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1.
Artigo em Inglês | MEDLINE | ID: mdl-38833402

RESUMO

Talking face generation aims at generating photorealistic video portraits of a target person driven by input audio. According to the nature of audio to lip motions mapping, the same speech content may have different appearances even for the same person at different occasions. Such one-to-many mapping problem brings ambiguity during training and thus causes inferior visual results. Although this one-to-many mapping could be alleviated in part by a two-stage framework (i.e., an audioto- expression model followed by a neural-rendering model), it is still insufficient since the prediction is produced without enough information (e.g., emotions, wrinkles, etc.). In this paper, we propose MemFace to complement the missing information with an implicit memory and an explicit memory that follow the sense of the two stages respectively. More specifically, the implicit memory is employed in the audio-to-expression model to capture high-level semantics in the audio-expression shared space, while the explicit memory is employed in the neural-rendering model to help synthesize pixel-level details. Our experimental results show that our proposed MemFace surpasses all the state-of-theart results across multiple scenarios consistently and significantly.

2.
Front Neurol ; 15: 1331537, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38523609

RESUMO

Background: Previous research has yielded conflicting results on the link between epilepsy risk and lipid-lowering medications. The aim of this study is to determine whether the risk of epilepsy outcomes is causally related to lipid-lowering medications predicted by genetics. Methods: We used genetic instruments as proxies to the exposure of lipid-lowering drugs, employing variants within or near genes targeted by these drugs and associated with low-density lipoprotein cholesterol (LDL cholesterol) from a genome-wide association study. These variants served as controlling factors. Through drug target Mendelian randomization, we systematically assessed the impact of lipid-lowering medications, including HMG-CoA reductase (HMGCR) inhibitors, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, and Niemann-Pick C1-like 1 (NPC1L1) inhibitors, on epilepsy. Results: The analysis demonstrated that a higher expression of HMGCR was associated with an elevated risk of various types of epilepsy, including all types (OR = 1.17, 95% CI:1.03 to 1.32, p = 0.01), focal epilepsy (OR = 1.24, 95% CI:1.08 to 1.43, p = 0.003), and focal epilepsy documented with lesions other than hippocampal sclerosis (OR = 1.05, 95% CI: 1.01 to 1.10, p = 0.02). The risk of juvenile absence epilepsy (JAE) was also associated with higher expression of PCSK9 (OR = 1.06, 95% CI: 1.02 to 1.09, p = 0.002). For other relationships, there was no reliable supporting data available. Conclusion: The drug target MR investigation suggests a possible link between reduced epilepsy vulnerability and HMGCR and PCSK9 inhibition.

3.
J Neuropathol Exp Neurol ; 83(3): 194-204, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38230623

RESUMO

Hemorrhagic transformation can complicate ischemic strokes after recanalization treatment within a time window that requires early intervention. To determine potential therapeutic effects of matrilin-3, rat cerebral ischemia-reperfusion was produced using transient middle cerebral artery occlusion (tMCAO); intracranial hemorrhage and infarct volumes were assayed through hemoglobin determination and 2,3,5-triphenyltetrazoliumchloride (TTC) staining, respectively. Oxygen-glucose deprivation (OGD) modeling of ischemia was performed on C8-D1A cells. Interactions between matrilin-3 and YTH N6-methyladenosine RNA binding protein F2 (YTHDF2) were determined using RNA immunoprecipitation assay and actinomycin D treatment. Reperfusion after tMCAO modeling increased hemorrhage, hemoglobin content, and infarct volumes; these were alleviated by matrilin treatment. Matrilin-3 was expressed at low levels and YTHDF2 was expressed at high levels in ischemic brains. In OGD-induced cells, matrilin-3 was negatively regulated by YTHDF2. Matrilin-3 overexpression downregulated p-PI3K/PI3K, p-AKT/AKT, ZO-1, VE-cadherin and occludin, and upregulated p-JNK/JNK in ischemic rat brains; these effects were reversed by LY294002 (a PI3K inhibitor). YTHDF2 knockdown inactivated the PI3K/AKT pathway, inhibited inflammation and decreased blood-brain barrier-related protein levels in cells; these effects were reversed by matrilin-3 deficiency. These results indicate that YTHDF2-regulated matrilin-3 protected ischemic rats against post-reperfusion hemorrhagic transformation via the PI3K/AKT pathway and that matrilin may have therapeutic potential in ischemic stroke.


Assuntos
Isquemia Encefálica , AVC Isquêmico , Fármacos Neuroprotetores , Traumatismo por Reperfusão , Ratos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Matrilinas/farmacologia , Proteínas Matrilinas/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Ratos Sprague-Dawley , Isquemia Encefálica/metabolismo , Hemorragia , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Fatores de Transcrição , Reperfusão , Hemoglobinas/farmacologia , Hemoglobinas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico
4.
Int J Biol Macromol ; 255: 128109, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37979742

RESUMO

Oat protein is becoming an important ingredient in beverages and formulated foods owing to its high nutritive value and bland flavor; yet, its functionality remains largely unexplored. This study sought to enhance the surface activity of oat protein isolate (OPI) through high-intensity ultrasound (HIU; at 20 or 60 °C) combined with high pressure homogenization (HP; 30 MPa) treatments. Sonication disturbed the protein conformation and significantly improved surface hydrophobicity (19.7%) and ζ-potential (15.7%), which were further augmented by subsequent HP (P < 0.05). Confocal microscopy revealed a uniform oil droplet distribution in emulsions prepared with HIU+HP combination treated OPI, and the oil droplet size decreased up to 35.6% when compared to that of non-treated OPI emulsion (d = 1718 nm). Emulsifying activity was greater for HIU+HP than for HIU, and the viscosity followed a similar trend. Moreover, while emulsions prepared with HIU or HP treated OPI were more stable than control, the 60 °C HIU+HP combination treatment yielded the maximum stability. In corroboration, a model salad dressing prepared from HIU+HP treated OPI displayed a homogenous oil droplet distribution and an improved viscosity. Therefore, thermosonication combined with high pressure homogenization may be suitable for salad dressings and other oil-imbedded food products.


Assuntos
Avena , Condimentos , Emulsões/química , Viscosidade , Interações Hidrofóbicas e Hidrofílicas
5.
Meat Sci ; 201: 109187, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37086702

RESUMO

The effects of different concentrations of eugenol (EG = 0, 5, 10, 20, 50, and 100 mg/g protein) on the structural properties and gelling behavior of myofibrillar proteins (MPs) were investigated. The interaction of EG and MPs decreased free thiol and amine content, and reduced tryptophan fluorescence intensity and thermal stability, but enhanced surface hydrophobicity and aggregation of MPs. Compared with the control (EG free), the MPs' gels treated with 5 and 10 mg/g of EG had a higher storage modulus, compressive strength, and less cooking loss. A high microscopic density was observed in these EG-treated gels. However, EG at 100 mg/g was detrimental to the gelling properties of the MPs. The results indicate that an EG concentration of 20 mg/g is a turning point, i.e., below 20 mg/g, EG promoted MPs gelation, but above 20 mg/g, it impeded gelation by interfering with protein network formation. The EG modification of MPs could provide a novel ingredient strategy to improve the texture of comminuted meat products.


Assuntos
Eugenol , Proteínas Musculares , Suínos , Animais , Proteínas Musculares/química , Eugenol/farmacologia , Oxirredução , Interações Hidrofóbicas e Hidrofílicas , Géis/química , Reologia , Miofibrilas/química
6.
Food Chem ; 404(Pt A): 134511, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36240566

RESUMO

Disulfide bonds play an essential structural role but may hinder the molecular flexibility and functionality of proteins. The present study investigated the effect of disulfide cleavage on emulsifying activity of oat protein isolate (OPI). Four reducing agents tested (dithiothreitol, ascorbic acid, cysteine, and sodium bisulfite) except ascorbic acid disrupted inter-subunit SS bonds of OPI (up to 90 %) in a dose-dependent manner. Emulsification properties were measured specifically on cysteine-modified OPI, and the results showed increased emulsifying activity up to 37 % after subunit dissociation, which exposed hydrophobic groups and loosened the structure. In particular, emulsions formed by cysteine-treated OPI (1.7 to 6.7 mM/mg protein) displayed a superior interfacial protein coverage (0.170 m2/mg compared to 0.092 m2/mg for control) and reduced emulsion particle size (from 4722 to 2238 nm). The application of cysteine as a structure-modifying food additive can broaden the utilization of oat protein in emulsion-based food products.


Assuntos
Avena , Dissulfetos , Emulsões/química , Dissulfetos/química , Cisteína , Ácido Ascórbico , Emulsificantes/química
7.
Food Chem X ; 16: 100509, 2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36519106

RESUMO

The purpose of this study is to investigate the impact of varied oil body (OB) concentrations and interfacial compositions on the network topology and rheological and functional aspects of composite whey protein isolate (WPI) gels. Particle size and ζ-potential analyzes of the mixed gel solutions containing the OBs extracted at pH 6.8 (6.8-OB) and 11.0 (11.0-OB) revealed a greater aggregation in the 6.8-OB-containing mixed gel solution. 6.8-OB and 11.0-OB generated particle aggregates and oil-drop-embedded network architectures in the WPI gel, respectively. FT-IR analyses showed that OBs stabilized the protein gels' polymeric matrix by hydrogen bonding, steric hindrance, and hydrophobic interactions. Rheology and texture showed that OBs hardened gels. Low-field nuclear magnetic resonance showed that excessive inclusion of OBs (30% of 6.8-OB and 35% of 11.0-OB) compromised gel integrity and freeze-thaw stability. This study found that OBs can be active fillers in protein gels for functional meals.

8.
Front Microbiol ; 13: 864246, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35875567

RESUMO

Methicillin-resistant Staphylococcus epidermidis (MRSE) is one of the most commonly found pathogens that may cause uncontrollable infections in immunocompromised and hospitalized patients. Compounds isolated from cinnamon such as cinnamaldehyde and cinnamic acid showed promising anti-oxidant, anti-tumor, and immunoregulatory effects; more importantly, these compounds also possess promising broad-spectrum antibacterial activity. In this study, the potential antibacterial activity of 2-methoxycinnamaldehyde (MCA), another compound in cinnamon, against MRSE was investigated. Combining the broth microdilution test, live/dead assay, and biofilm formation assay, we found MCA was able to inhibit the proliferation, as well as the biofilm formation of MRSE, indicating MCA could not only affect the growth of MRSE but also inhibit the pathogenic potential of this bacterium. Additionally, the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that MCA caused morphological changes and the leakage of DNA, RNA, and cellular contents of MRSE. Due to the close relationship between cell wall synthesis, ROS formation, and cell metabolism, the ROS level and metabolic profile of MRSE were explored. Our study showed MCA significantly increased the ROS production in MRSE, and the following metabolomics analysis showed that the increased ROS production may partially be due to the increased metabolic flux through the TCA cycle. In addition, we noticed the metabolic flux through the pentose phosphate pathway (PPP) was upregulated accompanied by elevated ROS production. Therefore, the alterations in cell metabolism and increased ROS production could lead to the damage of the cell wall, which in turn decreased the proliferation of MRSE. In conclusion, MCA seemed to be a promising alternative antimicrobial agent to control MRSE infections.

9.
J Food Sci ; 86(1): 78-85, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33249568

RESUMO

Understanding the relationship between ionic strength and protein solubility is essential to the utilization of salt in the formulation design of plant protein-based food and beverage products. In this study, suspensions of oat protein isolate (OPI) were treated with two kinds of common salts (sodium chloride NaCl; sodium phosphate NaP) at different ionic strengths (I). Electrical conductivity, protein solubility, particle size, and protein profile (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) were analyzed. The results showed the highest protein solubility at extremely low I (< 0.005 for NaCl; < 0.012 for NaP) and a minimum solubility at I 0.03 to 0.2 depending on the type of salt. Particle size and electrophoretic patterns supported the solubility profile. The combination effect of ionic strength and pH was also investigated. A characteristic U-shaped solubility curve observed within pH 2.0 to 8.0 at low ionic strengths (I < 0.01) was altered by increasing the salt concentration. The findings demonstrate that ionic strength and ion species play a crucial role in oat protein solubility, and the ionic effect can be modified by changing the pH. Therefore, the application of appropriate salt concentrations is vitally important to the manufacture of oat protein-based food products. PRACTICAL APPLICATION: Sodium chloride and phosphate are two of the most widely utilized salts in food processing. This study highlights the relationship between ionic strength of the two salts and oat protein solubility at different pH levels, providing useful information for selecting proper salt concentrations in the manufacture of oat protein-based food products.


Assuntos
Avena/química , Manipulação de Alimentos/métodos , Proteínas de Plantas/química , Concentração de Íons de Hidrogênio , Íons , Concentração Osmolar , Tamanho da Partícula , Fosfatos/química , Cloreto de Sódio/química , Solubilidade
10.
J Agric Food Chem ; 67(18): 5122-5134, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30995031

RESUMO

Neuroinflammation has been intensively demonstrated to be related to various neurodegenerative diseases including Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Alzheimer's disease (AD). A natural polymethoxylated flavone, nobiletin (NOB) has been reported to alleviate oxidative stress, insulin resistance, and obesity. In this study, we evaluated the protection effects of NOB on neuroinflammation and memory deficit. Three-month mice were administrated with NOB by oral gavage every day for 6 weeks (100 mg/kg/day); subsequently mice were injected intraperitoneally with lipopolysaccharide (LPS) for 7 days. Results of behavioral tests revealed that NOB dramatically ameliorated LPS-triggered memory deficit regarding synaptic dysfunctions and neuronal loss. Also, NOB suppressed the microglial activation and proinflammatory cytokine secretion, such as COX-2, IL-1ß, TNF-α, and iNOS. Similarly, upon LPS stimulation, pretreatment NOB diminished the secretion of the proinflammatory cytokines in BV-2 microglia cells by exposure to LPS via modulating MAPKs, PI3K/AKT, and NF-κB signaling pathways. In addition, NOB alleviated LPS-amplified redox imbalance, disturbance of mitochondrial membrane potential (MMP), and dampening of the expression of protein related to mitochondrial respiration. The present study provides compelling evidence that NOB decreased LPS-stimulated neuroinflammation and memory impairment through maintaining cellular oxidative balance and blocking the NF-κB transcriptional pathway, illustrating that the nutritional compound NOB may serve as a potential approach to alleviate neuroinflammation-related diseases.


Assuntos
Flavonas/administração & dosagem , Inflamação/complicações , Transtornos da Memória/prevenção & controle , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , NF-kappa B/imunologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/imunologia , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/imunologia , Humanos , Inflamação/genética , Inflamação/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Masculino , Transtornos da Memória/etiologia , Transtornos da Memória/genética , Transtornos da Memória/imunologia , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/imunologia , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , NF-kappa B/genética , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
11.
Neurol Sci ; 40(6): 1157-1166, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30830567

RESUMO

BACKGROUND AND PURPOSE: Various types of cerebral small vessel diseases (CSVD) are commonly coexisting and the clinical outcome possibly is determined by their combined effect. The present study was designed to explore the possible relationship between the global burden of CSVD and clinical outcomes after recombinant tissue plasminogen activator (rt-PA) treatment of ischemic stroke. METHODS: We enrolled patients with acute ischemic stroke (AIS) after IV rt-PA treatment between August 2016 and July 2018. According to the total burden rating scale of CSVD, we calculated the total CSVD score for white matter hyperintensities, lacunar infarction, cerebral microbleeds, and perivascular spaces. All patients were assessed on the basis of the National Institutes of Health Stroke Scale (NIHSS) score and the modified Rankin Scale (mRS) score at 90 days after stroke. We used multivariate logistic regression analysis to examine the associations between global burden of CSVD and degree of neurological deficit and clinical outcomes. ROC curve analysis was used to determine cut-off values of the total CSVD score in predicting poor outcomes. RESULTS: The results showed that the total CSVD score was independently associated with moderate to severe stroke (OR 2.187, 95%CI 1.495-3.119, P < 0.001). Initial NIHSS (OR 1.23, 95%CI 1.144-1.330, P < 0.001), OTT (OR 1.007, 95%CI 1.000-1.014, P = 0.037), and CSVD score (OR 3.157, 95%CI 2.120-4.703, P < 0.001) was significantly related to poor functional outcome at 3 months. The total CVSD score cut-off value of 1.5 was determined at best to distinguish between good prognosis and poor outcome (AUC 0.7534 [95%CI 0.6883-0.8185]). CONCLUSIONS: The global burden of CSVD was independently associated with neurological deficit severity and clinical outcomes of AIS after IV rt-PA treatment. The total CVSD score is a reliable predictor for poor outcomes of AIS after IV rt-PA treatment.


Assuntos
Isquemia Encefálica/diagnóstico , Isquemia Encefálica/psicologia , Doenças de Pequenos Vasos Cerebrais/diagnóstico , Doenças de Pequenos Vasos Cerebrais/psicologia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/psicologia , Ativador de Plasminogênio Tecidual/uso terapêutico , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do Tratamento
12.
Exp Neurol ; 313: 16-25, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30529503

RESUMO

Intracerebral hemorrhage (ICH) is a common and severe neurological disorder, which is associated with high rates of mortality and morbidity. This study aimed to evaluate whether general control non-derepressible-2 (GCN2) stimulation ameliorated neuroinflammation after ICH. Male CD-1 mice were subjected to experimental ICH by infusion of bacterial collagenase. Post-ictus assessment included neurobehavioral tests, brain edema measurement, quantification of neutrophil infiltration and microglia activation, and measurement of TNF-α and IL-1ß expression at 24h after ICH. Furthermore, we tested the long-term neurological improvement by GCN2 at 21 days after ICH. Our results showed that GCN2 improved neurological function and reduced brain edema at 24 and 72 h following experimental ICH in CD-1 mice in contrast to the vehicle administration alone. GCN2 was also found to decrease levels of IL-1ß and TNF-α, and inhibit neutrophil infiltration activation. In addititon, GCN2 also alleviated long-term neurological impairment after ICH. However, inhibition of eIF2α or ATF4 abolished the protective effects of GCN2, indicating eIF2α/ATF4 signaling pathway as the downstream mediator of GCN2.


Assuntos
Fator 4 Ativador da Transcrição/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Hemorragia Cerebral/complicações , Fator de Iniciação 2 em Eucariotos/efeitos dos fármacos , Inflamação/etiologia , Inflamação/prevenção & controle , Proteínas Serina-Treonina Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator 4 Ativador da Transcrição/biossíntese , Animais , Comportamento Animal , Edema Encefálico/etiologia , Edema Encefálico/prevenção & controle , Hemorragia Cerebral/psicologia , Citocinas/biossíntese , Fator de Iniciação 2 em Eucariotos/biossíntese , Inflamassomos/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Infiltração de Neutrófilos/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
13.
Food Chem Toxicol ; 122: 181-193, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30316844

RESUMO

Circadian rhythms are intimately linked to cellular redox status homeostasis via the regulation of mitochondrial function. Tea polyphenols (TP) are nutraceuticals that possess powerful antioxidant properties, especially ameliorating oxidative stress. The objective of this study was to investigate whether circadian clock is involved in the protection effect of TP on oxidative stress cell models. TP ameliorate H2O2-triggered relatively shallow daily oscillations and phase shift of circadian clock genes transcription and protein expression. Meanwhile, TP attenuate H2O2-stimulated excessive secretions of reactive oxygen species (ROS) and restore the depletions of mitochondrial function in a Bmal1-dependent manner. Furthermore, TP treatment accelerates nuclear translocation of Nrf2 and modulates the downstream expressions of antioxidant enzymes. Intriguingly, knockdown of Bmal1 notably blocked Nrf2/ARE/HO-1 redox-sensitive transcription pathway. Our study revealed that TP, as a Bmal1-enhancing natural compound, alleviated redox imbalance via strengthening Keap1/Nrf2 antioxidant defense pathway and ameliorating mitochondrial dysfunction in a Bmal1-dependent manner.


Assuntos
Fatores de Transcrição ARNTL/efeitos dos fármacos , Relógios Circadianos , Hepatócitos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Polifenóis/farmacologia , Chá/química , Fatores de Transcrição ARNTL/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas CLOCK/genética , Ritmo Circadiano , Heme Oxigenase-1/metabolismo , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
14.
Food Funct ; 9(3): 1510-1523, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29423494

RESUMO

As a major nutraceutical component of green tea (-)-epigallocatechin-3-gallate (EGCG) has attracted interest from scientists due to its well-documented antioxidant and antiobesity bioactivities. In the current study, we aimed to investigate the protective effect of EGCG on metabolic misalignment and in balancing the redox status in mice liver and HepG2 cells under insulin resistance condition. Our results indicated that EGCG accelerates the glucose uptake and evokes IRS-1/Akt/GLUT2 signaling pathway via dampening the expression of protein tyrosine phosphatase 1B (PTP1B). Consistently, ectopic expression of PTP1B by Ad-PTP1B substantially impaired EGCG-elicited IRS-1/Akt/GLUT2 signaling pathway. Moreover, EGCG co-treatment stimulated nuclear translocation of Nrf2 by provoking P13K/AKT signaling pathway and thus modulated the downstream expressions of antioxidant enzymes such as HO-1 and NQO-1 in HepG2 cells. Furthermore, knockdown Nrf2 by small interfering RNA (siRNA) notably enhanced the expression of PTP1B and blunt EGCG-stimulated glucose uptake. Consistent with these results, in vivo study revealed that EGCG supplement significantly ameliorated high-fat and high-fructose diet (HFFD)-triggered insulin resistance and oxidative stress by up-regulating the IRS-1/AKT and Keap1/Nrf2 transcriptional pathways. Administration of an appropriate chemopreventive agent, such as EGCG, could potentially serve as an additional therapeutic intervention in the arsenal against obesity.


Assuntos
Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Catequina/análogos & derivados , Resistência à Insulina , Fator 2 Relacionado a NF-E2/metabolismo , Obesidade/tratamento farmacológico , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética , Animais , Catequina/farmacologia , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Humanos , Insulina/metabolismo , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Obesidade/genética , Obesidade/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
Food Funct ; 8(12): 4421-4432, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29090295

RESUMO

Many studies have shown that oxidative stress is a major cause of cellular injuries in a variety of human diseases including cognitive impairment. Tea polyphenols (TPs), natural plant flavonoids found in tea plant leaves, possess the bioactivity to affect the pathogenesis of several chronic diseases via antioxidant associated mechanisms. However, the possible antioxidant and neuroprotective properties of TPs in the brain of mice housed in constant darkness and in H2O2-stimulated SH-SY5Y cells are yet to be elucidated. In this study, pretreatment with TPs markedly attenuated H2O2-elicited cell viability loss and mitochondrial dysfunction, suppressed the induced apoptosis and reduced the elevated levels of intracellular ROS and H2O2. Additionally, TPs modulate the nuclear translocation of Nrf2 and the TrkB/CREB/BDNF signaling pathway by provoking the PI3K/AKT pathway and thus, they transcriptionally regulate the downstream expression of antioxidant enzymes including HO-1, NQO-1, and BDNF in SH-SY5Y cells. Furthermore, an in vivo study revealed that housing mice in constant darkness, simulating shift work disruption in humans, notably affects the AKT/CREB/BDNF signal pathway and the nuclear translocation of Nrf2 and its downstream phase II detoxification enzymes in brain tissue. Remarkably, TP supplementation through drinking water eliminated these changes. These results suggest that TPs possess protective effects against oxidative stress-triggered cognitive impairment, which might be a potential nutritional preventive strategy for neurodegenerative diseases implicated with oxidative stress in shift workers.


Assuntos
Encéfalo/efeitos dos fármacos , Proteína de Ligação a CREB/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Receptor trkB/metabolismo , Animais , Apoptose/efeitos dos fármacos , Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína de Ligação a CREB/genética , Camellia sinensis/química , Sobrevivência Celular/efeitos dos fármacos , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Receptor trkB/genética , Transdução de Sinais/efeitos dos fármacos
16.
Mol Nutr Food Res ; 61(12)2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28869341

RESUMO

SCOPE: Normal physiological processes require a robust biological timer called the circadian clock. Dysregulation of circadian rhythms contributes to a variety of metabolic syndrome, including obesity and insulin resistance. (-)-Epigallocatechin-3-gallate (EGCG) has been demonstrated to possess antioxidant, anti-inflammatory, and cardioprotective bioactivities. The objective of this study was to explore whether the circadian clock is involved in the protective effect of EGCG against insulin resistance. METHODS AND RESULTS: The results demonstrated that EGCG reverses the relatively shallow daily oscillations of circadian clock genes transcription and protein expression induced by glucosamine in HepG2 cells. EGCG also alleviates insulin resistance by enhancing tyrosine phosphorylated levels of IRS-1, stimulating the translocation of GLUT2, and activating PI3K/AKT as well as AMPK signaling pathways in a Bmal1-dependent manner both in HepG2 cells and primary hepatocytes. Glucosamine-stimulated excessive secretions of ROS and depletions of mitochondrial membrane potential were notably attenuated in EGCG co-treated HepG2 cells, which consistent with the recovery in expression of mitochondrial respiration complexes. CONCLUSION: The results demonstrated that EGCG possesses a Bmal1-dependent efficacy against insulin resistance conditions by strengthening the insulin signaling and eliminating oxidative stress, suggesting that EGCG may serve as a promising natural nutraceutical for the regulation of metabolic disorders relevant to circadian clocks.


Assuntos
Fatores de Transcrição ARNTL/metabolismo , Catequina/análogos & derivados , Hepatócitos/efeitos dos fármacos , Resistência à Insulina , Mitocôndrias Hepáticas/efeitos dos fármacos , Proteínas Quinases Ativadas por AMP/metabolismo , Fatores de Transcrição ARNTL/genética , Animais , Catequina/farmacologia , Células Cultivadas , Relógios Circadianos/efeitos dos fármacos , Glucosamina/farmacologia , Glucose/metabolismo , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Resistência à Insulina/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos
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