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1.
Environ Toxicol ; 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654489

RESUMO

Lipotoxicity leads to numerous metabolic disorders such as nonalcoholic steatohepatitis. Luteolin, apigenin, and chrysin are three flavones with known antioxidant and anti-inflammatory properties, but whether they inhibit lipotoxicity-mediated NLRP3 inflammasome activation was unclear. To address this question, we used J774A.1 macrophages and Kupffer cells stimulated with 100 µM palmitate (PA) in the presence or absence of 20 µM of each flavone. PA increased p-PERK, p-IRE1α, p-JNK1/2, CHOP, and TXNIP as well as p62 and LC3-II expression and induced autophagic flux damage. Caspase-1 activation and IL-1ß release were also noted after 24 h of exposure to PA. In the presence of the PERK inhibitor GSK2656157, PA-induced CHOP and TXNIP expression and caspase-1 activation were mitigated. Compared with PA treatment alone, Bcl-2 coupled to beclin-1 was elevated and autophagy was reversed by the JNK inhibitor SP600125. With luteolin, apigenin, and chrysin treatment, PA-induced ROS production, ER stress, TXNIP expression, autophagic flux damage, and apoptosis were ameliorated. Moreover, TXNIP binding to NLRP3 and IL-1ß release in response to LPS/PA challenge were reduced. These results suggest that luteolin, apigenin, and chrysin protect hepatic macrophages against PA-induced NLRP3 inflammasome activation and autophagy damage by attenuating endoplasmic reticulum stress.

3.
Toxicol Appl Pharmacol ; 462: 116424, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36775252

RESUMO

The NLRP3 inflammasome plays an important role in the pathogenesis of numerous inflammation-related diseases. Benzyl isothiocyanate (BITC) is rich in cruciferous vegetables and possesses potent antioxidant, anti-inflammatory, anti-cancer, and anti-obesogenic properties. In this study, we investigated the role of the NLRP3 inflammasome in the protection by BITC against steatohepatitis and insulin resistance. A mouse model of high-fat/cholesterol/cholic acid diet (HFCCD)-induced steatohepatitis, LPS/nigericin-stimulated primary Kupffer cells, and IL-1ß treated primary hepatocytes were used. BITC attenuated LPS/nigericin-induced activation of the NLRP3 inflammasome by enhancing protein kinase A-dependent NLRP3 ubiquitination, which increased the degradation of NLRP3 and reduced IL-1ß secretion in Kupffer cells. In hepatocytes, BITC pretreatment reversed the IL-1ß-induced decrease in the phosphorylation of IR, AKT, and GSK3ß in response to insulin. After 12 weeks of HFCCD feeding, increases in blood alanine aminotransferase (ALT) and glucose levels were ameliorated by BITC. Hepatic IL-1ß production, macrophage infiltration, and collagen expression induced by HFCCD were also mitigated by BITC. BITC suppresses activation of the NLRP3 inflammasome in Kupffer cells by enhancing the PKA-dependent ubiquitination of NLRP3, which leads to suppression of IL-1ß production and subsequently ameliorates hepatic inflammation and insulin resistance.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Inflamassomos/metabolismo , Células de Kupffer , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Nigericina/metabolismo , Lipopolissacarídeos/farmacologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Colesterol/metabolismo , Dieta Hiperlipídica , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Camundongos Endogâmicos C57BL
4.
Toxicol Appl Pharmacol ; 410: 115341, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33242555

RESUMO

Andrographolide (AND) is the major diterpenoid in A. paniculata with wide clinical application and has been shown to be a potent anti-inflammatory agent. Gout is the leading inflammatory disease of the joints, and the deposition of urate in the articular cavity attracts immune cells that release inflammatory cytokines. Monosodium urate (MSU) is known to be one of the activators of the NLRP3 (NLR family pyrin domain containing 3) inflammasome. After activation, the NLRP3 inflammasome releases interleukin-1ß (IL-1ß), which causes the development of many inflammatory diseases. The aim of the present study was to investigate whether AND attenuates the release of IL-1ß mediated by the NLRP3 inflammasome. The effects of AND were studied in bone marrow-derived macrophages (BMDMs) treated with lipopolysaccharide (LPS) and MSU and in mice with MSU-induced joint inflammation. AND suppressed MSU phagocytosis dose-dependently and markedly inhibited LPS- and MSU-induced IL-1ß release in BMDMs. Moreover, AND pretreatment inhibited the LPS-induced NLRP3 inflammasome priming stage by inhibiting the IKK/NFκB signaling pathway, which resulted in decreased protein expression of NLRP3 and proIL-1ß. AND induced HO-1 protein expression in a dose-dependent manner and attenuated MSU-induced ROS generation. Silencing HO-1 mitigated AND inhibition of LPS/MSU-induced IL-1ß release in J774A.1 cells. In addition, AND decreased MSU-mediated ASC binding to NLRP3. Oral administration of AND attenuated MSU-induced monocyte infiltration in mouse knee joints. These results suggest that the working mechanisms by which AND down-regulates MSU-induced joint inflammation might be via HO-1 induction and attenuation of ROS-mediated NLRP3 inflammasome assembly and subsequent IL-1ß release.


Assuntos
Diterpenos/farmacologia , Interleucina-1beta/antagonistas & inibidores , Articulação do Joelho/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Ácido Úrico/toxicidade , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/toxicidade , Linhagem Celular , Células Cultivadas , Humanos , Interleucina-1beta/metabolismo , Articulação do Joelho/metabolismo , Articulação do Joelho/patologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/metabolismo
5.
Toxicol Appl Pharmacol ; 393: 114941, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32126212

RESUMO

Incidence of nonalcoholic fatty liver disease is increasing worldwide. Activation of the NLRP3 inflammasome is central to the development of diet-induced nonalcoholic steatohepatitis (NASH). We investigated whether benzyl isothiocyanate (BITC) ameliorates diet-induced NASH and the mechanisms involved. C57BL/6 J mice fed a high-fat diet containing cholesterol and cholic acid (HFCCD) and Kupffer cells stimulated with LPS and cholesterol crystals (CC) were studied. LPS/CC increased the expression of the active form of caspase 1 (p20) and the secretion of IL-1ß by Kupffer cells, and these changes were reversed by MCC950, an NLRP3 inflammasome inhibitor. LPS/CC-induced NLRP3 inflammasome activation and IL-1ß production were dose-dependently attenuated by BITC. BITC decreased cathepsin B release from lysosomes and binding to NLRP3 induced by LPS/CC. Compared with a normal diet, the HFCCD increased serum levels of ALT, AST, total cholesterol, and IL-1ß and hepatic contents of triglycerides and total cholesterol. BITC administration (0.1% in diet) reversed the increase in AST and hepatic triglycerides in the HFCCD group. Moreover, BITC suppressed lipid accumulation, macrophage infiltration, fibrosis, crown-like structure formation, and p20 caspase 1 and p17 IL-1ß expression in liver in the HFCCD group. These results suggest that BITC ameliorates HFCCD-induced steatohepatitis by inhibiting the activation of NLRP3 inflammasome in Kupffer cells and may protect against diet-induced NASH.


Assuntos
Colesterol na Dieta/efeitos adversos , Colesterol/química , Ácido Cólico/efeitos adversos , Dieta Hiperlipídica/efeitos adversos , Inflamassomos/efeitos dos fármacos , Isotiocianatos/uso terapêutico , Células de Kupffer/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Colesterol/sangue , Relação Dose-Resposta a Droga , Interleucina-1beta/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Testes de Função Hepática , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/etiologia , Triglicerídeos/metabolismo
6.
Langmuir ; 31(22): 6130-6, 2015 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-25985827

RESUMO

Polyethylenimine (PEI) and poly(2-(dimethylamino) ethyl methacrylate) (PDMAEMA) have both been used for DNA delivery. PDMAEMA has been shown to exhibit better gene transfection efficiency but lower expression ability than PEI. We mixed the two polymers at different ratios to investigate whether the resulting "dual" polyplex (PEI/PDMAEMA/DNA) could enhance both gene transfection efficiency and DNA expression ability. Experimental results showed a significant increase in DNA internalization and DNA expression for the PDMAEMA/PEI/DNA polyplexes at a ratio of 1:3 or 1:9 (PDMAEMA: PEI), depending on cell type, in comparison with PEI/DNA, PDMAEMA/DNA, and PDMAEMA/PEI/DNA at other ratios. PDMAEMA/PEI/DNA polyplexes did not reduce cell viability. In contrast to with the conventional approach using covalently modified PEI, the proposed "combination" approach provided a more convenient and effective way to improve transgene expression efficiency.


Assuntos
DNA/genética , Técnicas de Transferência de Genes , Metacrilatos/química , Nylons/química , Polietilenoimina/química , Transgenes/genética , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Metacrilatos/farmacologia , Camundongos , Estrutura Molecular , Células NIH 3T3 , Nylons/farmacologia , Polietilenoimina/farmacologia , Regiões Promotoras Genéticas/genética
7.
Langmuir ; 30(19): 5510-7, 2014 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-24754730

RESUMO

Specific drug delivery to solid tumors remains one of the challenges in cancer therapy. The aim of this study was to combine three drug-targeting strategies, polymer-drug conjugate, ligand presentation and ultrasound treatment, to enhance the efficacy and selectivity of doxorubicin (DXR) to hepatoma cells. The conjugation of DXR to γ-poly(glutamic acids) (γ-PGA) decreased the cytotoxicity of DXR, while the conjugation of galactosamine (Gal) to the γ-PGA-DXR conjugate restored the cytotoxic efficacy of DXR on hepatoma cells due to increased uptake of DXR. Furthermore, low-intensity ultrasound treatment increased the cell-killing ability of γ-PGA-DXR conjugates by 20%. The in vitro results showed the potential of the γ-PGA-DXR-Gal conjugate for future clinical applications.


Assuntos
Doxorrubicina/química , Doxorrubicina/farmacologia , Galactose/química , Nanopartículas/química , Ultrassom , Carcinoma Hepatocelular , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Humanos , Células Tumorais Cultivadas
8.
Pharm Res ; 31(9): 2354-66, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24623478

RESUMO

PURPOSE: Polyethylenimine (PEI), a cationic polymer, has been shown to aggregate plasmid DNA and facilitate its internalization. It has also been shown that combining ultrasound (US) with PEI could enhance and prolong in vitro and in vivo transgene expression. However, the role US in the enhancement of PEI uptake is poorly understood. This study investigates the impact of US on PEI-mediated gene transfection. METHODS: Specific endocytosis pathway siRNA, including clathrin HC siRNA, caveolin-1 siRNA and protein kinase C-delta (PKC-δ) siRNA, are used to block the corresponding endocytosis pathways prior to the transfection of luciferase DNA/PEI polyplexes to cultured cells by 1-MHz pulsed US with ultrasound contrast agent SonoVue®. RESULTS: Transgene expression was found not to be enhanced by US treatment in the presence of the PKC-δ siRNA. We further demonstrated that PKC-δ protein could be enhanced at 6 h after US exposure. Moreover, intracellular calcium levels were found to be significantly increased at 3 h after US exposure, while transgene expressions were significantly reduced in the presence of calcium channel blockers both in vitro and in vivo. CONCLUSIONS: Our results suggest that US enhanced PEI-mediated gene transfection specifically by increasing PKC-δ related fluid phase endocytosis, which was induced by increasing the intracellular calcium levels.


Assuntos
DNA/administração & dosagem , Endocitose , Polietilenoimina/metabolismo , Proteína Quinase C-delta/genética , Transfecção/métodos , Ultrassom , Animais , Cálcio/metabolismo , Linhagem Celular , DNA/genética , Vaga-Lumes/enzimologia , Vaga-Lumes/genética , Humanos , Luciferases de Vaga-Lume/genética , Camundongos , Camundongos Endogâmicos BALB C , Proteína Quinase C-delta/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética
9.
PLoS One ; 19(6): e0305333, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38889141

RESUMO

Language is rooted in our ability to compose: We link words together, fusing their meanings. Links are not limited to neighboring words but often span intervening words. The ability to process these non-adjacent dependencies (NADs) conflicts with the brain's sampling of speech: We consume speech in chunks that are limited in time, containing only a limited number of words. It is unknown how we link words together that belong to separate chunks. Here, we report that we cannot-at least not so well. In our electroencephalography (EEG) study, 37 human listeners learned chunks and dependencies from an artificial grammar (AG) composed of syllables. Multi-syllable chunks to be learned were equal-sized, allowing us to employ a frequency-tagging approach. On top of chunks, syllable streams contained NADs that were either confined to a single chunk or crossed a chunk boundary. Frequency analyses of the EEG revealed a spectral peak at the chunk rate, showing that participants learned the chunks. NADs that cross boundaries were associated with smaller electrophysiological responses than within-chunk NADs. This shows that NADs are processed readily when they are confined to the same chunk, but not as well when crossing a chunk boundary. Our findings help to reconcile the classical notion that language is processed incrementally with recent evidence for discrete perceptual sampling of speech. This has implications for language acquisition and processing as well as for the general view of syntax in human language.


Assuntos
Eletroencefalografia , Idioma , Humanos , Feminino , Masculino , Adulto , Adulto Jovem , Percepção da Fala/fisiologia , Fala/fisiologia , Aprendizagem/fisiologia , Encéfalo/fisiologia
10.
Nutr Res ; 121: 95-107, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38056034

RESUMO

Tumor necrosis factor α (TNFα), an inflammatory cytokine, induces lipolysis and increases circulating concentrations of free fatty acids. In addition, TNFα is the first adipokine produced by adipose tissue in obesity, contributing to obesity-associated metabolic disease. Given that benzyl isothiocyanate (BITC) is a well-known anti-inflammatory agent, we hypothesized that BITC can ameliorate TNFα-induced lipolysis and investigated the working mechanisms involved. We first challenged 3T3-L1 adipocytes with TNFα to induce lipolysis, which was confirmed by increased glycerol release, decreased protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and perilipin 1 (PLIN1), and increased phosphorylation of ERK, protein kinase A (PKA), and hormone-sensitive lipase (HSL). However, inhibition of ERK or PKA significantly attenuated the lipolytic activity of TNFα. Meanwhile, pretreatment with BITC significantly ameliorated the lipolytic activity of TNFα; the TNFα-induced phosphorylation of ERK, PKA, and HSL; the TNFα-induced ubiquitination of PPARγ; the TNFα-induced decrease in PPARγ nuclear protein binding to PPAR response element; and the TNFα-induced decrease in PLIN1 protein expression. Our results indicate that BITC ameliorates TNFα-induced lipolysis by inhibiting the ERK/PKA/HSL signaling pathway, preventing PPARγ proteasomal degradation, and maintaining PLIN1 protein expression.


Assuntos
Esterol Esterase , Fator de Necrose Tumoral alfa , Animais , Camundongos , Fator de Necrose Tumoral alfa/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Esterol Esterase/metabolismo , Lipólise , Células 3T3-L1 , PPAR gama/metabolismo , Transdução de Sinais , Fosforilação , Adipócitos/metabolismo , Obesidade/metabolismo , Perilipina-1/metabolismo
11.
Sci Rep ; 13(1): 18522, 2023 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-37898645

RESUMO

Memory is fleeting. To avoid information loss, humans need to recode verbal stimuli into chunks of limited duration, each containing multiple words. Chunk duration may also be limited neurally by the wavelength of periodic brain activity, so-called neural oscillations. While both cognitive and neural constraints predict some degree of behavioral regularity in processing, this remains to be shown. Our analysis of self-paced reading data from 181 participants reveals periodic patterns at a frequency of [Formula: see text] 2 Hz. We defined multi-word chunks by using a computational formalization based on dependency annotations and part-of-speech tags. Potential chunk outputs were first generated from the computational formalization and the final chunk outputs were selected based on normalized pointwise mutual information. We show that behavioral periodicity is time-aligned to multi-word chunks, suggesting that the multi-word chunks generated from local dependency clusters may minimize memory demands. This is the first evidence that sentence processing behavior is periodic, consistent with a role of both memory constraints and endogenous electrophysiological rhythms in the formation of chunks during language comprehension.


Assuntos
Idioma , Memória , Humanos , Periodicidade
12.
Food Chem Toxicol ; 171: 113554, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36509263

RESUMO

Abnormal accumulation of lipids in liver leads to uncontrolled endoplasmic reticulum (ER) stress and autophagy. Luteolin is known to have antioxidant, anti-inflammatory, and anti-cancer properties, but whether it protects against lipotoxicity in liver remains unclear. In this study, we challenged AML12 liver cells and mouse primary hepatocytes with palmitic acid (PA) with or without luteolin pretreatment. In the presence of PA, reactive oxygen species (ROS) production was increased at 3 h, followed by enhancement of expression of p-PERK, ATF4, p-eIF2α, CHOP, and TXNIP (ER stress markers) and p-p62 and LC3II/LC3I ratio (autophagy markers), in both primary hepatocytes and AML12 cells. When PA treatment was extended up to 24 h, apoptosis was induced as evidenced by an increase in caspase-3 activation. RFP-GFP-LC3B transfection further revealed that the fusion of autophagosomes with lysosomes was damaged by PA. With luteolin treatment, the expression of antioxidant enzymes, i.e., heme oxygenase-1 and glutathione peroxidase, was upregulated, and PA-induced ROS production, ER stress, and cell death were dose-dependently ameliorated. Luteolin could also reverse the damage caused to autophagic flux. These results indicate that luteolin protects hepatocytes against PA assault by enhancing antioxidant defense, which can attenuate ER stress and autophagy as well as promote autophagic flux.


Assuntos
Luteolina , Palmitatos , Camundongos , Animais , Luteolina/metabolismo , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Hepatócitos/metabolismo , Estresse do Retículo Endoplasmático , Ácido Palmítico/farmacologia , Autofagia , Apoptose
13.
Am J Chin Med ; 51(8): 2175-2193, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37930331

RESUMO

Andrographolide (AND) is a bioactive component of the herb Andrographis paniculata and a well-known anti-inflammatory agent. Atherosclerosis is a chronic inflammatory disease of the vasculature, and oxidized LDL (oxLDL) is thought to contribute heavily to atherosclerosis-associated inflammation. The aim of this study was to investigate whether AND mitigates oxLDL-mediated foam cell formation and diet-induced atherosclerosis (in mice fed a high-fat, high-cholesterol, high-cholic acid [HFCCD] diet) and the underlying mechanisms involved. AND attenuated LPS/oxLDL-mediated foam cell formation, IL-1[Formula: see text] mRNA and protein (p37) expression, NLR family pyrin domain containing 3 (NLRP3) mRNA and protein expression, caspase-1 (p20) protein expression, and IL-1[Formula: see text] release in BMDMs. Treatment with oxLDL significantly induced protein and mRNA expression of CD36, lectin-like oxLDL receptor-1 (LOX-1), and scavenger receptor type A (SR-A), whereas pretreatment with AND significantly inhibited protein and mRNA expression of SR-A only. Treatment with oxLDL significantly induced ROS generation and Dil-oxLDL uptake; however, pretreatment with AND alleviated oxLDL-induced ROS generation and Dil-oxLDL uptake. HFCCD feeding significantly increased aortic lipid accumulation, ICAM-1 expression, and IL-1[Formula: see text] mRNA expression, as well as blood levels of glutamic pyruvic transaminase (GPT), total cholesterol, and LDL-C. AND co-administration mitigated aortic lipid accumulation, the protein expression of ICAM-1, mRNA expression of IL-1[Formula: see text] and ICAM-1, and blood levels of GPT. These results suggest that the working mechanisms by which AND mitigates atherosclerosis involve the inhibition of foam cell formation and NLRP3 inflammasome-dependent vascular inflammation as evidenced by decreased SR-A expression and IL-1[Formula: see text] release, respectively.


Assuntos
Aterosclerose , Inflamassomos , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/metabolismo , Lipoproteínas LDL , Células Espumosas/metabolismo , Receptores Depuradores , Inflamação/metabolismo , Colesterol/metabolismo , Aterosclerose/tratamento farmacológico , Aterosclerose/etiologia , Aterosclerose/metabolismo , RNA Mensageiro/metabolismo , Interleucina-1/metabolismo
14.
Am J Chin Med ; 51(1): 129-147, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36419253

RESUMO

Andrographolide is the major bioactive component of the herb Andrographis paniculata and is a potent anti-inflammatory agent. Obesity leads to an excess of free fatty acids, particularly palmitic acid (PA), in the circulation. Obesity also causes the deposition of ectopic fat in nonadipose tissues, which leads to lipotoxicity, a condition closely associated with inflammation. Here, we investigated whether andrographolide could inhibit PA-induced inflammation by activating autophagy, activating the antioxidant defense system, and blocking the activation of the NLRP3 inflammasome. Bone marrow-derived macrophages (BMDMs) were primed with lipopolysaccharide (LPS) and then activated with PA. LPS/PA treatment increased both the mRNA expression of NLRP3 and IL-1[Formula: see text] and the release of IL-1[Formula: see text] in BMDMs. Andrographolide inhibited the LPS/PA-induced protein expression of caspase-1 and the release of IL-1[Formula: see text]. Furthermore, andrographolide attenuated LPS/PA-induced mtROS generation by first promoting autophagic flux and catalase activity, and ultimately inhibiting activation of the NLRP3 inflammasome. Our results suggest that the mechanisms by which andrographolide downregulates LPS/PA-induced IL-1[Formula: see text] release in BMDMs involve promoting autophagic flux and catalase activity. Andrographolide may thus be a candidate to prevent obesity- and lipotoxicity-driven chronic inflammatory disease.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Lipopolissacarídeos/efeitos adversos , Catalase/metabolismo , Macrófagos/metabolismo , Inflamação/metabolismo , Antioxidantes/metabolismo , Interleucina-1/metabolismo , Camundongos Endogâmicos C57BL
15.
Neurobiol Lang (Camb) ; 3(4): 538-555, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37215342

RESUMO

Neural responses appear to synchronize with sentence structure. However, researchers have debated whether this response in the delta band (0.5-3 Hz) really reflects hierarchical information or simply lexical regularities. Computational simulations in which sentences are represented simply as sequences of high-dimensional numeric vectors that encode lexical information seem to give rise to power spectra similar to those observed for sentence synchronization, suggesting that sentence-level cortical tracking findings may reflect sequential lexical or part-of-speech information, and not necessarily hierarchical syntactic information. Using electroencephalography (EEG) data and the frequency-tagging paradigm, we develop a novel experimental condition to tease apart the predictions of the lexical and the hierarchical accounts of the attested low-frequency synchronization. Under a lexical model, synchronization should be observed even when words are reversed within their phrases (e.g., "sheep white grass eat" instead of "white sheep eat grass"), because the same lexical items are preserved at the same regular intervals. Critically, such stimuli are not syntactically well-formed; thus a hierarchical model does not predict synchronization of phrase- and sentence-level structure in the reversed phrase condition. Computational simulations confirm these diverging predictions. EEG data from N = 31 native speakers of Mandarin show robust delta synchronization to syntactically well-formed isochronous speech. Importantly, no such pattern is observed for reversed phrases, consistent with the hierarchical, but not the lexical, accounts.

16.
Chin J Physiol ; 54(2): 87-95, 2011 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-21789889

RESUMO

Exercise can ameliorate vascular dysfunction in hypertension, but its underlying mechanism has not been explored thoroughly. We aimed to investigate whether the high-intensity exercise could enhance vasorelaxation mediated by insulin and insulin-like growth factor-1 (IGF-1) in hypertension. Sixteen-week-old spontaneously hypertensive rats were randomly divided into non-exercise sedentary (SHR) and high-intensity exercise (SHR+Ex) groups conducted by treadmill running at a speed of 30 m/ min until exhaustion. Age-matched Wistar-Kyoto rats (WKY) were used as the normotensive control group. Immediately after exercise, the agonist-induced vasorelaxation of aortas was evaluated in organ baths with or without endothelial denudation. Selective inhibitors were used to examine the roles of nitric oxide synthase (NOS) and phosphatidylinositol-3 kinase (PI3K) in the vasorelaxation. By adding superoxide dismutase (SOD), a superoxide scavenger, the role of superoxide production in the vasorelaxation was also clarified. We found that, the high-intensity exercise significantly (P < 0.05) induced higher vasorelaxant responses to insulin and IGF-1 in the SHR+Ex group than that in the SHR group; after endothelial denudation and pre-treatment of the PI3K inhibitor, NOS inhibitor, or SOD, vasorelaxant responses to insulin and IGF-1 became similar among three groups; the protein expression of insulin receptor, IGF-1 receptor, and endothelial NOS (eNOS) was significantly (P < 0.05) increased in the SHR+Ex group compared with the SHR group;] the relaxation to sodium nitroprusside, a NO donor, was not different among three groups. Our findings suggested that the high-intensity exercise ameliorated the insulin- and IGF-1-mediated vasorelaxation through the endothelium-dependent pathway, which was associated with the reduced level of superoxide production.


Assuntos
Hipertensão/fisiopatologia , Condicionamento Físico Animal/fisiologia , Vasodilatação/fisiologia , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiologia , Hipertensão/metabolismo , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Masculino , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo III/metabolismo , Nitroprussiato/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Superóxidos/metabolismo , Vasodilatação/efeitos dos fármacos
17.
Front Hum Neurosci ; 15: 591613, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33613208

RESUMO

Event-related potential components are sensitive to the processes underlying how questions are understood. We use so-called "covert" wh-questions in Mandarin to probe how such components generalize across different kinds of constructions. This study shows that covert Mandarin wh-questions do not elicit anterior negativities associated with memory maintenance, even when such a dependency is unambiguously cued. N = 37 native speakers of Mandarin Chinese read Chinese questions and declarative sentences word-by-word during EEG recording. In contrast to prior studies, no sustained anterior negativity (SAN) was observed between the cue word, such as the question-embedding verb "wonder," and the in-situ wh-filler. SANs have been linked with working memory maintenance, suggesting that grammatical features may not impose the same maintenance demands as the content words used in prior work.

18.
Am J Chin Med ; 49(6): 1473-1491, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34240660

RESUMO

14-Deoxy-11,12-didehydroandrographolide (deAND), a bioactive component of Andrographis paniculata, has antidiabetic activity. AMP-activated protein kinase (AMPK) regulates glucose transport and ameliorates insulin resistance. The aim of the present study was to investigate whether activation of AMPK is involved in the mechanism by which deAND ameliorates insulin resistance in muscles. deAND amounts up to 40 [Formula: see text]M dose-dependently activated phosphorylation of AMPK[Formula: see text] and TBC1D1 in C2C12 myotubes. In addition, deAND significantly activated phosphorylation of LKB1 at 6 h after treatment, and this activation was maintained up to 48 h. deAND increased glucose uptake at 18 h after treatment, and this increase was time dependent up to 72 h. Compound C, an inhibitor of AMPK, suppressed deAND-induced phosphorylation of AMPK[Formula: see text] and TBC1D1 and reversed the effect on glucose uptake. In addition, the expression of GLUT4 mRNA and protein in C2C12 myotubes was up-regulated by deAND in a time-dependent manner. Promotion of GLUT4 gene transcription was verified by a pGL3-GLUT4 (837 bp) reporter assay. deAND also increased the nuclear translocation of MEF-2A and PPAR[Formula: see text]. After 16 weeks of feeding, the high-fat diet (HFD) inhibited phosphorylation of AMPK[Formula: see text] and TBC1D1 in skeletal muscle of obese C57BL/6JNarl mice, and deactivation of AMPK[Formula: see text] and TBC1D1 by the HFD was abolished by deAND supplementation. Supplementation with deAND significantly promoted membrane translocation of GLUT4 compared with the HFD group. Supplementation also significantly increased GLUT4 mRNA and protein expression in skeletal muscle compared with the HFD group. The hypoglycemic effects of deAND are likely associated with activation of the LKB1/AMPK[Formula: see text]/TBC1D1/GLUT4 signaling pathway and stimulation of MEF-2A- and PPAR[Formula: see text]-dependent GLUT4 gene expression, which account for the glucose uptake into skeletal muscle and lower blood glucose levels.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Diterpenos/farmacologia , Proteínas Ativadoras de GTPase/metabolismo , Intolerância à Glucose/tratamento farmacológico , Transportador de Glucose Tipo 4/efeitos dos fármacos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos
19.
Exp Physiol ; 95(5): 622-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20139168

RESUMO

Limited information is available concerning the effects of aerobic exercise on vasorelaxation in hypertension. The aim of this study was to investigate the effects of a single bout of aerobic exercise on insulin- and insulin-like growth factor-1 (IGF-1)-induced vasorelaxation in hypertensive rats. Four-month-old spontaneously hypertensive rats were randomly divided into a sedentary group (SHR) and an exercise group (SHR+Ex) subjected to a single bout of aerobic exercise conducted by treadmill running at 21 m min(1) for 1 h. Age-matched Wistar-Kyoto rats were used as a normotensive control group (WKY). Insulin- and IGF-1-induced vasorelaxant responses in the three groups were evaluated by using isolated aortic rings, with or without endothelial denudation, in organ baths. Possible roles of phosphatidylinositol 3-kinase (PI3K) and nitric oxide synthase (NOS) involved in the NO-dependent vasorelaxation were examined by adding selective inhibitors. The role of superoxide was also clarified by adding superoxide dismutase (SOD). In addition, the endothelium-independent vascular responses to sodium nitroprusside (SNP), a NO donor, were examined. The insulin- and IGF-1-induced vasorelaxation was significantly (P < 0.05) decreased in the SHR group compared with the WKY group. This decreased response in SHR was improved by exercise. These vasorelaxant responses among the three groups became similar after endothelial denudation and pretreatment with the PI3K inhibitor, NOS inhibitor or SOD. Also, no difference among groups was found in the SNP-induced vasorelaxation. We concluded that a single bout of aerobic exercise acutely improves insulin- and IGF-1-mediated vasorelaxation in an endothelium-dependent manner in hypertensive rats.


Assuntos
Hipertensão/fisiopatologia , Fator de Crescimento Insulin-Like I/farmacologia , Insulina/farmacologia , Condicionamento Físico Animal , Vasodilatação/fisiologia , Androstadienos/farmacologia , Animais , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Nitroprussiato/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Superóxido Dismutase/metabolismo , Vasodilatação/efeitos dos fármacos , Wortmanina
20.
J Agric Food Chem ; 67(25): 7136-7146, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31240929

RESUMO

Benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC) are organosulfur phytochemicals rich in cruciferous vegetables. We investigated the antiobesity and antihepatosteatosis activities of BITC and PEITC and the working mechanisms involved. C57BL/6J mice were fed a low-fat diet (LFD), a high-fat diet (HFD), or a HFD supplemented with 0.5 (L) or 1 g/kg (H) BITC or PEITC for 18 weeks. Compared with the HFD group, BITC or PEITC decreased the final body weight of mice in a dose-dependent manner [39.0 ± 3.1 (HFD), 34.4 ± 3.2 (BITC-L), 32.4 ± 2.8 (BITC-H), 36.2 ± 4.4 (PEITC-L), and 32.8 ± 2.9 (PEITC-H) g, p < 0.05], relative weight of epididymal fat [5.7 ± 0.4 (HFD), 4.7 ± 0.7 (BITC-L), 3.7 ± 0.3 (BITC-H), 4.4 ± 1.0 (PEITC-L), and 3.2 ± 0.6 (PEITC-H) %, p < 0.05], hepatic triglycerides [98.4 ± 6.0 (HFD), 81.0 ± 8.9 (BITC-L), 63.5 ± 5.6 (BITC-H), 69.3 ± 5.6 (PEITC-L), and 49.4 ± 2.9 (PEITC-H) mg/g, p < 0.05], and plasma total cholesterol [140 ± 21.3 (HFD), 109 ± 5.6 (BITC-L), 101 ± 11.3 (BITC-H), 126 ± 8.3 (PEITC-L), and 91.8 ± 12.7 (PEITC-H) mg/dL, p < 0.05]. Q-PCR and immunoblotting assays revealed that BITC and PEITC suppressed the expression of liver X receptor α, sterol regulatory element-binding protein 1c, stearoyl-CoA desaturase 1, fatty acid synthase, and acetyl-CoA carboxylase in both epididymal adipose and liver tissues. After a single oral administration of 85 mg/kg BITC or PEITC, the maximum plasma concentrations ( Cmax) of BITC and PEITC were 5.8 ± 2.0 µg/mL and 4.3 ± 1.9 µg/mL, respectively. In 3T3-L1 adipocytes, BITC and PEITC dose-dependently reduced adipocyte differentiation and cell cycle was arrested in G0/G1 phase. These findings indicate that BITC and PEITC ameliorate HFD-induced obesity and fatty liver by down-regulating adipocyte differentiation and the expression of lipogenic transcription factors and enzymes.


Assuntos
Adipogenia/efeitos dos fármacos , Fígado Gorduroso/tratamento farmacológico , Isotiocianatos/administração & dosagem , Obesidade/tratamento farmacológico , Animais , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/fisiopatologia
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