription factor MEF2. This review focuses on the impact of S-nitrosylation on neurogenesis and neuronal development. MAJOR CONCLUSIONS: Functional characterization of S-nitrosylated proteins that regulate neuronal development represents a rapidly emerging field. Recent studies reveal that S-nitrosylation-mediated redox signaling plays an important role in several biological processes essential for neuronal differentiation and maturation. GENERAL SIGNIFICANCE: Investigation of S-nitrosylation in the nervous system has elucidated new molecular and cellular mechanisms for neuronal development. S-Nitrosylated proteins in signaling networks modulate key events in brain development. Dysregulation of this redox-signaling pathway may contribute to neurodevelopmental disabilities such as autism spectrum disorder (ASD). Thus, further elucidation of the involvement of S-nitrosylation in brain development may offer potential therapeutic avenues for neurodevelopmental disorders. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation.


Assuntos
Neurogênese , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Processamento de Proteína Pós-Traducional , Encéfalo/citologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Cisteína/metabolismo , Humanos , Modelos Neurológicos , Neurônios/citologia , Transdução de Sinais , Fatores de Transcrição/metabolismo
14.
Proc Natl Acad Sci U S A ; 110(27): E2518-27, 2013 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-23776240

RESUMO

Synaptic loss is the cardinal feature linking neuropathology to cognitive decline in Alzheimer's disease (AD). However, the mechanism of synaptic damage remains incompletely understood. Here, using FRET-based glutamate sensor imaging, we show that amyloid-ß peptide (Aß) engages α7 nicotinic acetylcholine receptors to induce release of astrocytic glutamate, which in turn activates extrasynaptic NMDA receptors (eNMDARs) on neurons. In hippocampal autapses, this eNMDAR activity is followed by reduction in evoked and miniature excitatory postsynaptic currents (mEPSCs). Decreased mEPSC frequency may reflect early synaptic injury because of concurrent eNMDAR-mediated NO production, tau phosphorylation, and caspase-3 activation, each of which is implicated in spine loss. In hippocampal slices, oligomeric Aß induces eNMDAR-mediated synaptic depression. In AD-transgenic mice compared with wild type, whole-cell recordings revealed excessive tonic eNMDAR activity accompanied by eNMDAR-sensitive loss of mEPSCs. Importantly, the improved NMDAR antagonist NitroMemantine, which selectively inhibits extrasynaptic over physiological synaptic NMDAR activity, protects synapses from Aß-induced damage both in vitro and in vivo.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Astrócitos/metabolismo , Ácido Glutâmico/metabolismo , Inibição Neural/fisiologia , Fragmentos de Peptídeos/toxicidade , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapses/patologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Astrócitos/patologia , Técnicas de Cocultura , Feminino , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Ratos , Receptores Nicotínicos/metabolismo , Sinapses/metabolismo , Receptor Nicotínico de Acetilcolina alfa7
15.
J Neurosci ; 34(13): 4640-53, 2014 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-24672010

RESUMO

Mutations in the ataxia telangiectasia mutated (ATM) gene, which encodes a kinase critical for the normal DNA damage response, cause the neurodegenerative disorder ataxia-telangiectasia (AT). The substrates of ATM in the brain are poorly understood. Here we demonstrate that ATM phosphorylates and activates the transcription factor myocyte enhancer factor 2D (MEF2D), which plays a critical role in promoting survival of cerebellar granule cells. ATM associates with MEF2D after DNA damage and phosphorylates the transcription factor at four ATM consensus sites. Knockdown of endogenous MEF2D with a short-hairpin RNA (shRNA) increases sensitivity to etoposide-induced DNA damage and neuronal cell death. Interestingly, substitution of endogenous MEF2D with an shRNA-resistant phosphomimetic MEF2D mutant protects cerebellar granule cells from cell death after DNA damage, whereas an shRNA-resistant nonphosphorylatable MEF2D mutant does not. In vivo, cerebella in Mef2d knock-out mice manifest increased susceptibility to DNA damage. Together, our results show that MEF2D is a substrate for phosphorylation by ATM, thus promoting survival in response to DNA damage. Moreover, dysregulation of the ATM-MEF2D pathway may contribute to neurodegeneration in AT.


Assuntos
Dano ao DNA/fisiologia , Neurônios/fisiologia , Animais , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/deficiência , Proteínas Mutadas de Ataxia Telangiectasia/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Cerebelo/citologia , Cerebelo/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Células HEK293 , Humanos , Técnicas In Vitro , Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neurônios/citologia , Neurônios/metabolismo , Fosforilação , Regiões Promotoras Genéticas/genética , Interferência de RNA/fisiologia , Superóxidos/metabolismo
16.
Neurobiol Dis ; 84: 99-108, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25796565

RESUMO

Nitric oxide (NO) is a gasotransmitter that impacts fundamental aspects of neuronal function in large measure through S-nitrosylation, a redox reaction that occurs on regulatory cysteine thiol groups. For instance, S-nitrosylation regulates enzymatic activity of target proteins via inhibition of active site cysteine residues or via allosteric regulation of protein structure. During normal brain function, protein S-nitrosylation serves as an important cellular mechanism that modulates a diverse array of physiological processes, including transcriptional activity, synaptic plasticity, and neuronal survival. In contrast, emerging evidence suggests that aging and disease-linked environmental risk factors exacerbate nitrosative stress via excessive production of NO. Consequently, aberrant S-nitrosylation occurs and represents a common pathological feature that contributes to the onset and progression of multiple neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's diseases. In the current review, we highlight recent key findings on aberrant protein S-nitrosylation showing that this reaction triggers protein misfolding, mitochondrial dysfunction, transcriptional dysregulation, synaptic damage, and neuronal injury. Specifically, we discuss the pathological consequences of S-nitrosylated parkin, myocyte enhancer factor 2 (MEF2), dynamin-related protein 1 (Drp1), protein disulfide isomerase (PDI), X-linked inhibitor of apoptosis protein (XIAP), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) under neurodegenerative conditions. We also speculate that intervention to prevent these aberrant S-nitrosylation events may produce novel therapeutic agents to combat neurodegenerative diseases.


Assuntos
Doenças Neurodegenerativas/metabolismo , Proteína S/metabolismo , Animais , Humanos
17.
Int J Lab Hematol ; 46(4): 705-713, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38426662

RESUMO

INTRODUCTION: An investigation of the suitability of reagents for measuring FVIII products in a one-stage clotting assay (OSA) showed variations in their FVIII activity (FVIII:C). Most studies have focused on the activated partial thromboplastin time (APTT) reagent rather than FVIII-deficient plasma (F8DP), even though the APTT-based OSA is comprised of APTT reagents and factor-deficient plasma. AIM: A single-centre study was conducted to clarify variations in measurements of FVIII products in an OSA using a total of 12 reagent combinations, including four APTT reagents and three types of F8DP. METHODS: FVIII:C in nine types of FVIII product-spiked plasma was measured using an OSA with four different APTT reagents and three types of F8DP. RESULTS: F8DP-dependent variations were found in addition to differences derived from APTT reagents. Variations in target recovery (TR) were observed for NovoEight®, Eloctate®, and Jivi®. Reduced TR for Jivi was found only for Pathromtin SL in combination with congenital F8DP (F8DP-3). This lower TR was not observed with alternative manufacturing lots of F8DP-3. The reduced TR for Jivi might be related to impaired contact activation due to lower factor XI activity in F8DP-3. CONCLUSION: In addition to APTT reagents, variations in F8DPs used for OSAs can also affect FVIII:C results. F8DPs as well as the APTT reagent used for OSA should be chosen with caution, and laboratories should evaluate reagents for F8DPs as they currently do for APTT reagents, especially when lot changes occur.


Assuntos
Fator VIII , Humanos , Fator VIII/análise , Tempo de Tromboplastina Parcial/métodos , Tempo de Tromboplastina Parcial/normas , Testes de Coagulação Sanguínea/métodos , Testes de Coagulação Sanguínea/normas , Coagulação Sanguínea , Indicadores e Reagentes , Reprodutibilidade dos Testes
18.
Int J Hematol ; 118(1): 65-74, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37149540

RESUMO

Gene aberrations of B-cell regulators and growth signal components such as the JAK-STAT pathway are frequently found in B-cell acute lymphoblastic leukemia (B-ALL). EBF1 is a B-cell regulator that regulates the expression of PAX5 and co-operates with PAX5 to regulate B-cell differentiation. Here, we analyzed the function of the fusion protein of EBF1 and JAK2, EBF1-JAK2 (E-J). E-J caused constitutive activation of JAK-STAT and MAPK pathways and induced autonomous cell growth in a cytokine-dependent cell line. E-J did not affect the transcriptional activity of EBF1 but inhibited that of PAX5. Both the physical interaction of E-J with PAX5 and kinase activity of E-J were required for E-J to inhibit PAX5 function, although the detailed mechanism of inhibition remains unclear. Importantly, gene set enrichment analysis using the results of our previous RNA-seq data of 323 primary BCR-ABL1-negative ALL samples demonstrated repression of the transcriptional target genes of PAX5 in E-J-positive ALL cells, which suggests that E-J also inhibited PAX5 function in ALL cells. Our results shed new light on the mechanisms of differentiation block by kinase fusion proteins.


Assuntos
Janus Quinases , Fatores de Transcrição STAT , Humanos , Janus Quinases/metabolismo , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Linhagem Celular , Fator de Transcrição PAX5/genética , Fator de Transcrição PAX5/metabolismo , Transativadores/genética , Transativadores/metabolismo , Janus Quinase 2/genética , Janus Quinase 2/metabolismo
19.
Eur J Gastroenterol Hepatol ; 35(10): 1211-1215, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37577802

RESUMO

INTRODUCTION: Although patients with haemophilia are known to develop hepatocellular carcinoma (HCC) at a lower age than patients without, there are few reports on the clinical course and prognosis of HCC. AIM: We aimed to investigate the clinical course and prognosis of patients with HCC and haemophilia. METHODS: Twenty-two patients with haemophilia, who were initially diagnosed with HCC between 2003 and 2021, were included. Their clinical courses and prognoses were retrospectively analysed. The results were compared with those of the 24th Nationwide Follow-up Survey of Primary Liver Cancer. RESULTS: All 22 patients were male; of these, 20 patients had haemophilia A, and 2 had haemophilia B. The mean age of diagnosis was 63 years (range 45-78 years) which is lower than the mean of 72 years reported in the Nationwide Survey. The mean diameter of the largest tumour was 30 mm (range 11-70 mm), and 18 tumours (82%) were solitary at the initial diagnosis. Standard treatments for HCC were performed in all patients. Sixty-one transarterial chemoembolisation, 28 RFA, 10 hepatectomies, and 2 radiation treatments were performed, and molecular-targeted agents were administered to 5 patients during their clinical courses. No deaths were associated with complications of HCC treatments. The median survival time after initial treatment was 6.4 years (range 0.9-18.7 years) which did not differ much from the median survival time of 5.8 years in the Nationwide Survey. CONCLUSION: Standard treatment for HCC could improve the prognosis of patients with HCC and haemophilia.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Hemofilia A , Neoplasias Hepáticas , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/terapia , Hemofilia A/complicações , Hemofilia A/diagnóstico , Hemofilia A/terapia , Estudos Retrospectivos , Quimioembolização Terapêutica/métodos , Prognóstico , Progressão da Doença , Resultado do Tratamento
20.
Medicine (Baltimore) ; 101(29): e29875, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35866765

RESUMO

Coronary artery calcification, an established marker of atherosclerotic plaque burden associated with increased risk of coronary artery disease, is routinely evaluated using electron beam computerized tomography or multidetector computed tomography (CT). However, aortic calcification, which is also a risk factor for adverse cardiac events, is not frequently assessed, despite being easily detected via standard chest radiography. We therefore sought to clarify the association between aortic calcification and significant coronary artery calcification to determine the feasibility of performing chest radiography to evaluate the risk of future cardiovascular events. Data from 682 consecutive patients who underwent cardiac CT scanning at our institution from May to September 2012 were included in this cross-sectional analysis. Electrocardiographic-gated CT was used to qualitatively evaluate calcification in 6 aortic segments. Cardiac contrast-ehnanced CT was performed to identify significant calcification of the coronary artery. Calcification was quantified by calculating the Agatston score, and the relationship between significant coronary artery calcification and calcification at each aortic site was evaluated. Among the aortic sites, calcification was most commonly observed in the aortic arch (77.4% of patients). Significant coronary artery calcification was observed in 267 patients (39.1%). Calcification in the ascending aorta, aortic arch, descending aorta, abdominal aorta, and aortic valve were significantly associated with the presence of coronary artery calcification after adjustment for cardiovascular risk factors and statin use (odds ratios [95% confidence intervals] 4.21 [2.55, 6.93], 1.65 [1.01, 2.69], 2.14 [1.36, 3.36], 2.87 [1.83, 4.50], and 3.32 [2.02, 5.46], respectively). Mitral valve calcification was weakly but nonsignificantly associated with coronary artery calcification (odds ratio 1.84 [95% confidence interval 0.94, 3.62]). Calcification of each aortic segment assessed was significantly associated with Agatston score ≥ 100. Aortic calcification was associated with coronary artery calcification. Calcification of the aortic arch, which can be readily detected by routine chest radiography, may be associated with coronary artery calcification and its assessment should therefore be considered to identify patients at increased risk of cardiovascular events. Further studies are warranted to confirm these findings.


Assuntos
Calcinose , Doença da Artéria Coronariana , Calcificação Vascular , Biomarcadores , Calcinose/complicações , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Estudos Transversais , Humanos , Tomografia Computadorizada Multidetectores , Fatores de Risco , Calcificação Vascular/complicações , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/epidemiologia
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