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1.
Ecotoxicol Environ Saf ; 281: 116639, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38964069

RESUMEN

Hexavalent chromium [Cr(VI)] exists widely in occupational environments. The mechanistic target of rapamycin (mTOR) has been well-documented to regulate autophagy negatively. However, we found that low concentration of Cr(VI) (0.2 µM) elevated both mTOR and autophagy and promote cell survival. Conversely, high concentration of Cr(VI) (6 µM) caused cell death by inhibiting mTOR and subsequently inducing autophagy. Tunicamycin (Tm), as an Endoplasmic reticulum (ER) stress activator was used to induce mild ER stress at 0.1 µg/ml and it activated both autophagy and mTOR, which also caused cell migration in a similar manner to that observed with low concentration of Cr(VI). Severe ER stress caused by Tm (2 µg/ml) decreased mTOR, increased autophagy and then inhibited cell migration, which was the same as 6 µM Cr(VI) treatment, although Cr(VI) in high concentration inhibited ER stress. Activating transcription factor 4 (ATF4), a downstream target of ER stress, only increased under mild ER stress but decreased under severe ER stress and 6 µM Cr(VI) treatment. Chromatin immunoprecipitation (ChIP) experiment indicated that ATF4 could bind to the promoter of ATG4B and AKT1. To sum up, our data revealed that mild ER stress induced by low concentration of Cr(VI) could enhance transcriptional regulation of ATG4B and AKT1 by ATF4, which induced both autophagy and mTOR to promote cell viability.


Asunto(s)
Factor de Transcripción Activador 4 , Autofagia , Cromo , Estrés del Retículo Endoplásmico , Serina-Treonina Quinasas TOR , Estrés del Retículo Endoplásmico/efectos de los fármacos , Cromo/toxicidad , Autofagia/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Factor de Transcripción Activador 4/metabolismo , Humanos , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Tunicamicina/farmacología , Tunicamicina/toxicidad
2.
Ecotoxicol Environ Saf ; 272: 116076, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38335577

RESUMEN

Cr(VI) is known to be seriously toxic and carcinogenic. Hypoxia-inducible factor-1α (HIF-1α) is a crucial regulator to promote tumor development. In this study, we found that Cr(VI) significantly increased the expression of HIF-1α in A549 cells and in lung of BALB/c mice but not in HELF cells. Treatment with Lificiguat (YC-1), HIF-1α inhibitor, or CoCl2, HIF-1α inducer, could alter Cr(VI)-induced autophagy, glycolysis, and cell growth in A549 cells but not in HELF cells, validating the involvement of HIF-1α in these effects of Cr(VI) in A549 cells. Co-treatments of pcATG4B with YC-1, or siATG4B with CoCl2 demonstrated the role of HIF-1α / autophagy axis in inducing glycolysis and cell growth in A549 cells. In HELF cells, however, only autophagy but not HIF-1α played a role in inducing glycolysis. The protein level of p53 was significantly lower in A549 cells than in HELF cells. RITA, a p53 inducer, attenuated Cr(VI)-induced HIF-1α and LC3-II in A549 cells, suggesting that p53 might be the mechanism underlying the different effects of Cr(VI) on HIF-1α in A549 and HELF cells. Thus, p53-dependent HIF-1α / autophagy-mediated glycolysis plays a role in facilitating Cr(VI)-induced carcinogenesis.


Asunto(s)
Carcinogénesis , Cromo , Cobalto , Proteína p53 Supresora de Tumor , Animales , Ratones , Proteína p53 Supresora de Tumor/genética , Autofagia , Movimiento Celular , Glucólisis , Línea Celular Tumoral
3.
Phytother Res ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38973314

RESUMEN

Tamarixetin, a natural dietary flavone, exhibits remarkable potential for the treatment of ischemic stroke. The present article aimed to explore the impact of tamarixetin on ischemic stroke and elucidate the underlying mechanisms. Effects of tamarixetin on ischemic stroke were evaluated in rats using the middle cerebral artery occlusion and reperfusion (MCAO/R) model, by assessing the neurological deficit scores, brain water content, brain infraction, and neuronal damage. The levels of proinflammatory cytokines, NLRP3 inflammasome activation, reactive oxygen species (ROS) production, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression were measured in MCAO/R rats and lipopolysaccharide-stimulated cells. Tamarixetin administration improved the neurological dysfunction and neuronal loss in MCAO/R rats. In addition, tamarixetin reduced microglial hyperactivation and proinflammatory cytokines expression in vivo and in vitro. Tamarixetin attenuated NF-κB p65 phosphorylation and promoter activity, reduced NLRP3 expression and caspase-1 cleavage, and downregulated IL-1ß and IL-18 secretions to suppress NLRP3 inflammasome activation. The levels of superoxide anion, hydrogen peroxide, and ROS were also suppressed by tamarixetin. The downregulation of NADP+ and NADPH levels, and gp91phox expression indicated the ameliorative effects of tamarixetin on NADPH oxidase activation. In the gp91phox knockdown cells treated with lipopolysaccharide, the effects of tamarixetin on NADPH oxidase activation, ROS generation, and NLRP3 inflammasome activation were diminished. Moreover, tamarixetin protects neurons against microglial hyperactivation in vitro. Our findings support the potential of tamarixetin as a therapeutic agent for ischemic stroke, and its mechanism of action involves the inhibition of NADPH oxidase-NLRP3 inflammasome signaling.

4.
J Environ Manage ; 359: 121045, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38703653

RESUMEN

A multifunctional Ag/AlOOH nanowires (ANW) composite substrate was constructed, which not only accomplishes highly sensitive detection of organic dye molecules, but also has excellent performance in the degradation of pollutants. The ANW in the Ag/ANW substrate possesses a high aspect ratio, which extends the distribution area of Ag and enables a large number of hot spots on the active substrate. Additionally, due to the abundant OH groups on the ANW, there is an increased number of anchor sites for adsorbed metal ions in the Ag/ANW compound, thus contributing to the enhancement and degradation of molecules. Moreover, the constructed multifunctional Ag/ANW nanocomplexes also show great promise for practical applications, providing a reference for the detection and degradation of contaminants.


Asunto(s)
Nanocables , Espectrometría Raman , Nanocables/química , Plata/química , Compuestos Orgánicos/química , Compuestos Orgánicos/análisis
5.
Inorg Chem ; 62(9): 3916-3928, 2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36821293

RESUMEN

Non-heterocyclic N-donor nitrilotriacetate-derived triamide ligands are one of the most promising extractants for the selective extraction separation of trivalent actinides over lanthanides, but the thermodynamics and mechanism of the complexation of this kind of ligand with actinides and lanthanides are still not clear. In this work, the complexation behaviors of N,N,N',N',N″,N″-hexaethylnitrilotriacetamide (NTAamide(Et)) with four representative trivalent lanthanides (La3+, Nd3+, Eu3+, and Lu3+) were systematically investigated by using 1H nuclear magnetic resonance (1H NMR), ultraviolet-visible (UV-vis) and fluorescence spectrophotometry, microcalorimetry, and single-crystal X-ray diffractometry. 1H NMR spectroscopic titration of La3+ and Lu3+ indicates that two species of 1:2 and 1:1 metal-ligand complexes were formed in NO3- and ClO4- media. The stability constants of NTAamide(Et) with Nd3+ and Eu3+ obtained by UV-vis and fluorescence titration show that the complexing strength of NTAamide(Et) with Nd3+ is lower than that with Eu3+ in the same anionic medium, while that of the same lanthanide complex is higher in ClO4- medium than in NO3- medium. Meanwhile, the formation reactions for all metal-ligand complexes are driven by both enthalpy and entropy. The structures of lanthanide complexes in the single ClO4- and NO3- medium and the mixed one were determined to be [LnL2(MeOH)](ClO4)3 (Ln = La, Nd, Eu, and Lu), [LaL2(EtOH)2][La(NO3)6], and [LaL2(NO3)](ClO4)2, separately. The average bond lengths of lanthanide complexes decrease gradually with the decrease in ionic radii of Ln3+, indicating that heavier lanthanides form stronger complexes due to the lanthanide contraction effect, which coincides with the trend of the complexing strength obtained by spectroscopic titration. This work not only reveals the thermodynamics and mechanism of the complexation between NTAamide ligands and lanthanides but also obtains the periodic tendency of complexation between them, which may facilitate the separation of trivalent lanthanides from actinides.

6.
J Biochem Mol Toxicol ; 37(10): e23446, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37354072

RESUMEN

Breast cancer (BC) with high HER2 expression has higher recurrence rate and worse prognosis, and its immunotherapy is promising. Based on the high expression of HER2, develop Chimeric Antigen Receptor T-cell (CAR-T) and PDL-1 immunotherapy, and study the molecular pathways of related immune cells and recurrence. HER2-CAR-T cells were constructed using retroviruses, and their specific recognition and immune effects on HER2+ BC cells were verified by in vivo and in vitro experiments. PDL-1 was used as adjuvant immunotherapy, knocking down PDL-1 in tumor cells or dendritic cells, or depleted macrophages to study immune pathways. The negative regulation of HER2 by cbl was determined by IP, ubiquitination experiments, and segmented plasmids, elucidating the molecular mechanism of HER2+ BC recurrence after immunotherapy. HER2-CAR-T specifically recognizes HER2-positive tumor cells and inhibits tumor growth in vivo and in vitro, and anti-PDL1 treatment enhances the therapeutic effect of HER2-CAR-T on tumors. HER2-CART therapy eradicated solid tumors after PDL1 knockdown in dendritic cells. Immunotherapy of relapsed tumors lost HER2 expression by upregulating cbl. HER2-CAR-T shows specific recognition of HER2+ cells and can mediate immune response therapy with the cooperation of PDL-1.

7.
Bioorg Chem ; 139: 106717, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37454495

RESUMEN

1H NMR-guided fractionation led to the isolation of 16 alkaloids from the alkaloidal extract of Stephania longa, including 11 new hasubanan alkaloids (1-11) and five known alkaloids (12-16). Interestingly, compounds 2 and 11 are typically considered protonated tertiary amine compounds, whereas compounds 1 and 10 are regarded as oxidized versions of the corresponding compounds. Their gross structures were determined through an extensive analysis of spectroscopic data (NMR (nuclear magnetic resonance) and HRESIMS (high resolution electrospray ionization mass spectroscopy)), and their absolute configurations were established by comparing their experimental and calculated electronic circular dichroism (ECD) spectra. The new (3) and a known (12) compounds in all isolates displayed stronger antineuroinflammatory effects (IC50 values of 1.8 and 11.1 µM, respectively) than minocycline (IC50 value of 15.5 µM) against NO production on LPS-activated BV2 cells.


Asunto(s)
Alcaloides , Antineoplásicos , Stephania , Stephania/química , Espectroscopía de Protones por Resonancia Magnética , Alcaloides/farmacología , Alcaloides/química , Espectroscopía de Resonancia Magnética , Extractos Vegetales , Estructura Molecular
8.
Phytother Res ; 37(9): 3982-4001, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37209001

RESUMEN

Alzheimer's disease (AD) is the most frequent cause of dementia in the elderly. Isoamericanin A (ISOA) is a natural lignan possessing great potential for AD treatment. This study investigated the efficacy of ISOA on memory impairments in the mice intrahippocampal injected with lipopolysaccharide (LPS) and the underlying mechanism. Y-maze and Morris Water Maze data suggested that ISOA (5 and 10 mg/kg) ameliorated short- and long-term memory impairments, and attenuated neuronal loss and lactate dehydrogenase activity. ISOA exerted anti-inflammatory effect demonstrating by the reduction of ionized calcium-binding adapter molecule 1 positive cells and suppression of marker protein and pro-inflammation cytokines expressions induced by LPS. ISOA suppressed the nuclear factor kappa B (NF-κB) signaling pathway by inhibiting IκBα phosphorylation and NF-κB p65 phosphorylation and nuclear translocation. ISOA inhibited superoxide and intracellular reactive oxygen species accumulation by reducing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, demonstrating by suppressing NADP+ and NADPH contents, gp91phox expression, and p47phox expression and membrane translocation. These effects were enhanced in combination with NADPH oxidase inhibitor apocynin. The neuroprotective effect of ISOA was further proved in the in vitro models. Overall, our data revealed a novel pharmacological activity of ISOA: ameliorating memory impairment in AD via inhibiting neuroinflammation.


Asunto(s)
Lipopolisacáridos , FN-kappa B , Ratones , Animales , FN-kappa B/metabolismo , Lipopolisacáridos/farmacología , NAD/metabolismo , NAD/farmacología , NADP/metabolismo , NADP/farmacología , Transducción de Señal , NADPH Oxidasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Trastornos de la Memoria
9.
BMC Microbiol ; 22(1): 246, 2022 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-36221067

RESUMEN

BACKGROUND: Azolla is a small floating fern living in symbiosis with nitrogen-fixing cyanobacteria and provides a variety of important ecosystem benefits. Previous studies have presented that Azolla harbors diverse bacteria that may play a key role in host fitness and productivity. However, the characteristics of endophytic bacteria inhabiting the phyllosphere of different species of Azolla have not yet been fully understood. RESULTS: In this study, the 16S ribosomal DNA (rDNA) V5-V7 region of bacteria was determined by Illumina high-throughput sequencing platform to study the diversity and richness of endophytic bacterial communities in the phyllosphere of five Azolla species collected from different countries. A total of 1150 operational taxonomic units (OTUs) were detected for the endophytic bacteria community. According to the α diversity indices, the diversity of bacteria was ordered as Azolla imbricata > A. pinnata > A. filiculoides > A. mexicana > A. caroliniana. The PCoA results displayed that the bacterial communities of A. mexicana and A. caroliniana shared the highest similarity, followed by the similarity between A. pinnata and A. imbricata, and they were significantly distinct from the community of A. filiculoides. The dominant bacteria of Azolla mainly belonged to the phylum of Proteobacteria, followed by Actinobacteria, Chlorobillobacteria, and Firmicutes. In detail, the relative abundance of Proteobacteria in A. imbricata was 52.23%, whereas it was more than 80.00% in the other four species of Azolla. Notably, Herbaspirillum (45.91%, 44.08%) and Methylophilus (29.97%, 37.96%) were the main genera inhabiting A. mexicana and A. caroliniana respectively. Ferrovibrio (18.54%) and Rhizobium (16.68%) were the dominant genera inhabiting A. filiculoides. The group of unidentified genera (41.63%, 44.92%) consisted most of the bacteria in A. imbricata and A. pinnata respectively. Further analysis suggested that the significant different bacteria identified in LDA Effect Size analysis existed Azolla species-specific patterns. CONCLUSIONS: In summary, all results suggested that the diversity and composition of the endophytic bacterial communities were different in Azolla species.


Asunto(s)
Cianobacterias , Helechos , Cianobacterias/genética , ADN Ribosómico/genética , Ecosistema , Helechos/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Nitrógeno , Proteobacteria/genética , ARN Ribosómico 16S/genética
10.
New Phytol ; 236(4): 1310-1325, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35975703

RESUMEN

Plant cells continuously experience mechanical stress resulting from the cell wall that bears internal turgor pressure. Cortical microtubules align with the predicted maximal tensile stress direction to guide cellulose biosynthesis and therefore results in cell wall reinforcement. We have previously identified Increased Petal Growth Anisotropy (IPGA1) as a putative microtubule-associated protein in Arabidopsis, but the function of IPGA1 remains unclear. Here, using the Arabidopsis cotyledon pavement cell as a model, we demonstrated that IPGA1 forms protein granules and interacts with ANGUSTIFOLIA (AN) to cooperatively regulate microtubule organisation in response to stress. Application of mechanical perturbations, such as cell ablation, led to microtubule reorganisation into aligned arrays in wild-type cells. This microtubule response to stress was enhanced in the IPGA1 loss-of-function mutant. Mechanical perturbations promoted the formation of IPGA1 granules on microtubules. We further showed that IPGA1 physically interacted with AN both in vitro and on microtubules. The ipga1 mutant alleles exhibited reduced interdigitated growth of pavement cells, with smooth shape. IPGA1 and AN had a genetic interaction in regulating pavement cell shape. Furthermore, IPGA1 genetically and physically interacted with the microtubule-severing enzyme KATANIN. We propose that the IPGA1-AN module regulates microtubule organisation and pavement cell shape.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Katanina/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Forma de la Célula , Anisotropía , Microtúbulos/metabolismo , Proteínas Asociadas a Microtúbulos/genética , Celulosa/metabolismo , Proteínas Represoras/metabolismo
11.
Inorg Chem ; 61(16): 6063-6072, 2022 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-35420792

RESUMEN

Comparatively revealing the complexation behavior of trivalent actinides and lanthanides with functional ligands in aqueous solution is of great importance to enrich our knowledge on the fundamental coordination chemistry of trivalent f-block elements and to control the fate of minor actinides in nuclear fuel cycles. In this work, the complexation of Am(III) and Nd(III), representatives for trivalent actinides and lanthanides, respectively, with a N,O-hybrid ligand 6-(dimethylcarbamoyl)picolinic acid (DMAPA, denoted as HL) was investigated by absorption spectroscopy, calorimetry, X-ray crystallography, and density functional theory (DFT) calculations. Successive formation of 1:1, 1:2, and 1:3 (metal/ligand) complexes of Am(III) and Nd(III) with DMAPA was identified, and the corresponding thermodynamic parameters were determined. The binding strength of Am(III) with DMAPA is slightly stronger than that of Nd(III), and the complexation of Nd(III) with DMAPA is mainly entropy-driven. The crystal structure of the 1:2 Nd(III)/DMAPA complex and the DFT calculation shed additional light on the coordination and structural characteristics of the complexes. In contrast to the Nd-N bond in the Nd(III)/DMAPA complex, the Am-N bond in the Am(III)/DMAPA complex exhibits more covalency, which contributes to the slightly stronger complexation of Am(III) with DMAPA.

12.
Phys Chem Chem Phys ; 24(42): 25950-25961, 2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36263674

RESUMEN

Herein, we report a four-step mechanism for the spontaneous multi-scale supramolecular assembly (MSSA) process in a two-phase system concerning an ionic liquid (IL). The complex ions, elementary building blocks (EBBs), [EBB]n clusters and macroscopic assembly (MA) sphere are formed step by step. The porous large-sized [EBB]n clusters in the glassy state can hardly stay in the IL phase and they transfer to the IL-water interface due to both electroneutrality and amphiphilicity. Then, the clusters undergo random collision in the interface driven by the Marangoni effect and capillary force thereafter. Finally, a single MA sphere can be formed owing to supramolecular interactions. To our knowledge, this is the first example realizing spontaneous whole-process supramolecular assembly covering microscopic, mesoscopic and macroscopic scales in extraction systems. The concept of multi-scale selectivity (MSS) is therefore suggested and its mechanism is revealed. The selective separation and solidification of metal ions can be realized in a MSSA-based extraction system depending on MSS. In addition, insights into the physicochemical characteristics of ILs from microscopic, mesoscopic to macroscopic scales are provided, and especially, the solvation effect of ILs on the large-sized clusters leading to the phase-splitting is examined. It is quite important that the polarization of uranyl in its complex, the growing of uranyl clusters in an IL as well as the glassy material of uranyl are investigated systematically on the basis of both experiment and theoretical calculations in this work.

13.
Inorg Chem ; 60(5): 3139-3148, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33576608

RESUMEN

The complexation of cerium with glutarimidedioxime (H2L) was studied by potentiometry, ESI-mass spectrometry, and cyclic voltammetry. Crystallization of [CeIV(HL)3]+ from Ce3+ starting reactant indicated spontaneous complexation-driven oxidation. In aqueous solution, Ce3+ ions form three successive complexes, Ce(HL)2+, Ce(HL)2+, and Ce(HL)3 (where HL- stands for the singly deprotonated ligand). The interactions of glutarimidedioxime with metal ions are dominantly electrostatic in nature, and the stability constants of the complexes are correlated to the charge density of metal ions. Extrapolations of predicted stability constant (log ß) values were made from plotting effective charge and the ionic radius of the metal ion for Pu3+ and Pu4+. The stability constants of PuIV(HL)3+ and PuIII(HL)2+ are estimated to be 27.74 and 19.75, respectively. The differences of stability constants mean that glutarimidedioxime selectively binds Pu4+ over Pu3+ by a factor of about 8 orders of magnitude, suggesting Pu4+ would be stabilized by chelation with glutarimidedioxime. The mechanism of reduction of Pu4+ to Pu3+ in acidic solution is explained by decomposition of glutarimidedioxime through acid hydrolysis rather than a chelation-driven mechanism.

14.
Bioorg Chem ; 107: 104597, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33450546

RESUMEN

Stephania epigaea H. S. Lo is a folk medicine widely distributed in the south of China, especially in Yunnan and Guangxi province. An in vitro anti-neuroinflammatory study showed that total alkaloids of it can potently inhibit LPS-induced NO releasing of BV2 cells with an IC50 value of 10.05 ± 2.03 µg/mL (minocycline as the positive drug, IC50 15.49 ± 2.14 µM). The phytochemical investigation of the total alkaloids afforded three new phenanthrene (1-3), two lactams (4a, 4b), and nine aporphine derivatives (5-13). The final structure of 1 was identified by computer-assisted structure elucidation (ACD/Structure Elucidator software and the 13C NMR calculation with GIAO method) due to many possibilities of the substituent pattern. All isolates were evaluated for their anti-neuroinflammatory effects, and as a result, 5, 8, 10, and 11 exhibited stronger inhibitory activities than the minocycline. The results suggested S. epigaea could provide potential therapeutic agents for neurodegenerative diseases.


Asunto(s)
Antiinflamatorios/farmacología , Productos Biológicos/farmacología , Inflamación/tratamiento farmacológico , Fitoquímicos/farmacología , Stephania/química , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Línea Celular , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Estructura Molecular , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación , Relación Estructura-Actividad
15.
PLoS Genet ; 14(10): e1007705, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30296269

RESUMEN

Plants have evolved diverse cell types with distinct sizes, shapes, and functions. For example, most flowering plants contain specialized petal conical epidermal cells that are thought to attract pollinators and influence light capture and reflectance, but the molecular mechanisms controlling conical cell shaping remain unclear. Here, through a genetic screen in Arabidopsis thaliana, we demonstrated that loss-of-function mutations in ANGUSTIFOLIA (AN), which encodes for a homolog of mammalian CtBP/BARs, displayed conical cells phenotype with wider tip angles, correlating with increased accumulation of reactive oxygen species (ROS). We further showed that exogenously supplied ROS generated similar conical cell phenotypes as the an mutants. Moreover, reduced endogenous ROS levels resulted in deceased tip sharpening of conical cells. Furthermore, through enhancer screening, we demonstrated that mutations in katanin (KTN1) enhanced conical cell phenotypes of the an-t1 mutants. Genetic analyses showed that AN acted in parallel with KTN1 to control conical cell shaping. Both increased or decreased ROS levels and mutations in AN suppressed microtubule organization into well-ordered circumferential arrays. We demonstrated that the AN-ROS pathway jointly functioned with KTN1 to modulate microtubule ordering, correlating with the tip sharpening of conical cells. Collectively, our findings revealed a mechanistic insight into ROS homeostasis regulation of microtubule organization and conical cell shaping.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/citología , Forma de la Célula/fisiología , Proteínas Represoras/genética , Arabidopsis/fisiología , Células Epidérmicas/metabolismo , Epidermis/metabolismo , Flores/genética , Flores/metabolismo , Katanina/genética , Microtúbulos/genética , Especies Reactivas de Oxígeno/metabolismo
16.
J Nat Prod ; 83(4): 864-872, 2020 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-32129063

RESUMEN

Six new (1-6) and two known (7, 8) alkaloids that were chemically inseparable geometrical isomers (two isomers present in a 1:1 ratio for 1-4 and 6 and a 1:3 ratio for 5, 7, and 8) were identified from Stephania cepharantha. Their structures and absolute configurations were determined by spectroscopic data analyses and comparison of their experimental and calculated ECD spectra. Moreover, using NOE correlations and DFT-based calculations, the NMR data of each geometrical isomer of 1-6 were assigned. The biological evaluation of 1-8 showed that 5 and 6 have stronger inhibitory effects (IC50 values, 12.0 and 12.6 µM, respectively) than minocycline (IC50 value, 17.5 µM) against NO production in overactivated BV2 cells, suggesting they have great potential in the development of neuroinflammatory therapeutics for treating neurodegenerative diseases.


Asunto(s)
Alcaloides/química , Alcaloides/farmacología , Amidas/química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Iminas/química , Isoquinolinas/química , Isoquinolinas/farmacología , Stephania/química , Animales , Línea Celular , Supervivencia Celular , Dicroismo Circular , Isomerismo , Espectroscopía de Resonancia Magnética , Ratones , Estructura Molecular , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis
17.
Bioorg Chem ; 97: 103715, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32146172

RESUMEN

Neuroinflammation are involved in the pathogenesis of many neurodegenerative disorders. In our screening of natural effective neuroinflammatory inhibitors from natural products, stilbenes, such as resveratrol and its analogues, have received considerable attention over the last several decades as anti-neuroinflammatory agents. Then, Bletilla striata attracted our attention due to its abundant stilbenes portion, PE fraction. So, three new stilbenes: dusuanlansin E1 (23a), dusuanlansin E2 (23b), 3-hydroxy-5-methoxybibenzyl-3'-O-ß-d-glucopyranoside (27), and 30 known stilbene compounds were isolated from B. striata. These structures of the compounds were established on the basis of extensive spectroscopic analysis including 1D and 2D NMR and circular dichroism (CD) data. Furthermore, all the isolated components were tested in vitro for their inhibitory effects on the nitric oxide generation in LPS-stimulated BV2 cells. As a result, compounds 2, 5, 6, 16, 17 can greatly inhibit the NO production without cytotoxicity. In addition, SARs between stilbenes and anti-neuroinflammation effects were discussed briefly. In conclusion, stilbenes were characteristic constituents of the tubers of B. striata with potential anti- neuroinflammatory effects.


Asunto(s)
Antiinflamatorios/química , Antiinflamatorios/farmacología , Microglía/efectos de los fármacos , Orchidaceae/química , Estilbenos/química , Estilbenos/farmacología , Animales , Antiinflamatorios/aislamiento & purificación , Línea Celular , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Lipopolisacáridos/inmunología , Ratones , Microglía/inmunología , Óxido Nítrico/inmunología , Tubérculos de la Planta/química , Estilbenos/aislamiento & purificación
18.
Bioorg Chem ; 97: 103690, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32126400

RESUMEN

Vernicia montana Lour. (tung tree) is an oil-producing plant with multiple uses, especially with its great potential in biodiesel production, which was a small Asian tree of the spurge family (Euphorbiaceae) with big economic values. However, studies on small molecular compositions of V. montana are limited. As a result, seven new lignans and one new coumacrin, and 21 known lignans, were isolated from the testas of V. montana. These isolates were confirmed in the light of spectroscopic tools (containing 1D and 2D NMR), ECD spectra methods. These isolates and crude extracts were evaluated their inhibitory activities using LPS-induced BV2 cells by assessing the NO production. Among them, compounds 3, 5, 6, 22 displayed significant effects, IC50 values about 11.4-20.9 µM. Together, the results demonstrated that lignans might be potential neuroinflammatory inhibitors.


Asunto(s)
Antiinflamatorios/química , Antiinflamatorios/farmacología , Euphorbiaceae/química , Lignanos/química , Lignanos/farmacología , Animales , Antiinflamatorios/aislamiento & purificación , Línea Celular , Lignanos/aislamiento & purificación , Lipopolisacáridos/inmunología , Ratones , Microglía/efectos de los fármacos , Microglía/inmunología , Modelos Moleculares , Óxido Nítrico/inmunología
19.
Bioorg Chem ; 101: 104038, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32629284

RESUMEN

Neuroinflammation is linked to neurodegenerative diseases, manifested by the microglial-released over-production of nitric oxide (NO). However, so far there is no effective strategy regarding curing or preventing neurodegenerative diseases. Triterpene saponins from Xanthoceras sorbifolium were proved to be capable of eliciting a protective effect in neurodegenerative diseases. Thus, a systematic chemical study on the 70% ethanol extract of X. sorbifolium was conducted, leading to the identification of 22 compounds, including four previously undescribed triterpenes saponins and 14 known ones, along with four alkaloids. Their structures were elucidated by physicochemical and spectral methods. The in vivo anti-AD effects of 1-18 were predicted with a field-based 3D-QSAR model and anti-neuroinflammatory activities were assayed in BV-2 cells by assessing LPS-induced NO production and examine levels of iNOS, TNF-α, IL-1ß, and IL-6 to support the predicted results. As a result, compounds 14, 16, 19, and 20 could have therapeutic potentials for neurodegenerative diseases due to their potent anti-neuroinflammatory activities.


Asunto(s)
Enfermedades Neurodegenerativas/tratamiento farmacológico , Sapindaceae/química , Humanos
20.
Bioorg Chem ; 104: 104338, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33142410

RESUMEN

Nine undescribed (1-4, 6-10) sesquiterpene coumarins, together with a new natural one (5) and ten known ones (11-20), were isolated from the low polarity fraction of the 95% ethanol extract of the resin of Ferula sinkiangensis. Their structures were elucidated based on the comprehensive analysis of HRESIMS, 1D and 2D NMR data. The absolute configurations were determined by comparison of experimental and calculated ECD spectra. All the identified SCs were evaluated for their anti-neuroinflammatory activities in LPS-induced BV-2 cells. Ferusingensine G (8) displayed a significant inhibitory effect on nitric oxide (NO) production with an IC50 value of 1.2 µM. The results suggested that natural SCs might be served as potential neuroinflammatory inhibitors.


Asunto(s)
Antiinflamatorios/farmacología , Cumarinas/farmacología , Ferula/química , Microglía/efectos de los fármacos , Resinas de Plantas/química , Sesquiterpenos/farmacología , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cumarinas/química , Cumarinas/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Microglía/metabolismo , Simulación del Acoplamiento Molecular , Estructura Molecular , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Relación Estructura-Actividad
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