Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Am Chem Soc ; 146(18): 12485-12495, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38651836

RESUMO

Understanding the mechanisms of C-H activation of alkanes is a very important research topic. The reactions of metal clusters with alkanes have been extensively studied to reveal the electronic features governing C-H activation, while the experimental cluster reactivity was qualitatively interpreted case by case in the literature. Herein, we prepared and mass-selected over 100 rhodium-based clusters (RhxVyOz- and RhxCoyOz-) to react with light alkanes, enabling the determination of reaction rate constants spanning six orders of magnitude. A satisfactory model being able to quantitatively describe the rate data in terms of multiple cluster electronic features (average electron occupancy of valence s orbitals, the minimum natural charge on the metal atom, cluster polarizability, and energy gap involved in the agostic interaction) has been constructed through a machine learning approach. This study demonstrates that the general mechanisms governing the very important process of C-H activation by diverse metal centers can be discovered by interpreting experimental data with artificial intelligence.

2.
Chemistry ; : e202402695, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39404653

RESUMO

The activation of N2 under mild conditions remains a significant challenge in chemistry. Understanding how the composition of ligands modulates the reactivity of metal centers is pivotal for the rational design of efficient catalysts for nitrogen fixation. Herein, the reactions between polynuclear niobium oxynitride anions Nb4N5-xOx- (x = 0-5) and N2 were investigated by employing mass spectrometry, photoelectron imaging spectroscopy, and theoretical calculations. The rate constants of Nb4N5-xOx-/N2 gradually decrease for x = 0 to x = 4, and then increase again for x = 5. The sharp increase of the rate constants of Nb4O5-/N2 corresponds to a decrease in the electron detachment energy of the Nb4O5- cluster in the photoelectron spectroscopic experiment. Theoretical calculations suggest that the low-coordinated Nb-Nb site in Nb4N5-xOx- (x = 0-5) behaves as the active center to bind N2 in the side-on/end-on manner. Mechanistic analysis reveals that raising the O/N ratio leads to higher electron densities on the active Nb-Nb center and decreased positive charge on the metal atoms, which hinders the approach of N2 to the clusters. This finding discloses fundamental insights into the impact of N/O ratios in fine-tuning the reactivity of metal centers towards N2 adsorption in related catalytic processes.

3.
Antonie Van Leeuwenhoek ; 117(1): 112, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39133351

RESUMO

A Gram-stain-negative, light khaki, strictly aerobic, rod-shaped, motile via multiple flagella, and catalase- and oxidase-positive bacterium, designated as SSM4.3T, was isolated from the seaweed of Gouqi Island in the East China Sea. The novel isolate grows at 0-5.0% NaCl concentrations (w/v) (optimum 1%), pH 5.0-9.0 (optimum pH 7.0), and 15-37 °C (optimum 30 °C). The 16S rRNA gene sequences-based phylogeny indicates that the novel marine isolate belongs to the family Rhizobiaceae and that it shared the greatest sequence similarity (98.9%) with Peteryoungia rhizophila CGMCC 1.15691T. This classification was also supported by phylogenetic analysis using core genes. The predominant fatty acids (≥ 10%) of the strain were identified as C18:1 ω7c/C18:1 ω6c. Q-10 was identified as the major isoprenoid quinone, with trace levels of Q-9 present. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The complete genome size of strain SSM4.3T is 4.39 Mb with a DNA G+C content of 61.3%. The average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values between the genomes of strain SSM4.3T and its closely related representatives were 74.80-86.93%, 20.00-32.30%, and 70.30-91.52%, respectively. Phylogenetic analysis, grounded on the core genes, reveals the evolutionary relationship between SSM4.3T and other Peteryoungia strains. Pan-genomics analysis of 8 previously classified Peteryoungia species and SSM4.3T revealed their unique genetic features and functions. Overall, strain SSM4.3T was considered to be a new species of the Peteryoungia genus; the name Peteryoungia algae sp. nov. has been proposed, with type strain SSM4.3T (= LMG 32561 = MCCC 1K07170).


Assuntos
Composição de Bases , DNA Bacteriano , Ácidos Graxos , Filogenia , RNA Ribossômico 16S , Alga Marinha , China , RNA Ribossômico 16S/genética , Alga Marinha/microbiologia , DNA Bacteriano/genética , Ácidos Graxos/análise , Ácidos Graxos/química , Técnicas de Tipagem Bacteriana , Genoma Bacteriano , Análise de Sequência de DNA , Ilhas , Hibridização de Ácido Nucleico
4.
Curr Microbiol ; 81(9): 283, 2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39066927

RESUMO

A novel bacterium designated as SSA5.23T was isolated from seawater. Cells of SSA5.23T are Gram-stain-negative, short, rod-shaped, and exhibit motility via numerous peritrichous flagella. The strain could grow at temperatures ranging from 15 to 35 °C (optimum at 25 °C), in a salinity range of 0-5.0% (w/v) NaCl, and within a pH range of 6.0-9.0 (optimum at pH 7.0). The predominant cellular fatty acid of SSA5.23T was C18:1 ω7c/C18:1 ω6c, and the major respiratory quinones were Q-9 and Q-10. Diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol were identified as the primary polar lipids. The complete genome (5.47 Mb) of SSA5.23T comprises of a circular chromosome of 3.64 Mb and three plasmids, specifically sized at 59.73 kb, 227.82 kb, and 1.54 Mb, respectively. Certain genes located on the plasmids play roles in denitrification, oxidative stress resistance, and osmotic tolerance, which likely contribute to the adaptability of this strain in marine conditions. Core-proteome average amino acid identity analysis effectively identified the strain's affiliation with the genus Affinirhizobium, showing the highest value (89.9%) with Affinirhizobium pseudoryzae DSM 19479T. This classification was further supported by the phylogenetic analysis of concatenated alignment of 170 single-copy orthologous proteins. When compared to related reference strains, SSA5.23T displayed an average nucleotide identity ranging from 74.9 to 80.3% and digital DNA-DNA hybridization values ranging from 19.9 to 23.9%. Our findings confirmed that strain SSA5.23T represents a novel species of the genus Affinirhizobium, for which the name Affinirhizobium gouqiense sp. nov. (type strain SSA5.23T = LMG 32560T = MCCC 1K07165T) was suggested.


Assuntos
DNA Bacteriano , Ácidos Graxos , Genoma Bacteriano , Filogenia , Água do Mar , Água do Mar/microbiologia , China , Ácidos Graxos/análise , DNA Bacteriano/genética , Rhizobium/genética , Rhizobium/classificação , Rhizobium/isolamento & purificação , Composição de Bases , Técnicas de Tipagem Bacteriana , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ilhas , Genômica
5.
Antonie Van Leeuwenhoek ; 115(1): 33-40, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34743249

RESUMO

A Gram-stain-negative, wheat, rod-shaped, non-motile, non-spore forming, and facultatively anaerobic bacterium strain, designated as PIT, was isolated from saline silt samples collected in saltern in Yantai, Shandong, China. Growth was observed within the ranges 4-45 °C (optimally at 33 °C), pH 6.0-9.0 (optimally at pH 7.0) and 1.0-11.0% NaCl (optimally at 3.0%, w/v). Strain PIT showed highest 16S rRNA gene sequence similarity to Kangiella sediminilitoris BB-Mw22T (98.3%) and Kangiella taiwanensis KT1T (98.3%). The major cellular fatty acids (> 10% of the total fatty acids) were iso-C15:0 (52.7%) and summed featured 9 (iso-C17:1ω9c/C16:0 10-methyl, 11.8%). The major polar lipids identified were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine and phosphatidylglycerol. The major respiratory isoprenoid quinone was Q-8. The G + C content of the genomic DNA was 45.8%. Average Nucleotide Identity values between whole genome sequences of strain PIT and next related type strains supported the novel species status. Based on physiological, biochemical, chemotaxonomic characteristics and genomic analysis, strain PIT is considered to represent a novel species within the genus Kangiella, for which the name Kangiella shandongensis sp. nov. is proposed. The type strain is PIT (= KCTC 82509 T = MCCC 1K04352T).


Assuntos
RNA Ribossômico 16S , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Circ Res ; 124(9): 1350-1359, 2019 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-30836825

RESUMO

RATIONALE: ßARs (ß-adrenergic receptors) are prototypical GPCRs (G protein-coupled receptors) that play a pivotal role in sympathetic regulation. In heart cells, ß1AR signaling mediates a global response, including both l-type Ca2+ channels in the sarcolemma/T tubules and RyRs (ryanodine receptors) in the SR (sarcoplasmic reticulum). In contrast, ß2AR mediates local signaling with little effect on the function of SR proteins. OBJECTIVE: To investigate the signaling relationship between ß1ARs and ß2ARs. METHOD AND RESULTS: Using whole-cell patch-clamp analyses combined with confocal Ca2+ imaging, we found that the activation of compartmentalized ß2AR signaling was able to convert the ß1AR signaling from global to local mode, preventing ß1ARs from phosphorylating RyRs that were only nanometers away from sarcolemma/T tubules. This offside compartmentalization was eliminated by selective inhibition of ß2AR, GRK2 (GPCR kinase-2), ßarr1 (ß-arrestin-1), and phosphodiesterase-4. A knockin rat model harboring mutations of the last 3 serine residues of the ß1AR C terminus, a component of the putative ßarr1 binding site and GRK2 phosphorylation site, eliminated the offside compartmentalization conferred by ß2AR activation. CONCLUSIONS: ß2AR stimulation compartmentalizes ß1AR signaling into nanoscale local domains in a phosphodiesterase-4-dependent manner by targeting the C terminus of ß1ARs. This finding reveals a fundamental negative feed-forward mechanism that serves to avoid the cytotoxicity of circulating catecholamine and to sharpen the transient ß1AR response of sympathetic excitation.


Assuntos
Receptores Adrenérgicos beta 1/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Adrenérgicos/farmacologia , Animais , Células Cultivadas , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Masculino , Mutação , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Ratos Transgênicos , Receptores Adrenérgicos beta 1/química , Receptores Adrenérgicos beta 1/genética , Receptores Adrenérgicos beta 2/genética , Sarcolema/efeitos dos fármacos , Sarcolema/metabolismo , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo , Transdução de Sinais/efeitos dos fármacos
7.
Mar Drugs ; 19(11)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34822499

RESUMO

Alginate, the most abundant polysaccharides of brown algae, consists of various proportions of uronic acid epimers α-L-guluronic acid (G) and ß-D-mannuronic acid (M). Alginate oligosaccharides (AOs), the degradation products of alginates, exhibit excellent bioactivities and a great potential for broad applications in pharmaceutical fields. Alginate lyases can degrade alginate to functional AOs with unsaturated bonds or monosaccharides, which can facilitate the biorefinery of brown algae. On account of the increasing applications of AOs and biorefinery of brown algae, there is a scientific need to explore the important aspects of alginate lyase, such as catalytic mechanism, structure, and property. This review covers fundamental aspects and recent developments in basic information, structural characteristics, the structure-substrate specificity or catalytic efficiency relationship, property, molecular modification, and applications. To meet the needs of biorefinery systems of a broad array of biochemical products, alginate lyases with special properties, such as salt-activated, wide pH adaptation range, and cold adaptation are outlined. Withal, various challenges in alginate lyase research are traced out, and future directions, specifically on the molecular biology part of alginate lyases, are delineated to further widen the horizon of these exceptional alginate lyases.


Assuntos
Alginatos/farmacologia , Phaeophyceae , Polissacarídeos/farmacologia , Alginatos/química , Animais , Organismos Aquáticos , Humanos , Polissacarídeos/química , Relação Estrutura-Atividade , Especificidade por Substrato
8.
Phytother Res ; 35(7): 3898-3915, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33860590

RESUMO

Isoliquiritigenin (ISO) is a flavonoid extracted from the root of licorice, which serves various biological and pharmacological functions including antiinflammatory, antioxidation, liver protection, and heart protection. However, the mechanism of its action remains elusive and the direct target proteins of ISO have not been identified so far. Through cell-based screening, we identified ISO as a potent lipid-lowering compound. ISO treatment successfully ameliorated fatty acid-induced cellular lipid accumulation and improved nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) by increasing PPARα-dependent lipid oxidation and decreasing SREBPs-dependent lipid synthesis. Both these signaling required the activation of SIRT1. Knockdown of SIRT1 resulted in the reversal of ISO beneficiary effects suggesting that the lipid-lowering activity of ISO was regulated by SIRT1 expression. To identify the direct target of ISO, limited proteolysis combined with mass spectrometry (LiP-SMap) strategy was applied and IQGAP2 was identified as the direct target for ISO in regulating lipid homeostasis. In the presence of ISO, both mRNA and protein levels of SIRT1 were increased; however, this effect was abolished by blocking IQGAP2 expression using siRNA. To explore how IQGAP2 regulated the expression level of SIRT1, proteome profiler human phospho-kinase array kit was used to reveal possible phosphorylated kinases and signaling nodes that ISO affected. We found that through phosphorylation of CREB, ISO transduced signals from IQGAP2 to upregulate SIRT1 expression. Thus, we not only demonstrated the molecular basis of ISO in regulating lipid metabolism but also exhibited for the first time a novel IQGAP2-CREB-SIRT1 axis in treating NAFLD/NASH.


Assuntos
Chalconas , Hepatopatia Gordurosa não Alcoólica , Animais , Chalconas/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Metabolismo dos Lipídeos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Sirtuína 1/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo
9.
Zhongguo Zhong Yao Za Zhi ; 46(23): 6224-6230, 2021 Dec.
Artigo em Zh | MEDLINE | ID: mdl-34951249

RESUMO

Alzheimer's disease(AD) patients in China have been surging, and the resultant medical burden and care demand have a huge impact on the development of individuals, families, and the society. The active component compound of Epimedii Folium, Astragali Radix, and Puerariae Lobatae Radix(YHG) can regulate the expression of iron metabolism-related proteins to inhibit brain iron overload and relieve hypofunction of central nervous system in AD patients. Hepcidin is an important target regulating iron metabolism. This study investigated the effect of YHG on the expression of a disintegrin and metalloprotease-17(ADAM17), a key enzyme in the hydrolysis of ß amyloid precursor protein(APP) in HT22 cells, by mediating hepcidin. To be specific, HT22 cells were cultured in vitro, followed by liposome-mediated siRNA transfection to silence the expression of hepcidin. Real-time PCR and Western blot were performed to examine the silencing result and the effect of YHG on hepcidin in AD cell model. HT22 cells were randomized into 7 groups: control group, Aß25-35 induction(Aß) group, hepcidin-siRNA(siRNA) group, Aß25-35 + hepcidin-siRNA(Aß + siRNA) group, Aß25-35+YHG(Aß+YHG) group, hepcidin-siRNA+YHG(siRNA+YHG) group, Aß25-35+hepcidin-siRNA+YHG(Aß+siRNA+YHG) group. The expression of ADAM17 mRNA in cells was detected by real-time PCR, and the expression of ADAM17 protein by immunofluorescence and Western blot. Immunofluorescence showed that the ADAM17 protein expression was lower in the Aß group, siRNA group, and Aß+siRNA group than in the control group(P<0.05) and the expression was lower in the Aß+siRNA group(P<0.05) and higher in the Aß+YHG group(P<0.05) than in the Aß group. Moreover, the ADAM17 protein expression was lower in the Aß+siRNA group(P<0.05) and higher in the siRNA+YHG group(P< 0.05) than in the siRNA group. The expression was higher in the Aß+siRNA+YHG group than in the Aß+siRNA group(P<0.05). The results of Western blot and real-time PCR were consistent with those of immunofluorescence. The experiment showed that YHG induced hepcidin to up-regulate the expression of ADAM17 in AD cell model and promote the activation of non-starch metabolic pathways, which might be the internal mechanism of YHG in preventing and treating AD.


Assuntos
Doença de Alzheimer , Medicamentos de Ervas Chinesas , Pueraria , Proteína ADAM17 , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Peptídeos beta-Amiloides , Medicamentos de Ervas Chinesas/farmacologia , Hepcidinas/genética , Humanos
10.
Clin Gastroenterol Hepatol ; 18(11): 2564-2572.e1, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32109631

RESUMO

BACKGROUND & AIMS: Portal vein thrombosis (PVT) is a common and serious complication in patients with cirrhosis. However, little is known about PVT in patients with cirrhosis and acute decompensation (AD). We investigated the prevalence and clinical significance of PVT in nonmalignant patients with cirrhosis and AD. METHODS: We performed a retrospective study of 2 cohorts of patients with acute exacerbation of chronic liver disease who participated in the Chinese AcuTe on CHronic LIver FailurE study, established by the Chinese Chronic Liver Failure Consortium, from January 2015 through December 2016 (n = 2600 patients) and July 2018 through January 2019 (n = 1370 patients). We analyzed data on the prevalence, clinical manifestations, and risk factors of PVT from 2826 patients with cirrhosis, with and without AD. RESULTS: The prevalence of PVT in patients with cirrhosis and AD was 9.36%, which was significantly higher than in patients with cirrhosis without AD (5.24%) (P = .04). Among patients with cirrhosis and AD, 63.37% developed PVT recently (the first detected PVT with no indication of chronic PVT). Compared with patients without PVT, a significantly higher proportion of patients with PVT had variceal bleeding (47.33% vs 19.63%; P < .001) and patients with PVT had a significantly higher median serum level of D-dimer (2.07 vs 1.25; P < .001). Splenectomy and endoscopic sclerotherapy were independent risk factors for PVT in patients with cirrhosis and AD. The 1-year mortality rate did not differ significantly between patients with vs without PVT. CONCLUSIONS: In an analysis of data from 2826 patients with cirrhosis, a significantly higher proportion of those with AD had PVT than those without AD. PVT was associated with increased variceal bleeding, which would increase the risk for AD. Strategies are needed to prevent PVT in patients with cirrhosis, through regular screening, to reduce portal hypertension. ClinicalTrials.gov no: NCT02457637 and NCT03641872.


Assuntos
Varizes Esofágicas e Gástricas , Trombose Venosa , Varizes Esofágicas e Gástricas/complicações , Varizes Esofágicas e Gástricas/epidemiologia , Varizes Esofágicas e Gástricas/patologia , Hemorragia Gastrointestinal/patologia , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Veia Porta/patologia , Prevalência , Estudos Retrospectivos , Trombose Venosa/complicações , Trombose Venosa/epidemiologia , Trombose Venosa/patologia
11.
Fish Shellfish Immunol ; 97: 571-580, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31669280

RESUMO

NK-lysins, a type of broad-spectrum antimicrobial peptide (AMP), act as an essential effector of innate defense against microbial attack in higher vertebrates and so in fish. The present study delineates the structural and functional characterization of NK-lysin from yellow catfish (Pelteobagrus fulvidrac) (Pelteobagrus fulvidraco). PfNK-lysin encodes a 153-residue peptide, which displays the hallmark features of other known NK-lysins with the ordered array of six well-conserved cysteine residues and five-exon/four-intron structure. It was found to be ubiquitous in tissues, being detected most abundantly in gill and head kidney. In vivo exposure to stimuli (LPS, PolyI:C, and Edwardsiella ictaluri) induced PfNK-lysin expression in head kidney and spleen. Synthetic PfNK-lysin-derived peptide exhibited in vitro bactericidal potency against both Gram-positive and Gram-negative bacteria, with the highest inhibitory effect on pathogen Edwardsiella ictaluri. Fluorescence microscopy and scanning electron microscopy further confirmed its capacity to cause damage to the bacterial plasma membrane. Taken together, these data suggest that PfNK-lysin might participate in antimicrobial defense of yellow catfish by membrane-disruptive action.


Assuntos
Peixes-Gato/metabolismo , Proteínas de Peixes/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Proteolipídeos/farmacologia , Animais , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/efeitos dos fármacos , Edwardsiella ictaluri/imunologia , Proteínas de Peixes/isolamento & purificação , Lipopolissacarídeos/farmacologia , Poli I-C/farmacologia , Proteolipídeos/isolamento & purificação
12.
Toxicol Appl Pharmacol ; 369: 60-72, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30831131

RESUMO

Hypoxic pulmonary vasoconstriction (HPV) can be modulated by Rho/Rho kinase signaling, which can alter HPV vascular function via regulating myosin light chain phosphorylation, in a manner generally believed to be Ca2+-independent. We hypothesized that the RhoA/ROCK signaling pathway also can regulate HPV vascular function via a Ca2+-dependent mechanism, signaling through the functional transient receptor potential canonical (TRPC) channels. In this study, male BALB/c mice were exposed to normoxic or 10% oxygen (hypoxic) conditions for six weeks, after which systolic pressure and right ventricular hypertrophy were assessed. Transient intracellular calcium was monitored using a fluorescence imaging system. Muscle tension was measured with a contractile force recording system, and protein expression was assessed by immunoblotting. We found that the expressions of RhoA and ROCK were increased in mouse pulmonary arteries (PAs) under conditions of chronic hypoxia. Inhibition of the RhoA/ROCK signaling pathway prevented the development of hypoxic pulmonary hypertension (HPH), as evidenced by significantly reduced PA remodeling and pulmonary vasoconstriction. Immunoblotting results revealed that inhibition of the RhoA/ROCK signaling pathway significantly decreased the expression of HIF-1α. Knockdown of HIF-1α down-regulated the expression and function of the TRPC1 and TRPC6 channels in PASMCs under conditions of hypoxia. Contraction of the PAs and a Ca2+ influx into PASMCs through either receptor- or store-operated Ca2+ channels were also increased after hypoxia. However, RhoA/ROCK inhibitors markedly attenuated these changes. These results indicate that inhibition of the RhoA/ROCK signaling pathway ameliorates HPH via HIF-1α-dependent functional TRPCs.


Assuntos
1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/análogos & derivados , Amidas/farmacologia , Anti-Hipertensivos/farmacologia , Pressão Arterial/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Hipertensão Arterial Pulmonar/prevenção & controle , Piridinas/farmacologia , Canais de Cátion TRPC/metabolismo , Quinases Associadas a rho/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/metabolismo , 1-(5-Isoquinolinasulfonil)-2-Metilpiperazina/farmacologia , Animais , Sinalização do Cálcio , Linhagem Celular , Modelos Animais de Doenças , Hipóxia/complicações , Hipóxia/enzimologia , Hipóxia/fisiopatologia , Masculino , Camundongos Endogâmicos BALB C , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/enzimologia , Hipertensão Arterial Pulmonar/enzimologia , Hipertensão Arterial Pulmonar/etiologia , Hipertensão Arterial Pulmonar/fisiopatologia , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/enzimologia , Artéria Pulmonar/fisiopatologia , Canais de Cátion TRPC/genética , Canal de Cátion TRPC6/genética , Canal de Cátion TRPC6/metabolismo , Vasoconstrição/efeitos dos fármacos , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/genética
13.
Toxicol Appl Pharmacol ; 341: 56-63, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29355567

RESUMO

BACKGROUND: Atherosclerosis is characterized by chronic inflammation in vascular wall. Previous studies suggest that Kuwanon G (KWG) exerts anti-inflammatory activities. However, the effect of KWG on atherosclerosis remains unexplored. AIMS: To explore whether KWG affects macrophage foam cell formation in vitro and atherogenesis in vivo. METHODS: RAW 264.7 macrophages were stimulated with ox-LDL for 24h to induce foam cell formation and treated with KWG. Foam cell formation was determined by ORO staining and enzymatic analysis. Pro-inflammatory cytokines mRNA levels were tested by Real-time PCR method. Further molecular mechanism was investigated using Western blot. In vivo, ApoE-/- mice were fed with high-fat diet and intraperitoneally injected with KWG. Atherosclerotic lesion was accessed by H&E and ORO staining. Plaque composition was evaluated by immunohistochemistry and Sirius Red staining. Serum lipid profile and inflammatory cytokines were evaluated by enzymatic method and ELISA. RESULTS: KWG significantly decreased intracellular lipid accumulation and inflammatory cytokines mRNA levels in macrophages through enhancing LXRα-ABCA1/ABCG1 pathway and inhibiting NFκB activation. Administrated with KWG remarkably reduced the atherosclerotic lesion areas and macrophage content in the plaque of high-fat diet fed ApoE-/- mice. KWG also reduced hyperlipidemia and serum inflammatory cytokines in vivo. CONCLUSION: Taken together, these data highlight that KWG can attenuate atherosclerosis through inhibiting foam cell formation and inflammatory response.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/biossíntese , Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/biossíntese , Aterosclerose/metabolismo , Flavonoides/farmacologia , Receptores X do Fígado/biossíntese , Macrófagos/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Aterosclerose/etiologia , Aterosclerose/prevenção & controle , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Dieta Hiperlipídica/efeitos adversos , Relação Dose-Resposta a Droga , Flavonoides/uso terapêutico , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células RAW 264.7 , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
14.
Molecules ; 23(12)2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30544561

RESUMO

Semen Allii Fistulosi (PSAF) is the seed of Allium fistulosum L. of the Liliaceae family. The purpose of this study was to extract, characterize, and evaluate the antioxidant activity in vitro of proteins. Using single factor and orthogonal design, the optimum conditions of extraction were determined to be as follows: extraction time 150 min, pH 8.5, temperature 60 °C, and ratio (v/w, mL/g) of extraction solvent to raw material 35. The isoelectric point of the pH was determined to be about 4.4 and 10.2, by measuring the protein content of PSAF solutions at different pH values. The amino acid composition of PSAF was determined by high performance liquid chromatography (HPLC), and the results suggested that the species of amino acids contained in the PSAF was complete. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS⁻PAGE) analysis showed the molecular weight was mainly between 40 and 55 kDa, and Fourier-transform infrared spectroscopy (FTIR) characterized prevalent protein absorption peaks. PSAF exhibited potent scavenging activities against DPPH assays, via targeting of hydroxyl and superoxide radicals, while chelating Fe2+ activity and demonstrating weak reducing power. This work revealed that PSAF possessed potential antioxidant activity in vitro, suggesting potential for use of PSAF as a natural antioxidant.


Assuntos
Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Liliaceae/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Sementes/química , Aminoácidos/análise , Sequestradores de Radicais Livres/química , Concentração de Íons de Hidrogênio , Padrões de Referência , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo
15.
Molecules ; 23(10)2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30360380

RESUMO

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC50 value of 4.13 µM. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and Ki and KI values were determined to be 0.47 µM and 4.41 µM. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin.


Assuntos
Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Melilotus/química , Extratos Vegetais/farmacologia , Xantina Oxidase/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Modelos Moleculares , Conformação Molecular , Extratos Vegetais/química , Ligação Proteica , Solubilidade , Relação Estrutura-Atividade
16.
Fish Shellfish Immunol ; 70: 593-608, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28866276

RESUMO

Edwardsiella ictaluri is one of the most important pathogens posing a serious threat for yellow catfish (Pelteobagrus fulvidraco), a highly valuable fish species of increasing commercial interest in China. Here, a transcriptomic strategy was undertaken to investigate the yellow catfish gene expression profile against infection by the bacterial pathogen E. ictaluri. Comparison of the transcriptome profiles between the infected and uninfected samples showed that a massive gene expression change occurred in yellow catfish following bacterial exposure. A total of 5527 differentially expressed genes (DEGs) were detected, of which 2265 showed up-regulation and 3262 down-regulation. Gene set enrichment analysis revealed the presence of canonical pathways directly linked to innate and adaptive immune response, such as pattern recognition receptor (PRR) signaling pathways, complement and coagulation cascades, as well as T-cell receptor (TCR) and B-cell receptor (BCR) signaling pathways. Additionally, 47,526 putative EST-liked simple sequence repeats (SSRs) markers were retrieved for use in genetic studies. This study establishes the first molecular clues to understand the potential mechanisms of yellow catfish resistance to E. ictaluri, thus enabling future efforts on disease control programs in this valuable aquaculture species.


Assuntos
Peixes-Gato/genética , Peixes-Gato/imunologia , Doenças dos Peixes/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Imunidade Inata/genética , Transcriptoma , Animais , Edwardsiella ictaluri/fisiologia , Infecções por Enterobacteriaceae/imunologia , Perfilação da Expressão Gênica/veterinária , Proteínas NLR/genética , Filogenia , Receptores Toll-Like/genética
17.
Lipids Health Dis ; 14: 113, 2015 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-26387083

RESUMO

BACKGROUND: Triglycerides (TGs) are proatherogenic lipoproteins involving the risk of coronary heart disease (CHD), while apolipoprotein A5 (APOA5) and apolipoprotein C3 (APOC3) are main lipoproteins composing TG-rich lipoproteins. In this study, we aim to explore the correlation of CHD with APOA5 -1131 T > C and APOC3 -455 T > C single nucleotide polymorphisms (SNPs). METHODS: A sum of 210 CHD patients, hospitalized between Jan. 2013 and Mar. 2015 at China-Japan Union Hospital, Jilin University, were selected as our case group and 223 healthy individuals who had physical examination at same hospital at the same period were selected as control group. The frequency distribution of genotypes of APOA5 -1131 T > C and APOC3 -455 T > C SNPs were measured by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The Stata 12.0 software was utilized for statistical analyses. RESULTS: There was no significant difference on age and sex between case and control group (P > 0.05). History of smoking, drinking, hypertension and diabetes mellitus, body mass index and levels of TG and fasting blood sugar in case group were shown to be higher than control group (P < 0.05), while levels of total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in case group were lower than control group (P < 0.05). Both CC and TC' + CC frequencies of APOA5 -1131 T > C and APOC3 -455 T > C in case group were higher compared to control group (both P < 0.05). Additionally, T allele frequencies of the two SNPs in case group were lower than control group, while C allele in case group has higher frequencies compared to control group (both P < 0.05). The results of meta-analysis under allele and dominant models showed that APOA5 -1131 T > C and APOC3 -455 T > C SNPs are likely to increase the risk of CHD (both P < 0.05). CONCLUSION: APOA5 -1131 T > C and APOC3 -455 T > C SNPs may play potent roles in the development and progression of CHD.


Assuntos
Apolipoproteína C-III/genética , Apolipoproteínas A/genética , Doença das Coronárias/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Idoso , Idoso de 80 Anos ou mais , Alelos , Apolipoproteína A-V , Apolipoproteína C-III/sangue , Apolipoproteínas A/sangue , Estudos de Casos e Controles , Doença das Coronárias/sangue , Doença das Coronárias/patologia , Feminino , Expressão Gênica , Frequência do Gene , Genótipo , Humanos , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Risco , Triglicerídeos/sangue
18.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 46(4): 542-7, 2015 Jul.
Artigo em Zh | MEDLINE | ID: mdl-26480655

RESUMO

OBJECTIVE: To determine the role of infiltrated T cells in the accumulation of myeloid-derived suppressor cells (MDSCs) in tumor microenvironment. METHODS: T-cell-deficient nude mice models were established using BALB/c mice. Growth of tumors was compared between those with and without adoptive transfer of T cells. Pathological changes of the tumors were examined with HE histological analysis. The levels of MDSCs were detected with flow cytometry (FACS). RESULTS: Tumor growth was promoted in T-cell-deficient nude mice, which was accompanied with lower levels of MDSCs compared with BALB/c mice (P < 0.05). T cell transfer increased the level of MDSCs significantly (P < 0.05). T cells depletion decreased the level of MDSCs (P < 0.05). CONCLUSION: Infiltrated T cells induce the accumulation of MDSCs in tumor microenvironment, and influence tumor growth.


Assuntos
Células Mieloides/citologia , Neoplasias/patologia , Linfócitos T/citologia , Microambiente Tumoral , Animais , Citometria de Fluxo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus
19.
Zhongguo Dang Dai Er Ke Za Zhi ; 17(5): 435-9, 2015 May.
Artigo em Zh | MEDLINE | ID: mdl-26014690

RESUMO

OBJECTIVE: To study the diagnostic value and influencing factors for amplitude-integrated EEG (aEEG) in brain injury in preterm infants. METHODS: One hundred and sixteen preterm infants with a gestational age (GA) between 27 weeks and 36(+6) weeks were enrolled as subjects. The aEEG scores of all preterm infants were obtained within 6 hours after birth. According to the diagnostic results, the 116 preterm infants were divided into two groups: brain injury (n=63) and non-brain injury (n=53). The risk factors for brain injury were evaluated using logistic regression analysis. According to the aEEG results, the 116 preterm infants were divided into two groups: normal aEEG (n=58) and abnormal aEEG (n=58). The influencing factors for aEEG results in preterm infants were determined using univariate analysis. RESULTS: The brain injury group had a significantly higher rate of abnormal aEEG than the non-brain injury group (83% vs 11%; P<0.05). The infants in the brain injury group from two different GA subgroups (27-33(+6) weeks and 34-36(+6) weeks) had significantly lower aEEG scores than the non-brain injury group from corresponding GA subgroups (P<0.01). Logistic regression analysis showed that low GA (<32 weeks), low birth weight (<1 500 g), abnormal placenta, fetal membranes, and umbilical cord, and hypertension during pregnancy were high-risk factors for brain injury (P<0.05). There were significant differences in GA, birth weight, abnormal placenta, fetal membranes, and umbilical cord, and hypertension during pregnancy between the normal and abnormal aEEG groups (P<0.05). CONCLUSIONS: The risk factors for brain injury are consistent with the influencing factors for aEEG results in preterm infants, suggesting that aEEG contributes to the early diagnosis of brain injury.


Assuntos
Lesões Encefálicas/fisiopatologia , Eletroencefalografia , Peso ao Nascer , Lesões Encefálicas/diagnóstico , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Modelos Logísticos , Gravidez , Fatores de Risco
20.
Zhongguo Zhong Yao Za Zhi ; 39(16): 3107-11, 2014 Aug.
Artigo em Zh | MEDLINE | ID: mdl-25509296

RESUMO

Twelve compounds were isolated from the rhizome of Paris mairei Lévl by silica gel, Sephadex LH-20 and ODS col-umn chromatographies. The structure elucidation was accomplished by ESI-MS and NMR methods. These compounds were identified as lupeol(1), lup-20(29) -ene-3ß-yl octacosanoate(2), palmitic acid(3), glyceryl α-mono-palmitate(4), α-spinasterol(5), diosgenin (6), (25R) diosgenin-3-O-α-L-rhamnopyranosyl (1--> 4) -α-L-rhamnopyranosyl (1 --> 4) - [α-L-rhamnopyranosyl(1 --> 2)] -ß-D-glucopyranoside(7), pennogenin(8), pennogenin-3-O-ß-D-glucopyranosyl(1 -->3) - [α-L-rhamnopyranosyl(1 --> 2)] -ß-D-glucopyranoside(9), flazin(10), calonysterone(11), and isorhamnetin-3-O-ß-gentiobioside(12). Compounds 1-5,10-11 were isolated from the genus Paris for the first time, and all compounds were isolated from this plant for the first time.


Assuntos
Medicamentos de Ervas Chinesas/química , Liliaceae/química , Rizoma/química , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa