Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
World J Microbiol Biotechnol ; 35(8): 127, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375931

RESUMO

Aeromonas hydrophila is a Gram-negative bacterium that causes serious infections in aquaculture and exhibits significant multidrug resistance. The LysR-type transcriptional regulator (LTTR) family proteins are a well-known group of transcriptional regulators involved in diverse physiological functions. However, the role of LTTRs in the regulation of bacterial resistance to antibiotics is still largely unknown. In this study, to further investigate the role of four putative LTTR family proteins (A0KIU1, A0KJ82, A0KPK0, and A0KQ63) in antibiotic resistance in A. hydrophila, their genes were cloned and overexpressed in engineered Escherichia coli. After the optimization of experimental conditions including incubation time, temperature, and IPTG concentration, these proteins were successfully purified, and their specific antibodies against mice were obtained. Using western blot analysis, we found that these LTTR family proteins were downregulated in A. hydrophila following antibiotic treatment, indicating that they may be involved in the regulation of antibiotic resistance. Additionally, minimum inhibitory concentration (MIC) assays of chloramphenicol (CM), chlortetracycline (CTC), ciprofloxacin (CF), furazolidone (FZ), and balofloxacin (BF) in E. coli showed that overexpression of these LTTRs led to increased sensitivity to several antibiotics. To further validate their functional role in antibiotic resistance, we demonstrated that bacteria with loss of A0KQ63 (ΔAHA_3980) exhibited multi-drug resistance properties. Our results indicate that these LTTR family proteins may play an important role in the antibiotic resistance of A. hydrophila, and the that underlying mechanisms controlling antibiotic resistance should be further investigated.


Assuntos
Aeromonas hydrophila/efeitos dos fármacos , Aeromonas hydrophila/genética , Farmacorresistência Bacteriana , Regulação Bacteriana da Expressão Gênica , Genes Reguladores , Fatores de Transcrição/metabolismo , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Western Blotting , Clonagem Molecular , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Deleção de Genes , Expressão Gênica , Perfilação da Expressão Gênica , Genes Bacterianos , Camundongos , Testes de Sensibilidade Microbiana , Fatores de Transcrição/análise , Fatores de Transcrição/genética
2.
Emerg Microbes Infect ; 8(1): 1229-1239, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31448697

RESUMO

Lysine acetylation and succinylation are both prevalent protein post-translational modifications (PTMs) in bacteria species, whereas the effect of the cross-talk between both PTMs on bacterial biological function remains largely unknown. Our previously study found lysine succinylated sites on proteins play important role on metabolic pathways in fish pathogenic Aeromonas hydrophila. A total of 3189 lysine-acetylation sites were further identified on 1013 proteins of this pathogen using LC-MS/MS in this study. Functional examination of these PTMs peptides showed associations with basal biological processes, especially metabolic pathways. Additionally, when comparing the obtained lysine acetylome to a previously obtained lysine succinylome, 1198 sites in a total of 547 proteins were found to be in common and associated with various metabolic pathways. As the autoinducer-2 (AI-2) synthase involved in quorum sensing of bacteria, the site-directed mutagenesis of LuxS at the K165 site was performed and revealed that the cross-talk between lysine acetylation and succinylation exerts an inverse influence on bacterial quorum sensing and on LuxS enzymatic activity. In summary, this study provides an in-depth A. hydrophila lysine acetylome profile and for the first time reveals the role of cross-talk between lysine acetylation and succinylation, and its potential impact on bacterial physiological functions.

3.
Int J Mol Sci ; 20(16)2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31430870

RESUMO

Zinc oxide nanoparticles (ZnO NPs) have shown adverse health impact on the human male reproductive system, with evidence of inducing apoptosis. However, whether or not ZnO NPs could promote autophagy, and the possible role of autophagy in the progress of apoptosis, remain unclear. In the current study, in vitro and in vivo toxicological responses of ZnO NPs were explored by using a mouse model and mouse Leydig cell line. It was found that intragastrical exposure of ZnO NPs to mice for 28 days at the concentrations of 100, 200, and 400 mg/kg/day disrupted the seminiferous epithelium of the testis and decreased the sperm density in the epididymis. Furthermore, serum testosterone levels were markedly reduced. The induction of apoptosis and autophagy in the testis tissues was disclosed by up-regulating the protein levels of cleaved Caspase-8, cleaved Caspase-3, Bax, LC3-II, Atg 5, and Beclin 1, accompanied by down-regulation of Bcl 2. In vitro tests showed that ZnO NPs could induce apoptosis and autophagy with the generation of oxidative stress. Specific inhibition of autophagy pathway significantly decreased the cell viability and up-regulated the apoptosis level in mouse Leydig TM3 cells. In summary, ZnO NPs can induce apoptosis and autophagy via oxidative stress, and autophagy might play a protective role in ZnO NPs-induced apoptosis of mouse Leydig cells.

5.
Environ Microbiol ; 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31355499

RESUMO

Although many typical outer-membrane proteins (OMPs) have been well characterized, the biological functions of many OMPs remain largely elusive. In this study, we successfully constructed 29 OMP knockout strains in the pathogen Aeromonas hydrophila, which account for about 50% of all predicted OMPs in this bacterial species. We then further validated the antibiotics' susceptibility characteristics against 20 antimicrobial reagents in these mutants considering several phenotypes. Our results showed that a total of 22 OMP mutants affected the susceptibility to at least one antibiotic. The deletion of some OMPs, such as ΔlamB and ΔbamA, revealed very important roles in the resistance to certain antibiotics. However, not a single OMP mutant presented a constant behaviour to all of the tested antibiotics, suggesting the existence of a complex intercellular regulation mechanism and a protein-protein interaction network underlying the OMP homeostasis in the presence of antibiotics. Meanwhile, some OMP mutants also affected biofilm formation, ECPase and haemolytic activity, and carbon resources utilization. This report demonstrates the biological functions of OMPs on a large scale and most of results have not been reported in A. hydrophila.

6.
Mol Nutr Food Res ; 63(18): e1801356, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31313461

RESUMO

SCOPE: Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disorder, with increasing incidence worldwide but unknown etiology. 6-Gingerol (6-GIN), a major dietary compound found in ginger rhizome, has immunomodulatory activity. However, its role in autoimmune diseases, as well as the underlying mechanisms, are unclear. In this study, it is evaluated if 6-GIN can effectively ameliorate the clinical disease severity of experimental autoimmune encephalomyelitis, an animal model of MS. METHODS AND RESULTS: Clinical scores of experimental autoimmune encephalomyelitis (EAE) mice are recorded daily. Inflammation of periphery and neuroinflammation of EAE mice are determined by flow cytometry analysis, ELISA, and histopathological analysis, and results show that 6-GIN significantly inhibits inflammatory cell infiltration from the periphery into the central nervous system and reduces neuroinflammation and demyelination. Flow cytometry analysis, ELISA, and quantitative PCR show that 6-GIN could suppress lipolysaccharide-induced dendritic cell (DC) activation and induce the tolerogenic DCs. Immunoblot analysis reveals that the phosphorylation of nuclear factor-κB and mitogen-activated protein kinase, two critical regulators of inflammatory signaling, are significantly inhibited in 6-GIN-treated DCs. CONCLUSION: The results of this study demonstrate that 6-GIN has significant potential as a novel anti-inflammatory agent for the treatment of autoimmune diseases such as MS via direct modulatory effects on DCs.

7.
Cell Mol Neurobiol ; 39(8): 1201-1206, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31332666

RESUMO

Trimethylamine N-oxide (TMAO) has emerged as a newly identified gut microbiota-dependent metabolite contributing to a variety of diseases, such as diabetes, atherosclerosis, and cardiovascular diseases. The aim of our study was to determine whether a relatively high TMAO level is associated with an increased risk of poor outcome in ischemic stroke patients. From June 2018 to December 2018, we prospectively recruited acute ischemic stroke patients diagnosed within 24 h of symptom onset. The plasma TMAO level was measured at admission for all patients. Functional outcome was evaluated at 3 months after the stroke using the modified Rankin Scale (mRS) and then dichotomized as favorable (mRS 0-2) or unfavorable (mRS 3-6). A multivariate logistic regression analysis was conducted to evaluate the association between TMAO concentration and poor functional outcome and mortality at 3 months. Of the 225 acute ischemic stroke patients included in the analysis, the median TMAO concentration was 3.8 µM (interquartile range, 1.9-4.8 µM). At 3 months after admission, poor functional outcome was observed in 116 patients (51.6%), and 51 patients had died (22.7%). After adjusting for potential confounders, patients with TMAO levels in the highest quartile were more likely to have higher risks of poor functional outcome [compared with the lowest quartile, odds ratio (OR) 3.63; 95% confidence interval (CI) 1.34-9.82; P = 0.011] and mortality (OR 4.27; 95% CI 1.07-17.07; P = 0.040). Our data suggest that a high plasma TMAO level upon admission may predict unfavorable clinical outcomes in acute ischemic stroke patients.

8.
Sci China Life Sci ; 62(7): 886-894, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31152388

RESUMO

Birth defects are caused by multiple factors, such as chromosome abnormality, environmental factors, and maternal factors. In this study, we focused on exploring the genetic causes of a non-consanguineous couple who suffered from four times of unsuccessful pregnancy due to unexplained recurrent fetal malformations with similar symptoms and normal chromosome copy number variations. Using trio-whole exome sequencing (trio-WES) for this couple and one of the affected fetuses, we found a mutation, c.1996delC on the maternal imprinted gene MAGEL2 that was carried by the affected fetus and husband, leading to Schaaf-Yang syndrome. To screen this mutation, we further performed preimplantation genetic diagnosis (PGD) strategy followed by a gene pedigree validation and pathogenicity analysis. After the transfer of a PGD-screened embryo, a normal newborn without previous abnormal symptoms was born (February 15, 2019). We present the first data that identified a pathogenic gene (MAGEL2 c.1996delC) in a fetus with Schaaf-Yang syndrome in the EAS (East Asian) database and overcame this genetic defect by using processed PGD for this couple based on the WES results.

9.
Sci Total Environ ; 687: 34-40, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202011

RESUMO

This investigation focused on the simultaneous decrease of tannery sludge and the reduction of its high chromium (Cr(VI)) content. This was accomplished through the addition of mixed bacterial strains that were cultured in the laboratory, subsequent to their isolation from tannery sludge. The results indicated that under anaerobic conditions, the amount of the tannery sludge was decreased by 27% with these mixed bacteria. The impacts of various parameters were explored, such as pH, processing duration, strain inoculation, and temperature. Along with the decreased volume of sludge, the Cr(VI) concentration was lowered as well. Among the isolated bacterial strains, WY601 (belonging to Stenotrophomonas sp.) demonstrated the highest Cr(VI) resistance; from an initial concentration of 300 mg L-1, the Cr(VI) level was decreased by 90% within 65 h. Hexavalent chromate reductase was found to be localized primarily within the extracellular membrane or adsorbed to its surface, and a mechanism was proposed for the removal of Cr(VI) via WY601. Further, the WY601 isolate was found to be tolerant to other toxic heavy metals. In summary, the isolated mixed bacterial strains in our study demonstrated a strong potential for the treatment of tannery sludge, as they could simultaneously decrease its volume while lowering high Cr(VI) levels.

10.
Acta Biomater ; 92: 241-253, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31078766

RESUMO

Carbon monoxide (CO)-based gas therapy has emerged as an attractive therapeutic strategy for cancer therapy. However, the main challenges are the in situ-triggered and efficient delivery of CO in tumors, which limit its further clinical application. Herein, we developed an erythrocyte membrane-biomimetic gas nanofactory (MGP@RBC) to amplify the in situ generation of CO for combined energy starvation of cancer cells and gas therapy. This nanofactory was constructed by encapsulating glucose oxidase (GOx) and Mn2(CO)10 (CO-donor) into the biocompatible polymer poly(lactic-co-glycolic acid), obtaining MGP nanoparticles, which are further covered by red blood cell (RBC) membrane. Because of the presence of proteins on RBC membranes, the nanoparticles could effectively avoid immune clearance in macrophages (Raw264.7) and significantly prolong their blood circulation time, thereby achieving higher accumulation at the tumor site. After that, the GOx in GMP@RBC could effectively catalyze the conversion of endogenous glucose to hydrogen peroxide (H2O2) in the presence of oxygen. The concomitant generation of H2O2 could efficiently trigger CO release to cause dysfunction of mitochondria and activate caspase, thereby resulting in apoptosis of the cancer cells. In addition, the depletion of intratumoral glucose could starve tumor cells by shutting down the energy supply. Altogether, the in vitro and in vivo studies of our synthesized biomimetic gas nanofactory exhibited an augmentative synergistic efficacy of CO gas therapy and energy starvation to inhibit tumor growth. It provides an attractive strategy to amplify CO generation for enhanced cancer therapy in an accurate and more efficient manner. STATEMENT OF SIGNIFICANCE: Carbon monoxide (CO) based gas therapy has emerged as an attractive therapeutic strategy for cancer therapy. In this study, we developed an erythrocyte membrane biomimetic gas nanofactory to amplify the in-situ generation of CO for combined cancer starvation and gas therapy. It is constructed by coating glucose oxidase (GOx) and CO donor-loaded nanoparticles with erythrocyte membrane. Due to the erythrocyte membrane, it can effectively prolong blood circulation time and achieve higher tumor accumulation. After accumulated in tumor, endogenous glucose can be effectively catalyzed to hydrogen peroxide, in-situ amplified CO release to induce the apoptosis of cancer cells. In addition, depleting glucose can also starve tumor cells by shutting down the energy supply. Overall, our biomimetic gas nanofactory exhibits an augmentative synergistic efficacy of CO gas therapy and starvation to increased tumor inhibition. It provide a novel strategy to deliver CO in an accurate and more efficient manner, promising for combined cancer therapy in future clinical application.

11.
Biomater Sci ; 7(6): 2559-2570, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-30977484

RESUMO

The photothermal response of nanomaterials provides a basis for many biomedical applications, including diagnosis (e.g., biosensor and photoacoustic imaging) and treatment (e.g., drug delivery and photothermal therapy). The use of nano-materials for cancer phototherapy (solid tumor ablation) can cause cell necrosis and apoptosis. However, photothermal effects using the same material can differ among tumor cell types, and the molecular mechanisms underlying these differences are not clear. We used polydopamine (PDA)-coated branched Au-Ag nanoparticles (Au-Ag@PDA NPs) for the photothermal treatment of two prostate cancer cell lines. The therapeutic effect was evaluated by CCK8, flow cytometry, and expression analyses of related genes by western blotting. Photothermal therapy resulted in oxidative stress in prostate cancer cells and activated the mitochondrial-related apoptosis pathway, increasing the Bax expression. In addition, we observed a greater photothermal treatment effect on the androgen-dependent cells LNCaP than the androgen-independent cells DU145. Pretreatment with an inhibitor of the NF-κB signaling pathway (BAY 11-7082) enhanced the expression of BAX in the DU145 cells and increased the sensitivity of the cells to the heat treatment of Au-Ag@PDA NPs both in vitro and in vivo. Our findings explain the differences in the observed effects of photothermal therapy and provide the direction for further improvements to this strategy.

12.
Front Immunol ; 10: 256, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30833947

RESUMO

In our previous study, several iron-related outer membrane proteins in Aeromonas hydrophila, a serious pathogen of farmed fish, conferred high immunoprotectivity to fish, and were proposed as potential vaccine candidates. However, the protective efficacy of these extracellular proteins against A. hydrophila remains largely unknown. Here, we identified secreted proteins that were differentially expressed in A. hydrophila LP-2 in response to iron starvation using an iTRAQ-based quantitative proteomics method. We identified 341 proteins, of which 9 were upregulated in response to iron starvation and 24 were downregulated. Many of the differently expressed proteins were associated with protease activity. We confirmed our proteomics results with Western blotting and qPCR. We constructed three mutants by knocking out three genes encoding differentially expressed proteins (Δorf01830, Δorf01609, and Δorf03641). The physiological characteristics of these mutants were investigated. In all these mutant strains, protease activity decreased, and Δorf01609, and Δorf01830 were less virulent in zebrafish. This indicated that the proteins encoded by these genes may play important roles in bacterial infection. We next evaluated the immune response provoked by the six iron-related recombinant proteins (ORF01609, ORF01830, ORF01839, ORF02943, ORF03355, and ORF03641) in zebrafish as well as the immunization efficacy of these proteins. Immunization with these proteins significantly increased the zebrafish immune response. In addition, the relative percent survival (RPS) of the immunized zebrafish was 50-80% when challenged with three virulent A. hydrophila strains, respectively. Thus, these extracellular secreted proteins might be effective vaccine candidates against A. hydrophila infection in fish.

13.
J Biomed Nanotechnol ; 15(4): 813-821, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30841973

RESUMO

Photothermal therapy (PTT) is a recently developed and promising strategy for the treatment of hepatocellular carcinoma (HCC). However, apoptosis has been extensively investigated as the mechanism of the underlying effect of PTT on cancer to date. Here, we explored alternative mechanisms of these therapeutic effects, including the activation of cell-cycle arrest and autophagy during PTT in addition to apoptosis under mild temperature. We treated the HCC cell line HepG2 with polydopamine (PDA)-coated branched Au-Ag nanoparticles at various concentrations along with PTT using an 808-nm laser. Apoptosis was evaluated based on flow cytometry, western blot analysis of apoptosis related proteins (BAX, BCL2, caspase 3), Hoechst staining, and TUNEL staining. To explore the role of autophagy, we treated cells with the autophagy inhibitor chloroquine diphosphate. Enhancement of apoptosis by PTT with nanoparticle treatment was observed after autophagy was inhibited. Moreover, inhibition of autophagy markedly enhance the suppression of tumor growth in vivo in a HepG2 mouse xenograft model. These results suggest that further exploration of the mechanism of PTT can help guide its clinical application, and that autophagy inhibition combined with PTT could be a promising strategy for HCC treatment.


Assuntos
Autofagia , Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Apoptose , Linhagem Celular Tumoral , Humanos , Nanopartículas Metálicas , Camundongos , Prata
14.
J Pharm Sci ; 108(7): 2367-2376, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30802455

RESUMO

The purpose of the present study was to make a detailed comparison of 2 similar additives about their opposite effects on the initial burst of octreotide acetate from poly(lactic-co-glycolic acid) microspheres. We focused on identifying the key factor that influenced the initial burst of microspheres induced by small hydrophilic additives. The apparent reason resulting in such differences was different pore closing rates on the surface of these 2 batches. However, the potential mechanism was still unknown. To compare with the single-additive system, these 2 additives were coencapsulated together into the same formulation. Of surprise, the inhibition effect of glucose on burst release somehow disappeared and even turned out to be opposite. This phenomenon greatly reminds us that there must be some interactions between glucose and polymer, which are likely to be disturbed by coencapsulated CaCl2. However, small amount of additive can hardly make any detected difference. Therefore, additive-loaded microspheres without drug were prepared to further investigate the potential factors. Under this condition, differences were found. The key factor for glucose-induced accelerated pore closure and reduction in initial burst was the formation of hydrogen bonds between the glucose molecule and the polymer matrix.

15.
Methods Mol Biol ; 1894: 345-352, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30547472

RESUMO

Daphnia magna (D. magna), an aquatic invertebrate, is the most commonly used test organism in ecotoxicological studies on manufactured nanomaterials (MNs). Although standard protocols for undertaking acute and chronic toxicity tests of dissolved chemicals with D. magna have been endorsed by several national and international organizations, comprehensive guidance on aquatic toxicology testing of MNs with D. magna are in their infancy. Here we describe the acute and chronic toxicity methods with D. magna as test organism for nanoecotoxicity study. These methods may provide reference for the next step toward developing prescriptive aquatic toxicity standard tests for MNs with D. magna.


Assuntos
Daphnia , Monitoramento Ambiental/métodos , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/normas , Guias como Assunto , Testes de Toxicidade Aguda/instrumentação , Testes de Toxicidade Aguda/métodos , Testes de Toxicidade Crônica/instrumentação , Testes de Toxicidade Crônica/métodos
16.
Oncol Rep ; 41(3): 1929-1937, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30592283

RESUMO

Alternative splicing (AS) is a transcriptional regulation mechanism that participates in multiple aspects of cancer. The present study aimed to identify differential AS events from tumor and non­tumor samples and investigate the potential of AS as a source of candidate cancer diagnostic biomarkers. Deep RNA sequencing of three paired hepatocellular carcinoma (HCC) tumors and adjacent non­tumors was applied to identify AS events. RT­qPCR was performed on 45 HCC clinical samples to validate the splicing differences. The maximal information coefficient was first used to build an association between clinical features and AS changes. We identified 197 significantly differential skipped exon events, of which only 29% overlapped with the differentially expressed genes. The differentially spliced genes were mainly enriched in HCC­characterized biological processes and pathways, clearly separating tumors from non­tumors. We also validated the statistically significant splicing differences of three AS candidates (CEACAM1 exon 7, VPS29 exon 2 and ISOC2 exon 3). Furthermore, a clinicopathological analysis revealed that carcinoembryonic antigen­related cell adhesion molecule 1 (CEACAM1) exon 7 was significantly correlated with the survival time, and VPS29 exon 2 was associated with cell differentiation stages. In conclusion, the findings of the three AS candidates in the present study could be beneficial in HCC prognosis and new treatment strategies.


Assuntos
Processamento Alternativo , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/diagnóstico , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/diagnóstico , Adulto , Antígenos CD/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , Moléculas de Adesão Celular/genética , Éxons/genética , Feminino , Humanos , Hidrolases/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Isoformas de Proteínas/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de RNA , Análise de Sobrevida , Proteínas de Transporte Vesicular/genética
17.
Mol Ther Methods Clin Dev ; 11: 83-91, 2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30417023

RESUMO

Allergic rhinitis (AR) involves antigen-specific immune-inflammation of the nasal mucosa. Classical therapy for AR targets the histamine pathway, e.g., histamine receptor blockers. Histamine H4 receptor (H4R) was suggested as a novel therapeutic target due to its wide expression on almost all immune-related cells. A 12-mer random peptide library was used to select the specific epitope of the H4R. The phage clone showing the highest degree of activation was verified and translated to the corresponding peptide. The peptide FNKWMDCLSVTH, designated as P-FN12, was bound by H4R monoclonal antibody (mcAb) with high affinity. Moreover, the P-FN12 + CTB@Lipo-formulated vaccine, used as nasal drops, decreased allergic symptoms such as sneezing and nasal rubbing in a rat model. The level of ovalbumin (OVA)-specific immunoglobulin E (IgE) decreased significantly after vaccine administration. It also elicited increased levels of interferon (IFN)-γ and interleukin-2 (IL-2) but a decreased level of IL-4, and it elevated the T helper type 1 (Th1):T helper type 2 (Th2) cell ratio in peripheral blood mononuclear cell cultures. Our results indicated that the reduction of allergic inflammation by P-FN12-based vaccine was related to a decrease in production of OVA-specific IgE, Th2 immunity, and tissue eosinophilia. P-FN12 + CTB@Lipo is a promising vaccine that could suppress Th2 response and enhance the induction of Th1 cells in an AR model.

18.
Int J Nanomedicine ; 13: 6413-6428, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30410328

RESUMO

Purpose: Polydopamine-coated branched Au-Ag nanoparticles (Au-Ag@PDA NPs) exhibit good structural stability, biocompatibility, and photothermal performance, along with potential anticancer efficacy. Here, we investigated the cytotoxicity of Au-Ag@PDA NPs against human bladder cancer cells (T24 cells) in vitro and in vivo, as well as the underlying molecular mechanisms of photothermal therapy-induced T24 cell death. Materials and methods: T24 cells were treated with different doses of Au-Ag@PDA NPs followed by 808 nm laser irradiation, and the effects on cell proliferation, cell cycle, apoptosis, and autophagy were analyzed. To confirm the mechanisms of inhibition, real-time PCR and Western blot analysis were used to evaluate markers of cell cycle, apoptosis, autophagy, and the AKT/ERK signaling pathway. Moreover, we evaluated the effects of the treatment on mitochondrial membrane potential and ROS generation to confirm the underlying mechanisms of inhibition. Finally, we tested the T24 tumor inhibitory effects of Au-Ag@PDA NPs plus laser irradiation in vivo using a xenograft mouse model. Results: Au-Ag@PDA NPs, with appropriate laser irradiation, dramatically inhibited the proliferation of T24 cells, altered the cell cycle distribution by increasing the proportion of cells in the S phase, induced cell apoptosis by activating the mitochondria-mediated intrinsic pathway, and triggered a robust autophagy response in T24 cells. Moreover, Au-Ag@PDA NPs decreased the expression of phosphorylated AKT and ERK and promoted the production of ROS that function upstream of apoptosis and autophagy. In addition, Au-Ag@PDA NP-mediated photothermolysis also significantly suppressed tumor growth in vivo. Conclusion: This preclinical study can provide a mechanistic basis for Au-Ag@PDA NP-mediated photothermal therapy toward promotion of this method in the clinical treatment of bladder cancer.

19.
Artigo em Inglês | MEDLINE | ID: mdl-30460208

RESUMO

Outer membrane proteins (OMPs) play essential roles in antibiotic resistance, particularly in Gram-negative bacteria; however, they still have many unidentified functions regarding their behavior in response to antibiotic stress. In the current work, quantitative tandem mass tag labeling-based mass spectrometry was used to compare the outer membrane related proteins between an oxytetracycline-resistant (OXY-R) and its original control stain (OXY-O) in Aeromonas hydrophila. Consequently, a total of 261 commonly altered proteins in two biological repeats were identified including 29 proteins that increased and 28 that decreased. Gene ontology analysis showed that the expression of transport proteins was significantly reduced, and translation-related proteins were downregulated in the OXY-R strain. After using western blotting to validate selected altered proteins, eight OMP-related genes were knocked out and their roles in antibiotic resistance were further evaluated. The survival assays showed that some mutants such as ΔAHA_4281, ΔAHA_2766, ΔAHA_2282, ΔAHA_1181, and ΔAHA_1280 affected the susceptibility of A. hydrophila to antimicrobials. Moreover, the minimum inhibitory concentration assay showed that these candidate mutants also respond differently to other types of antibiotics. Our results reveal several novel outer membrane related proteins of A. hydrophila that play important roles in antibiotic resistance, and as such, may be helpful for screening studies to identify novel drug targets.

20.
Appl Microbiol Biotechnol ; 102(24): 10523-10539, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30338358

RESUMO

Pseudomonas putida KT2442, a natural producer of polyhydroxyalkanoate, spends a lot of energy and carbon sources to form flagella and pili; therefore, deleting the genes involved in the biosynthesis and assembly of flagella and pili might improve PHA productivity. In this study, two novel deletion systems were constructed in order to efficiently remove the 76 genes involved in the biosynthesis and assembly of flagella and pili in P. putida KT2442. Both systems combine suicide-plasmid-based homologous recombination and mutant lox site-specific recombination and involve three plasmids. The first includes pK18mobsacB, pWJW101, and pWJW102; and the second includes pZJD29c, pDTW202, and pWJW103. These newly constructed systems were successfully used to remove different gene clusters in P. putida KT2442 and showed a high deletion efficiency (above 90%) whether for the second-round or the third-round recombination. Both systems could efficiently delete the gene PP4378 encoding flagellin in putida KT2442, resulting in the mutant strain WJPP01. The second system was used to remove the pili-forming gene cluster PP2357-PP2363 in putida KT2442, resulting in the mutant strain WJPP02, and also used to remove the flagella-forming gene cluster PP4329-PP4397 in WJPP02, resulting in the mutant strain WJPP03. Compared with the wild-type KT2442, the 1.2% genome reduction mutant WJPP03 grew faster, lacked flagella and motility, showed sharply decreased biofilm and 3',5'-cyclic diguanylic acid (c-di-GMP), but accumulated more polyhydroxyalkanoate. The biomass, polyhydroxyalkanoate yield, and content of WJPP03 increased 19.1, 73.4, and 45.6%, respectively, with sodium hexanoate supplementation, and also increased 11.4, 53.6, and 37.9%, respectively, with lauric acid supplementation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA