53 research outputs found

    Arabidopsis blue light receptor phototropin 1 undergoes blue light-induced activation in membrane microdomains

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    Phototropin (phot)-mediated signaling initiated by blue light (BL) plays a critical role in optimizing photosynthetic light capture at the plasma membrane (PM) in plants. However, the mechanisms underlying the regulation of phot activity at the PM in response to BL remain largely unclear. In this study, by single-particle tracking and step-wise photobleaching analysis we demonstrated that in the dark phot1-GFP proteins remain in an inactive state and mostly present as a monomer. The phot1-GFP diffusion rate and its dimerization increased in a dose-dependent manner in response to BL. In contrast, BL did not affect the lateral diffusion of kinase-inactive phot1 -GFP, whereas it did enhance its dimerization, suggesting that phot1 dimerization is independent of its phosphorylation. Förster resonance energy transfer-fluorescence lifetime imaging microscopy (FRET-FLIM) analysis revealed that the interaction between phot1-GFP and AtRem1.3-mCherry was enhanced along with increased time of BL treatment. However, the BL-dependent interaction was not obvious in plants co-expressing phot1 -GFP and AtRem1.3-mCherry, implicating that BL facilitated the translocation of functional phot1-GFP into AtRem1.3-labeled microdomains to activate phot-mediated signaling. Conversely, sterol depletion attenuated phot1-GFP dynamics, dimerization, and phosphorylation. Taken together, these results indicate that membrane microdomains act as an organizing platform essential for proper function of activated phot1 at the PM

    Impact of Chemotherapy Regimens on Normal Tissue Complication Probability Models of Acute Hematologic Toxicity in Rectal Cancer Patients Receiving Intensity Modulated Radiation Therapy With Concurrent Chemotherapy From a Prospective Phase III Clinical Trial

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    Purpose: To determine whether there are differences in bone marrow tolerance to chemoradiotherapy (CRT) between two chemotherapy regimens according to FOWARC protocol and how chemotherapy regimens affect radiation dose parameters and normal tissue complication probability (NTCP) modelings that correlate with acute hematologic toxicity (HT) in rectal cancer patients treated with intensity modulated radiation therapy (IMRT) and concurrent chemotherapy.Materials and Methods: One hundred and twenty-eight rectal cancer patients who received IMRT from a single institution were recruited from Chinese FOWARC multicenter, open-label, randomized phase III trial. We assessed HT in these patients who were separated into two groups: Oxaliplatin (L-OHP) + 5- fluorouracil (5FU) (FOLFOX, 70 of 128) and 5FU (58 of 128). The pelvic bone marrow (PBM) was divided into three subsites: lumbosacral spine (LSS), ilium (I), and lower pelvic (LP). The endpoint for HT was grade ≥3 (HT3+) and grade ≥2 (HT2+) leukopenia, neutropenia, anemia and thrombocytopenia. Logistic regression was used to analyze the association between HT2+/HT3+ and dosimetric parameters. Lyman-Kutcher-Burman (LKB) model was used to calculate NTCP.Results: Sixty-eight patients experienced HT2+: 22 of 58 (37.9%) 5FU and 46 of 70 (65.7%) FOLFOX (p = 0.008), while twenty-six patients experienced HT3+: 4 of 58 (6.9%) 5FU and 22 of 70 (31.4%) FOLFOX (p = 0.016). PBM and LP dosimetric parameters were correlated with HT2+ in the 5FU group but not in the FOLFOX group. No PBM dosimetric parameters were correlated with HT3+ in both groups. For PBM, NTCP at HT3+ was 0.32 in FOLFOX group relative to 0.10 in 5FU subset (p < 0.05).Conclusion: Patients receiving FOLFOX have lower BM tolerance to CRT than those receiving 5FU. Low-dose radiation to the PBM is predictive for HT2+ in patients who received 5FU. NTCP modeling in FOLFOX group predicts much higher risk of HT3+ than 5FU group

    Evidence for an oncogenic role of HOXC6 in human non-small cell lung cancer

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    Background Identification of specific biomarkers is important for the diagnosis and treatment of non-small cell lung cancer (NSCLC). HOXC6 is a homeodomain-containing transcription factor that is highly expressed in several human cancers; however, its role in NSCLC remains unknown. Methods The expression and protein levels of HOXC6 were assessed in NSCLC tissue samples by Quantitative real-time PCR (qRT-PCR) and immunohistochemistry, respectively. HOXC6 was transfected into the NSCLC cell lines A549 and PC9, and used to investigate its effect on proliferation, migration, and invasion using CFSE, wound healing, and Matrigel invasion assays. Next-generation sequencing was also used to identify downstream targets of HOXC6 and to gain insights into the molecular mechanisms underlying its biological function. Results HOXC6 expression was significantly increased in 66.6% (20/30) of NSCLC tumor samples in comparison to normal controls. HOXC6 promoted proliferation, migration, and invasion of NSCLC cells in vitro. RNA-seq analysis demonstrated the upregulation of 310 and 112 genes in A549-HOXC6 and PC9-HOXC6 cells, respectively, and the downregulation of 665 and 385 genes in A549-HOXC6 and PC9-HOXC6 cells, respectively. HOXC6 was also found to regulate the expression of genes such as CEACAM6, SPARC, WNT6, CST1, MMP2, and KRT13, which have documented pro-tumorigenic functions. Discussion HOXC6 is highly expressed in NSCLC, and it may enhance lung cancer progression by regulating the expression of pro-tumorigenic genes involved in proliferation, migration, and invasion. Our study highlighted the oncogenic potential of HOXC6, and suggests that it may be a novel biomarker for the diagnosis and treatment of NSCLC

    HOXC6 promotes migration, invasion and proliferation of esophageal squamous cell carcinoma cells via modulating expression of genes involved in malignant phenotypes

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    Background HOXC6 is a member of the HOX gene family. The elevated expression of this gene occurs in prostate and breast cancers. However, the role of HOXC6 in esophageal squamous cell carcinoma (ESCC) remains largely uninvestigated. Methods The expression of HOXC6 was examined by immunohistochemistry, quantitative real-time PCR and immunoblotting assays. The lentivirus-mediated expression of HOXC6 was verified at mRNA and protein levels. Wound healing and Matrigel assays were performed to assess the effect of HOXC6 on the migration and invasion of cancer cells. The growth curving, CCK8, and colony formation assays were utilized to access the proliferation capacities. RNA-seq was performed to evaluate the downstream targets of HOXC6. Bioinformatic tool was used to analyze the gene expression. Results HOXC6 was highly expressed in ESCC tissues. HOXC6 overexpression promoted the migration, invasion, and proliferation of both Eca109 and TE10 cells. There were 2,155 up-regulated and 759 down-regulated genes in Eca109-HOXC6 cells and 95 up-regulated and 47 down-regulated genes in TE10-HOXC6 cells compared with the results of control. Interestingly, there were only 20 common genes, including 17 up-regulated and three down-regulated genes with similar changes upon HOXC6 transfection in both cell lines. HOXC6 activated several crucial genes implicated in the malignant phenotype of cancer cells. Discussion HOXC6 is highly expressed in ESCC and promotes malignant phenotype of ESCC cells. HOXC6 can be used as a new therapeutic target of ESCC

    Highly hydrophobic and adhesive performance of graphene films

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    Graphene films with high hydrophobic and adhesive performance were fabricated via two simple steps: chemical exfoliation of natural flake graphite following redox, and film formation by suction filtration without any chemical modification. Irregularly stacked multilayer graphene nanosheets comprised the microstructure, whereas folding and agglomeration of graphene nanoflakes with few layers comprised the nanostructure. The films also showed remarkable surface wettability and reversible transition from hydrophobicity to hydrophilicity via periodic alternation of ultraviolet irradiation and air storage. Based on Wenzel\u27s theory and adsorption dynamics, an optimum mechanism is proposed for the surface wettability behavior. On the one hand, the film microstructure and nanostructure enhance the graphene surface hydrophobicity. On the other hand, the capillary force is maximized by the nanostructure such that water fills the grooves of the rough solid surface. This result is a strong interaction between water and the film surface giving highly adhesive property to the films. The highly hydrophobic and adhesive performance of the graphene films could be useful in the device and biomaterials application

    Comprehensive Genomic Survey, Structural Classification, and Expression Analysis of WRKY Transcription Factor  Family in Rhododendron simsii

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    (1) Rhododendron is one of the top ten traditional flowers in China, with both high ornamental and economic values. However, with the change of the environment, Rhododendron suffers from various biological stresses. The WRKY transcription factor is a member of the most crucial transcription factor families, which plays an essential regulatory role in a variety of physiological processes and developmental stresses. (2) In this study, 57 RsWRKYs were identified using genome data and found to be randomly distributed on 13 chromosomes. Based on gene structure and phylogenetic relationships, 57 proteins were divided into three groups: I, II, and III. Multiple alignments of RsWRKYs with Arabidopsis thaliana homologous genes revealed that WRKY domains in different groups had different conserved sites. RsWRKYs have a highly conserved domain, WRKYGQK, with three variants, WRKYGKK, WRKYGEK, and WRKYGRK. Furthermore, cis-acting elements analysis revealed that all of the RsWRKYs had stress and plant hormone cis-elements, with figures varying by group. Finally, the expression patterns of nine WRKY genes treated with gibberellin acid (GA), methyl jasmonate (MeJA), heat, and drought in Rhododendron were also measured using quantitative real-time PCR (qRT-PCR). The results showed that the expression levels of the majority of RsWRKY genes changed in response to multiple phytohormones and abiotic stressors. (3) This current study establishes a theoretical basis for future studies on the response of RsWRKY transcription factors to various hormone and abiotic stresses as well as a significant foundation for the breeding of new stress-tolerant Rhododendron varieties

    MBES Seabed Sediment Classification Based on a Decision Fusion Method Using Deep Learning Model

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    High-precision habitat mapping can contribute to the identification and quantification of the human footprint on the seafloor. As a representative of seafloor habitats, seabed sediment classification is crucial for marine geological research, marine environment monitoring, marine engineering construction, and seabed biotic and abiotic resource assessment. Multibeam echo-sounding systems (MBES) have become the most popular tool in terms of acoustic equipment for seabed sediment classification. However, sonar images tend to consist of obvious noise and stripe interference. Furthermore, the low efficiency and high cost of seafloor field sampling leads to limited field samples. The factors above restrict high accuracy classification by a single classifier. To further investigate the classification techniques for seabed sediments, we developed a decision fusion algorithm based on voting strategies and fuzzy membership rules to integrate the merits of deep learning and shallow learning methods. First, in order to overcome the influence of obvious noise and the lack of training samples, we employed an effective deep learning framework, namely random patches network (RPNet), for classification. Then, to alleviate the over-smoothness and misclassifications of RPNet, the misclassified pixels with a lower fuzzy membership degree were rectified by other shallow learning classifiers, using the proposed decision fusion algorithm. The effectiveness of the proposed method was tested in two areas of Europe. The results show that RPNet outperforms other traditional classification methods, and the decision fusion framework further improves the accuracy compared with the results of a single classifier. Our experiments predict a promising prospect for efficiently mapping seafloor habitats through deep learning and multi-classifier combinations, even with few field samples

    Differences in phytoaccumulation of organic pollutants in freshwater submerged and emergent plants

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    Plants play an important role as sinks for or indicators of semivolatile organic pollutants, however most studies have focused on terrestrial plants and insufficient information has been obtained on aquatic plants to clarify the accumulation of organic pollutants via air-to-leaf vs. water-to-leaf pathways. The presence of p, p&#39;-dichlorodiphenyldichloroethylene (p, p&#39;-DDE), hexachlorobenzene (HCB), 15 polycyclic aromatic hydrocarbons (PAHs), and 9 substituted PAHs (s-PAHs), including oxy-PAHs and sulfur-PAHs, in 10 submerged and emergent plants collected from Lake Dianchi was analyzed in this study. Relatively low concentrations of p, p&#39;-DDE (ND to 2.22 ngig wet weight [ww]) and HCB (0.24-0.84 ng/g ww) and high levels of PAHs (46-244 ng/g ww) and s-PAHs (6.0-46.8 ng/g ww) were observed in the aquatic plants. Significantly higher concentrations of most of the compounds were detected in the leaves of the submerged plants than in those of the emergent plants. The percentages of concentration difference relative to the concentrations in the submerged plants were estimated at 55%, 40%, 10%-69% and 0.5% 79% for p, p&#39;-DDE, HCB, PAHs, and s-PAHs, respectively. The percentages were found to increase significantly with an increase in log Kow, suggesting that the high level of phytoaccumulation of pollutants in aquatic plants is due to hydrophobicity-dependent diffusion via the water-to-leaf pathway and the mesophyll morphology of submerged plants. (C) 2018 Elsevier Ltd. All rights reserved.</p

    Physiological and transcriptomic analysis of yellow leaf coloration in Populus deltoides Marsh.

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    Populus deltoides Marsh has high ornamental value because its leaves remain yellow during the non-dormant period. However, little is known about the regulatory mechanism of leaf coloration in P. deltoides Marsh. Thus, we analyzed the physiological and transcriptional differences of yellow leaves (mutant) and green leaves (wild-type) of P. deltoides Marsh. Physiological experiments showed that the contents of chlorophyll (Chl) and carotenoid were lower in mutant leaves, and the flavonoid content did not differ significantly between mutant and wild-type leaves. Transcriptomic sequencing was further used to identify 153 differentially expressed genes (DEGs). Functional classifications based on Gene Ontology enrichment and Genome enrichment analysis indicated that the DEGs were involved in Chl biosynthesis and flavonoid biosynthesis pathways. Among these, geranylgeranyl diphosphate (CHLP) genes associated with Chl biosynthesis showed down-regulation, while chlorophyllase (CLH) genes associated with Chl degradation were up-regulated in yellow leaves. The expression levels of these genes were further confirmed using quantitative real-time PCR (RT-qPCR). Furthermore, the estimation of the main precursors of Chl confirmed that CHLP is a vital enzyme for the yellow leaf color phenotype. Consequently, the formation of yellow leaf color is due to the disruption of Chl synthesis or catabolism rather than flavonoid synthesis. These results contribute to our understanding of mechanisms and regulation of leaf color variation in poplar at the transcriptional level
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