Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 149
Filtrar
2.
Se Pu ; 39(9): 1021-1029, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34486842

RESUMO

Ion-pair reversed-phase liquid chromatography (IP-RPLC) enhances separation by adding ion-pair reagents to the mobile phase, thereby improving the retention of oppositely charged solutes. IP-RPLC is primarily used for the separation and analysis of strongly ionized compounds. In IP-RPLC, researchers often focus more on the influence of the counter-ion type and concentration, buffer salt concentration and pH, and column temperature, on the retention behavior of solutes. However, the effects of the buffer salt type and non-counter ions in ion-pair reagents on the retention behavior of solutes have rarely been investigated. Accordingly, in this work, the effects of buffer salt types and non-counter ions on the retention behavior of strongly ionized compounds were investigated by IP-RPLC using 14 sulfonic acid compounds as model compounds. Experiments were performed using a silica-based C18 column with methanol as the organic modifier. In the first type of experiment, tetrabutylammonium bromide was kept unchanged as the ion-pair reagent in the mobile phase, and ammonium dihydrogen phosphate, ammonium chloride, and ammonium acetate were used as buffer salts, respectively. The retention factor (k) was obtained at different methanol ratios, and linear solvent strength (LSS) models were established to determine the log kw (logarithm of retention factors of solutes when 100% aqueous phases were used as the mobile phase) and S (intercept of the LSS model) values of each solute. All solutes exhibited the highest log kw with the ammonium chloride buffer system; most compounds also exhibited the highest S values with this system, except for 1,5-naphthalenedisulfonic acid, 4-methylbenzenesulfonic acid, 5-amino-2-nanphthalenesulfonic acid, and 4-hydroxybenzenesulfonic acid. However, the chromatographic hydrophobic indices (CHIs, log kw/S) of the solutes with different buffer salts were approximately equal. In the second type of experiment, ammonium dihydrogen phosphate was kept unchanged as the buffer salt in the mobile phase, and tetrabutylammonium bromide, tetrabutylammonium dihydrogen phosphate, tetrabutylammonium hydrogen sulfate, tetrabutylammonium nitrate, and tetrabutylammonium acetate were used as ion-pair reagents, respectively. Almost all solutes exhibited the highest S with the tetrabutylammonium acetate system, indicating that weakly ionized anions (such as acetate ions) in ion-pair reagents will improve the S values of sulfonic acid compounds. Interestingly, the CHIs of the solutes were almost the same for solutes with different non-counter ions. These results suggest that both, the buffer salt types and non-counter ions, influence the log kw and S values of sulfonic acid compounds. Comparison of the retention behavior of solutes with different mobile phases suggested ion-pair mechanisms as well as dynamic ion-exchange mechanisms plays role in the IP-RPLC retention of sulfonic acid compounds. In addition, with all the experimental mobile phases, the apparent n-octanol/water partition coefficient (log D) presented a good linear correlation with log kw, S, and CHI, respectively, by the introduction of structure-related descriptors such as charge (ne), Abraham solvation parameters (A and B), and the polar surface area (PSA). Considering the differences in the log kw and S values obtained with different buffer salts and non-counter ions, the CHIs were relatively stable; therefore, the CHI is more suitable for establishing a quantitative structure-retention relationship (QSRR) model in IP-RPLC, compared to log kw and S.


Assuntos
Cromatografia de Fase Reversa , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Íons
3.
Mol Cancer Res ; 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465586

RESUMO

Centromere dysfunctions leading to numerical chromosome alterations are believed to be closely related to human cancers. As a centromere-specific protein, centromere protein A (CENP-A) replaces the histone H3 in centromeres and is therefore considered a key factor of centromere identity. Researches have shown that CENP-A is overexpressed in many types of human cancers. However, the behavior and function of CENP-A in tumorigenesis have not yet been systematically summarized. In this article, we describe the pleiotropic roles of CENP-A in human cells. Moreover, we provide a comprehensive review of the current knowledge on the relationship between aberrant expression and ectopic localization of CENP-A and tumorigenesis, and the mechanism of the ectopic deposition of CENP-A in cancers. Furthermore, we note that some oncogenic viruses can modulate the expression and localization of this centromere protein along with its chaperone. At last, we also discuss the therapeutic potential of targeting CENP-A for cancer therapy.

4.
Cell Metab ; 33(10): 2059-2075.e10, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34536344

RESUMO

Myocardial ischemia-reperfusion (MIR) injury is a major cause of adverse outcomes of revascularization after myocardial infarction. To identify the fundamental regulator of reperfusion injury, we performed metabolomics profiling in plasma of individuals before and after revascularization and identified a marked accumulation of arachidonate 12-lipoxygenase (ALOX12)-dependent 12-HETE following revascularization. The potent induction of 12-HETE proceeded by reperfusion was conserved in post-MIR in mice, pigs, and monkeys. While genetic inhibition of Alox12 protected mouse hearts from reperfusion injury and remodeling, Alox12 overexpression exacerbated MIR injury. Remarkably, pharmacological inhibition of ALOX12 significantly reduced cardiac injury in mice, pigs, and monkeys. Unexpectedly, ALOX12 promotes cardiomyocyte injury beyond its enzymatic activity and production of 12-HETE but also by its suppression of AMPK activity via a direct interaction with its upstream kinase TAK1. Taken together, our study demonstrates that ALOX12 is a novel AMPK upstream regulator in the post-MIR heart and that it represents a conserved therapeutic target for the treatment of myocardial reperfusion injury.

5.
Insect Sci ; 2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34427391

RESUMO

The sense of taste plays a crucial role in herbivorous insects by discriminating nutrients from complex plant metabolic compounds. The peripheral coding of taste has been thoroughly studied in many insect species, but the central gustatory pathways are poorly described. In the present study, we characterized single neurons in the gnathal ganglion of Helicoverpa armigera larvae using the intracellular recording/staining technique. We identified different types of neurons, including sensory neurons, interneurons, and motor neurons. The morphologies of these neurons were largely diverse and their arborizations seemingly covered the whole gnathal ganglion. The representation of the single neurons responding to the relevant stimuli of sweet and bitter cues showed no distinct patterns in the gnathal ganglion. We postulate that taste signals may be processed in a manner consistent with the principle of population coding in the gnathal ganglion of H. armigera larvae.

6.
J Adolesc ; 92: 75-85, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34433117

RESUMO

INTRODUCTION: This study explores the longitudinal and bidirectional relations between paternal/maternal psychological control and adolescent maladjustment (i.e., internalizing symptoms, aggression, and association with deviant peers). METHODS: This longitudinal investigation was conducted at two time points over a one-year interval with participants comprising 543 Chinese adolescents aged 10 to 13 (mean age at Time 1 = 11.29; 51.93% girls). The performed measurements encompassed paternal/maternal psychological control, adolescent internalizing symptoms, aggression, association with deviant peers, and demographic information. RESULTS: The findings of a cross-lagged model analysis revealed that paternal psychological control was longitudinally and positively related to adolescent internalizing symptoms and aggression. Maternal psychological control was not significantly related to any domain of adolescent maladjustment. In turn, adolescent association with deviant peers was longitudinally and positively associated with both parents' psychological control. CONCLUSIONS: Parental psychological control was bidirectionally associated with adolescent maladjustment in general, and paternal psychological control played a crucial role on adolescent maladjustment in the Chinese cultural context. The study's findings supported the reciprocal model of parent-child interaction, and extended it by highlighting the apprehension of the characteristics of parental impact from a cultural perspective. The study results add to the current scholarly understanding of parental psychological control in the non-western cultural context.

7.
mBio ; 12(3): e0142521, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34182774

RESUMO

Temperature compensation is a fundamental property of all circadian clocks; temperature compensation results in a relatively constant period length at different physiological temperatures, but its mechanism is unclear. Formation of a stable complex between clock proteins and casein kinase 1 (CK1) is a conserved feature in eukaryotic circadian mechanisms. Here, we show that the FRQ-CK1 interaction and CK1-mediated FRQ phosphorylation, not FRQ stability, are main mechanisms responsible for the circadian temperature compensation phenotypes in Neurospora. Inhibition of CK1 kinase activity impaired the temperature compensation profile. Importantly, both the loss of temperature compensation and temperature overcompensation phenotypes of the wild-type and different clock mutant strains can be explained by temperature-dependent alterations of the FRQ-CK1 interaction. Furthermore, mutations that were designed to specifically affect the FRQ-CK1 interaction resulted in impaired temperature compensation of the clock. Together, these results reveal the temperature-compensated FRQ-CK1 interaction, which results in temperature-compensated CK1-mediated FRQ and WC phosphorylation, as a main biochemical process that underlies the mechanism of circadian temperature compensation in Neurospora. IMPORTANCE Temperature compensation allows clocks to adapt to all seasons by having a relatively constant period length at different physiological temperatures, but the mechanism of temperature compensation is unclear. Stability of clock proteins was previously proposed to be a major factor that regulated temperature compensation. In this study, we showed that the interaction between CK1 and FRQ, but not FRQ stability, explains the circadian temperature compensation phenotypes in Neurospora. This study uncovered the key biochemical mechanism responsible for temperature compensation of the circadian clock and further established the mechanism for period length determination in Neurospora. Because the regulation of circadian clock proteins by CK1 and the formation of a stable clock complex with CK1 are highly conserved in eukaryotic clocks, a similar mechanism may also exist in animal clocks.

8.
Anal Methods ; 13(26): 2974-2980, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34114573

RESUMO

In this study, magnetic Fe3O4@SiO2@ß-cyclodextrin copolymerized microparticles were synthesized and applied for the extraction of methyl parathion and fenthion in lettuce samples followed by HPLC-UV detection. The magnetic ß-cyclodextrin copolymerized microparticles were prepared by dispersion polymerization with acryloyl ß-cyclodextrin as the functional monomer and ethylene glycol dimethyacrylate as the crosslinker. The composite magnetic microparticles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, magnetic measurement, and thermogravimetric analysis, and used as the adsorbent of magnetic solid-phase extraction (MSPE) for methyl parathion and fenthion. The extraction conditions including sample pH and ionic strength, desorption solvent type and volume, and adsorption and desorption times were optimized. Under the optimal extraction conditions, an MSPE-HPLC-UV method was developed for the detection of methyl parathion and fenthion in lettuce. Wide linear ranges of 1.0-200 µg kg-1 (R2 = 0.9998) for methyl parathion and 1.5-200 µg kg-1 (R2 = 0.9978) for fenthion were obtained and the limits of detection were 0.3 µg kg-1 for methyl parathion and 0.5 µg kg-1 for fenthion in lettuce, respectively. The proposed method was applied for the determination of methyl parathion and fenthion in lettuce with satisfactory recoveries between 89.2-101.2%, and relative standard deviations were less than 9.1%. Thus, the MSPE-HPLC-UV method has high accuracy and sensitivity for the analysis of methyl parathion and fenthion in lettuce samples.


Assuntos
Metil Paration , beta-Ciclodextrinas , Fention , Alface , Limite de Detecção , Fenômenos Magnéticos , Dióxido de Silício , Extração em Fase Sólida
9.
Elife ; 102021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33988500

RESUMO

The pheromone system of heliothine moths is an optimal model for studying principles underlying higher-order olfactory processing. In Helicoverpa armigera, three male-specific glomeruli receive input about three female-produced signals, the primary pheromone component, serving as an attractant, and two minor constituents, serving a dual function, that is, attraction versus inhibition of attraction. From the antennal-lobe glomeruli, the information is conveyed to higher olfactory centers, including the lateral protocerebrum, via three main paths - of which the medial tract is the most prominent. In this study, we traced physiologically identified medial-tract projection neurons from each of the three male-specific glomeruli with the aim of mapping their terminal branches in the lateral protocerebrum. Our data suggest that the neurons' widespread projections are organized according to behavioral significance, including a spatial separation of signals representing attraction versus inhibition - however, with a unique capacity of switching behavioral consequence based on the amount of the minor components.

10.
Nat Commun ; 12(1): 2346, 2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33879767

RESUMO

Cancer expression of PD-L1 suppresses anti-tumor immunity. PD-L1 has emerged as a remarkable therapeutic target. However, the regulation of PD-L1 degradation is not understood. Here, we identify several compounds as inducers of PD-L1 degradation using a high-throughput drug screen. We find EGFR inhibitors promote PD-L1 ubiquitination and proteasomal degradation following GSK3α-mediated phosphorylation of Ser279/Ser283. We identify ARIH1 as the E3 ubiquitin ligase responsible for targeting PD-L1 to degradation. Overexpression of ARIH1 suppresses tumor growth and promotes cytotoxic T cell activation in wild-type, but not in immunocompromised mice, highlighting the role of ARIH1 in anti-tumor immunity. Moreover, combining EGFR inhibitor ES-072 with anti-CTLA4 immunotherapy results in an additive effect on both tumor growth and cytotoxic T cell activation. Our results delineate a mechanism of PD-L1 degradation and cancer escape from immunity via EGFR-GSK3α-ARIH1 signaling and suggest GSK3α and ARIH1 might be potential drug targets to boost anti-tumor immunity and enhance immunotherapies.


Assuntos
Antígeno B7-H1/metabolismo , Neoplasias/imunologia , Neoplasias/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Antígeno B7-H1/química , Antígeno CTLA-4/antagonistas & inibidores , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Imunoterapia/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Biológicos , Neoplasias/terapia , Fosforilação , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Transdução de Sinais , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Evasão Tumoral/fisiologia , Células U937 , Ubiquitinação/efeitos dos fármacos
11.
J Sep Sci ; 44(8): 1706-1715, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33624922

RESUMO

A moisture-sensitive metal-organic framework CoII (pybz)2 ·2DMF was synthesized and applied as the adsorbent of dispersive solid-phase extraction. The structure changed after water treatment due to the fact that two chelate carboxylate groups on the skeleton were transformed to monodentate because of the coordination of water molecules. The material showed good adsorption for fluorene, phenanthrene, fluoranthene, and pyrene in water because of the π-π conjugation and π-complexation effects. Coupled with high-performance liquid chromatography, a dispersive solid-phase extraction method of determining the content of fluorene, phenanthrene, fluoranthene, and pyrene in apple samples was established after optimizing the extraction conditions. Methanol containing 4% acetic acid was used as the effective eluent. The linearities were 0.5-1000 µg/kg for fluorene, phenanthrene and 5-1000 µg/kg for fluoranthene, pyrene. The limits of detection were 0.06-0.6 µg/kg, and the recoveries were 94.4-116.4%. The method has a high sensitivity for the determination of four polycyclic aromatic hydrocarbons in apple samples.

12.
Plant Biotechnol J ; 19(1): 167-176, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32710800

RESUMO

Increased use of nitrogen fertilizers has deleterious impact on the environment. Increase in yield potential at low nitrogen supply is regarded as a cereal breeding goal for future agricultural sustainability. Although natural variations of nitrogen transporters have been investigated, key genes associated with assimilation remain largely unexplored for nitrogen use efficiency (NUE) enhancement. Here, we identified a NIN-like protein NLP4 associated with NUE through a GWAS in rice. We found that OsNLP4 transactivated OsNiR encoding nitrite reductase that was critical in nitrogen assimilation in rice. We further constructed quadrupling NREs (Nitrate-responsive cis-elements) in the promoter of OsNiR (p4xNRE:OsNiR) and enhanced nitrogen assimilation significantly. We demonstrated that OsNLP4-OsNiR increased tiller number and yield through enhancing nitrogen assimilation and NUE. Our discovery highlights the genetic modulation of OsNLP4-OsNiR signalling cascade as a strategy for high NUE and yield breeding in rice.


Assuntos
Oryza , Fertilizantes , Nitrogênio , Oryza/genética , Melhoramento Vegetal , Proteínas de Plantas/genética
13.
Int J Biol Macromol ; 168: 631-639, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33227332

RESUMO

A novel fibrinolytic enzyme, ACase was isolated from fruiting bodies of a mushroom, Agrocybe aegerita. ACase was purified by using ammonium sulfate precipitation, gel filtration, ion exchange and hydrophobic chromatographies to 237.12 fold with a specific activity of 1716.77 U/mg. ACase was found to be a heterodimer with molecular mass of 31.4 and 21.2 kDa by SDS-PAGE and appeared as a single band on Native-PAGE and fibrin-zymogram. The N-terminal sequence of the two subunits of ACase was AIVTQTNAPWGL (subunit 1) and SNADGNGHGTHV (subunit 2). ACase had maximal activity at 47 °C and pH 7.6. It's activity was improved by Cu2+, Na+, Fe3+, Zn2+, Ba2+, K+ and Mn2+, but inhibited by Fe2+, Mg2+ and Ca2+. PMSF, SBTI, aprotinine and Lys inhibited the enzyme activity, which suggested that ACase was a serine protease. ACase could degrade all three chains (α, ß and γ) of fibrinogen. Moreover, the enzyme acted as both, a plasmin-like fibrinolytic enzyme and a plasminogen activator. It could hydrolyze human thrombin slightly, which indicated that the ACase could inhibit the activity of thrombin and acted as an anticoagulant to prevent thrombosis. Based on these results, ACase might act as a therapeutic agent for treating thrombosis, or as a functional food. Further investigation of the enzyme is underway.


Assuntos
Agrocybe/enzimologia , Anticoagulantes/farmacologia , Fibrinolíticos/farmacologia , Serina Proteases/farmacologia , Sequência de Aminoácidos , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Fenômenos Químicos , Cromatografia por Troca Iônica , Fibrinogênio/metabolismo , Fibrinolíticos/química , Fibrinolíticos/isolamento & purificação , Carpóforos/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Imunoglobulina G/metabolismo , Peso Molecular , Multimerização Proteica , Serina Proteases/química , Serina Proteases/isolamento & purificação , Albumina Sérica Humana/metabolismo , Trombina/metabolismo
14.
Mol Med Rep ; 23(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33179111

RESUMO

Astragaloside (AST) is derived from the Chinese herb Astragalus membranaceus, and studies have demonstrated that it promotes differentiation of bone marrow­derived mesenchymal stem cells (BMSCs). To the best of our knowledge, however, the functions of the component AST­IV in osteogenesis have not previously been elucidated. The present study aimed to verify the effects of AST­IV in osteogenesis. First, the proliferation and differentiation status of human BMSCs incubated with AST­IV were analysed and compared with a control (no AST­IV treatment). In order to determine the involvement of the glycogen synthase kinase (GSK)3ß signalling pathway in AST­IV, overexpression and inhibition of GSK3ß was induced during incubation of BMSCs with AST­IV. In order to investigate how neuronal growth factor (NGF) contributes to BMSCs differentiation, BMSCs were co­incubated with an anti­NGF antibody and AST IV, and then levels of osteogenesis markers were assessed. The results demonstrated for the first time that AST­IV contributed to BMSCs differentiation. Furthermore, the GSK3ß/ß­catenin signalling pathway was revealed to be involved in AST­IV­induced osteogenesis; moreover, AST­IV accelerated differentiation by enhancing the expression levels of NGF. In summary, the present study demonstrated that AST­IV promotes BMSCs differentiation, thus providing a potential target for the treatment of osteoporosis.


Assuntos
Células-Tronco Mesenquimais/citologia , Osteogênese , Osteoporose/metabolismo , Saponinas/farmacologia , Triterpenos/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Fator de Crescimento Neural/metabolismo , Osteoporose/tratamento farmacológico
15.
Stem Cell Res Ther ; 11(1): 538, 2020 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-33308301

RESUMO

OBJECTIVE: Arteriosclerosis is an age-related disease and a leading cause of cardiovascular disease. In animal experiments, mesenchymal stem cells and its culture-conditioned medium have been shown to be promising tools for prevention or treatment of arteriosclerosis. On the basis of these evidences, we aimed to assess whether administration of autologous adipose-derived mesenchymal stem cells (Ad-MSC) is safe and effective for treatment of arteriosclerosis. METHODS: We retrospectively reviewed clinical records of patients with arteriosclerosis who had received autologous Ad-MSC administration at our clinic. Patients' characteristics were recorded and data on lipid profile, intimal-media thickness (IMT), cardio-ankle vascular index (CAVI), and ankle-brachial index (ABI) before and after Ad-MSC administration were collected and compared. RESULTS: Treatment with Ad-MSC significantly improved HDL, LDL, and remnant-like particle (RLP) cholesterol levels. No adverse effect or toxicity was observed in relation to the treatment. Of the patients with abnormal HDL values before treatment, the vast majority showed improvement in the values. Overall, the measurements after treatment were significantly increased compared with those before treatment (p < 0.01). In addition, decreases in LDL cholesterol and RLP levels were observed after treatment in patients who had abnormal LDL cholesterol or RLP levels before treatment. The majority of patients with pre-treatment abnormal CAVI values had improved values after treatment. In patients with available IMT values, a significant decrease in the IMT values was found after therapy (p < 0.01). All patients with borderline arteriosclerosis disease had improved laboratory findings after treatment. In general, post-treatment values were significantly decreased as compared with pre-treatment values. Of the patients with normal ABI values before treatment at the same time as CAVI, the vast majority remained normal after treatment. CONCLUSIONS: These findings suggest that Ad-MSC administration is safe and effective in patients developing arteriosclerosis, thereby providing an attractive tool for anti-aging application.


Assuntos
Arteriosclerose , Células-Tronco Mesenquimais , Envelhecimento , Índice Tornozelo-Braço , Arteriosclerose/diagnóstico por imagem , Arteriosclerose/terapia , Humanos , Estudos Retrospectivos
16.
Talanta ; 219: 121363, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887085

RESUMO

In this work, the correlations between retention behavior and lipophilicity of a large set of hydrophilic neutral and ionic analytes were studied based on three hydrophilic interaction liquid chromatography (HILIC) stationary phases, including zwitterionic, crosslinked diol and triazole stationary phases. It was found that HILIC, due to the diversity of retention mechanism, is a more complex chromatography separation mode than reversed-phase liquid chromatography (RPLC) which has been widely accepted for lipophilicity assessment. Because electrostatic interactions contributed to the overall retention of the charged solutes on all three stationary phases, ion-strength of the mobile phase kept the same during the whole experiment. After the correlations between retention factor log k and water volume fraction Φ were investigated, the mixed retention model was revealed to be more suitable for HILIC retention behavior than other single models including partitioning and adsorption model. Moreover, in order to bridge the relationship between HILIC log k and lipophilicity parameter log D, net charge ne and Abraham solvation parameter were introduced in the quantitative structure-retention relationship (QSRR) model. Although the correlation coefficients between log D and log k were still moderate, the significant improvement in correlation has made HILIC a potential choice as the complement of RPLC for log D measurement.

17.
J Agric Food Chem ; 68(43): 11954-11974, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-32907328

RESUMO

Approximately 50-80% of the world population are infected with H. pylori, which is categorized as a class I carcinogen. Antiadhesive therapy is emerging as a promising alternative to antibiotics against bacterial infection. This study demonstrated that defatted wheat germ protein hydrolysates (DWGPH) effectively inhibited H. pylori adhesion to gastric epithelial cells. DWGPH prepared by pronase possessed the best activity where its inhibitory percentage at 10 mg/mL was 51.7 ± 6.8% and the minimum antiadhesive concentration was 0.31 mg/mL. The antiadhesive activity is attributable to peptides acting as receptor analogs in binding to H. pylori. Peptides with potential H. pylori-binding ability (n = 267) were identified, and their structural characteristics were comprehensively analyzed, including net charge, Boman index, instability index, aliphatic index, molecular weight, isoelectric point, hydrophobicity, and Hmoment (α-helix and ß-sheet). This work provided an array of peptide sequences for further exploration as putative ligands of H. pylori adhesins and for elucidating molecular mechanisms.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Helicobacter pylori/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Triticum/química , Adesinas Bacterianas/efeitos dos fármacos , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/fisiologia , Humanos , Espectrometria de Massas , Proteínas de Plantas/química , Proteínas de Plantas/farmacologia
18.
Theor Appl Genet ; 133(12): 3287-3297, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32852584

RESUMO

KEY MESSAGE: Heterosis QTLs, including qSS7 and qHD8, with dominance effects were identified through GBS and large-scale phenotyping of CSSLs and hybrid F1 populations in a paddy field. Heterosis has contributed immensely to agricultural production, but its genetic basis is unclear. We evaluated dominance effects by creating two hybrid populations: a B-homo set with a homozygous background and heterozygous chromosomal segments and a B-heter set with a heterozygous background and homozygous segments. This was achieved by crossing a set of 156 backcrossed-derived chromosome segment substitution lines (CSSLs) with their recurrent parent (9311), the male parent of the first super-high-yield hybrid Liangyoupei9 (LYP9), and with the female parent (PA64s) of the hybrid. The CSSLs were subjected to a genotyping-by-sequencing analysis to develop a genetic map of segments introduced from the PA64s. We evaluated the heterotic effects on eight yield-related traits in the hybrid variety and F1 populations in large-scale field experiments over 2 years. Using a linkage map consisting of high-density SNPs, we identified heterosis-associated genes in LYP9. Five candidate genes contributed to the high yield of LYP9, with qSS7 and qHD8 repeatedly detected in both B-hybrid populations. The heterozygous segments harboring qSS7 and qHD8 showed dominance effects that contributed to the heterosis of yield components in the hybrid rice variety Liangyoupei9.


Assuntos
Cromossomos de Plantas/genética , Epistasia Genética , Vigor Híbrido , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Mapeamento Cromossômico , Oryza/genética
19.
Hypertension ; 76(3): 827-838, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32683902

RESUMO

NOX5 (NADPH oxidase 5) is a homolog of the gp91phox subunit of the phagocyte NOX, which generates reactive oxygen species. NOX5 is involved in sperm motility and vascular contraction and has been implicated in diabetic nephropathy, atherosclerosis, and stroke. The function of NOX5 in the cardiac hypertrophy is unknown. Because NOX5 is a Ca2+-sensitive, procontractile NOX isoform, we questioned whether it plays a role in cardiac hypertrophy. Studies were performed in (1) cardiac tissue from patients undergoing heart transplant for cardiomyopathy and heart failure, (2) NOX5-expressing rat cardiomyocytes, and (3) mice expressing human NOX5 in a cardiomyocyte-specific manner. Cardiac hypertrophy was induced in mice by transverse aorta coarctation and Ang II (angiotensin II) infusion. NOX5 expression was increased in human failing hearts. Rat cardiomyocytes infected with adenoviral vector encoding human NOX5 cDNA exhibited elevated reactive oxygen species levels with significant enlargement and associated increased expression of ANP (atrial natriuretic peptides) and ß-MHC (ß-myosin heavy chain) and prohypertrophic genes (Nppa, Nppb, and Myh7) under Ang II stimulation. These effects were reduced by N-acetylcysteine and diltiazem. Pressure overload and Ang II infusion induced left ventricular hypertrophy, interstitial fibrosis, and contractile dysfunction, responses that were exaggerated in cardiac-specific NOX5 trangenic mice. These phenomena were associated with increased reactive oxygen species levels and activation of redox-sensitive MAPK (mitogen-activated protein kinase). N-acetylcysteine treatment reduced cardiac oxidative stress and attenuated cardiac hypertrophy in NOX5 trangenic. Our study defines Ca2+-regulated NOX5 as an important NOX isoform involved in oxidative stress- and MAPK-mediated cardiac hypertrophy and contractile dysfunction.


Assuntos
Acetilcisteína/farmacologia , Cardiomegalia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , NADPH Oxidase 5/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Angiotensina II/farmacologia , Animais , Cardiomegalia/tratamento farmacológico , Cardiomegalia/metabolismo , Sequestradores de Radicais Livres/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Isoenzimas/metabolismo , Camundongos , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fagócitos/enzimologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Vasoconstritores/farmacologia , Miosinas Ventriculares/metabolismo
20.
Foods ; 9(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32370047

RESUMO

New glycopeptides were generated by proteolysis from corn gluten meal (CGM) followed by transglutaminase (TGase)-induced glycosylation with glucosamine (GlcN). The glycopeptides exhibited desirable antioxidant and intracellular ROS-scavenging properties. The amount of conjugated GlcN quantified by high-performance liquid chromatography (HPLC) was 23.0 g/kg protein. The formed glycopeptides contained both glycosylated and glycation types, as demonstrated by the electrospray ionization time-of-flight mass spectrometry (ESI-TOF MS/MS). The glycopeptides exhibited scavenging capabilities against free radical diphenylpicrylhydrazyl (DPPH) and hydroxyl radicals by reducing their power. The potential protection of glycopeptides against ethanol-induced injury in LO2 cells was assessed In Vitro based on methyl thiazole tetrazolium (MTT) testing and intracellular reactive oxygen species (ROS) scavenging capacity, respectively. Glycopeptide cytoprotection was expressed in a dose-dependent manner, with the glycopeptides exhibiting good solubility ranging from 74.8% to 83.2% throughout a pH range of 2-10. Correspondingly, the glycopeptides showed good emulsifying activity (36.0 m2/g protein), emulsion stability (74.9%), and low surface hydrophobicity (16.3). These results indicate that glycosylation of CGM significantly improved its biological and functional properties. Glycopeptides from CGM could be used as potential antioxidants as well as comprising a functional food ingredient.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...