RESUMO
Marine phycosphere hosts cross-kingdom algae-bacteria interactions playing a variety of crucial roles in aquatic ecosystems especially for the prevention and control of harmful algal blooms (HABs). During the investigation of structural composition of phycosphere microbiota (PM) of diverse marine HAB dinoflagellates, a Gram-negative, strictly aerobic, non-motile and rod-shaped bacterium designated LZ-17T was isolated from the phycosphere of highly toxic Alexandrium catenella LZT09. The 16S rRNA gene sequence analysis and the multilocus sequence analysis (MLSA) based on five protein-coding housekeeping genes (atpD, gyrB, mutL, topA and rpoD) indicated that strain LZ-17T was affiliated to the genus Maritimibacter within the family Rhodobacteraceae, and closely related to Maritimibacter alkaliphilus HTCC2654T (99.1%), 'Maritimibacter harenae' DP07T (97.9%) and M. lacisalsi X12M-4T (95.7%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain LZ-17T and the type strain of M. alkaliphilus were 96.9% and 74.7%. However, strain LZ-17T could be clearly distinguished from its closest by the phenotypical and phenotypical characteristics. Strain LZ-17T contained Q-10 as its major isoprenoid quinone, and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), C16:0 and C16:0 2-OH as the predominant fatty acids (>10%). The major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. The DNA G + C content was 64.3 mol%. Based on the polyphasic taxonomic characterization, strain LZ-17T represents a novel species of the genus Maritimibacter, for which the name Maritimibacter alexandrii sp. nov. is proposed, with the type strain LZ-17T (=CCTCC 2019005T = KCTC 72193T).
Assuntos
Dinoflagellida , Microbiota , Rhodobacteraceae , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNARESUMO
A new versatile actinobacterium designated as strain NJES-13 was isolated from the feces of the Antarctic emperor penguin. This new isolate was found to produce two active gephyromycin analogues and bioflocculanting exopolysaccharides (EPS) metabolites. Phylogenetic analysis based on pairwise comparison of 16S rRNA gene sequences showed that strain NJES-13 was closely related to Mobilicoccus pelagius Aji5-31T with a gene similarity of 95.9%, which was lower than the threshold value (98.65%) for novel species delineation. Additional phylogenomic calculations of the average nucleotide identity (ANI, 75.9-79.1%), average amino acid identity (AAI, 52.4-66.9%) and digital DNA-DNA hybridization (dDDH, 18.6-21.9%), along with the constructed phylogenomic tree based on the up-to-date bacterial core gene (UBCG) set from the bacterial genomes, unequivocally separated strain NJES-13 from its close relatives within the family Dermatophilaceae. Hence, it clearly indicated that strain NJES-13 represented a putative new actinobacterial species isolated from the gut microbiota of mammals inhabiting the Antarctic. The obtained complete genome of strain NJES-13 consisted of a circular 3.45 Mb chromosome with a DNA G+C content of 67.0 mol%. Furthering genome mining of strain NJES-13 showed the presence of five biosynthetic gene clusters (BGCs) including one type III PKS responsible for the biosynthesis of the core of gephyromycins, and a series of genes encoding for bacterial EPS biosynthesis. Thus, based on the combined phylogenetic and active metabolites characterization presented in this study, we confidently conclude that strain NJES-13 is a novel, fresh actinobacterial candidate to produce active gephyromycins and microbial bioflocculanting EPS, with potential pharmaceutical, environmental and biotechnological implications.
Assuntos
Actinobacteria/genética , Antraquinonas/metabolismo , Hidrocarbonetos Aromáticos com Pontes/metabolismo , Spheniscidae , Animais , Regiões Antárticas , Organismos Aquáticos , Técnicas de Tipagem Bacteriana , Fezes/microbiologia , Humanos , Filogenia , Fitoterapia , RNA Ribossômico 16S/genéticaRESUMO
A diet that is high in sugar and fat is a precursor to various chronic diseases, especially hyperlipidemia. Patients with hyperlipidemia have increased levels of plasma free fatty acids and an ectopic accumulation of lipids. The kidney is one of the main organs affected by this disease and, recently, there have been more studies conducted on renal injury caused by hyperlipidemia. The main pathological mechanism is closely related to renal lipotoxicity. However, in different kidney cells, the reaction mechanism varies due to the different affinities of the lipid receptors. At present, it is believed that in addition to lipotoxicity, hyperlipidemia induced-renal injury is also closely related to oxidative stress, endoplasmic reticulum stress, and inflammatory reactions, which are the result of multiple factors. Exercise plays an important role in the prevention of various chronic diseases and recently emerging researches indicated its positive effects to renal injury caused by hyperlipidemia. However, there are few studies summarizing the effects of exercise on this disease and the specific mechanisms need to be further explored. This article summarizes the mechanisms of hyperlipidemia induced-renal injury at the cellular level and discusses the ways in which exercise may regulate it. The results provide theoretical support and novel approaches for identifying the intervention target to treat hyperlipidemia induced-renal injury.
Assuntos
Dieta Hiperlipídica , Hiperlipidemias , Humanos , Dieta Hiperlipídica/efeitos adversos , Hiperlipidemias/etiologia , Rim , Estresse Oxidativo , Ácidos Graxos não Esterificados/metabolismoRESUMO
Background: Most esophageal cancer patients are diagnosed at an advanced stage when there are few effective treatments. Transarterial infusion chemotherapy is a local chemotherapy method wherein chemotherapeutic drugs are directly injected into tumor vessels. Methods: Transarterial infusion chemotherapy was performed on advanced esophageal cancer patients once a month, and each patient underwent 1-3 treatments. The clinical results, complications, and effectiveness rates of each treatment episode were recorded and analyzed. Results: Transarterial infusion chemotherapy was successfully performed in all patients, and no severe complications such as paraplegia or death were noted. Complete response, partial response, and stable disease were noted in 17.3% (13/75), 77.3% (58/75), and 5.3% (4/75) of cases after transarterial infusion chemotherapy, respectively. The total treatment efficacy (complete response + partial response) was 94.7%. All cases exhibited improvement in clinical stage, with a marked decrease in dysphagia. Subsequent treatments were administered to 13 patients, including radical radiation in 7 and chemotherapy in 6. During follow-up, death was caused by progressive carcinoma in 20, tumor-related pneumatic infection and respiratory failure in 11, and gastrointestinal hemorrhage in 17. The median survival time was 15 months and the 1-year survival rate was 58.1%. Conclusions: Transarterial infusion chemotherapy may be safely and effectively used for treatment of advanced esophageal cancer.
RESUMO
The present study aimed to define the tumor-suppressive role of microRNA-499 (miR-499) in lung cancer cells and its underlying mechanism. First, qRT-PCR analysis revealed poor expression of miR-499 in clinical samples and cell lines of lung cancer. Next, we performed loss- and gain-of-function experiments for the expression of miR-499 in lung cancer cells exposed to irradiation (IR) to determine the effect of miR-499 expression on cell viability and apoptosis as well as tumor growth. Results showed that overexpression of miR-499 inhibited cell viability, enhanced the radiosensitivity of lung cancer cells, and promoted cell apoptosis under IR. Furthermore, CK2α was verified to be a target of miR-499, and miR-499 was identified to repress p65 phosphorylation by downregulating CK2α expression, which ultimately diminished the survival rate of lung cancer cells under IR. Collectively, the key findings of the study illustrate the tumor-inhibiting function of miR-499 and confirmed that miR-499-mediated CK2α inhibition and altered p65 phosphorylation enhances the sensitivity of lung cancer cells to IR.
RESUMO
A novel crown ether functionalized ionic liquid (IL), 1-allyl-3-(6'-oxo-benzo-15-crown-5 hexyl) imidazolium hexafluorophosphate was synthesized and used as selective stationary phase to prepare task-specific IL-based solid phase microextraction (SPME) fibers by sol-gel method and free radical cross-linking technology. The underlying mechanism of the sol-gel reaction was proposed and the successful chemical bonding of the crown ether functionalized IL to the formed hybrid organic-inorganic copolymer coating was confirmed by FT-IR spectroscopy. The performance of this in situ created crown ether functionalized IL-based SPME fibers, was investigated in detail. The coating has porous surface structure, stable performance in high temperature (to 340 °C) and in different solutions (water, organic solvent, acid and alkali), and good coating preparation reproducibility. In contrast to the sol-gel derived 1-allyl-3-methyl imidazolium hexafluorophosphate-based coating prepared in our previous work with the identical procedure, the extraction performance of this newly developed sol-gel crown ether functionalized IL-based coating was superior for alcohols, phthalate esters, phenolic environmental estrogens, fatty acids and aromatic amines due to the introduction of benzo-15-crown-5 functional group in IL structure. Moreover, it was shown to provide higher or comparable extraction efficiencies for most analytes studied than did the commercial PDMS, PDMS/DVB and PA fibers.
Assuntos
Éteres de Coroa/química , Líquidos Iônicos/química , Microextração em Fase Sólida/métodos , Cromatografia Gasosa , Éteres de Coroa/síntese química , Dimetilpolisiloxanos/química , Ácidos Graxos/isolamento & purificação , Temperatura Alta , Imidazóis/química , Nylons/química , Transição de Fase , Reprodutibilidade dos Testes , Propriedades de SuperfícieRESUMO
A pot experiment with the soils from Yongzhou, Liuyang, and Sangzhi, the high-quality tobacco planting regions of Hunan Province, was conducted to study the effects of climate, soil, and their interaction on some neutral volatile aroma components in flue-cured tobacco leaves. The contents of test neutral volatile aroma components in the flue-cured tobacco leaves were of medium variation, and the variation intensity was decreased in the order of dihydroactinolide, damascenone, furfural, total megastigmatrienone, and beta-ionone. Climate, soil, and their interaction affected the neutral volatile aroma components in different degrees. The furfural content was most affected by climate, the damascenone content was most affected by climate and by soil, the total megastigmatrienone and beta-ionone contents were most affected by the interaction of soil and climate, while the dihydroactinolide content was less affected by soil, climate, and their interaction. The contribution of climate, soil, and their interaction to the contents of the five aroma components was 40.82%, 20.67%, and 38.51%, respectively. During different growth periods of tobacco, different climate factors had different effects on the neutral volatile aroma components. The rainfall, cloudiness, and mean air temperature at rooting stage, the diurnal temperature amplitude, sunshine time, and evaporation at vigorous growth stage, and the rainfall, evaporation, and mean air temperature at maturing stage were the top three climate factors affecting the contents of the neutral volatile aroma components in flue-tobacco leaves. For the soil factors, the available potassium, available phosphorus, and pH were the top three factors affecting the contents of the five components.