RESUMO
A practical metal-free and additive-free approach for the synthesis of 6/7/8-membered oxacyclic ketone-fused isoxazoles/isoxazolines tetracyclic or tricyclic structures is reported through Csp3-H bond radical nitrile oxidation and the intramolecular cycloaddition of alkenyl/alkynyl-substituted aryl methyl ketones. This convenient approach enables the simultaneous formation of isoxazole/isoxazoline and 6/7/8-membered oxacyclic ketones to form polycyclic architectures by using tert-butyl nitrite (TBN) as a non-metallic radical initiator and N-O fragment donor.
RESUMO
Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.
Assuntos
Quitosana , Micoses , Nanopartículas , Praguicidas , Triazóis , Animais , Quitosana/química , Peixe-Zebra , Nanopartículas/química , Meio Ambiente , Dióxido de Silício/química , Porosidade , Portadores de Fármacos/químicaRESUMO
Cold acclimation is a complex biological process leading to the development of freezing tolerance in plants. In this study, we demonstrated that cold-induced expression of protease inhibitor FmASP in a Citrus-relative species kumquat [Fortunella margarita (Lour.) Swingle] contributes to its freezing tolerance by minimizing protein degradation. Firstly, we found that only cold-acclimated kumquat plants, despite extensive leaf cellular damage during freezing, were able to resume their normal growth upon stress relief. To dissect the impact of cold acclimation on this anti-freezing performance, we conducted protein abundance assays and quantitative proteomic analysis of kumquat leaves subjected to cold acclimation (4°C), freezing treatment (-10°C) and post-freezing recovery (25°C). FmASP (Against Serine Protease) and several non-specific proteases were identified as differentially expressed proteins induced by cold acclimation and associated with stable protein abundance throughout the course of low-temperature treatment. FmASP was further characterized as a robust inhibitor of multiple proteases. In addition, heterogeneous expression of FmASP in Arabidopsis confirmed its positive role in freezing tolerance. Finally, we proposed a working model of FmASP and illustrated how this extracellular-localized protease inhibitor protects proteins from degradation, thereby maintaining essential cellular function for post-freezing recovery. These findings revealed the important role of protease inhibition in freezing response and provide insights on how this role may help develop new strategies to enhance plant freezing tolerance.
RESUMO
Asion corn borer (Ostrinia furnacalis (Guenee)) is one of the most important factors affecting the normal growth and yield of corn. However, chemical control methods currently in use cause severe pollution. In the present study, aminated mesoporous silica nanoparticles (MSNs-NH2) and polylactic acid (PLA) were used as the carrier and capping agent respectively to construct an insect gut microenvironment nano-response system that loaded spinosad, a biopesticide used to control O. furnacalis. The resulting spinosad@MSNs-PLA demonstrated high loading capacity (38.6 %) and improved photostability of spinosad. Moreover, this delivery system could intelligently respond to the intestinal microenvironment of the corn borer's gut and achieve the smart release of spinosad. Compared with the conventional pesticide, spinosad@MSNs-PLA exhibited superior efficacy in controlling the O. furnacalis and could uptake and transport in maize plants without adverse effects on their growth. Furthermore, the toxicity of spinosad@MSNs-PLA on zebrafish was reduced by over 50 times. The prepared spinosad@MSNs-PLA has great potential and could be widely applied in agricultural production in the future. This approach could improve the utilization of pesticide and reduce environmental pollution. In addition, MSNs-PLA nano vectors provide new ideas for the control of other borer pests.
Assuntos
Nanopartículas , Praguicidas , Animais , Zea mays , Dióxido de Silício , Peixe-Zebra , Poliésteres , PorosidadeRESUMO
Oxidative stress induced by amyloid-ß (Aß) has been considered as one of the important mechanisms in the development of Alzheimer disease (AD). The inhibition of endogenous antioxidant Nrf2 signaling in the brain of AD patients aggravates the oxidative damage, however, the causes of Nrf2 signaling inhibition are unclear. It is reported that smallubiquitin-like modification (SUMOylation) is involved in the process of oxidative injury. To investigate whether and how SUMOylation was involved in the inhibition of Nrf2 signaling pathway induced by Aß, Aß intrahippocampal injection rat model and Aß treated SH-SY5Y cell model were used in the current study. Small interfering RNA and lentivirus transfection were used to intervene SUMOylation, and the level of SUMOylation was assessed by immunoprecipitation. The present in vivo and in vitro studies revealed that SUMOylation levels of Nrf2 and MafF, as well as the overall SUMOylation level were reduced under long-term Aß insult. Meanwhile, the binding of Nrf2 to MafF was decreased, accompanied by low interaction with antioxidant response element (ARE) area of gene. Down-regulation of SUMO protein exacerbated the Aß-induced inhibition of Nrf2 signaling pathway, while, enhancement of SUMOylation of Nrf2 and MafF by overexpression of Ubc9 reversed this process. These results imply that reduction in SUMOylation induced by Aß contributed to the inhibition of Nrf2 signaling, and SUMOylation might be a potential therapeutic target of AD.
Assuntos
Doença de Alzheimer , Neuroblastoma , Humanos , Ratos , Animais , Fator 2 Relacionado a NF-E2/metabolismo , Sumoilação , Peptídeos beta-Amiloides/metabolismo , Estresse Oxidativo , Doença de Alzheimer/metabolismo , Transdução de SinaisRESUMO
Chinese Herbal Medicines (CHMs) can be identified by experts according to their odors. However, the identification of these medicines is subjective and requires long-term experience. The samples of Acanthopanacis Cortex and Periplocae Cortex used were dried cortexes, which are often confused in the market due to their similar appearance, but their chemical composition and odor are different. The clinical use of the two herbs is different, but the phenomenon of being confused with each other often occurs. Therefore, we used an electronic nose (E-nose) to explore the differences in odor information between the two species for fast and robust discrimination, in order to provide a scientific basis for avoiding confusion and misuse in the process of production, circulation and clinical use. In this study, the odor and volatile components of these two medicinal materials were detected by the E-nose and by gas chromatography-mass spectrometry (GC-MS), respectively. An E-nose combined with pattern analysis methods such as principal component analysis (PCA) and partial least squares (PLS) was used to discriminate the cortex samples. The E-nose was used to determine the odors of the samples and enable rapid differentiation of Acanthopanacis Cortex and Periplocae Cortex. GC-MS was utilized to reveal the differences between the volatile constituents of Acanthopanacis Cortex and Periplocae Cortex. In all, 82 components including 9 co-contained components were extracted by chromatographic peak integration and matching, and 24 constituents could be used as chemical markers to distinguish these two species. The E-nose detection technology is able to discriminate between Acanthopanacis Cortex and Periplocae Cortex, with GC-MS providing support to determine the material basis of the E-nose sensors' response. The proposed method is rapid, simple, eco-friendly and can successfully differentiate these two medicinal materials by their odors. It can be applied to quality control links such as online detection, and also provide reference for the establishment of other rapid detection methods. The further development and utilization of this technology is conducive to the further supervision of the quality of CHMs and the healthy development of the industry.
Assuntos
Nariz Eletrônico , Compostos Orgânicos Voláteis , Cromatografia Gasosa-Espectrometria de Massas/métodos , Análise Multivariada , Controle de Qualidade , Odorantes/análise , Compostos Orgânicos Voláteis/análiseRESUMO
Tumour cell metabolic plasticity is essential for tumour progression and therapeutic responses, yet the underlying mechanisms remain poorly understood. Here, we identify Prospero-related homeobox 1 (PROX1) as a crucial factor for tumour metabolic plasticity. Notably, PROX1 is reduced by glucose starvation or AMP-activated protein kinase (AMPK) activation and is elevated in liver kinase B1 (LKB1)-deficient tumours. Furthermore, the Ser79 phosphorylation of PROX1 by AMPK enhances the recruitment of CUL4-DDB1 ubiquitin ligase to promote PROX1 degradation. Downregulation of PROX1 activates branched-chain amino acids (BCAA) degradation through mediating epigenetic modifications and inhibits mammalian target-of-rapamycin (mTOR) signalling. Importantly, PROX1 deficiency or Ser79 phosphorylation in liver tumour shows therapeutic resistance to metformin. Clinically, the AMPK-PROX1 axis in human cancers is important for patient clinical outcomes. Collectively, our results demonstrate that deficiency of the LKB1-AMPK axis in cancers reactivates PROX1 to sustain intracellular BCAA pools, resulting in enhanced mTOR signalling, and facilitating tumourigenesis and aggressiveness.
Assuntos
Proteínas Quinases Ativadas por AMP , Neoplasias , Humanos , Aminoácidos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Transformação Celular Neoplásica , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Serina-Treonina Quinases TOR , Fatores de Transcrição/metabolismoRESUMO
The study aimed to investigate the learning motivation of freshmen from a university in Northwest China, which can supply a reference for improving their learning quality and objectives. Data were collected from 800 freshmen of different majors with a learning motivation questionnaire. Differences in learning motivation between different majors, genders, regions, and students are studied. The results show that gender, seeking knowledge orientation, and material pursuit have significant effects on students' learning motivation. The gender had a significant impact on personal achievement and the only child or not had an obvious effect on material pursuit, while other factors had no obvious difference in gender, regional, and only child or not, while other factors on the gender, regional, and whether the one-child had no obvious difference. According to the results of the research, measures to improve learning motivation are proposed. Our research results provide a reference for improving learning attitude and the quality of universities.
RESUMO
The study aimed to investigate the relationship among perceived stress, state-trait anxiety, and sleep quality of graduates to provide a reference for improving their psychological status and attitude adjustment of job-searching during the COVID-19 pandemic. The research was conducted in a descriptive cross-sectional online survey between May 2020 and August 2020. The data were collected from 1,200 participants by using the personal information form prepared by the researchers in line with the literature, the Perceived Stress Scale, the State-Trait Anxiety Inventory, and the Pittsburgh Sleep Quality Index (PSQI). Among the surveyed participants, 47.67% were female, and 10.92% were medical students. The mean perceived stress, state anxiety, trait anxiety, and sleep quality were moderate and found as 31.4±6.69, 46.67±5.80, 49.45±5.54, and 5.94±2.47, respectively. The detection rates of state anxiety and trait anxiety were 48.63 and 49.50%, respectively. There was no significant difference in the detection rate of state anxiety and trait anxiety among different genders and majors (p >0.05). The detection rate of state anxiety and trait anxiety of rural family students was higher than that of urban family students (p <0.01). The score on the PSQI was positively associated with the scores on the perceived stress, state anxiety, and trait anxiety scales (p <0.001 for each model). Sleep quality was associated with increased perceived stress, state anxiety, and trait anxiety among graduates in China. Collectively, the study revealed the relationship between perceived stress, state-trait anxiety, and sleep quality among university graduates in China during the COVID-19 pandemic. Our results offer novel practical implications for all circles of the society to ensure students' health under the context of the COVID-19 epidemic.
RESUMO
Magnesium (Mg) and its alloys have attached more and more attention because of their potential as a new type of biodegradable metal materials. In this work, AZ31/ZrO2 nanocomposites with good uniformity were prepared successfully by friction stir processing (FSP). The scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to characterize the microstructure of the composites. The mechanical properties, electrochemical corrosion properties and biological properties were evaluated. In addition, the effect of reinforced particles (ZrO2) on the microstructure and properties of the composite was studied comparing with FSP AZ31 Mg alloy. The results show that compared with the base metal (BM), the AZ31/ZrO2 composite material achieves homogenization, densification, and grain refinement after FSP. The combination of dynamic recrystallization and ZrO2 particles leads to grain refinement of Mg alloy, and the average grain size of AZ31/ZrO2 composites is 3.2 µm. After FSP, the c-axis of grain is deflected under the compression stress of shoulder and the shear stress of pin. The ultimate tensile strength (UTS) and yield strength (YS) of BM were 283 and 137 MPa, respectively, the UTS and YS of AZ31/ZrO2 composites were 427 and 217 MPa, respectively. The grain refinement and Orowan strengthening are the major strengthening mechanisms. Moreover, the corrosion resistance in simulated body fluid of Mg alloy is improved by grain refinement and the barrier effect of ZrO2.
RESUMO
BACKGROUND AND AIMS: The wide prevalence of chemoresistance and compromised early diagnosis of gallbladder cancer (GBC) has led to poor patient prognosis, requiring sustained efforts for the identification of effective biomarkers and therapeutic intervention. Ceramides have emerged as intracellular signaling molecules linked to tumorigenesis and therapeutic response in cancers. However, the clinical relevance of ceramides with GBC has not been investigated. APPROACH AND RESULTS: In the present study, we revealed aberrant gene expressions (e.g., serine palmitoyltransferase 1 [SPTLC1] and ceramide synthase 2 [CERS2]) of de novo ceramide biosynthesis and length-specific ceramide production in GBC tissues. Analyses of serum ceramide pattern in healthy controls, gallbladder stone, and GBC patients identified C24-Ceramide as a potential diagnostic biomarker for patients with GBC. Importantly, elevation of SPTLC1, CERS2, and its product, C24-Ceramide, was associated with tumor staging, distal metastasis, and worse prognosis. In line with this, C24 -Ceramide promoted GBC cell proliferation and migration in vitro and in vivo. Mechanistically, C24-Ceramide directly bound to phosphatidylinositol 5-phosphate 4-kinase type-2 gamma (PIP4K2C), a regulator of mammalian target of rapamycin (mTOR), to facilitate mTOR complex formation and activation. C6-Ceramide, an analogue of natural ceramide, competed with C24-Ceramide for PIP4K2C binding, thereby abrogating C24-Ceramide-mediated mTOR signaling activation and oncogenic activity. Furthermore, stimulation with C6-Ceramide significantly suppressed the proliferative and metastatic capacity of GBC cells in vitro and in vivo, which was dependent on PIP4K2C. CONCLUSIONS: Our findings highlight the clinical relevance of ceramide metabolism with GBC progression and identify C24-Ceramide as a diagnostic biomarker for GBC. We propose that PIP4K2C is indispensable for C6-Ceramide as a potential therapeutic intervention for GBC through a direct competition with C24-Ceramide.
Assuntos
Biomarcadores Tumorais/metabolismo , Ceramidas/metabolismo , Neoplasias da Vesícula Biliar/patologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Animais , Feminino , Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/diagnóstico , Neoplasias da Vesícula Biliar/genética , Neoplasias da Vesícula Biliar/mortalidade , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Estadiamento de Neoplasias , Prognóstico , Serina C-Palmitoiltransferase/metabolismo , Esfingosina N-Aciltransferase/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Autophagy, an evolutionarily conserved mechanism to remove redundant or dangerous cellular components, plays an important role in innate immunity and defense against pathogens, which, in turn, can regulate autophagy to establish infection within a host. However, for Entamoeba histolytica, an intestinal protozoan parasite causing human amoebic colitis, the interaction with the host cell autophagy mechanism has not been investigated. In this study, we found that E. histolytica peroxiredoxin (Prx), an antioxidant enzyme critical for parasite survival during the invasion of host tissues, could activate autophagy in macrophages. The formation of autophagosomes in macrophages treated with recombinant Prx of E. histolytica for 24 h was revealed by immunofluorescence and immunoblotting in RAW264.7 cells and in mice. Prx was cytotoxic for RAW264.7 macrophages after 48-h treatment, which was partly attributed to autophagy-dependent cell death. RNA interference experiments revealed that Prx induced autophagy mostly through the toll-like receptor 4 (TLR4)-TIR domain-containing adaptor-inducing interferon (TRIF) pathway. The C-terminal part of Prx comprising 100 amino acids was the key functional domain to activate autophagy. These results indicated that Prx of E. histolytica could induce autophagy and cytotoxic effects in macrophages, revealing a new pathogenic mechanism activated by E. histolytica in host cells.
Assuntos
Autofagia , Entamoeba histolytica/metabolismo , Peroxirredoxinas/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Autofagossomos/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Peroxirredoxinas/química , Domínios Proteicos , Células RAW 264.7 , Transdução de Sinais , Receptor 4 Toll-Like/metabolismoRESUMO
Gallbladder cancer (GBC) is the common malignancy of the bile tract system with extremely poor clinical outcomes, owing to its metastatic property and intrinsic resistance to the first-line drugs. Although it is well-established that cholesterol abnormity contributes to gallstone formation, a leading risk factor for GBC, the link of cholesterol homeostasis with GBC has not been investigated. The present study systematically examined the genes implicated in cholesterol homeostasis, and revealed altered gene expressions of de novo cholesterol biosynthesis and sterol sulfonation (SULT2B1), reduced bile acid synthesis (CYP7B1 and CYP39A1) and impaired sterol efflux (ABCA1, ABCG5, LCAT, and CETP) in GBC tissues. Suppression of cholesterol biosynthesis by lovastatin inhibited GBC cell proliferation possibly through attenuating the DNA repair process. Further investigation revealed lovastatin sensitized GBC cells to cisplatin-induced apoptosis and suppressed the activation of CHK1, CHK2, and H2AX during DNA damage response. By using chemically distinct statins, HMGCR depletion or supplementing mevalonate, the product of HMGCR, we showed the inhibitory effects on DNA repair process of lovastatin were due to the blockage of the mevalonate pathway. Subcutaneous xenograft mice model suggested lovastatin promoted the therapeutic efficacy of cisplatin, and significantly prolonged the survival times of tumor-bearing mice. Moreover, HMGCR ablation repressed tumor growth in vivo, which can be rescued partially by restored expression of HMGCR, suggesting the on-target effects of lovastatin. Therefore, our study provides the clinical relevance of cholesterol homeostasis with GBC progression, and highlights a novel intervention of combined use of lovastatin and cisplatin for GBC.
Assuntos
Colesterol/genética , Cisplatino/efeitos adversos , Neoplasias da Vesícula Biliar/tratamento farmacológico , Cálculos Biliares/tratamento farmacológico , Transportador 1 de Cassete de Ligação de ATP/genética , Membro 5 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Apoptose/efeitos dos fármacos , Colesterol/biossíntese , Proteínas de Transferência de Ésteres de Colesterol/genética , Cisplatino/farmacologia , Família 7 do Citocromo P450/genética , Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Feminino , Neoplasias da Vesícula Biliar/genética , Neoplasias da Vesícula Biliar/patologia , Cálculos Biliares/genética , Cálculos Biliares/patologia , Xenoenxertos , Humanos , Masculino , Camundongos , Fosfatidilcolina-Esterol O-Aciltransferase/genética , Fatores de Risco , Esteroide Hidroxilases/genética , Sulfotransferases/genéticaRESUMO
Hepatitis B virus (HBV) envelopes as well as empty subviral particles carry in their lipid membranes the small (S), middle (M), and large (L) surface proteins, collectively known as hepatitis B surface antigen (HBsAg). Due to their common S domain all three proteins share a surface-exposed hydrophilic antigenic loop (AGL) with a complex disulfide bridge-dependent structure. The AGL is critical for HBV infectivity and virion secretion, and thus represents a major target for neutralizing antibodies. Previously, a human monoclonal antibody (mAb) targeting a conformational epitope in the AGL, IgG12, exhibited 1000-fold higher neutralizing activity than hepatitis B immune globulin (HBIG). Here we designed a single-chain variable fragment (scFv) homolog of IgG12, G12-scFv, which could be efficiently produced in soluble form in the cytoplasm of E. coli SHuffle cells. Independent in vitro assays verified specific binding of G12-scFv to a conformational S epitope shared with IgG12. Despite 20-fold lower affinity, G12-scFv but not an irrelevant scFv potently neutralized HBV infection of susceptible hepatoma cells (IC50â¯=â¯1.8â¯nM). Strikingly, low concentrations of G12-scFv blocked virion secretion from HBV producing cells (IC50â¯=â¯1.25â¯nM) without disturbing intracellular viral replication, whereas extracellular HBsAg was reduced only at >100-fold higher though still nontoxic concentration. The inhibitory effects correlated with S binding specificity and presumably also G12-scFv internalization into cells. Together these data suggest G12-scFv as a highly specific yet easily accessible novel tool for basic, diagnostic, and possibly future therapeutic applications.
Assuntos
Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/efeitos dos fármacos , Anticorpos de Cadeia Única/imunologia , Anticorpos de Cadeia Única/farmacologia , Vírion/efeitos dos fármacos , Anticorpos Neutralizantes , Escherichia coli , Células Hep G2 , Vírus da Hepatite B/fisiologia , Humanos , Concentração Inibidora 50 , Anticorpos de Cadeia Única/biossíntese , Vírion/fisiologia , Replicação Viral/efeitos dos fármacosRESUMO
BACKGROUND: Fine ambient particle matter (PM2.5) induces inflammatory lung injury; however, whether intratracheal administration of PM2.5 increases pulmonary polymorphonuclear leukocyte (PMN) infiltration, the mechanism of infiltration, and if these cells exacerbate PM2.5-induced lung injury are unknown. METHODS: Using 32,704 subjects, the association between blood PMNs and ambient PM2.5 levels on the previous day was retrospectively analyzed. Neutropenia was achieved by injecting mice with PMN-specific antibodies. Inhibition of PMN infiltration was achieved by pretreating PMNs with soluble vascular cell adhesion molecule-1 (sVCAM-1). The effects of PMNs on PM2.5-induced lung injury and endothelial dysfunction were observed. RESULT: Short-term PM2.5 (> 75 µg/m3 air) exposure increased the PMN/white blood cell ratio and the PMN count in human peripheral blood observed during routine examination. A significant number of PM2.5-treated PMNs was able to bind sVCAM-1. In mice, intratracheally-instilled PM2.5 deposited in the alveolar space and endothelial cells, which caused significant lung edema, morphological disorder, increased permeability of the endothelial-alveolar epithelial barrier, and PMN infiltration with increased VCAM-1 expression. Depletion of circulatory PMNs inhibited these adverse effects. Replenishment of untreated PMNs, but not those pretreated with soluble VCAM-1, restored lung injury. In vitro, PM2.5 increased VCAM-1 expression and endothelial and epithelial monolayer permeability, and promoted PMN adhesion to, chemotaxis toward, and migration across these monolayers. PMNs, but not those pretreated with soluble VCAM-1, exacerbated these effects. CONCLUSION: VCAM-1-mediated PMN infiltration was essential for a detrimental cycle of PM2.5-induced inflammation and lung injury. Results suggest that drugs that inhibit PMN function might prevent acute deterioration of chronic pulmonary and cardiovascular diseases triggered by PM2.5.
Assuntos
Lesão Pulmonar/induzido quimicamente , Pulmão/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Material Particulado , Edema Pulmonar/induzido quimicamente , Molécula 1 de Adesão de Célula Vascular/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Epiteliais Alveolares/imunologia , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Animais , Permeabilidade Capilar , Adesão Celular , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Células Endoteliais da Veia Umbilical Humana/imunologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Pulmão/imunologia , Pulmão/patologia , Lesão Pulmonar/imunologia , Lesão Pulmonar/metabolismo , Lesão Pulmonar/patologia , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Neutropenia/imunologia , Neutropenia/metabolismo , Neutropenia/patologia , Neutrófilos/imunologia , Neutrófilos/patologia , Tamanho da Partícula , Edema Pulmonar/imunologia , Edema Pulmonar/metabolismo , Edema Pulmonar/patologia , Estudos Retrospectivos , Molécula 1 de Adesão de Célula Vascular/imunologia , Adulto JovemRESUMO
BACKGROUND: Acanthamoeba spp. can cause serious human infections, including Acanthamoeba keratitis, granulomatous amoebic encephalitis and cutaneous acanthamoebiasis. Cysteine biosynthesis and the L-serine metabolic pathway play important roles in the energy metabolism of Acanthamoeba spp. However, no study has confirmed the functions of cysteine synthase (AcCS) in the cysteine pathway and phosphoglycerate dehydrogenase (AcGDH) or phosphoserine aminotransferase (AcSPAT) in the non-phosphorylation serine metabolic pathway of Acanthamoeba. METHODS: The AcCS, AcGDH and AcSPAT genes were amplified by PCR, and their recombinant proteins were expressed in Escherichia coli. Polyclonal antibodies against the recombinant proteins were prepared in mice and used to determine the subcellular localisation of each native protein by confocal laser scanning microscopy. The enzymatic activity of each recombinant protein was also analysed. Furthermore, each gene expression level was analysed by quantitative PCR after treatment with different concentrations of cysteine or L-serine. RESULTS: The AcCS gene encodes a 382-amino acid protein with a predicted molecular mass of 43.1 kDa and an isoelectric point (pI) of 8.11. The AcGDH gene encodes a 350-amino acid protein with a predicted molecular mass of 39.1 kDa and a pI of 5.51. The AcSPAT gene encodes a 354-amino acid protein with a predicted molecular mass of 38.3 kDa and a pI of 6.26. Recombinant AcCS exhibited a high cysteine synthesis activity using O-acetylserine and Na2S as substrates. Both GDH and SPAT catalysed degradation, rather than synthesis, of serine. Exogenous L-serine or cysteine inhibited the expression of all three enzymes in a time- and dose-dependent manner. CONCLUSIONS: This study demonstrated that AcCS participates in cysteine biosynthesis and serine degradation via the non-phosphorylation serine metabolic pathway, providing a molecular basis for the discovery of novel anti-Acanthamoeba drugs.
Assuntos
Acanthamoeba castellanii/enzimologia , Acanthamoeba castellanii/genética , Cisteína/metabolismo , Redes e Vias Metabólicas/genética , Serina/metabolismo , Acanthamoeba castellanii/efeitos dos fármacos , Acanthamoeba castellanii/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Cisteína/biossíntese , Cisteína/farmacologia , Cisteína Sintase/genética , Cisteína Sintase/imunologia , Cisteína Sintase/metabolismo , Sistemas de Liberação de Medicamentos , Escherichia coli/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Glicólise , Camundongos , Microscopia Confocal , Fosfoglicerato Desidrogenase/genética , Fosfoglicerato Desidrogenase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Serina/biossíntese , Serina/farmacologia , Desidrogenase do Álcool de Açúcar/genética , Desidrogenase do Álcool de Açúcar/imunologia , Desidrogenase do Álcool de Açúcar/metabolismo , Transaminases/genética , Transaminases/imunologia , Transaminases/metabolismoRESUMO
Sodium-ion batteries (SIBs) attract more attention because of sodium's abundant availability, affordable price, and potential to be an effective anode material. Meanwhile, carbon-based materials provide the most promising anode materials. Because of the large radius of sodium ions, SIBs do not exhibit favorable electrochemical performance. Introducing heteroatoms into the carbon-lattice is an effective strategy to enlarge the interlayer space of carbon-based materials which can improve carbon's electrochemical performance. In addition, anode materials with a surface-induced capacitive process can enhance the SIB's electrochemical performance because its capacitive process increases the kinetics of ion diffusion. Here, we describe an SIB's anode material containing nitrogen and sulfur co-doped graphene sheets [denoted as poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT)/reduced graphene oxide (RGO)] which are synthesized via carbonization of PDMcT polymerized on the surface of GO. PDMcT/RGO exhibited high capacities (240 mA h g-1 at 500 mA g-1), improved rate performance (144 mA h g-1 at 10 A g-1), and good cycling stability (153 mA h g-1 after 5000 cycles at 5000 mA g-1). These unique results are attributed to the enlarged interlayer spacing and electronic conductivity from the heteroatoms which facilitate the sodium ion's insertion and electron transport. These results represent that PDMcT/RGO is a great potential anode material for SIBs.
RESUMO
In the present study, a new analogue of pyrrolezanthine (1) was isolated from the roots of Reynoutria ciliinervis (Nakai) Moldenke. Its structure was elucidated mainly by NMR, HR-ESI-MS and the single-crystal X-ray diffraction spectroscopic data. Meanwhile, the antimicrobial activity of compound 1 was measured, it exhibited potent antifungal activity against Sclerotinia sclerotiorum with MIC value of 31.2 µg/mL.
Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Polygonaceae/química , Pirróis/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Ascomicetos/efeitos dos fármacos , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos/métodos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Raízes de Plantas/química , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
Acanthamoeba spp. can be parasitic in certain situations and are responsible for serious human infections, including Acanthamoeba keratitis, granulomatous amoebic encephalitis, and cutaneous acanthamoebiasis. We analyzed the fatty acid composition of Acanthamoeba castellanii trophozoites and tested the inhibitory activity of the main fatty acids, oleic acid and arachidonic acid, in vitro. Oleic acid markedly inhibited the growth of A. castellanii, with trophozoite viability of 57.4% at a concentration of 200 µM. Caspase-3 staining and annexin V assays showed that apoptotic death occurred in A. castellanii trophozoites. Quantitative PCR and dot blot analysis showed increased levels of metacaspase and interleukin-1ß converting enzyme, which is also an indication of apoptosis. In contrast, arachidonic acid showed negligible inhibition of growth of A. castellanii trophozoites. Stimulated expression of Atg3, Atg8 and LC3A/B genes and monodansylcadaverine labeling suggested that oleic acid induces apoptosis by triggering autophagy of trophozoites.
Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Ácido Oleico/farmacologia , Trofozoítos/efeitos dos fármacos , Acanthamoeba castellanii/genética , Autofagia , Caspase 3/genéticaRESUMO
In order to explore genetic basis for the biosynthesis of secondary metabolism,the transcriptome of Cornus officinalis was sequenced by the new generation of high-throughput sequencing technology,A total of 96 032 unigenes were assembled with an average length of 590.53 bp. Among them, 35 478 unigenes were annotated in the public databases NR,Swissprot,COG,GO,KOG,Pfam and KEGG. Based on the assignment of KEGG pathway, 84 involved in ridoid biosynthesis and 487 unigenes involved in others secondary metabolites biosynthesis were found. Additionally,53 unigenes and 72 unigenes were predicted to have potential functions of cytochome P450 and UDP- glycosyltransferases based on the annotation result, which may encode responsible for secondary metabolites modification. This study was the first comprehensive transcriptome analysis for C. officinalis, and the candidate genes involved in the biosynthesis of secondary metabolites were obtained. The transcriptome data constitutes a much more abundant genetic resource that can be utilized to benefit further molecular biology studies on C. officinalis.