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Plants protect themselves with a vast array of toxic secondary metabolites, yet most plants serve as food for insects. The evolutionary processes that allow herbivorous insects to resist plant defenses remain largely unknown. The whitefly Bemisia tabaci is a cosmopolitan, highly polyphagous agricultural pest that vectors several serious plant pathogenic viruses and is an excellent model to probe the molecular mechanisms involved in overcoming plant defenses. Here, we show that, through an exceptional horizontal gene transfer event, the whitefly has acquired the plant-derived phenolic glucoside malonyltransferase gene BtPMaT1. This gene enables whiteflies to neutralize phenolic glucosides. This was confirmed by genetically transforming tomato plants to produce small interfering RNAs that silence BtPMaT1, thus impairing the whiteflies' detoxification ability. These findings reveal an evolutionary scenario whereby herbivores harness the genetic toolkit of their host plants to develop resistance to plant defenses and how this can be exploited for crop protection.
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Hemípteros/genética , Proteínas de Insetos/metabolismo , Solanum lycopersicum/genética , Toxinas Biológicas/metabolismo , Animais , Transferência Genética Horizontal , Genes de Plantas , Glucosídeos/química , Glucosídeos/metabolismo , Hemípteros/fisiologia , Herbivoria , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Mucosa Intestinal/metabolismo , Solanum lycopersicum/metabolismo , Malonil Coenzima A/metabolismo , Filogenia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , Toxinas Biológicas/químicaRESUMO
Cachexia represents a leading cause of morbidity and mortality in various cancers, chronic inflammation and infections. Understanding of the mechanisms that drive cachexia has remained limited, especially for infection-associated cachexia (IAC). In the present paper we describe a model of reversible cachexia in mice with chronic viral infection and identify an essential role for CD8+ T cells in IAC. Cytokines linked to cancer-associated cachexia did not contribute to IAC. Instead, virus-specific CD8+ T cells caused morphologic and molecular changes in the adipose tissue, which led to depletion of lipid stores. These changes occurred at a time point that preceded the peak of the CD8+ T cell response and required T cell-intrinsic type I interferon signaling and antigen-specific priming. Our results link systemic antiviral immune responses to adipose-tissue remodeling and reveal an underappreciated role of CD8+ T cells in IAC.
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Linfócitos T CD8-Positivos/imunologia , Caquexia/etiologia , Viroses/complicações , Viroses/imunologia , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/imunologia , Tecido Adiposo/metabolismo , Tecido Adiposo/virologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Caquexia/diagnóstico por imagem , Caquexia/metabolismo , Caquexia/patologia , Doença Crônica , Citocinas/sangue , Citocinas/metabolismo , Feminino , Interferon Tipo I/metabolismo , Metabolismo dos Lipídeos , Lipólise , Ativação Linfocitária/imunologia , Vírus da Coriomeningite Linfocítica , Imageamento por Ressonância Magnética/métodos , Masculino , Camundongos , Transdução de Sinais , Viroses/virologiaRESUMO
Hypothetical chloroplast open reading frames (ycfs) are putative genes in the plastid genomes of photosynthetic eukaryotes. Many ycfs are also conserved in the genomes of cyanobacteria, the presumptive ancestors of present-day chloroplasts. The functions of many ycfs are still unknown. Here, we generated knock-out mutants for ycf51 (sll1702) in the cyanobacterium Synechocystis sp. PCC 6803. The mutants showed reduced photoautotrophic growth due to impaired electron transport between photosystem II (PSII) and PSI. This phenotype results from greatly reduced PSI content in the ycf51 mutant. The ycf51 disruption had little effect on the transcription of genes encoding photosynthetic complex components and the stabilization of the PSI complex. In vitro and in vivo analyses demonstrated that Ycf51 cooperates with PSI assembly factor Ycf3 to mediate PSI assembly. Furthermore, Ycf51 interacts with the PSI subunit PsaC. Together with its specific localization in the thylakoid membrane and the stromal exposure of its hydrophilic region, our data suggest that Ycf51 is involved in PSI complex assembly. Ycf51 is conserved in all sequenced cyanobacteria, including the earliest branching cyanobacteria of the Gloeobacter genus, and is also present in the plastid genomes of glaucophytes. However, Ycf51 has been lost from other photosynthetic eukaryotic lineages. Thus, Ycf51 is a PSI assembly factor that has been functionally replaced during the evolution of oxygenic photosynthetic eukaryotes.
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Proteínas de Bactérias , Fases de Leitura Aberta , Complexo de Proteína do Fotossistema I , Synechocystis , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema I/genética , Synechocystis/genética , Synechocystis/metabolismo , Fases de Leitura Aberta/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Cloroplastos/metabolismo , Fotossíntese/genética , Tilacoides/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Complexo de Proteína do Fotossistema II/genética , MutaçãoRESUMO
Increased receptor binding affinity may allow viruses to escape from Ab-mediated inhibition. However, how high-affinity receptor binding affects innate immune escape and T cell function is poorly understood. In this study, we used the lymphocytic choriomeningitis virus (LCMV) murine infection model system to create a mutated LCMV exhibiting higher affinity for the entry receptor α-dystroglycan (LCMV-GPH155Y). We show that high-affinity receptor binding results in increased viral entry, which is associated with type I IFN (IFN-I) resistance, whereas initial innate immune activation was not impaired during high-affinity virus infection in mice. Consequently, IFN-I resistance led to defective antiviral T cell immunity, reduced type II IFN, and prolonged viral replication in this murine model system. Taken together, we show that high-affinity receptor binding of viruses can trigger innate affinity escape including resistance to IFN-I resulting in prolonged viral replication.
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Coriomeningite Linfocítica , Internalização do Vírus , Camundongos , Animais , Camundongos Knockout , Vírus da Coriomeningite Linfocítica/fisiologia , Replicação Viral , Camundongos Endogâmicos C57BL , Imunidade InataRESUMO
Chlorophyll is an essential photosynthetic pigment but also a strong photosensitizer. Excessive free chlorophyll and its precursors can cause oxidative damage to photosynthetic organisms. Cyanobacteria are the oldest oxygenic photosynthetic organisms and the ancestors of the chloroplast. Owing to their complex habitats, cyanobacteria require precise regulation of chlorophyll synthesis to respond to environmental factors, especially changes in light. Chlorophyll synthase, encoded by chlG, is the enzyme catalyzing the final step of chlorophyll biosynthesis, which is closely related to photosynthesis biogenesis. However, the transcriptional regulation on chlG remains unclear. Here, the transcription factor, regulator of photosynthesis and photopigment-related gene expression A (RppA) was identified to bind to the chlG promoter by screening a yeast one-hybrid library in the cyanobacterium Synechocystis sp. PCC 6803. The rppA knock-out mutant showed a phenotype of slow growth and severe oxidative damage under dark-light transition conditions. The up-regulated transcriptional expression of chlG was significantly higher and more chlorophyll and its precursors accumulated in the rppA knock-out mutant than those in the wild-type strain during the transition from darkness to light, indicating RppA represses the expression of chlG in Synechocystis. Meanwhile, RppA could synchronously promote the transcription of carotenoids biosynthesis-related genes to enhance carotenoids synthesis during the dark-light transition. These results reveal synergistic regulation of chlorophyll and carotenoids biosynthesis in cyanobacteria in response to frequent dark-light transitions, which slows down chlorophyll biosynthesis while promoting carotenoids biosynthesis to avoid oxidative damage caused by excessive reactive oxygen species accumulation.
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IL-6 family members contribute to host defense through the stimulation of acute-phase signaling, hematopoiesis, immune reactions, and regenerative processes. To investigate essential mechanisms that are linked toward a constitutively activated gp130 signaling, we generated and characterized a mouse model that reflects a constitutive and cytokine-independent activation of JAK/STAT3 signaling by Lgp130 in CD4- and CD8-positive T cells. Lgp130 is an engineered form of gp130 in which dimerization and activation are forced by a leucine zipper. T cell-specific Lgp130 activation resulted in massive phenotypical abnormalities, including splenomegaly, lymphadenopathy, and an upregulation of innate immune system components shown by hyperinflammatory signatures in several organs. Moreover, T cell-restricted expression of Lgp130 resulted in increased numbers of cytotoxic and regulatory T cells, especially in lymph nodes. Consistent with this, we found an elevated platelet production and increase in megakaryocytes in the spleen and bone marrow that are causative for an acute thrombocytosis accompanied by anemia. Due to a shortened life span of T cell-specific Lgp130 mice, we could also show that next to an overall increase in regulatory cell-cycle genes, an activation of p53 and increased expression of p21 provide evidence for a senescence-like phenotype. Together, these data suggest that T cell-restricted gp130 activation is not only involved in autoimmune processes but also in senescence-associated aging. Therefore, Lgp130 expression in T cells might be a suitable model to study inflammation and disease.
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Senilidade Prematura , Animais , Camundongos , Receptor gp130 de Citocina/genética , Receptor gp130 de Citocina/metabolismo , Hematopoese , Baço/metabolismo , Fator de Transcrição STAT3/metabolismoRESUMO
Desert-inhabiting cyanobacteria can tolerate extreme desiccation and quickly revive after rehydration. The regulatory mechanisms that enable their vegetative cells to resurrect upon rehydration are poorly understood. In this study, we identified a single gene family of high light-inducible proteins (Hlips) with dramatic expansion in the Nostoc flagelliforme genome and found an intriguingly special convergence formed through four tandem gene duplication. The emerged four independent hlip genes form a gene cluster (hlips-cluster) and respond to dehydration positively. The gene mutants in N. flagelliforme were successfully generated by using gene-editing technology. Phenotypic analysis showed that the desiccation tolerance of hlips-cluster-deleted mutant decreased significantly due to impaired photosystem II repair, whereas heterologous expression of hlips-cluster from N. flagelliforme enhanced desiccation tolerance in Nostoc sp. PCC 7120. Furthermore, a transcription factor Hrf1 (hlips-cluster repressor factor 1) was identified and shown to coordinately regulate the expression of hlips-cluster and desiccation-induced psbAs. Hrf1 acts as a negative regulator for the adaptation of N. flagelliforme to the harsh desert environment. Phylogenetic analysis revealed that most species in the Nostoc genus possess both tandemly repeated Hlips and Hrf1. Our results suggest convergent evolution of desiccation tolerance through the coevolution of tandem Hlips duplication and Hrf1 in subaerial Nostoc species, providing insights into the mechanism of desiccation tolerance in photosynthetic organisms.
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Nostoc , Complexo de Proteína do Fotossistema II , Dessecação , Nostoc/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Filogenia , Fatores de Transcrição/metabolismoRESUMO
Aqueous zinc-ion batteries (AZIBs) have garnered significant attention in the realm of large-scale and sustainable energy storage, primarily owing to their high safety, low cost, and eco-friendliness. Aqueous electrolytes, serving as an indispensable constituent, exert a direct influence on the electrochemical performance and longevity of AZIBs. Nonetheless, conventional aqueous electrolytes often encounter formidable challenges in AZIB applications, such as the limited electrochemical stability window and the zinc dendrite growth. In response to these hurdles, a series of advanced aqueous electrolytes have been proposed, such as "water-in-salt" electrolytes, aqueous eutectic electrolytes, molecular crowding electrolytes, and hydrogel electrolytes. This comprehensive review commences by presenting an in-depth overview of the fundamental compositions, principles, and distinctive characteristics of various advanced aqueous electrolytes for AZIBs. Subsequently, we systematically scrutinizes the recent research progress achieved with these advanced aqueous electrolytes. Furthermore, we summarizes the challenges and bottlenecks associated with these advanced aqueous electrolytes, along with offering recommendations. Based on the optimization of advanced aqueous electrolytes, this review outlines future directions and potential strategies for the development of high-performance AZIBs. This review is anticipated to provide valuable insights into the development of advanced electrolyte systems for the next generation of stable and sustainable multi-valent secondary batteries.
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Absorption of the long-wave infrared from human beings and the surroundings is a key step to infrared imaging and sensing. Here we demonstrate a flexible and transparent broadband infrared absorber using the photoresist-assisted metamaterials fabricated by one-step laser direct writing. The photoresist is patterned by the laser as an insulator layer as well as a mask to build the complementary bilayer metamaterials without lithography. The average absorptivity is 94.5% from 8 to 14â µm in experiment due to the broadband destructive interference of the reflected beam explained by the Fabry-Perot cavity model. The proposed absorber is applicable to various substrates with additional merits of polarization insensitivity and large angle tolerance, which offers a promising solution for thermal detection and management.
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Tissue damage caused by viral hepatitis is a major cause of morbidity and mortality worldwide. Using a mouse model of viral hepatitis, we identified virus-induced early transcriptional changes in the redox pathways in the liver, including downregulation of superoxide dismutase 1 (Sod1). Sod1(-/-) mice exhibited increased inflammation and aggravated liver damage upon viral infection, which was independent of T and NK cells and could be ameliorated by antioxidant treatment. Type I interferon (IFN-I) led to a downregulation of Sod1 and caused oxidative liver damage in Sod1(-/-) and wild-type mice. Genetic and pharmacological ablation of the IFN-I signaling pathway protected against virus-induced liver damage. These results delineate IFN-I mediated oxidative stress as a key mediator of virus-induced liver damage and describe a mechanism of innate-immunity-driven pathology, linking IFN-I signaling with antioxidant host defense and infection-associated tissue damage. VIDEO ABSTRACT.
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Hepatócitos/imunologia , Interferon Tipo I/imunologia , Estresse Oxidativo/imunologia , Superóxido Dismutase/imunologia , Animais , Antioxidantes/metabolismo , Hepatite Viral Animal/imunologia , Imunidade Inata/imunologia , Inflamação/imunologia , Células Matadoras Naturais/imunologia , Fígado/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução , Transdução de Sinais/imunologia , Superóxido Dismutase-1 , Linfócitos T/imunologia , Transcrição Gênica/imunologiaRESUMO
Advancements in cost-effective, high-performance alkaline water-splitting systems are crucial for the hydrogen industry. While the significance of electrode material design has been widely acknowledged, the practical implementation of these advancements remains challenging. In this study, we focused on the holistic design of the electrolysis system and successfully developed a novel alkaline water-splitting electrolyzer. The unique configuration of our electrolyzer allows the designed NiFe-LDH/carbon cloth gas diffusion anode to interact solely with the PVA-based gel membrane and air, enabling the direct discharge of oxygen into the gas phase. This innovative feature accelerates anode bubble overflow, reduces gas interference, and decreases the system impedance by minimizing electrode spacing. As a result, by utilizing the NiFeSn-alloy/nickel mesh cathode, our electrolyzer achieves a high current density of 308 mA cm-2 at a cell voltage of 2.0 V and demonstrates exceptional stability over 1000 h.
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Chirality is ubiquitous in nature, and closely related to biological phenomena. Nature-originated nanomaterials such as cellulose nanocrystals (CNCs) are able to self-assemble into hierarchical chiral nematic CNC films and impart handedness to nano and micro scale. However, the effects of the chiral nematic surfaces on cell adhesion are still unknown. Herein, this work presents evidence that the left-handed self-assembled chiral nematic CNC films (L-CNC) significantly improve the adhesion of L929 fibroblasts compared to randomly arranged isotropic CNC films (I-CNC). The fluidic force microscopy-based single-cell force spectroscopy is introduced to assess the cell adhesion forces on the substrates of L-CNC and I-CNC, respectively. With this method, a maximum adhesion force of 133.2 nN is quantified for mature L929 fibroblasts after culturing for 24 h on L-CNC, whereas the L929 fibroblasts exert a maximum adhesion force of 78.4 nN on I-CNC under the same condition. Moreover, the instant SCFS reveals that the integrin pathways are involved in sensing the chirality of substrate surfaces. Overall, this work offers a starting point for the regulation of cell adhesion via the self-assembled nano and micro architecture of chiral nematic CNC films, with potential practical applications in tissue engineering and regenerative medicine.
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HSO radicals play an important role in the photochemical processes in combustion, the atmosphere, and the interstellar medium. In this work, we perform a high-level ab initio study on the electronic excited states of HSO using the internally contracted multireference configuration interaction methods including Davidson correction (icMRCI + Q) in combination with the correlation-consistent basis sets. The molecular geometries, vertical transition energies, oscillator strengths, and electronic configurations of 19 electronic states of HSO are computed. The electronic potential energy curves of HSO along the bond lengths and bond angles are presented. Based on our calculations, the interactions between the electronic states involved in the ultraviolet region and the mechanism of photodissociation are discussed, which will lay a foundation for revealing the dissociation dynamics of gas-phase HSO molecules in outer space and the earth's atmosphere.
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We perform a high-level ab initio study on 20 electronic states of monochlorosilylene (HSiCl) using an internally contracted multireference configuration interaction method including Davidson correction (icMRCI+Q). The spin-orbit coupling (SOC) effect is investigated, leading to splitting of the 20 spin-orbit-free states into 50 spin-orbit-coupled states. Vertical transition energies, oscillator strengths, and potential energy curves are presented with and without considering the SOC effect. Analysis indicates that the SOC effect plays an important role, especially for the high-lying excited states of HSiCl. The state interaction and the dynamics of the electronic states of HSiCl in the ultraviolet region are discussed based on our calculation results. Our study paves the way to understanding the behavior of electronic excited states of monochlorosilylene.
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Primary biliary cholangitis (PBC) is a cholestatic liver disease characterized by immune-mediated injury to small bile ducts. Although PBC is an autoimmune disease, the effectiveness of conventional immunosuppressive therapy is disappointing. Nearly 40% of PBC patients do not respond to the first-line drug UDCA. Without appropriate intervention, PBC patients eventually progress to liver cirrhosis and even death. There is an urgent need to develop new therapies. The gut-liver axis emphasizes the interconnection between the gut and the liver, and evidence is increasing that gut microbiota and bile acids play an important role in the pathogenesis of cholestatic diseases. Dysbiosis of gut microbiota, imbalance of bile acids, and immune-mediated bile duct injury constitute the triad of pathophysiology in PBC. Autoimmune cholangitis has the potential to be improved through immune system modulation. Considering the failure of conventional immunotherapies and the involvement of gut microbiota and bile acids in the pathogenesis, targeting immune factors associated with them, such as bile acid receptors, microbial-derived molecules, and related specific immune cells, may offer breakthroughs. Understanding the gut microbiota-bile acid network and related immune dysfunctions in PBC provides a new perspective on therapeutic strategies. Therefore, we summarize the latest advances in research of gut microbiota and bile acids in PBC and, for the first time, explore the possibility of related immune factors as novel immunotherapy targets. This article discusses potential therapeutic approaches focusing on regulating gut microbiota, maintaining bile acid homeostasis, their interactions, and related immune factors.
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Ácidos e Sais Biliares , Microbioma Gastrointestinal , Cirrose Hepática Biliar , Humanos , Ácidos e Sais Biliares/metabolismo , Cirrose Hepática Biliar/imunologia , Cirrose Hepática Biliar/terapia , Cirrose Hepática Biliar/metabolismo , Cirrose Hepática Biliar/microbiologia , Animais , Disbiose/imunologiaRESUMO
BACKGROUND: Existing treatments for primary dysmenorrhoea (PD), such as NSAIDs, impart side effects. Ge-Gen decoction (GGD), a traditional Chinese medicine, has shown promise in treating PD, but its exact mechanisms remain unclear. Here, we aimed to investigate the efficiency of GGD in alleviating PD using a rat model to understand its precise mechanism of action. METHODS: We established a rat model of dysmenorrhoea induced by oestradiol and oxytocin. The PD rats were administered GGD or Ibuprofen (positive control) intragastrically once daily for seven consecutive days. Serum levels of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2α), ß-endorphin (ß-EP), thromboxane B2 (TXB2), 6-keto-prostaglandin F1α (6-keto-PGF1α) were determined using an enzyme-linked immunosorbent assay (ELISA). The expression levels of oestrogen receptor alpha (ERα) and cyclooxygenase-2 (COX-2) in uterine tissue were measured using immunohistochemical assays, and those of phosphorylated and total extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) were assessed using western blot analysis. RESULTS: Treatment with GGD significantly reduced writhing behaviour, histopathological scores, and levels of COX-2, PGE2, and PGF2α in the serum of PD rats. Additionally, GGD increased ß-EP content and inhibited ERK1/2 activation and ERα expression in uterine tissues. CONCLUSIONS: The results of this study suggest that GGD alleviates PD in rats by suppressing the COX-2-mediated release of PGE2 and PGF2α, modulating the ERα/ERK1/2/COX-2 pathway, and increasing ß-EP content. These results provide insights into the potential mechanisms of GGD in treating PD and support its further investigation as an alternative therapy for this condition.
Ge-Gen decoction is commonly used to alleviate primary dysmenorrhoea. However, its anti-dysmenorrhoea mechanism remains elusive. In this study, using a rat model of primary dysmenorrhoea, we demonstrate that Ge-Gen decoction reduced the levels of cyclooxygenase-2, prostaglandin E2, and prostaglandin F2 alpha in serum and phosphorylated extracellular signal-regulated protein kinases 1 and 2 in the uterus. These results suggest that Ge-Gen decoction alleviates primary dysmenorrhoea via inactivation of the oestrogen receptor alpha/extracellular signal-regulated protein kinases 1 and 2/cyclooxygenase-2 pathway. This study enhances our understanding of the pathogenesis of primary dysmenorrhoea and may potentially inform the development of novel treatment approaches.
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Dismenorreia , Receptor alfa de Estrogênio , Humanos , Feminino , Ratos , Animais , Dismenorreia/tratamento farmacológico , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/uso terapêutico , Dinoprostona , Dinoprosta/uso terapêuticoRESUMO
BACKGROUND: Blood pressure (BP) management at the initial stage of stroke caused by large-vessel occlusion (LVO) remains challenging. We assessed the association between baseline BP and clinical and safety outcomes of endovascular treatment (EVT) in different stroke etiologies. METHODS: Patients with acute ischemic stroke and anterior circulation LVO were screened from a prospective, multicenter registry of EVT from November 2017 to March 2019. The primary outcome was poor 90-day outcome (modified Rankin Scale score 3-6). The safety outcome was 24 h post-procedure parenchymal hematoma (PH). The Trial of Org 101072 in Acute Stroke Treatment criteria were used for etiologic stroke classification. Restricted cubic spline and binary logistic regression analysis were performed to examine the association between study outcomes and natural log-transformed BP. RESULTS: In subgroup analyses, a U-shaped correlation existed between baseline mean arterial pressure (MAP) and poor outcome in large-artery atherosclerosis stroke only. Higher MAP was an independent risk factor compared with a central reference value (≥ 133 mm Hg vs 96-115 mm Hg; adjusted OR [aOR], 2.50; 95 % CI, 1.09 to 5.71, P = 0.030). Whereas elevated MAP was associated with PH (aOR, 1.58; 95 % CI 1.04 to 2.39, P = 0.030 for a ln10-unit increase in natural log-transformed MAP) in the range <110 mm Hg exclusively for cardioembolic stroke. CONCLUSION: Whether it is cause or epiphenomenon, baseline BP was associated with 90-day outcome in large-artery atherosclerosis stroke, whereas in cardioembolic stroke baseline BP was correlated with post-procedure PH within a certain range. Identifying these features based on etiological subtypes may offer a reference for BP management in acute LVO stroke.
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Pressão Sanguínea , Procedimentos Endovasculares , AVC Isquêmico , Sistema de Registros , Humanos , Masculino , Feminino , Idoso , Estudos Prospectivos , Pessoa de Meia-Idade , AVC Isquêmico/etiologia , Resultado do Tratamento , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/etiologia , Idoso de 80 Anos ou maisRESUMO
Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) was employed to investigate the impacts of Pruni Semen processed with different methods(raw and fried) on the liver and spleen metabolism in mice. A total of 24 male mice were randomly assigned to three groups: raw Pruni Semen group, fried Pruni Semen group, and control(deionized water) group. Mice in the three groups were orally administrated with 0.01 g·mL~(-1) Pruni Semen decoction or deionized water for one week. After that, the liver and spleen tissues were collected, and liquid chromatography-mass spectrometry(LC-MS)-based metabolomic analysis was carried out to investigate the impact of Pruni Semen on the liver and spleen metabolism in mice. Compared with thte control group, the raw Pruni Semen group showed up-regulation of 11 metabolites and down-regulation of 57 metabolites in the spleen(P<0.05), as well as up-regulation of 15 metabolites and down-regulation of 58 metabolites in the liver(P<0.05). The fried Pruni Semen group showed up-regulation of 31 metabolites and down-regulation of 10 metabolites in the spleen(P<0.05), along with up-regulation of 26 metabolites and down-regulation of 61 metabolites in the liver(P<0.05). The differential metabolites identified in the raw Pruni Semen group were primarily associated with alanine, aspartate, and glutamate metabolism, purine metabolism, amino sugar and nucleotide sugar metabolism, and D-glutamine and D-glutamate metabolism. The differential metabolites identified in the fried Pruni Semen group predominantly involved riboflavin metabolism, amino sugar and nucleotide sugar metabolism, purine metabolism, alanine, aspartate, and glutamate metabolism, D-glutamine and D-glutamate metabolism, and glutathione metabolism. The findings suggest that both raw and fried Pruni Semen have the potential to modulate the metabolism of the liver and spleen in mice by influencing the glutamine and glutamate metabolism.
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Ácido Glutâmico , Baço , Camundongos , Masculino , Animais , Sêmen , Glutamina , Ácido Aspártico , Metabolômica/métodos , Fígado/metabolismo , Alanina/metabolismo , Amino Açúcares/metabolismo , Água/metabolismo , Nucleotídeos/metabolismo , Purinas/metabolismo , Açúcares , Cromatografia Líquida de Alta Pressão , Biomarcadores/metabolismoRESUMO
The discovery of reduced flavin mononucleotide and fatty aldehydes as essential factors of light emission facilitated study of bacterial luminescence. Although the molecular mechanisms underlying bacterial luminescence have been studied for more than 60 years, the structure of the bacterial fatty acid reductase complex remains unclear. Here, we report the cryo-EM structure of the Photobacterium phosphoreum fatty acid reductase complex LuxC-LuxE to a resolution of 2.79 Å. We show that the active site Lys238/Arg355 pair of LuxE is >30 Å from the active site Cys296 of LuxC, implying that catalysis relies on a large conformational change. Furthermore, mutagenesis and biochemical experiments support that the L-shaped cleft inside LuxC plays an important role in substrate binding and reaction. We obtained a series of mutants with significantly improved activity as measured by in vitro bioluminescence assays and demonstrated that the double mutant W111A/F483K displayed the highest activity (370% of the WT). Our results indicated that the activity of LuxC significantly affects the bacterial bioluminescence reaction. Finally, we expressed this mutated lux operon in Escherichia coli but observed that the in vivo concentrations of ATP and NADPH limited the enzyme activity; thus, we conclude that the luminous intensity mainly depends on the level of metabolic energy.