RESUMO
The bacterial pathogen Legionella pneumophila creates an intracellular niche permissive for its replication by extensively modulating host-cell functions using hundreds of effector proteins delivered by its Dot/Icm secretion system1. Among these, members of the SidE family (SidEs) regulate several cellular processes through a unique phosphoribosyl ubiquitination mechanism that bypasses the canonical ubiquitination machinery2-4. The activity of SidEs is regulated by another Dot/Icm effector known as SidJ5; however, the mechanism of this regulation is not completely understood6,7. Here we demonstrate that SidJ inhibits the activity of SidEs by inducing the covalent attachment of glutamate moieties to SdeA-a member of the SidE family-at E860, one of the catalytic residues that is required for the mono-ADP-ribosyltransferase activity involved in ubiquitin activation2. This inhibition by SidJ is spatially restricted in host cells because its activity requires the eukaryote-specific protein calmodulin (CaM). We solved a structure of SidJ-CaM in complex with AMP and found that the ATP used in this reaction is cleaved at the α-phosphate position by SidJ, which-in the absence of glutamate or modifiable SdeA-undergoes self-AMPylation. Our results reveal a mechanism of regulation in bacterial pathogenicity in which a glutamylation reaction that inhibits the activity of virulence factors is activated by host-factor-dependent acyl-adenylation.
Assuntos
Calmodulina/metabolismo , Ácido Glutâmico/metabolismo , Legionella pneumophila/enzimologia , Legionella pneumophila/metabolismo , Ubiquitinação , ADP-Ribosilação , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Catálise , Domínio Catalítico , Coenzimas/metabolismo , Células HEK293 , Humanos , Legionella pneumophila/citologia , Modelos Moleculares , Ubiquitina/química , Ubiquitina/metabolismoRESUMO
We report a joint photoelectron spectroscopic and relativistic quantum chemistry study on gaseous NUO2-. The electron affinity (EA) of the neutral NUO2 molecule is reported for the first time with a value of 2.602(28) eV. The U-O and U-N stretching vibrational modes for the ground state and the first excited state are observed for NUO2. The geometric and electronic structures of both the anions and the corresponding neutrals are investigated by relativistic quantum chemistry calculations to interpret the photoelectron spectra and to provide insights into the nature of the chemical bonding. Both the ground state of the anion and neutral are calculated to be planar structures with C2v symmetry. Unlike the "T"-shape structure of UO3 which has a quasi-linear O-U-O angle, both the ground-state geometries of the anion and neutral have O-U-O bond angles of around 90°. The significant contraction of the O-U-O bond angle indicates the strong interaction between the U and N atoms compared with the "additional" oxygen in UO3. The chemical bonding calculation indicates that multiple bonding of U(VI) can occur in NUO2- and NUO2, and the UVI-N bond is significantly more covalent than the U-O bond. The current experimental and theoretical results reveal the difference between the U-N and U-O bond in the unified molecular system, and expand our understanding of the bonding capacities of actinide elements with the nitrogen atom.
RESUMO
Due to the abundant and promising biological activities of aromatic hydrazones, it is of great significance to study the biological activities of their metal complexes for the research and development of metal-based drugs. In this review, we focus on the metal complexes of polycyclic aromatic hydrazones, which still do not receive much attention, and summarize the studies related to their biological activities. Although the large number of metal complexes in phenylhydrazone prevent them all from being summarized, the significant value of polycyclic aromatic hydrocarbons themselves (such as naphthalene and anthracene) as pharmacophores are also considered. Therefore, the bioactivities of the metal complexes of naphthylhydrazone and anthrahydrazone are focused on, and the recent research progress on the metal complexes of anthrahydrazone by the authors is also included. In terms of biological activities, these complexes mainly show antibacterial and anticancer activities, along with less bioactivities. The present review demonstrates that the structural design and bioactivities of these complexes are fundamental, which also indicates a certain structure-activity relationship (SAR) in some substructural areas. However, a systematic and comprehensive conclusion of the SAR is still not available, which suggests that more attention should be paid to the bioactivities of the metal complexes of polycyclic aromatic hydrazones since their potential in structural design and biological activity remains to be explored. We hope that this review will attract more researchers to devote their interest and energy into this promising area.
Assuntos
Complexos de Coordenação , Hidrocarbonetos Policíclicos Aromáticos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Hidrazonas/farmacologia , Hidrazonas/química , Hidrocarbonetos Policíclicos Aromáticos/química , Metais/química , Antibacterianos/farmacologia , Antibacterianos/químicaRESUMO
As an immune checkpoint, programmed cell death 1 (PD-1) and its ligand (PD-L1) pathway plays a crucial role in CD8+ cytotoxic T lymphocytes (CTL) activation and provides antitumor responses. The N-glycans of PD-1 and PD-L1 are highly core fucosylated, which are solely catalyzed by the core fucosyltransferase (Fut8). However, the precise biological mechanisms underlying effects of core fucosylation of PD-1 and PD-L1 on CTL activation have not been fully understood. In this study, we found that core fucosylation was significantly upregulated in lung adenocarcinoma. Compared to those of Fut8+/+ OT-I mice, the lung adenocarcinoma formation induced by urethane was markedly reduced in Fut8-/- OT-I mice. De-core fucosylation of PD-1 compromised its expression on Fut8-/- CTL, resulted in enhanced Fut8-/- CTL activation and cytotoxicity, leading to more efficient tumor eradication. Indeed, loss of core fucosylation significantly enhanced the PD-1 ubiquitination and in turn led to the degradation of PD-1 in the proteasome. Our current work indicates that inhibition of core fucosylation is a unique strategy to reduce PD-1 expression for the antilung adenocarcinoma immune therapy in the future.
Assuntos
Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/terapia , Antineoplásicos/imunologia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/terapia , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T Citotóxicos/imunologia , Células A549 , Animais , Linhagem Celular , Linhagem Celular Tumoral , Fucosiltransferases/imunologia , Glicosilação , Células HEK293 , Humanos , Ativação Linfocitária/imunologia , Camundongos , Transdução de Sinais/imunologia , Regulação para Cima/imunologiaRESUMO
BACKGROUND: Prosthesis-related complications, after knee reconstruction with endoprosthesis during operation for tumors around the knee, remain an unresolved problem which necessitate a revision or even an amputational surgery. The purpose of the current study was to identify significant risk factors associated with implant failure, and establish a novel model to predict survival of the prosthesis in patients operated with endoprostheses for tumor around knee. METHODS: We retrospectively reviewed the clinical database of our institution for patients who underwent knee reconstruction due to tumors. A total of 203 patients were included, including 123 males (60.6%) and 80 (39.4%) females, ranging in age from 14 to 77 years (mean: 34.3 ± 17.3 years). The cohort was randomly divided into training (n = 156) and validation (n = 47) samples. Univariable COX analysis was used for initially identifying potential independent predictors of prosthesis survival with the training group (p < 0.150). Multivariate COX proportional hazard model was selected to identify final significant prognostic factors. Using these significant predictors, a graphic nomogram, and an online dynamic nomogram were generated for predicting the prosthetic survival. C-index and calibration curve were used for evaluate the discrimination ability and accuracy of the novel model, both in the training and validation groups. RESULTS: The 1-, 5-, and 10-year prosthetic survival rates were 94.0, 90.8, and 83.0% in training sample, and 96.7, 85.8, and 76.9% in validation sample, respectively. Anatomic sites, length of resection and length of prosthetic stem were independently associated with the prosthetic failure according to multivariate COX regression model (p<0.05). Using these three significant predictors, a graphical nomogram and an online dynamic nomogram model were generated. The C-indexes in training and validation groups were 0.717 and 0.726 respectively, demonstrating favourable discrimination ability of the novel model. And the calibration curve at each time point showed favorable consistency between the predicted and actual survival rates in training and validation samples. CONCLUSIONS: The length of resection, anatomical location of tumor, and length of prosthetic stem were significantly associated with prosthetic survival in patients operated for tumor around knee. A user-friendly novel online model model, with favorable discrimination ability and accuracy, was generated to help surgeons predict the survival of the prosthesis.
Assuntos
Prótese do Joelho/estatística & dados numéricos , Neoplasias/cirurgia , Nomogramas , Procedimentos de Cirurgia Plástica/métodos , Próteses e Implantes/estatística & dados numéricos , Falha de Prótese/tendências , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Adulto JovemRESUMO
Tetrazolium salts (TZs) are pervasively utilized as precursors in the dye industry, colorimetric probes in enzyme assays and for exploring nanomaterial toxicity, but its own toxicity is not investigated enough so far. Using femtosecond transient absorption spectroscopy, nanosecond pulse radiolysis (ns-PRL), western blotting and UV-vis absorption spectroscopy, here we characterized a neutral tetrazolinyl radical (with the same maximum absorption at 420 nm and different lifetimes of 5.0 and 9.0 µs for two selected TZs), the key intermediate of TZs reduction, and noticed TZs-formazan production under UV light irradiation accompanied by 41% increase in the cross-linking of lysozyme (Lyso, model protein) compared to TZs-free sample, which uncovered the photoenhanced oxidation of TZs towards Lyso. The ns-PRL in a reductive atmosphere simulated the electron/proton donors of amino acid residues in Lyso upon photoexcitation and revealed the reduction mechanism of TZs, as that first followed one-electron-transfer and then probably proton-coupled electron transfer. This is the first time to report on the photoenhanced oxidation mechanism of TZs, which would provide new insights into the applications of TZs in cell biology, "click" chemistry and nanotoxicology.
Assuntos
Aminoácidos/química , Muramidase/química , Sais de Tetrazólio/química , Aminoácidos/efeitos da radiação , Animais , Galinhas , Radicais Livres/química , Muramidase/efeitos da radiação , Oxirredução , Sais de Tetrazólio/efeitos da radiação , Raios UltravioletaRESUMO
The smut fungus Ustilago esculenta infects Zizania latifolia and induces stem expansion to form a unique vegetable named Jiaobai. Although previous studies have demonstrated that hormonal control is essential for triggering stem swelling, the role of hormones synthesized by Z. latifolia and U. esculenta and the underlying molecular mechanism are not yet clear. To study the mechanism that triggers swollen stem formation, we analyzed the gene expression pattern of both interacting organisms during the initial trigger of culm gall formation, at which time the infective hyphae also propagated extensively and penetrated host stem cells. Transcriptional analysis indicated that abundant genes involving fungal pathogenicity and plant resistance were reprogrammed to maintain the subtle balance between the parasite and host. In addition, the expression of genes involved in auxin biosynthesis of U. esculenta obviously decreased during stem swelling, while a large number of genes related to the synthesis, metabolism and signal transduction of hormones of the host plant were stimulated and showed specific expression patterns, particularly, the expression of ZlYUCCA9 (a flavin monooxygenase, the key enzyme in indole-3-acetic acid (IAA) biosynthesis pathway) increased significantly. Simultaneously, the content of IAA increased significantly, while the contents of cytokinin and gibberellin showed the opposite trend. We speculated that auxin produced by the host plant, rather than the fungus, triggers stem swelling. Furthermore, from the differently expressed genes, two candidate Cys2-His2 (C2H2) zinc finger proteins, GME3058_g and GME5963_g, were identified from U. esculenta, which may conduct fungus growth and infection at the initial stage of stem-gall formation.
Assuntos
Basidiomycota/genética , Resistência à Doença/genética , Perfilação da Expressão Gênica/métodos , Doenças das Plantas/genética , Tumores de Planta/genética , Poaceae/genética , Sequência de Aminoácidos , Basidiomycota/metabolismo , Basidiomycota/patogenicidade , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/genética , Hifas/genética , Hifas/metabolismo , Hifas/patogenicidade , Ácidos Indolacéticos/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Filogenia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Plantas/biossíntese , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Tumores de Planta/microbiologia , Poaceae/metabolismo , Poaceae/microbiologia , Homologia de Sequência de Aminoácidos , Virulência/genéticaRESUMO
Background. Negative-pressure wound therapy is applied increasingly to manage closed wounds. However, no consensus has been reached with regard to surgical site infection and wound complication. Aim. To evaluate the effect of negative pressure therapy on closed wounds after orthopedic surgeries. Methods. PubMed, EMBASE, Cochrane Library, and MEDLINE databases were searched from 1966 to January 2019; the references in the identified studies were also searched. Results. Ten studies on arthroplasty and 3 studies on fractures were included. Significantly few infections appeared in the negative pressure group (odds ratio [OR] = 0.28, 95% confidence interval [CI] = 0.18-0.46, P < .001; I2 = 0%, P = .80). There was no significant difference for other complications (OR = 0.54, 95% CI = 0.21-1.39, P = .20; I2 = 81%, P < .001). Few patients needed reoperation in the negative pressure group (OR = 0.28, 95% CI = 0.14-0.53, P < .001; I2 = 0%, P = .82). Conclusion. Negative pressure therapy can decrease surgical site infection and reoperation of closed incisions.
Assuntos
Tratamento de Ferimentos com Pressão Negativa , Procedimentos Ortopédicos/efeitos adversos , Infecção da Ferida Cirúrgica , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controleRESUMO
Knowledge of the local Th structure is a prerequisite for a better understanding of the physicochemical properties of the thorium-based mixed oxides (Th-MOX) involved in the Th-based nuclear fuel cycle. The crystalline electric field (CEF) splitting of the 6d shell in Th1- xU xO2 ( x = 0.25, 0.5, 0.75) solid solution was probed by the Th L3 edge high-energy-resolution fluorescence-detected (HERFD) X-ray absorption near-edge spectroscopy (XANES) collected at the Lß5 emission line, which cannot be obtained by conventional X-ray absorption methods. The detected CEF split between the 6d eg and t2g orbitals in ThO2 consisting of ordered Th-O8 cubes with cubic symmetry is â¼3.5 eV for the Th4+ ion. Because the split peaks of the white line corresponding to the crystal-field splitting of the unoccupied 6d states were resolved in the HERFD-XANES spectra, the analysis of these split peaks combined with first-principles calculations revealed that an increase of the U content involves the distortion of the Th-O8 cubes in the Th1- xU xO2 mixed oxides. The lower symmetry of the Th-O8 cube induced by the incorporated U tends to reduce the local crystal-field around Th4+ as well as the hybridization of Th 6t2g-O 2p which is mainly responsible for the covalent property of the Th-O bond. The phenomenon is noticeable in Th0.25U0.75O2, whose CEF splitting is decreased by approximately 10%, and covalent mixing between Th 6d t2g and O 2p orbitals is substantially reduced compared to that of pure ThO2.
RESUMO
BACKGROUND Baclofen is approved by the US FDA to treat spasticity, but its sustained use may cause drug addiction. The objective of this study was to compare the efficacy and safety of botulinum toxin type A versus baclofen in spasticity. MATERIAL AND METHODS A total of 336 patients who had spasticity caused by spinal cord injury were enrolled in a randomized (in 1: 1: 1: ratio) for placebo, controlled trial. Patients had received baclofen (BA group, n=112), local intramuscular injection of 500 U Botulinum toxin type A (BTI group, n=112), or physical therapies alone (placebo group, n=112). Modified Ashworth scale (mAS) score, disability assessment scale (DAS) score, modified medical research council (mMRC) score, the Barthel Index (BI) score, and treatment-emergent adverse effects were evaluated during the follow-up period. Wilcoxon test or one-way ANOVA/Tukey post hoc tests were performed at 95% of confidence level. RESULTS Baclofen (1.504±0.045 vs. 1.53±0.06, p=0.003, q=4.068) and botulinum toxin type A (1.49±0.09 vs. 1.528±0.15, p=0.0224, q=3.5541) had improved mAS scores after 2 weeks. Baclofen had a more strongly improved DAS score than botulinum toxin type A at 4 (p=0.0496, q=3.48) and 6 (p<0.0001, q=6.48) weeks. Baclofen and botulinum toxin type A had consistently improved BI scores. Baclofen caused asthenia and sleepiness, while botulinum toxin type A caused bronchitis and elevated blood pressure. CONCLUSIONS Botulinum toxin type A may be an effective therapeutic option for spasticity caused by spinal cord injury.
Assuntos
Toxinas Botulínicas Tipo A/uso terapêutico , Espasticidade Muscular/tratamento farmacológico , Traumatismos da Medula Espinal/tratamento farmacológico , Adulto , Baclofeno/efeitos adversos , Baclofeno/uso terapêutico , Toxinas Botulínicas Tipo A/efeitos adversos , Feminino , Humanos , Injeções Intramusculares , Masculino , Espasticidade Muscular/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologiaRESUMO
The 5' terminus of trypanosome mRNA is protected by a hypermethylated cap 4 derived from spliced leader (SL) RNA. Trypanosoma brucei nuclear capping enzyme with cap guanylyltransferase and methyltransferase activities (TbCgm1) modifies the 5'-diphosphate RNA (ppRNA) end to generate an m7G SL RNA cap. Here we show that T. brucei cytoplasmic capping enzyme (TbCe1) is a bifunctional 5'-RNA kinase and guanylyltransferase that transfers a γ-phosphate from ATP to pRNA to form ppRNA, which is then capped by transfer of GMP from GTP to the RNA ß-phosphate. A Walker A-box motif in the N-terminal domain is essential for the RNA kinase activity and is targeted preferentially to a SL RNA sequence with a 5'-terminal methylated nucleoside. Silencing of TbCe1 leads to accumulation of uncapped mRNAs, consistent with selective capping of mRNA that has undergone trans-splicing and decapping. We identify T. brucei mRNA decapping enzyme (TbDcp2) that cleaves m7GDP from capped RNA to generate pRNA, a substrate for TbCe1. TbDcp2 can also remove GDP from unmethylated capped RNA but is less active at a mature cap 4 end and thus may function in RNA cap quality surveillance. Our results establish the enzymology and relevant protein catalysts of a cytoplasmic recapping pathway that has broad implications for the functional reactivation of processed mRNA ends.
Assuntos
Metilação de DNA/fisiologia , Endorribonucleases/metabolismo , Nucleotidiltransferases/metabolismo , Proteínas de Protozoários/metabolismo , Capuzes de RNA/metabolismo , RNA Mensageiro/metabolismo , Trypanosoma brucei brucei/metabolismo , Regiões 5' não Traduzidas/genética , Clonagem Molecular , Endorribonucleases/genética , Microscopia de Fluorescência , Oligonucleotídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trypanosoma brucei brucei/genéticaRESUMO
p53 inactivation is a hallmark in non-small-cell lung cancer (NSCLC). It is therefore highly desirable to develop tumor-specific treatment for NSCLC therapy by restoring p53 function. Herein, a novel naphthalimide compound, NA-17, was identified as a promising drug candidate in view of both its anticancer activity and mechanism of action. NA-17 exhibited strong anticancer activity on a broad range of cancer cell lines but showed low toxicity to normal cell lines, such as HL-7702 and WI-38. Moreover, NA-17 showed p53-dependent inhibition selectivity in different NSCLC cell lines due to the activation state of endogenous p53 in the background level. Further studies revealed that NA-17 caused cell cycle arrest at the G1 phase, changed cell size, and induced apoptosis and cell death by increasing the proportion of sub-G1 cells. Molecular mechanism studies suggested that targeted accumulation of phospho-p53 in mitochondria and nuclei induced by NA-17 resulted in activation of Bak and direct binding of phospho-p53 to the target DNA sequences, thereby evoking cell apoptosis and cell cycle arrest and eventually leading to irreversible cancer cell inhibition. This work provided new insights into the molecular interactions and anticancer mechanisms of phospho-p53-dependent naphthalimide compounds.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Naftalimidas , Transcrição Gênica/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G1 do Ciclo Celular/genética , Células Hep G2 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Células MCF-7 , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Naftalimidas/química , Naftalimidas/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína bcl-X/genéticaRESUMO
Mycobacterium tuberculosis (Mtb) relies on a specialized set of metabolic pathways to support growth in macrophages. By conducting an extensive, unbiased chemical screen to identify small molecules that inhibit Mtb metabolism within macrophages, we identified a significant number of novel compounds that limit Mtb growth in macrophages and in medium containing cholesterol as the principle carbon source. Based on this observation, we developed a chemical-rescue strategy to identify compounds that target metabolic enzymes involved in cholesterol metabolism. This approach identified two compounds that inhibit the HsaAB enzyme complex, which is required for complete degradation of the cholesterol A/B rings. The strategy also identified an inhibitor of PrpC, the 2-methylcitrate synthase, which is required for assimilation of cholesterol-derived propionyl-CoA into the TCA cycle. These chemical probes represent new classes of inhibitors with novel modes of action, and target metabolic pathways required to support growth of Mtb in its host cell. The screen also revealed a structurally-diverse set of compounds that target additional stage(s) of cholesterol utilization. Mutants resistant to this class of compounds are defective in the bacterial adenylate cyclase Rv1625/Cya. These data implicate cyclic-AMP (cAMP) in regulating cholesterol utilization in Mtb, and are consistent with published reports indicating that propionate metabolism is regulated by cAMP levels. Intriguingly, reversal of the cholesterol-dependent growth inhibition caused by this subset of compounds could be achieved by supplementing the media with acetate, but not with glucose, indicating that Mtb is subject to a unique form of metabolic constraint induced by the presence of cholesterol.
Assuntos
Antituberculosos/farmacologia , Colesterol/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Macrófagos/microbiologia , Mycobacterium tuberculosis/metabolismo , Adenilil Ciclases/genética , Animais , Proteínas de Bactérias/metabolismo , Linhagem Celular , AMP Cíclico/metabolismo , Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Espaço Intracelular , Macrófagos/imunologia , Camundongos , Testes de Sensibilidade Microbiana , Oxigenases de Função Mista/antagonistas & inibidores , Mycobacterium tuberculosis/crescimento & desenvolvimento , Oxo-Ácido-Liases/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Tuberculose Pulmonar/tratamento farmacológicoRESUMO
A new iron(III) complex (1) of 5-nitro-8-hydroxylquinoline (HNOQ) was synthesized and structurally characterized in its solid state and solution state by IR, UV-Vis, electrospray ionization (ESI)-MS, elemental analysis, conductivity and X-ray single crystal diffraction analysis. The DNA binding study suggested that complex 1 interacted with calf thymus (ct)-DNA mainly via an intercalative binding mode. By 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the in vitro cytotoxicity of complex 1, comparing with HNOQ and cisplatin, was screened towards a series of tumor cell lines as well as the normal liver cell line HL-7702. Complex 1 showed higher cytotoxicity towards the tested tumor cell lines but lower cytotoxicity towards HL-7702 than HNOQ, in which the T-24 was the most sensitive cell line for 1. Complex 1 caused G2 phase cell cycle arrest and induced cell apoptosis in T-24 cells in a dose-dependent mode, evidenced by changes in cell morphology. Targeting the mitochondrial pathway due to the redox potential of Fe(III)/Fe(II), the apoptotic mechanism in T-24 cells treated by 1 was investigated by reactive oxygen species (ROS) detection, intracellular [Ca(2+)] measurement and caspase-9 and caspase-3 activity assay. It suggested that complex 1 induced cell apoptosis by triggering the caspase-9 and caspase-3 activation via a mitochondrion-mediated pathway.
Assuntos
Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Ferro/química , Quinolinas/química , Quinolinas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Cálcio/metabolismo , Caspase 3/metabolismo , Caspase 9/metabolismo , Bovinos , Linhagem Celular , Cisplatino/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Cristalografia por Raios X , DNA/química , DNA/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Conformação Molecular , Espécies Reativas de Oxigênio/metabolismo , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
A new platinum(II) complex of salphen derivative, namely Schiff base ligand that derived from o-phenylenediamine and 5-chlorosalicylaldehyde was synthesized. The complex possessed a planar mononuclear structure. The in vitro cytotoxicities of the complex were evaluated by microculture tetrozolium (MTT) assay against seven human tumor cell lines with the IC50 values of ca. 11.61 µM. Cell cycle analysis indicated that the complex induced apoptosis and G1-phase arrest in A549 cells. The results of colony formation assay showed that the complex could suppress the proliferation and viability of A549 cells. The binding of the complex to potential target DNA were investigated by fluorescence spectroscopy, viscosity measurements, fluorescence polarization and agarose gel electrophoresis. The results suggest that the most probable binding mode of the complex is intercalation.
Assuntos
Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , DNA/química , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Bases de Schiff/química , Bases de Schiff/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cristalização , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Compostos Organoplatínicos/síntese química , Ensaio Tumoral de Célula-TroncoRESUMO
In this paper, a multi-objective cooperative (MOC) controller based on average consensus algorithm is designed to achieve rapid State-of-Charge (SoC) balancing, proportional load current sharing, and flexible DC bus voltage regulation for parallel battery storage units (BSUs) in shipboard DC microgrids. Different from the conventional secondary controllers, the designed MOC controller can simultaneously achieve the above three control objectives with a fully distributed manner without requiring multiple controllers, thereby effectively improving the system stability and reducing the communication burden. Furthermore, an optimized convergence factor is designed to accelerate SoC balancing, and pinning control is introduced to obtain flexible and accurate DC bus voltage regulation. The process of SoC balancing and current sharing analysis, SoC convergence performance analysis, large-signal stability analysis, and global steady-state analysis verifies the rationality and stability of the MOC controller. Finally, the Matlab/Simulink simulation and StarSim HIL experimental results demonstrate the effectiveness and robustness of the designed MOC controller in a shipboard DC microgrid under various testing scenarios.
RESUMO
Marbofloxacin (MB) is a newly developed fluoroquinolone antibiotic used especially as a veterinary drug. It may be regarded as the improved version of enrofloxacin owing to its antibacterial activity, enhanced bioavailability, and pharmacokinetic-pharmacodynamic (PK-PD) properties. In this study, nine heavy rare-earth ions (Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were selected in light of their potential antibacterial activity and satisfactory biosafety to afford the corresponding rare-earth metal complexes of MB: the MB-Ln series. Their chemical structures and coordination patterns were characterized using IR spectroscopy, HRMS, TGA, and X-ray single-crystal diffraction analysis. Our results confirmed that all the MB-Ln complexes yielded the coincident coordination modes with four MB ligands coordinating to the Ln(III) center. In vitro antibacterial screening on five typical bacteria strains revealed that the MB-Ln complexes exhibited antibacterial activities comparable with MB, as indicated by the MIC/MBC values, in which Escherichia coli and Salmonella typhi were the most sensitive ones to MB-Ln. Furthermore, the MB-Ln complexes were found to be much less toxic in vivo than MB, as suggested by the evaluated LD50 (50% lethal dose) values. All the MB-Ln series complexes fell in the LD50 range of 5000-15 000 mg kg-1, while the LD50 value of MB was only 1294 mg kg-1. Furthermore, MB-Lu, as the selected representative of MB-Ln, could effectively inhibit the activity of DNA gyrase, the same as MB, suggesting the primary antibacterial mechanism of the MB-Ln series. The results demonstrated the good prospects and potential of metal-based veterinary drugs with better drug performance.
Assuntos
Metais Terras Raras , Drogas Veterinárias , Estrutura Molecular , Metais Terras Raras/farmacologia , Metais Terras Raras/química , Fluoroquinolonas/farmacologia , Antibacterianos/farmacologia , Íons/químicaRESUMO
BACKGROUND: As an unconventional subpopulation of T lymphocytes, γδ T cells can recognize antigens independently of major histocompatibility complex restrictions. Recent studies have indicated that γδ T cells play contrasting roles in tumor microenvironments-promoting tumor progression in some cancers (eg, gallbladder and leukemia) while suppressing it in others (eg, lung and gastric). γδ T cells are mainly enriched in peripheral mucosal tissues. As the cervix is a mucosa-rich tissue, the role of γδ T cells in cervical cancer warrants further investigation. METHODS: We employed a multiomics strategy that integrated abundant data from single-cell and bulk transcriptome sequencing, whole exome sequencing, genotyping array, immunohistochemistry, and MRI. RESULTS: Heterogeneity was observed in the level of γδ T-cell infiltration in cervical cancer tissues, mainly associated with the tumor somatic mutational landscape. Definitely, γδ T cells play a beneficial role in the prognosis of patients with cervical cancer. First, γδ T cells exert direct cytotoxic effects in the tumor microenvironment of cervical cancer through the dynamic evolution of cellular states at both poles. Second, higher levels of γδ T-cell infiltration also shape the microenvironment of immune activation with cancer-suppressive properties. We found that these intricate features can be observed by MRI-based radiomics models to non-invasively assess γδ T-cell proportions in tumor tissues in patients. Importantly, patients with high infiltration levels of γδ T cells may be more amenable to immunotherapies including immune checkpoint inhibitors and autologous tumor-infiltrating lymphocyte therapies, than to chemoradiotherapy. CONCLUSIONS: γδ T cells play a beneficial role in antitumor immunity in cervical cancer. The abundance of γδ T cells in cervical cancerous tissue is associated with higher response rates to immunotherapy.
Assuntos
Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/terapia , Microambiente Tumoral , Multiômica , Imunoterapia , PrognósticoRESUMO
The reaction of 4-chloro-2-(quinolin-8-yl-imino-meth-yl)phenol (HClQP) with cobalt(II) dichloride hexa-hydrate in methanol/chloro-form under solvothermal conditions yielded the title compound, [Co(C16H10ClN2O)2][CoCl3(CH3OH)]. The Co(III) atom is six-coordinated in a slightly distorted octa-hedral geometry by four N atoms and two O atoms of two tridentate HClQP ligands, which are nearly perpendicular to each other, making a dihedral angle of 86.95°. The Co(II) atom is four-coordinated by three Cl atoms and one O atom from a methanol ligand in a distorted tetra-hedral geometry. The crystal packing is consolidated by inter-molecular O-Hâ¯Cl, C-Hâ¯Cl and C-Hâ¯O hydrogen bonds, forming a three-dimensional supra-molecular structure, in which [Co(II)Cl3(CH3OH)] anions are connected via O-Hâ¯Cl and C-Hâ¯Cl hydrogen bonds into centrosymmetric dimers. Neighboring cobalt(III) complexes form dimers through C-Hâ¯O hydrogen bonds, as well as π-π stacking [centroid-centroid distances = 3.30â (2)â Å] between the planar quinoline systems of one HClQP ligand and the phenolate ring of another.
RESUMO
The conversion of biomass faces the challenge of mass and heat transfer, as well as the exertion of heterogeneous catalyst, because raw biomass exists usually in solid state. In this work, the simultaneous transformation and dissolution of the three main components (hemicellulose, cellulose, lignin) in corn straw were achieved in ethanol/ valerolactone (GVL)/H2 O (10 : 10 : 40, v/v/v) co-solvent system. With the assistance of AlCl3 â 6H2 O, the conversion of hemicellulose, lignin and cellulose was >96 % at 170 °C. The conversion of solid biomass into fluid, overcoming the mass transfer restrictions between solid biomass and solid catalysts, provides new raw materials to further upgrading. H2 O could penetrate inside the crystalline cellulose to swell even dissolve it, while ethanol and GVL acted as media to dissolve especially the G unit in lignin. The H+ derived from AlCl3 â 6H2 O hydrolysis could break the linkages of lignin-hemicellulose and glycosidic bond in saccharides, and aluminum chloride promoted the next degradation of polysaccharides to small molecules. Consequently, as high as 33.2 % yield of levulinic acid and 42.2 % yield of furfural were obtained. The cleavage of ß-O-4 and Cß -Cγ bonds in lignin produced large amounts of lignin-derived dimers and trimers. The total yield of monomeric phenols is up to 8 %.