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Citrin deficiency (CD) is an inborn error of metabolism caused by loss-of-function of the mitochondrial aspartate/glutamate transporter, CITRIN, which is involved in both the urea cycle and malate-aspartate shuttle. Patients with CD develop hepatosteatosis and hyperammonemia but there is no effective therapy for CD. Currently, there are no animal models that faithfully recapitulate the human CD phenotype. Accordingly, we generated a CITRIN knockout HepG2 cell line using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 genome editing technology to study metabolic and cell signaling defects in CD. CITRIN KO cells showed increased ammonia accumulation, higher cytosolic ratio of reduced versus oxidized form of nicotinamide adenine dinucleotide (NAD) and reduced glycolysis. Surprisingly, these cells showed impaired fatty acid metabolism and mitochondrial activity. CITRIN KO cells also displayed increased cholesterol and bile acid metabolism resembling those observed in CD patients. Remarkably, normalizing cytosolic NADH:NAD+ ratio by nicotinamide riboside increased glycolysis and fatty acid oxidation but had no effect on the hyperammonemia suggesting the urea cycle defect was independent of the aspartate/malate shuttle defect of CD. The correction of glycolysis and fatty acid metabolism defects in CITRIN KO cells by reducing cytoplasmic NADH:NAD+ levels suggests this may be a novel strategy to treat some of the metabolic defects of CD and other mitochondrial diseases.
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Citrulinemia , Hiperamonemia , Humanos , Citrulinemia/genética , Citrulinemia/metabolismo , NAD/metabolismo , Malatos , Ácido Aspártico/metabolismo , Hiperamonemia/genética , Proteínas de Transporte da Membrana Mitocondrial/genética , Hepatócitos/metabolismo , Glicólise , Ureia/metabolismo , Ácidos GraxosRESUMO
Mimicry is the phenomenon in which one species (the mimic) closely resembles another (the model), enhancing its own fitness by deceiving a third party into interacting with it as if it were the model. In plants, mimicry is used primarily to gain fitness by withholding rewards from mutualists or deterring herbivores cost-effectively. While extensive work has been documented on putative defence mimicry, limited investigation has been conducted in the field of chemical mimicry. In this study, we used field experiments, chemical analyses, behavioural assays, and electrophysiology, to test the hypothesis that the birthwort Aristolochia delavayi employs chemical mimicry by releasing leaf scent that closely resembles stink bug defensive compounds and repels vertebrate herbivores. We show that A. delavayi leaf scent is chemically and functionally similar to the generalized defensive volatiles of stink bugs and that the scent effectively deters vertebrate herbivores, likely through the activation of TRPA1 channels via (E)-2-alkenal compounds. This study provides an unequivocal example of chemical mimicry in plants, revealing intricate dynamics between plants and vertebrate herbivores. Our study underscores the potency of chemical volatiles in countering vertebrate herbivory, urging further research to uncover their potentially underestimated importance.
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Aristolochia , Heterópteros , Animais , Herbivoria , Aristolochia/química , Aristolochia/fisiologia , Heterópteros/fisiologia , Vertebrados , PlantasRESUMO
The East Palestine, Ohio train derailment released toxic vinyl chloride (VC) and butyl acrylate (BA), which entered the watershed. Streambed sediment, surface water, and private well water samples were collected 128 and 276 days postaccident to assess the natural attenuation potential of VC and BA by quantifying biodegradation biomarker genes and conducting microcosm treatability studies. qPCR detected the aerobic VC degradation biomarkers etnC in â¼40% and etnE in â¼27% of sediments collected in both sampling campaigns in abundances reaching 105 gene copies g-1. The 16S rRNA genes of organohalide-respiring Dehalococcoides and Dehalogenimonas were, respectively, detected in 50 and 64% of sediment samples collected 128 days postaccident and in 63 and 88% of sediment samples collected 276 days postaccident, in abundances reaching 107 cells g-1. Elevated detection frequencies of VC degradation biomarker genes were measured immediately downstream of the accident site (i.e., Sulphur Run). Aerobic VC degradation occurred in all sediment microcosms and coincided with increases of etnC/etnE genes and Mycobacterium, a genus comprising aerobic VC degraders. The conversion of VC to ethene and an increased abundance of VC reductive dechlorination biomarker genes were observed in microcosms established with sediments collected from Sulphur Run. All anoxic microcosms rapidly degraded BA to innocuous products with intermediate formation of n-butanol and acrylate. The results indicate that microbiomes in the East Palestine watershed have natural attenuation capacity for VC and BA. Recommendations are made to improve first-response actions in future contaminant release accidents of this magnitude.
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Cloreto de Vinil , Cloreto de Vinil/metabolismo , Ohio , Acrilatos , Biodegradação Ambiental , Poluentes Químicos da Água , RNA Ribossômico 16SRESUMO
BACKGROUND: Moyamoya disease (MMD) is a chronic ischemic cerebrovascular disease. Collateral circulation in MMD has emerged as a research focus. Our aims were to assess the impact of anastomoses between the anterior and posterior circulations on the prognosis of MMD patients. METHODS: We reviewed the preoperative digital subtraction angiography images of patients with MMD who underwent revascularization surgery at our hospital between March 2014 and May 2020 and divided the patients into two groups: those with anastomoses (PtoA group) and those without anastomoses (non-PtoA group). The differences in follow-up (more than 6 months) collateral vessel establishment (Matsushima grade) and the modified Rankin Scale (mRS) were compared between the two groups as well as between the patients with different degrees of anastomoses. The early complications following revascularization were also compared between the two groups. RESULTS: This study included 104 patients with MMD, of which 38 were non-PtoA and 66 were PtoA. There were no significant differences in Matsushima score (P = 0.252) and mRS score (P = 0.066) between the two groups. In addition, Matsushima score (P = 0.243) and mRS score (P = 0.360) did not differ significantly between patients with different degrees of anastomoses. However, the non-PtoA group had a significantly higher rate of cerebral hyperperfusion syndrome (CHS) than the PtoA group (34.2% vs 16.7%, P = 0.041). CONCLUSION: MMD patients without anastomoses between anterior and posterior circulations preoperatively should be vigilant of the occurrence of CHS in the early stages after revascularization.
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Revascularização Cerebral , Circulação Colateral , Doença de Moyamoya , Humanos , Doença de Moyamoya/cirurgia , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/fisiopatologia , Feminino , Masculino , Adulto , Revascularização Cerebral/métodos , Prognóstico , Pessoa de Meia-Idade , Circulação Colateral/fisiologia , Estudos Retrospectivos , Angiografia Digital , Adolescente , Adulto Jovem , Criança , Circulação Cerebrovascular/fisiologiaRESUMO
BACKGROUND: Mild cognitive impairment has received widespread attention as a high-risk population for Alzheimer's disease, and many studies have developed or validated predictive models to assess it. However, the performance of the model development remains unknown. OBJECTIVE: The objective of this review was to provide an overview of prediction models for the risk of Alzheimer's disease dementia in older adults with mild cognitive impairment. METHOD: PubMed, EMBASE, Web of Science, and MEDLINE were systematically searched up to October 19, 2023. We included cohort studies in which risk prediction models for Alzheimer's disease dementia in older adults with mild cognitive impairment were developed or validated. The Predictive Model Risk of Bias Assessment Tool (PROBAST) was employed to assess model bias and applicability. Random-effects models combined model AUCs and calculated (approximate) 95% prediction intervals for estimations. Heterogeneity across studies was evaluated using the I2 statistic, and subgroup analyses were conducted to investigate sources of heterogeneity. Additionally, funnel plot analysis was utilized to identify publication bias. RESULTS: The analysis included 16 studies involving 9290 participants. Frequency analysis of predictors showed that 14 appeared at least twice and more, with age, functional activities questionnaire, and Mini-mental State Examination scores of cognitive functioning being the most common predictors. From the studies, only two models were externally validated. Eleven studies ultimately used machine learning, and four used traditional modelling methods. However, we found that in many of the studies, there were problems with insufficient sample sizes, missing important methodological information, lack of model presentation, and all of the models were rated as having a high or unclear risk of bias. The average AUC of the 15 best-developed predictive models was 0.87 (95% CI: 0.83, 0.90). DISCUSSION: Most published predictive modelling studies are deficient in rigour, resulting in a high risk of bias. Upcoming research should concentrate on enhancing methodological rigour and conducting external validation of models predicting Alzheimer's disease dementia. We also emphasize the importance of following the scientific method and transparent reporting to improve the accuracy, generalizability and reproducibility of study results. REGISTRATION: This systematic review was registered in PROSPERO (Registration ID: CRD42023468780).
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Doença de Alzheimer , Disfunção Cognitiva , Humanos , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Idoso , Medição de Risco/métodosRESUMO
Natural aerosols in pristine regions form the baseline used to evaluate the impact of anthropogenic aerosols on climate. Sea spray aerosol (SSA) is a major component of natural aerosols. Despite its importance, the abundance of SSA is poorly constrained. It is generally accepted that wind-driven wave breaking is the principle governing SSA production. This mechanism alone, however, is insufficient to explain the variability of SSA concentration at given wind speed. The role of other parameters, such as sea surface temperature (SST), remains controversial. Here, we show that higher SST promotes SSA mass generation at a wide range of wind speed levels over the remote Pacific and Atlantic Oceans, in addition to demonstrating the wind-driven SSA production mechanism. The results are from a global scale dataset of airborne SSA measurements at 150 to 200 m above the ocean surface during the NASA Atmospheric Tomography Mission. Statistical analysis suggests that accounting for SST greatly enhances the predictability of the observed SSA concentration compared to using wind speed alone. Our results support implementing SST into SSA source functions in global models to better understand the atmospheric burdens of SSA.
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OBJECTIVE: The objective of this paper was to assess the risk factors for persistent headache attributed to retrosigmoid craniotomy. Furthermore, we evaluated the role of the 3D computed tomography venography(CTV) image-guided technique in reducing the incidence of persistent headache. METHOD: The study encompassed patients with trigeminal neuralgia who underwent microvascular decompression. Patients were categorized into two groups based on the use of 3D CTV in surgical planning. Factors related to craniotomy and postoperative complications were analyzed between the two groups. Binary logistic regression analysis was conducted to identify risk factors for persistent headache attributed to craniotomy. RESULT: The inclusion criteria yielded 48 patients who underwent craniotomy with 3D CTV image guidance (the image-guided group) and 69 patients who did not use this technique (the control group). The image-guided group experienced significantly shorter craniotomy durations (27.9 ± 4.7 vs. 37.5 ± 8.0 min; p < 0.001), smaller craniotomy areas (472.7 ± 56.7 vs. 617.4 ± 89.7 mm2; p < 0.001), and reduced bone defects (141.8 ± 33.5 vs. 233.2 ± 71.1 mm2; p < 0.001). Bone defect (OR: 1.012; 95% CI: 1.005-1.018; p < 0.001) was found to be significantly associated with persistent headache in the multivariate analysis. CONCLUSIONS: Bone defects constitute an independent risk factor for persistent headache attributed to retrosigmoid craniotomy. The 3D CTV image-guided technique effectively reduces the size of bone defects, thereby leading to a reduced incidence of persistent headache postoperatively.
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BACKGROUND: Carotenoids play key roles in photosynthesis and are widely used in foods as natural pigments, antioxidants, and health-promoting compounds. Enhancing carotenoid production in microalgae via biotechnology has become an important area of research. RESULTS: We knocked out the Na+ /Ca2+ antiporter gene slr0681 in Synechocystis sp. PCC 6803 via homologous recombination and evaluated the effects on carotenoid production under normal (NL) and high-light (HL) conditions. On day 7 of NL treatment in calcium ion (Ca2+ )-free medium, the cell density of Δslr0681 decreased by 29% compared to the wild type (WT). After 8 days of HL treatment, the total carotenoid contents decreased by 35% in Δslr0681, and the contents of individual carotenoids were altered: myxoxanthophyll, echinenone, and ß-carotene contents increased by 10%, 50%, and 40%, respectively, while zeaxanthin contents decreased by ~40% in Δslr0681 versus the WT. The expression patterns of carotenoid metabolic pathway genes also differed: ipi expression increased by 1.2- to 8.5-fold, whereas crtO and crtR expression decreased by ~90% and 60%, respectively, in ∆slr0681 versus the WT. In addition, in ∆slr0681, the expression level of psaB (encoding a photosystem I structural protein) doubled, whereas the expression levels of the photosystem II genes psbA2 and psbD decreased by ~53% and 84%, respectively, compared to the WT. CONCLUSION: These findings suggest that slr0681 plays important roles in regulating carotenoid biosynthesis and structuring of the photosystems in Synechocystis sp. This study provides a theoretical basis for the genetic engineering of microalgae photosystems to increase their economic benefits and lays the foundation for developing microalgae germplasm resources with high carotenoid contents. © 2023 Society of Chemical Industry.
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Synechocystis , Synechocystis/genética , Synechocystis/metabolismo , Proteínas de Bactérias/metabolismo , Carotenoides/metabolismo , beta Caroteno/metabolismo , Zeaxantinas/metabolismoRESUMO
The adhesion of H2 bubbles on the electrode surface is one of the main factors limiting the performance of H2 evolution of electrolytic water, especially at high current density. To overcome this problem, here a "quasi-gas phase" electrolytic water reaction system based on capillary effect is proposed for the first time to improve the mass transfer efficiency of H2. The typical feature of this reaction system is that the main site of H2 evolution reaction is transferred from the bulk aqueous solution to the gas phase environment above the bulk aqueous solution, thus effectively inhibiting the aggregation of H2 bubbles and reducing the resistance of their diffusion away. Electrochemical test results show that the proposed quasi-gas phase system can significantly reduce the potential required in H2 evolution reaction process at high current density compared with the conventional electrolytic reaction system. Specifically, the overpotential potential is reduced by 0.31â V when the H2 evolution current density of 250â mA cm-2 is achieved.
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Although oxygen vacancies (Ovs) have been intensively studied in single semiconductor photocatalysts, exploration of intrinsic mechanisms and in-depth understanding of Ovs in S-scheme heterojunction photocatalysts are still limited. Herein, a novel S-scheme photocatalyst made from WO3-Ov/In2S3 with Ovs at the heterointerface is rationally designed. The microscopic environment and local electronic structure of the S-scheme heterointerface are well optimized by Ovs. Femtosecond transient absorption spectroscopy (fs-TAS) reveals that Ovs trigger additional charge movement routes and therefore increase charge separation efficiency. In addition, Ovs have a synergistic effect on the thermodynamic and kinetic parameters of S-scheme photocatalysts. As a result, the optimal photocatalytic performance is significantly improved, surpassing that of single component WO3-Ov and In2S3 (by 35.5 and 3.9â times, respectively), as well as WO3/In2S3 heterojunction. This work provides new insight into regulating the photogenerated carrier dynamics at the heterointerface and also helps design highly efficient S-scheme photocatalysts.
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Hairy cell leukemia (HCL) is a B-lymphoma induced by BRAF(V600E) mutation. However, introducing BRAF(V600E) in B-lymphocytes fails to induce hematological malignancy, suggesting that BRAF(V600E) needs concurrent mutations to drive HCL ontogeny. To resolve this issue, here we surveyed human HCL genomic sequencing data. Together with previous reports, we speculated that the tumor suppressor TP53, P27, or PTEN restrict the oncogenicity of BRAF(V600E) in B-lymphocytes, and therefore that their loss-of-function facilitates BRAF(V600E)-driven HCL ontogeny. Using genetically modified mouse models, we demonstrate that indeed BRAF(V600E)KI together with Trp53KO or pTENKO in B-lymphocytes induces chronic lymphoma with pathological features of human HCL. To further understand the cellular programs essential for HCL ontogeny, we profiled the gene expression of leukemic cells isolated from BRAF(V600E)KI and Trp53KO or pTENKO mice, and found that they had similar but different gene expression signatures that resemble that of M2 or M1 macrophages. In addition, we examined the expression signature of transcription factors/regulators required for germinal center reaction and memory B cell versus plasma cell differentiation in these leukemic cells and found that most transcription factors/regulators essential for these programs were severely inhibited, illustrating why hairy cells are arrested at a transitional stage between activated B cells and memory B cells. Together, our study has uncovered concurrent mutations required for HCL ontogeny, revealed the B cell origin of hairy cells and investigated the molecular basis underlying the unique pathological features of the disease, with important implications for HCL research and treatment.
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Leucemia de Células Pilosas , Animais , Humanos , Camundongos , Linfócitos B/metabolismo , Leucemia de Células Pilosas/genética , Leucemia de Células Pilosas/metabolismo , Leucemia de Células Pilosas/patologia , Mutação , Proteínas Proto-Oncogênicas B-raf , Fatores de Transcrição/genéticaRESUMO
Skull bone marrow is thought to be an immune tissue closely associated with the central nervous system (CNS). Recent studies have focused on the role of skull bone marrow in central nervous system disorders. In this study, we performed single-cell RNA sequencing on ipsilateral and contralateral skull bone marrow cells after experimental stroke and then performed flow cytometry and analysis of cytokine expression. Skull marrow showed lateralization in response to stroke. Lateralization is demonstrated primarily by the proliferation and differentiation of myeloid and lymphoid lineage cells in the skull bone marrow adjacent to the ischemic region, with an increased proportion of neutrophils compared to monocytes. Analysis of chemokines in the skull revealed marked differences in chemotactic signals between the ipsilateral and contralateral skull, whereas sympathetic signals innervating the skull did not affect cranial bone marrow lateralization. Osteopontin (OPN) is involved in region-specific activation of the skull marrow that promotes inflammation in the meninges, and inhibition of OPN expression improves neurological function.
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Medula Óssea , Osteopontina , Acidente Vascular Cerebral , Animais , Camundongos , Isquemia , Osteopontina/metabolismo , Crânio/metabolismoRESUMO
BACKGROUND: Subarachnoid hemorrhage (SAH) is an uncommon type of potentially fatal stroke. The pathophysiological mechanisms of brain injury remain unclear, which hinders the development of drugs for SAH. We aimed to investigate the pathophysiological mechanisms of SAH and to elucidate the cellular and molecular biological response to SAH-induced injury. METHODS: A cross-species (human and mouse) multiomics approach combining high-throughput data and bioinformatic analysis was used to explore the key pathophysiological processes and cells involved in SAH-induced brain injury. Patient data were collected from the hospital (n = 712). SAH was established in adult male mice via endovascular perforation, and flow cytometry, a bone marrow chimera model, qPCR, and microglial depletion experiments were conducted to explore the origin and chemotaxis mechanism of the immune cells. To investigate cell effects on SAH prognosis, murine neurological function was evaluated based on a modified Garcia score, pole test, and rotarod test. RESULTS: The bioinformatics analysis confirmed that inflammatory and immune responses were the key pathophysiological processes after SAH. Significant increases in the monocyte levels were observed in both the mouse brains and the peripheral blood of patients after SAH. Ly6C-high monocytes originated in the bone marrow, and the skull bone marrow contribute a higher proportion of these monocytes than neutrophils. The mRNA level of Ccl2 was significantly upregulated after SAH and was greater in CD11b-positive than CD11b-negative cells. Microglial depletion, microglial inhibition, and CCL2 blockade reduced the numbers of Ly6C-high monocytes after SAH. With CCR2 antagonization, the neurological function of the mice exhibited a slow recovery. Three days post-SAH, the monocyte-derived dendritic cell (moDC) population had a higher proportion of TNF-α-positive cells and a lower proportion of IL-10-positive cells than the macrophage population. The ratio of moDCs to macrophages was higher on day 3 than on day 5 post-SAH. CONCLUSIONS: Inflammatory and immune responses are significantly involved in SAH-induced brain injury. Ly6C-high monocytes derived from the bone marrow, including the skull bone marrow, infiltrated into mouse brains via CCL2 secreted from microglia. Moreover, Ly6C-high monocytes alleviated neurological dysfunction after SAH.
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Lesões Encefálicas , Acidente Vascular Cerebral , Hemorragia Subaracnóidea , Humanos , Camundongos , Masculino , Animais , Monócitos , Hemorragia Subaracnóidea/complicações , Lesões Encefálicas/etiologia , Macrófagos , Camundongos Endogâmicos C57BLRESUMO
Perovskite oxides stand out as emerging oxygen evolution reaction (OER) catalysts on account of their effective electrocatalytic performance and low costs. Nevertheless, perovskite oxides suffer from severe bubble overpotential and inhibited electrochemical performance in large current densities due to their small specific surface areas and structural compactness. Herein, the study highlights the electrospun nickel-substituted La0.5 Sr0.5 FeO3-δ (LSF) porous perovskite nanofibers, that is, La0.5 Sr0.5 Fe1-x Nix O3-δ (denoted as ES-LSFN-x, x = 0, 0.1, 0.3, and 0.5), as high-performance OER electrocatalysts. The most effective La0.5 Sr0.5 Fe0.5 Ni0.5 O3-δ (ES-LSFN-0.5) nanofibers suggest a larger specific surface area, higher porosity, and faster mass transfer than the counterpart sample prepared by conventional sol-gel method (SG-LSFN-0.5), showing notably increased geometric and intrinsic activities. The bubble visualization results demonstrate that the enriched and nano-sized porosity of ES-LSFN-0.5 enables reinforced aerophobicity and rapid detachment of oxygen bubbles, thereby reducing the bubble overpotential and enhancing the electrochemical performance. As a result, the ES-LSFN-0.5-based anion exchange membrane water electrolysis delivers a superior stability of 100 h while the SG-LSFN-0.5 counterpart degrades rapidly within 20 h under a current density of 100 mA cm-2 . The results highlight the advantage of porous electrocatalysts in optimizing the performance of large current density water electrolysis devices by reducing the bubble overpotential.
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A strictly anaerobic, organohalide-respiring bacterium, designated strain GPT, was characterized using a polyphasic approach. GPT is Gram-stain-negative, non-spore-forming and non-motile. Cells are irregular cocci ranging between 0.6 and 0.9 µm in diameter. GPT couples growth with the reductive dechlorination of 1,2-dichloroethane, vinyl chloride and all polychlorinated ethenes, except tetrachloroethene, yielding ethene and inorganic chloride as dechlorination end products. H2 and formate serve as electron donors for organohalide respiration in the presence of acetate as carbon source. Major cellular fatty acids include C16â:â0, C18â:â1ω9c, C16â:â1, C14â:â0 and C18â:â0. On the basis of 16S rRNA gene phylogeny, GPT is most closely related to Dehalogenimonas formicexedens NSZ-14T and Dehalogenimonas alkenigignens IP3-3T with 99.8 and 97.4â% sequence identities, respectively. Genome-wide pairwise comparisons based on average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization do not support the inclusion of GPT in previously described species of the genus Dehalogenimonas with validly published names. On the basis of phylogenetic, physiological and phenotypic traits, GPT represents a novel species within the genus Dehalogenimonas, for which the name Dehalogenimonas etheniformans sp. nov. is proposed. The type strain is GPT (= JCM 39172T = CGMCC 1.17861T).
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Ácidos Graxos , Vitis , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Composição de Bases , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Análise de Sequência de DNA , Bactérias Anaeróbias/genética , Oxirredução , Formiatos , Fosfolipídeos/químicaRESUMO
Pseudomonas sp. strain 273 grows with medium-chain terminally fluorinated alkanes under oxic conditions, releases fluoride, and synthesizes long-chain fluorofatty acids. To shed light on the genes involved in fluoroalkane metabolism, genome, and transcriptome sequencing of strain 273 grown with 1,10-difluorodecane (DFD), decane, and acetate were performed. Strain 273 harbors three genes encoding putative alkane monooxygenases (AlkB), key enzymes for initiating alkane degradation. Transcripts of alkB-2 were significantly more abundant in both decane- and DFD-grown cells compared to acetate-grown cells, suggesting AlkB-2 catalyzes the attack on terminal CH3 and CH2F groups. Coordinately expressed with alkB-2 was an adjacent gene encoding a fused ferredoxin-ferredoxin reductase (Fd-Fdr). Phylogenetic analysis distinguished AlkB that couples with fused Fd-Fdr reductases from AlkB with alternate architectures. A gene cluster containing an (S)-2-haloacid dehalogenase (had) gene was up-regulated in cells grown with DFD, suggesting a possible role in the removal of the ω-fluorine. Genes involved in long-chain fatty acid biosynthesis were not differentially expressed during growth with acetate, decane, or DFD, suggesting the bacterium's biosynthetic machinery does not discriminate against monofluoro-fatty acid intermediates. The analysis sheds first light on genes and catalysts involved in the microbial metabolism of fluoroalkanes.
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Fifteen undescribed Stemona alkaloids, named as stemarines A-O (1-15), along with 25 known alkaloids (16-40), were isolated and identified from the roots of Stemona mairei (H.Lév.)K.Krause (Stemonaceae). Their structures were elucidated through the analysis of the NMR spectra, mass data, and computational chemistry. All the hitherto undescribed compounds possess a pyrrolo[1,2-α]azepine core structure but differ in important structural features, which reflects their nematocidal activities. Alkaloids 3-6 featured a carboxylic side chain and exhibited significant nematocidal activity against the nematode Caenorhabditis elegans. Transections of fresh roots combined with application of the Dragendorff' reagent on the tissue indicated accumulation of alkaloids mainly in the epidermis and the pith. These results suggest the key pharmacophore of these alkaloids lies in the aliphatic side chain of these compounds and its spatial distribution in the roots indicate protective effects against underground herbivores.
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Alcaloides , Stemonaceae , Stemonaceae/química , Antinematódeos , Extratos Vegetais/química , Alcaloides/farmacologia , Alcaloides/química , Raízes de Plantas/química , Estrutura MolecularRESUMO
OBJECTIVE: Small extracellular vesicle (sEV)-mediated intercellular communication is increasingly the key for the understanding of venous malformations (VMs). This study aims to clarify the detailed changes of sEVs in VMs. SUBJECTS AND METHODS: Fifteen VM patients without treatment history and twelve healthy donors were enrolled in the study. sEVs were isolated from both fresh lesions and cell supernatant, and were examined by western blotting, nanoparticle tracking analysis and transmission electron microscopy. Western blot analysis, immunohistochemistry and immunofluorescence were adopted to screening candidate regulator of sEV size. Specific inhibitors and siRNA were employed to validate the role of dysregulated p-AKT/vacuolar protein sorting-associated protein 4B (VPS4B) signaling on the size of sEVs in endothelial cells. RESULTS: The size of sEVs derived from both VM lesion tissues and cell model was significantly increased. VPS4B, whose expression level was mostly significantly downregulated in VM endothelial cells, was responsible for the size change of sEVs. Targeting abnormal AKT activation corrected the size change of sEVs by recovering the expression level of VPS4B. CONCLUSION: Downregulated VPS4B in endothelial cells, resulted from abnormally activated AKT signaling, contributed to the increased size of sEVs in VMs.
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Colorectal cancer (CRC) is a malignant tumor of the gastrointestinal tract that significantly impacts the health of patients and lacks promising methods of diagnosis. Tumor-associated macrophages (TAMs) are involved in CRC progression, and their function is regulated by long non-coding RNAs (lncRNAs). The lncRNA NBR2 was recently reported as an oncogene, whose function in CRC remains uncertain. The present study aimed to investigate the biological function of lncRNA NBR2 in the progression of CRC and its underlying molecular mechanisms. Ten pairs of clinical CRC and para-carcinoma tissues were collected to determine the expression levels of lncRNA NBR2 and miR-19a, and the polarization state of TAMs. Quantitative reverse transcriptase-polymerase chain reaction was used to evaluate the expression of miR-19a, and western blotting was used to determine the expression levels of tumor necrosis factor-α, human leukocyte antigen-DR, arginase-1, CD163, CD206, interleukin-4, AMP-activated protein kinase (AMPK), p-AMPK, hypoxia-inducible factor-1α (HIF-1α), protein kinase B (AKT), p-AKT, mechanistic target of rapamycin (mTOR), and p-mTOR in TAMs. The proliferative ability of HCT-116 cells was detected using the CCK8 assay, and the migratory ability of HCT-116 cells was evaluated using the Transwell assay. The interaction between lncRNA NBR2 and miR-19a was determined using the luciferase assay. The lncRNA NBR2 was downregulated and miR-19a was highly expressed in CRC cells, accompanied by a high M2 polarization. Downregulated miR-19a promoted M1 polarization, activated AMPK, suppressed HIF-1α and AKT/mTOR signaling pathways, and promoted antitumor properties in NBR2-overexpressed TAMs, which were all reversed by the introduction of the miR-19a mimic. LncRNA NBR2 was verified to target miR-19a in macrophages according to the results of the luciferase assay. Collectively, lncRNA NBR2 may suppress the progression of CRC by downregulating miR-19a to regulate M2 macrophage polarization.
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Neoplasias Colorretais , MicroRNAs , RNA Longo não Codificante , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Luciferases/metabolismo , Macrófagos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Hydrocephalus has been observed in rats with spontaneous hypertension (SHRs). It has been demonstrated that activation of the oxidative stress related protein retinoic acid receptor alpha (RARα) has neuroprotective impacts. Our investigation aims to determine the potential role and mechanism of RARα in hydrocephalus. The RARα-specific agonist (Am80) and RARα inhibitor (AGN196996) were used to investigate the role of RARα in cerebrospinal fluid (CSF) secretion in the choroid plexus of SHRs. Evaluations of CSF secretion, ventricular volume, Western blotting, and immunofluorescent staining were performed. Hydrocephalus and CSF hypersecretion were identified in SHRs but not in Wistar-Kyoto rats, occurring at the age of 7 weeks. The RARα/MAFB/MSR1 pathway was also activated in SHRs. Therapy with Am80 beginning in week 5 decreased CSF hypersecretion, hydrocephalus development, and pathological changes in choroid plexus alterations by week 7. AGN196996 abolished the effect of Am80. In conclusion, activation of the RARα attenuated CSF hypersecretion to inhibit hydrocephalus development via regulating the MAFB/MSR1 pathway. RARα may act as a possible therapeutic target for hydrocephalus.