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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 266: 120474, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34689088

RESUMO

A new fluorescent sensing microtiter plate (MTP) was developed for high sensitivity monitoring of anthracene in seawater samples. For this purpose, two ternary complexes of Tb(III) ions with dibenzoylmethane and neocuproine [Tb(DBM)2(MePhen)] or with dibenzoylmethane and bathocuproine [Tb(DBM)2(PhMePhen)] were synthesized. Elemental analysis, energy dispersive X-ray analysis, X-ray diffraction, infrared and ultraviolet-visible emission, and thermal analysis were conducted on the Tb(III) complexes. The limits of detection (DL) were 0.14 and 1.05 µmol L-1 for [Tb(DBM)2(MePhen)] and [Tb(DBM)2(PhMePhen)], respectively. [Tb(DBM)2(PhMePhen)] MTP is embedded in a membrane made of cellulose acetate. The first high-throughput anthracene sensor MTP, based on [Tb(DBM)2(PhMePhen)] sensor showed a linear range, from 0.2 to 20 µmol L-1. [Tb(DBM)2(PhMePhen)] MTP was validated for accurate and precise monitoring of anthracene using gas chromatography. The selectivity of the [Tb(DBM)2(PhMePhen)] MTP toward anthracene was examined. The data indicated that [Tb(DBM)2(PhMePhen)] MTP is suitable for rapid and direct detection of anthracene.


Assuntos
Antracenos , Térbio , Íons , Água do Mar , Difração de Raios X
2.
Sci Total Environ ; 802: 149793, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34454143

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are epidemiologically associated with cardiovascular diseases characterized by early key events involving in the disruption of endothelial barrier function. Whether PAHs can induce adverse cardiovascular outcome by directly destabilizing endothelial barrier function remains elusive. Herein, we investigated the effect of anthracene (ANT), 9-nitroanthracene (9-NANT), and 9,10-anthraquinone (9,10-AQ) on vascular endothelial barrier functions in human umbilical vein endothelial cells (HUVECs). The integrity of endothelial barrier in HUVECs was disturbed with a 1.15-1.42 fold increase in fluorescein leakage, and 21.8%-58.3% downregulated transendothelial electrical resistance. ANT, 9-NANT and 9,10-AQ promoted paracellular gap formation as revealed by transmission electron microscope. The disrupted cell junctions after 24 h exposure to ANT, 9-NANT and 9,10-AQ at 0.01 µM were indicated by the downregulated mRNA expression of vascular endothelial cadherin (VE-cadherin), zona occludens-1 (ZO-1) and occludin by 33.2%-71.4%, 19.1%-21.0%, and 31.9% respectively, and the downregulated protein expression of ZO-1 and occludin, and by the internalization of VE-cadherin. We demonstrated that ANT and its derivatives at environmentally relevant concentrations induced endothelial barrier dysfunction via the disruption of cell junctions, providing essential in vitro evidence on the association with their adverse cardiovascular outcomes.


Assuntos
Antracenos , Nitratos , Hidrocarbonetos Policíclicos Aromáticos , Antracenos/toxicidade , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana , Humanos , Óxidos de Nitrogênio
3.
J Chromatogr A ; 1657: 462575, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34601254

RESUMO

This work reports a selective and inert triptycene-based stationary phase (TPT) combining the triptycene framework with tocopheryl polyethylene glycol succinate (TPGS) units for capillary gas chromatography (GC). The TPT stationary phase was physically coated onto a capillary column by static coating method with the column efficiency of 4200 plates/m and moderate polarity. As demonstrated, the TPT column exhibited high inertness towards organic bases, including basic heterocycles, aliphatic and aromatic amines, showing distinct advantages over the TPGS and commercial columns. Also, the TPT column displayed high-resolution performance towards the isomers of methylpyridines, toluidines, xylidines and alkanes (C6-C8). Moreover, it showed excellent separation repeatability and reproducibility with RSD values in the range of 0.03%-0.07% for run-to-run, 0.12%-0.18% for day-to-day and 2.3%-3.6% for column-to- column (n = 4). Its applications to purity test of chemical products and to GC-MS analysis of the essential oil of Artemisia annua L. demonstrated its good potential for practical analyses. The present work has novelty in constructing highly selective and inert stationary phases and providing a feasible strategy for concurrently addressing the related problems in GC analyses. Its methodology and findings is of important value in terms of fundamental researches and practical applications.


Assuntos
Fenóis , Polietilenoglicóis , Antracenos , Cromatografia Gasosa , Fenóis/análise , Reprodutibilidade dos Testes , Succinatos
4.
Int J Pharm ; 609: 121195, 2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34673168

RESUMO

The potent photodynamic properties of Hypericin (Hyp) elicit a range of light-dose-dependent anti-tumor activities. However, its low water solubility hampers its broad application. Therefore, the administration of Hyp into biological systems requires drug carriers that would enable sufficient bioavailability. Stimuli-triggered nanocarriers, which are sensitive to endogenous or exogenous stimuli, have become an attractive replacement for conventional therapeutic regimens. Herein, we produced optimized Hyp thermosensitive liposomes (Hyp-TSL), self-assembled from DPPC, DSPC, DSPE-PEG2000. Hyp-TSL displayed a hydrodynamic diameter below 100 nm with an adequate encapsulation efficiency of 94.5 % and good colloidal stability. Hyp-TSL exhibited thermal sensitivity over a narrow range with a phase transition temperature of 41.1 °C, in which liposomal destruction was evident in AFM images after elevated temperature above the phase transition temperature. The uptake of TSL-Hyp into MDA-MB-231 cells was significantly increased with hyperthermic treatment of 42 °C when compared to the uptake at a average physiological temperature of 37 °C. Consequent enhancement of cellular reactive oxygen species was observed after hyperthermic treatment at 42 °C. The half-maximal inhibitory concentration of Hyp TSL was reduced by 3.8 fold after hyperthermic treatment at 42 °C in comparison to treatment at 37 °C. Hyp-TSL were considered safe for intravenous applications as compared by hemocompatibility studies, where coagulation time was <50 s and hemolytic potential was <10%. Conclusively, the enhancement in tumor drug availability correlated with improved therapeutic outcomes.


Assuntos
Hipertermia Induzida , Perileno , Antracenos , Lipossomos , Perileno/análogos & derivados , Solubilidade
5.
PLoS One ; 16(9): e0257808, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34582495

RESUMO

The Ultraviolet-visible (UV-Vis) spectra indicate that anthracenyl chalcones (ACs) have high maximum wavelengths and good transparency windows for optical applications and are suitable for optoelectronic applications owing to their HOMO-LUMO energy gaps (2.93 and 2.76 eV). Different donor substituents on the AC affect their dipole moments and nonlinear optical (NLO) responses. The positive, negative, and neutral electrostatic potential regions of the molecules were identified using molecular electrostatic potential (MEP). The stability of the molecule on account of hyperconjugative interactions and accompanying charge delocalization was analyzed using natural bond orbital (NBO) analysis. Open and closed aperture Z-scans were performed using a continuous-wave frequency-doubled diode-pumped solid-state (DPSS) laser to measure the nonlinear absorption and nonlinear refractive index coefficients, respectively. The valley-to-peak profile of AC indicated a negative nonlinear refractive index coefficient. The obtained single crystals possess reverse saturation absorption due to excited-state absorption. The structural and nonlinear optical properties of the molecules have been discussed, along with the role of anthracene substitution for enhancing the nonlinear optical properties. The calculated third-order susceptibility value was 1.10 x10-4 esu at an intensity of 4.1 kW/cm2, higher than the reported values for related chalcone derivatives. The NLO response for both ACs offers excellent potential in optical switching and limiting applications.


Assuntos
Antracenos/química , Chalconas/química , Compostos de Anéis Fundidos/química , Cristalografia por Raios X , Teoria da Densidade Funcional , Estrutura Molecular , Teoria Quântica
6.
Chem Asian J ; 16(20): 3091-3096, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34510777

RESUMO

Several sulfoxide- and sulfone-bridged ß-cyclodextrin (CD) dimers were synthesized for mediating the enantiodifferentiating [4+4] photocyclodimerization of 2-anthracenecarboxylic acid (AC). The complexation behavior of these chiral hosts with AC was investigated by UV-vis, circular dichroism, fluorescence, and NMR spectroscopies and certified the formation of 1 : 1 and 1 : 2 host-guest complexes. The product distribution and enantioselectivity of the photoreaction turned out to be a critical function of the chemical structure of bridged CDs. Comparing to the sulfur-bridged 2AX -3GX ß-CD dimer 7, the conversion of the photolyzes with sulfoxide-bridged was significantly improved, and the ee of cyclodimer 2 was remarkably increased from -82.8% with 7 to -96.7% with the sulfoxide-bridged 2AX -3GX ß-CD dimer 8. The relative yields and ee values of the slipped cyclodimers 5 and 6 were greatly enhanced in the presence of 6 M CsCl. The reaction selectivity is susceptible to the pH variation of the aqueous buffer solution, demonstrating that the supramolecular photochirogenesis is controlled by multidimensional factors, including the chemical structure of the chiral host, solvent, and pH conditions.


Assuntos
Antracenos/química , Ácidos Carboxílicos/química , beta-Ciclodextrinas/química , Dimerização , Concentração de Íons de Hidrogênio , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular , Processos Fotoquímicos , Solventes/química , Estereoisomerismo
7.
Mater Sci Eng C Mater Biol Appl ; 129: 112420, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34579929

RESUMO

Zein is an FDA-approved maize protein featured by its manipulative surface and the possibility of fabrication into nanomaterials. Although extensive research has been carried out in zein-based technology, limited work is available for the application of zein in the field of cancer photodynamic therapy (PDT). In this work, we report zein as a carrier for the natural photosensitizer hypericin in the PDT of hepatocellular carcinoma in vitro. Zein was modified through chemical PEGylation to form PEGylated zein micelles that were compared with two zein nanoparticle formulations physically stabilized by either the lecithin/pluronic mixture or sodium caseinate. FT-IR, 1HNMR and HP-SEC MALS approaches were employed to confirm the chemical PEGylation of zein. Our developed zein nanoparticles and micelles were further characterized by photon correlation spectroscopy (PCS) and atomic force microscopy (AFM). The obtained results showed relatively smaller sizes and higher encapsulation of hypericin in the micellar zein than the nanoparticle-based formulations. Phototoxicity on hepatocellular carcinoma (HepG2 cells) manifested a dose-dependent toxicity pattern of all designed zein formulations. However, superior cytotoxicity was prominent for the hypericin-based micelles, which was influenced by the higher cellular uptake profile. Consequently, the treated HepG2 cells manifested a higher level of intracellular generated ROS and disruption of mitochondrial membrane potential, which induced apoptotic cell death. Comparatively, the designed hypericin formulations indicated lower phototoxicity profile in murine fibroblast L929 cells reflecting their safety on normal cells. Our investigations suggested that the surface-modified zein could be employed to enhance the delivery of the hydrophobic hypericin in PDT and pave the way for future in vivo and clinical applications in cancer treatment.


Assuntos
Neoplasias Hepáticas , Perileno , Fotoquimioterapia , Zeína , Animais , Antracenos , Camundongos , Perileno/análogos & derivados , Perileno/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
8.
J Photochem Photobiol B ; 223: 112303, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34509718

RESUMO

Hypericin (Hy) is a hydrophobic photosensitizer used in photodynamic therapy for cancer therapeutic. In this study, Hy-loaded oil-in-water (O/W) nanoemulsions (NEs) were produced by the ultrasonication method combing different biocompatible oils and surfactants to enhance Hy aqueous solubility and bioavailability. Experimental parameters were optimized by the characterization of droplet size, zeta potential, and physicochemical properties. In vitro studies based on the release profile, cytotoxicity, cell morphology, and Hy intracellular accumulation were assayed. Hy at 100 mg L-1 was incorporated into the low viscosity (~0.005 Pa s) NEs with spherical droplets averaging 20-40 nm in size and polydispersity index <0.02. Hy release from the NE was significantly higher (4-fold) than its suspension (p < 0.001). The NEs demonstrated good physical stability during storage at 5 °C for at least six months. The Hy-loaded NEs exhibited an IC50 value 6-fold lower than Hy suspension during PDT against breast cancer cell lines (MCF-7). Cell microscopy imaging confirmed the increased cytotoxic effects of Hy-loaded NEs, showing damaged and apoptotic cells. Confocal laser scanning microscopy evidenced greater Hy delivery through NE into MCF-7 cells followed by improved intracellular ROS generation. Our results suggest that the Hy-loaded NEs can improve hypericin efficacy and assist Hy-PDT's preclinical development as a cancer treatment.


Assuntos
Antracenos/química , Emulsões/química , Nanoestruturas/química , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Radiossensibilizantes/química , Antracenos/metabolismo , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos/efeitos da radiação , Estabilidade de Medicamentos , Humanos , Luz , Células MCF-7 , Óleos/química , Perileno/química , Perileno/metabolismo , Perileno/farmacologia , Radiossensibilizantes/metabolismo , Radiossensibilizantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Sonicação , Temperatura , Água/química
9.
Nanoscale ; 13(35): 14713-14722, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34473183

RESUMO

Efficient drug delivery, multifunctional combined therapy and real-time diagnosis are the main hallmarks in the exploitation of precision nanomedicine. Herein, an anthracene-functionalized micelle containing a magnetic resonance imaging (MRI) contrast agent, upconversion nanoparticles (UCNPs) and the photosensitizer IR780 is designed to achieve sustained drug release and enhanced photothermal and photodynamic therapy. The polymer-coated hybrid micelle was achieved by crosslinking anthracene-dimer with UV light (λ > 300 nm), which is converted from near-infrared (NIR) irradiation upon UCNPs. Besides, the water-insoluble photosensitizer IR780 is introduced into the system to achieve efficient drug delivery and photothermal and photodynamic synergistic therapy. As a consequence of NIR-induced anthracene-dimer formation, the cross-linked nanocomposite shows sustained drug release, and the enhanced retention effect of IR780 could increase the photothermal conversion efficiency. Importantly, the incorporation of 2,2,6,6-tetramethyl-piperidineoxyl (TEMPO) as a nitroxide MRI contrast agent presents the potential for real-time diagnosis via nanotheranostics, and the fluorescence imaging of IR780 is applied to monitor drug distribution and metabolism. This strategy of sustained drug delivery by anthracene-dimer formation through the better penetration depth of NIR-II fluorescence provides an executable platform to achieve enhanced phototherapy in biomedical applications.


Assuntos
Nanocompostos , Nanopartículas , Fotoquimioterapia , Antracenos/farmacologia , Linhagem Celular Tumoral , Micelas , Fototerapia
10.
Biomacromolecules ; 22(10): 4199-4216, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34494830

RESUMO

Self-assembled nanostructures of amphiphilic gradient copoly(2-oxazoline)s have recently attracted attention as promising delivery systems for the effective delivery of hydrophobic anticancer drugs. In this study, we have investigated the effects of increasing hydrophobic side chain length on the self-assembly of gradient copolymers composed of 2-ethyl-2-oxazoline as the hydrophilic comonomer and various 2-(4-alkyloxyphenyl)-2-oxazolines as hydrophobic comonomers. We show that the size of the formed polymeric nanoparticles depends on the structure of the copolymers. Moreover, the stability and properties of the polymeric assembly can be affected by the loading of hypericin, a promising compound for photodiagnostics and photodynamic therapy (PDT). We have found the limitation that allows rapid or late release of hypericin from polymeric nanoparticles. The nanoparticles entering the cells by endocytosis decreased the hypericin-induced PDT, and the contribution of the passive process (diffusion) increased the probability of a stronger photoeffect. A study of fluorescence pharmacokinetics and biodistribution revealed differences in the release of hypericin from nanoparticles toward the quail chorioallantoic membrane, a preclinical model for in vivo studies, depending on the composition of polymeric nanoparticles. Photodamage induced by PDT in vivo well correlated with the in vitro results. All formulations studied succeeded in targeting hypericin at cancer cells. In conclusion, we demonstrated the promising potential of poly(2-oxazoline)-based gradient copolymers for effective drug delivery and sequential drug release needed for successful photodiagnostics and PDT in cancer therapy.


Assuntos
Nanopartículas , Fotoquimioterapia , Antracenos , Oxazóis , Perileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Polímeros , Distribuição Tecidual
11.
J Org Chem ; 86(19): 13491-13502, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34514788

RESUMO

In this study we found that 2,6-dimethanolpyridine displays good complementarity toward di(ethylene glycol) for the complexation of Na+ ions, allowing us to use this recognition system for the efficient synthesis of hetero[2]catenanes; indeed, it allowed us to attach multiple copies of [2]catenanes to branched systems presenting multiple isophthalaldehyde units. When we attempted to form a catenane from a preformed macrocycle featuring only a single di(ethylene glycol) unit, reacting it with a di(ethylene glycol) derivative presenting two amino termini, isophthalaldehyde, and templating Na+ ions [i.e., with the aim of using di(ethylene glycol)·Na+·di(ethylene glycol) recognition to template the formation of the interlocked imino macrocycle], the yields of the hetero[2]catenane and homo[2]catenane, comprising two imino macrocyclic units, were both poor (14% and 7%, respectively). In contrast, when one or two 2,6-dimethanolpyridine units were present in the preformed macrocycles, their reactions with the same diamine, dialdehyde, and Na+ ions provided the hetero[2]catenanes with high selectivity and efficiency (44% and 64% yields, respectively), with minimal formation of the competing homo[2]catenane. The high complementary of the 2,6-dimethanolpyridine·Na+·di(ethylene glycol) ligand pair allowed us to synthesize [2]catenane dimers and trimers directly from corresponding isophthalaldehyde-presenting cores, with yields, after subsequent reduction and methylation, of 42% and 31%, respectively.


Assuntos
Catenanos , Etilenoglicol , Antracenos , Íons , Espectroscopia de Ressonância Magnética
12.
J Phys Chem Lett ; 12(39): 9525-9530, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34559971

RESUMO

Triplet-triplet annihilation (TTA) upconversion has shown promising potentials in the augmentation of solar energy conversion. However, challenging issues exist in improving TTA upconversion efficiencies in solid-states, one of which is the back energy transfer from upconverted singlet annihilators to sensitizers, resulting in decreasing upconversion emission. Here we present a light-harvesting molecular wire consisting of dendrons with 9,10-diphenylanthracene derivatives (DPAEH) at the periphery and p-phenylene ethynylene oligomers (PPE) as the wire core. The peripheral DPAEH antenna funnels singlet excitonic energy to the wire on a 12 ps time scale. Incorporating the molecular wire into the TTA upconversion solid consisting of the DPAEH annihilator and the porphyrin sensitizer evidently improves the upconversion quantum yield from 1.5% to 2.7% upon 532 nm excitation by suppressing the back energy transfer from the singlet annihilator to the sensitizer. This finding offers a potential route to use a singlet energy light-harvesting architecture for enhancing TTA upconversion.


Assuntos
Energia Solar , Antracenos/química , Transferência de Energia , Porfirinas/química , Espectrometria de Fluorescência
13.
Viruses ; 13(9)2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34578406

RESUMO

The porcine epidemic diarrhea virus (PEDV) is an Alphacoronavirus (α-CoV) that causes high mortality in infected piglets, resulting in serious economic losses in the farming industry. Hypericin is a dianthrone compound that has been shown as an antiviral activity on several viruses. Here, we first evaluated the antiviral effect of hypericin in PEDV and found the viral replication and egression were significantly reduced with hypericin post-treatment. As hypericin has been shown in SARS-CoV-2 that it is bound to viral 3CLpro, we thus established a molecular docking between hypericin and PEDV 3CLpro using different software and found hypericin bound to 3CLpro through two pockets. These binding pockets were further verified by another docking between hypericin and PEDV 3CLpro pocket mutants, and the fluorescence resonance energy transfer (FRET) assay confirmed that hypericin inhibits the PEDV 3CLpro activity. Moreover, the alignments of α-CoV 3CLpro sequences or crystal structure revealed that the pockets mediating hypericin and PEDV 3CLpro binding were highly conserved, especially in transmissible gastroenteritis virus (TGEV). We then validated the anti-TGEV effect of hypericin through viral replication and egression. Overall, our results push forward that hypericin was for the first time shown to have an inhibitory effect on PEDV and TGEV by targeting 3CLpro, and it deserves further attention as not only a pan-anti-α-CoV compound but potentially also as a compound of other coronaviral infections.


Assuntos
Alphacoronavirus/efeitos dos fármacos , Alphacoronavirus/fisiologia , Antracenos/farmacologia , Antivirais/farmacologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Infecções por Coronavirus/virologia , Perileno/análogos & derivados , Replicação Viral/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Antivirais/química , Chlorocebus aethiops , Proteases 3C de Coronavírus/química , Ativação Enzimática/efeitos dos fármacos , Modelos Moleculares , Perileno/farmacologia , Vírus da Diarreia Epidêmica Suína/efeitos dos fármacos , Proteínas Recombinantes , Relação Estrutura-Atividade , Suínos , Doenças dos Suínos/virologia , Células Vero
14.
J Neurosci ; 41(42): 8673-8685, 2021 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-34380759

RESUMO

Neuronal proton-gated acid-sensing ion channels (ASICs) participate in the detection of tissue acidosis, a phenomenon often encountered in painful pathologic diseases. Such conditions often involve in parallel the activation of various signaling pathways such as mitogen activated protein kinases (MAPKs) that ultimately leads to phenotype modifications of sensory neurons. Here, we identify one member of the MAPKs, c-Jun N-terminal kinase (JNK), as a new post-translational positive regulator of ASICs in rodent sensory neurons. Recombinant H+-induced ASIC currents in HEK293 cells are potently inhibited within minutes by the JNK inhibitor SP600125 in a subunit-dependent manner, targeting both rodent and human ASIC1b and ASIC3 subunits (except mouse ASIC3). The regulation by JNK of recombinant ASIC1b- and ASIC3-containing channels (homomers and heteromers) is lost on mutation of a putative phosphorylation site within the intracellular N- and the C-terminal domain of the ASIC1b and ASIC3 subunit, respectively. Moreover, short-term JNK activation regulates the activity of native ASIC1b- and ASIC3-containing channels in rodent sensory neurons and is involved in the rapid potentiation of ASIC activity by the proinflammatory cytokine TNFα. Local JNK activation in vivo in mice induces a short-term potentiation of the acid-induced cutaneous pain in inflammatory conditions that is partially blocked by the ASIC1-specific inhibitor mambalgin-1. Collectively, our data identify pain-related channels as novel physiological JNK substrates in nociceptive neurons and propose JNK-dependent phosphorylation as a fast post-translational mechanism of regulation of sensory-neuron-expressed ASIC1b- and ASIC3-containing channels that may contribute to peripheral sensitization and pain hypersensitivity.SIGNIFICANCE STATEMENT ASICs are a class of excitatory cation channels critical for the detection of tissue acidosis, which is a hallmark of several painful diseases. Previous work in sensory neurons has shown that ASICs containing the ASIC3 or the ASIC1b subunit are important players in different pain models. We combine here functional and pharmacological in vitro and in vivo approaches to demonstrate that the MAP Kinase JNK is a potent post-translational positive regulator, probably via direct phosphorylation, of rodent and human ASIC1b- and ASIC3-containing channels. This JNK-dependent, fast post-translational mechanism of regulation of sensory-neuron-expressed ASICs may contribute to peripheral sensitization and pain hypersensitivity. These data also identify pain-related channels as direct downstream effectors of JNK in nociceptors.


Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Dor/metabolismo , Processamento de Proteína Pós-Traducional/fisiologia , Canais Iônicos Sensíveis a Ácido/genética , Sequência de Aminoácidos , Animais , Anisomicina/farmacologia , Antracenos/farmacologia , Antracenos/uso terapêutico , Células Cultivadas , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Células HEK293 , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dor/tratamento farmacológico , Dor/genética , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Ratos Wistar
15.
Macromol Rapid Commun ; 42(22): e2100485, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34463379

RESUMO

The synthesis of 9-methylanthracenyl glycidyl ether (AnthGE) as a crosslinkable monomer that can be applied in anionic ring opening polymerization is reported. Diblock terpolymers of the composition methoxy-poly(ethylene oxide)-block-poly(2-ethylhexyl glycidyl ether-co-9-methylanthracenyl glycidyl ether) (mPEO-b-P(EHGE-co-AnthGE) with 10 to 24 wt% of AnthGE are synthesized and characterized. Their micellization behavior, as well as their light-induced core-crosslinking via irradiation with UV light (λ = 365 nm) is studied. The results are compared with studies on the dimerization, and the dimer cleavage via irradiation with UV-C light (λ = 254 nm), of the same diblock terpolymer in organic solution, and the small-molecule model compound 9-methoxymethylanthracene. Differences in 1 H NMR spectra of the crosslinked or dimerized compounds and reaction kinetics of the dimerization reactions under different conditions suggest possible side reactions for the case of the core-crosslinking of micelles in aqueous solution. These side reactions limit the reversibility of the anthracene dimerization reaction in aqueous solutions, even if the anthracene molecule is encapsulated within the hydrophobic core of a polymeric micelle.


Assuntos
Micelas , Polímeros , Antracenos , Polietilenoglicóis , Polimerização
16.
Exp Cell Res ; 406(1): 112755, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34332981

RESUMO

Liver cancer is one of the most common and high recurrence malignancies. Besides radiotherapy and surgery, chemotherapy also plays an essential role in the treatment of liver cancer. Sorafenib and sorafenib-based combination therapies have been proven efficacy against tumors. However, previous clinical studies have indicated that some patients with liver cancer are resistant to sorafenib treatment and the existing strategies are not satisfactory in the clinic. Therefore, it is urgent to investigate strategies to improve the effectiveness of sorafenib for liver cancer and to explore effective drug combinations. In the present study, we found that dichloroacetate (DCA) could significantly enhance the anti-tumor effect of sorafenib on liver cancer cells, including reduced viability and dramatically promoted apoptosis in liver cancer cells. Moreover, compared to sorafenib alone, the combination of DCA and sorafenib markedly increased the degradation of anti-apoptotic protein Mcl-1 by enhancing its phosphorylation. Overexpression of Mcl-1 could significantly attenuate the synergetic effect of DCA and sorafenib on apoptosis induction in liver cancer cells. Furthermore, we found that the ROS-JNK pathway was obviously activated in the DCA combined sorafenib group. The levels of ROS and p-JNK were dramatically up-regulated in the two drug combination groups. Antioxidant NAC could alleviate the synergetic effects of DCA and sorafenib on ROS generation, JNK activation, Mcl-1 degradation, and cell apoptosis. Moreover, DCA and sorafenib's effects on Mcl-1 degradation and apoptosis could also be inhibited by JNK inhibitor 'SP'600125. Finally, the synergetic effects of DCA and sorafenib on tumor growth suppression, Mcl-1 degradation and induction of apoptosis were also validated in liver cancer xenograft in vivo. These findings indicate that DCA enhances the anti-tumor effect of sorafenib via the ROS-JNK-Mcl-1 pathway in liver cancer cells. This study may provide new insights to improve the chemotherapeutic effect of sorafenib, which may be beneficial for further clinical application of sorafenib in liver cancer treatment.


Assuntos
Ácido Dicloroacético/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Hepáticas/tratamento farmacológico , MAP Quinase Quinase 4/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Sorafenibe/farmacologia , Acetilcisteína/farmacologia , Animais , Antracenos/farmacologia , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , MAP Quinase Quinase 4/antagonistas & inibidores , MAP Quinase Quinase 4/metabolismo , Masculino , Camundongos Nus , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443298

RESUMO

Naphthodianthrones such as fagopyrin and hypericin found mainly in buckwheat (Fagopyrum spp.) and St. John's wort (SJW) (Hypericum perforatum L.) are natural photosensitizers inside the cell. The effect of photosensitizers was studied under dark conditions on growth, morphogenesis and induction of death in Saccharomyces cerevisiae. Fagopyrin and hypericin induced a biphasic and triphasic dose response in cellular growth, respectively, over a 10-fold concentration change. In fagopyrin-treated cells, disruptions in the normal cell cycle progression were evident by microscopy. DAPI staining revealed several cells that underwent premature mitosis without budding, a striking morphological abnormality. Flow Cytometric (FC) analysis using a concentration of 100 µM showed reduced cell viability by 41% in fagopyrin-treated cells and by 15% in hypericin-treated cells. FC revealed the development of a secondary population of G1 cells in photosensitizer-treated cultures characterized by small size and dense structures. Further, we show that fagopyrin and the closely related hypericin altered the shape and the associated fluorescence of biofilm-like structures. Colonies grown on solid medium containing photosensitizer had restricted growth, while cell-to-cell adherence within the colony was also affected. In conclusion, the photosensitizers under dark conditions affected culture growth, caused toxicity, and disrupted multicellular growth, albeit with different efficiencies.


Assuntos
Antracenos/farmacologia , Corantes/farmacologia , Perileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Plâncton/crescimento & desenvolvimento , Quinonas/farmacologia , Saccharomycetales/crescimento & desenvolvimento , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fluorescência , Morfogênese/efeitos dos fármacos , Perileno/farmacologia , Plâncton/efeitos dos fármacos , Saccharomycetales/citologia , Saccharomycetales/efeitos dos fármacos
18.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361714

RESUMO

α-glucosidase is a major enzyme that is involved in starch digestion and type 2 diabetes mellitus. In this study, the inhibition of hypericin by α-glucosidase and its mechanism were firstly investigated using enzyme kinetics analysis, real-time interaction analysis between hypericin and α-glucosidase by surface plasmon resonance (SPR), and molecular docking simulation. The results showed that hypericin was a high potential reversible and competitive α-glucosidase inhibitor, with a maximum half inhibitory concentration (IC50) of 4.66 ± 0.27 mg/L. The binding affinities of hypericin with α-glucosidase were assessed using an SPR detection system, which indicated that these were strong and fast, with balances dissociation constant (KD) values of 6.56 × 10-5 M and exhibited a slow dissociation reaction. Analysis by molecular docking further revealed that hydrophobic forces are generated by interactions between hypericin and amino acid residues Arg-315 and Tyr-316. In addition, hydrogen bonding occurred between hypericin and α-glucosidase amino acid residues Lys-156, Ser-157, Gly-160, Ser-240, His-280, Asp-242, and Asp-307. The structure and micro-environment of α-glucosidase enzymes were altered, which led to a decrease in α-glucosidase activity. This research identified that hypericin, an anthracene ketone compound, could be a novel α-glucosidase inhibitor and further applied to the development of potential anti-diabetic drugs.


Assuntos
Antracenos/química , Proteínas Fúngicas/antagonistas & inibidores , Inibidores de Glicosídeo Hidrolases/química , Hipoglicemiantes/química , Perileno/análogos & derivados , alfa-Glucosidases/química , Antracenos/metabolismo , Sítios de Ligação , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Inibidores de Glicosídeo Hidrolases/metabolismo , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Hipoglicemiantes/metabolismo , Cinética , Simulação de Acoplamento Molecular , Nitrofenilgalactosídeos/química , Nitrofenilgalactosídeos/metabolismo , Perileno/química , Perileno/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/enzimologia , Ressonância de Plasmônio de Superfície , alfa-Glucosidases/metabolismo
19.
Cell Physiol Biochem ; 55(S3): 157-170, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34318654

RESUMO

BACKGROUND/AIMS: The Amyloid Precursor Protein (APP) is involved in the regulation of multiple cellular functions via protein-protein interactions and has been most studied with respect to Alzheimer's disease (AD). Abnormal processing of the single transmembrane-spanning C99 fragment of APP contributes to the formation of amyloid plaques, which are causally related to AD. Pathological C99 accumulation is thought to associate with early cognitive defects in AD. Here, unexpectedly, sequence analysis revealed that C99 exhibits 24% sequence identity with the KCNE1 voltage-gated potassium (Kv) channel ß subunit, comparable to the identity between KCNE1 and KCNE2-5 (21-30%). This suggested the possibility of C99 regulating Kv channels. METHODS: We quantified the effects of C99 on Kv channel function, using electrophysiological analysis of subunits expressed in Xenopus laevis oocytes, biochemical and immunofluorescence techniques. RESULTS: C99 isoform-selectively inhibited (by 30-80%) activity of a range of Kv channels. Among the KCNQ (Kv7) family, C99 isoform-selectively inhibited, shifted the voltage dependence and/or slowed activation of KCNQ2, KCNQ3, KCNQ2/3 and KCNQ5, with no effects on KCNQ1, KCNQ1-KCNE1 or KCNQ4. C99/APP co-localized with KCNQ2 and KCNQ3 in adult rat sciatic nerve nodes of Ranvier. Both C99 and full-length APP co-immunoprecipitated with KCNQ2 in vitro, yet unlike C99, APP only weakly affected KCNQ2/3 activity. Finally, C99 altered the effects on KCNQ2/3 function of inhibitors tetraethylammounium and XE991, but not openers retigabine and ICA27243. CONCLUSION: Our findings raise the possibility of C99 accumulation early in AD altering cellular excitability by modulating Kv channel activity.


Assuntos
Precursor de Proteína beta-Amiloide/farmacologia , Canais de Potássio KCNQ/genética , Canal de Potássio KCNQ2/genética , Canal de Potássio KCNQ3/genética , Fragmentos de Peptídeos/farmacologia , Sequência de Aminoácidos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Antracenos/farmacologia , Expressão Gênica , Humanos , Canais de Potássio KCNQ/metabolismo , Canal de Potássio KCNQ2/metabolismo , Canal de Potássio KCNQ3/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Oócitos/citologia , Oócitos/efeitos dos fármacos , Oócitos/metabolismo , Técnicas de Patch-Clamp , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Nós Neurofibrosos/efeitos dos fármacos , Nós Neurofibrosos/metabolismo , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Tetraetilamônio/farmacologia , Xenopus laevis
20.
ACS Infect Dis ; 7(8): 2073-2080, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34291902

RESUMO

Due to the emergence of multidrug resistant bacteria, the development of new antibiotics is required. We introduce here asymmetrically modified positively charged bis(methylpyridinium) anthracenes as a novel tunable scaffold, in which the two positive charges can be placed at a defined distance and angle. Our structure-activity relationship reveals that coupling the methylpyridiniums with alkynyl linkers to the central anthracene unit yields antibacterial compounds against a wide range of bacteria, including Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. Also, different mycobacteria, such as Mycobacterium smegmatis and Mycobacterium tuberculosis, are efficiently targeted by these compounds. The antibacterial activity depends on the number of alkynyl linkers and consequently also on the distance of the positive charges in the rigid anthracene scaffold. Additionally, the formation of an anthracene endoperoxide further increases the antibacterial activity, likely due to the release of toxic singlet oxygen that converts the endoperoxide back to the antibacterial anthracene scaffold with half-lives of several hours.


Assuntos
Antibacterianos , Bactérias Gram-Negativas , Antracenos/farmacologia , Antibacterianos/farmacologia , Bactérias Gram-Positivas , Testes de Sensibilidade Microbiana , Staphylococcus epidermidis
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