82 research outputs found

    A proteomic approach to analyzing responses of Arabidopsis thaliana root cells to different gravitational conditions using an agravitropic mutant, pin2 and its wild type

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    <p>Abstract</p> <p>Background</p> <p>Root gravitropsim has been proposed to require the coordinated, redistribution of the plant signaling molecule auxin within the root meristem, but the underlying molecular mechanisms are still unknown. PIN proteins are membrane transporters that mediate the efflux of auxin from cells. The PIN2 is important for the basipetal transport of auxin in roots and plays a critical role in the transmission of gravity signals perceived in the root cap to the root elongation zone. The loss of function <it>pin2 </it>mutant exhibits a gravity-insensitive root growth phenotype. By comparing the proteomes of wild type and the <it>pin2 </it>mutant root tips under different gravitational conditions, we hope to identify proteins involved in the gravity-related signal transduction.</p> <p>Results</p> <p>To identify novel proteins involved in the gravity signal transduction pathway we have carried out a comparative proteomic analysis of Arabidopsis <it>pin2 </it>mutant and wild type (WT) roots subjected to different gravitational conditions. These conditions included horizontal (H) and vertical (V) clinorotation, hypergravity (G) and the stationary control (S). Analysis of silver-stained two-dimensional SDS-PAGE gels revealed 28 protein spots that showed significant expression changes in altered gravity (H or G) compared to control roots (V and S). Whereas the majority of these proteins exhibited similar expression patterns in WT and <it>pin2 </it>roots, a significant number displayed different patterns of response between WT and <it>pin2 </it>roots. The latter group included 11 protein spots in the H samples and two protein spots in the G samples that exhibited an altered expression exclusively in WT but not in <it>pin2 </it>roots. One of these proteins was identified as annexin2, which was induced in the root cap columella cells under altered gravitational conditions.</p> <p>Conclusions</p> <p>The most interesting observation in this study is that distinctly different patterns of protein expression were found in WT and <it>pin</it>2 mutant roots subjected to altered gravity conditions. The data also demonstrate that PIN2 mutation not only affects the basipetal transport of auxin to the elongation zone, but also results in an altered expression of proteins in the root columella.</p

    Understanding the Passivation Mechanisms and Opto-Electronic Spectral Response in Methylammonium Lead Halide Perovskite Single Crystals

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    Attaining control over the surface traps in halide perovskites is critical for the tunability of ultimate device characteristics. Here, we present a study on the modulation of photophysical properties, surface traps, and recombination in MAPbI(3) single crystals (MSCs) with methylamine (MA) vapor surface treatment. Transient photoluminescence spectroscopy in conjunction with density functional theory calculations reveals that nonradiative recombination related to Pb2+ becomes mitigated after MA vaporing while radiative recombination via bimolecular path tends to increase, which originates from the passivation of Pb ions with the Lewis base nitrogen in MA. In contrast to the broad photoresponse in the pristine MSC photodiodes, application of MA surface treatments leads to a spectral narrowing effect (SNE) in MSCs with the response peak width</p

    Nanoparticle-based drug delivery systems to enhance cancer immunotherapy in solid tumors

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    Immunotherapy has developed rapidly in solid tumors, especially in the areas of blocking inhibitory immune checkpoints and adoptive T-cell transfer for immune regulation. Many patients benefit from immunotherapy. However, the response rate of immunotherapy in the overall population are relatively low, which depends on the characteristics of the tumor and individualized patient differences. Moreover, the occurrence of drug resistance and adverse reactions largely limit the development of immunotherapy. Recently, the emergence of nanodrug delivery systems (NDDS) seems to improve the efficacy of immunotherapy by encapsulating drug carriers in nanoparticles to precisely reach the tumor site with high stability and biocompatibility, prolonging the drug cycle of action and greatly reducing the occurrence of toxic side effects. In this paper, we mainly review the advantages of NDDS and the mechanisms that enhance conventional immunotherapy in solid tumors, and summarize the recent advances in NDDS-based therapeutic strategies, which will provide valuable ideas for the development of novel tumor immunotherapy regimen

    Resistance Switching Behavior in Rectangle-Nano-Pattern SrTiO3 Induced by Simple Annealing.

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    The tunability of semi-conductivity in SrTiO3 single crystal substrates has been realized by a simple encapsulated annealing method under argon atmosphere. This high temperature annealing-induced property changes are characterized by the transmission spectra, scanning electron microscopy (SEM) and synchrotron-based X-ray absorption (XAS). We find the optical property is strongly influenced by the annealing time (with significant decrease of transmittance). A sub gap absorption at ~427 nm is detected which is attributed to the introduction of oxygen vacancy. Interestingly, in the SEM images, annealing-induced regularly rectangle nano-patterns are directly observed which is contributed to the conducting filaments. The XAS of O K-edge spectra shows the changes of electronic structure by annealing. Very importantly, resistance switching response is displayed in the annealed SrTiO3 single crystal. This suggests a possible simplified route to tune the conductivity of SrTiO3 and further develop novel resistance switching materials

    Patterns of adverse childhood experiences and suicidal behaviors in adolescents: A four-province study in China

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    This is an accepted manuscript of a paper published by Elsevier on 23/02/2021, available online at: https://doi.org/10.1016/j.jad.2021.02.045 The accepted manuscript of the publication may differ from the final published version.Background:: Adverse childhood experiences (ACEs) are associated with increased suicidal behaviors in adolescents and most research has been restricted to certain types of or cumulative exposure to ACEs. Few studies have examined the association between patterns of ACEs and suicidal behaviors. Objective:: To identify the contributions of type and pattern of exposure to ACEs to suicidal behaviors and their gender differences among middle school students in China. Methods:: A school-based health survey was conducted in four provinces in China between 2017 and 2018. 14 500 students aged 10–20 years completed standard questionnaires, to record details of ACEs, suicide ideation, suicide plan, and suicide attempt. Results:: Latent class analysis indicated four distinct patterns of ACEs exposure: high ACEs (6.3%), high abuse and neglect (21.4%), high neglect (45.5%), and low ACEs (26.8%). Logistic analyses showed that, compared with low ACEs, the high ACEs were more likely to report suicidal behaviors. No gender differences were found in the independent effects of ACEs type or pattern on suicidal behaviors, except for the emotional neglect associated with suicidal behaviors in girls than boys. Limitations:: The study was cross-sectional and used self-reported questionnaires. Thus, it is difficult to establish a causal relationship between patterns of ACEs and suicidal behaviors. Conclusion:: Our findings addressed the need for a comprehensive consideration of ACEs in preventive healthcare work to identify children exposed to the most problematic ACE patterns. The study provided the evidence of targeted intervention to preempt the emergence of suicide behavior in at-risk students in adolescents.Funding for the project was provided by National Natural Science Foundation of China (82073576 & 81773453).Published versio

    A Role for MK2 in Enhancing Neutrophil-Derived ROS Production and Aggravating Liver Ischemia/Reperfusion Injury

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    Increased inflammatory responses and enhanced reactive oxygen species contribute to hepatic ischemia/reperfusion (I/R) injury, however the modulatory mechanisms haven't been completely unveiled. Here, we report that genetic deficiency of MAPK-activated protein kinase 2 (MK2) protected against hepatic I/R injury and decreased hepatic neutrophil accumulation in MK2−/− mice. Depletion of neutrophil attenuated hepatic I/R injury in wide type mice. In response to C5a stimulation, MK2−/− neutrophils generated less superoxide in which both NADPH oxidase activation and p47phox phosphorylation were decreased. Furthermore, Ser329 of p47phox was identified for enhancement of superoxide production. The Ser329 phosphorylation was reduced in MK2−/− neutrophils. To determine whether MK2 modulates hepatic I/R injury via activating neutrophils, we generated myeloid-specific MK2 deletion mice (MK2Lyz2−KO) and liver I/R injury was reduced in MK2Lyz2−KO mice. Our results indicate that MK2 augments hepatic I/R injury and induces ROS production with increased p47phox phosphorylation and MK2 is a potential drug target for treating hepatic I/R injury

    Enhanced Photoelectrochemical Detection of Bioaffinity Reactions by Vertically Oriented Au Nanobranches Complexed with a Biotinylated Polythiophene Derivative

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    Four nanostructured Au electrodes were prepared by a simple and templateless electrochemical deposition technique. After complexing with a biotinylated polythiophene derivative (PTBL), photocurrent generation and performance of PTBL/Au-nanostructured electrodes as photoelectrochemical biosensors were investigated. Among these four nanostructured Au electrodes, vertically oriented nanobranches on the electrode significantly improved the photoelectric conversion, because the vertically oriented nanostructures not only benefit light harvesting but also the transfer of the photogenerated charge carriers. Owing to this advantaged nanostructure, the PTBL/Au-nanobranch electrode showed higher sensitivity and faster response times in the photoelectrochemical detection of a streptavidin-biotin affinity reaction compared to a PTBL/Au-nanoparticle electrode

    Association between abnormal plasma metabolism and brain atrophy in alcohol-dependent patients

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    ObjectiveIn this study, we aimed to characterize the plasma metabolic profiles of brain atrophy and alcohol dependence (s) and to identify the underlying pathogenesis of brain atrophy related to alcohol dependence.MethodsWe acquired the plasma samples of alcohol-dependent patients and performed non-targeted metabolomic profiling analysis to identify alterations of key metabolites in the plasma of BA-ADPs. Machine learning algorithms and bioinformatic analysis were also used to identify predictive biomarkers and investigate their possible roles in brain atrophy related to alcohol dependence.ResultsA total of 26 plasma metabolites were significantly altered in the BA-ADPs group when compared with a group featuring alcohol-dependent patients without brain atrophy (NBA-ADPs). Nine of these differential metabolites were further identified as potential biomarkers for BA-ADPs. Receiver operating characteristic curves demonstrated that these potential biomarkers exhibited good sensitivity and specificity for distinguishing BA-ADPs from NBA-ADPs. Moreover, metabolic pathway analysis suggested that glycerophospholipid metabolism may be highly involved in the pathogenesis of alcohol-induced brain atrophy.ConclusionThis plasma metabolomic study provides a valuable resource for enhancing our understanding of alcohol-induced brain atrophy and offers potential targets for therapeutic intervention

    The FOXK1-CCDC43 Axis Promotes the Invasion and Metastasis of Colorectal Cancer Cells

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    Background/Aims: The CCDC43 gene is conserved in human, rhesus monkey, mouse and zebrafish. Bioinformatics studies have demonstrated the abnormal expression of CCDC43 gene in colorectal cancer (CRC). However, the role and molecular mechanism of CCDC43 in CRC remain unknown. Methods: The functional role of CCDC43 and FOXK1 in epithelial-mesenchymal transition (EMT) was determined using immunohistochemistry, flow cytometry, western blot, EdU incorporation, luciferase, chromatin Immunoprecipitation (ChIP) and cell invasion assays. Results: The CCDC43 gene was overexpressed in human CRC. High expression of CCDC43 protein was associated with tumor progression and poor prognosis in patients with CRC. Moreover, the induction of EMT by CCDC43 occurred through TGF-β signaling. Furthermore, a positive correlation between the expression patterns of CCDC43 and FOXK1 was observed in CRC cells. Promoter assays demonstrated that FOXK1 directly bound and activated the human CCDC43 gene promoter. In addition, CCDC43 was necessary for FOXK1- mediated EMT and metastasis in vitro and vivo. Taken together, this work identified that CCDC43 promoted EMT and was a direct transcriptional target of FOXK1 in CRC cells. Conclusion: FOXK1-CCDC43 axis might be helpful to develop the drugs for the treatment of CRC
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