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Streptomyces genus produces a large number of antibiotics, which are always synthesized by specific biosynthetic gene clusters (BGCs). To resist autotoxicity, transporters encoded by genes located within BGC occasionally pump antibiotic along with transporter encoded by gene located outside BGC. Daunorubicin is an anthracycline antibiotic biosynthesized by Streptomyces species, playing a crucial role in the treatment of leukaemia. In existing studies, only one two-component ATP-binding cassette (ABC) transporter, encoded by drrA1-drrB1 (abbreviated as drrAB1) and located within the daunorubicin BGC, has been proven to extrude daunorubicin. In this work, two other two-component ABC transporters, encoded by drrAB2 and drrAB3 and located outside the cluster, were found to play the complementary role in daunorubicin efflux in S. coeruleorubidus. Disruption of three drrABs resulted in a 94% decrease in daunorubicin production. Furthermore, drrAB2 is regulated by the TetR family regulator DrrR1, responding to the intracellular accumulation of daunorubicin and suggesting its role in stress response and self-resistance. Although the homologues of DrrAB1 are only found in three anthracycline BGCs, the homologues of DrrAB2 and DrrAB3 are spread in many Streptomyces strains which do not contain any known anthracycline BGC. This indicates that DrrAB2 and DrrAB3 may recognize and extrude a broader range of substrates besides daunorubicin, thus playing a more extensive role in cellular detoxification.
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Transportadores de Cassetes de Ligação de ATP , Daunorrubicina , Streptomyces , Daunorrubicina/metabolismo , Streptomyces/metabolismo , Streptomyces/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Antibacterianos/metabolismo , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Transporte Biológico , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genéticaRESUMO
The form of soil nitrogen input significantly affects soil CO2 emission. As a new form of nitrogen input, biochar-loaded ammonia nitrogen not only reduces the input of chemical nitrogen fertilizer in farmland but also reduces the cost of environmental treatment. It is of great significance to promote the zero growth of national chemical fertilizer, the prevention and control of farmland non-point source pollution, and the realization of the national goal of "carbon peak" and "carbon neutralization." Through an indoor culture experiment, the effects of different nitrogen input forms on soil carbon emission, enzyme activity, and microbial community were studied through four treatments:no fertilization (CK), single application of chemical nitrogen fertilizer (CF), biochar combined application of chemical nitrogen fertilizer (BF), and biochar-loaded ammonia nitrogen (BN). The results showed that compared with that in CF, BF significantly increased cumulative carbon emissions (66.24 %), whereas BN had no significant difference. It is worth noting that the cumulative carbon emissions were significantly reduced by 35.28 % compared with that in BF and BN. Compared with those in CF and BF, the activities of ß-glucosidase, peroxidase, and polyphenol oxidase treated with BN significantly increased by 20.25 % and 5.20 %, respectively. Compared with that in CF, the BF treatment increased microbial community richness and community diversity, whereas the BN treatment decreased microbial community richness. Compared with that in BF, the relative abundance of Proteobacteria decreased by 11.16 %, and the relative abundance of Actinobacteria and Bacteroidota increased by 8.12 % and 5.83 %, respectively, in which xylosidase activity was the most important soil factor affecting microbial community structure. The relative abundance of Chloroflexi was significantly correlated with cellobiose hydrolase activity, and the relative abundance of Gemmatimonadetes was significantly correlated with ß-glucosidase activity. There was a very significant correlation between the relative abundance of Proteobacteria and cumulative carbon emissions. To summarize, compared with those under biochar combined with chemical nitrogen fertilizer, biochar loaded with ammonia nitrogen significantly reduced cumulative carbon emissions, and its emission reduction effect was better. The results of this study will be beneficial to the landing of the national "double carbon strategy," the healthy development of the biological natural gas industry, the construction of the national green cultivation circular agriculture system, and the realization of the national zero growth strategy of chemical fertilizer.
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Amônia , Carbono , Carvão Vegetal , Fertilizantes , Nitrogênio , Microbiologia do Solo , Solo , Carvão Vegetal/química , Solo/química , Microbiota/efeitos dos fármacos , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/efeitos dos fármacos , Dióxido de Carbono/análiseRESUMO
As a recently discovered waste removal system in the brain, cerebral lymphatic system is thought to play an important role in regulating the homeostasis of the central nervous system. Currently, more and more attention is being focused on the cerebral lymphatic system. Further understanding of the structural and functional characteristics of cerebral lymphatic system is essential to better understand the pathogenesis of diseases and to explore therapeutic approaches. In this review, we summarize the structural components and functional characteristics of cerebral lymphatic system. More importantly, it is closely associated with peripheral system diseases in the gastrointestinal tract, liver, and kidney. However, there is still a gap in the study of the cerebral lymphatic system. However, we believe that it is a critical mediator of the interactions between the central nervous system and the peripheral system.
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Sistema Nervoso Central , Sistema Linfático , Encéfalo/fisiologia , HomeostaseRESUMO
Dichloroacetate (DCA) is an investigational drug used to treat lactic acidosis and malignant tumours. It works by inhibiting pyruvate dehydrogenase kinase and increasing the rate of glucose oxidation. Some studies have documented the neuroprotective benefits of DCA. By reviewing these studies, this paper shows that DCA has multiple pharmacological activities, including regulating metabolism, ameliorating oxidative stress, attenuating neuroinflammation, inhibiting apoptosis, decreasing autophagy, protecting the bloodâbrain barrier, improving the function of endothelial progenitor cells, improving mitochondrial dynamics, and decreasing amyloid ß-protein. In addition, DCA inhibits the enzyme that metabolizes it, which leads to peripheral neurotoxicity due to drug accumulation that may be solved by individualized drug delivery and nanovesicle delivery. In summary, in this review, we analyse the mechanisms of neuroprotection by DCA in different diseases and discuss the causes of and solutions to its adverse effects.
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Doenças Metabólicas , Neoplasias , Doenças do Sistema Nervoso , Fármacos Neuroprotetores , Humanos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Peptídeos beta-Amiloides , Neoplasias/tratamento farmacológicoRESUMO
Microplastics (MPs, <5 mm) are enriched in paddy ecosystems as emerging environmental pollutants. Biochar (BC) is a controversial recalcitrant carbon product that poses potential environmental risks. The presence of these two exogenous organic substances has been demonstrated to have impacts on soil nitrogen cycling and crop production. However, the after-effects of MPs and BC on soil ammonia (NH3) volatilization and rice yield after field aging remain unexplored. In this study, two common MPs, including polyethylene (PE) and polyacrylonitrile (PAN), and BC were selected for rice growing season observations to study the impacts on soil NH3 volatilization and rice yield after field aging. The results showed that the reduction of cumulative soil NH3 losses by MPs was around 45% after one-year field aging, which was within the range of 40-57% in the previous rice season. Abatement of NH3 volatilization by MPs mainly occurred in basal fertilization and was related to floodwater pH. Besides, the reduction rate of NH3 volatilization by BC and MPs + BC was enhanced after field aging (63% and 50-57%) compared to that in the previous rice season (5% and 11-19%), with the abatement process occurring in the first supplementary fertilization. There was a significant positive correlation between cumulative NH3 volatilization and soil urease activity. Notably, field aging removed the positive effect of MPs and MPs + BC in reducing yield-scale NH3 losses in the previous rice season (â¼62%). Furthermore, despite BC affecting rice yield insignificantly after field aging, the presence of MPs led to a significant 17-19% reduction in rice yield. Our findings reveal that differences in the after-effects of BC and MPs in field aging emerge, where the negative impacts of MPs on soil NH3 abatement and crop yield are progressively becoming apparent and should be taken into serious consideration.
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Oryza , Solo , Solo/química , Oryza/química , Amônia/análise , Microplásticos , Plásticos , Volatilização , Ecossistema , Nitrogênio/análise , Fertilizantes/análise , AgriculturaRESUMO
Background: Nonobvious early symptoms are a prominent characteristic of pancreatic cancer, resulting in only 20% of patients having resectable tumors at the time of diagnosis. The optimal management of unresectable advanced pancreatic cancer (UAPC) remains an open research question. In this study, the tumors shrank significantly after PD-1 antibody combined with chemotherapy in two UAPC patients, and both have achieved R0 (pathologically negative margin) resection and survival to date. Case presentation: Case 1: A 53-year-old man was diagnosed with pancreatic adenocarcinoma (Stage III). He received six cycles of PD-1 antibody plus chemotherapy as the first-line treatment. The tumor was reduced from 11.8×8.8 cm to "0" (the pancreatic head was normal as shown by enhanced computed tomography, ECT) after preoperative neoadjuvant therapy (PNT) and the adverse effects were tolerable. The patient underwent radical surgery and achieved R0 resection. Case 2: A 43-year-old man diagnosed with pancreatic adenocarcinoma with liver metastasis (Stage IV) received three cycles of PD-1 antibody combined with chemotherapy. The tumor was reduced from 5.2×3.9 cm to 2.4×2.3 cm with no side effects. The patient also underwent radical surgery and achieved R0 resection. Conclusion: PD-1 antibody plus a chemotherapy regimen resulted in a surprising curative effect and safety in two patients with UAPC, which may portend an improvement in pancreatic carcinoma treatment. We may have a way for UAPC patients to obtain radical treatment and gain long-term survival. Two PD-L1 positive UAPC patients with microsatellite stability (MSS) enlighten us to have a more comprehensive understanding of the prediction of immunotherapy.
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Adenocarcinoma , Neoplasias Pancreáticas , Adenocarcinoma/tratamento farmacológico , Adulto , Antígeno B7-H1 , Humanos , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Neoplasias Pancreáticas/tratamento farmacológico , Receptor de Morte Celular Programada 1 , Neoplasias PancreáticasRESUMO
To improve tobacco leaf quality, excessive K2SO4 fertilizers were applied to soils in major tobacco-planting areas in China. However, the effects of K2SO4 application on soil microbial community and functions are still unclear. An eight-year field experiment with three kinds of K2SO4 amounts (low amount, K2O 82.57 kg hm-2, LK; moderate amount, K2O 165.07 kg hm-2, MK; high amount, K2O 247.58 kg hm-2, HK) was established to assess the effects of K2SO4 application on the chemical and bacterial characteristics of tobacco-planting soil using 16S rRNA gene and metagenomic sequencing approaches. Results showed that HK led to lower pH and higher nitrogen (N), potassium (K), sulfur(S) and organic matter contents of the soil than LK. The bacterial community composition of HK was significantly different from those of MK and LK, while these of MK and LK were similar. Compared to LK, HK increased the relative abundance of predicted copiotrophic groups (e.g. Burkholderiaceae, Rhodospirillaceae families and Ellin6067 genus) and potentially beneficial bacteria (e.g. Gemmatimonadetes phylum and Bacillus genus) associated with pathogens and heavy metal resistance, N fixation, dissolution of phosphorus and K. While some oligotrophic taxa (e.g. Acidobacteria phylum) related to carbon, N metabolism exhibited adverse responses to HK. Metagenomic analysis suggested that the improvement of pathways related to carbohydrate metabolism and genetic information processing by HK might be the self-protection mechanism of microorganisms against environmental stress. Besides, the redundancy analysis and variation partitioning analysis showed that soil pH, available K and S were the primary soil factors in shifting the bacterial community and KEGG pathways. This study provides a clear understanding of the responses of soil microbial communities and potential functions to excessive application of K2SO4 in tobacco-planting soil.
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Streptomyces is well known for synthesis of many biologically active secondary metabolites, such as polyketides and non-ribosomal peptides. Understanding the coupling mechanisms of primary and secondary metabolism can help develop strategies to improve secondary metabolite production in Streptomyces. In this work, Streptomyces albus ZD11, an oil-preferring industrial Streptomyces strain, was proved to have a remarkable capability to generate abundant acyl-CoA precursors for salinomycin biosynthesis with the aid of its enhanced ß-oxidation pathway. It was found that the salinomycin biosynthetic gene cluster contains a predicted 3-hydroxyacyl-CoA dehydrogenase (FadB3), which is the third enzyme of ß-oxidation cycle. Deletion of fadB3 significantly reduced the production of salinomycin. A variety of experimental evidences showed that FadB3 was mainly involved in the ß-oxidation pathway rather than ethylmalonyl-CoA biosynthesis and played a very important role in regulating the rate of ß-oxidation in S. albus ZD11. Our findings elucidate an interesting coupling mechanism by which a PKS biosynthetic gene cluster could regulate the ß-oxidation pathway by carrying ß-oxidation genes, enabling Streptomyces to efficiently synthesize target polyketides and economically utilize environmental nutrients.
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3-Hidroxiacil-CoA Desidrogenase , Piranos , Streptomyces , 3-Hidroxiacil-CoA Desidrogenase/genética , 3-Hidroxiacil-CoA Desidrogenase/metabolismo , Família Multigênica , Policetídeos/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Piranos/metabolismoRESUMO
In varicose veins, abnormal phenotypic transition and inflammatory response is commonly found in venous smooth muscle cells (VSMCs). We aimed to explore the potential role and mechanism of NLRC5 exerted on VSMCs phenotypic transition and inflammation. NLRC5 expression was detected in varicose veins and platelet-derived growth factor (PDGF)-induced VSMCs by RT-qPCR and Western bolt assays. A loss-of-function assay was performed to evaluate the effects of NLRC5 knockdown on VSMC proliferation, migration, and phenotypic transition. ELISA was used to detect the contents of pro-inflammatory cytokines in the supernatant. The modulation of NLRC5 on TLR4 expression and Wnt/ß-catenin signaling was also evaluated. We found that the expressions of NLRC5 in varicose veins and PDGF-induced VSMCs were upregulated. NLRC5 knockdown inhibited VSMC proliferation and migration. Extracellular matrix transformation was blocked by downregulating NLRC5 with increasing SM-22α expression and MMP-1/TIMP-1 ratio, as well as decreasing OPN and collagen I expressions. Besides, NLRC5 silencing reduced the contents of inflammatory cytokines. Furthermore, we found that NLRC5 regulated TLR4 expression, as well as subsequently activation of Wnt/ß-catenin pathway and nuclear translocation of ß-catenin, which was involved in NLRC5-mediated phenotypic transition and inflammatory in VSMCs. In conclusion, silencing NLRC5 depressed VSMCs' phenotypic transition and inflammation by modulating Wnt/ß-catenin pathway via TLR4. This may provide a theoretical basis for treatment of varicose veins.
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Varizes , beta Catenina , Movimento Celular , Proliferação de Células , Citocinas/metabolismo , Humanos , Inflamação/genética , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Varizes/genética , beta Catenina/genética , beta Catenina/metabolismoRESUMO
Preeclampsia is an idiopathic disease of pregnancy, which seriously endangers the life of both the mother and the infant. The pathogenesis of preeclampsia has not been fully elucidated, although it is generally considered to be associated with abnormal lipid metabolism during pregnancy. Comparative gene identification-58 (CGI-58) and lipoprotein lipase (LPL) are involved in the first step of triglyceride hydrolysis and serve an important role in lipid transport in the placenta. The present study aimed therefore to investigate the association between CGI-58 and LPL in the placentas of patients with or without preeclampsia and to evaluate blood lipid levels. The patient cohort was divided into two groups, pregnant women with preeclampsia and normal pregnant women (control). According to biochemical analyses, reverse transcription-quantitative PCR, immunohistochemistry analysis and western blotting, the expression of CGI-58 and LPL in the placenta was detected, the blood lipid levels were evaluated and other clinical data were collected. Compared with the control group, triglycerides (TGs), low density lipoprotein-cholesterol (LDL-C), apolipoprotein B (ApoB) and atherosclerotic index (AI) were significantly higher in the preeclampsia group, whereas high density lipoprotein-cholesterol (HDL-C) and apolipoprotein A (ApoA) were significantly lower (P<0.05). Furthermore, the expression levels of CGI-58 and LPL in the placental tissue of the preeclampsia group was significantly lower than that of the control group (P<0.05). Linear correlation analysis demonstrated that there was a positive association between CGI-58 and LPL (r=0.602; P<0.05), that CGI-58 was positively associated with HDL-C (r=0.63; P<0.01) but negatively associated with TG and ApoB (r=0.840; P<0.01; and r=0.514; P<0.05, respectively), that LPL was positively associated with HDL-C (r=0.524; P<0.01) but negatively associated with TG and AI (r=0.659; P<0.01; and r=0.496; P<0.01, respectively). These results suggested that the expression of CGI-58 and LPL in the placenta was associated with the pathogenesis of preeclampsia and maternal lipids and the risk of preeclampsia was increased with decreasing expression levels of CGI-58 and LPL. Hence, CGI-58 and LPL may be used as important indicators for the diagnosis of preeclampsia and for the prevention of preeclampsia in pregnant women.
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The genus Streptomyces is intensively studied due to its excellent ability to produce secondary metabolites with diverse bioactivities. In particular, adequate precursors of secondary metabolites as well as sophisticated post modification systems make some high-yield industrial strains of Streptomyces the promising chassis for the heterologous production of natural products. However, lack of efficient genetic tools for the manipulation of industrial strains, especially the episomal vector independent tools suitable for large DNA fragment deletion, makes it difficult to remold the metabolic pathways and streamline the genomes in these strains. In this respect, we developed an efficient deletion system independent of the episomal vector for large DNA fragment deletion. Based on this system, four large segments of DNA, ranging in length from 10 kb to 200 kb, were knocked out successfully from three industrial Streptomyces strains without any marker left. Notably, compared to the classical deletion system used in Streptomyces, this deletion system takes about 25% less time in our cases. This work provides a very effective tool for further genetic engineering of the industrial Streptomyces.
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Engenharia Genética/métodos , Microbiologia Industrial/métodos , Streptomyces/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cromossomos Bacterianos/genética , DNA Bacteriano/genética , Família Multigênica/genética , Piperidonas/metabolismo , Deleção de Sequência , Streptomyces/metabolismoRESUMO
To safely and effectively transfer NH4+-N from eutrophic water to soil, biochar was applied to adsorb NH4+-N from wastewater, and this NH4+-N loaded biochar (N-BC) was subsequently used as a soil amendment. Understanding the influence of N-BC on N2O-N emission and NH3-N volatilization is important for both decreasing the application of chemical fertilizers and reducing gaseous nitrogen loss from soil. In this study, experiments were conducted in soil columns with four treatments, namely CK (no fertilizer), NPK (chemical fertilizer), N-BC+PK (NH4+-N loaded biochar+chemical fertilizer), and BC+NPK (biochar+chemical fertilizer). Compared to both the NPK and BC+NPK treatments, N-BC+PK significantly reduced the cumulative N2O-N emissions and NH3-N volatilization, as well as the total gaseous nitrogen loss from the soil (P<0.05). Relative to NPK and BC+NPK, cumulative N2O-N emissions decreased by 33.62% and 24.64%, cumulative NH3-N volatilization decreased 70.64% and 79.29%, and the cumulative total gaseous nitrogen loss decreased by 64.97% and 73.75%. In particular, BC+NPK significantly enhanced the cumulative NH3-N volatilization. Furthermore, the N2O-N emission flux and NH3-N volatilization rate were significantly positively correlated with the NH4+-N concentration, NO3--N concentration, and pH of soil (P<0.01). Overall, using NH4+-N loaded biochar can significantly decrease N2O-N emissions and NH3-N volatilization, relative to the traditional application combining biochar and chemical fertilizer. This research provides solid theoretical support and data for the application of NH4+-N loaded biochar in soil, to reduce gaseous nitrogen loss.
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Nitrogênio , Solo , Carvão Vegetal , Gases/análiseRESUMO
Remediating the agricultural soil polluted by cadmium (Cd) is a serious issue in China. Hydrochar showed its potential to purify Cd-contaminated water and improve Cd-contaminated soil due to its vast amounts of macro- and microporous structures. In this study, three concentration gradients of nitric acid (HNO3, mass fraction: 5%, 10%, 15%) were implemented to age pristine wheat straw hydrochar (N0-HC) aiming to improve surface physiochemical properties. Four HNO3-aging hydrochars named N0-HC, N5-HC, N10-HC, N15-HC were used to both remove Cd2+ from aqueous solution and improve soil properties. Results showed that HNO3-aging significantly improved the Cd2+ adsorption capacity by 1.9-9.9 folds compared to crude hydrochar due to the increased specific surface area (by 1.5-6.5 folds) and oxygen-containing functional group abundance (by 4.5-22.1%). Besides, initial solution pH of 8 or environmental temperature of 318.15 K performed the best Cd2+ adsorption capacity. Furthermore, the process of Cd2+ adsorption was fitted best to pseudo-second-order (R2 = 0.95) and Langmuir models (R2 = 0.98), respectively. Nanjing 46 (Oryza sativa L) and HNO3-aging hydrochars were furtherly applied into Cd-contaminated paddy soil to investigate the mitigation of Cd translation from soil to rice. N15-HC-1% (w/w) performed the best effect on reducing cadmium accumulation in various parts of rice plants. Overall, this research provided an approach to improve hydrochar capacity to remove Cd2+ from aqueous solution and mitigate Cd translation from soil to rice.
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Oryza , Poluentes do Solo , Adsorção , Cádmio/análise , Carvão Vegetal , Ácido Nítrico , Solo , Poluentes do Solo/análiseRESUMO
OBJECTIVE: The present study aimed to explore the function of sirtuin 2 (SIRT2) on cell proliferation, apoptosis, rat sarcoma virus (RAS)/ extracellular signal-regulated kinase (ERK) pathway in endometrial cancer (EC). METHODS: SIRT2 expression in human EC cell lines and human endometrial (uterine) epithelial cell (HEEC) line was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. SIRT2 knock-down and control knock-down plasmids were transfected into HEC1A cells, respectively; SIRT2 overexpression and control overexpression plasmids were transfected into Ishikawa cells, respectively. After transfection, SIRT2, HRas proto-oncogene, GTPase (HRAS) expressions were evaluated by RT-qPCR and western blot. ERK and phosphorylated ERK (pERK) expressions were evaluated by western blot. Meanwhile, cell proliferation and cell apoptosis were measured. RESULTS: Compared to normal HEEC cell line, SIRT2 mRNA and protein expressions were increased in most human EC cell lines (including HEC1A, RL952 and AN3CA), while were similar in Ishikawa cell line. In HEC1A cells, SIRT2 knock-down decreased cell proliferation but increased apoptosis. In Ishikawa cells, SIRT2 overexpression induced cell proliferation but inhibited apoptosis. For RAS/ERK pathway, SIRT2 knock-down reduced HRAS and inactivated pERK in HEC1A cells, whereas SIRT2 overexpression increased HRAS and activated pERK in Ishikawa cells, suggesting that SIRT2 was implicated in the regulation of RAS/ERK pathway in EC cells. CONCLUSION: SIRT2 contributes to the EC tumorigenesis, which appears as a potential therapeutic target.
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Neoplasias do Endométrio/etiologia , Sirtuína 2/genética , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Expressão Gênica , Humanos , Proto-Oncogene Mas , Interferência de RNA , RNA Interferente Pequeno/genética , Transdução de Sinais , Sirtuína 2/metabolismo , Proteínas ras/metabolismoRESUMO
In this work, the sensitivity zone of microstructure and temperature for precipitation-strengthened nickel-based superalloys, used for turbine applications in aero-engines, has been firstly established. Heat treatment experiments with different solution temperatures were carried out. The microstructure evolution and creep residual strain sensitivity, low cycle fatigue properties, and tensile properties are analyzed, and the essential reason for the fluctuation of the mechanical properties of nickel-based superalloys was revealed. The main results obtained are as follows: following subsolvus solution heat treatment with a temperature of 1020 °C, samples have a high primary γ'I phase content, which is beneficial to low creep residual strain. Above the supersolvus solution temperature of 1040 °C, the creep residual strain value and low cycle fatigue performance fluctuate significantly. The essential reason for the dramatic fluctuation of performance is the presence of γ' phases in different sizes and quantities, especially following the solution heat treatment in the temperature-sensitive zone of the γ'I phase, which is likely to cause huge fluctuations in the microstructure of tertiary γ'III phases. A zone of particular sensitivity in terms of temperature and microstructure for the γ'I phase is proposed. The range of suitable solution temperatures are discussed. In order to maintain stable mechanical properties without large fluctuations, the influence of the sensitivity within this temperature and microstructure zone on the γ' phase should be considered.
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Streptomyces is well known for biosynthesis of secondary metabolites with diverse bioactivities. Although oils have been employed as carbon sources to produce polyketide antibiotics for several industrial Streptomyces strains, the intrinsic correlation between oil utilization and high production of antibiotics still remains unclear. In this study, we investigated the correlation between oil metabolism and salinomycin biosynthesis in Streptomyces albus ZD11, which employs soybean oil as the main carbon source. Comparative genomic analysis revealed the enrichment of genes related to triacylglycerol (TAG) metabolism in S. albus ZD11. Transcriptomic profiling further confirmed the enhancement of TAG metabolism and acyl coenzyme A biosynthesis in S. albus ZD11. Multiple secreted lipases, which catalyze TAG hydrolysis, were seen to be working in a synergistic and complementary manner in aiding the efficient and stable hydrolyzation of TAGs. Together, our results suggest that enhanced TAG hydrolysis and fatty acid degradation contribute to the high efficiency of oil utilization in S. albus ZD11 in order to provide abundant carbon precursors for cell growth and salinomycin biosynthesis.IMPORTANCE In order to obtain high-level production of antibiotics, oils have been used as the main carbon source for some Streptomyces strains. Based on multiomics analysis, this study provides insight into the relationship between triacylglycerol (TAG) metabolism and antibiotic biosynthesis in S. albus ZD11, an oil-preferring industrial Streptomyces strain. Our investigation into TAG hydrolysis yielded further evidence that this strain utilizes complicated strategies enabling an efficient TAG metabolism. In addition, a novel secreted lipase was identified that exhibited highly hydrolytic activity for medium- and long-chain TAGs. Our findings represent a good start toward clarifying the complicated relationship between TAG catabolism and high-level antibiotic production in the industrial strains.
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Antibacterianos/biossíntese , Coccidiostáticos , Óleos/metabolismo , Piranos/metabolismo , Streptomyces/metabolismo , Triglicerídeos/metabolismoRESUMO
To promote the sustainable development of the liquor/ethanol industry and environment protection, alternative ways to dispose of anaerobic digestion residue (ADR) are urgently required. This research aims at studying the effects of different residence times (RTs) (30, 60 and 120 min) and heating rates (HR) (2.5, 5.0 and 10.0°C min-1) under 700°C on characteristics of ADR biochar as well as the optimization of ammonium (NH4+) adsorption. Results showed that, with the increasing RT and HR, the aromaticity as well as the content of fixed carbon and elemental carbon of ADR biochar increased, but the pyrolysis yield, volatile matter content, elemental hydrogen, oxygen and polarity decreased. Biochar prepared at 60 min and 5.0°C min-1 under 700°C presented the best development of orderly and honeycomb shape structures, highest specific surface area and maximal amount of NH4+ adsorption (3.15 mg N g-1). The multilayer heterogeneous adsorption process dominated the NH4+ adsorption behaviour. And the maximal amount of NH4+ adsorption was achieved with 4 g biochar L-1 at pH 11.0 along with the order of the competitive effect of K+ > Na+ > Ca2+ > Mg2+. Furthermore, NH4+ adsorption was exothermic. Thus, the present study demonstrated that ADR biochar has potential to adsorb NH4+ from NH4+ polluted water to meet environmental standards.
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Compostos de Amônio , Adsorção , Anaerobiose , Carvão Vegetal , PiróliseRESUMO
OBJECTIVES: The purpose of the present study was to investigate the expressions of DNA methyltransferase 1 (DNMT1) and cyclin A1 (CCNA1) protein and mRNA in the process of cervical carcinogenesis. METHODS: The specimens were separated into the following groups: control (n=30), low-grade squamous intraepithelial lesions (LSIL, n=30), high-grade squamous intraepithelial lesions (HSIL) and squamous cell cervical cancers (SCC, n=30). Immunohistochemical examination, Western blot and real-time quantitative PCR were used to investigate the protein and mRNA expressions of DNMT1 and CCNA1 in cervical tissues. RESULTS: We found that the positive expression rate and intensity of DNMT1 mRNA and protein gradually increased in the process of cervical carcinogenesis. However, the increase of the positive expression rate of DNMT1 mRNA and protein form the LSIL group to HSIL group was not significant (P>0.05). After cervical intraepithelial neoplasia (CIN), the positive expression rate and intensity of CCNA1 mRNA and protein significantly decreased with the aggravation of cervical lesions (P<0.05), and there was no significant difference between the LSIL and control groups (P>0.05). CONCLUSIONS: With the severity of cervical lesions, the expression of DNMT1 protein and mRNA increased gradually. The expression of CCNA1 protein and mRNA decreased gradually. The DNMT1 and CCNA1 expressions are associated with cervical lesions.
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Exploring functional information among various brain regions across time enables understanding of healthy aging process and holds great promise for age-related brain disease diagnosis. This paper proposed a method to explore fractal complexity of the resting-state functional magnetic resonance imaging (rs-fMRI) signal in the human brain across the adult lifespan using Hurst exponent (HE). We took advantage of the examined rs-fMRI data from 116 adults 19 to 85 years of age (44.3 ± 19.4 years, 49 females) from NKI/Rockland sample. Region-wise and voxel-wise analyses were performed to investigate the effects of age, gender, and their interaction on complexity. In region-wise analysis, we found that the healthy aging is accompanied by a loss of complexity in frontal and parietal lobe and increased complexity in insula, limbic, and temporal lobe. Meanwhile, differences in HE between genders were found to be significant in parietal lobe (p = 0.04, corrected). However, there was no interaction between gender and age. In voxel-wise analysis, the significant complexity decrease with aging was found in frontal and parietal lobe, and complexity increase was found in insula, limbic lobe, occipital lobe, and temporal lobe with aging. Meanwhile, differences in HE between genders were found to be significant in frontal, parietal, and limbic lobe. Furthermore, we found age and sex interaction in right parahippocampal gyrus (p = 0.04, corrected). Our findings reveal HE variations of the rs-fMRI signal across the human adult lifespan and show that HE may serve as a new parameter to assess healthy aging process.