Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
EMBO Rep ; 24(8): e56635, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37358015

RESUMO

Sepsis is a leading cause of in-hospital mortality resulting from a dysregulated response to infection. Novel immunomodulatory therapies targeting macrophage metabolism have emerged as an important focus for current sepsis research. However, understanding the mechanisms underlying macrophage metabolic reprogramming and how they impact immune response requires further investigation. Here, we identify macrophage-expressed Spinster homolog 2 (Spns2), a major transporter of sphingosine-1-phosphate (S1P), as a crucial metabolic mediator that regulates inflammation through the lactate-reactive oxygen species (ROS) axis. Spns2 deficiency in macrophages significantly enhances glycolysis, thereby increasing intracellular lactate production. As a key effector, intracellular lactate promotes pro-inflammatory response by increasing ROS generation. The overactivity of the lactate-ROS axis drives lethal hyperinflammation during the early phase of sepsis. Furthermore, diminished Spns2/S1P signaling impairs the ability of macrophages to sustain an antibacterial response, leading to significant innate immunosuppression in the late stage of infection. Notably, reinforcing Spns2/S1P signaling contributes to balancing the immune response during sepsis, preventing both early hyperinflammation and later immunosuppression, making it a promising therapeutic target for sepsis.


Assuntos
Macrófagos , Sepse , Humanos , Proteínas de Transporte de Ânions/metabolismo , Terapia de Imunossupressão , Lactatos , Macrófagos/metabolismo , Espécies Reativas de Oxigênio/metabolismo
2.
Small ; 20(8): e2305990, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37821401

RESUMO

Halide composition engineering has been demonstrated as an effective strategy for optical and electronic properties modulation in 3D perovskites. While the impact of halide mixing on the structural and charge transport properties of 3D perovskitoids remains largely unexplored. Herein, it is demonstrated that bromine (Br) mixing in 3D (NMPDA)Pb2 I6 (NMPDA = N-methyl-1,3-propane diammonium) perovskitoid yields stabilized (NMPDA)Pb2 I4 Br2 with specific ordered halide sites, where Br ions locate at the edge-sharing sites. The halide ordered structure enables stronger H-bonds, shorter interlayer distance, and lower octahedra distortion in (NMPDA)Pb2 I4 Br2 with respect to the pristine (NMPDA)Pb2 I6 . These attributes further result in high ion migration activation energy, low defect states density, and enhanced carrier mobility-lifetime product (µτ), as underpinned by the electrical properties investigation and DFT calculations. Remarkably, the parallel configured photodetector based on (NMPDA)Pb2 I4 Br2 single crystal delivers a high on/off current ratio of 3.92 × 103 , a satisfying photoresponsivity and detectivity of 0.28 A W-1 and 3.05 × 1012 Jones under 10.94 µW cm-2 irradiation, superior to that of (NMPDA)Pb2 I6 and the reported 3D perovskitoids. This work sheds novel insight on exploring 3D mixed halide perovskitoids toward advanced and stable optoelectronic devices.

3.
Small ; : e2310591, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409636

RESUMO

The family of polar hybrid perovskites, in which bulk photovoltaic effects (BPVEs) drive steady photocurrent without bias voltage, have shown promising potentials in self-powered polarization-sensitive photodetection. However, reports of BPVEs in 3D perovskites remain scare, being mainly hindered by the limited dipole moment or lack of symmetry breaking. Herein, a polar 3D perovskitoid, (BDA)Pb2 Br6 (BDA = NH3 C4 H8 NH3 ), where the spontaneous polarization (Ps )-induced BPVE drives self-powered photodetection of polarized-light is reported. Emphatically, the edge-sharing Pb2 Br10 dimer building unit allows the optical anisotropy and polarity in 3D (BDA)Pb2 Br6 , which triggers distinct optical absorption dichroism ratio of ≈2.80 and BPVE dictated photocurrent of 3.5 µA cm-2 . Strikingly, these merits contribute to a polarization-sensitive photodetection with a high polarization ratio (≈4) under self-powered mode, beyond those of 2D hybrid perovskites and inorganic materials. This study highlights the potential of polar 3D perovskitoids toward intelligent optoelectronic applications.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38946401

RESUMO

BACKGROUND AND AIM: Liver stiffness measurements (LSMs) are promising for monitoring disease progression or regression. We assessed the prognostic significance of dynamic changes in LSM over time on liver-related events (LREs) and death in patients with chronic hepatitis B (CHB) and compensated advanced chronic liver disease (cACLD). METHODS: This retrospective study included 1272 patients with CHB and cACLD who underwent at least two measurements, including LSM and fibrosis score based on four factors (FIB-4). ΔLSM was defined as [(follow-up LSM - baseline LSM)/baseline LSM × 100]. We recorded LREs and all-cause mortality during a median follow-up time of 46 months. Hazard ratios (HRs) and confidence intervals (CIs) for outcomes were calculated using Cox regression. RESULTS: Baseline FIB-4, baseline LSM, ΔFIB-4, ΔLSM, and ΔLSM/year were independently and simultaneously associated with LREs (adjusted HR, 1.04, 95% CI, 1.00-1.07; 1.02, 95% CI, 1.01-1.03; 1.06, 95% CI, 1.03-1.09; 1.96, 95% CI, 1.63-2.35, 1.02, 95% CI, 1.01-1.04, respectively). The baseline LSM combined with the ΔLSM achieved the highest Harrell's C (0.751), integrated AUC (0.776), and time-dependent AUC (0.737) for LREs. Using baseline LSM and ΔLSM, we proposed a risk stratification method to improve clinical applications. The risk proposed stratification based on LSM performed well in terms of prognosis: low risk (n = 390; reference), intermediate risk (n = 446; HR = 3.38), high risk (n = 272; HR = 5.64), and extremely high risk (n = 164; HR = 11.11). CONCLUSIONS: Baseline and repeated noninvasive tests measurement allow risk stratification of patients with CHB and cACLD. Combining baseline and dynamic changes in the LSM improves prognostic prediction.

5.
Appl Microbiol Biotechnol ; 108(1): 226, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38381229

RESUMO

Terpenoids are a class of structurally complex, naturally occurring compounds found predominantly in plant, animal, and microorganism secondary metabolites. Classical terpenoids typically have carbon atoms in multiples of five and follow well-defined carbon skeletons, whereas noncanonical terpenoids deviate from these patterns. These noncanonical terpenoids often result from the methyltransferase-catalyzed methylation modification of substrate units, leading to irregular carbon skeletons. In this comprehensive review, various activities and applications of these noncanonical terpenes have been summarized. Importantly, the review delves into the biosynthetic pathways of noncanonical terpenes, including those with C6, C7, C11, C12, and C16 carbon skeletons, in bacteria and fungi host. It also covers noncanonical triterpenes synthesized from non-squalene substrates and nortriterpenes in Ganoderma lucidum, providing detailed examples to elucidate the intricate biosynthetic processes involved. Finally, the review outlines the potential future applications of noncanonical terpenoids. In conclusion, the insights gathered from this review provide a reference for understanding the biosynthesis of these noncanonical terpenes and pave the way for the discovery of additional unique and novel noncanonical terpenes. KEY POINTS: •The activities and applications of noncanonical terpenoids are introduced. •The noncanonical terpenoids with irregular carbon skeletons are presented. •The microbial biosynthesis of noncanonical terpenoids is summarized.


Assuntos
Terpenos , Triterpenos , Animais , Carbono , Metiltransferases , Processamento de Proteína Pós-Traducional
6.
Ann Hepatol ; 29(5): 101516, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38851395

RESUMO

INTRODUCTION AND OBJECTIVES: Assessing fibrosis risk noninvasively is essential. The steatosis-associated fibrosis estimator (SAFE) score shows promise but needs validation. PATIENTS AND METHODS: This was a three-part study. In part 1, we compared the SAFE score with the Fibrosis-4 (FIB-4) and NAFLD fibrosis score (NFS) in the National Health and Nutrition Examination Survey (NHANES) cohort (2017-2020), using transient elastography (TE) as screening reference. In part 2, we examined patients who underwent liver biopsies at an Asian center between 2018 and 2020 to assess these models in various liver diseases. In part 3, the SAFE score was applied to adults in the NHANES cohort (1999-2016) to assess the correlation with mortality. RESULTS: In part 1, we studied 6,677 patients, comprising 595 screening positive (TE ≥8 kPa). SAFE (cutoff 100) displayed a lower proportion of false positives (10.4 %) than FIB-4 (cutoff 1.3) and NFS (cutoff -1.455) (22.1 % and 43.6 %) while retaining a low proportion of false negatives (5.5 %). In part 2, SAFE outperformed FIB-4 (P = 0.04) and NFS (P = 0.04) in staging significant fibrosis (≥S2) in NAFLD and had similar accuracies in other etiologies. In part 3, the FIB-4, NFS, and SAFE score were associated with all-cause mortality in the general population, with c-statistics of 0.738, 0.736, and 0.759, respectively. CONCLUSIONS: The SAFE score reduced futile referrals more effectively than FIB-4 without raising the missed TE ≥ 8 kPa rate. It correlated with all-cause mortality in the general population and excelled in staging significant fibrosis in NAFLD.

7.
Microb Cell Fact ; 22(1): 76, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37085866

RESUMO

Central carbon metabolism (CCM), including glycolysis, tricarboxylic acid cycle and the pentose phosphate pathway, is the most fundamental metabolic process in the activities of living organisms that maintains normal cellular growth. CCM has been widely used in microbial metabolic engineering in recent years due to its unique regulatory role in cellular metabolism. Using yeast and Escherichia coli as the representative organisms, we summarized the metabolic engineering strategies on the optimization of CCM in eukaryotic and prokaryotic microbial chassis, such as the introduction of heterologous CCM metabolic pathways and the optimization of key enzymes or regulatory factors, to lay the groundwork for the future use of CCM optimization in metabolic engineering. Furthermore, the bottlenecks in the application of CCM optimization in metabolic engineering and future application prospects are summarized.


Assuntos
Carbono , Engenharia Metabólica , Carbono/metabolismo , Redes e Vias Metabólicas , Via de Pentose Fosfato , Ciclo do Ácido Cítrico , Escherichia coli/metabolismo , Saccharomyces cerevisiae/metabolismo
8.
Nanotechnology ; 34(37)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37311447

RESUMO

The design and construction of three-dimensional covalent organic frameworks (3D COF) remains a major challenge, and it is necessary to explore new strategies to synthesize 3D COF with ideal structure. Here, we utilize two-dimensional covalent organic framework (2D COF) with allyl side chain to achieve interlayer crosslinking through olefin metathesis reaction, thereby constructing a 3D COF with cage-like structures. This new material named CAGE-COF has larger specific surface area and more open pore structure than the original 2D COF. The cathode material with CAGE-COF retained 78.7% of its initial capacity after 500 cycles, and the fading rate is 0.04% each cycle.


Assuntos
Lítio , Estruturas Metalorgânicas , Eletrodos , Alcenos , Fontes de Energia Elétrica , Enxofre
9.
Appl Microbiol Biotechnol ; 107(11): 3391-3404, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37126085

RESUMO

Rare ginsenosides are the deglycosylated secondary metabolic derivatives of major ginsenosides, and they are more readily absorbed into the bloodstream and function as active substances. The traditional preparation methods hindered the potential application of these effective components. The continuous elucidation of ginsenoside biosynthesis pathways has rendered the production of rare ginsenosides using synthetic biology techniques effective for their large-scale production. Previously, only the progress in the biosynthesis and biotechnological production of major ginsenosides was highlighted. In this review, we summarized the recent advances in the identification of key enzymes involved in the biosynthetic pathways of rare ginsenosides, especially the glycosyltransferases (GTs). Then the construction of microbial chassis for the production of rare ginsenosides, mainly in Saccharomyces cerevisiae, was presented. In the future, discovery of more GTs and improving their catalytic efficiencies are essential for the metabolic engineering of rare ginsenosides. This review will give more clues and be helpful for the characterization of the biosynthesis and metabolic engineering of rare ginsenosides. KEY POINTS: • The key enzymes involved in the biosynthetic pathways of rare ginsenosides are summarized. • The recent progress in metabolic engineering of rare ginsenosides is presented. • The discovery of glycosyltransferases is essential for the microbial production of rare ginsenosides in the future.


Assuntos
Ginsenosídeos , Panax , Engenharia Metabólica , Ginsenosídeos/metabolismo , Panax/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Glicosiltransferases/genética , Glicosiltransferases/metabolismo
10.
Molecules ; 28(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37049981

RESUMO

To develop effective agents to combat bacterial infections, a series of thiourea derivatives (TDs) were prepared and their antibacterial activities were evaluated. Our results showed that TD4 exerted the most potent antibacterial activity against a number of Staphylococcus aureus (S. aureus), including the methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis and Enterococcus faecalis strains, with the minimum inhibitory concentration (MIC) at 2-16 µg/mL. It inhibited the MRSA growth curve in a dose-dependent manner and reduced the colony formation unit in 4× MIC within 4 h. Under the transmission electron microscope, TD4 disrupted the integrity of MRSA cell wall. Additionally, it reduced the infective lesion size and the bacterial number in the MRSA-induced infection tissue of mice and possessed a good drug likeness according to the Lipinski rules. Our results indicate that TD4 is a potential lead compound for the development of novel antibacterial agent against the MRSA infection.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Staphylococcus aureus , NAD/farmacologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Homeostase
11.
Molecules ; 28(6)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36985593

RESUMO

The emergence of antibiotic-resistant-bacteria is a serious public health threat, which prompts us to speed up the discovery of novel antibacterial agents. Phage display technology has great potential to screen peptides or antibodies with high binding capacities for a wide range of targets. This property is significant in the rapid search for new antibacterial agents for the control of bacterial resistance. In this paper, we not only summarized the recent progress of phage display for the discovery of novel therapeutic agents, identification of action sites of bacterial target proteins, and rapid detection of different pathogens, but also discussed several problems of this technology that must be solved. Breakthrough in these problems may further promote the development and application of phage display technology in the biomedical field in the future.


Assuntos
Infecções Bacterianas , Bacteriófagos , Doenças Transmissíveis , Humanos , Peptídeos/uso terapêutico , Peptídeos/química , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Anticorpos/uso terapêutico , Antibacterianos/uso terapêutico , Proteínas de Bactérias , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/tratamento farmacológico , Biblioteca de Peptídeos
12.
Molecules ; 28(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049901

RESUMO

Pseudomonas aeruginosa-induced biofilm infection is difficult to treat and poses a significant threat to public health. Our previous study found a new coumarin derivative LP4C which exerted potent in vitro and in vivo anti-biofilm activity against Pseudomonas aeruginosa; however, the underlying molecular mechanism and drug-likeness of LP4C is unclear. In this study, we confirmed that LP4C could inhibit the biofilm in dose-dependent manner without bactericidal activity. The transcriptomic profiling and RT-PCR result revealed that bacterial pyrimidine mediated the inhibitory activity of LP4C. The cell viability was not affected in LP4C treatment groups with the concentration under 200 µg/mL, and no death or toxicity sign was observed in mice treated by 20, 40 and 80 mg/kg LP4C during the three-week test period. Ames test presented that LP4C had no effect on the bacterial reverse mutation. In additional, pharmacokinetic results showed that LP4C was likely to have the orally bioavailable properties. Our data indicate that LP4C is a possible lead compound for the development of new anti-biofilm infection agents against Pseudomonas aeruginosa.


Assuntos
Anti-Infecciosos , Infecções por Pseudomonas , Animais , Camundongos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Pseudomonas aeruginosa , Biofilmes , Anti-Infecciosos/farmacologia , Infecções por Pseudomonas/metabolismo , Testes de Sensibilidade Microbiana
13.
J Cell Biochem ; 123(2): 231-247, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34636091

RESUMO

In recent years, long noncoding RNAs (lncRNAs) have been demonstrated to be important tumor-associated regulatory factors. LncRNA growth arrest-specific transcript 5 (Gas5) acts as an anti-oncogene in most cancers. Whether Gas5 acts as an oncogene or anti-oncogene in hepatocellular carcinoma (HCC) remains unclear. In the present study, the expression and role of Gas5 in HCC were investigated in vitro and in vivo. Lower expression levels of Gas5 were determined in HCC tissues and cells by quantitative reverse transcription-polymerase chain reaction. Overexpressed Gas 5 lentiviral vectors were constructed to analyze their influence on cell viability, migration, invasion, and apoptosis. Fluorescence in situ hybridization was used to identify the subcellular localization of Gas5. Protein complexes that bound to Gas5 were isolated from HepG2 cells through pull-down experiments and analyzed by mass spectrometry. A series of novel Gas5-interacting proteins were identified and bioinformatics analysis was carried out. These included ribosomal proteins, proteins involved in protein folding, sorting, and transportation in the ER, some nucleases and protein enzymes involved in gene transcription, translation, and other proteins with various functions.78 kDa glucose-regulated protein (GRP78) was identified as a direct target of Gas5 by Rip-qPCR and Western blot analysis assay. Gas5 inhibited HepG2 cell growth and induced cell apoptosis via upregulating CHOP to activate the ER stress signaling pathway. Further studies indicated that the knockdown of CHOP by shRNA partially reversed Gas5-mediated apoptosis in HepG2 cells. Magnetic resonance imaging showed that the ectopic expression of Gas5 inhibited the growth of HCC in nude mice. These findings suggest that Gas5 functions as a tumor suppressor and induces apoptosis through activation of ER stress by targeting the CHOP signal pathway in HCC.


Assuntos
Apoptose , Estresse do Retículo Endoplasmático , Proteínas de Neoplasias/metabolismo , RNA Longo não Codificante/metabolismo , RNA Neoplásico/metabolismo , Transdução de Sinais , Fator de Transcrição CHOP/metabolismo , Adulto , Idoso , Feminino , Células Hep G2 , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , RNA Longo não Codificante/genética , RNA Neoplásico/genética , Fator de Transcrição CHOP/genética
14.
J Nanobiotechnology ; 20(1): 180, 2022 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-35366899

RESUMO

BACKGROUND: Outbreaks of infection due to multidrug-resistant (MDR) bacteria, especially Gram-negative bacteria, have become a global health issue in both hospitals and communities. Antisense oligonucleotides (ASOs) based therapeutics hold a great promise for treating infections caused by MDR bacteria. However, ASOs therapeutics are strangled because of its low cell penetration efficiency caused by the high molecular weight and hydrophilicity. RESULTS: Here, we designed a series of dendritic poly-peptides (DPP1 to DPP12) to encapsulate ASOs to form DSPE-mPEG2000 decorated ASOs/DPP nanoparticles (DP-AD1 to DP-AD12) and observed that amphipathic DP-AD2, 3, 7 or 8 with a positive charge ≥ 8 showed great efficiency to deliver ASOs into bacteria, but only the two histidine residues contained DP-AD7 and DP-AD8 significantly inhibited the bacterial growth and the targeted gene expression of tested bacteria in vitro. DP-AD7anti-acpP remarkably increased the survival rate of septic mice infected by ESBLs-E. coli, exhibiting strong antibacterial effects in vivo. CONCLUSIONS: For the first time, we designed DPP as a potent carrier to deliver ASOs for combating MDR bacteria and demonstrated the essential features, namely, amphipathicity, 8-10 positive charges, and 2 histidine residues, that are required for efficient DPP based delivery, and provide a novel approach for the development and research of the antisense antibacterial strategy.


Assuntos
Escherichia coli , Oligonucleotídeos Antissenso , Animais , Bactérias , Farmacorresistência Bacteriana Múltipla , Camundongos , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/farmacologia , Peptídeos/farmacologia
15.
J Clin Pharm Ther ; 46(4): 907-917, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33638896

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Edaravone is a new antioxidant and hydroxyl radical scavenger. Although there is evidence that it improves clinical outcomes of patients with acute ischaemic stroke (AIS), it is not yet widely accepted for treatment of AIS in Western countries. We further investigated the efficacy and safety of edaravone through this meta-analysis of randomized controlled clinical trials (RCTs). METHOD: Pubmed, Embase, Web of Science and Cochrane Library were screened up to December 2020 for original articles from SCI journals that published in English. RCTs that compared edaravone versus placebo or no intervention in adult patients and reported the efficacy or safety of edaravone were regarded as eligible. Mortality was regarded as the primary outcome and the improvement of neurological impairment was regarded as the secondary outcome. Safety evaluation was conducted according to the incidence of adverse events. Review Manager 5.3 was employed to perform the assessment of the risk of bias and data synthesis. The Cochrane risk of bias tool for randomized controlled trials was employed to assess the risk of bias. RESULTS AND DISCUSSION: Seven randomized controlled trials with 2069 patients were included. For the incidence of mortality, the pooled RR for studies that evaluated edaravone after three-month follow-up was 0.55 (95% Cl, 0.43-0.7, I2  = 0, P < 0.01). The pooled RR for improvement of neurological impairment at the three months follow-up was 1.54 (95% CI, 1.27-1.87, I2  = 0, P < 0.01) in four RCTs. On subgroup analysis of studies that were conducted in Asia, the RR was 1.56 (95% CI, 1.27-1.90, I2  = 0%; P < 0.01); the pooled RR for studies that conducted in Europe was 1.32 (95% CI, 0.64-2.72; P = 0.45); the pooled RR for studies that used edaravone for two weeks was 1.42 (95% CI, 1.10 to 1.83, I2  = 0%; P < 0.01); the pooled RR for studies that used edaravone for one week was 1.64 (95% CI, 1.24-2.16, I2  = 0%; P < 0.01); the pooled RR for studies that conducted in patients with mean age equal to or over 60 years was 1.52 (95% CI, 1.24-1.87, I2  = 0%; P < 0.01); and the pooled RR for studies that conducted in patients with mean age less than 60 was 1.80 (95% CI, 1.05-3.08, I2  = 0%; P = 0.03). For the incidence of any treatment-related adverse events, the pooled RR for studies that evaluated edaravone during treatment was 0.83 (95% CI, 0.51-1.34, I2  = 0, P = 0.43). The difference of the incidence of any treatment-related adverse events between two groups was not statistically significant. WHAT IS NEW AND CONCLUSION: The limited studies indicate that edaravone can improve neurological impairment with a survival benefit at three-month follow-up, regardless of the mean age and course of treatment. It is worthy of promotion in the clinical treatment of AIS in Asian countries. More well-designed RCTs with larger sample sizes are needed to determine the benefits of edaravone in patients from Western countries.


Assuntos
Edaravone/uso terapêutico , AVC Isquêmico/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Fatores Etários , Edaravone/administração & dosagem , Edaravone/efeitos adversos , Humanos , AVC Isquêmico/mortalidade , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
Biochem Biophys Res Commun ; 523(4): 939-946, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-31964533

RESUMO

Proadrenomedullin N-terminal 20 peptide (PAMP) is elevated in sepsis, but the function and possible mechanism of PAMP in bacterial infection is elusive. This study is aim to evaluate the role of PAMP in the interaction between the Enterohemorrhagic E. coli (EHEC) and the host barrier. Our results showed that PAMP alleviated the EHEC-induced disruption of goblet cells and mucosal damage in the intestine, increased the expression of occludin in the colon of EHEC-infected mice, and reduced the proinflammatory cytokines level in serum significantly compared with the control group. Meanwhile, lipopolysaccharide (LPS) stimulation could dose-dependently induce the expression of preproADM, the precursor of PAMP, in human intestinal epithelial cell (HIEC) and human umbilical vein endothelial cell (HUVEC). In addition, PAMP inhibited the growth of EHEC O157:H7 and destroyed the inner and outer membrane. At low concentration, PAMP attenuated the EHEC virulence genes including hlyA and eaeA, which was also confirmed from reduced hemolysis to red cells and adhesion to HIEC. These results indicated that EHEC infection would modulate the expression of PAMP in intestinal epithelium or vascular endothelium, and in turn exerted a protective effect in EHEC induced infection by rupturing the bacterial cell membrane and attenuating the bacterial virulence.


Assuntos
Adrenomedulina/uso terapêutico , Membrana Celular/metabolismo , Escherichia coli Êntero-Hemorrágica/fisiologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Inflamação/microbiologia , Intestinos/microbiologia , Substâncias Protetoras/farmacologia , Adrenomedulina/química , Adrenomedulina/farmacologia , Sequência de Aminoácidos , Animais , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Membrana Celular/efeitos dos fármacos , Citocinas/metabolismo , Escherichia coli Êntero-Hemorrágica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Virulência/genética
17.
J Biomed Sci ; 27(1): 26, 2020 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-31954394

RESUMO

Acinetobacter baumannii (A. baumannii) is an important opportunistic pathogen causing serious nosocomial infections, which is considered as the most threatening Gram-negative bacteria (GNB). Outer membrane protein A (OmpA), a major component of outer membrane proteins (OMPs) in GNB, is a key virulence factor which mediates bacterial biofilm formation, eukaryotic cell infection, antibiotic resistance and immunomodulation. The characteristics of OmpA in Escherichia coli (E. coli) have been extensively studied since 1974, but only in recent years researchers started to clarify the functions of OmpA in A. baumannii. In this review, we summarized the structure and functions of OmpA in A. baumannii (AbOmpA), collected novel therapeutic strategies against it for treating A. baumannii infection, and emphasized the feasibility of using AbOmpA as a potential therapeutic target.


Assuntos
Infecções por Acinetobacter/terapia , Acinetobacter baumannii/fisiologia , Proteínas da Membrana Bacteriana Externa/genética , Acinetobacter baumannii/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Humanos
18.
Phys Chem Chem Phys ; 22(20): 11609-11613, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32401246

RESUMO

Through combining a four-point probe and an optical technique, a profound vanadium(v) size effect on the change in excess resistivity during hydrogenation is observed in Fen/V7n (n = 2, 4) superlattices at c ≥ 0.05 H/V. This phenomenon highly emphasizes the effect of interface and H-H interaction on the electrical properties of hydrogen in these systems.

19.
J Nanobiotechnology ; 18(1): 109, 2020 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753061

RESUMO

BACKGROUND: Antisense oligonucleotides (ASOs) based technology is considered a potential strategy against antibiotic-resistant bacteria; however, a major obstacle to the application of ASOs is how to deliver them into bacteria effectively. DNA tetrahedra (Td) is an emerging carrier for delivering ASOs into eukaryotes, but there is limited information about Td used for bacteria. In this research, we investigated the uptake features of Td and the impact of linkage modes between ASOs and Td on gene-inhibition efficiency in bacteria. RESULTS: Td was more likely to adhere to bacterial membranes, with moderate ability to penetrate into the bacteria. Strikingly, Td could penetrate into bacteria more effectively with the help of Lipofectamine 2000 (LP2000) at a 0.125 µL/µg ratio to Td, but the same concentration of LP2000 had no apparent effect on linear DNA. Furthermore, linkage modes between ASOs and Td influenced gene-knockdown efficiency. Looped structure of ASOs linked to one side of the Td exhibited better gene-knockdown efficiency than the overhung structure. CONCLUSIONS: This study established an effective antisense delivery system based on loop-armed Td, which opens opportunities for developing antisense antibiotics.


Assuntos
Antibacterianos , DNA , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Oligonucleotídeos Antissenso , Antibacterianos/química , Antibacterianos/farmacocinética , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , DNA/química , DNA/farmacocinética , Técnicas de Silenciamento de Genes , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Lipídeos , Oligonucleotídeos Antissenso/química , Oligonucleotídeos Antissenso/farmacocinética
20.
Molecules ; 24(11)2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31159358

RESUMO

The DNA tetrahedron (Td), as one of the novel DNA-based nanoscale biomaterials, has been extensively studied because of its excellent biocompatibility and increased possibilities for decorating precisely. Although the use of Td in laboratories is well established, knowledge surrounding the factors influencing its preparation and storage is lacking. In this research, we investigated the role of the magnesium ions, which greatly affect the structure and stability of DNA. We assembled 1, 2, 5, 10 and 20 µM Td in buffers containing different Mg2+ concentrations, demonstrating that 2 and 5 mM Mg2+ is optimal in these conditions, and that yields decrease dramatically once the DNA concentration reaches 20 µM or the Mg2+ concentration is lower than 0.5 mM. We also verified that the Td structure is retained better through freeze-thawing than lyophilization. Furthermore, a lower initial Mg2+ (≤2 mM) benefited the maintenance of Td structure in the process of lyophilization. Hence, our research sheds light on the influence of Mg2+ in the process of preparing and storing Td, and also provides some enlightenment on improving yields of other DNA nanostructures.


Assuntos
DNA/química , Íons/química , Magnésio/química , Liofilização , Microscopia de Força Atômica , Nanopartículas/química , Nanoestruturas/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA