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1.
Cell Biochem Funct ; 42(4): e4059, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38773900

RESUMO

Cerebral ischemic stroke remains a leading cause of mortality and morbidity worldwide. Toll-like receptor 4 (TLR4) has been implicated in neuroinflammatory responses poststroke, particularly in the infiltration of immune cells and polarization of macrophages. This study aimed to elucidate the impact of TLR4 deficiency on neutrophil infiltration and subsequent macrophage polarization after middle cerebral artery occlusion (MCAO), exploring its role in stroke prognosis. The objective was to investigate how TLR4 deficiency influences neutrophil behavior poststroke, its role in macrophage polarization, and its impact on stroke prognosis using murine models. Wild-type and TLR4-deficient adult male mice underwent MCAO induction, followed by various analyses, including flow cytometry to assess immune cell populations, bone marrow transplantation experiments to evaluate TLR4-deficient neutrophil behaviors, and enzyme-linked immunosorbent assay and Western blot analysis for cytokine and protein expression profiling. Neurobehavioral tests and infarct volume analysis were performed to assess the functional and anatomical prognosis poststroke. TLR4-deficient mice exhibited reduced infarct volumes, increased neutrophil infiltration, and reduced M1-type macrophage polarization post-MCAO compared to wild-type mice. Moreover, the depletion of neutrophils reversed the neuroprotective effects observed in TLR4-deficient mice, suggesting the involvement of neutrophils in mediating TLR4's protective role. Additionally, N1-type neutrophils were found to promote M1 macrophage polarization via neutrophil gelatinase-associated lipocalin (NGAL) secretion, a process blocked by TLR4 deficiency. The study underscores the protective role of TLR4 deficiency in ischemic stroke, delineating its association with increased N2-type neutrophil infiltration, diminished M1 macrophage polarization, and reduced neuroinflammatory responses. Understanding the interplay between TLR4, neutrophils, and macrophages sheds light on potential therapeutic targets for stroke management, highlighting TLR4 as a promising avenue for intervention in stroke-associated neuroinflammation and tissue damage.


Assuntos
Macrófagos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos , Receptor 4 Toll-Like , Animais , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/deficiência , Camundongos , Masculino , Macrófagos/metabolismo , Macrófagos/imunologia , Prognóstico , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Neutrófilos/metabolismo , Neutrófilos/imunologia
2.
J Agric Food Chem ; 72(8): 4127-4141, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38362879

RESUMO

An amyloid-ß (Aß) fibril is a vital pathogenic factor of Alzheimer's disease (AD). Aß fibril disintegrators possess great potential to be developed into novel anti-AD agents. Here, a ligand fishing method was employed to rapidly discover Aß42 fibril disintegrators from Ganoderma lucidum using Aß42 fibril-immobilized magnetic beads, which led to the isolation of six Aß42 fibril disintegrators including ganodermanontriol, ganoderic acid DM, ganoderiol F, ganoderol B, ganodermenonol, and ergosterol. Neuroprotective evaluation in vitro exhibited that these Aß42 fibril disintegrators could significantly mitigate Aß42-induced neurotoxicity. Among these six disintegrators, ergosterol and ganoderic acid DM with stronger protecting activity were further selected to evaluate their neuroprotective effect on AD in vivo. Results showed that ergosterol and ganoderic acid DM could significantly alleviate Aß42-induced cognitive dysfunction and hippocampus neuron loss in vivo. Moreover, ergosterol and ganoderic acid DM could significantly inhibit Aß42-induced neuron apoptosis and Nrf2-mediated neuron oxidative stress in vitro and in vivo.


Assuntos
Doença de Alzheimer , Fármacos Neuroprotetores , Reishi , Triterpenos , Doença de Alzheimer/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Ligantes , Peptídeos beta-Amiloides , Amiloide , Ergosterol , Fragmentos de Peptídeos/uso terapêutico
3.
Nat Commun ; 14(1): 6912, 2023 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-37903783

RESUMO

Radiation triage and biological dosimetry are critical for the medical management of massive potentially exposed individuals following radiological accidents. Here, we performed a genome-wide screening of radiation-responding mRNAs, whose N6-methyladenosine (m6A) levels showed significant alteration after acute irradiation. The m6A levels of three genes, Ncoa4, Ate1 and Fgf22, in peripheral blood mononuclear cells (PBMCs) of mice showed excellent dose-response relationships and could serve as biomarkers of radiation exposure. Especially, the RNA m6A of Ncoa4 maintained a high level as long as 28 days after irradiation. We demonstrated its responsive specificity to radiation, conservation across the mice, monkeys and humans, and the dose-response relationship in PBMCs from cancer patients receiving radiation therapy. Finally, NOCA4 m6A-based biodosimetric models were constructed for estimating absorbed radiation doses in mice or humans. Collectively, this study demonstrated the potential feasibility of RNA m6A in radiation accidents management and clinical applications.


Assuntos
Leucócitos Mononucleares , RNA , Humanos , Animais , Camundongos , Relação Dose-Resposta à Radiação , Biomarcadores , Radiação Ionizante
4.
Plant Cell ; 36(1): 136-157, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37823521

RESUMO

Acetylation is an important posttranslational modification (PTM) that regulates almost all core processes of autophagy in yeast and mammals. However, the role of protein acetylation in plant autophagy and the underlying regulatory mechanisms remain unclear. Here, we show the essential role of the putative acetyltransferase HOOKLESS1 (HLS1) in acetylation of the autophagy-related protein ATG18a, a key autophagy component that regulates autophagosome formation in Arabidopsis (Arabidopsis thaliana). Loss of HLS1 function suppressed starvation-induced autophagy and increased plant susceptibility to nutrient deprivation. We discovered that HLS1 physically interacts with and directly acetylates ATG18a both in vitro and in vivo. In contrast, mutating putative active sites in HLS1 inhibited ATG18a acetylation and suppressed autophagy upon nutrient deprivation. Accordingly, overexpression of ATG18a mutant variants with lower acetylation levels inhibited the binding activity of ATG18a to PtdIns(3)P and autophagosome formation under starvation conditions. Moreover, HLS1-modulated autophagy was uncoupled from its function in hook development. Taken together, these findings shed light on a key regulator of autophagy and further elucidate the importance of PTMs in modulating autophagy in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Processamento de Proteína Pós-Traducional , Nutrientes , Autofagia/genética
5.
Front Immunol ; 14: 1188308, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37545497

RESUMO

Objective: This study was aimed to evaluate the efficacy and safety of transarterial chemoembolization combined with tyrosine kinase inhibitors and camrelizumab in the treatment of unresectable hepatocellular carcinoma and to explore a new therapeutic strategy for the treatment of advanced HCC. Patients and methods: A total of 87 patients aged 18-75 years with at least one measurable lesion per Response Evaluation Criteria in Solid Tumors (version 1.1) were included in the study. TACE was administered as needed, and camrelizumab and TKI medication were initiated within two weeks and one week after TACE, respectively. The primary endpoints were progression-free survival and objective response rate. Results: The 87 patients in this trial were last evaluated on September 28, 2022, and 35.8% were still receiving treatment at the data cutoff. A total of 34 patients (39.1%) died, and the median OS was not reached. The median PFS was 10.5 months (95% CI: 7.8-13.1). The ORR rate was 71.3% (62/87), and the DCR rate was 89.7% (78/87) per mRECIST. According to RECIST version 1.1, the ORR rate was 35.6% (31/87), and the DCR rate was 87.4% (76/87). Ten patients (11.5%) successfully underwent conversion therapy and all achieved R0 resection. Two patients achieved a complete pathological response, four achieved a major pathological response, and four had a partial response. All treatment-related adverse events were tolerated. No serious adverse events were observed, and no treatment-related deaths occurred. Conclusions: TACE combined with TKI and camrelizumab was safe and effective in treating advanced HCC. Triple therapy may benefit patients with large tumor burden and portal vein cancer thrombus and is expected to provide a new treatment strategy for advanced HCC. Clinical Trial Registration: ClinicalTrials.gov, identifier ChiCTR2000039508.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/efeitos adversos , Neoplasias Hepáticas/terapia
7.
Plant J ; 115(6): 1514-1527, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37269223

RESUMO

The signaling pathways for the phytohormones ethylene and abscisic acid (ABA) have antagonistic effects on seed germination and early seedling establishment. However, the underlying molecular mechanisms remain unclear. In Arabidopsis thaliana, ETHYLENE INSENSITIVE 2 (EIN2) localizes to the endoplasmic reticulum (ER); although its biochemical function is unknown, it connects the ethylene signal with the key transcription factors EIN3 and EIN3-LIKE 1 (EIL1), leading to the transcriptional activation of ethylene-responsive genes. In this study, we uncovered an EIN3/EIL1-independent role for EIN2 in regulating the ABA response. Epistasis analysis demonstrated that this distinct role of EIN2 in the ABA response depends on HOOKLESS 1 (HLS1), the putative histone acetyltransferase acting as a positive regulator of ABA responses. Protein interaction assays supported a direct physical interaction between EIN2 and HLS1 in vitro and in vivo. Loss of EIN2 function resulted in an alteration of HLS1-mediated histone acetylation at the ABA-INSENSITIVE 3 (ABI3) and ABI5 loci, which promotes gene expression and the ABA response during seed germination and early seedling growth, indicating that the EIN2-HLS1 module contributes to ABA responses. Our study thus revealed that EIN2 modulates ABA responses by repressing HLS1 function, independently of the canonical ethylene pathway. These findings shed light on the intricate regulatory mechanisms underling the antagonistic interactions between ethylene and ABA signaling, with significant implications for our understanding of plant growth and development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Ácido Abscísico/metabolismo , Plântula/metabolismo , Germinação , Proteínas de Arabidopsis/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Sementes/genética , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo
8.
Exp Cell Res ; 429(2): 113629, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37187249

RESUMO

Colorectal cancer (CRC) is a highly invasive malignant tumor with pronounced proliferation capacity and is prone to epithelial-mesenchymal transition (EMT) and subsequent metastasis. A disintegrin and metalloproteinase domain-like decysin 1 (ADAMDEC1) is a proteolytically active metzincin metalloprotease that is involved in extracellular matrix remodeling, cell adhesion, invasion, and migration. However, the effects of ADAMDEC1 on CRC are unclear. This study was conducted to investigate the expression and biological role of ADAMDEC1 in CRC. We found that ADAMDEC1 was differentially expressed in CRC. Further, ADAMDEC1 was found to enhance CRC proliferation, migration, and invasion while inhibiting apoptosis. Exogenous ADAMDEC1 overexpression elicited EMT in CRC cells, as evidenced by alterations in E-cadherin, N-cadherin, and vimentin expression. In ADAMDEC1 knockdown or ADAMDEC1 overexpressed CRC cells, the western blotting analysis revealed that Wnt/ß-catenin signaling pathway-related proteins were down-regulated or up-regulated. Furthermore, an inhibitor of the Wnt/ß-catenin pathway (FH535) partially negated the effect of ADAMDEC1 overexpression on EMT and CRC cell proliferation. Further mechanistic research suggested that ADAMDEC1 knockdown may upregulate GSK-3ß and inactivate the Wnt/ß-catenin pathway, accompanied by suppressing the expression of ß-catenin. Additionally, the blocker of GSK-3ß (CHIR-99021) markedly abolished the inhibitory effect of ADAMDEC1 knockdown on Wnt/ß-catenin signaling. Our results indicate that ADAMDEC1 promotes CRC metastasis by negatively regulating GSK-3ß, activating the Wnt/ß-catenin signaling pathway, and inducing EMT, presenting its potential as a therapeutic target for the treatment of metastatic CRC.


Assuntos
Neoplasias Colorretais , Via de Sinalização Wnt , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/genética , Glicogênio Sintase Quinase 3 beta/metabolismo
9.
J Integr Plant Biol ; 65(7): 1703-1716, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36939002

RESUMO

Plants have adopted versatile scaffold proteins to facilitate the crosstalk between multiple signaling pathways. Leaf senescence is a well-programmed developmental stage that is coordinated by various external and internal signals. However, the functions of plant scaffold proteins in response to senescence signals are not well understood. Here, we report that the scaffold protein RACK1A (RECEPTOR FOR ACTIVATED C KINASE 1A) participates in leaf senescence mediated by ethylene signaling via the coordination of the EIN3-miR164-ORE1 transcriptional regulatory cascade. RACK1A is a novel positive regulator of ethylene-mediated leaf senescence. The rack1a mutant exhibits delayed leaf senescence, while transgenic lines overexpressing RACK1A display early leaf senescence. Moreover, RACK1A promotes EIN3 (ETHYLENE INSENSITIVE 3) protein accumulation, and directly interacts with EIN3 to enhance its DNA-binding activity. Together, they then associate with the miR164 promoter to inhibit its transcription, leading to the release of the inhibition on downstream ORE1 (ORESARA 1) transcription and the promotion of leaf senescence. This study reveals a mechanistic framework by which RACK1A promotes leaf senescence via the EIN3-miR164-ORE1 transcriptional cascade, and provides a paradigm for how scaffold proteins finely tune phytohormone signaling to control plant development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Receptores de Quinase C Ativada , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Senescência Vegetal , Receptores de Quinase C Ativada/genética , Receptores de Quinase C Ativada/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
Front Psychol ; 13: 962403, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36524172

RESUMO

Abusive supervision could negatively influence individual work attitudes, behaviors, and work outcomes. Self-efficacy and work engagement can help to increase nursing performance. But few studies have attempted to determine the specific mechanism between them in China. The objective is to analyze the levels of abusive supervision, self-efficacy, and work engagement, and to explore the relationship between these three variables among Chinese clinical registered nurses. A predictive, cross-sectional quantitative survey was performed in a convenience sample of 923 Chinese clinical nurses. The instruments included the Demographic Data Questionnaire, Abusive Supervision Scale, Self-efficacy Scale and Work Engagement Scale. A total of 702 valid questionnaires were returned, yielding a favorable response rate of 76.1%. The level of abusive supervision was at the mid-low level, with a mean of 1.55. The nurses presented a relative high level of self-efficacy (M = 4.97) and work engagement (M = 5.01). A statistically significant negative correlation between abusive supervision and self-efficacy (r = -0.21, p < 0.01). A statistically significant negative correlation between abusive supervision and work engagement (r = -0.32, p < 0.01), and a statistically significant positive correlation between self-efficacy and work engagement (r = 0.43, p < 0.01). Abusive supervision had a directly negative effect on self-efficacy (ß = -0.23, p < 0.01) and work engagement (ß = -0.24, p < 0.01). Self-efficacy positively predicted work engagement (ß = 0.41, p < 0.01). The results indicated that abusive supervision could negatively predict nurses' work engagement directly and that abusive supervision could also indirectly influence work engagement partly through the mediation of self-efficacy. Nursing managers should take effective measures to prevent and control the abusive management and leadership behavior of head nurses, and improve nurses' self-efficacy, so that nurses can experience full respect, support, and self-confidence. They can devote themselves to work with the greatest enthusiasm.

11.
Front Neurorobot ; 16: 914705, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35859657

RESUMO

The entity relation extraction in the form of triples from unstructured text is a key step for self-learning knowledge graph construction. Two main methods have been proposed to extract relation triples, namely, the pipeline method and the joint learning approach. However, these models do not deal with the overlapping relation problem well. To overcome this challenge, we present a relation-oriented model with global context information for joint entity relation extraction, namely, ROMGCJE, which is an encoder-decoder model. The encoder layer aims to build long-term dependencies among words and capture rich global context representation. Besides, the relation-aware attention mechanism is applied to make use of the relation information to guide the entity detection. The decoder part consists of a multi-relation classifier for the relation classification task, and an improved long short-term memory for the entity recognition task. Finally, the minimum risk training mechanism is introduced to jointly train the model to generate final relation triples. Comprehensive experiments conducted on two public datasets, NYT and WebNLG, show that our model can effectively extract overlapping relation triples and outperforms the current state-of-the-art methods.

12.
Appl Microbiol Biotechnol ; 106(1): 211-226, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34889983

RESUMO

The rising prevalence of antibiotic resistance poses the greatest health threats. Antimicrobial peptides (AMPs) are regarded as the potentially effective therapy. To avoid current crisis of antibiotic resistance, a comprehensive understanding of AMP resistance is necessary before clinical application. In this study, the development of resistance to the anti-Gram-negative bacteria peptide N6NH2 (21 residues, ß-sheet) was characterized in E. coli ATCC25922. Three N6NH2-resistant E. coli mutants with 32-fold increase in MIC were isolated by serially passaging bacterial lineages in progressively increasing concentrations of N6NH2 and we mainly focus on the phenotype of N6NH2-resistant bacteria different from sensitive bacteria. The results showed that the resistance mechanism was attributed to synergy effect of multiple mechanisms: (i) increase biofilm formation capacity (3 ~ 4-fold); (ii) weaken the affinity of lipopolysaccharide (LPS) with N6NH2 (3 ~ 8-fold); and (iii) change the cell membrane permeability and potential. Interestingly, a chimeric peptide-G6, also a N6NH2 analog, which keep the same antibacterial activity to both wild-type and resistant clones (MIC value: 16 µg/mL), could curb N6NH2-resistant mutants by stronger inhibition of biofilm formation, stronger affinity with LPS, and stronger membrane permeability and depolarization than that of N6NH2.


Assuntos
Infecções por Escherichia coli , Escherichia coli , Antibacterianos/farmacologia , Peptídeos Antimicrobianos , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana
13.
Front Microbiol ; 12: 637427, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33767681

RESUMO

Edwardsiella tarda is a facultative intracellular pathogen in humans and animals. There is no effective way except vaccine candidates to eradicate intracellular E. tarda. In this study, four derivatives of marine peptide-N6NH2 were designed by an introduction of unnatural residues or substitution of natural ones, and their intracellular activities against E. tarda were evaluated in macrophages and in mice, respectively. The minimum inhibitory concentration (MIC) value of N6NH2 and GUON6NH2 against E. tarda was 8 µg/mL. GUON6NH2 showed higher stability to trypsin, lower toxicity (<1%) and longer post-antibiotic effect (PAE) than N6NH2 and other derivatives. Antibacterial mechanism results showed that GUON6NH2 could bind to LPS and destroyed outer/inner cell membranes of E. tarda, superior to N6NH2 and norfloxacin. Both N6NH2 and GUON6NH2 were internalized into macrophages mainly via lipid rafts, micropinocytosis, and microtubule polymerization, respectively, and distributed in the cytoplasm. The intracellular inhibition rate of GUON6NH2 against E. tarda was 97.05-100%, higher than that in case of N6NH2 (96.82-100%). In the E. tarda-induced peritonitis mouse model, after treatment with of 1 µmol/kg N6NH2 and GUON6NH2, intracellular bacterial numbers were reduced by 1.54- and 1.97-Log10 CFU, respectively, higher than norfloxacin (0.35-Log10 CFU). These results suggest that GUON6NH2 may be an excellent candidate for novel antimicrobial agents to treat infectious diseases caused by intracellular E. tarda.

14.
Biomed Res Int ; 2021: 6666453, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688501

RESUMO

BACKGROUND: A prediction model can be developed to predict the risk of cancer-related cognitive impairment in colorectal cancer patients after chemotherapy. METHODS: A regression analysis was performed on 386 colorectal cancer patients who had undergone chemotherapy. Three prediction models (random forest, logistic regression, and support vector machine models) were constructed using collected clinical and pathological data of the patients. Calibration and ROC curves and C-indexes were used to evaluate the selected models. A decision curve analysis (DCA) was used to determine the clinical utility of the line graph. RESULTS: Three prediction models including a random forest, a logistic regression, and a support vector machine were constructed. The logistic regression model had the strongest predictive power with an area under the curve (AUC) of 0.799. Age, BMI, colostomy, complications, CRA, depression, diabetes, QLQ-C30 score, exercise, hypercholesterolemia, diet, marital status, education level, and pathological stage were included in the nomogram. The C-index (0.826) and calibration curve showed that the nomogram had good predictive ability and the DCA curves indicated that the model had strong clinical utility. CONCLUSIONS: A prediction model with good predictive ability and practical clinical value can be developed for predicting the risk of cognitive impairment in colorectal cancer after chemotherapy.


Assuntos
Disfunção Cognitiva , Neoplasias Colorretais , Modelos Biológicos , Idoso , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/epidemiologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nomogramas , Valor Preditivo dos Testes
15.
Appl Microbiol Biotechnol ; 105(6): 2351-2361, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33635357

RESUMO

Aeromonas veronii can cause a variety of diseases such as sepsis in humans and animals. However, there has been no effective way to eradicate A. veronii. In this study, the intracellular antibacterial activities of the C-terminal aminated marine peptide N6 (N6NH2) and its D-enantiomer (DN6NH2) against A. veronii were investigated in macrophages and in mice, respectively. The result showed that DN6NH2 with the minimum inhibitory concentration (MIC) of 1.62 µM is more resistant to cathepsin B than N6NH2 (3.23 µM). The penetration percentages of the cells treated with 4-200 µg/mL fluorescein isothiocyanate (FITC)-DN6NH2 were 52.5-99.6%, higher than those of FITC-N6NH2 (27.0-99.1%). Both N6NH2 and DN6NH2 entered macrophages by macropinocytosis and an energy-dependent manner. DN6NH2 reduced intracellular A. veronii by 34.57%, superior to N6NH2 (19.52%). After treatment with 100 µg/mL DN6NH2, the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1ß were reduced by 53.45%, 58.54%, and 44.62%, respectively, lower than those of N6NH2 (15.65%, 12.88%, and 14.10%, respectively); DN6NH2 increased the IL-10 level (42.94%), higher than N6NH2 (7.67%). In the mice peritonitis model, 5 µmol/kg DN6NH2 reduced intracellular A. veronii colonization by 73.22%, which was superior to N6NH2 (32.45%) or ciprofloxacin (45.67%). This suggests that DN6NH2 may be used as the candidate for treating intracellular multidrug-resistant (MDR) A. veronii. KEY POINTS: • DN6NH2 improved intracellular antibacterial activity against MDR A. veronii. • DN6NH2 entered macrophages by micropinocytosis and enhanced the internalization rates. • DN6NH2 effectively protected the mice from infection with A. veronii.


Assuntos
Aeromonas , Infecções por Bactérias Gram-Negativas , Peritonite , Aeromonas veronii , Animais , Antibacterianos/farmacologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Camundongos , Testes de Sensibilidade Microbiana , Peritonite/tratamento farmacológico
16.
FEBS J ; 288(4): 1091-1106, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32681661

RESUMO

In recent years, the rise of antibiotic resistance has become a primary health problem. With the emergence of bacterial resistance, the need to explore and develop novel antibacterial drugs has become increasingly urgent. Filamentous temperature-sensitive mutant Z (FtsZ), a crucial cell division protein of bacteria, has become a vital antibacterial target. FtsZ is a filamentous GTPase; it is highly conserved in bacteria and shares less than 20% sequence identity with the eukaryotic cytoskeleton protein tubulin, indicating that FtsZ-targeting antibacterial agents may have a low cytotoxicity toward eukaryotes. FtsZ can form a dynamic Z-ring in the center of the cell resulting in cell division. Furthermore, disturbance in the assembly of FtsZ may affect cellular dynamics and bacterial cell survival, making it a fascinating target for drug development. This review focuses on the recent discovery of FtsZ inhibitors, including peptides, natural products, and other synthetic small molecules, as well as their mechanism of action, which could facilitate the discovery of novel FtsZ-targeting clinical drugs in the future.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/prevenção & controle , Proteínas de Bactérias/antagonistas & inibidores , Proteínas do Citoesqueleto/antagonistas & inibidores , Peptídeos/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Bactérias/metabolismo , Bactérias/patogenicidade , Infecções Bacterianas/microbiologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/metabolismo , Humanos , Modelos Moleculares , Estrutura Molecular , Peptídeos/química , Peptídeos/metabolismo , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Virulência/efeitos dos fármacos
17.
Mar Drugs ; 18(12)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348729

RESUMO

Edwardsiella tarda can cause fatal gastro-/extraintestinal diseases in fish and humans. Overuse of antibiotics has led to antibiotic resistance and contamination in the environment, which highlights the need to find new antimicrobial agents. In this study, the marine peptide-N6 was amidated at its C-terminus to generate N6NH2. The antibacterial activity of N6 and N6NH2 against E. tarda was evaluated in vitro and in vivo; their stability, toxicity and mode of action were also determined. Minimal inhibitory concentrations (MICs) of N6 and N6NH2 against E. tarda were 1.29-3.2 µM. Both N6 and N6NH2 killed bacteria by destroying the cell membrane of E. tarda and binding to lipopolysaccharide (LPS) and genomic DNA. In contrast with N6, N6NH2 improved the stability toward trypsin, reduced hemolysis (by 0.19% at a concentration of 256 µg/mL) and enhanced the ability to penetrate the bacterial outer and inner membrane. In the model of fish peritonitis caused by E. tarda, superior to norfloxacin, N6NH2 improved the survival rate of fish, reduced the bacterial load on the organs, alleviated the organ injury and regulated the immunity of the liver and kidney. These data suggest that the marine peptide N6NH2 may be a candidate for novel antimicrobial agents against E. tarda infections.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Edwardsiella tarda/efeitos dos fármacos , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/virologia , Doenças dos Peixes/tratamento farmacológico , Animais , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Membrana Celular/efeitos dos fármacos , Infecções por Enterobacteriaceae/microbiologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/patologia , Proteínas de Peixes , Rim/patologia , Fígado/patologia , Testes de Sensibilidade Microbiana , Norfloxacino/uso terapêutico , Peritonite/tratamento farmacológico , Peritonite/etiologia , Relação Estrutura-Atividade , Análise de Sobrevida
18.
Int J Mol Sci ; 21(24)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348848

RESUMO

Aeromonas veronii is one of the main pathogens causing various diseases in humans and animals. It is currently difficult to eradicate drug-resistant A. veronii due to the biofilm formation by conventional antibiotic treatments. In this study, a marine peptide-N6NH2 and its analogs were generated by introducing Orn or replacing with D-amino acids, Val and Pro; their enzymic stability and antibacterial/antibiofilm ability against multi-drug resistant (MDR) A. veronii ACCC61732 were detected in vitro and in vivo, respectively. The results showed that DN6NH2 more rapidly killed A. veronii ACCC61732 and had higher stability in trypsin, simulated gastric/intestinal fluid, proteinase K, and mouse serum than the parent peptide-N6NH2. DN6NH2 and other analogs significantly improved the ability of N6NH2 to penetrate the outer membrane of A. veronii ACCC61732. DN6NH2, N6PNH2 and V112N6NH2 protected mice from catheter-associated biofilm infection with MDR A. veronii ACCC61732, superior to N6NH2 and CIP. DN6NH2 had more potent efficacy at a dose of 5 µmol/kg (100% survival) in a mouse peritonitis model than other analogs (50-66.67%) and CIP (83.33%), and it inhibited the bacterial translocation, downregulated pro-inflammatory cytokines, upregulated the anti-inflammatory cytokine, and ameliorated multiple-organ injuries (including the liver, spleen, lung, and kidney). These data suggest that the analogs of N6NH2 may be a candidate for novel antimicrobial and antibiofilm agents against MDR A. veronii infections.


Assuntos
Aeromonas veronii/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Insuficiência de Múltiplos Órgãos/tratamento farmacológico , Úlcera Cutânea/tratamento farmacológico , Aeromonas veronii/crescimento & desenvolvimento , Animais , Biofilmes/efeitos dos fármacos , Feminino , Infecções por Bactérias Gram-Negativas/complicações , Infecções por Bactérias Gram-Negativas/microbiologia , Camundongos , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Insuficiência de Múltiplos Órgãos/complicações , Insuficiência de Múltiplos Órgãos/microbiologia , Úlcera Cutânea/complicações , Úlcera Cutânea/microbiologia
19.
Front Immunol ; 9: 2231, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30364107

RESUMO

IgE is the key mediator of allergic responses. Omalizumab, an IgE-specific monoclonal antibody that depletes IgE, is effective for treating severe allergic asthma. The need for frequent administration of the expensive drug, however, limits its applications. Taking advantage of T cell memory, adoptive T cell therapy (ACT) targeting IgE-producing cells has the potential to achieve long-term suppression of IgE and relief of symptoms for severe allergic diseases. The transmembrane form of IgE (mIgE), which is present on all IgE-producing cells, serves as an excellent molecular target for ACT that employs chimeric antigen receptors (CARs). Here, we designed and tested CARs that use the extracellular domain of high affinity IgE receptor, FcεRIα, for mIgE recognition. When expressed on Jurkat T cells, FcεRIα-based CARs mediated robust responses in terms of CD69 upregulation to U266 myeloma cells expressing low levels of mIgE. FcεRIα-based CARs specifically recognized cells expressing mIgE, but not cells with secreted IgE captured through Fcε receptors. CAR+ Jurkat cells did not respond to LAD2 mast cells with secreted IgE bound through FcεRI or Ramos cells with secreted IgE bound through FcεRII. Co-culture of CAR+ Jurkat cells and LAD2 mast cells with IgE bound did not trigger LAD2 cell degranulation. The activity of CAR using wild type FcεRIα for mIgE binding was inhibited by the presence secreted IgE, which likely blocked CAR-mIgE interaction. The activities of CARs using low affinity mutants of FcεRIα, however, tolerated secreted IgE at relatively high concentrations. Moreover, primary human CD8+ T cells expressing a low affinity mutant CAR responded to U266 cells with INFγ production and cytotoxicity despite the presence of secreted IgE. The potency, specificity, and robustness of our CAR design, combined with repaid advances in the safety of ACT, hold promise for novel and highly effective cell-based therapies against severe allergic diseases.


Assuntos
Imunoglobulina E/imunologia , Receptores de Antígenos Quiméricos/imunologia , Receptores de IgE/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Afinidade de Anticorpos/imunologia , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Asma/imunologia , Asma/terapia , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Imunoglobulina E/genética , Imunoglobulina E/metabolismo , Imunoterapia Adotiva/métodos , Células Jurkat , Mutação , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Receptores de IgE/genética , Receptores de IgE/metabolismo , Especificidade do Receptor de Antígeno de Linfócitos T/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo
20.
J Environ Sci (China) ; 65: 335-346, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29548405

RESUMO

Disinfection byproduct (DBP) precursors in wastewater during the reversed anaerobic-anoxic-oxic (A2/O) process, as well as their molecular weight (MW) and polarity-based fractions, were characterized with UV scanning, fluorescence excitation emission matrix, Fourier transform infrared and nuclear magnetic resonance spectroscopy. Their DBP formation potentials (DBPFPs) after chlorination were further tested. Results indicated that the reversed A2/O process could not only effectively remove the dissolved organic carbon (DOC) and dissolved total nitrogen in the wastewater, but also affect the MW distribution and hydrophilic-hydrophobic properties of dissolved organic matter (DOM). The accumulation of low MW and hydrophobic (HPO) DOM was possibly due to the formation of soluble microbial product-like (SMP-like) matters in the reversed A2/O treatment, especially in the anoxic and aerobic processes. Moreover, DOM in the wastewater displayed a high carbonaceous disinfection byproduct formation potential (C-DBPFP) in the fractions of MW>100kDa and MW<5kDa, and revealed an increasing tendency of nitrogenous disinfection byproduct formation potential (N-DBPFP) with decrease of MW. For polarity-based fractions, the HPO fraction of wastewater showed significantly higher C-DBPFP and N-DBPFP than hydrophilic and transphilic fractions. Therefore, although the reversed A2/O process could remove most DBP precursors by DOC reduction, it led to the enhancement of DBPFP with the formation and accumulation of low MW and HPO DOM. In addition, strong correlations between C-DBPFPs and SUVA, and between N-DBPFPs and DON/DOC, were observed in the wastewater, which might be helpful for DBPFP prediction in wastewater and reclaimed water chlorination.


Assuntos
Desinfetantes/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Desinfecção/métodos , Interações Hidrofóbicas e Hidrofílicas , Nitrogênio , Trialometanos/análise , Águas Residuárias/química
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