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1.
J Comput Chem ; 45(27): 2318-2324, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38872590

RESUMO

Due to the potential applications in next-generation micro/nano electronic devices and functional materials, magnetic germanium (Ge)-based clusters are receiving increasing attention. In this work, we reported the structures, electronic and magnetic properties of CrMnGen with sizes n = 3-20. Transition metals (TMs) of Cr and Mn tend to stay together and be surrounded by Ge atoms. Small sized clusters with n ≤ 8 prefer to adopt bipyramid-based structures as the motifs with the excess Ge atoms absorbed on the surface. Starting from n = 9, the structure with one TM atom interior appears and persists until n = 16, and for larger sizes n = 17-20, the two TM atoms are full-encapsulated by Ge atoms to form endohedral structures. The Hirshfeld population analyses show that Cr atom always acts as the electron donor, while Mn atom is always the acceptor except for sizes 3 and 6. The average binding energies of these clusters increase with cluster size n, sharing a very similar trend as that of CrMnSin (n = 4-20) clusters, which indicates that it is favorable to form large-sized clusters. CrMnGen (n = 6, 13, 16, 19, and 20) clusters prefer to exhibit ferromagnetic Cr-Mn coupling, while the remaining clusters are ferrimagnetic.

2.
Small ; : e2403777, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39039987

RESUMO

Bicontinuous porous materials, which possess 3D interconnected network and pore channels facilitating the mass diffusion to the interior of materials, have demonstrated their promising potentials in a large variety of research fields. However, facile construction of such complex and delicate structures is still challenging. Here, an amine-mediated polymerization-induced fusion assembly strategy is reported for synthesizing polyphenol-based bicontinuous porous spheres with various pore structures. Specifically, the fusion of pore-generating template observed by TEM promotes the development of bicontinuous porous networks that are confirmed by 3D reconstruction. Furthermore, the resultant bicontinuous porous carbon particles after pyrolysis, with a diameter of ≈600 nm, a high accessible surface area of 359 m2 g-1, and a large pore size of 40-150 nm manifest enhanced performance toward the catalytic degradation of sulfamethazine in water decontamination. The present study expands the toolbox of interfacial tension-solvent-dependent porous spheres while providing new insight into their structure-property relationships.

3.
PLoS Pathog ; 18(12): e1011027, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36469533

RESUMO

Pseudomonas aeruginosa, a major inhabitant of numerous environmental reservoirs, is a momentous opportunistic human pathogen associated with severe infections even death in the patients suffering from immune deficiencies or metabolic diseases. Type III secretion system (T3SS) employed by P. aeruginosa to inject effector proteins into host cells is one of the pivotal virulence factors pertaining to acute infections caused by this pathogen. Previous studies showed that P. aeruginosa T3SS is regulated by various environmental cues such as calcium concentration and the host signal spermidine. However, how T3SS is regulated and expressed particularly under the ever-changing environmental conditions remains largely elusive. In this study, we reported that a tRNA modification enzyme PA3980, designated as MiaB, positively regulated T3SS gene expression in P. aeruginosa and was essential for the induced cytotoxicity of human lung epithelial cells. Further genetic assays revealed that MiaB promoted T3SS gene expression by repressing the LadS-Gac/Rsm signaling pathway and through the T3SS master regulator ExsA. Interestingly, ladS, gacA, rsmY and rsmZ in the LadS-Gac/Rsm signaling pathway seemed potential targets under the independent regulation of MiaB. Moreover, expression of MiaB was found to be induced by the cAMP-dependent global regulator Vfr as well as the spermidine transporter-dependent signaling pathway and thereafter functioned to mediate their regulation on the T3SS gene expression. Together, these results revealed a novel regulatory mechanism for MiaB, with which it integrates different environmental cues to modulate T3SS gene expression in this important bacterial pathogen.


Assuntos
Pseudomonas aeruginosa , Sistemas de Secreção Tipo III , Humanos , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo , Pseudomonas aeruginosa/metabolismo , Regulação Bacteriana da Expressão Gênica , Sinais (Psicologia) , Espermidina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , RNA de Transferência/metabolismo
4.
Chemphyschem ; 25(4): e202300800, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38083816

RESUMO

In this work, an unbiased global search with a homemade genetic algorithm was performed to investigate the structural evolution and electronic properties of Snx - (x=21-35) clusters with density functional theory (DFT) calculations. All the ground-state structures for all these Snx - (x=21-35) clusters have been confirmed by the comparison of the experimental and simulated photoelectron spectra (PESs). It has been revealed that all Snx - (x=21-35) clusters are tricapped trigonal prism (TTP)-based structures consisting of two (for sizes x=21-28) or three (for x=29-35) TTP units, with the remaining atoms adsorbed on the surface or inserted between TTP units. The gradually decreasing HOMO-LUMO gaps indicate that these clusters are undergoing semiconductor-to-metal transformation. The average binding energies show that the structural stabilities of Snx - clusters are not as good as that of silicon and germanium clusters. It found that sizes x=23, 25, 29, 33 show high relative stability.

5.
J Phys Chem A ; 128(14): 2737-2742, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38566323

RESUMO

The trend toward further miniaturization of micronano antiferromagnetic (AFM) spintronic devices has led to a strong demand for low-dimensional materials. The assembly of AFM clusters to produce such materials is a potential pathway that promotes studies on such clusters. In this work, we report on the discovery of the AFM Cr2Snx (x = 3-20) clusters with a stepwise growth at the density functional theory (DFT) level. In comparison, the two Cr atoms tend to stay together and be buried by Sn atoms, forming endohedral structures with one Cr atom encapsulated at size 9 and finally forming a full-encapsulated structure at size 17. Each successive cluster size is composed of its predecessor with an extra Sn atom adsorbed onto the face, giving evidence of stepwise growth. All these Cr2Snx (x = 3-20) clusters are antiferromagnets, except for the triplet-state ferrimagnetic Cr2Sn11, and all their singly negatively and positively charged ions are ferromagnets. The found stable Cr2Sn17 cluster can dimerize, yielding dimers and trimers without noticeably distorting the geometrical structure and magnetic properties of each of its constituent cluster monomers, making it possible as a building block for AFM materials.

6.
Bioorg Chem ; 153: 107832, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39317039

RESUMO

The genome sequencing of Aspergillus terreus reveals that the vast number of predicted biosynthetic gene clusters have not reflected by the metabolic profile observed under conventional culture conditions. In this study, a silent azaphilone biosynthetic gene cluster was activated by overexpressing a pathway-specific transcription factor gene2642 in marine-derived fungus A. terreus RA2905. Consequently, twenty azaphilone compounds were identified from the OE2642 mutant, including 11 new azaphilones and their precursors, azasperones C-J (1-5, 7-9) and preazasperones A-C (15-17). The structures of those new compounds were unambiguously determined on the basis of NMR and HRESIMS spectra analysis, and the absolute configurations were established depending on ECD calculations. Compounds 1 and 2 were the rarely reported naturally occurring azaphilones with 2-N coupled phenyl-derivative. The bioactivity assay revealed that compounds 18-20 exhibited significant anti-inflammatory activity. Based on the occurrence of diverse intermediates and the putative gene functions, a plausible biosynthetic pathway of these compounds was proposed. The above results demonstrated that overexpression of the pathway-specific transcription factor presents a promising approach for enriching fungal secondary metabolites and accelerating the targeted discovery of novel biosynthetic products.

7.
J Am Chem Soc ; 145(9): 5310-5319, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36758639

RESUMO

Herein, we report a versatile solvent-mediated polymerization-induced self-assembly (PISA) strategy to directly synthesize highly N-doped hierarchically porous structured carbon spheres with a tunable meso-macroporous configuration. The introduction of intermolecular hydrogen bonds is verified to enhance the interfacial interactions between block copolymers, oil droplets, and polyphenols. Moreover, the dominant hydrogen-bond-driven interactions can be systematically manipulated by selecting different cosolvent systems to generate diverse porous structures from the transformation of micellar and precursor co-assembly. Impressively, hierarchically structured meso-macroporous N-doped carbon spheres present simultaneously tunable sphere sizes and mesopores and macropores, ranging from 1.2 µm, 9/50 and 227 nm to 1.0 µm, 40, and 183 nm and 480, 24, and 95 nm. As a demonstration, dendritic-like N-doped hierarchically meso-macroporous carbon spheres manifest excellent enzyme-like activity, which is attributed to the continuous mass transport from the multiordered porosity. The current study provides a new platform for the synthesis of novel well-defined porous materials.

8.
Inorg Chem ; 62(19): 7360-7365, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37130241

RESUMO

Controllable modulation strategies between one-dimensional (1D) and two-dimensional (2D) structures have been rarely reported for metal-organic frameworks (MOFs). Here, 1D, 1D/2D, and 2D Ni-MOFs can be facilely prepared by adjusting the ratio of Ni2+ and the pyromellitic acid linker. A low-dimensional structure can shorten the transmission distance, while MOFs with a high Ni2+ content can supply rich active sites for oxidation-reduction reactions. The 2D structure Ni-MOF with an optimized Ni2+/pyromellitic acid ratio presents a good performance of 1036 F g-1 at a current density of 1 A g-1 with a comparable rate performance of 62% at 20 A g-1. The study may offer a facile design to control the structure of MOFs for employing in electrochemical energy storage.

9.
Mar Drugs ; 21(3)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36976240

RESUMO

Previously, we identified a series of steroids (1-6) that showed potent anti-virus activities against respiratory syncytial virus (RSV), with IC50 values ranging from 3.23 to 0.19 µM. In this work, we first semi-synthesized and characterized the single isomer of 5, 25(R)-26-acetoxy-3ß,5α-dihydroxycholest-6-one, named as (25R)-5, in seven steps from a commercially available compound diosgenin (7), with a total yield of 2.8%. Unfortunately, compound (25R)-5 and the intermediates only showed slight inhibitions against RSV replication at the concentration of 10 µM, but they possessed potent cytotoxicity activities against human bladder cancer 5637 (HTB-9) and hepatic cancer HepG2, with IC50 values ranging from 3.0 to 15.5 µM without any impression of normal liver cell proliferation at 20 µM. Among them, the target compound (25R)-5 possessed cytotoxicity activities against 5637 (HTB-9) and HepG2 with IC50 values of 4.8 µM and 15.5 µM, respectively. Further studies indicated that compound (25R)-5 inhibited cancer cell proliferation through inducing early and late-stage apoptosis. Collectively, we have semi-synthesized, characterized and biologically evaluated the 25R-isomer of compound 5; the biological results suggested that compound (25R)-5 could be a good lead for further anti-cancer studies, especially for anti-human liver cancer.


Assuntos
Antineoplásicos , Diosgenina , Esteroides/farmacologia , Diosgenina/farmacologia , Antineoplásicos/farmacologia , Proliferação de Células , Estrutura Molecular
10.
Clin Oral Investig ; 28(1): 4, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123880

RESUMO

OBJECTIVES: Skeletal class II malocclusion is one of the most common malocclusions. Among the functional appliances for skeletal class II malocclusion, the Twin-Block appliance with a maxillary expander is effective in repositioning the mandible forward. In this study, we focused our efforts on investigating the effects of Twin-Block appliances with maxillary expanders on the upper airway in growing children with skeletal class II malocclusion by tracing and measuring lateral cephalograms after evaluating the consistency of three-dimensional CBCT data and two-dimensional lateral cephalogram data. MATERIALS AND METHODS: A total of 102 patients ranging from 9 to 15 years old (11.37 ± 2.80, male/female ratio = 1:1) with skeletal class II malocclusion were selected to evaluate the consistency of CBCT data and lateral cephalogram data. The strongly and moderately correlated segments were then selected to study the effects of Twin-Block with a maxillary expander on the upper airway in 66 growing children with skeletal class II malocclusion (11.31 ± 1.23 years old, male/female ratio = 1:1) by lateral cephalograms. RESULTS: The results showed a strong significant correlation in the nasopharynx (r = 0.708) and moderate significant correlations in the overall upper airway (r = 0.641), palatopharynx (r = 0.553), and glossopharynx (r = 0.575) but a weak correlation in the hypopharynx (r = 0.323). The corresponding determination coefficient (R2) was also determined by scatter plot analysis. Moreover, compared with the pretreatment data (T1), the total area of the upper airway and the areas of the nasopharynx, palatopharynx, and glossopharynx after functional treatment (T2) increased statistically and significantly. CONCLUSIONS: Lateral cephalograms can reflect the volume of the nasopharynx and oropharynx in skeletal class II children to a certain extent, while Twin-Block appliances with maxillary expanders can widen the volume of the nasopharynx and oropharynx significantly. CLINICAL RELEVANCE: The lateral cephalogram is reliable for analyzing the nasopharynx, palatopharynx, and glossopharynx in orthodontic clinical practice. Twin-Block appliances with maxillary expanders have a positive effect on skeletal class II patients with airway stenosis.


Assuntos
Má Oclusão Classe II de Angle , Má Oclusão , Aparelhos Ortodônticos Funcionais , Criança , Humanos , Masculino , Feminino , Adolescente , Estudos Retrospectivos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/terapia , Nasofaringe , Mandíbula , Cefalometria/métodos
11.
Mol Plant Microbe Interact ; 35(5): 369-379, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35100009

RESUMO

The GacS-GacA type two-component system (TCS) positively regulates pathogenicity-related phenotypes in many plant pathogens. In addition, Dickeya oryzae EC1, the causative agent of soft rot disease, produces antibiotic-like toxins called zeamines as one of the major virulence factors that inhibit the germination of rice seeds. The present study identified a GacS-GacA type TCS, named TzpS-TzpA, that positively controls the virulence of EC1, mainly by regulating production of the toxin zeamines. RNA-seq analysis of strain EC1 and its tzpA mutant showed that the TCS regulated a wide range of virulence genes, especially those encoding zeamines. Protein-protein interaction was detected between TzpS and TzpA through the bacterial two-hybrid system and pull-down assay. In trans expression of tzpA failed to rescue the defective phenotypes in both the ΔtzpS and ΔtzpSΔtzpA mutants. Furthermore, TzpA controls target gene expression by direct binding to DNA promoters that contain a Gac-box motif, including a regulatory RNA rsmB and the vfm quorum-sensing system regulator vfmE. These findings therefore suggested that the EC1 TzpS-TzpA TCS system mediates the pathogenicity of Dickeya oryzae EC1 mainly by regulating the production of zeamines.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Proteínas de Bactérias , Dickeya , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Macrolídeos , Doenças das Plantas/microbiologia , Poliaminas , Virulência/genética
12.
Cancer Sci ; 113(11): 3722-3734, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36087034

RESUMO

Enhanced fatty acid synthesis provides proliferation and survival advantages for tumor cells. Apelin is an adipokine, which serves as a ligand of G protein-coupled receptors that promote tumor growth in malignant cancers. Here, we confirmed that apelin increased sterol regulatory element-binding protein 1 (SREBP1) activity and induced the expression of glutamine amidotransferase for deamidating high-mobility group A 1 (HMGA1) to promote fatty acid synthesis and proliferation of lung cancer cells. This post-translational modification stabilized the HMGA1 expression and enhanced the formation of the apelin-HMGA1-SREBP1 complex to facilitate SREBP1 activity for lipid metabolism and lung cancer cell growth. We uncovered the pivotal role of apelin-mediated deamidation of HMGA1 in lipid metabolism and tumorigenesis of lung cancer cells.


Assuntos
Proteína HMGA1a , Neoplasias Pulmonares , Humanos , Apelina , Carcinogênese/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Ácidos Graxos , Proteína HMGA1a/genética , Lipídeos , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
13.
Small ; 18(21): e2200656, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35466571

RESUMO

The insufficient contact between two phases in the heterostructure weakens the coupling interaction effect, which makes it difficult to effectively improve the electrochemical performance. Herein, a Co-carbonate hydroxide@ Ni-metal organic frameworks (Co-CH@Ni-MOFs) composite with super uniform core-shell heterostructure is fabricated by adopting 1D Co-CH nanowires as structuredirecting agents to induce the coating of Ni-MOFs. Both experimental and theoretical calculation results demonstrate that the heterostructure plays a vital role in the high performance of the as-prepared materials. On the one hand, the construction of super uniform core-shell heterostructure can create a large number of interfacial active sites and take advantages of the electrochemical characteristics of each component. On the other hand, the heterostructure can increase the adsorption energy of OH- ions and promote the electrochemical activity for improving the reversible redox reaction kinetics. Based on the aforementioned advantages, the as-fabricated Co-CH@Ni-MOFs electrode exhibits a high specific capacity of 173.1 mAh g-1 (1246 F g-1 ) at 1 A g-1 , an ultrahigh rate capability of 70.3% at 150 A g-1 and excellent cycling stability with 90.1% capacity retention after 10 000 cycles at 10 A g-1 . This study may offer a versatile design for fabricating a MOFs-based heterostructure as energy storage electrodes.

14.
Appl Environ Microbiol ; 88(2): e0165521, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-34731046

RESUMO

The type VI secretion system (T6SS) is an important translocation apparatus that is widely employed by Gram-negative bacteria to deliver toxic effectors into eukaryotic and prokaryotic target cells, causing host damage and providing competitive advantages in polymicrobial environments. The genome of Pseudomonas aeruginosa harbors three T6SS clusters (H1-T6SS, H2-T6SS, H3-T6SS). Activities of these systems are tightly regulated by a complicated signaling network which remains largely elusive. In this study, we focused on a previously characterized two-component system FleS/FleR, and performed comparative transcriptome analysis between the PAO1 wild-type strain and its isogenic ΔfleR mutant, which revealed the important role of FleS/FleR in regulating multiple physiological pathways including T6SS. Gene expression and bacterial killing assays showed that the expression and activity of H1-T6SS are repressed in the wild-type strain owing to the high intracellular c-di-GMP content. Further explorations demonstrated that c-di-GMP relies on the transcription factor FleQ to repress H1-T6SS and its synthesis is controlled by a global regulator AmrZ which is induced by the active FleS/FleR. Interestingly, repression of H1-T6SS by FleS/FleR in PAO1 is independent of RetS which is known to regulate H1-T6SS by controlling the central post-transcriptional factor RsmA. Together, our results identified a novel regulator of H1-T6SS and provided detailed mechanisms of this signaling pathway in PAO1. IMPORTANCE Pseudomonas aeruginosa is an opportunistic human pathogen distributed widely in the environment. The genome of this pathogen contains three T6SS clusters which contribute significantly to its virulence. Understanding the complex regulatory network that controls the activity of T6SS is essential for the development of effective therapeutic treatments for P. aeruginosa infections. In this study, transcriptome analysis led to the identification of a novel regulator FleS/FleR which inversely regulates H1-T6SS and H2-T6SS in P. aeruginosa PAO1. We further revealed a detailed FleS/FleR-mediated regulatory pathway of H1-T6SS in PAO1 which involves two additional transcriptional regulators AmrZ and FleQ and the second messenger c-di-GMP, providing important implications to develop novel anti-infective strategies and antimicrobial drugs.


Assuntos
Pseudomonas aeruginosa , Sistemas de Secreção Tipo VI , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , GMP Cíclico/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Pseudomonas aeruginosa/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo , Virulência/genética
15.
Biomacromolecules ; 23(1): 140-149, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34910461

RESUMO

A facile and general strategy for preparing uniform and multifunctional polyphenol-based colloidal particles through amine-catalyzed polymerization-induced self-assembly is described. The size and interfacial adhesion of polyphenol spheres can be easily controlled over a wide range via adjusting the concentration of the cosolvent and monomer. Moreover, the polyphenol spheres showed excellent thermal and chemical stability and highly active properties and could efficiently deplete the reactive oxygen species (ROS), which are helpful for in vivo ROS regulation for inflammatory therapeutic. The accessible and versatile method provides a feasible way for the rational engineering of multifunctional polyphenol spheres, which have great potential in many fields.


Assuntos
Aminas , Polifenóis , Catálise , Polimerização
16.
Clin Lab ; 68(3)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35254033

RESUMO

BACKGROUND: Plasma cell myeloma is a kind of multifocal proliferation of neoplastic plasma cells in bone marrow. Morphology of myeloma plasma cells varies from mature to immature form, plasmablastic, and pleomorphic cells, with the proportion of plasma cells changing from a slight increase to > 90%. Several morphologic variants of PCM have been reported. METHODS: Herein, we present a rare case of PCM with typical morphological features of bone marrow metastatic carcinoma, association with CD138 positivity, and a complex karyotype. RESULTS: The diagnosis of PCM was made based on a combination of the clinical features, morphology, immunofixation electrophoresis, flow cytometry immunophenotyping, and bone marrow biopsy. Overall, the result was in accord with PCM based on the WHO classification. CONCLUSIONS: The case focuses on the wide morphological variants of PCM and highlights the reason why PCM should be taken as a differential diagnosis when one presents with typical morphological feature and common antigens expression of bone marrow metastatic carcinoma.


Assuntos
Carcinoma , Mieloma Múltiplo , Medula Óssea , Carcinoma/metabolismo , Citometria de Fluxo/métodos , Humanos , Imunofenotipagem , Plasmócitos/metabolismo , Plasmócitos/patologia
17.
Clin Lab ; 68(9)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36125146

RESUMO

BACKGROUND: Deficiency of vitamin B(12) or folate causes megaloblastic anemia (MA). The disease presents with pancytopenia due to the excessive cellular apoptosis of hematopoietic progenitor. MA is characterized by the presence of high mean corpuscular volume in the blood routine test and hyperlobulation nuclei of the granulocytes in the peripheral blood smears, and megaloblasts in the bone marrow. METHODS: We report a rare case, in which megaloblastic anemia was masked by an unrecognized hemoglobinopathy and presented with normocytic anemia and atypical morphological features of bone marrow. RESULTS: The patient was finally diagnosed with coexistence of MA and a-thalassemia minor due to determination of folate deficiency and genetic mutation for a-thalassemia. CONCLUSIONS: The case focuses on the contribution of the peripheral circulating blood smear examination in the diagnosis of anemia.


Assuntos
Anemia Megaloblástica , Deficiência de Ácido Fólico , Talassemia , Anemia Megaloblástica/complicações , Anemia Megaloblástica/diagnóstico , Ácido Fólico , Deficiência de Ácido Fólico/complicações , Deficiência de Ácido Fólico/diagnóstico , Humanos , Vitaminas
18.
Mar Drugs ; 20(3)2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35323491

RESUMO

Pseudomonas aeruginosa, one of the most intractable Gram-negative bacteria, has become a public health threat due to its outer polysaccharide layer, efflux transporter system, and high level of biofilm formation, all of which contribute to multi-drug resistance. Even though it is a pathogen of the highest concern, the status of the antibiotic development pipeline is unsatisfactory. In this review, we summarize marine natural products (MNPs) isolated from marine plants, animals, and microorganisms which possess unique structures and promising antibiotic activities against P. aeruginosa. In the last decade, nearly 80 such MNPs, ranging from polyketides to alkaloids, peptides, and terpenoids, have been discovered. Representative compounds exhibited impressive in vitro anti-P. aeruginosa activities with MIC values in the single-digit nanomolar range and in vivo efficacy in infectious mouse models. For some of the compounds, the preliminary structure-activity-relationship (SAR) and anti-bacterial mechanisms of selected compounds were introduced. Compounds that can disrupt biofilm formation or membrane integrity displayed potent inhibition of multi-resistant clinical P. aeruginosa isolates and could be considered as lead compounds for future development. Challenges on how to translate hits into useful candidates for clinical development are also proposed and discussed.


Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Animais , Humanos
19.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188727

RESUMO

Brain-resident microglia and myeloid cells (perivascular macrophages) are important HIV reservoirs in vivo, especially in the central nervous system (CNS). Despite antiretroviral therapy (ART), low-level persistent HIV replication in these reservoirs remains detectable, which contributes to neuroinflammation and neurological disorders in HIV-infected patients. New approaches complementary to ART to repress residual HIV replication in CNS reservoirs are needed. Our group has recently identified a BRD4-selective small molecule modulator (ZL0580) that induces the epigenetic suppression of HIV. Here, we examined the effects of this compound on HIV in human myeloid cells. We found that ZL0580 induces potent and durable suppression of both induced and basal HIV transcription in microglial cells (HC69) and monocytic cell lines (U1 and OM10.1). Pretreatment of microglia with ZL0580 renders them more refractory to latent HIV reactivation, indicating an epigenetic reprogramming effect of ZL0580 on HIV long terminal repeat (LTR) in microglia. We also demonstrate that ZL0580 induces repressive effect on HIV in human primary monocyte-derived macrophages (MDMs) by promoting HIV suppression during ART treatment. Mechanistically, ZL0580 inhibits Tat transactivation in microglia by disrupting binding of Tat to CDK9, a process key to HIV transcription elongation. High-resolution micrococcal nuclease mapping showed that ZL0580 induces a repressive chromatin structure at the HIV LTR. Taken together, our data suggest that ZL0580 represents a potential approach that could be used in combination with ART to suppress residual HIV replication and/or latent HIV reactivation in CNS reservoirs, thereby reducing HIV-associated neuroinflammation.IMPORTANCE Brain-resident microglia and perivascular macrophages are important HIV reservoirs in the CNS. Persistent viral replication and latent HIV reactivation in the CNS, even under ART, are believed to occur, causing neuroinflammation and neurological disorders in HIV-infected patients. It is critical to identify new approaches that can control residual HIV replication and/or latent HIV reactivation in these reservoirs. We here report that the BRD4-selective small molecule modulator, ZL0580, induces potent and durable suppression of HIV in human microglial and monocytic cell lines. Using an in vitro HIV-infected, ART-treated MDM model, we show that ZL0580 also induces suppressive effect on HIV in human primary macrophages. The significance of our research is that it suggests a potential new approach that has utility in combination with ART to suppress residual HIV replication and/or HIV reactivation in CNS reservoirs, thereby reducing neuroinflammation and neurological disorders in HIV-infected individuals.


Assuntos
Antirreumáticos/farmacologia , Proteínas de Ciclo Celular/antagonistas & inibidores , Epigênese Genética/efeitos dos fármacos , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Infecções por HIV/metabolismo , HIV-1/fisiologia , Microglia , Monócitos , Fatores de Transcrição/antagonistas & inibidores , Replicação Viral/efeitos dos fármacos , Antirreumáticos/química , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Infecções por HIV/tratamento farmacológico , Infecções por HIV/patologia , Humanos , Microglia/metabolismo , Microglia/patologia , Microglia/virologia , Monócitos/metabolismo , Monócitos/patologia , Monócitos/virologia , Fatores de Transcrição/metabolismo
20.
Proc Natl Acad Sci U S A ; 115(28): E6404-E6410, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29946037

RESUMO

DNA-encoded libraries (DEL)-based discovery platforms have recently been widely adopted in the pharmaceutical industry, mainly due to their powerful diversity and incredible number of molecules. In the two decades since their disclosure, great strides have been made to expand the toolbox of reaction modes that are compatible with the idiosyncratic aqueous, dilute, and DNA-sensitive parameters of this system. However, construction of highly important C(sp3)-C(sp3) linkages on DNA through cross-coupling remains unexplored. In this article, we describe a systematic approach to translating standard organic reactions to a DEL setting through the tactical combination of kinetic analysis and empirical screening with information captured from data mining. To exemplify this model, implementation of the Giese addition to forge high value C-C bonds on DNA was studied, which represents a radical-based synthesis in DEL.


Assuntos
DNA/química , Biblioteca Gênica , Modelos Moleculares , Cinética
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