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Listeria monocytogenes (LM) is a Gram-positive (G+) bacterium that secretes nanoscale membrane vesicles (MVs). LM MVs comprise various bacterial components and may have potential as an antigen or drug-delivery vehicle; however, the low yield of the LM MVs limits related research. G+-bacterial MVs germinate from the bacterial plasma membrane and must pass through a thick crosslinked peptidoglycan layer for release. Herein, we aimed to increase the release of MVs by reducing the degree of crosslinking of peptidoglycan. We knocked out two genes related to the longitudinal crosslinking of peptidoglycan, dal and dat, and supplemented the knocked-out dal gene through plasmid expression to obtain a stably inherited recombinant strain LMΔdd::pCW633. The structure, particle size, and main protein components of MVs secreted by this recombinant strain were consistent with those secreted from the wild strain, but the yield of MVs was considerably increased (p < 0.05). Furthermore, Listeria ivanovii (LI) was found to secrete MVs that differed in the composition of the main proteins compared with those of LM MVs. The abovementioned method was also feasible for promoting the secretion of MVs from the attenuated LM strain and LI wild-type and attenuated strains. Our study provides a new method to increase the secretion of MVs derived from Listeria that could be extended to other G+ bacteria.
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Rapid biological detection of pathogen micro-organisms has attracted much attention for practical biomedical applications. Despite the development in this field, it is still challenging to achieve simple and rapid biological detection using the microfluidic method. Herein, we propose a novel strategy of biological detection that combines precise detection control of the capillary microfluidic chip and versatile manipulation of magnetic beads. The microfluidic chip was fabricated via laser cutting, which utilized capillary pressure to realize rapid passive injection of liquid samples. Under an external magnetic field, the aptamer-modified magnetic beads were actuated to mix with Vibrio parahaemolyticus (V. parahaemolyticus) and its nucleic acid in the capillary microfluidic chip for rapid selective capture and detection, which could be achieved within 40 min. The experimental results demonstrated that V. parahaemolyticus could be captured using on-chip immunomagnetic beads with a high efficiency and significantly enhanced detection value. Due to these superior performances, the capillary microfluidic system, based on the manipulation of magnetic beads, demonstrated great potential for automatic biological detection.
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Rosmarinic acid (RA), Tanshinone IIA (Tan IIA), and Salvianolic acid B (Sal B) are crucial compounds found in Salvia miltiorrhiza. Quickly predicting these components can aid in ensuring the quality of S. miltiorrhiza. Spectral preprocessing and variable selection are essential processes in quantitative analysis using near infrared spectroscopy (NIR). A novel hybrid variable selection approach utilizing iVISSA was employed in this study to enhance the quantitative measurement of RA, Tan IIA, and Sal B contents in S. miltiorrhiza. The spectra underwent 108 preprocessing approaches, with the optimal method being determined as orthogonal signal correction (OSC). iVISSA was utilized to identify the intervals (feature bands) that were most pertinent to the target chemical. Various methods such as bootstrapping soft shrinkage (BOSS), competitive adaptive reweighted sampling (CARS), genetic algorithm (GA), variable combination population analysis (VCPA), successive projections algorithm (SPA), iteratively variable subset optimization (IVSO), and iteratively retained informative variables (IRIV) were used to identify significant feature variables. PLSR models were created for comparison using the given variables. The results fully demonstrated that iVISSA-SPA calibration model had the best comprehensive performance for Tan IIA, and iVISSA-BOSS had the best comprehensive performance for RA and Sal B, and correlation coefficients of cross-validation (R2cv), root mean square errors of cross-validation (RMSECV), correlation coefficients of prediction (R2p), and root mean square errors of prediction (RMSEP) were 0.9970, 0.0054, 0.9990 and 0.0033, 0.9992, 0.0016, 0.9961 and 0.0034, 0.9998, 0.0138, 0.9875 and 0.1090, respectively. The results suggest that NIR spectroscopy, along with PLSR and a hybrid variable selection method using iVISSA, can be a valuable tool for quickly quantifying RA, Sal B, and Tan IIA in S. miltiorrhiza.
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Abietanos , Algoritmos , Benzofuranos , Cinamatos , Depsidos , Ácido Rosmarínico , Salvia miltiorrhiza , Espectroscopía Infrarroja Corta , Salvia miltiorrhiza/química , Espectroscopía Infrarroja Corta/métodos , Depsidos/análisis , Abietanos/análisis , Benzofuranos/análisis , Cinamatos/análisis , Análisis de los Mínimos CuadradosRESUMEN
Objective: To summarize the status and characteristics of the available evidence, research gaps, and future research priorities for preventing falls in stroke patients through balance training. Methods: We used a scoping review framework. A systematic search of PUBMED, Embase, and Cochrane databases for main articles was conducted. Our study only included articles that on balance training and fall-related indicators in stroke patients. Two researchers independently screened the literature according to the inclusion and exclusion criteria. The data of demographic, clinical characteristics, intervention, sample, and outcome indicators were extracted. The characteristics and limitations of the included literature were comprehensively analyzed. Results: Of the 1,058 studies, 31 were included. The methods of balance training include regular balance training, Tai Chi, Yoga, task balance training, visual balance training, multisensory training, aquatic balance training, perturbation-based balance training, cognitive balance training, system-based balance training, and robot-assisted balance training. The commonly used outcome measures include clinical balance test, such as Berg balance scale (BBS), Timed Up-and-Go Test (TUG), Fall Risk Index assessment (FRI), Fall Efficacy Scale score (FES), and instrumented balance tests. Conclusion: This scoping review summarizes the existing primary research on preventing falls in stroke patients by balance training. Based on the summary of the existing evidence, the characteristics of balance training and their relation to falls in stroke patients were found. The future researches should explore how to develop personalized training program, the sound combination of various balance training, to more effectively prevent falls.
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Parkinson's disease (PD) is a common neuron degenerative disease among the old, characterized by uncontrollable movements and an impaired posture. Although widely investigated on its pathology and treatment, the disease remains incompletely understood. Single-cell RNA sequencing (scRNA-seq) has been applied to the area of PD, providing valuable data for related research. However, few works have taken deeper insights into the causes of neuron death and cell-cell interaction between the cell types in the brain. Our bioinformatics analyses revealed necroptosis-related genes (NRGs) enrichment in neuron degeneration and selecting the cells by NRGs levels showed two subtypes within the main degenerative cell types in the midbrain. NRG-low subtype was largely replaced by NRG-high subtype in the patients, indicating the striking change of cell state related to necroptosis in PD progression. Moreover, we carried out cell-cell interaction analyses between cell types and found that microglia (MG)'s interaction strength with glutamatergic neuron (GLU), GABAergic neuron (GABA), and dopaminergic neuron (DA) was significantly upregulated in PD. Also, MG show much stronger interaction with NRG-high subtypes and a stronger cell killing function in PD samples. Additionally, we identified CLDN11 as a novel interaction pattern specific to necroptosis neurons and MG. We also found LEF1 and TCF4 as key transcriptional regulators in neuron degeneration. These findings suggest that MG were significantly overactivated in PD patients to clear abnormal neurons, especially the NRG-high cells, explaining the neuron inflammation in PD. Our analyses provide insights into the causes of neuron death and inflammation in PD from single-cell resolution, which could be seriously considered in clinical trials.
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Six transmembrane epithelial antigen of the prostate (STEAP) 1-4 are membrane-embedded hemoproteins that chelate a heme prosthetic group in a transmembrane domain (TMD). STEAP2-4, but not STEAP1, have an intracellular oxidoreductase domain (OxRD) and can mediate cross-membrane electron transfer from NADPH via FAD and heme. However, it is unknown whether STEAP1 can establish a physiologically relevant electron transfer chain. Here, we show that STEAP1 can be reduced by reduced FAD or soluble cytochrome b5 reductase that serves as a surrogate OxRD, providing the first evidence that STEAP1 can support a cross-membrane electron transfer chain. It is not clear whether FAD, which relays electrons from NADPH in OxRD to heme in TMD, remains constantly bound to the STEAPs. We found that FAD reduced by STEAP2 can be utilized by STEAP1, suggesting that FAD is diffusible rather than staying bound to STEAP2. We determined the structure of human STEAP2 in complex with NADP+ and FAD to an overall resolution of 3.2 Å by cryo-electron microscopy and found that the two cofactors bind STEAP2 similarly as in STEAP4, suggesting that a diffusible FAD is a general feature of the electron transfer mechanism in the STEAPs. We also demonstrated that STEAP2 reduces ferric nitrilotriacetic acid (Fe3+-NTA) significantly slower than STEAP1 and proposed that the slower reduction is due to the poor Fe3+-NTA binding to the highly flexible extracellular region in STEAP2. These results establish a solid foundation for understanding the function and mechanisms of the STEAPs.
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Electrones , Próstata , Masculino , Humanos , NADP/metabolismo , Microscopía por Crioelectrón , Próstata/metabolismo , Oxidorreductasas/metabolismo , Hemo/metabolismo , Antígenos de NeoplasiasRESUMEN
BACKGROUND: Increasing evidence suggests that repairing the damaged intestinal epithelial barrier and restoring its function is the key to solving the problem of prolonged ulcerative colitis. Previous studies have shown that paeonol (pae) can alleviate colitis by down-regulating inflammatory pathways. In addition, pae also has a certain effect on regulating intestinal flora. However, it remains unclear whether pae can play a role in repairing the intestinal barrier and whether there is a relationship between the therapeutic effect and the gut microbiota. PURPOSES: The aim of this study is to investigate the effect of pae on intestinal barrier repair in UC mice and how the gut microbiota plays a part in it. STUDY DESIGN AND METHODS: The therapeutic effect of pae was evaluated in a 3% DSS-induced UC mouse model. The role of pae in repairing the intestinal barrier was evaluated by detecting colonic cupped cells by Alcian blue staining, the expression of colonic epithelial tight junction protein by immunofluorescence and western blot, and the proportion of IL-22+ILC3 cells in the lamina propria lymphocytes by flow cytometry. Subsequently, 16S rRNA sequencing was used to observe the changes in intestinal flora, GC-MS was used to detect the level of SCFAs, and qPCR was used to identify the abundance of Clostridium butyricum in the intestine to evaluate the effect of pae on the gut microbiota. The antibiotic-mediated depletion of the gut flora was then used to verify that pae depends on C. butyricum to play a healing role. Finally, non-targeted metabolomics was employed to investigate the potential pathways of pae regulating C. butyricum. RESULTS: Pae could improve intestinal microecological imbalance and promote the production of short-chain fatty acids (SCFAs). Most importantly, we identified C. butyricum as a key bacterium responsible for the intestinal barrier repair effect of pae in UC mice. Eradication of intestinal flora by antibiotics abolished the repair of the intestinal barrier and the promotion of SCFAs production by pae, while C. butyricum colonization could restore the therapeutic effects of pae in UC mice, which further confirmed that C. butyricum was indeed the "driver bacterium" of pae in UC treatment. Untargeted metabolomics showed that pae regulated some amino acid metabolism and 2-Oxocarboxylic acid metabolism in C. butyricum. CONCLUSIONS: Our study showed that the restoration of the impaired intestinal barrier by pae to alleviate colitis is associated with increased C. butyricum and SCFAs production, which may be a promising strategy for the treatment of UC.
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Clostridium butyricum , Colitis Ulcerosa , Colitis , Animales , Ratones , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , ARN Ribosómico 16S , Antibacterianos , Ácidos Grasos VolátilesRESUMEN
Members of the nucleobase/ascorbic acid transporter (NAT) gene family are found in all kingdoms of life. In mammals, the concentrative uptake of ascorbic acid (vitamin C) by members of the NAT family is driven by the Na+ gradient, while the uptake of nucleobases in bacteria is powered by the H+ gradient. Here, we report the structure and function of PurTCp, a NAT family member from Colwellia psychrerythraea. The structure of PurTCp was determined to 2.80 Å resolution by X-ray crystallography. PurTCp forms a homodimer, and each protomer has 14 transmembrane segments folded into a transport domain (core domain) and a scaffold domain (gate domain). A purine base is present in the structure and defines the location of the substrate binding site. Functional studies reveal that PurTCp transports purines but not pyrimidines and that purine binding and transport is dependent on the pH. Mutation of a conserved aspartate residue close to the substrate binding site reveals the critical role of this residue in H+-dependent transport of purines. Comparison of the PurTCp structure with transporters of the same structural fold suggests that rigid-body motions of the substrate-binding domain are central for substrate translocation across the membrane.
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Ácido Ascórbico , Purinas , Animales , Transporte Biológico , Purinas/metabolismo , Mutación , Sitios de Unión , Ácido Ascórbico/metabolismo , Mamíferos/metabolismoRESUMEN
Spatial localization ability is crucial for free-living animals to fit the environment. As shown by previous studies, planarians can be conditioned to discriminate directions. However, due to their simplicity and primitiveness, they had never been considered to have true spatial localization ability to retrieve locations of objects and places in the environment. Here, we introduce a light maze training paradigm to demonstrate that a planarian worm can navigate to a former recognized place from the start point, even if the worm is transferred into a newly produced maze. This finding identifies the spatial localization ability of planarians for the first time, which provides clues for the evolution of spatial learning. Since the planarians have a primitive brain with simple structures, this paradigm can also provide a simplified model for a detailed investigation of spatial learning.
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Planarias , Animales , Encéfalo , CabezaRESUMEN
Membrane vesicles (MVs) derived from Listeria monocytogenes (LM) have a natural nanoscale size and contain a variety of bacterial components. We speculated that LM MVs may be a novel delivery vector, but it is necessary to evaluate the safety and immunogenicity of LM MVs in vivo. Here, we isolated LM MVs and tested their safety and immunogenicity both in vitro and in vivo. The results showed that LM MVs stimulated RAW264.7 cells and DC2.4 cells to secrete the inflammatory cytokines IL-1ß, TNF-α, IL-6 and IL-10. Intraperitoneal injection of LM MVs at 80 µg per C57BL/6 mouse did not cause lethal effects or irreversible pathological changes in major organs, indicating that LM MVs were safe. Intraperitoneal immunization of C57BL/6 mice twice with LM MVs mainly induced a high level of LM MV-specific IgG antibodies. In addition, we subcutaneously injected C57BL/6 mice with a mixture of ovalbumin and LM MVs and found that LM MVs exhibited a humoral immune adjuvant effect equal to that of the same amount of alum. The results of this study indicated that LM MVs have good safety and effective immunogenicity and may act as humoral immune adjuvants. Therefore, LM MVs are a potential new choice for antigen and drug delivery vectors.
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Listeria monocytogenes , Animales , Ratones , Ratones Endogámicos C57BL , Citocinas , Factor de Necrosis Tumoral alfa , Inmunoglobulina GRESUMEN
As food-borne pathogens, Bacillus cereus not only produce toxins that contaminate food and threaten human health, but also rely on spores to resist extreme environments. At present, the detection of B. cereus is still at the genome level and it is not easily distinguished from other Bacilli of the same group. Herein, we obtained the aptamers of B. cereus in different phases through Cell-SELEX technology. Then, through step-by-step tailoring and molecular docking, the two best performing aptamers were ascertained and the interaction revealed between the repeated G bases in the aptamer and the polar amino acids in the α-helix of the epiprotein. Based on these aptamers, a multifunctional dumbbell-shaped probe and an ultrasensitive microfluidic chip biosensor were designed. Tests showed that the novel sensor is able to complete detection within 1 h with a limit of detection (LOD) of 9.27 CFU/mL. Moreover, the sensor can be used in complex food environments, such as milk and rice, is able to detect both vegetative cells and spores, and it can also distinguish B. thuringiensis from the same flora. This study can provide a reference for the future development of food-borne pathogenic bacteria aptamer selecting, target interaction analysis, detection methods and equipment.
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Bacillus , Técnicas Biosensibles , Humanos , Bacillus cereus , Microfluídica , Simulación del Acoplamiento Molecular , OligonucleótidosRESUMEN
Oxidative stress plays a key part in cardiovascular event. Growth arrest-specific gene 6 (GAS6) is a vitamin K-dependent ligand which has been shown to exert important effects in heart. The effects of GAS6 were evaluated against hydrogen peroxide (H2O2) induced oxidative stress injury in HL-1 cardiomyocytes. A series of experimental methods were used to analyze the effects of GAS6 on cell viability, apoptosis, oxidative stress, mitochondrial function and AMPK/ACC signaling in H2O2injured HL-1 cells. In this study, we found that H2O2 reduced cell viability, increased apoptotic rate and intracellular reactive oxygen species (ROS). Meanwhile, H2O2 decreased the protein levels of GAS6, and increased the protein level of p-AMPK/AMPK, p-ACC/ACC. Then, we observed that overexpression of GAS6 significantly reduced cell death, manifested as increased cell viability, improved oxidative stress, apoptosis and upregulated the levels of GAS6, p-Axl/Axl, Nrf2, NQO1, HO-1, Bcl-2/Bax, PGC-1α, NRF1, TFAM, p-AMPK/AMPK, and p-ACC/ACC-related protein expression in HL-1 cells and H2O2injured cardiomyocytes. To further verify the results, we successfully constructed GAS6 lentiviral vectors, and found GAS6 shRNA partially reversed the above results. These data suggest that AMPK/ACC may be a downstream effector molecule in the antioxidant action of GAS6. In summary, our findings indicate that activation GAS6/Axl-AMPK signaling protects H2O2induced oxidative stress which is accompanied by the amelioration of oxidative stress, apoptosis, and mitochondrial function.
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Proteínas Quinasas Activadas por AMP , Peróxido de Hidrógeno , Proteínas Quinasas Activadas por AMP/genética , Apoptosis , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo , Transducción de Señal , Tirosina Quinasa del Receptor Axl/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismoRESUMEN
Running wheels for mice residing in the home cage are useful for the continuous measurement of locomotor activity for studies testing exercise interventions or exercise-induced effects on brain and metabolism. Here, we have developed an open source, printable, open-faced running wheel that is automated to collect locomotor information such as distance traveled, wheel direction, and velocity that can be binned into epochs over 24 h or multiple days. This system allows for remote data collection to avoid human interference in mouse behavioral experiments. We tested this system in an activity-based anorexia procedure. Using these wheels, we replicate previous findings that food restriction augments wheel-running activity.
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Anorexia , Actividad Motora , Humanos , Animales , Ratones , EncéfaloRESUMEN
Dapoxetine is used for the treatment of premature ejaculation. The present study developed an HPLC-MS/MS method to determine the levels of dapoxetine in human plasma processed using simple protein precipitation. Dapoxetine-d7 was selected as the internal standard. The established method was performed using a mass spectrometer equipped with an electrospray ionization source in multiple positive ion reactions to monitor the mode using the precursor-to-product ion transitions of m/z 306.2-157.2 and m/z 313.2-164.2 for dapoxetine-d7 and dapoxetine, respectively. The method was evaluated based on its selectivity, linearity, limit of quantification, precision, accuracy, matrix effects, dilution integrity, stability, and extraction recovery. As a result of the model used in the present study, the validated linear ranges of dapoxetine were determined to be 2.00~1000 ng/mL in plasma, and the selectivity, precision, accuracy, dilution integrity, stability, and extraction recovery met the accepted standard. No matrix interference was observed. The method was successfully validated and applied to pharmacokinetic studies in healthy Chinese volunteers during the fasting and postprandial periods, respectively.
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Bencilaminas , Espectrometría de Masas en Tándem , Cromatografía Líquida de Alta Presión/métodos , Humanos , Masculino , Naftalenos , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos , Equivalencia TerapéuticaRESUMEN
Triple-negative breast cancer is the most aggressive type of breast cancer, with a poor prognosis, while effective treatment options are limited. In this study, the anti-tumor effect of lupeol, a natural triterpenoid, toward breast cancer cells and the underlying mechanisms were examined. We firstly predict the primary pathways of lupeol inhibited to TNBC by a network pharmacology approach, which indicated that lupeol may inhibit TNBC via multiple signaling pathways. In addition, experimental data showed that lupeol exhibited outstanding anti-proliferative and anti-metastatic abilities in vitro and in vivo. Additional intrinsic mechanism studies revealed that lupeol might induce autophagy by inhibiting the Akt-mTOR pathway, and activating an autophagy inhibited epithelial-mesenchymal transition (EMT). This study demonstrated that lupeol could inhibit TNBC cells by inducing autophagy, suggesting lupeol as a potential treatment alternative or as a dietary supplement for TNBC, as well as offering novel insights into the anti-cancer effect of lupeol.
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Transición Epitelial-Mesenquimal , Neoplasias de la Mama Triple Negativas , Autofagia , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Humanos , Triterpenos Pentacíclicos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismoRESUMEN
OBJECTIVE: To establish a method for extracting Listeria monocytogenesmembrane vesicles (LM-MVs) and to analyze the characteristics of LM-MVs and their ability to induce innate immune effect in vitro so as to lay the foundation for research into using LM-MVs as vaccine carrier and drug delivery platform. METHODS: The membrane vesicles secreted by Listeria monocytogenes were extracted through a continuous process, including culturing, centrifugation, filtration, ultrafiltration concentration and ultracentrifugation. The morphological characteristics of LM-MVs were observed with transmission electron microscope, and particle size distribution were measured by dynamic light scattering analysis. SDS-PAGE and Western blot were used to analyze the protein composition of LM-MVs. CCK-8 cell proliferation and toxicity determination experiments were done to analyze their effect on the proliferation of innate immune cells, and qPCR was used to analyze their ability to induce innate immune responses. RESULTS: A method for extracting LM-MVs was successfully established. Under the transmission electron microscope, LM-MVs presented a nearly circular film-like structure, and dynamic light scattering analysis showed that their sizes were between 65 and 190 nm. SDS-PAGE and Western blot showed that LM-MVs contained proteins, including listeriolysin O (LLO). CCK-8 cell proliferation and toxicity experiment showed that after intervention with 10, 20 and 50 µg/mL of LM-MVs for 24 hours, the proliferation rate of DC 2.4 mouse dendritic cell line was higher than that of non-interventional DC 2.4 cells ( P<0.05); after intervention with 0.1, 1, 10, 20 and 50 µg/mL of LM-MVs for 24 hours, the proliferation rate of RAW 264.7 cells was higher than that of non-interventional RAW 264.7 cells ( P<0.01). The results of qPCR showed that, after intervention with 50 µg/mL of LM-MVs, the expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 and IL-10 in RAW 264.7 cells were higher than those of non-intervention control cells ( P<0.05). CONCLUSIONS: The method established in the study can be used to extract LM-MVs. The extracted LM-MVs have a diameter of 65-190 nm and a nearly circular membrane-like structure. They can secrete a variety of protein components and stimulate innate immune responses.
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Listeria monocytogenes , Animales , Línea Celular , Células Dendríticas , Ratones , Células RAW 264.7RESUMEN
Plant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO42-) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana, AtSULTR4;1, in complex with SO42- at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO42- is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO42- are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO42- transport. Glu347, which is ~7 Å from the bound SO42-, is required for H+-driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO42- transport, suggesting a regulatory function of the STAS domain.
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Proteínas de Transporte de Anión/química , Proteínas de Transporte de Anión/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transportadores de Sulfato/química , Transportadores de Sulfato/metabolismo , Proteínas de Transporte de Anión/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sitios de Unión/genética , Microscopía por Crioelectrón , Ácido Glutámico/química , Modelos Moleculares , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Electricidad Estática , Transportadores de Sulfato/genética , Sulfatos/metabolismoRESUMEN
Traditional cancer therapeutics have been criticized due to various adverse effects and insufficient damage to targeted tumors. The breakthrough of nanoparticles provides a novel approach for upgrading traditional treatments and diagnosis. Actually, nanoparticles can not only solve the shortcomings of traditional cancer diagnosis and treatment, but also create brand-new perspectives and cutting-edge devices for tumor diagnosis and treatment. However, most of the research about nanoparticles stays in vivo and in vitro stage, and only few clinical researches about nanoparticles have been reported. In this review, we first summarize the current applications of nanoparticles in cancer diagnosis and treatment. After that, we propose the challenges that hinder the clinical applications of NPs and provide feasible solutions in combination with the updated literature in the last two years. At the end, we will provide our opinions on the future developments of NPs in tumor diagnosis and treatment.
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A novel bifunctional oligonucleotide (OND) probe with single fluorescent group HEX labelled at 5'-end was designed for detecting trace Ag(I) and Pb(II) in real samples. In the presence of Ag(I), the hairpin structure originating from Ag(I) induced cytosine-Ag(I)-cytosine mismatches causes the proximity of the HEX to the consecutive guanine bases (G)4 at 3'-terminal, resulting in the fluorescence quenching of the HEX. While in the presence of Pb(II), the G-quadruplex structure originating from two G-quartet planes by the intramolecular hydrogen bond with Pb(II) also causes the HEX approaching the (G)4 terminal and consequently the fluorescence quenching. The results showed the quantitative detection of trace Ag(I) and Pb(II) both in the linear response ranges of 1.0-20.0 × 10-9 mol L-1 with no visible interferences of other 11 metal ions observed. And the detection limits were 82 × 10-12 mol L-1 for Ag(I), 92 × 10-12 mol L-1 for Pb(II), respectively. The fluorescence quenching mechanism of the (G)4 to HEX was verified to be the photoinduced electron transfer in the aspect of thermodynamics. This method provided a feasible application for sensitive and selective detection of Pb(II) and Ag(I) in water and Chinese traditional herbs with convenient operation.