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1.
Mar Drugs ; 22(5)2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38786621

RESUMEN

Alginate oligosaccharides (AOS), products of alginate degradation by endotype alginate lyases, possess favorable biological activities and have broad applications. Although many have been reported, alginate lyases with homogeneous AOS products and secretory production by an engineered host are scarce. Herein, the alginate lyase AlyC7 from Vibrio sp. C42 was characterized as a trisaccharide-producing lyase exhibiting high activity and broad substrate specificity. With PelB as the signal peptide and 500 mM glycine as the additive, the extracellular production of AlyC7 in Escherichia coli reached 1122.8 U/mL after 27 h cultivation in Luria-Bertani medium. The yield of trisaccharides from sodium alginate degradation by the produced AlyC7 reached 758.6 mg/g, with a purity of 85.1%. The prepared AOS at 20 µg/mL increased the root length of lettuce, tomato, wheat, and maize by 27.5%, 25.7%, 9.7%, and 11.1%, respectively. This study establishes a robust foundation for the industrial and agricultural applications of AlyC7.


Asunto(s)
Escherichia coli , Polisacárido Liasas , Trisacáridos , Vibrio , Polisacárido Liasas/metabolismo , Trisacáridos/biosíntesis , Vibrio/enzimología , Especificidad por Sustrato , Alginatos , Zea mays , Oligosacáridos
2.
Microb Cell Fact ; 22(1): 179, 2023 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-37689719

RESUMEN

BACKGROUND: Alginate oligosaccharides (AOs) are the degradation products of alginate, a natural polysaccharide abundant in brown algae. AOs generated by enzymatic hydrolysis have diverse bioactivities and show broad application potentials. AOs production via enzymolysis is now generally with sodium alginate as the raw material, which is chemically extracted from brown algae. In contrast, AOs production by direct degradation of brown algae is more advantageous on account of its cost reduction and is more eco-friendly. However, there have been only a few attempts reported in AOs production from direct degradation of brown algae. RESULTS: In this study, an efficient Laminaria japonica-decomposing strain Pseudoalteromonas agarivorans A3 was screened. Based on the secretome and mass spectrum analyses, strain A3 showed the potential as a cell factory for AOs production by secreting alginate lyases to directly degrade L. japonica. By using the L. japonica roots, which are normally discarded in the food industry, as the raw material for both fermentation and enzymatic hydrolysis, AOs were produced by the fermentation broth supernatant of strain A3 after optimization of the alginate lyase production and hydrolysis parameters. The generated AOs mainly ranged from dimers to tetramers, among which trimers and tetramers were predominant. The degradation efficiency of the roots reached 54.58%, the AOs production was 33.11%, and the AOs purity was 85.03%. CONCLUSION: An efficient, cost-effective and green process for AOs production directly from the underutilized L. japonica roots by using strain A3 was set up, which differed from the reported processes in terms of the substrate and strain used for fermentation and the AOs composition. This study provides a promising platform for scalable production of AOs, which may have application potentials in industry and agriculture.


Asunto(s)
Alginatos , Laminaria , Análisis Costo-Beneficio , Oligosacáridos
3.
Appl Environ Microbiol ; 88(23): e0155922, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36394323

RESUMEN

Alginate lyases play a vital role in the degradation of alginate, an important marine carbon source. Alginate is a complex macromolecular substrate, and the synergy of alginate lyases is important for the alginate utilization by microbes and the application of alginate lyases in biotechnology. Although many studies have focused on the synergy between different alginate lyases, the synergy between two alginate lyase domains of one alginate lyase has not been reported. Here, we report the synergism between the two catalytic domains of a novel alginate lyase, AlyC6', from the marine alginate-degrading bacterium Vibrio sp. NC2. AlyC6' contains two PL7 catalytic domains (CD1 and CD2) that have no sequence similarity. While both CD1 and CD2 are endo-lyases with the highest activity at 30°C, pH 8.0, and 1.0 M NaCl, they also displayed some different properties. CD1 was PM-specific, but CD2 was PG-specific. Compared with CD2, CD1 had higher catalytic efficiency, but lower substrate affinity. In addition, CD1 had a smaller minimal substrate than CD2, and the products from CD2 could be further degraded by CD1. These distinctions between the two domains enable them to synergize intramolecularly in alginate degradation, resulting in efficient and complete degradation of various alginate substrates. The bioinformatics analysis revealed that diverse alginate lyases have multiple catalytic domains, which are widespread, especially abundant in Flavobacteriaceae and Alteromonadales, which may secret multimodular alginate lyases for alginate degradation. This study provides new insight into bacterial alginate lyases and alginate degradation and is helpful for designing multimodular enzymes for efficient alginate depolymerization. IMPORTANCE Alginate is a major component in the cell walls of brown algae. Alginate degradation is carried out by alginate lyases. Until now, while most characterized alginate lyases contain one single catalytic domain, only a few have been shown to contain two catalytic domains. Furthermore, the synergy of alginate lyases has attracted increasing attention since it plays important roles in microbial alginate utilization and biotechnological applications. Although many studies have focused on the synergy between different alginate lyases, the synergy between two catalytic domains of one alginate lyase has not been reported. Here, a novel alginate lyase, AlyC6', with two functional alginate lyase domains was biochemically characterized. Moreover, the synergism between the two domains of AlyC6' was revealed. Additionally, the distribution of the alginate lyases with multiple alginate lyase domains was investigated based on the bioinformatics analysis. This study provides new insight into bacterial alginate lyases and alginate degradation.


Asunto(s)
Polisacárido Liasas , Vibrio , Secuencia de Aminoácidos , Polisacárido Liasas/metabolismo , Vibrio/metabolismo , Alginatos/metabolismo , Especificidad por Sustrato
4.
J Asian Nat Prod Res ; 24(10): 963-970, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34747287

RESUMEN

A new dihydroflavone, 2(S)-isookanin-4'-methoxy-8-O-ß-D-glucopyranoside (1), and a new polyacetylene glucoside, (10S)-tridecane-2E-ene-4,6,8-triyne-1-ol-10-O-ß-D-glucopyranoside (2), along with seven known compounds (3-9), were isolated from the herb of Bidens parviflora Willd. The structures of all the extracted compounds were elucidated by HR-ESI-MS, 1 D and 2 D NMR spectra, as well as circular dichroism (CD).


Asunto(s)
Bidens , Glucósidos , Glucósidos/química , Polímero Poliacetilénico , Estructura Molecular , Poliinos/química
5.
J Biol Chem ; 295(48): 16380-16392, 2020 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-32967968

RESUMEN

Alginate lyases play important roles in alginate degradation in the ocean. Although a large number of alginate lyases have been characterized, little is yet known about those in extremely cold polar environments, which may have unique mechanisms for environmental adaptation and for alginate degradation. Here, we report the characterization of a novel PL7 alginate lyase AlyC3 from Psychromonas sp. C-3 isolated from the Arctic brown alga Laminaria, including its phylogenetic classification, catalytic properties, and structure. We propose the establishment of a new PM-specific subfamily of PL7 (subfamily 6) represented by AlyC3 based on phylogenetic analysis and enzymatic properties. Structural and biochemical analyses showed that AlyC3 is a dimer, representing the first dimeric endo-alginate lyase structure. AlyC3 is activated by NaCl and adopts a novel salt-activated mechanism; that is, salinity adjusts the enzymatic activity by affecting its aggregation states. We further solved the structure of an inactive mutant H127A/Y244A in complex with a dimannuronate molecule and proposed the catalytic process of AlyC3 based on structural and biochemical analyses. We show that Arg82 and Tyr190 at the two ends of the catalytic canyon help the positioning of the repeated units of the substrate and that His127, Tyr244, Arg78, and Gln125 mediate the catalytic reaction. Our study uncovers, for the first time, the amino acid residues for alginate positioning in an alginate lyase and demonstrates that such residues involved in alginate positioning are conserved in other alginate lyases. This study provides a better understanding of the mechanisms of alginate degradation by alginate lyases.


Asunto(s)
Proteínas Bacterianas/química , Gammaproteobacteria/enzimología , Polisacárido Liasas/química , Multimerización de Proteína , Proteínas Bacterianas/genética , Catálisis , Gammaproteobacteria/genética , Gammaproteobacteria/aislamiento & purificación , Laminaria/microbiología , Polisacárido Liasas/genética , Dominios Proteicos , Relación Estructura-Actividad
6.
Biochem Biophys Res Commun ; 565: 21-28, 2021 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-34090206

RESUMEN

Preoperative anxiety is common and often comes with a higher probability of worse recovery. However, the neurological mechanism of the effect of preoperative anxiety on general anesthesia and subsequent awakening remains unknown. In this study, we report an anxious state results in delayed awakening in anxiety model mice from sevoflurane general anesthesia. More profound inhibition of DA neurons in the VTA contributes to delayed awakening. Optogenetic stimulation of VTA DA neurons can reverse the delay. The results indicate that VTA DA neurons may be involved in the delay in awakening from general anesthesia caused by anxiety.


Asunto(s)
Anestésicos por Inhalación/farmacología , Ansiedad/tratamiento farmacológico , Neuronas Dopaminérgicas/efectos de los fármacos , Sevoflurano/farmacología , Área Tegmental Ventral/efectos de los fármacos , Animales , Femenino , Ratones , Ratones Endogámicos C57BL
7.
Appl Environ Microbiol ; 87(12): e0041221, 2021 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-33771786

RESUMEN

Ulvan is an important marine polysaccharide. Bacterial ulvan lyases play important roles in ulvan degradation and marine carbon cycling. Until now, only a small number of ulvan lyases have been characterized. Here, a new ulvan lyase, Uly1, belonging to polysaccharide lyase family 24 (PL24) from the marine bacterium Catenovulum maritimum, is characterized. The optimal temperature and pH for Uly1 to degrade ulvan are 40°C and pH 9.0, respectively. Uly1 degrades ulvan polysaccharides in the endolytic manner, mainly producing ΔRha3S, consisting of an unsaturated 4-deoxy-l-threo-hex-4-enopyranosiduronic acid and a 3-O-sulfated α-l-rhamnose. The structure of Uly1 was resolved at a 2.10-Å resolution. Uly1 adopts a seven-bladed ß-propeller architecture. Structural and site-directed mutagenesis analyses indicate that four highly conserved residues, H128, H149, Y223, and R239, are essential for catalysis. H128 functions as both the catalytic acid and base, H149 and R239 function as the neutralizers, and Y223 plays a supporting role in catalysis. Structural comparison and sequence alignment suggest that Uly1 and many other PL24 enzymes may directly bind the substrate near the catalytic residues for catalysis, different from the PL24 ulvan lyase LOR_107, which adopts a two-stage substrate binding process. This study provides new insights into ulvan lyases and ulvan degradation. IMPORTANCE Ulvan is a major cell wall component of green algae of the genus Ulva. Many marine heterotrophic bacteria can produce extracellular ulvan lyases to degrade ulvan for a carbon nutrient. In addition, ulvan has a range of physiological bioactivities based on its specific chemical structure. Ulvan lyase thus plays an important role in marine carbon cycling and has great potential in biotechnological applications. However, only a small number of ulvan lyases have been characterized over the past 10 years. Here, based on biochemical and structural analyses, a new ulvan lyase of polysaccharide lyase family 24 is characterized, and its substrate recognition and catalytic mechanisms are revealed. Moreover, a new substrate binding process adopted by PL24 ulvan lyases is proposed. This study offers a better understanding of bacterial ulvan lyases and is helpful for studying the application potentials of ulvan lyases.


Asunto(s)
Alteromonadaceae/enzimología , Polisacárido Liasas/química , Secuencia de Aminoácidos , Catálisis , Filogenia , Polisacárido Liasas/genética , Polisacáridos/química , Especificidad por Sustrato
8.
Pharmacology ; 106(5-6): 323-331, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33780953

RESUMEN

BACKGROUND: Hepatic fibrosis is an inflammatory liver disease, and there is no effective therapy at present. Astilbin is a bioactive ingredient found in many medicinal and food plants, with antioxidative, anti-inflammatory, and antitumor properties. OBJECTIVES: This study aimed to investigate the protective effect and related molecular mechanism of astilbin against carbon tetrachloride (CCl4)-induced liver fibrosis in rats. METHODS: Liver fibrosis was induced by injection of CCl4 in male Sprague-Dawley rats, and those rats were then treated with astilbin at different concentrations. Pathological changes, collagen production, inflammatory cytokine, and oxidative stress were evaluated to evaluate the effects of astilbin on CCl4-induced hepatic fibrosis. Real-time PCR and western blot were performed to detect the mRNA and protein expression of indicated genes. RESULTS: We discovered that CCl4 caused significant fibrosis damage in rat liver, and astilbin dose-dependently improved the liver functions and fibrosis degree. Astilbin treatment significantly decreased collagen production, inflammatory response, and oxidative stress in vivo. Mechanically, administration of astilbin obviously elevated the hepatic levels of Nrf2 and its downstream components, including NAD(P)H:quinone oxidoreductase 1 (Nqo1), heme oxygenase (HO-1), glutamate-cysteine ligase catalytic subunit, and glutamate cysteine ligase modifier. CONCLUSIONS: Taken together, these findings demonstrate that astilbin could protect against CCL4 induced-liver fibrosis in rats.


Asunto(s)
Flavonoles/farmacología , Cirrosis Hepática/prevención & control , Sustancias Protectoras/farmacología , Animales , Tetracloruro de Carbono/toxicidad , Colágeno/metabolismo , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Flavonoles/uso terapéutico , Glutamato-Cisteína Ligasa/metabolismo , Hemo Oxigenasa (Desciclizante)/metabolismo , Inflamación/inducido químicamente , Inflamación/prevención & control , Hígado/efectos de los fármacos , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/patología , Masculino , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo/efectos de los fármacos , Sustancias Protectoras/uso terapéutico , Ratas Sprague-Dawley
9.
J Phys Chem A ; 124(40): 8280-8291, 2020 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-32924506

RESUMEN

The kinetic data of cyclopentadiene C5H6 oxidation reactions are significant for the construction of aromatics oxidation mechanism because cyclopentadiene C5H6 has been proved to be an important intermediate in the aromatics combustion. Kinetics for the elementary reactions on the potential energy surface (PES) relevant for the C5H6 + HO2 reaction are studied in this work. Stationary points on the PES are calculated by employing the CCSD(T)/cc-pVTZ//B3LYP/6-311G(d,p) level of theory. High-pressure limit and pressure-dependent rate constants for elementary reactions on this PES are calculated using conventional transition state theory (TST), variational transition-state theory (VTST) and Rice-Ramsberger-Kassel-Marcus/master equation (RRKM/ME) theory. In this work, the reaction channels for the C5H6 + HO2 reaction, which include H-abstraction channels from C5H6 by HO2 to form the C5H5 + H2O2 and the addition channels through well-skipping pathways to form the bimolecular products C5H7 + O2 or C5H6O + OH, or through C5H7O2 stabilization and its unimolecular decomposition to form the bimolecular products C5H7 + O2 or C5H6O + OH, namely sequential pathways, are studied. Also, the consuming reaction channels for the compounds C5H6O and C5H7 in the addition products are studied. The dominant reaction channels for these reactions are unraveled through comparing the energy barriers and rate constants of all elementary reactions and it is found: (1) HO2 addition to cyclopentadiene C5H6 is more important than direct H-abstraction. (2) in the HO2 addition channels, the well-skipping pathways and sequential pathways are competing and the well-skipping pathways will be favor in the higher pressures and the sequential pathways will be favor in the higher temperature. (3) The major consumption reaction channel for the five-member-ring compound C5H6O is the reaction channel to form C4H6 + CO and the major consumption reaction channel for the five-member-ring compound C5H7 is the reaction channel to form C3H5 + C2H2. High-pressure limit rate constants and pressure-dependent rate constants for elementary reactions on the PES are calculated, which will be useful in modeling the oxidation of aromatic compounds at low- and medium-temperatures.

10.
J Asian Nat Prod Res ; 21(5): 476-493, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-29322879

RESUMEN

Diabetic cardiomyopathy (DCM) is one of the chief diabetes mellitus complications. Inflammation factors may be one reason for the damage from DM. The purpose of this research is to study the potential protective effects of puerarin on DM and the possible mechanisms of action related to NF-κB signal pathway. Following administration of puerarin to the disease model rat, several changes were observed including the changes of serum biochemical index, improved diastolic dysfunction, and enhanced endogenous antioxidant enzymes activities, further NF-κB signaling activation. Puerarin showed cardio-protective effects on DCM by inhibiting inflammation, and it might be a potential candidate for the treatment of DCM.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Cardiomiopatías Diabéticas/prevención & control , Inflamación/tratamiento farmacológico , Isoflavonas/farmacología , Animales , Línea Celular , Células Cultivadas , Glucosa/toxicidad , Isoflavonas/química , Estructura Molecular , Mioblastos Cardíacos/efectos de los fármacos , Miocardio/citología , FN-kappa B , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos
11.
J Phys Chem A ; 122(21): 4869-4881, 2018 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-29757648

RESUMEN

The isodesmic reaction method is applied to calculate the potential energy surface (PES) along the reaction coordinates and the rate constants of the barrierless reactions for unimolecular dissociation reactions of alkanes to form two alkyl radicals and their reverse recombination reactions. The reaction class is divided into 10 subclasses depending upon the type of carbon atoms in the reaction centers. A correction scheme based on isodesmic reaction theory is proposed to correct the PESs at UB3LYP/6-31+G(d,p) level. To validate the accuracy of this scheme, a comparison of the PESs at B3LYP level and the corrected PESs with the PESs at CASPT2/aug-cc-pVTZ level is performed for 13 representative reactions, and it is found that the deviations of the PESs at B3LYP level are up to 35.18 kcal/mol and are reduced to within 2 kcal/mol after correction, indicating that the PESs for barrierless reactions in a subclass can be calculated meaningfully accurately at a low level of ab initio method using our correction scheme. High-pressure limit rate constants and pressure dependent rate constants of these reactions are calculated based on their corrected PESs and the results show the pressure dependence of the rate constants cannot be ignored, especially at high temperatures. Furthermore, the impact of molecular size on the pressure-dependent rate constants of decomposition reactions of alkanes and their reverse reactions has been studied. The present work provides an effective method to generate meaningfully accurate PESs for large molecular system.

12.
J Phys Chem A ; 121(16): 3001-3018, 2017 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-28383903

RESUMEN

Intramolecular H-migration reaction of hydroperoxyalkylperoxy radicals (•O2QOOH) is one of the most important reaction families in the low-temperature oxidation of hydrocarbon fuels. This reaction family is first divided into classes depending upon H atom transfer from -OOH bonded carbon or non-OOH bonded carbon, and then the two classes are further divided depending upon the ring size of the transition states and the types of the carbons from which the H atom is transferred. High pressure limit rate rules and pressure-dependent rate rules for each class are derived from the rate constants of a representative set of reactions within each class using electronic structure calculations performed at the CBS-QB3 level of theory. For the intramolecular H-migration reactions of •O2QOOH radicals for abstraction from an -OOH substituted carbon atom (-OOH bonded case), the result shows that it is acceptable to derive the rate rules by taking the average of the rate constants from a representative set of reactions with different sizes of the substitutes. For the abstraction from a non-OOH substituted carbon atom (non-OOH bonded case), rate rules for each class are also derived and it is shown that the difference between the rate constants calculated by CBS-QB3 method and rate constants estimated from the rate rules may be large; therefore, to get more reliable results for the low-temperature combustion modeling of alkanes, it is better to assign each reaction its CBS-QB3 calculated rate constants, instead of assigning the same values for the same reaction class according to rate rules. The intramolecular H-migration reactions of •O2QOOH radicals (a thermally equilibrated system) are pressure-dependent, and the pressure-dependent rate constants of these reactions are calculated by using the Rice-Ramsberger-Kassel-Marcus/master-equation theory at pressures varying from 0.01 to 100 atm. The impact of molecular size on the pressure-dependent rate constants of the intramolecular H-migration reactions of •O2QOOH radicals has been studied, and it is shown that the pressure dependence of the rate constants of intramolecular H-migration reactions of •O2QOOH radicals decreases with the molecular size at low temperatures and the impact of molecular size on the pressure-dependent rate constants decreases as temperature increases. It is shown that it is acceptable to derive the pressure-dependent rate rules by taking the average of the rate constants from a representative set of reactions with different sizes of the substitutes. The barrier heights follow the Evans-Polanyi relationship for each type of intramolecular hydrogen-migration reaction studied. All calculated rate constants are fitted by a nonlinear least-squares method to the form of a modified Arrhenius rate expression at pressures varying from 0.01 to 100 atm and at the high-pressure limit. Furthermore, thermodynamic parameters for all species involved in these reactions are calculated by the composite CBS-QB3 method and are given in NASA format.

13.
J Asian Nat Prod Res ; 18(6): 562-75, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26898948

RESUMEN

We propose to further research the protective effect of MMI on myocardium ischemic rat model and H9c2 cells that underwent cell apoptosis induced by hypoxia. We established the myocardium ischemic rat model via the cardiac surgical procedures in vivo and treated the model rats with different concentration of MMI. In vitro, with the pretreatment of MMI for 12 h in the model of Na2S2O4-induced hypoxia injury, the H9c2 cells viability was determined by MTT assay. We found that MMI had significantly improved cardiac function of the myocardial ischemia, and significantly decreased the reactive oxygen species level. The expression of P53, Bcl-2, Bax, and caspase-9 was also induced by MMI. In vitro study revealed a concentration-dependent increase in cell viability associated with MMI pretreatment. Annexin V-FITC and PI staining results showed that MMI had a preventive effect on hypoxia-induced apoptosis in H9c2 cells. MMI also inhibited the mitochondrial membrane potential decrease and increased total ATPase activity during hypoxia in H9c2 cells. In conclusion, MMI can enhance the cardiac function in myocardial ischemic rat and increase cell viability and attenuate the apoptosis in H9c2 cells induced by hypoxia, which was associated with inhibiting MMP decreasion and increasing total ATPase activity.


Asunto(s)
Adenosina Trifosfatasas/efectos de los fármacos , Apoptosis/efectos de los fármacos , Isoflavonas/farmacología , Animales , Caspasa 9/metabolismo , Supervivencia Celular/efectos de los fármacos , Isoflavonas/química , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Estructura Molecular , Ratas , Especies Reactivas de Oxígeno/metabolismo
14.
Tumour Biol ; 36(3): 2127-34, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25403884

RESUMEN

MicroRNAs are short regulatory RNAs that play crucial roles in cancer development and progression. MicroRNA-646 (miR-646) is downregulated in many human cancers, and increasing evidence indicates that it functions as a tumor suppressor. However, the role of miR-646 in osteosarcoma remains unclear. Expression levels of miR-646 in osteosarcoma cell lines and patient tissues were evaluated by quantitative real-time PCR (qRT-PCR), and the clinicopathological significance of the resultant data was later analyzed. Next, we investigated the role of miR-646 to determine its potential roles on osteosarcoma cell proliferation, migration, and invasion in vitro. A luciferase reporter assay was conducted to confirm the target gene of miR-646, and the results were validated in the osteosarcoma cell line. In this study, we found that miR-646 was downregulated in osteosarcoma cell lines and osteosarcoma tissues compared with normal osteoblast cell line NHOst and paired adjacent nontumor tissue. We found that a lower expression of miR-646 was associated with metastasis. In osteosarcoma cells, overexpression of miR-646 inhibited cell proliferation, migration, and invasion. In contrast, downregulation of miR-646 expression promoted osteosarcoma cell proliferation, migration, and invasion. Next, we identified that the FGF2 gene is a novel direct target of miR-646 in osteosarcoma cells. Moreover, enforced expression of FGF2 partially reversed the inhibition of cell proliferation, migration, and invasion that was caused by miR-646. Our study demonstrated that miR-646 might be a tumor suppressor in osteosarcoma via the regulation of FGF2, which provided a potential prognostic biomarker and therapeutic target.


Asunto(s)
Neoplasias Óseas/genética , Factor 2 de Crecimiento de Fibroblastos/genética , Genes Supresores de Tumor , MicroARNs/genética , Osteosarcoma/genética , Neoplasias Óseas/patología , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Regulación hacia Abajo , Regulación Neoplásica de la Expresión Génica , Humanos , Invasividad Neoplásica , Osteosarcoma/patología
15.
Org Biomol Chem ; 12(44): 8919-29, 2014 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-25270760

RESUMEN

Five new cardenolide lactates (1­5) and one new dioxane double linked cardenolide glycoside (17) along with 15 known compounds (6­16 and 18­21) were isolated from the ornamental milkweed Asclepias curassavica. Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D- and 2D-NMR). The molecular structures and absolute configurations of 1­3 and 17 were further confirmed by single-crystal X-ray diffraction analysis. Simultaneous isolation of dioxane double linked cardenolide glycosides (17­21) and cardenolide lactates (1­5) provided unique chemotaxonomic markers for this genus. Compounds 1­21 were evaluated for the inhibitory activities against DU145 prostate cancer cells. The dioxane double linked cardenolide glycosides showed the most potent cytotoxic effect followed by normal cardenolides and cardenolide lactates, while the C21 steroids were non-cytotoxic. Enzymatic assay established a correlation between the cytotoxic effects in DU145 cancer cells and the Ki for the inhibition of Na(+),K(+)-ATPase. Molecular docking analysis revealed relatively strong H-bond interactions between the bottom of the binding cavity and compounds 18 or 20, and explained why the dioxane double linked cardenolide glycosides possessed higher inhibitory potency on Na(+),K(+)-ATPase than the cardenolide lactate.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Asclepias/química , Cardenólidos/farmacología , Inhibidores Enzimáticos/farmacología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Cardenólidos/química , Cardenólidos/aislamiento & purificación , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/aislamiento & purificación , Humanos , Modelos Moleculares , Conformación Molecular , Estructura Molecular , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Relación Estructura-Actividad
16.
J Hazard Mater ; 445: 130537, 2023 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-36493640

RESUMEN

Recently, hydroxylamine (HAm) was introduced to drive advanced oxidation processes (AOPs) for removing organic contaminants. However, we found that HAm-driven Cu(II)/peroxymonosulfate oxidation of phenol produced p-nitrosophenol, 2-nitrophenol and 4-nitrophenol. The total nitro(so) products accounted for approximately 25.0 % of the phenol transformation at certain condition. SO4•- and •OH were identified as the primary and second significant oxidants, respectively. Reactive nitrogen species (RNS) were involved in phenol transformation. The pathway and mechanism of HAm transformation in HAm-driven transition metal ion-catalyzed AOPs were proposed for the first time in this study. The product of HAm via twice single-electron oxidation by Cu(II) is nitroxyl (HNO/NO-), which is a critical oxidation intermediate of HAm. Further oxidation of HNO by SO4•- or •OH is the initial step in propagating radical chain reactions, leading to nitric oxide radical (•NO) and nitrogen dioxide radical (•NO2) as the primary RNS. HAm is a critical intermediate in natural nitrogen cycle, suggesting that HAm can drive the oxidation processes of pollutants in natural environments. Nitro(so) products will be readily produced when AOPs are applied for ecological remediation. This study highlights the formation of toxic nitrosated and nitrated products in HAm-driven AOPs, and the requirement of risk assessments to evaluate the possible health and ecological impacts.


Asunto(s)
Nitratos , Contaminantes Químicos del Agua , Hidroxilamina , Oxidación-Reducción , Óxido Nítrico , Fenol , Hidroxilaminas , Contaminantes Químicos del Agua/análisis
17.
Zhong Xi Yi Jie He Xue Bao ; 10(4): 384-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22500711

RESUMEN

BACKGROUND: Hyperplastic disease of the breast (HDB) is caused by a hormone imbalance experienced among women at a certain age. Slight breast pain is common in women before menstruation without need of treatment; however, if the pain becomes severe, it can cause physical and mental suffering. Therefore, it is of great clinical significance to control this disease. METHODS AND DESIGN: This study will follow the principle of evidence-based medicine and adopt various design methods, being conducted as a randomized, controlled, double-blind and multicenter trial based on the cause of HDB defined in Chinese and Western medicine. According to the cause of HDB in Chinese and Western medicine and its pathogenesis and prognosis, this study will conduct syndrome differentiation, adopt external therapy of Chinese medicine by using Sanjie Zhitong plaster as the intervention, take placebo as the control method and aim at relieving pain. The effectiveness and safety of Chinese medicine therapy will be evaluated. During the design process, some confounding factors will be taken into consideration and prevented with corresponding measures. We will also discuss the side effects of the medicine used and corresponding countermeasures to be taken. DISCUSSION: On the basis of traditional Chinese medicine (TCM) theory, Sanjie Zhitong plaster takes the advantage of external therapy of TCM. According to the main etiology and pathogenesis of HDB, the treatment principles of warming the meridians and activating blood, smoothing circulation and relieving pain, and removing swelling and dissipating stagnation are put forward. The medicine exerts its effects directly on the lesion site by permeating into the skin and stimulating the meridians, thus improving blood supply to the breast and relieving pain.


Asunto(s)
Medicamentos Herbarios Chinos/administración & dosificación , Enfermedad Fibroquística de la Mama/terapia , Medicina Tradicional China/métodos , Manejo del Dolor/métodos , Dolor/tratamiento farmacológico , Método Doble Ciego , Femenino , Humanos
18.
Environ Sci Pollut Res Int ; 29(48): 73326-73340, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35624367

RESUMEN

The main chemical component of high-silicon iron tailings (HSITs) is SiO2; HSITs also include some oxides such as Al2O3 and CaO. Mechanical activation can reduce the particle size of HSITs and enhance their pozzolanic activity such that they can be used as a type of mineral admixture for cement-based materials (CBMs). This study aims to investigate the mechanical activation (ultrafine grinding) effects of HSITs, including physical and crystallization structure effects. The particle distribution, specific surface area, density, and solubility of HSITs were tested using laser particle size analysis and other routine physical testing methods. Their crystal structures were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry-thermogravimetry (DSC-TG). Grinding reduced the particle size of HSIT particles and increased their specific surface area, wherein the minimum D50 was 5.75 µm, the maximum specific surface area was 7608 m2/kg, and the corresponding grinding time was 3.5 h. With an increase in grinding time, the solubility showed an increasing trend; however, the density showed a decreasing trend. The change was fast before 3.5 h or 4 h and then slowed down, but the final solubility was still higher than its initial level, while the final density was still lower than its initial level. Grinding reduced the degree of crystallization of the minerals in HSITs and increased the microscopic strain and disorder of its crystal structure. These changes were significant for a grinding time of 0-3.5 h, after which the changes tended to be slow. The symmetry and integrity of the SiO2 structure decreased with grinding. The activity index of the HSIT powder was higher than 0.6. Ultrafine grinding improves the particle size distribution of HSITs and reduces the crystallinity of their main minerals, which in turn increases their chemical reactivity. It can be said that ultra-finely ground HSIT powder is pozzolanic and can be used as a mineral admixture for CBMs, and its grinding limit can be inferred to be 3.5 h.


Asunto(s)
Hierro , Dióxido de Silicio , Silicio , Hierro/química , Tamaño de la Partícula , Polvos , Silicio/química , Dióxido de Silicio/química , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X
19.
World J Clin Cases ; 9(27): 8249-8259, 2021 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-34621888

RESUMEN

BACKGROUND: Granulomatous lobular mastitis (GLM) is a type of benign chronic inflammatory disease that poses therapeutic challenges to healthcare providers. The diagnosis of GLM relies on tissue biopsy, and incorrect treatment may lead to delayed diagnosis, considerable aesthetic damage, and even mastectomy. CASE SUMMARY: We report the case of a 37-year-old Chinese woman who was lactating and had GLM in both breasts. At the time of treatment, the right breast had a mass of approximately 15 cm × 11 cm, which was hard and had poor mobility. Multiple skin ulcerations and pus spills were also observed on the surface of the breast. The left breast had a mass of about 13 cm × 9 cm, which was hard and had poor mobility. CONCLUSION: Herein, we report a case of bilateral GLM in a lactating woman that was successfully treated with traditional Chinese medicine (TCM), without the requirement for surgery or other treatments. Therefore, TCM may have advantages in the nonsurgical treatment of GLM.

20.
Zhonghua Nei Ke Za Zhi ; 49(1): 19-23, 2010 Jan.
Artículo en Zh | MEDLINE | ID: mdl-20356475

RESUMEN

OBJECTIVE: To explore the impact of genetic background on pancreatic beta-cell first-phase secretion function with L-arginine (L-ARG) stimulation test. METHODS: Plasma insulin level was detected in 201 cases before and after L-ARG stimulation test. Among them, 61 cases were newly diagnosed type 2 diabetic patients with family history of diabetes (FH+DM), 55 newly diagnosed type 2 diabetic patients without family history of diabetes (FH-DM), 31 with normal glucose tolerance and family history of diabetes (FH+) 54 with normal glucose tolerance but without family history of diabetes (FH-). Homeostasis model assessment (HOMA) was used to estimate insulin resistance (HOMA-IR). RESULTS: It was premised that gender, age and BMI were similar among the 4 groups. (1) TC, TG, fasting plasma glucose, 2h plasma glucose, fasting insulin and HOMA-IR in the two groups of newly diagnosed type 2 diabetic patients with or without family history of diabetes were significantly higher than those in the two groups of normal glucose tolerance with or without family history of diabetes. The multiples of the peak level and the base level of insulin secretion in the groups of newly diagnosed diabetes were significantly lower than those in the groups of normal glucose tolerance with and without family history (P < 0.05). (2) Insulin secretion reached a peak in 2 minutes and started to decline in 4 minutes in all the four groups. (3) The multiples of the peak level and the base level of insulin secretion in normal glucose tolerance group with family history of diabetes were 20.8% lower than those in the group without family history, being 7.27 and 9.18 respectively (P < 0.05). (4) Two-minute peak insulin secretion, HOMA-IR and age in the newly diagnosed type 2 diabetic group with family history of diabetes was significantly lower than these in the group without family history (P < 0.05). The multiples of the peak level and the base level of insulin secretion in the newly diagnosed type 2 diabetic group with family history of diabetes and that group without family history were 5.18 and 5.31 respectively and there was no significant difference between the two groups (P > 0.05). (5) When the normal glucose tolerance subjects with family history of diabetes progressed to suffer from diabetes, the multiples of the peak level and the base level of insulin secretion declined 43.6% (P < 0.05) more than those in the subjects still with normal glucose tolerance without family history. CONCLUSION: In the early course of diabetes, insulin resistance dose not function significantly, but genetic background make the first-phase secretory function of the beta-cell to decline gradually and type 2 diabetes occurs easily. In the absence of genetic background, insulin resistance makes first-phase the secretion of insulin to decline relatively slow.


Asunto(s)
Diabetes Mellitus Tipo 2 , Glucosa , Arginina , Diabetes Mellitus Tipo 2/sangre , Antecedentes Genéticos , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Islotes Pancreáticos
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