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1.
Cancer Immunol Immunother ; 73(5): 84, 2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38554155

ABSTRACT

This study aims to investigate the diagnostic potential of IL-2 for PDAC and develop a method to improve the dendritic cell (DC) based vaccine against PDAC. The gene expression data and clinical characteristics information for 178 patients with PDAC were obtained from The Cancer Genome Atlas (TCGA). DCs were isolated from Human peripheral blood mononuclear cells (PBMCs) and were cultured in 4 different conditions. DCs were pulsed by tumor cell lysates or KRAS G12D1 - 23 peptide, and then used to activate T cells. The mixture of DCs and T cells were administered to xenograft mouse model through the tail vein. The infiltration of DCs and T cells were detected by immunohistochemistry. The generation of KRAS G12D mutation specific cytotoxic T cells was determined by in vitro killing assay. We observed that PDAC patients with higher IL-2 mRNA levels exhibited improved overall survival and increased infiltration of CD8 + T cells, NK cells, naïve B cells, and resting myeloid DCs in the tumor microenvironment. IL-2 alone did not enhance DC proliferation, antigen uptake, or apoptosis inhibition unless co-cultured with PBMCs. DCs co-cultured with PBMCs in IL-2-containing medium demonstrated the strongest tumor repression effect in vitro and in vivo. Compared to DCs obtained through the traditional method (cultured in medium containing GM-CSF and IL-4), DCs cultured with PBMCs, and IL-2 exhibited increased tumor infiltration capacity, potentially facilitating sustained T cell immunity. DCs cultured in the PBMCs-IL-2 condition could promote the generation of cytotoxic T cells targeting tumor cells carrying KRAS G12D mutation.


Subject(s)
Interleukin-2 , Pancreatic Neoplasms , Humans , Animals , Mice , Interleukin-2/metabolism , Dendritic Cells , Leukocytes, Mononuclear , Proto-Oncogene Proteins p21(ras)/genetics , T-Lymphocytes, Cytotoxic , Pancreatic Neoplasms/metabolism , Tumor Microenvironment
2.
BMC Plant Biol ; 23(1): 23, 2023 Jan 12.
Article in English | MEDLINE | ID: mdl-36631736

ABSTRACT

BACKGROUND: Protein lysine 2-hydroxyisobutyrylation (Khib) is a novel post-translational modification (PTM) discovered in cells or tissues of animals, microorganisms and plants in recent years. Proteome-wide identification of Khib-modified proteins has been performed in several plant species, suggesting that Khib-modified proteins are involved in a variety of biological processes and metabolic pathways. However, the protein Khib modification in soybean, a globally important legume crop that provides the rich source of plant protein and oil, remains unclear. RESULTS: In this study, the Khib-modified proteins in soybean leaves were identified for the first time using affinity enrichment and high-resolution mass spectrometry-based proteomic techniques, and a systematic bioinformatics analysis of these Khib-modified proteins was performed. Our results showed that a total of 4251 Khib sites in 1532 proteins were identified as overlapping in three replicates (the raw mass spectrometry data are available via ProteomeXchange with the identifier of PXD03650). These Khib-modified proteins are involved in a wide range of cellular processes, particularly enriched in biosynthesis, central carbon metabolism and photosynthesis, and are widely distributed in subcellular locations, mainly in chloroplasts, cytoplasm and nucleus. In addition, a total of 12 sequence motifs were extracted from all identified Khib peptides, and a basic amino acid residue (K), an acidic amino acid residue (E) and three aliphatic amino acid residues with small side chains (G/A/V) were found to be more preferred around the Khib site. Furthermore, 16 highly-connected clusters of Khib proteins were retrieved from the global PPI network, which suggest that Khib modifications tend to occur in proteins associated with specific functional clusters. CONCLUSIONS: These findings suggest that Khib modification is an abundant and conserved PTM in soybean and that this modification may play an important role in regulating physiological processes in soybean leaves. The Khib proteomic data obtained in this study will help to further elucidate the regulatory mechanisms of Khib modification in soybean in the future.


Subject(s)
Haemophilus influenzae type b , Lysine , Animals , Lysine/metabolism , Glycine max/genetics , Glycine max/metabolism , Haemophilus influenzae type b/metabolism , Proteomics/methods , Proteome/metabolism , Protein Processing, Post-Translational
3.
Opt Express ; 31(14): 23040-23055, 2023 Jul 03.
Article in English | MEDLINE | ID: mdl-37475398

ABSTRACT

Metal cylindrical shaft parts are critical components in industrial manufacturing that require high standards for roundness error and surface roughness. When using the self-developed multi-beam angle sensor (MBAS) to detect metal cylindrical shaft parts, the distorted multi-spots degrade the measurement accuracy due to the nonlinear distortion caused by the metal material's reflective properties and surface roughness. In this study, we propose a spot coordinate prediction network (SCPNet), which is a deep-learning neural network designed to predict spot coordinates, in combination with Hough circle detection for localization. The singular value decomposition (SVD) model is employed to eliminate the tilt error to achieve high-precision, three-dimensional (3D) surface reconstruction of metal cylindrical shaft parts. The experimental results demonstrate that SCPNet can effectively correct distorted multi-spots, with an average error of the spot center of 0.0612 pixels for ten points. The proposed method was employed to measure metal cylindrical shaft parts with radii of 10 mm, 20 mm, 35 mm, and 50 mm, with resulting standard deviation (STD) values of 0.0022 µm, 0.0026 µm, 0.0028 µm, and 0.0036 µm, respectively.

4.
Food Microbiol ; 99: 103821, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34119106

ABSTRACT

Shiga toxin-producing E. coli (STEC) are major foodborne pathogens. While many studies have focused on the "top-7 STEC", little is known for minor serogroups. A total of 284 non-top-7 STEC strains isolated from cattle feces were subjected to whole-genome sequencing (WGS) to determine the serotypes, the presence of virulence genes and antimicrobial resistance (AMR) determinants. Nineteen typeable and three non-typeable serotypes with novel O-antigen loci were identified. Twenty-one AMR genes and point mutations in another six genes that conferred resistance to 10 antimicrobial classes were detected, as well as 46 virulence genes. The distribution of 33 virulence genes and 15 AMR determinants exhibited significant differences among serotypes (p < 0.05). Among all strains, 81.7% (n = 232) and 14.1% (n = 40) carried stx2 and stx1 only, respectively; only 4.2% (n = 12) carried both. Subtypes stx1a, stx1c, stx2a, stx2c, stx2d, and stx2g were identified. Forty-six strains carried eae and stx2a and therefore had the potential cause severe diseases; 47 strains were genetically related to human clinical strains inferred from a pan-genome phylogenetic tree. We were able to demonstrate the utility of WGS as a surveillance tool to characterize the novel serotypes, as well as AMR and virulence profiles of uncommon STEC that could potentially cause human illness.


Subject(s)
Cattle Diseases/microbiology , Drug Resistance, Bacterial , Escherichia coli Infections/veterinary , Shiga-Toxigenic Escherichia coli/isolation & purification , Animals , Anti-Bacterial Agents/pharmacology , Cattle , Escherichia coli Infections/microbiology , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Feces/microbiology , Phylogeny , Serogroup , Shiga-Toxigenic Escherichia coli/drug effects , Shiga-Toxigenic Escherichia coli/genetics , Shiga-Toxigenic Escherichia coli/pathogenicity , Virulence , Whole Genome Sequencing
5.
Biometrics ; 76(4): 1310-1318, 2020 12.
Article in English | MEDLINE | ID: mdl-32002993

ABSTRACT

Individualized treatment rules (ITRs) recommend treatments based on patient-specific characteristics in order to maximize the expected clinical outcome. At the same time, the risks caused by various adverse events cannot be ignored. In this paper, we propose a method to estimate an optimal ITR that maximizes clinical benefit while having the overall risk controlled at a desired level. Our method works for a general setting of multi-category treatment. The proposed procedure employs two shifted ramp losses to approximate the 0-1 loss in the objective function and constraint, respectively, and transforms the estimation problem into a difference of convex functions (DC) programming problem. A relaxed DC algorithm is used to solve the nonconvex constrained optimization problem. Simulations and a real data example are used to demonstrate the finite sample performance of the proposed method.


Subject(s)
Algorithms , Precision Medicine , Humans , Research Design
6.
Inorg Chem ; 59(11): 7752-7760, 2020 Jun 01.
Article in English | MEDLINE | ID: mdl-32432856

ABSTRACT

Concentration quenching of upconversion (UC) luminescence (UCL) is a common phenomenon in rare-earth-doped materials that seriously restricts the concentration of the activator and sensitizer and withholds their UC emissions and quantum yields. In particular, it remains a tremendous challenge to develop one novel strategy based on the introduction of trivalent bismuth (Bi3+) ions to exceed the typical thulium (Tm3+) ion concentration and reach high-efficiency UC under low illumination. In this work, the Tm3+ accommodation capacity can be increased from 2.0 to 8.0 mol % in NaYbF4:Tm3+ materials with the assistance of Bi3+ ions, which maintains strong UC emissions with large absolute UC quantum yields under low illumination. Specifically, the total upconversion quantum yield (UCQY) of the as-obtained Na(Tm0.08Yb0.60Bi0.32)F4 (8Tm60Yb32Bi) sample can reach as high as 1.45% upon continuous-wave (CW) laser excitation at 40 W cm-2. Strikingly, the total UCQY still remains at a high level (0.41%) even though the CW power density decreases to 1.5 W cm-2. Moreover, the intrinsic mechanism of the breakthrough in the threshold of concentration quenching of UCL by Bi3+ ions was also fully explored. These advances in enhancing UC emissions and UCQYs under a low pump power density offer exciting opportunities for important photonic applications.

7.
Biometrics ; 75(4): 1216-1227, 2019 12.
Article in English | MEDLINE | ID: mdl-31095722

ABSTRACT

Individualized treatment regimes (ITRs) aim to recommend treatments based on patient-specific characteristics in order to maximize the expected clinical outcome. Outcome weighted learning approaches have been proposed for this optimization problem with primary focus on the binary treatment case. Many require assumptions of the outcome value or the randomization mechanism. In this paper, we propose a general framework for multicategory ITRs using generic surrogate risk. The proposed method accommodates the situations when the outcome takes negative value and/or when the propensity score is unknown. Theoretical results about Fisher consistency, excess risk, and risk consistency are established. In practice, we recommend using differentiable convex loss for computational optimization. We demonstrate the superiority of the proposed method under multinomial deviance risk to some existing methods by simulation and application on data from a clinical trial.


Subject(s)
Machine Learning , Models, Statistical , Precision Medicine/methods , Algorithms , Clinical Trials as Topic , Computer Simulation , Humans , Risk , Treatment Outcome
8.
J Biol Chem ; 288(32): 23038-49, 2013 Aug 09.
Article in English | MEDLINE | ID: mdl-23798684

ABSTRACT

Regulation of inwardly rectifying potassium channels by intracellular ligands couples cell membrane excitability to important signaling cascades and metabolic pathways. We investigated the molecular mechanisms that link ligand binding to the channel gate in ATP-sensitive Kir6.2 channels. In these channels, the "slide helix" forms an interface between the cytoplasmic (ligand-binding) domain and the transmembrane pore, and many slide helix mutations cause loss of function. Using a novel approach to rescue electrically silent channels, we decomposed the contribution of each interface residue to ATP-dependent gating. We demonstrate that effective inhibition by ATP relies on an essential aspartate at residue 58. Characterization of the functional importance of this conserved aspartate, relative to other residues in the slide helix, has been impossible because of loss-of-function of Asp-58 mutant channels. The Asp-58 position exhibits an extremely stringent requirement for aspartate because even a highly conservative mutation to glutamate is insufficient to restore normal channel function. These findings reveal unrecognized slide helix elements that are required for functional channel expression and control of Kir6.2 gating by intracellular ATP.


Subject(s)
Adenosine Triphosphate/metabolism , Potassium Channels, Inwardly Rectifying/metabolism , Adenosine Triphosphate/genetics , Amino Acid Substitution , Animals , Cell Line , Mice , Mutation, Missense , Potassium Channels, Inwardly Rectifying/chemistry , Potassium Channels, Inwardly Rectifying/genetics , Protein Structure, Secondary
9.
PLoS One ; 19(3): e0299354, 2024.
Article in English | MEDLINE | ID: mdl-38483966

ABSTRACT

The goal of this study is to investigate the origin, prevalence, and evolution of the pESI megaplasmid in Salmonella isolated from animals, foods, and humans. We queried 510,097 Salmonella genomes under the National Center for Biotechnology Information (NCBI) Pathogen Detection (PD) database for the presence of potential sequences containing the pESI plasmid in animal, food, and environmental sources. The presence of the pESI megaplasmid was confirmed by using seven plasmid-specific markers (rdA, pilL, SogS, TrbA, ipf, ipr2 and IncFIB(pN55391)). The plasmid and chromosome phylogeny of these isolates was inferred from single nucleotide polymorphisms (SNPs). Our search resolved six Salmonella clusters carrying the pESI plasmid. Four were emergent Salmonella Infantis clusters, and one each belonged to serovar Senftenberg and Alachua. The Infantis cluster with a pESI plasmid carrying blaCTX-M-65 gene was the biggest of the four emergent Infantis clusters, with over 10,000 isolates. This cluster was first detected in South America and has since spread widely in United States. Over time the composition of pESI in United States has changed with the average number of resistance genes showing a decrease from 9 in 2014 to 5 in 2022, resulting from changes in gene content in two integrons present in the plasmid. A recent and emerging cluster of Senftenberg, which carries the blaCTX-M-65 gene and is primarily associated with turkey sources, was the second largest in the United States. SNP analysis showed that this cluster likely originated in North Carolina with the recent acquisition of the pESI plasmid. A single Alachua isolate from turkey was also found to carry the pESI plasmid containing blaCTX-M-65 gene. The study of the pESI plasmid, its evolution and mechanism of spread can help us in developing appropriate strategies for the prevention and further spread of this multi-drug resistant plasmid in Salmonella in poultry and humans.


Subject(s)
Salmonella enterica , Humans , Animals , United States , Serogroup , Anti-Bacterial Agents/pharmacology , Cephalosporin Resistance/genetics , Chickens/genetics , Virulence/genetics , Salmonella , Plasmids/genetics , Drug Resistance, Multiple, Bacterial/genetics
10.
mBio ; 15(7): e0077724, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38920393

ABSTRACT

This study examined the diversity and persistence of Salmonella in the surface waters of agricultural regions of Brazil, Chile, and Mexico. Research groups (three in 2019-2020 and five in 2021-2022) conducted a long-term survey of surface water across 5-8 months annually (n = 30 monthly). On-site, each team filtered 10-L water samples with modified Moore Swabs to capture Salmonella, which were then isolated and identified using conventional microbiological techniques. Salmonella isolates were sequenced on Illumina platforms. Salmonella was present in 1,493/3,291 water samples (45.8%), with varying isolation rates across countries and years. Newport, Infantis, and Typhimurium were the most frequent among the 128 different serovars. Notably, 22 serovars were found in all three countries, representing almost half of the 1,911 different isolates collected. The resistome comprised 72 antimicrobial resistance (AMR) genes and six point mutations in three genes. At least one AMR determinant was observed in 33.8% (646/1,911) of the isolates, of which 47.4% (306/646) were potentially multidrug resistant. Phylogeny based on core genome multilocus sequence typing (cgMLST) showed that most isolates clustered according to sequence type and country of origin. Only 14 cgMLST multi-country clusters were detected among the 275 clusters. However, further analysis confirmed that close genetic relatedness occurred mostly among isolates from the same country, with three exceptions. Interestingly, isolates closely related phylogenetically were recovered over multiple years within the same country, indicating the persistence of certain Salmonella in those areas. In conclusion, surface waters in these regions are consistently contaminated with diverse Salmonella, including strains that persist over time.IMPORTANCESalmonella is a leading foodborne pathogen responsible for millions of illnesses, hospitalizations, and deaths annually. Although Salmonella-contaminated water has now been recognized as an important contamination source in the agrifood chain, there is a lack of knowledge on the global occurrence and diversity of Salmonella in surface water. Moreover, there has been insufficient research on Salmonella in surface waters from Latin American countries that are major producers and exporters of agricultural products. Incorporating genetic profiling of Salmonella isolates from underrepresented regions, such as Latin America, enhances our understanding of the pathogen's ecology, evolution, antimicrobial resistance, and pathogenicity. Moreover, leveraging genomic data derived from pathogens isolated from diverse geographical areas is critical for assessing the potential public health risk posed by the pathogen and expediting investigations of foodborne outbreaks. Ultimately, global efforts contribute significantly to reducing the incidence of foodborne infections.


Subject(s)
Salmonella , Water Microbiology , Brazil/epidemiology , Salmonella/genetics , Salmonella/classification , Salmonella/isolation & purification , Mexico/epidemiology , Chile/epidemiology , Genetic Variation , Phylogeny , Genome, Bacterial , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/genetics , Genomics , Molecular Epidemiology
11.
Microbiol Spectr ; 12(5): e0004724, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38546218

ABSTRACT

Surface waters are considered ecological habitats where Salmonella enterica can persist and disseminate to fresh produce production systems. This study aimed to explore the genomic profiles of S. enterica serotypes Typhimurium, Newport, and Infantis from surface waters in Chile, Mexico, and Brazil collected between 2019 and 2022. We analyzed the whole genomes of 106 S. Typhimurium, 161 S. Newport, and 113 S. Infantis isolates. Our phylogenetic analysis exhibited distinct groupings of isolates by their respective countries except for a notable case involving a Chilean S. Newport isolate closely related to two Mexican isolates, showing 4 and 13 single nucleotide polymorphisms of difference, respectively. The patterns of the most frequently detected antimicrobial resistance genes varied across countries and serotypes. A strong correlation existed between integron carriage and genotypic multidrug resistance (MDR) across serotypes in Chile and Mexico (R > 0.90, P < 0.01), while integron(s) were not detected in any of the Brazilian isolates. By contrast, we did not identify any strong correlation between plasmid carriage and genotypic MDR across diverse countries and serotypes.IMPORTANCEUnveiling the genomic landscape of S. enterica in Latin American surface waters is pivotal for ensuring public health. This investigation sheds light on the intricate genomic diversity of S. enterica in surface waters across Chile, Mexico, and Brazil. Our research also addresses critical knowledge gaps, pioneering a comprehensive understanding of surface waters as a reservoir for multidrug-resistant S. enterica. By integrating our understanding of integron carriage as biomarkers into broader MDR control strategies, we can also work toward targeted interventions that mitigate the emergence and dissemination of MDR in S. enterica in surface waters. Given its potential implications for food safety, this study emphasizes the critical need for informed policies and collaborative initiatives to address the risks associated with S. enterica in surface waters.


Subject(s)
Drug Resistance, Multiple, Bacterial , Phylogeny , Salmonella enterica , Salmonella typhimurium , Serogroup , Salmonella enterica/genetics , Salmonella enterica/isolation & purification , Salmonella enterica/classification , Salmonella enterica/drug effects , Brazil , Drug Resistance, Multiple, Bacterial/genetics , Mexico , Salmonella typhimurium/genetics , Salmonella typhimurium/isolation & purification , Salmonella typhimurium/drug effects , Salmonella typhimurium/classification , Integrons/genetics , Genome, Bacterial , Chile , Genomics , Anti-Bacterial Agents/pharmacology , Latin America , Water Microbiology , Polymorphism, Single Nucleotide , Plasmids/genetics , Microbial Sensitivity Tests
12.
mBio ; 14(1): e0345522, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36645293

ABSTRACT

Phylogeny is a powerful tool that can be incorporated into quantitative descriptions of community diversity, yet its use has been limited largely due to the difficulty in constructing phylogenies which incorporate the wide genomic diversity of microbial communities. Here, we describe the development of a web portal, PhyloPlus, which enables users to generate customized phylogenies that may be applied to any bacterial or archaeal communities. We demonstrate the power of phylogeny by comparing metrics that employ phylogeny with those that do not when applied to data sets from two metagenomic studies (fermented food, n = 58; human microbiome, n = 60). This example shows how inclusion of all bacterial species identified by taxonomic classifiers (Kraken2 and Kaiju) made the phylogeny perfectly congruent to the corresponding classification outputs. Our phylogeny-based approach also enabled the construction of more constrained null models which (i) shed light into community structure and (ii) minimize potential inflation of type I errors. Construction of such null models allowed for the observation of under-dispersion in 44 (75.86%) food samples, with the metacommunity defined as bacteria that were found in different food matrices. We also observed that closely related species with high abundance and uneven distribution across different sites could potentially exaggerate the dissimilarity between phylogenetically similar communities if they were measured using traditional species-based metrics (Padj. = 0.003), whereas this effect was mitigated by incorporating phylogeny (Padj. = 1). In summary, our tool can provide additional insights into microbial communities of interest and facilitate the use of phylogeny-based approaches in metagenomic analyses. IMPORTANCE There has been an explosion of interest in how microbial diversity affects human health, food safety, and environmental functions among many other processes. Accurately measuring the diversity and structure of those communities is central to understanding their effects. Here, we describe the development of a freely available online tool, PhyloPlus, which allows users to generate custom phylogenies that may be applied to any data set, thereby removing a major obstacle to the application of phylogeny to metagenomic data analysis. We demonstrate that the genetic relatedness of the organisms within those communities is a critical feature of their overall diversity, and that using a phylogeny which captures and quantifies this diversity allows for much more accurate descriptions while preventing misleading conclusions based on estimates that ignore evolutionary relationships.


Subject(s)
Metagenome , Microbiota , Humans , Phylogeny , Metagenomics , Microbiota/genetics , Bacteria/genetics , RNA, Ribosomal, 16S/genetics
13.
J Clin Transl Hepatol ; 11(4): 877-888, 2023 Aug 28.
Article in English | MEDLINE | ID: mdl-37408809

ABSTRACT

Background and Aims: Aminoacyl-tRNA synthetases (ARSs) participate in tumor initiation and progression but their involvement in hepatocellular carcinoma (HCC) is not clear. This study aimed to investigate the prognostic value and underlying mechanisms of ARS in HCC. Methods: Data were obtained from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium, Gene Expression Omnibus and Human Protein Atlas databases. The prognostic model was constructed with the use of Cox regression and least absolute shrinkage and selection operator regression. Kaplan-Meier survival analysis, enrichment analysis, single sample gene set enrichment analysis and tumor mutation burden calculation were performed with R to evaluate the model and explore the underlying mechanism. Wilcoxon tests were used for comparisons between groups. Results: Aspartyl-tRNA synthetase 2 (DARS2), tyrosyl-tRNA synthetase 1 (YARS1) and cysteinyl-tRNA synthetase 2 (CARS2) were identified as prognostic biomarkers and enrolled in model construction. The area under receiver operating characteristic curve of the model was 0.775. The model was used to assign patients from TCGA into low- and high-risk groups. Those in the high-risk group had a worse prognosis (p<0.001). The clinical significance of the model was tested in different clinical subgroups. Genetic mutation analysis had a higher TP53 mutation frequency in high-risk group. Enrichment analysis and study of immune-related cells and molecules found that the high-risk group was characterized by immune-cell infiltration and immunosuppression states. Conclusions: A novel ARS family-based model of HCC prognosis was constructed. TP53 mutation frequency and immune-suppressive status accounted for a worse prognosis in patients included in the high-risk group.

14.
Plant Physiol Biochem ; 204: 108071, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37922647

ABSTRACT

When attempting to maximize the crop yield from field-grown soybean (Glycine max (L.) Merr.) by means of improving the light conditions for photosynthesis in the canopy, it is crucial to find the optimal planting density and nitrogen application rate. The soybean plants that were the subject of our experiment were cultivated in N-dense mutual pairs, and included two cultivars with different leaf shapes; one cultivar sported ovate leaves (O-type) and the other lanceolate leaves (L-type). We analyzed the results quantitatively to determine the amount of spatial variation in light distribution and photosynthetic efficiency across the canopy, and to gauge the effect of the experimental parameters on the yield as well as the photosynthetic light and nitrogen use efficiency of the crop. Results indicate that the different leaf shapes were responsible for significant disparities between the photosynthetic utilization of direct and diffuse light. As the nitrogen fertilizer rate and the planting density increased, the soybean plants responded by adjusting leaf morphology in order to maximize the canopy apparent photosynthetic light use efficiency, which in turn affected the leaf nitrogen distribution in the canopy. Despite the fact that the light interception rate of the canopy of the L-type cultivar was lower than that of the canopy of the O-type cultivar, we found its canopy apparent photosynthetic nitrogen and light use efficiency were higher. It was interesting to note, however, that the nitrogen and light use efficiency contributions associated with exposure to diffuse light were greater for the latter than for the former.


Subject(s)
Glycine max , Nitrogen , Photosynthesis , Plant Leaves , Light
15.
J Biol Chem ; 286(42): 36686-93, 2011 Oct 21.
Article in English | MEDLINE | ID: mdl-21878633

ABSTRACT

Numerous inwardly rectifying potassium (Kir) channels possess an aromatic residue in the helix bundle crossing region, forming the narrowest pore constriction in crystal structures. However, the role of the Kir channel bundle crossing as a functional gate remains uncertain. We report a unique phenotype of Kir6.2 channels mutated to encode glutamate at this position (F168E). Despite a prediction of four glutamates in close proximity, Kir6.2(F168E) channels are predominantly closed at physiological pH, whereas alkalization causes rapid and reversible channel activation. These findings suggest that F168E glutamates are uncharged at physiological pH but become deprotonated at alkaline pH, forcing channel opening due to mutual repulsion of nearby negatively charged side chains. The potassium channel pore scaffold likely brings these glutamates close together, causing a significant pK(a) shift relative to the free side chain (as seen in the KcsA selectivity filter). Alkalization also shifts the apparent ATP sensitivity of the channel, indicating that forced motion of the bundle crossing is coupled to the ATP-binding site and may resemble conformational changes involved in wild-type Kir6.2 gating. The study demonstrates a novel mechanism for engineering extrinsic control of channel gating by pH and shows that conformational changes in the bundle crossing region are involved in ligand-dependent gating of Kir channels.


Subject(s)
Ion Channel Gating/physiology , Potassium Channels, Inwardly Rectifying/metabolism , Amino Acid Substitution , Animals , Cell Line , Hydrogen-Ion Concentration , Mice , Mutation, Missense , Potassium Channels, Inwardly Rectifying/chemistry , Potassium Channels, Inwardly Rectifying/genetics , Protein Conformation , Xenopus laevis
16.
Front Oncol ; 12: 827051, 2022.
Article in English | MEDLINE | ID: mdl-35433491

ABSTRACT

Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant disease with a poor prognosis. More effective biomarkers and treatment options remain to be discovered. Mitotic Spindle Positioning (MISP), also called C19orf21, has been reported to be upregulated in several malignancies. However, the effects of MISP on PDAC have yet to be investigated. Materials and Methods: The differential expression of MISP at the mRNA and protein levels were evaluated using Gene Expression Profiling Interactive Analysis 2 (GEPIA 2), Gene Expression Omnibus (GEO), and the Human Protein Atlas (HPA) databases, and was further verified by quantitative real-time PCR and western blotting in PDAC cell lines. Correlations between MISP expression and clinical characteristics were explored using Kaplan-Meier Plotter Database and clinical data from The Cancer Genome Atlas (TCGA). CCK-8 assays, Transwell assays, and immunoblotting were used to determine the role of MISP in PDAC proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were executed by the R package 'clusterProfiler'. Correlations between MISP expression and immune cell infiltration, immune checkpoints, immunophenoscore (IPS) and the tumor mutational burden (TMB) in PDAC were explored using the R package 'CIBERSORT', the Tumor Immune Estimation Resource 2.0 (TIMER2.0), and The Cancer Immunome Atlas (TCIA) database based on TCGA data. Result: MISP expression was significantly higher in pancreatic cancer tissues compared to normal pancreas tissues, which was associated with a poor prognosis. Increased expression of MISP was related to the proliferation, migration and invasion of PDAC cell lines. GO and KEGG pathway analyses determined that MISP is involved in the Ras signaling pathway and immune regulation. Higher expression of MISP was associated with decreased infiltration levels of activated CD4+ memory T cells, CD8+ T cells, M2 macrophages and neutrophils. Furthermore, increased MISP was associated with lower expression of immune checkpoint molecules, higher gene mutation burden and IPS. Conclusions: This study reveals that MISP, which is associated with the progression and prognosis of PDAC, may exert a potential regulatory effect on immune infiltration and predict the response to immunotherapy in PDAC.

17.
Oncol Lett ; 20(5): 146, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32934714

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease, which frequently presents with distant metastasis. Further understanding of the molecular mechanism of PDAC is helpful to uncover novel and effective therapeutic strategies. DEP domain containing 1B (DEPDC1B) is known to play a role in the carcinogenesis and metastasis of several common types of cancer; however, its biological function and molecular mechanism in PDAC progression remain unclear. In the present study, the expression levels of DEPDC1B were detected in 79 pairs of PDAC and adjacent non-cancerous tissues. Patients with PDAC that exhibited higher DEPDC1B expression levels, were shown to have a poorer prognosis. Functional studies showed that knocking down DEPDC1B inhibited PDAC cell migration and invasion, while overexpressing DEPDC1B promoted these processes. Western blotting analysis and immunofluorescence demonstrated that DEPDC1B overexpression induced the epithelial-to-mesenchymal transition (EMT). Further mechanistic studies revealed that DEPDC1B was able to activate the Akt/glycogen synthase kinase-3ß (GSK3ß)/Snail signaling pathway. In conclusion, the results of the present study showed that DEPDC1B may serve as an oncogene that contributes to PDAC cell migration and invasion by inducing EMT via Akt/GSK3ß/Snail pathway activation.

18.
PLoS One ; 12(2): e0172106, 2017.
Article in English | MEDLINE | ID: mdl-28207889

ABSTRACT

The mini core collection (MCC) has been established by streamlining core collection (CC) chosen from China National Genebank including 23,587 soybean (Glycine max) accessions by morphological traits and simple sequence repeat (SSR) markers. Few studies have been focused on the maturity that has been considered as one of the most critical traits for the determination of the adaptation-growing region of the soybean. In the current study, two hundred and ninty-nine accessions of MCC planted for two years at four locations namely in Heihe, Harbin, Jining and Wuhan cities in China were used to assess the variation of maturity in MCC and identify the integrated effect of 4 E loci on flowering and maturity time in soybean. Forty-two North American varieties served as references of maturity groups (MG). Each accession in MCC was classified by comparing with the MG references in the days from VE (emergence) and physiological maturity (R7). The results showed that MCC covered a large range of MGs from MG000 to MGIX/X. Original locations and sowing types were revealed as the major affecting factors for maturity groups of the MCC accessions. The ratio of the reproductive period to the vegetative period (R/V) varied among MCC accessions. Genotyping of 4 maturity genes (i.e. E1, E2, E3 and E4) in 228 accessions indicated that recessive alleles e1, e2, e3 and e4 promoted earlier flowering and shortened the maturity time with different effects, while the dominate alleles were always detected in accessions with longer maturity. The allelic combinations determined the diversification of soybean maturity groups and adaptation to different regions. Our results indicated that the maturity of Chinese soybean MCC showed genetic diversities in phenotype and genotype, which provided information for further MG classification, geographic adaptation analysis of Chinese soybean cultivars, as well as developing new soybean varieties with adaptation to specific regions.


Subject(s)
Flowers/genetics , Genetic Variation/genetics , Glycine max/genetics , Microsatellite Repeats/genetics , Plant Proteins/genetics , China , Chromosome Mapping , Flowers/growth & development , Gene Expression Regulation, Plant , Genotype , Phenotype , Quantitative Trait Loci , Glycine max/growth & development
19.
Saudi J Biol Sci ; 20(1): 23-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23961215

ABSTRACT

In this study, the gfp fragment as a reporter gene had integrated into the form plasmid vector pBC-hygro which contains an expressive promoter of the fungus to facilitate the transformation of Fusarium oxysporum. The resultant plasmid pBC-hygro-GFP was identified by digestion with enzymes. Binary plasmids pBC-hygro-GFP were transformed into F. oxysporum by using the PEG-CaCl2 mediated transformation technique. Results show that the recombinant plasmid pBC-hygro-GFP was constructed correctly. The gfp gene was stably maintained and did not convey any significant loss of phenotype which would affect the survival and behaviour of the tagged strains. Introduction of the gfp gene into F. oxysporum provides a simple, specific and cost-effective method of strain identification for ecological studies. Transcriptional reporter vectors were constructed for using the green fluorescent protein (GFP) reporter.

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