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1.
PLoS Biol ; 22(1): e3002462, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38289969

RESUMO

Mutations in the gene encoding Cu-Zn superoxide dismutase 1 (SOD1) cause a subset of familial amyotrophic lateral sclerosis (fALS) cases. A shared effect of these mutations is that SOD1, which is normally a stable dimer, dissociates into toxic monomers that seed toxic aggregates. Considerable research effort has been devoted to developing compounds that stabilize the dimer of fALS SOD1 variants, but unfortunately, this has not yet resulted in a treatment. We hypothesized that cyclic thiosulfinate cross-linkers, which selectively target a rare, 2 cysteine-containing motif, can stabilize fALS-causing SOD1 variants in vivo. We created a library of chemically diverse cyclic thiosulfinates and determined structure-cross-linking-activity relationships. A pre-lead compound, "S-XL6," was selected based upon its cross-linking rate and drug-like properties. Co-crystallographic structure clearly establishes the binding of S-XL6 at Cys 111 bridging the monomers and stabilizing the SOD1 dimer. Biophysical studies reveal that the degree of stabilization afforded by S-XL6 (up to 24°C) is unprecedented for fALS, and to our knowledge, for any protein target of any kinetic stabilizer. Gene silencing and protein degrading therapeutic approaches require careful dose titration to balance the benefit of diminished fALS SOD1 expression with the toxic loss-of-enzymatic function. We show that S-XL6 does not share this liability because it rescues the activity of fALS SOD1 variants. No pharmacological agent has been proven to bind to SOD1 in vivo. Here, using a fALS mouse model, we demonstrate oral bioavailability; rapid engagement of SOD1G93A by S-XL6 that increases SOD1G93A's in vivo half-life; and that S-XL6 crosses the blood-brain barrier. S-XL6 demonstrated a degree of selectivity by avoiding off-target binding to plasma proteins. Taken together, our results indicate that cyclic thiosulfinate-mediated SOD1 stabilization should receive further attention as a potential therapeutic approach for fALS.


Assuntos
Esclerose Lateral Amiotrófica , Animais , Camundongos , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Cisteína/genética , Mutação , Superóxido Dismutase/genética , Superóxido Dismutase/química , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1/genética
2.
EMBO J ; 40(13): e106183, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34010456

RESUMO

Exposure to heat stress triggers a well-defined acute response marked by HSF1-dependent transcriptional upregulation of heat shock proteins. Cells allowed to recover acquire thermotolerance, but this adaptation is poorly understood. By quantitative proteomics, we discovered selective upregulation of HSP70-family chaperone HSPA1 and its co-factors, HSPH1 and DNAJB1, in MCF7 breast cancer cells acquiring thermotolerance. HSPA1 was found to have dual function during heat stress response: (i) During acute stress, it promotes the recruitment of the 26S proteasome to translating ribosomes, thus poising cells for rapid protein degradation and resumption of protein synthesis upon recovery; (ii) during thermotolerance, HSPA1 together with HSPH1 maintains ubiquitylated nascent/newly synthesized proteins in a soluble state required for their efficient proteasomal clearance. Consistently, deletion of HSPH1 impedes thermotolerance and esophageal tumor growth in mice, thus providing a potential explanation for the poor prognosis of digestive tract cancers with high HSPH1 and nominating HSPH1 as a cancer drug target. We propose dual roles of HSPA1 either alone or in complex with HSPH1 and DNAJB1 in promoting quality control of nascent/newly synthesized proteins and cellular thermotolerance.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Linhagem Celular Tumoral , Proteínas de Choque Térmico HSP110/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Resposta ao Choque Térmico/fisiologia , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Controle de Qualidade , Regulação para Cima/fisiologia
3.
Chemistry ; 30(34): e202400046, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38619364

RESUMO

Förster resonance energy transfer (FRET) has been widely applied in fluorescence imaging, sensing and so on, while developing useful strategy of boosting FRET efficiency becomes a key issue that limits the application. Except optimizing spectral properties, promoting orientation factor (κ2) has been well discussed but rarely utilized for boosting FRET. Herein, we constructed binary nano-assembling of two thermally activated delayed fluorescence (TADF) emitters (2CzPN and DMAC-DPS) with J-type aggregate of cyanine dye (C8S4) as doping films by taking advantage of their electrostatic interactions. Time-resolved spectroscopic measurements indicated that 2CzPN/Cy-J films exhibit an order of magnitude higher kFRET than DMAC-DPS/Cy-J films. Further quantitative analysing on kFRET and kDET indicated higher orientation factor (κ2) in 2CzPN/Cy-J films play a key role for achieving fast kFRET, which was subsequently confirmed by anisotropic measurements. Corresponding DFT/TDDFT calculation revealed strong "two-point" electrostatic anchoring in 2CzPN/Cy-J films that is responsible for highly orientated transitions. We provide a new strategy for boosting FRET in nano-assemblies, which might be inspired for designing FRET-based devices of sensing, imaging and information encryption.

4.
Langmuir ; 40(4): 2352-2361, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38240141

RESUMO

In this study, we present a novel modified Stöber method utilizing cetyltrimethylammonium bromide (CTAB) as a mediator for the preparation of monodispersed, micron-sized supermicroporous silica particles. Observed results show prepared silica particles ranging in size from 0.64 to 1.36 µm with an increase in CTAB concentration from 1.0 to 5.0 mM. The particles exhibited low polydispersity (<5%), a high Brunauer-Emmett-Teller surface area (570 to 1064 m2/g), and pore volumes ranging from 0.22 to 0.39 cm3/g. The pore size, determined using the Barrett-Joyner-Halenda method from the adsorption branches of the isotherms, was approximately 1.9 nm, specifically 1.83, 1.85, and 1.90 nm, as the CTAB concentration increased from 1.0 to 2.5 and 5.0 mM, respectively. The resulting particles displayed a narrow distribution of pore diameters. In addition, to obtain an in-depth understanding of the role of CTAB on the preparation of silica particles, a possible mechanism is also investigated using conductivity, dynamic light scattering (DLS), zeta potential, FT-IR spectra, and transmission electron microscopy. Our findings demonstrate that CTAB plays multiple roles in the hydrolysis/condensation of TEOS (tetraethyl orthosilicate) and subsequent nucleation and growth of silica particles. CTAB acts as a template for superporosity, a stabilizer for colloids, and an accelerator for nucleation and growth, leading to formation of monodispersed micrometer silica particles. Further characterization through FT-IR and 29Si solid NMR spectra revealed that the micron silica particles were obtained with inhomogeneity in the condensation degree, allowing for selective etching through hot incubation to form micron-sized hollow silica spheres.

5.
Langmuir ; 40(24): 12565-12572, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38836786

RESUMO

Silica particles modified with amino groups hold immense potential across diverse fields, owing to their distinctive properties. The widely adopted method of surface modification, utilizing (3-aminopropyl)triethoxysilane (APTES), facilitates the incorporation of amino-functional groups onto the silica surface, thereby creating sites for subsequent functionalization with other molecules. In this context, the ability to precisely tailor the surface properties of amino-functionalized silica particles is crucial for optimizing their performance in various applications. In this work, we systematically investigated the influence of the APTES concentration and water content on the density of amino groups grafted on the silica surface within an ethanol-water mixture. The rational control of hydrolysis and condensation of APTES enabled the precise regulation of the amino density on the silica surface, resulting in a notable shift in the isoelectric point from 2.9 to 9.2. Subsequently, we assembled amino-functionalized silica with different isoelectric points with gold nanoparticles to demonstrate their tunable ability as surface-enhanced Raman scattering (SERS) substrates. This controlled and tailored amino-functionalization process opens up new routes for fine-tuning the properties of silica particles, thereby expanding their utility across various applications in materials science, nanotechnology, and biomedicine.

6.
Luminescence ; 39(3): e4712, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38481369

RESUMO

In this study, a novel fluorescent chemosensor 1 based on chromone-3-carboxaldehyde Schiff base was synthesized and featured through nuclear magnetic resonance (NMR) and mass spectra. Spectroscopic investigation indicated that the fluorescent sensor showed high selectivity toward Zn2+ over other metal ions and that the detection limit of 1 could reach 10-7  M. These indicated that 1 acted as a highly selective and sensitive fluorescence chemosensor for Zn2+ .


Assuntos
Corantes Fluorescentes , Bases de Schiff , Espectrometria de Fluorescência/métodos , Corantes Fluorescentes/química , Bases de Schiff/química , Cromonas , Zinco
7.
Langmuir ; 39(19): 6748-6755, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37144972

RESUMO

Using bovine serum albumin (BSA) as both a reductant and ligand had been developed as one of the most used approaches for synthesis of fluorescent Au nanoclusters (NCs), in which first HAuCl4 and BSA were mixed together and then NaOH was added to the mixture after a certain time to obtain the Au NCs. In this work, the role of sodium hydroxide in the formation and emission properties of the Au NCs was investigated systematically. It was revealed, for the first time, that activity of the gold precursor and, thus, emission properties of the resulting Au NCs are dependent upon the addition time of sodium hydroxide. Meanwhile, the reducing ability of BSA is dependent upon the concentration of sodium hydroxide added to the reaction solution. By optimization of the addition time and concentration of sodium hydroxide used, Au NCs with improved emission properties were successfully synthesized under relatively low BSA concentrations, which showed improved performance toward the sensing of Cu2+ ions.


Assuntos
Nanopartículas Metálicas , Soroalbumina Bovina , Ouro , Hidróxido de Sódio , Animais , Bovinos
8.
Acta Pharmacol Sin ; 44(1): 19-31, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35840658

RESUMO

Inflammatory bowel disease (IBD) is a global health burden whose existing treatment is largely dependent on anti-inflammatory agents. Despite showing some therapeutic actions, their clinical efficacy and adverse events are unacceptable. Resolution as an active and orchestrated phase of inflammation involves improper inflammatory response with three key triggers, specialized pro-resolving mediators (SPMs), neutrophils and phagocyte efferocytosis. The formyl peptide receptor 2 (FPR2/ALX) is a human G protein-coupled receptor capable of binding SPMs and participates in the resolution process. This receptor has been implicated in several inflammatory diseases and its association with mouse model of IBD was established in some resolution-related studies. Here, we give an overview of three reported FPR2/ALX agonists highlighting their respective roles in pro-resolving strategies.


Assuntos
Doenças Inflamatórias Intestinais , Receptores de Formil Peptídeo , Animais , Camundongos , Humanos , Receptores de Formil Peptídeo/metabolismo , Inflamação/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios/metabolismo , Neutrófilos/metabolismo , Doenças Inflamatórias Intestinais/tratamento farmacológico
9.
Mikrochim Acta ; 190(4): 123, 2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36892601

RESUMO

A flexible electrochemiluminescence (ECL) hydrogel sensor exhibiting good self-healing was constructed. A transparent self-healing oxidized sodium alginate/hydrazide polyethylene glycol (OSA/PEG-DH) hydrogel was prepared by crosslinking dynamic covalent acylhydrazone bond. The introduction of 4-amino-DL-phenylalanine, a catalyst with good biocompatibility, allows rapid gelation and self-healing of hydrogel under mild conditions. Using the hydrogel as the sensing substrate, the ionic liquid (IL) 2-hydroxy-N,N,N-trimethylethanaminium chloride and the luminescent reagent N-(aminobutyl)-N-(ethylisoluminol) (ABEI) were simultaneously immobilized in the OSA/PEG-DH hydrogel to obtain the ABEI/IL/OSA/PEG-DH hydrogel. The ABEI/IL/OSA/PEG-DH hydrogel can be directly used as a semi-solid electrolyte for constructing a flexible ECL hydrogel sensor for the detection of H2O2, which acted as a coreactant of ABEI. The prepared flexible ECL sensor showed good self-healing performance, can restore ECL signal intensity within 20 min after physical damage, and showed high accuracy in the analysis of complex serum samples. This research shed new light on the development of flexible ECL sensor for bioanalytical applications.

10.
Molecules ; 28(9)2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37175303

RESUMO

The commercialization of lithium manganese oxide (LMO) is seriously hindered by several drawbacks, such as low initial Coulombic efficiency, the degradation of the voltage and capacity during cycling, and the poor rating performance. Developing a simple and scalable synthesis for engineering with surface coating layers is significant and challenging for the commercial prospects of LMO oxides. Herein, we have proposed an efficient engineering strategy with a Nb2O5 coating layer. We dissolved niobate (V) ammonium oxalate hydrate and stoichiometric rich LMO (RLM) in deionized water and stirred constantly. Then, the target product was calcined at high temperature. The discharge capacity of the Nb2O5 coating RLM is increased from 195 mAh·g-1 (the RLM without Nb2O5) to 215 mAh·g-1 at a coating volume ratio of 0.010. The average voltage decay was 4.38 mV/cycle, which was far lower than the 7.50 mV/cycle for the pure LMO. The electrochemical kinetics results indicated that the performance was superior with the buffer engineering by the Nb2O5 coating of RLM, which provided an excellent lithium-ion conduction channel, and improved diffusion kinetics, capacity fading, and voltage decay. This reveals the strong potential of the Nb2O5 coating in the field of cathode materials for lithium-ion batteries.

11.
Small ; 18(4): e2106462, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34862733

RESUMO

Multi-resonance thermally activated delayed fluorescence (MR-TADF) material, which possesses the ability to achieve narrowband emission in organic light-emitting diodes (OLEDs), is of significant importance for wide color gamut and high-resolution display applications. To date, MR-TADF material with narrow full width at half-maximum (FWHM) below 0.14 eV still remains a great challenge. Herein, through peripheral protection of MR framework by phenyl derivatives, four efficient narrowband MR-TADF emitters are successfully designed and synthesized. The introduction of peripheral phenyl-based moieties via a single bond significantly suppresses the high-frequency stretching vibrations and reduces the reorganization energies, accordingly deriving the resulting molecules with small FWMH values around 20 nm/0.11 eV and fast radiative decay rates exceeding 108 s-1 . The corresponding green OLED based on TPh-BN realizes excellent performance with the maximum external quantum efficiency (EQE) up to 28.9% without utilizing any sensitizing host and a relatively narrow FWHM of 0.14 eV (28 nm), which is smaller than the reported green MR-TADF molecules in current literatures. Especially, the devices show significantly reduced efficiency roll-off and relatively long operational lifetimes among the sensitizer-free MR-TADF devices. These results clearly indicate the promise of this design strategy for highly efficient OLEDs with ultra-high color purity.

12.
Chemistry ; 28(26): e202104247, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35191569

RESUMO

Nanomaterials with oxidase- and peroxidase-like activities have potential in antibacterial therapy. The optimal activity of most nanozymes occurred in acidic pH (3.0-5.0), while the pH in biological systems is mostly near neutral. Herein, a general system using 9-fluorenylmethoxycarbonyl-modified diphenylalanine (Fmoc-FF) hydrogel for enhancing oxidase- and peroxidase-like activities of Pt NPs and other typical enzyme-like nanomaterials at neutral or even alkaline pH is proposed. In this system, Fmoc-FF hydrogel provides an acidic microenvironment for Pt NPs due to hydrogen protons (H+ ) produced by the dissociation of F at neutral pH. As a result, Pt NPs exhibits 6-fold enhanced oxidase-like and 26-fold peroxidase-like activity after being encapsulated into Fmoc-FF hydrogel at pH 7.0. Based on outstanding enzymatic activities and the antibacterial activity of Fmoc-FF hydrogel itself, Pt-Fmoc-FF hydrogel realizes excellent antibacterial effect. This design provides a universal strategy to break pH limitation of nanozymes and promotes the biological applications of nanozymes.


Assuntos
Hidrogéis , Peroxidase , Antibacterianos/farmacologia , Corantes , Concentração de Íons de Hidrogênio , Oxirredutases , Fenilalanina
13.
Inorg Chem ; 61(50): 20552-20560, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36475651

RESUMO

Metal halide hybrids with thermally induced fluorescence transition have the potential to be utilized as the next generation of smart materials in optoelectronic devices. However, the fabrication of thermochromic materials with simultaneously reversible and lower transition temperatures is still a challenge. Herein, we present a novel one-dimensional (1D) organic-inorganic lead chloride hybrid (TPA)PbCl3-Green (TPA = tetrapropylammonium) single crystal that exhibits green emission and up to 30% photoluminescence quantum yield (PLQY). It is worth noting that the (TPA)PbCl3-Green crystal changes emission from green to blue light when heated at 323 K. The emission spectra indicate that the blue light is attributed to the combination of two emission peaks located at 438 and 520 nm, respectively. Furthermore, the green luminescence is restored after natural cooling to room temperature. The dynamic transition process is demonstrated via steady-state photoluminescence, single-crystal X-ray diffraction (SCXRD), and powder X-ray diffraction (XRD). (TPA)PbCl3-Green crystals and (TPA)PbCl3-Green@PVP complexes have also been explored as fluorescent security inks for dynamic anticounterfeiting and message encryption as well as optical logic gate applications due to the excellent cycling stability and low transition temperature. This material offers a completely new option for thermochromic materials used for security information.

14.
BMC Neurol ; 22(1): 384, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224533

RESUMO

OBJECTIVES: Neurovascular compression (NVC) produces morphological changes on the trigeminal nerve root is considered the cause of trigeminal neuralgia (TN), but there were some patients with TN found no NVC, and also NVC was found in asymptomatic individuals. Many studies found tight relationships of TN and morphological structures of trigeminal nerve. We designed this study to explore the correlation between multiplanar reconstruction (MPR) trigeminal nerve angulation (TNA) and TN. METHODS: Patients with classical symptoms of TN were recruited as observation group (OG) in this study, 50 healthy controls were enrolled as control group (CG), the OG was further subtyped into young patients (YP), middle-aged patients (MP) and old patients (OP) based to the onset age of symptoms, and also divided into patients with or without trigger maneuvers (TM) based on the presence of TM or not. All the participants underwent magnetic resonance (MR) examinations in same device, bilateral TNA measurements were carried out in OG and CG, then TNA was compared between different groups or subgroups. All images were interpreted by two radiologists who were blinded to the study, diagnosis of TN was made by two senior neurosurgery professors. RESULT: Ultimately, 95 patients with primary TN were recruited in OG, aged from 25 to 84 (61.15 ± 12.70) years with a course of 0.5 to 30 (5.03 ± 5.41) years, their onset age ranged from 24 to 82 (56.13 ± 11.98) years. There were 34 males and 61 females in OG, and 58 cases involved right side. The CG aged from 22 to 85 (61.86 ± 13.03) years. No statistical difference was found between the age of OG and CG(p = 0.76), and also the bilateral TNA of CG (154.92 ± 16.90° vs 155.55 ± 17.03°, p > 0.05), while TNA of OG was significantly smaller than CG (150.78 ± 11.29° vs 155.24 ± 16.88°, p = 0.019). In OG, TNA on the affected side was significantly smaller than the unaffected side (149.29 ± 12.44° vs 152.27 ± 9.85°, p = 0.014). TNA showed a positive correlation with onset age of patients with TN, as TNA on the affected side of YP was significantly smaller than MP and OP (139.00 ± 11.64° vs 148.86 ± 11.54°, 139.00 ± 11.64° vs 152.18 ± 12.61°, p = 0.004 and 0.026). Furthermore, patients with TM showed smaller TNA than those without TM (147.05 ± 11.30° vs 164.75 ± 8.39°, p < 0.001). CONCLUSIONS: This study suggested that TNA might play a role in TN, small TNA could be a risk factor of TN. Furthermore, patients with small TNA are more likely to combine with TM, but more studies are needed to explore the exact role of TNA in TN.


Assuntos
Neuralgia do Trigêmeo , Adulto , Idoso , Idoso de 80 Anos ou mais , Correlação de Dados , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/efeitos adversos , Nervo Trigêmeo/diagnóstico por imagem , Nervo Trigêmeo/patologia , Neuralgia do Trigêmeo/diagnóstico , Adulto Jovem
15.
Org Biomol Chem ; 20(24): 4884-4887, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35670433

RESUMO

We have developed a new strategy of tumor-specific glucose transporter (GLUT)-mediated selective drug delivery using amphiphilic fluorescent monoglycocalix[4]arene in docetaxel (DTX) encapsulated nanoparticles (NPs) that leads to significant improvement in cytotoxic activity against a panel of human cancer cells. The fluorescent tracer conjugation in the calixarene enables the self-probed tumor targeting analysis and makes the system potentially suitable for tumor diagnostic imaging.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Docetaxel , Portadores de Fármacos , Sistemas de Liberação de Medicamentos/métodos , Transportador de Glucose Tipo 1 , Humanos , Neoplasias/tratamento farmacológico
16.
Angew Chem Int Ed Engl ; 61(14): e202116927, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35104385

RESUMO

Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show great potentials for high color purity organic light-emitting diodes (OLEDs). However, the simultaneous realization of high photoluminescence quantum yield (PLQY) and high reverse intersystem crossing rate (kRISC ) is still a formidable challenge. Herein, a novel asymmetric MR-TADF emitter (2Cz-PTZ-BN) is designed that fully inherits the high PLQY and large kRISC values of the properly selected parent molecules. The resonating extended π-skeleton with peripheral protection can achieve a high PLQY of 96 % and a fast kRISC of above 1.0×105  s-1 , and boost the performance of corresponding pure green devices with an outstanding external quantum efficiency (EQE) of up to 32.8 % without utilizing any sensitizing hosts. Remarkably, the device sufficiently maintains a high EQE exceeding 23 % at a high luminance of 1000 cd m-2 , representing the highest value for reported green MR-TADF materials at the same luminescence.

17.
Bioorg Med Chem ; 41: 116188, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34000508

RESUMO

Our continuing search for marine bioactive secondary metabolites led to the screening of crude extracts of sea cucumbers by the model of Pyricularia oryzae. A new sulfated triterpene glycoside, coloquadranoside A (1), together with four known triterpene glycosides, philinopside A, B, E and pentactaside B (2-5) were isolated from the sea cucumber Colochirus quadrangularis, and their structures were elucidated using extensive spectroscope analysis (ESI-MS, 1D and 2D NMR) and chemical methods. Coloquadranoside A possesses a 16-acetyloxy group in the holostane-type triterpene aglycone with a 7(8)-double bond, a double bond (25,26) at its side chain, and two ß-d-xylose in the carbohydrate chain. Coloquadranoside A exhibits in vitro some antifungus, considerable cytotoxicity (IC50 of 0.46-2.03 µM) against eight human tumor cell lines, in vivo antitumor, and immunomodulatory activity.


Assuntos
Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Glicosídeos/química , Imunomodulação/efeitos dos fármacos , Pepinos-do-Mar/química , Triterpenos/química , Animais , Antifúngicos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais , Saponinas/química
18.
Int J Mol Sci ; 22(7)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33805371

RESUMO

As an evolutionarily conserved pathway, mitogen-activated protein kinase (MAPK) cascades function as the key signal transducers that convey information by protein phosphorylation. Here we identified PlMAPK2 as one of 14 predicted MAPKs encoding genes in the plant pathogenic oomycete Peronophythora litchii. PlMAPK2 is conserved in P.litchii and Phytophthora species. We found that PlMAPK2 was up-regulated in sporangium, zoospore, cyst, cyst germination and early stage of infection. We generated PlMAPK2 knockout mutants using the CRISPR/Cas9 method. Compared with wild-type strain, the PlMAPK2 mutants showed no significant difference in vegetative growth, oospore production and sensitivity to various abiotic stresses. However, the sporangium release was severely impaired. We further found that the cleavage of the cytoplasm into uninucleate zoospores was disrupted in the PlMAPK2 mutants, and this developmental phenotype was accompanied by reduction in the transcription levels of PlMAD1 and PlMYB1 genes. Meanwhile, the PlMAPK2 mutants exhibited lower laccase activity and reduced virulence to lychee leaves. Overall, this study identified a MAPK that is critical for zoosporogenesis by regulating the sporangial cleavage and pathogenicity of P.litchii, likely by regulating laccase activity.


Assuntos
Litchi/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oomicetos/patogenicidade , Doenças das Plantas , Litchi/microbiologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/metabolismo , Virulência
19.
Angew Chem Int Ed Engl ; 60(24): 13548-13553, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33792143

RESUMO

Organic-inorganic metal-halide materials (OIMMs) with zero-dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well-defined optical performance at the micro-/nanometer scale are limited. We prepared one-dimensional (1D) (DTA)2 SbCl5 ⋅DTAC (DTAC=dodecyl trimethyl ammonium chloride) single-crystal microrods and 2D microplates with a 0D structure in which individual (SbCl5 )2- quadrangular units are completely isolated and surrounded by the organic cation DTA+ . The organic molecular unit with a long alkyl chain (C12 ) and three methyl groups enables microrod and -plate formation. The single-crystal microrods/-plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from self-trapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB µm-1 ) during propagation, and linear polarized photoemission with a polarization contrast (0.57).

20.
Small ; 16(44): e2004272, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33025738

RESUMO

Multi-metallic halides of group IA and IB metals are emerged as a new class of color tunable emitters. While chalcogenides and perovskites are extensively studied, these families of materials are little explored. In comparison, herein, lead and cadmium free bimetallic Cs-Ag-X (X = Cl, Br, I) halides are reported where the larger ion Ag+ helped in incorporating all the halide ions which in turn tune their emission color in spanning from 397 nm (violet) to 820 nm (near infrared) as a function of their composition. The synthesis method adopted here is the solvent free ball milling of respective halides of Cs and Ag and took the record shortest time and in bulk scale. From decay lifetimes, emissions from these bimetallic halides are found as a result of fast recombination of self-trapped excitons, which exhibited not only reasonably high quantum yield in the range of 17-68% but also excellent stability to air and moisture under ambient conditions. These also show wide Stokes shift with relatively longer decay lifetimes ranging above the exciton and below the surface trap or dopant induced emissions of inorganic semiconductors, indicating a new class of materials having unique identity of their optical behaviors.

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