Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Microb Pathog ; 189: 106590, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38402917

RESUMO

CONTEXT: Changes in the gut microbiome are linked with Type 2diabetes mellitus (T2DM) development, but alterations in patients with diabetic retinopathy (DR) are still being debated. OBJECTIVE: To investigate the differences in biodiversity and relative abundance of gut microbiome between patients with DR and T2DM. METHODS: A comprehensive search was performed in five electronic databases (PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and CNKI) from the inception of each database through to August 2023. The standardized mean difference (SMD) and its 95% confidence interval (CI) were estimated using Stata 15.1. Furthermore, the alpha diversity index and relative abundance of the gut microbiome were calculated. The Egger test determined publication bias in the literature. RESULTS: Seven case-control studies were included in the final dataset, comprising 195 patients with DR and 211 patients with T2DM. Compared to T2DM patients, patients in the DR group had a reduced but not significantly different α-diversity. The analysis of microbial composition at the phylum level revealed a marked increase in the relative abundance of Bacteroidetes(ES = 23.27, 95%CI[8.30, 38.23], P = 0.000) and a decline in Firmicutes(ES = 47.05, 95%CI[36.58, 57.52], P = 0.000), Proteobacteria (ES = 11.08, 95%CI[6.08, 16.07], P = 0.000) and Actinobacteria (ES = 10.43, 95%CI[1.64, 19.22], P = 0.001) in patients with DR when compared to those with T2DM. CONCLUSIONS: An association exists between alterations in the gut microbiome of T2DM and the development and progression of DR. This suggests that re-establishing homeostasis of the gut microbiome could be a potential way to prevent or treat DR and requires further confirmation in future studies. REGISTRATION DATABASE: Prospero. REGISTRATION NUMBER: CRD42023455280.


Assuntos
Diabetes Mellitus Tipo 2 , Retinopatia Diabética , Microbioma Gastrointestinal , Humanos , Diabetes Mellitus Tipo 2/complicações , Estudos de Casos e Controles
2.
BMC Med Genomics ; 16(1): 287, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37968618

RESUMO

BACKGROUND: As the most common type of glaucoma, the etiology of primary open-angle glaucoma (POAG) has not been unified. Autophagy may affect the occurrence and development of POAG, while the specific mechanism and target need to be further explored. METHODS: The GSE27276 dataset from the Gene Expression Omnibus (GEO) database and the autophagy gene set from the GeneCards database were selected to screen differentially expressed autophagy-related genes (DEARGs) of POAG. Hub DEARGs were selected by constructing protein-protein interaction (PPI) networks and utilizing GSE138125 dataset. Subsequently, immune cell infiltration analysis, genome-wide association study (GWAS) analysis, gene set enrichment analysis (GSEA) and other analyses were performed on the hub genes. Eventually, animal experiments were performed to verify the mRNA levels of the hub genes by quantitative real time polymerase chain reaction (qRT-PCR). RESULTS: A total of 67 DEARGs and 2 hub DEARGs, HSPA8 and RPL15, were selected. The hub genes were closely related to the level of immune cell infiltration. GWAS analysis confirmed that the causative regions of the 2 hub genes in glaucoma were on chromosome 11 and chromosome 3, respectively. GSEA illustrated that pathways enriched for highly expressed HSPA8 and RPL15 contained immunity, autophagy, gene expression and energy metabolism-related pathways. qRT-PCR confirmed that the expression of Hspa8 and Rpl15 in the rat POAG model was consistent with the results of bioinformatics analysis. CONCLUSIONS: This study indicated that HSPA8 and RPL15 may affect the progression of POAG by regulating autophagy and provided new ideas for the pathogenesis and treatment of POAG.


Assuntos
Glaucoma de Ângulo Aberto , Glaucoma , Animais , Ratos , Humanos , Estudo de Associação Genômica Ampla , Glaucoma de Ângulo Aberto/genética , Cromossomos Humanos Par 11 , Autofagia/genética
3.
Eur J Clin Microbiol Infect Dis ; 42(10): 1195-1205, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37604947

RESUMO

PURPOSE: Highly active antiretroviral therapy (HAART) is an accepted treatment option for patients with virus infection. Mounting evidence indicated that persistent HAART treatment is implicated with increased morbidity of HIV-associated neurocognitive disorders (HAND) in patients. Tenofovir disoproxil fumarate (TDF), a novel nucleotide reverse transcriptase inhibitor (NRTI), was used in patients with HIV co-infected with HBV. And it is still a vital first-line antiretroviral compounds in HAART. However, whether persistent treatment with TDF is involved in HAND development remains to be further elucidated. In this study, we aimed to discuss the neurotoxicity of TDF. METHODS: We used SH-SY5Y cells and primary neuronal cells to evaluate the neurotoxicity of TDF in vitro. The cytotoxicity of TDF on SH-SY5Y cells and primary neuronal cells was evaluated by the cell viability and LDH levels by MTT assay and LDH kit, respectively. Hoechst 33342 staining, TUNEL assay and flow cytometry were performed to evaluate the cells apoptosis. The intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) production were measured by commercial kits. In addition, the activation level of caspase-3 was evaluated using spectrophotometry and western blotting. RESULTS: Our results showed that TDF treatment significantly induced cell viability and induced apoptosis of SH-SY5Y cells and primary neuronal cells. Furthermore, the ROS levels and MDA productions were significantly up-regulated in nerve cells treated with TDF.  CONCLUSION: Our findings indicated that TDF may induce neuronal cell apoptosis through increasing the intracellular ROS and the expression level of caspase-3, which may be related to the increasing prevalence of HAND.


Assuntos
Neuroblastoma , Humanos , Tenofovir/toxicidade , Caspase 3 , Espécies Reativas de Oxigênio , Neurônios
4.
BMC Microbiol ; 22(1): 205, 2022 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-35996113

RESUMO

BACKGROUND: Bacteria usually secrete a variety of extracellular enzymes to degrade extracellular macromolecules to meet their nutritional needs and enhance their environmental adaptability. Bacillus cereus 0-9, a biocontrol bacterial strain isolated from wheat roots, has three genes annotated as encoding amylases in the genome, but their functions are unknown, and whether they are involved in the colonization process of the bacterium remains to be further studied. METHODS: Mutant gene strains and fluorescently tagged strains were constructed by homologous recombination, and amylase protein was expressed in the prokaryotic Escherichia coli BL21(DE3) expression system. The iodine staining method was used to measure the activity of amylase proteins. We further observed the colonization abilities of the test strains in wheat roots through frozen section technology. RESULTS: The results showed that there were three amylase-encoding genes, amyC, amyP and amyS, in the B. cereus 0-9 genome. Among the three amylase encoding genes, only amyS produced extracellular amylase whose secretion was related to signal peptide at position 1-27. The AmyS protein encoded by the amyS gene is an α-amylase. The growth of Rhizoctonia cerealis was inhibited 84.7% by B. cereus 0-9, but the biocontrol ability of the ΔamyS strain decreased to 43.8% and that of ΔamyS/amyS was restored when the amyS gene was complemented. Furthermore, the biocontrol ability of the ΔamySec strain was decreased to 46.8%, almost the same as that of the ΔamyS mutant. Due to the deletion of the amyS gene, the colonization capacities of ΔamyS (RFP) and ΔamySec (RFP) in wheat roots decreased, while that of ΔamyS/amyS (RFP) was restored after the amyS gene was complemented, indicating that the amyS gene influences the colonization of B. cereus 0-9 in wheat roots. In addition, the colonization and biocontrol abilities of the mutant were restored after the addition of sugars, such as glucose and maltose. CONCLUSIONS: B. cereus 0-9 encodes three genes annotated as amylases, amyC, amyP and amyS. Only the deletion of the amyS gene with a signal peptide did not produce extracellular amylase. The AmyS protein encoded by the amyS gene is an α-amylase. Our results indicated that the amyS gene is closely related to the colonization abilities of B. cereus 0-9 in wheat roots and the biocontrol abilities of B. cereus 0-9 to fight against R. cerealis. The extracellular amylase produced by B. cereus 0-9 can hydrolyze starch and use glucose, maltose and other nutrients to meet the needs of bacterial growth. Therefore, it is very possible that the secretion and hydrolytic activities of extracellular amylase can promote the colonization of B. cereus 0-9 in wheat roots and play important roles in the prevention and control of plant diseases. Our results contribute to exploring the mechanisms of microbial colonization in plant roots.


Assuntos
Bacillus cereus , Triticum , Amilases/genética , Amilases/metabolismo , Bacillus cereus/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Glucose/metabolismo , Maltose , Raízes de Plantas/microbiologia , Sinais Direcionadores de Proteínas , Triticum/microbiologia , alfa-Amilases/genética , alfa-Amilases/metabolismo
5.
FEMS Microbiol Lett ; 369(1)2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35293995

RESUMO

In this study, eight rap-related genes were found in the Bacillus cereus 0-9 genome; five rap genes were located on chromosomes and three on large plasmids. A total of five Rap proteins in B. cereus 0-9 were annotated as 'tetratricopeptide repeat proteins'. SMART Server analysis showed that the eight Rap proteins had typical tetrapeptide repeat sequence (TPR) domains. Biofilm assays and crystal violet staining showed that overexpression of the rapp1 and rap5 genes affected the biofilm formation of B. cereus 0-9, and the activities of Rapp1 and Rap5 proteins were inhibited by their corresponding cognate Phr, suggesting that the Rap-Phr quorum sensing (QS) system might also exist in the B. cereus 0-9 strain. In addition, overexpression of rap1 genes inhibited in the extracellular amylase decomposition capacity of B. cereus 0-9. The results of the sporulation assay indicated that overexpression of the eight rap genes inhibited the spore formation of B. cereus 0-9 to varying degrees. These results provide a reference for research on the regulation of the Rap-Phr QS system in B. cereus.


Assuntos
Bacillus cereus , Proteínas de Bactérias , Bacillus cereus/genética , Bacillus cereus/metabolismo , Proteínas de Bactérias/metabolismo , Biofilmes , Plasmídeos , Percepção de Quorum/fisiologia
6.
BMC Microbiol ; 22(1): 9, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986788

RESUMO

BACKGROUND: Peanut stem rot is a serious plant disease that causes great economic losses. At present, there are no effective measures to prevent or control the occurrence of this plant disease. Biological control is one of the most promising plant disease control measures. In this study, Pseudomonas chlororaphis subsp. aurantiaca strain zm-1, a bacterial strain with potential biocontrol properties isolated by our team from the rhizosphere soil of Anemarrhena asphodeloides, was studied to control this plant disease. METHODS: We prepared extracts of Pseudomonas chloroaphis zm-1 extracellular antibacterial compounds (PECEs), determined their antifungal activities by confrontation assay, and identified their components by UPLC-MS/MS. The gene knockout strains were constructed by homologous recombination, and the biocontrol efficacy of P. chlororaphis zm-1 and its mutant strains were evaluated by pot experiments under greenhouse conditions and plot experiments, respectively. RESULTS: P. chlororaphis zm-1 could produce extracellular antifungal substances and inhibit the growth of Sclerotium rolfsii, the main pathogenic fungus causing peanut stem rot. The components of PECEs identified by UPLC-MS/MS showed that three kinds of phenazine compounds, i.e., 1-hydroxyphenazine, phenazine-1-carboxylic acid (PCA), and the core phenazine, were the principal components. In particular, 1-hydroxyphenazine produced by P. chlororaphis zm-1 showed antifungal activities against S. rolfsii, but 2-hydroxyphenazine did not. This is quite different with the previously reported. The extracellular compounds of two mutant strains, ΔphzH and ΔphzE, was analysed and showed that ΔphzE did not produce any phenazine compounds, and ΔphzH no longer produced 1-hydroxyphenazine but could still produce PCA and phenazine. Furthermore, the antagonistic ability of ΔphzH declined, and that of ΔphzE was almost completely abolished. According to the results of pot experiments under greenhouse conditions, the biocontrol efficacy of ΔphzH dramatically declined to 47.21% compared with that of wild-type P. chlororaphis zm-1 (75.63%). Moreover, ΔphzE almost completely lost its ability to inhibit S. rolfsii (its biocontrol efficacy was reduced to 6.19%). The results of the larger plot experiments were also consistent with these results. CONCLUSIONS: P. chlororaphis zm-1 has the potential to prevent and control peanut stem rot disease. Phenazines produced and secreted by P. chlororaphis zm-1 play a key role in the control of peanut stem rot caused by S. rolfsii. These findings provide a new idea for the effective prevention and treatment of peanut stem rot.


Assuntos
Agentes de Controle Biológico/metabolismo , Doenças das Plantas/prevenção & controle , Pseudomonas/metabolismo , Antibiose/genética , Antifúngicos/análise , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Arachis , Proteínas de Bactérias/genética , Basidiomycota/efeitos dos fármacos , Basidiomycota/crescimento & desenvolvimento , Agentes de Controle Biológico/análise , Mutação , Fenazinas/análise , Fenazinas/metabolismo , Fenazinas/farmacologia , Doenças das Plantas/microbiologia , Pseudomonas/genética
7.
Eur J Ophthalmol ; 32(1): 193-199, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33827296

RESUMO

PURPOSE: To demonstrate the underlying genetic defect that contribute to inherited cataract in a northern Chinese pedigree. METHODS: The study recruited a family pedigree with a diagnosis of bilateral coronary cataract with blue punctate opacities. Fourteen family members and 100 healthy volunteers were enrolled. DNA sample of the proband in this family were analyzed by high-throughput sequencing, which was then demonstrated by Sanger sequencing in the remained people in the family and 100 controls. The functional effect of mutant genes was investigated via bioinformatics analysis, including Polymorphism Phenotyping version2 (PolyPhen-2), Protein Variation Effect Analyzer (PROVEAN v1.1.3) Scale-Invariant Feature Transform (SIFT), and Mutation Taster. RESULTS: In this three-generation family, a novel heterozygous mutation was found in the kinase domain of CRYBA1 gene (c.340C > T, p.R114C), which was only detected in patients in the family with inherited cataract and were not detected in the remained people in the family nor in normal people. The pathogenic effect of the mutation was verified via bioinformatics analysis. CONCLUSION: Our study presented the molecular experiments to confirm that a novel missense mutation of c.340 C > T located in exon 4 of CRYBA1 gene results in a bilateral coronary cataract with blue punctate opacities, which enriches the mutation spectrum of CRYBA1 gene in inherited cataract and deepens the understanding of the pathogenesis of inherited cataract.


Assuntos
Catarata , Mutação de Sentido Incorreto , Cadeia A de beta-Cristalina , Catarata/genética , China , Análise Mutacional de DNA , Humanos , Linhagem , Cadeia A de beta-Cristalina/genética
8.
BMC Cancer ; 21(1): 1307, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34876051

RESUMO

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is the most predominant primary malignant tumor among worldwide, especially in China. To date, the successful treatment remains a mainly clinical challenge, it is imperative to develop successful therapeutic agents. METHODS: The anti-proliferative effect of ivermectin on ESCC is investigated in cell model and in nude mice model. Cell apoptosis was assessed using flow cytometry, TUNEL assay and western blotting. Mitochondrial dysfunction was determined by reactive oxygen species accumulation, mitochondrial membrane potential and ATP levels. RESULTS: Our results determined that ivermectin significantly inhibited the proliferation of ESCC cells in vitro and in vivo. Furthermore, we found that ivermectin markedly mediated mitochondrial dysfunction and induced apoptosis of ESCC cells, which indicated the anti-proliferative effect of ivermectin on ESCC cells was implicated in mitochondrial apoptotic pathway. Mechanistically, ivermectin significantly triggered ROS accumulation and inhibited the activation of NF-κB signaling pathway and increased the ratio of Bax/Bcl-2. CONCLUSIONS: These finding indicated that ivermectin has significant anti-tumour potential for ESSC and may be a potential therapeutic candidate against ESCC.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Ivermectina/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
9.
BMC Microbiol ; 21(1): 172, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34102998

RESUMO

BACKGROUND: Bacillus cereus 0-9, a Gram-positive, endospore-forming bacterium isolated from healthy wheat roots in our previous research, is considered to be an effective biocontrol strain against several soil-borne plant diseases. SpoVG, a regulator that is broadly conserved among many Gram-positive bacteria, may help this organism coordinate environmental growth and virulence to survive. This study aimed to explore the multiple functions of SpoVG in B. cereus 0-9. METHODS: The gene knockout strains were constructed by homologous recombination, and the sporulation process of B. cereus 0-9 and its mutants were observed by fluorescence staining method. We further determined the spore yields and biofilm formation abilities of test strains. Transcriptional fusion strains were constructed by overlapping PCR technique, and the promoter activity of the target gene was detected by measuring its fluorescence intensity. The biofilm production and colonial morphology of B. cereus 0-9 and its mutants were determined to study the functions of the target genes, and the transcription level of the target gene was determined by qRT-PCR. RESULTS: According to observation of the sporulation process of B. cereus 0-9 in germination medium, SpoVG is crucial for regulating sporulation stage V of B. cereus 0-9, which is identical to that of Bacillus subtilis but differs from that of Bacillus anthracis. In addition, SpoVG could influence biofilm formation of B. cereus 0-9. The transcription levels of two genes closely related to biofilm-formation, sipW and calY, were downregulated in a ΔspoVG mutant. The role of SpoVG in regulating biofilm formation was further explored by deleting the genes abrB and sinR in the ΔspoVG mutant, respectively, generating the double mutant strains ΔspoVGΔabrB and ΔspoVGΔsinR. The phenotypes of these double mutants were congruent with those of the single abrB and sinR deletion strains, respectively, which showed increased biofilm formation. This indicated that spoVG was located upstream of abrB and sinR in the regulatory pathway of B. cereus biofilm formation. Further, the results of qRT-PCR and the luminescence intensity of transcriptional fusion strains indicated that spoVG gene deletion could inhibit the transcription of Spo0A. CONCLUSIONS: SpoVG, an important regulator in the sporulation of B. cereus, is located upstream of Spo0A and participates in regulation of biofilm formation of B. cereus 0-9 through regulating the transcription level of spo0A. Sporulation and biofilm formation are crucial mechanisms by which bacteria respond to adverse conditions. SpoVG is therefore an important regulator of Spo0A and is crucial for both sporulation and biofilm formation of B. cereus 0-9. This study provides a new insight into the regulatory mechanism of environmental adaptation in bacteria and a foundation for future studies on biofilm formation of B. cereus.


Assuntos
Bacillus cereus/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Esporos Bacterianos/crescimento & desenvolvimento , Fatores de Transcrição/metabolismo , Bacillus cereus/genética , Bacillus cereus/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Regiões Promotoras Genéticas , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo , Fatores de Transcrição/genética , Transcrição Gênica
10.
Eur J Ophthalmol ; 31(3): 1064-1069, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32223445

RESUMO

OBJECTIVE OF THE STUDY: To identify the pathogenic gene and mutation site of a Chinese family with congenital cataract. METHODS: Eight family members and 100 controls were employed, and targeted exome sequencing was used to identify the genetically pathogenic factor of the proband. RESULTS: Targeted next-generation sequencing identified a novel missense mutation c.209A>C (p.Q70P) of CRYBB1 gene in the family. Sanger sequencing results showed that this heterozygous mutation was a causative mutation, which was not found in unaffected family members and healthy controls. Bioinformatics predicts that the effect of this mutation on protein function is probably harmful. CONCLUSION: We demonstrate that c.209A>C of CRYBB1 gene is a pathogenic mutation in the family of congenital nuclear cataract in this study. This is the first report that this mutation leads to congenital nuclear cataract, which broadens the mutation spectrum of CRYBB1 gene in congenital nuclear cataract.


Assuntos
Catarata , Cadeia B de beta-Cristalina , Povo Asiático/genética , Catarata/genética , China/epidemiologia , Análise Mutacional de DNA , Humanos , Mutação , Mutação de Sentido Incorreto , Linhagem , Cadeia B de beta-Cristalina/genética
11.
Front Microbiol ; 11: 591926, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33365021

RESUMO

Bacillus cereus 0-9, a Gram-positive endospore-forming bacterium isolated from healthy wheat roots, has biological control capacity against several soil-borne plant diseases of wheat such as sharp eyespot and take-all. The bacterium can produce various biofilms that differ in their architecture and formation mechanisms, possibly for adapting to different environments. The gapB gene, encoding a glyceraldehyde-3-phosphate dehydrogenase (GAPDH), plays a key role in B. cereus 0-9 biofilm formation. We studied the function of GapB and the mechanism of its involvement in regulating B. cereus 0-9 biofilm formation. GapB has GAPDH activities for both NAD+- and NADP+-dependent dehydrogenases and is a key enzyme in gluconeogenesis. Biofilm yield of the ΔgapB strain decreased by 78.5% compared with that of wild-type B. cereus 0-9 in lysogeny broth supplemented with some mineral salts (LBS), and the ΔgapB::gapB mutants were recovered with gapB gene supplementation. Interestingly, supplementing the LBS medium with 0.1-0.5% glycerol restored the biofilm formation capacity of the ΔgapB mutants. Therefore, GapB regulates biofilm formation relative to its function in gluconeogenesis. To illustrate how GapB is involved in regulating biofilm formation through gluconeogenesis, we carried out further research. The results indicate that the GapB regulated the B. cereus 0-9 biofilm formation independently of the exopolysaccharides and regulatory proteins in the typical SinI/R system, likely owing to the release of extracellular DNA in the matrix. Transcriptome analysis showed that the gapB deletion caused changes in the expression levels of only 18 genes, among which, lrgAB was the most significantly increased by 6.17-fold. We confirmed this hypothesis by counting the dead and living cells in the biofilms and found the number of living cells in the biofilm formed by the ΔgapB strain was nearly 7.5 times than that of wild-type B. cereus 0-9. Therefore, we concluded that the GapB is involved in the extracellular DNA release and biofilm formation by regulating the expression or activities of LrgAB. These results provide a new insight into the regulatory mechanism of bacterial biofilm formation and a new foundation for further studying the stress resistance of B. cereus.

12.
World J Microbiol Biotechnol ; 36(11): 165, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33000364

RESUMO

YmdB, which can regulate biofilm formation independently, has been reported to exist in Bacillus subtilis. The B. cereus 0-9 genome also encodes a YmdB-like protein, which has measureable phosphodiesterase activity, and 72.35% sequence identity to YmdB protein of B. subtilis 168. In this work, we studied the function of YmdB protein and its encoding gene, ymdB, in B. cereus 0-9. Our results indicated that YmdB protein is critical for the biofilm formation of B. cereus 0-9. In ΔymdB mutant, the transcriptional levels of sinR and hag were up-regulated, and those of genes closely related to biofilm formation, such as sipW, tasA and calY, were down-regulated. Deletion of ymdB gene stimulates the swarming motility of B. cereus 0-9, and enhances it to travel outward, but reduces its ability to form complex spatial structures on the solid surface of MSgg plates. Hence, it is considered that YmdB plays a key role in biofilm formation, and this effect is likely achieved through the function of repressor SinR in B. cereus 0-9. Furthermore, by comparing the amino acid sequences of YmdB by Basic Local Alignment Search Tool (BLAST) in Genebank, we found that YmdB homologues are present in a variety of bacteria (Including Gram-negative bacteria) except B. subtilis and B. cereus. All these bacteria come at different evolutionary distances and belong to different genera. Therefore, we believe that YmdB exists in many types of bacteria and plays an important role in the stress-resistance of bacteria to adapt to the environment. These results can help us to further understand the biocontrol characteristics of B. cereus 0-9.


Assuntos
Bacillus cereus/genética , Bacillus cereus/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Sequência de Aminoácidos , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Deleção de Genes
13.
Molecules ; 25(20)2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076321

RESUMO

Chinese herbs are a useful resource bank for natural drug development, and have attracted considerable attention to exploit quorum sensing inhibitors (QSIs). This study was designed to screen QSIs from raw Chinese herb materials. Of the 38 common herbs examined, the ethanol extract of Campsis grandiflora flower had the strongest QSI activity. The C. grandiflora flower ethanol extract (CFEE) was purified by HPD600, and the QSI activities were examined in further detail. CFEE inhibited violacein production of Chromobacterium violaceum 026 in a dose-dependent manner, and inhibit the swarming abilities of Escherichia coli K-12 and Pseudomonas aeruginosa PAO1. Furthermore, CFEE could inhibited biofilm formation and destroyed mature biofilms of E. coli K-12 and P. aeruginosa PAO1. The composition of CFEE was determined by UPLC-MS/MS to distinguish active QSI compounds, and 21 compounds were identified. In addition to gallic acid and caffeic acid, two organic acids, malic acid and succinic acid, were confirmed for the first time to have autoinducer type 1 QSI activities. Therefore, CFEE is a potential QSI that could be used as a novel antimicrobial agent and should be considered for medicinal development.


Assuntos
Bignoniaceae/química , Medicamentos de Ervas Chinesas/química , Extratos Vegetais/farmacologia , Percepção de Quorum/efeitos dos fármacos , Ácidos/química , Ácidos/farmacologia , Biofilmes/efeitos dos fármacos , China , Medicamentos de Ervas Chinesas/farmacologia , Etanol/química , Flores/química , Humanos , Extratos Vegetais/química
14.
World J Microbiol Biotechnol ; 36(1): 12, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897767

RESUMO

Superoxide dismutases (SODs) have been shown to exhibit high levels of conservation and exist in almost all aerobic organisms and even many strict anaerobes. There are four SODs in Bacillus cereus 0-9, and this coexistence of multiple homologous enzymes is of great significance in the evolution of bacteria. We hypothesized that the four sod genes in B. cereus 0-9 constituted non-redundant protection against oxidative damage in vivo and played unique roles in the pathogenicity of B. cereus 0-9 during different phases or growth environments. To test this hypothesis, we constructed four single-knockout mutants (∆sodA1, ∆sodA2, ∆sodS, and ∆sodC) and a mutant lacking all four sod genes (∆sod-4) of B. cereus 0-9 and assessed their various phenotypes. Our results indicated that sodA1 plays a major role in tolerance to intracellular oxidative stress and spore formation. The ∆sodA1 and ∆sod-4 mutants were very sensitive to oxidants. The spore formation of the ∆sodA1 mutant was dramatically delayed, and the ∆sod-4 mutant did not form any spores under our experimental conditions. The sodA2 gene may play an important role in negative regulation of swarming motility, pathogenicity, and phospholipase and haemolytic activity of B. cereus but also a role in positive regulation of biofilm formation under our experimental conditions. The other two genes, sodS and sodC, were key to the pathogenicity of B. cereus. The lethal rates of Helicoverpa armigera infected by the ∆sodS and ∆sodC mutants were only 26.67%, while wild-type B. cereus 0-9 caused lethality in up to 86.67% of the insects at 24 h after injection. Moreover, the ∆sod-4 mutant caused a reduced death rate of H. armigera of 46.70%, which was slightly higher than that caused by the ∆sodS and ∆sodC strains. Thus, these four sod genes were non-redundant for oxidative stress and may play different additional roles in B. cereus 0-9. These results can help us to further understand the biocontrol characteristics of B. cereus 0-9 and lay a theoretical foundation for further research.


Assuntos
Bacillus cereus/crescimento & desenvolvimento , Lepidópteros/microbiologia , Superóxido Dismutase/genética , Animais , Bacillus cereus/enzimologia , Bacillus cereus/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Evolução Molecular , Técnicas de Inativação de Genes , Família Multigênica , Estresse Oxidativo , Fenótipo , Superóxido Dismutase/metabolismo
15.
J Food Biochem ; 43(4): e12796, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31353595

RESUMO

Rosa rugosa aqueous polyphenol (RAP) is a kind of polyphenol from Rosa rugosa flower tea. In this study, the antiaging activities of RAP were studied in the model organism Caenorhabditis elegans. UHPLC-HESI-MS/MS was employed to identify the specific phenolic profile, revealing that there were 23 types of phenolic compounds in RAP and that quercetin glycoside was the principal component. RAP increased the mean lifespan of C. elegans and enhanced the thermotolerance and resistance to oxidative stress of C. elegans in a concentration-dependent manner. Furthermore, RAP showed powerful antioxidant effects in vitro and strong protection against oxidative DNA damage. RAP significantly improved the levels of total superoxide dismutase and total antioxidant capacity of C. elegans. In conclusion, RAP has antiaging effects on C. elegans, which might be related to its powerful antioxidant effects both in vitro and in vivo. PRACTICAL APPLICATIONS: In recent years, chronic diseases associated with aging have had a profound impact on quality of life. Many healthy foods have antiaging properties, especially flower teas, such as those made from Rosa rugosa. Our results indicated that Rosa rugosa tea is good for health and that RAP could potentially be developed as a bioactive product that could be used to combat aging.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Rosa/química , Envelhecimento , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Flores/química , Estresse Oxidativo , Extratos Vegetais/química , Polifenóis/química , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Espectrometria de Massas em Tandem
16.
Artif Cells Nanomed Biotechnol ; 47(1): 1758-1765, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31062616

RESUMO

Salidroside (Sal) exerted widely pharmacological effects in multitudinous diseases had been certified. The actual study clarified the protective activity of Sal in H2O2-injured human trabecular meshwork (HTM) cells. HTM cells were disposed with H2O2 to construct an oxidative damage model in vitro. Then, Sal was utilized to administrate HTM cells, and cell viability, apoptosis, apoptosis-interrelated proteins and ROS production were appraised using CCK-8, flow cytometry, western blot and DCFH-DA staining. MiR-27a inhibitor and its control were transfected into HTM cells, and the influences of miR-27a inhibition in HTM cells stimulated with H2O2 and Sal were detected. PI3K/AKT and Wnt/ß-catenin pathways were ultimately investigated to uncover the underlying mechanism. We found that H2O2 evoked HTM cells oxidative damage, as evidenced by repressing cell viability, inducing apoptosis, activating cleaved-caspase-3/-9 expression and increasing ROS production. Sal significantly lightened H2O2-evoked oxidative damage in HTM cells. Additionally, miR-27a was up-regulated by Sal, and miR-27a suppression significantly reversed the protective effect of Sal on H2O2-injured HTM cells. Finally, Sal activated PI3K/AKT and Wnt/ß-catenin pathways through enhancement of miR-27a in H2O2-injured HTM cells. In conclusion, these discoveries suggested that Sal could protect HTM cells against H2O2-evoked oxidative damage by activating PI3K/AKT and Wnt/ß-catenin pathways through enhancement of miR-27a. Highlights H2O2 evokes HTM cells oxidative damage; Sal relieves H2O2-induced oxidative damage in HTM cells; Sal enhances miR-27a expression in H2O2-injured HTM cells; Repressed miR-27a reverses the protective impacts of Sal on H2O2-injured HTM cells; Sal activates PI3K/AKT and Wnt/ß-catenin pathways by increasing miR-27a.


Assuntos
Glucosídeos/farmacologia , Peróxido de Hidrogênio/farmacologia , MicroRNAs/genética , Fenóis/farmacologia , Malha Trabecular/citologia , Malha Trabecular/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Malha Trabecular/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos
17.
Front Pharmacol ; 10: 225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30983994

RESUMO

The pharmacokinetic profile of a drug can be different when delivered as a nanosuspension compared with a true solution, which may in turn affect the therapeutic effect of the drug. The goal of this study was to prepare itraconazole nanosuspensions (ITZ-Nanos) stabilized by an amphipathic polymer, polyethylene glycol-poly (benzyl aspartic acid ester) (PEG-PBLA), by the precipitation-homogenization, and study the pharmacokinetic profile of the ITZ-Nanos. The particle size and morphology of nanosuspensions were determined by Zetasizer and field emission scanning electron microscope (SEM), respectively. The dissolution profile was evaluated using a paddle method according to Chinese Pharmacopoeia 2015. The level of ITZ in plasma and tissues was measured by a HPLC method. The optimized ITZ-Nanos had an average particle size of 268.1 ± 6.5 nm and the particles were in a rectangular form. The dissolution profile of ITZ-Nanos was similar to that of commercial ITZ injections, with nearly 90% ITZ released in the first 5 min. The ITZ-Nanos displayed different pharmacokinetic properties compared with the commercial ITZ injections, including a decreased initial drug concentration, increased plasma half-life and mean residence time (MRT), and increased concentration in the liver, lung, and spleen. The ITZ-Nanos can change the in vivo distribution of ITZ and result in passive targeting to the organs with mononuclear phagocyte systems (MPS).

18.
Molecules ; 24(4)2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30769776

RESUMO

Glutinous rice-based foods have a long history are consumed worldwide. They are also in great demand for the pursuit of novel sensory and natural health benefits. In this study, we developed a novel fermented glutinous rice product with the supplementation of Fu brick tea. Using in vitro antioxidant evaluation and phenolic compounds analysis, fermentation with Fu brick tea increased the total phenolic content and enhanced the antioxidant activity of glutinous rice, including scavenging of 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical, and hydroxyl radical, ferric-reducing antioxidant power, and ferric ion reducing power and iron chelating capability. Besides, compared with traditional fermented glutinous rice, this novel functional food exhibited a stronger activity for protecting DNA against hydroxyl radical-induced oxidation damage. Quantitative analysis by HPLC identified 14 compounds covering catechins and phenolic acids, which were considered to be positively related to the enhanced antioxidant capability. Furthermore, we found that 80% ethanol was a suitable extract solvent compared with water, because of its higher extraction efficiency and stronger functional activities. Our results suggested that this novel fermented glutinous rice could serve as a nutraceutical food/ingredient with special sensory and functional activities.


Assuntos
Antioxidantes/química , Quelantes de Ferro/química , Oryza/química , Fenóis/química , Benzotiazóis/química , Compostos de Bifenilo/química , Catecóis/química , China , Cromatografia Líquida de Alta Pressão , Dano ao DNA/efeitos dos fármacos , Fermentação , Sequestradores de Radicais Livres/química , Humanos , Radical Hidroxila/química , Oxirredução , Picratos/química , Ácidos Sulfônicos/química , Triterpenos/química
19.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1074-1075: 39-45, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29331742

RESUMO

This paper described a reliable and simple method for the selective determination of MQCA in animal tissues using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A highly targeted immunoaffinity column was used for sample purification after enzymatic hydrolysis. The purified extracts were analyzed by reversed-phase HPLC-MS/MS in positive ESI and multiple reaction monitoring mode. The calibration curves showed good linearity with correlation coefficient (r2) larger than 0.995. The average recoveries at the spiked levels of 0.5, 2.0 and 20µgkg-1 were 90.2% to 103.5% with intra-day and inter-day relatives standard deviations (RSD, n=6) ranging from 1.8% to 6.7% and 3.5% to 7.6% respectively. The limit of quantification (LOQ) was 0.5µgkg-1, which can fulfil the maximum residue level (MRL) of 4.0µgkg-1 stipulated by the Agricultural Minister of China and the requirement of the confirmatory criteria according to the European Commission Decision 2002/657/EC. The method is sensitive, accurate, convenient and rapid, and has been successfully applied in real samples.


Assuntos
Cromatografia de Afinidade/métodos , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Quinoxalinas/análise , Quinoxalinas/isolamento & purificação , Espectrometria de Massas em Tandem/métodos , Animais , Galinhas , Estabilidade de Medicamentos , Peixes , Modelos Lineares , Carne/análise , Quinoxalinas/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...