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1.
Sci Rep ; 13(1): 11583, 2023 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-37463950

RESUMO

In grafted apple, rootstock-derived signals influence scion cold tolerance by initiating physiological changes to survive over the winter. To understand the underlying molecular interactions between scion and rootstock responsive to cold, we developed transcriptomics and metabolomics data in the stems of two scion/rootstock combinations, 'Gala'/'G202' (cold resistant rootstock) and 'Gala'/'M9' (cold susceptible rootstock). Outer layers of scion and rootstock stem, including vascular tissues, were collected from the field-grown grafted apple during the winter. The clustering of differentially expressed genes (DEGs) and gene ontology enrichment indicated distinct expression dynamics in the two graft combinations, which supports the dependency of scion cold tolerance on the rootstock genotypes. We identified 544 potentially mobile mRNAs of DEGs showing highly-correlated seasonal dynamics between scion and rootstock. The mobility of a subset of 544 mRNAs was validated by translocated genome-wide variants and the measurements of selected RNA mobility in tobacco and Arabidopsis. We detected orthologous genes of potentially mobile mRNAs in Arabidopsis thaliana, which belong to cold regulatory networks with RNA mobility. Together, our study provides a comprehensive insight into gene interactions and signal exchange between scion and rootstock responsive to cold. This will serve for future research to enhance cold tolerance of grafted tree crops.


Assuntos
Malus , Malus/genética , Malus/metabolismo , RNA/metabolismo , Perfilação da Expressão Gênica , Metabolômica , Genótipo
2.
J Cardiovasc Dev Dis ; 9(5)2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35621871

RESUMO

(1) Background: Limited data exist on the safety and efficacy of epicardial left ventricular (LV) lead placement using video-assisted thoracoscopic surgery (VATS) for cardiac resynchronization therapy (CRT). (2) Methods: Acute and post-discharge outcomes of CRT were compared between patients with epicardial LV leads (Epicardial-LV group, n = 13) and those with endocardial LV leads (Endocardial-LV group, n = 243). (3) Results: Epicardial LV leads were implanted via VATS alone (n = 8) or along with mini-thoracotomy (n = 5), for failed endocardial implantation (n = 11) or recurrent lead dislodgement (n = 2). All epicardial procedures under general anesthesia with one-lung ventilation were successfully completed in 1.0 ± 0.4 h without phrenic nerve stimulation. LV pacing thresholds in the epicardial-LV (1.5 ± 1.0 V) and endocardial-LV (1.3 ± 0.8 V) were comparable (p = 0.651). All patients were discharged alive post-VATS 8.8 ± 3.9 days. During the follow-up (34.3 ± 28.6 months), all patients with epicardial LV leads stayed alive except for one cardiac death post-CRT 14 months and one heart transplantation post-CRT 30 months. All epicardial LV leads maintained stable performance without dislodgement/significant changes in pacing threshold/impedance. LV lead dislodgement occurred only in endocardial-LV (7/243, 2.9%). Efficacy in both groups was comparable in terms of QRS narrowing, increase in LV ejection fraction, and survival free of cardiac death, or heart-failure-related hospitalization. (4) Conclusions: Epicardial LV lead placement using VATS can be a safe and effective alternative to endocardial implantation, with comparable acute and post-discharge outcomes achieved by both approaches.

3.
Brain Sci ; 11(9)2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34573190

RESUMO

Objective: There is limited literature comparing the uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion outside-in approach (ETLIF (O)) with the inside-out approach (ETLIF (I)). Methods: Radiological evaluation was performed on disc height restoration and coronal wedging angle, and operation time (inferior articular process resection time/total operation time) and clinical evaluation were made. Result: 48 cases of inside-out and 38 cases of outside-in cases were included. Compared to inside-out, the outside-in approach had significantly less operative time required to resect inferior articular process: 36.55 ± 10.37, and total operative time: 87.45 ± 20.14 min compared to 49.83 ± 23.97 and 102.56 ± 36.53 min, respectively, for the inside-out approach, p < 0.05. Compared to the preoperative state, both cohorts achieved significant improvement of VAS and ODI at post-operative 1 week, 3 months and at final follow up. Both cohorts achieved statistically significant increased disc height with 5.00 ± 2.87 mm, 5.49 ± 2.33 mm and statistically significant improvement in coronal wedge angle with 1.76 ± 1.63°, 3.24 ± 2.92° in the inside-out and outside-in approaches respectively. Conclusions: Complete removal of inferior articular process is the key part of endoscopic fusion with two methods that can be applied: an inside-out approach or an outside-in approach. Comparing both techniques, the outside-in approach has a shorter operative time required for inferior articular process resection and total length of operation with similar good clinical and radiological outcomes.

4.
J Med Chem ; 64(20): 15091-15110, 2021 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-34583507

RESUMO

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects movement. The nonreceptor tyrosine kinase c-Abl has shown a potential role in the progression of PD. As such, c-Abl inhibition is a promising candidate for neuroprotection in PD and α-synucleinopathies. Compound 5 is a newly synthesized blood-brain barrier penetrant c-Abl inhibitor with higher efficacy than existing inhibitors. The objective of the current study was to demonstrate the neuroprotective effects of compound 5 on the α-synuclein preformed fibril (α-syn PFF) mouse model of PD. Compound 5 significantly reduced neurotoxicity, activation of c-Abl, and Lewy body pathology caused by α-syn PFF in cortical neurons. Additionally, compound 5 markedly ameliorated the loss of dopaminergic neurons, c-Abl activation, Lewy body pathology, neuroinflammatory responses, and behavioral deficits induced by α-syn PFF injection in vivo. Taken together, these results suggest that compound 5 could be a pharmaceutical agent to prevent the progression of PD and α-synucleinopathies.


Assuntos
Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Relação Dose-Resposta a Droga , Humanos , Modelos Moleculares , Estrutura Molecular , Fármacos Neuroprotetores/química , Doença de Parkinson/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Relação Estrutura-Atividade
5.
Pacing Clin Electrophysiol ; 44(6): 1133-1136, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33619753

RESUMO

We report a case of cardiac intramural arteriovenous malformations (AVMs) misdiagnosed as hypertrophic cardiomyopathy and presented as life-threatening ventricular arrhythmia storm that was successfully controlled by cardiac sympathetic denervation. A 46-year-old male patient with an implantable cardioverter-defibrillator was admitted for recurrent ventricular tachycardia requiring repeated shock refractory to antiarrhythmic drugs. Although the patient was previously diagnosed with hypertrophic cardiomyopathy, multimodality imaging studies showed large left ventricular intramural AVMs, potentially representing arrhythmogenic substrates. Life-threatening ventricular arrhythmia storm, which could not be controlled by radiofrequency catheter ablation and therapeutic hypothermia. However, cardiac sympathetic denervation surgery successfully controlled the ventricular arrhythmia storm.


Assuntos
Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/cirurgia , Imagem Multimodal , Simpatectomia , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/cirurgia , Antiarrítmicos/uso terapêutico , Cardiomiopatia Hipertrófica/diagnóstico , Diagnóstico Diferencial , Eletrocardiografia , Humanos , Masculino , Pessoa de Meia-Idade
6.
Cardiovasc Ultrasound ; 19(1): 5, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407517

RESUMO

BACKGROUND: It is unclear whether increased left ventricular (LV) thickness is associated with worse clinical outcomes in severe aortic stenosis (AS). The aim of this study was to determine the effect of increased LV wall thickness (LVWT) on major clinical outcomes in patients with severe AS. METHODS AND RESULTS: This study included 290 severe AS patients (mean age 69.4 ± 11.0 years; 136 females) between January 2008 and December 2018. For outcome assessment, the endpoint was defined as death from all causes, cardiovascular death, and the aortic valve replacement (AVR) surgery rate. During follow-up (48.7 ± 39.0 months), 157 patients had AVR, 43 patients died, and 28 patients died from cardiovascular causes. Patients with increased LVWT underwent AVR surgery much more than those without LVWT (60.0% vs. 39.0%, p < 0.001). Furthermore, in patients with increased LVWT, the all-cause and cardiovascular death rates were significantly lower in the AVR group than in the non-AVR group (8.8% vs. 27.3%, p < 0.001, 4.8%, vs. 21.0%, p < 0.001). Multivariate analysis revealed that increased LVWT, age, dyspnea, and AVR surgery were significantly correlated with cardiovascular death. CONCLUSIONS: In patients with severe AS, increased LVWT was associated with a higher AVR surgery rate and an increased rate of cardiovascular death independent of other well-known prognostic variates. Thus, these findings suggest that increased LVWT might be used as a potential prognostic factor in severe AS patients.


Assuntos
Estenose da Valva Aórtica/diagnóstico , Valva Aórtica/diagnóstico por imagem , Ecocardiografia/métodos , Implante de Prótese de Valva Cardíaca , Ventrículos do Coração/diagnóstico por imagem , Função Ventricular Esquerda/fisiologia , Idoso , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/cirurgia , Progressão da Doença , Feminino , Seguimentos , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença
7.
Sci Rep ; 10(1): 14756, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901093

RESUMO

Liver fibrosis, a common outcome of chronic liver disease characterized by excessive accumulation of extracellular matrix (ECM), is a leading cause of mortality worldwide. The tyrosine kinase inhibitor neratinib is a human epidermal growth factor receptor 2 (HER2) inhibitor approved by the FDA for HER2-positive breast cancer treatment; however, it has not yet been evaluated for liver fibrosis treatment. We elucidated the anti-fibrotic effects of neratinib in hepatic stellate cells (HSCs) and in vivo models of CCl4-induced liver fibrosis. HSC activation is a key step in liver fibrogenesis and has a crucial role in collagen deposition, as it is primarily responsible for excessive ECM production. The effect of neratinib on HSC was evaluated in transforming growth factor (TGF-ß)-incubated LX-2 cells and culture-activated primary human HSCs. In vivo study results indicated that neratinib inhibited the inflammatory response, HSC differentiation, and collagen accumulation induced by CCl4. Moreover, the anti-fibrotic effects of neratinib were not associated with the HER2 signaling pathways. Neratinib inhibited FGF2 expression in activated HSCs and serum FGF2 level in the model, suggesting that neratinib possessed therapeutic potency against liver fibrosis and the potential for application against other fibrotic diseases.


Assuntos
Fator 2 de Crescimento de Fibroblastos/antagonistas & inibidores , Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática/prevenção & controle , Inibidores de Proteínas Quinases/farmacologia , Quinolinas/farmacologia , Animais , Tetracloreto de Carbono/toxicidade , Proliferação de Células , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/enzimologia , Cirrose Hepática/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais
8.
Nat Commun ; 10(1): 1128, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850660

RESUMO

Scleroderma is an autoimmune rheumatic disorder accompanied by severe fibrosis in skin and other internal organs. During scleroderma progression, resident fibroblasts undergo activation and convert to α-smooth muscle actin (α-SMA) expressing myofibroblasts (MFBs) with increased capacity to synthesize collagens and fibrogenic components. Accordingly, MFBs are a major therapeutic target for fibrosis in scleroderma and treatment with blocking MFBs could produce anti-fibrotic effects. TLY012 is an engineered human TNF-related apoptosis-inducing ligand (TRAIL) which induces selective apoptosis in transformed cells expressing its cognate death receptors (DRs). Here we report that TLY012 selectively blocks activation of dermal fibroblasts and induces DR-mediated apoptosis in α-SMA+ MFBs through upregulated DR5 during its activation. In vivo, TLY012 reverses established skin fibrosis to near-normal skin architecture in mouse models of scleroderma. Thus, the TRAIL pathway plays a critical role in tissue remodeling and targeting upregulated DR5 in α-SMA+ MFBs is a viable therapy for fibrosis in scleroderma.


Assuntos
Actinas/genética , Derme/efeitos dos fármacos , Miofibroblastos/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Escleroderma Sistêmico/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Actinas/metabolismo , Adulto , Idoso , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Diferenciação Celular , Colágeno/genética , Colágeno/metabolismo , Derme/metabolismo , Derme/patologia , Modelos Animais de Doenças , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Miofibroblastos/metabolismo , Miofibroblastos/patologia , Engenharia de Proteínas , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Escleroderma Sistêmico/genética , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/patologia , Transdução de Sinais
10.
J Control Release ; 267: 163-171, 2017 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-29017854

RESUMO

TNF-related apoptosis-inducing ligand (TRAIL) is a death ligand that can induce apoptosis in cells expressing its cognate death receptors (DRs). Previously, we demonstrated the therapeutic potential of recombinant human TRAIL in experimental rheumatoid arthritis (RA) models. However, the mechanisms of how DR-mediated apoptosis elicits these actions is not known. Here, we show that systemically administering a potent, long-acting PEGylated TRAIL (TRAILPEG) is profoundly anti-rheumatic against two complementary experimental RA mouse models, collagen-induced arthritis (CIA) and collagen antibody-induced arthritis (CAIA), via targeting IL-17 secreting Th17 cells and regulatory T cells (Treg). Systemic administration of TRAILPEG after disease onset ameliorated the severity of inflammatory arthritis including arthritis indices, paw thickness, cartilage damage and neutrophil infiltration in both CIA and CAIA models. Additionally, the levels of inflammatory molecules (p-p65, ICAM-1, Cox-2, MMP3, and iNOS), pro-inflammatory cytokines (TNF-α, IL-1ß, IFN-γ, IL-6, IL-17) and accumulation of activated macrophages were significantly reduced after the TRAILPEG treatment. Importantly, TRAILPEG decreased the number of pro-inflammatory Th17 cells in inflamed arthritic joints through TRAIL-induced apoptosis while increasing anti-inflammatory Treg population in vivo. These results suggest that TRAILPEG ameliorates autoimmunity by targeting the Th 17-Tregs axis, making it a promising candidate drug for the treatment of RA.


Assuntos
Artrite Experimental/tratamento farmacológico , Polietilenoglicóis/administração & dosagem , Ligante Indutor de Apoptose Relacionado a TNF/administração & dosagem , Animais , Artrite Experimental/genética , Artrite Experimental/imunologia , Artrite Experimental/patologia , Citocinas/sangue , Citocinas/genética , Citocinas/imunologia , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/imunologia , Articulação do Joelho/patologia , Masculino , Camundongos Endogâmicos DBA , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polietilenoglicóis/uso terapêutico , RNA Mensageiro/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/química , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/uso terapêutico
11.
Hepatology ; 64(1): 209-23, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26710118

RESUMO

UNLABELLED: Liver fibrosis is a common outcome of chronic liver disease that leads to liver cirrhosis and hepatocellular carcinoma. No US Food and Drug Administration-approved targeted antifibrotic therapy exists. Activated hepatic stellate cells (aHSCs) are the major cell types responsible for liver fibrosis; therefore, eradication of aHSCs, while preserving quiescent HSCs and other normal cells, is a logical strategy to stop and/or reverse liver fibrogenesis/fibrosis. However, there are no effective approaches to specifically deplete aHSCs during fibrosis without systemic toxicity. aHSCs are associated with elevated expression of death receptors and become sensitive to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death. Treatment with recombinant TRAIL could be a potential strategy to ameliorate liver fibrosis; however, the therapeutic application of recombinant TRAIL is halted due to its very short half-life. To overcome this problem, we previously generated PEGylated TRAIL (TRAILPEG ) that has a much longer half-life in rodents than native-type TRAIL. In this study, we demonstrate that intravenous TRAILPEG has a markedly extended half-life over native-type TRAIL in nonhuman primates and has no toxicity in primary human hepatocytes. Intravenous injection of TRAILPEG directly induces apoptosis of aHSCs in vivo and ameliorates carbon tetrachloride-induced fibrosis/cirrhosis in rats by simultaneously down-regulating multiple key fibrotic markers that are associated with aHSCs. CONCLUSION: TRAIL-based therapies could serve as new therapeutics for liver fibrosis/cirrhosis and possibly other fibrotic diseases. (Hepatology 2016;64:209-223).


Assuntos
Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática/tratamento farmacológico , Ligante Indutor de Apoptose Relacionado a TNF/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Tetracloreto de Carbono , Avaliação Pré-Clínica de Medicamentos , Hepatócitos/efeitos dos fármacos , Humanos , Injeções Intravenosas , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Ratos Sprague-Dawley , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Regulação para Cima
12.
Mol Ther ; 22(2): 397-408, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24145554

RESUMO

Among various proinflammatory cytokines involved in the pathogenesis of rheumatoid arthritis (RA), tumor necrosis factor (TNF)-α plays a pivotal role in the release of other cytokines and induction of chronic inflammation. Even though siRNA has the therapeutic potential, they have a challenge to be delivered into the target cells because of their poor stability in physiological fluids. Herein, we design a nanocomplex of polymerized siRNA (poly-siRNA) targeting TNF-α with thiolated glycol chitosan (tGC) polymers for the treatment of RA. Poly-siRNA is prepared through self-polymerization of thiol groups at the 5' end of sense and antisense strand of siRNA and encapsulated into tGC polymers, resulting in poly-siRNA-tGC nanoparticles (psi-tGC-NPs) with an average diameter of 370 nm. In the macrophage culture system, psi-tGC-NPs exhibit rapid cellular uptake and excellent in vitro TNF-α gene silencing efficacy. Importantly, psi-tGC-NPs show the high accumulation at the arthritic joint sites in collagen-induced arthritis (CIA) mice. Treatment monitoring data obtained by the matrix metalloproteinase 3-specific nanoprobe and microcomputed tomography show that intravenous injection of psi-tGC-NPs significantly inhibits inflammation and bone erosion in CIA mice, comparable to methotrexate (5 mg/kg). Therefore, the availability of psi-tGC-NP therapy that target specific cytokines may herald new era in the treatment of RA.


Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/terapia , Quitosana , Inativação Gênica , Nanopartículas , RNA Interferente Pequeno/genética , Compostos de Sulfidrila , Fator de Necrose Tumoral alfa/genética , Animais , Artrite Experimental , Artrite Reumatoide/patologia , Linhagem Celular , Quitosana/química , Modelos Animais de Doenças , Expressão Gênica , Macrófagos/metabolismo , Masculino , Camundongos , Nanopartículas/química , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/química , Compostos de Sulfidrila/química , Resultado do Tratamento , Fator de Necrose Tumoral alfa/sangue
13.
Neurobiol Dis ; 62: 286-95, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24141018

RESUMO

Recent findings suggest that Notch-1 signaling contributes to neuronal death in ischemic stroke, but the underlying mechanisms are unknown. Hypoxia inducible factor-1α (HIF-1α), a global regulator of cellular responses to hypoxia, can interact with Notch and modulate its signaling during hypoxic stress. Here we show that Notch signaling interacts with the HIF-1α pathway in the process of ischemic neuronal death. We found that a chemical inhibitor of the Notch-activating enzyme, γ-secretase, and a HIF-1α inhibitor, protect cultured cortical neurons against ischemic stress, and combined inhibition of Notch-1 and HIF-1α further decreased neuronal death. HIF-1α and Notch intracellular domain (NICD) are co-expressed in the neuronal nucleus, and co-immunoprecipitated in cultured neurons and in brain tissue from mice subjected to focal ischemic stroke. Overexpression of NICD and HIF-1α in cultured human neural cells enhanced cell death under ischemia-like conditions, and a HIF-1α inhibitor rescued the cells. RNA interference-mediated depletion of endogenous NICD and HIF-1α also decreased cell death under ischemia-like conditions. Finally, mice treated with inhibitors of γ-secretase and HIF-1α exhibited improved outcome after focal ischemic stroke, with combined treatment being superior to individual treatments. Additional findings suggest that the NICD and HIF-1α collaborate to engage pro-inflammatory and apoptotic signaling pathways in stroke.


Assuntos
Isquemia Encefálica/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neurônios/metabolismo , Receptor Notch1/metabolismo , Acidente Vascular Cerebral/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Morte Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Humanos , Infarto da Artéria Cerebral Anterior/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/metabolismo
14.
Mol Pharmacol ; 80(1): 23-31, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21450930

RESUMO

Notch-1 (Notch) is a cell surface receptor that regulates cell-fate decisions in the developing nervous system, and it may also have roles in synaptic plasticity in the adult brain. Binding of its ligands results in the proteolytic cleavage of Notch by the γ-secretase enzyme complex, thereby causing the release of a Notch intracellular domain (NICD) that translocates to the nucleus, in which it regulates transcription. Here we show that activation of Notch modulates ischemic neuronal cell death in vitro and in vivo. Specifically, our findings from the use of Notch-1 siRNA or the overexpression of NICD indicate that Notch activation contributes to cell death. Using modified NICD, we demonstrate an apoptosis-inducing function of NICD in both the nucleus and the cytosol. NICD transfection-induced cell death was reduced by blockade of calcium signaling, caspase activation, and Janus kinase signaling. Inhibition of the Notch-activating enzyme, γ-secretase, protected against ischemic neuronal cell death by targeting an apoptotic protease, cleaved caspase-3, nuclear factor-κB (NF-κB), and the pro-death BH3-only protein, Bcl-2-interacting mediator of cell death (Bim). Treatment of mice with a γ-secretase inhibitor, compound E, reduced infarct size and improved functional outcome in a model of focal ischemic stroke. Furthermore, γ-secretase inhibition reduced NICD, p-p65, and Bim levels in vivo. These findings suggest that Notch signaling endangers neurons after ischemic stroke by modulating the NF-κB, pro-death protein Bim, and caspase pathways.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Isquemia Encefálica/patologia , Morte Celular/fisiologia , NF-kappa B/metabolismo , Neurônios/citologia , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Receptores Notch/metabolismo , Transdução de Sinais , Acidente Vascular Cerebral/patologia , Animais , Isquemia Encefálica/enzimologia , Isquemia Encefálica/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Ratos Sprague-Dawley , Acidente Vascular Cerebral/enzimologia , Acidente Vascular Cerebral/metabolismo
15.
BMB Rep ; 44(2): 135-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21345314

RESUMO

Chronic alcohol consumption contributes to numerous diseases, including cancers, cardiovascular diseases, and liver cirrhosis. Epidemiological studies have shown that excessive alcohol consumption is a risk factor for dementia. Along this line, Alzheimer's disease (AD) is the most common form of dementia and is caused by the accumulation of amyloid-ß (Aß plaques in neurons. In this study, we hypothesized that chronic ethanol consumption is associated with pathological processing of APP in AD. To investigate the relationship between chronic alcohol consumption and Aß production, brain samples from rats fed an alcohol liquid diet for 5 weeks were analyzed. We show that the expression levels of APP, BACE1, and immature nicastrin were increased in the cerebellum, hippocampus, and striatum of the alcohol-fed group compared to the control group. Total nicastrin and PS1 levels were induced in the hippocampus of alcohol-fed rats. These data suggest that the altered expression of APP and Aß-producing enzymes possibly contributes to the chronic alcohol consumption-mediated pathogenesis of AD.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Etanol/farmacologia , Animais , Encéfalo/enzimologia , Encéfalo/metabolismo , Cerebelo/enzimologia , Cerebelo/metabolismo , Hipocampo/enzimologia , Hipocampo/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Ratos , Ratos Sprague-Dawley
16.
Neurobiol Aging ; 31(6): 917-25, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18687504

RESUMO

Beta-secretase (BACE1), an enzyme responsible for the production of amyloid beta-peptide (Abeta), is increased by oxidative stress and is elevated in the brains of patients with sporadic Alzheimer's disease (AD). Here, we show that oxidative stress fails to induce BACE1 expression in presenilin-1 (gamma-secretase)-deficient cells and in normal cells treated with gamma-secretase inhibitors. Oxidative stress-induced beta-secretase activity and sAPPbeta levels were suppressed by gamma-secretase inhibitors. Levels of gamma- and beta-secretase activities were greater in brain tissue samples from AD patients compared to non-demented control subjects, and the elevated BACE1 level in the brains of 3xTgAD mice was reduced by treatment with a gamma-secretase inhibitor. Our findings suggest that gamma-secretase mediates oxidative stress-induced expression of BACE1 resulting in excessive Abeta production in AD.


Assuntos
Doença de Alzheimer/enzimologia , Doença de Alzheimer/patologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Aldeídos/farmacologia , Secretases da Proteína Precursora do Amiloide/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Análise de Variância , Doenças dos Animais , Animais , Ácido Aspártico Endopeptidases/genética , Encéfalo/enzimologia , Células Cultivadas , Relação Dose-Resposta a Droga , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Camundongos Transgênicos , Mutação/genética , Neuroblastoma/patologia , Oxidantes/farmacologia , Estresse Oxidativo/genética , Fragmentos de Peptídeos/metabolismo , Presenilina-1/genética , Presenilina-2/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/farmacologia , Proteínas tau/genética
17.
Neurosci Lett ; 469(3): 425-8, 2010 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-20035833

RESUMO

Presenilins are the catalytic subunit of the large gamma-secretase complex, that promotes intramembranous proteolysis of the beta-amyloid precursor protein (APP), resulting in the production of beta-amyloid (A beta). Mutant presenilin causes early-onset familial Alzheimer's disease (FAD), is related to abnormal Ca(2+) signaling, and render cells vulnerable to cell death. In the present study, we demonstrated that Ca(2+)-mediated cell death is functionally associated with gamma-secretase activity. We found that gamma-secretase activity was elevated during Ca(2+)-mediated cell death. Using selective gamma-secretase inhibitors, we examined the role of gamma-secretase in cell death triggered by increased intracellular Ca(2+). Indeed, treatment with the selective gamma-secretase inhibitors, compound E, DAPT, or L-685.458 significantly decreased Ca(2+)-triggered cell death with that of the controls, but did not affect staurosporin or tunicamycin-mediated cell death. These results implicate the role of gamma-secretase activity in Ca(2+)-mediated cell death.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Cálcio/metabolismo , Neurônios/enzimologia , Neurônios/fisiologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Hipocampo/fisiologia , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/enzimologia , Espaço Intracelular/fisiologia , Neurônios/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
18.
Neurosci Lett ; 469(3): 391-5, 2010 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-20026385

RESUMO

The objective of the present study was to examine the role of selenium in the metabolism of A beta and in A beta-induced neuronal death. Selenium treatment significantly reduced A beta 40, A beta 42, and sAPP beta production by reducing A beta producing beta-secretase and gamma-secretase activities. The lipid peroxidation product 4-Hydroxynonenal (HNE)-induced transcription of beta-secretase (BACE1) was blocked by selenium. Finally, our data show that selenium protects against HNE and A beta-mediated toxicity in primary cultured neurons. The present study suggests that selenium may be able to salvage the neuronal degeneration of Alzheimer's disease, thereby limiting beta-amyloid production and neuronal death.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Fármacos Neuroprotetores/farmacologia , Selênio/farmacologia , Aldeídos/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular Tumoral , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/fisiologia , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Ratos
19.
Biochem Biophys Res Commun ; 390(4): 1093-7, 2009 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-19853579

RESUMO

Cleavage of the amyloid precursor protein (APP) by gamma-secretase generates a neurotoxic amyloid beta-peptide (Abeta) that is thought to be associated with the neurodegeneration observed in Alzheimer's disease (AD) patients. Presenilin is the catalytic member of the gamma-secretase proteolytic complex and mutations in presenilins are the major cause of early-onset familial Alzheimer's disease. In addition to APP, gamma-secretase substrates include Notch1 homologues, Notch ligands Delta and Jagged, and additional type I membrane proteins, raising concerns about mechanism-based toxicities that might arise as a consequence of inhibiting gamma-secretase. Notch signaling is involved in tumorigenesis as well as in determining the fates of neural and nonneural cells during development and in adults. Alterations in proteolysis of the Notch by gamma-secretase could be involved in the pathogenesis of AD. Inconsistently, several recent observations have indicated that enhanced Notch signaling and expression could be instrumental in neurodegeneration in AD. Therefore, detailed and precise study of Notch signaling in AD is important for elucidating diverse mechanisms of pathogenesis and potentially for treating and preventing Alzheimer's disease.


Assuntos
Doença de Alzheimer/metabolismo , Receptor Notch1/metabolismo , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Humanos , Transdução de Sinais
20.
Plant Cell ; 19(5): 1649-64, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17513504

RESUMO

Loss of green color in leaves results from chlorophyll (Chl) degradation in chloroplasts, but little is known about how Chl catabolism is regulated throughout leaf development. Using the staygreen (sgr) mutant in rice (Oryza sativa), which maintains greenness during leaf senescence, we identified Sgr, a senescence-associated gene encoding a novel chloroplast protein. Transgenic rice overexpressing Sgr produces yellowish-brown leaves, and Arabidopsis thaliana pheophorbide a oxygenase-impaired mutants exhibiting a stay-green phenotype during dark-induced senescence have reduced expression of Sgr homologs, indicating that Sgr regulates Chl degradation at the transcriptional level. We show that the leaf stay-greenness of the sgr mutant is associated with a failure in the destabilization of the light-harvesting chlorophyll binding protein (LHCP) complexes of the thylakoid membranes, which is a prerequisite event for the degradation of Chls and LHCPs during senescence. Transient overexpression of Sgr in Nicotiana benthamiana and an in vivo pull-down assay show that Sgr interacts with LHCPII, indicating that the Sgr-LHCPII complexes are formed in the thylakoid membranes. Thus, we propose that in senescing leaves, Sgr regulates Chl degradation by inducing LHCPII disassembly through direct interaction, leading to the degradation of Chls and Chl-free LHCPII by catabolic enzymes and proteases, respectively.


Assuntos
Senescência Celular , Clorofila/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Arabidopsis/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Cromatografia Líquida de Alta Pressão , Escuridão , Genes de Plantas , Membranas Intracelulares/metabolismo , Membranas Intracelulares/ultraestrutura , Complexos de Proteínas Captadores de Luz/metabolismo , Dados de Sequência Molecular , Mutação/genética , Oryza/genética , Oryza/ultraestrutura , Fenótipo , Folhas de Planta/citologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/química , Proteínas de Plantas/genética , Ligação Proteica , Homologia de Sequência de Aminoácidos , Termodinâmica , Tilacoides/metabolismo , Tilacoides/ultraestrutura , Nicotiana/metabolismo
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