Identification of liver cancer progenitors whose malignant progression depends on autocrine IL-6 signaling.

Hepatocellular carcinoma (HCC) is a slowly developing malignancy postulated to evolve from premalignant lesions in chronically damaged livers. However, it was never established that premalignant lesions actually contain tumor progenitors that give rise to cancer. Here, we describe isolation and characterization of HCC progenitor cells (HcPCs) from different mouse HCC models. Unlike fully malignant HCC, HcPCs give rise to cancer only when introduced into a liver undergoing chronic damage and compensatory proliferation. Although HcPCs exhibit a similar transcriptomic profile to bipotential hepatobiliary progenitors, the latter do not give rise to tumors. Cells resembling HcPCs reside within dysplastic lesions that appear several months before HCC nodules. Unlike early hepatocarcinogenesis, which depends on paracrine IL-6 production by inflammatory cells, due to upregulation of LIN28 expression, HcPCs had acquired autocrine IL-6 signaling that stimulates their in vivo growth and malignant progression. This may be a general mechanism that drives other IL-6-producing malignancies.

New insight into the agonism of protease-activated receptors as an immunotherapeutic strategy.

The activation and mobilization of immune cells play a crucial role in immunotherapy. Existing therapeutic interventions, such as cytokines administration, aim to enhance immune cell activity. However, these approaches usually result in modest effectiveness and toxic side effects, thereby restricting their clinical application. Protease-activated receptors (PARs), a subfamily of G protein-coupled receptors, actively participate in the immune system by directly activating immune cells. The activation of PARs by proteases or synthetic ligands can modulate immune cell behavior, signaling, and responses to treat immune-related diseases, suggesting the significance of PARs agonism in immunotherapy. However, the agonism of PARs in therapeutical applications remains rarely discussed, since it has been traditionally considered that PARs activation facilitates disease progressions. This review aims to comprehensively summarize the activation, rather than inhibition, of PARs in immune-related physiological responses and diseases. Additionally, we will discuss the emerging immunotherapeutic potential of PARs agonism, providing a new strategic direction for PARs-mediated immunotherapy.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms.

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

scHiCStackL: a stacking ensemble learning-based method for single-cell Hi-C classification using cell embedding.

Single-cell Hi-C data are a common data source for studying the differences in the three-dimensional structure of cell chromosomes. The development of single-cell Hi-C technology makes it possible to obtain batches of single-cell Hi-C data. How to quickly and effectively discriminate cell types has become one hot research field. However, the existing computational methods to predict cell types based on Hi-C data are found to be low in accuracy. Therefore, we propose a high accuracy cell classification algorithm, called scHiCStackL, based on single-cell Hi-C data. In our work, we first improve the existing data preprocessing method for single-cell Hi-C data, which allows the generated cell embedding better to represent cells. Then, we construct a two-layer stacking ensemble model for classifying cells. Experimental results show that the cell embedding generated by our data preprocessing method increases by 0.23, 1.22, 1.46 and 1.61$\%$ comparing with the cell embedding generated by the previously published method scHiCluster, in terms of the Acc, MCC, F1 and Precision confidence intervals, respectively, on the task of classifying human cells in the ML1 and ML3 datasets. When using the two-layer stacking ensemble framework with the cell embedding, scHiCStackL improves by 13.33, 19, 19.27 and 14.5 over the scHiCluster, in terms of the Acc, ARI, NMI and F1 confidence intervals, respectively. In summary, scHiCStackL achieves superior performance in predicting cell types using the single-cell Hi-C data. The webserver and source code of scHiCStackL are freely available at http://hww.sdu.edu.cn:8002/scHiCStackL/ and https://github.com/HaoWuLab-Bioinformatics/scHiCStackL, respectively.

Impact of cell wall polysaccharide modifications on the performance of Pichia pastoris: novel mutants with enhanced fitness and functionality for bioproduction applications.

BACKGROUND: Pichia pastoris is a widely utilized host for heterologous protein expression and biotransformation. Despite the numerous strategies developed to optimize the chassis host GS115, the potential impact of changes in cell wall polysaccharides on the fitness and performance of P. pastoris remains largely unexplored. This study aims to investigate how alterations in cell wall polysaccharides affect the fitness and function of P. pastoris, contributing to a better understanding of its overall capabilities. RESULTS: Two novel mutants of GS115 chassis, H001 and H002, were established by inactivating the PAS_chr1-3_0225 and PAS_chr1-3_0661 genes involved in ß-glucan biosynthesis. In comparison to GS115, both modified hosts exhibited a looser cell surface and larger cell size, accompanied by faster growth rates and higher carbon-to-biomass conversion ratios. When utilizing glucose, glycerol, and methanol as exclusive carbon sources, the carbon-to-biomass conversion rates of H001 surpassed GS115 by 10.00%, 9.23%, and 33.33%, respectively. Similarly, H002 exhibited even higher increases of 32.50%, 12.31%, and 53.33% in carbon-to-biomass conversion compared to GS115 under the same carbon sources. Both chassis displayed elevated expression levels of green fluorescent protein (GFP) and human epidermal growth factor (hegf). Compared to GS115/pGAPZ A-gfp, H002/pGAPZ A-gfp showed a 57.64% higher GFP expression, while H002/pPICZα A-hegf produced 66.76% more hegf. Additionally, both mutant hosts exhibited enhanced biosynthesis efficiencies of S-adenosyl-L-methionine and ergothioneine. H001/pGAPZ A-sam2 synthesized 21.28% more SAM at 1.14 g/L compared to GS115/pGAPZ A-sam2, and H001/pGAPZ A-egt1E obtained 45.41% more ERG at 75.85 mg/L. The improved performance of H001 and H002 was likely attributed to increased supplies of NADPH and ATP. Specifically, H001 and H002 exhibited 5.00-fold and 1.55-fold higher ATP levels under glycerol, and 6.64- and 1.47-times higher ATP levels under methanol, respectively, compared to GS115. Comparative lipidomic analysis also indicated that the mutations generated richer unsaturated lipids on cell wall, leading to resilience to oxidative damage. CONCLUSIONS: Two novel P. pastoris chassis hosts with impaired ß-1,3-D-glucan biosynthesis were developed, showcasing enhanced performances in terms of growth rate, protein expression, and catalytic capabilities. These hosts exhibit the potential to serve as attractive alternatives to P. pastoris GS115 for various bioproduction applications.

Kinesin family member 11 promotes progression of hepatocellular carcinoma via the OCT4 pathway.

Hepatocellular carcinoma (HCC) is the tumor with the second highest mortality rate worldwide. Recent research data show that KIF11, a member of the kinesin family (KIF), plays an important role in the progression of various tumors. However, its expression and molecular mechanism in HCC remain elusive. Here, we evaluated the potential role of KIF11 in HCC. The effect of KIF11 was evaluated using the hepatocellular carcinoma cell lines, LM3 and Huh7, after genetic or pharmacological treatment. Evaluating the role of KIF11 in the xenograft animal models using its specific inhibitor. The role of KIF11 was systematically evaluated using specimens obtained from the aforementioned animal and cell models after various in vivo and in vitro experiments. The clinicopathological analysis showed that KIF11 was expressed at high levels in patients with hepatocellular carcinoma. Cell experiments in vitro showed that KIF11 deficiency significantly slowed the proliferation of liver tumor cells. And in the experiment using liver cancer cells overexpressing OCT4, overexpression of OCT4 substantially increased the proliferation of tumor cells compared with tumor cells with KIF11 knockdown alone. Both in vitro cell experiment and in vivo xenotransplantation tumor experiment showed that monastrol, an inhibitor of KIF11, could effectively delay the proliferation and migration of tumor cells. Based on these results, KIF11 is expressed at high levels in hepatocellular carcinoma and promotes tumor proliferation in an OCT4-dependent manner. KIF11 may become a therapeutic target for hepatocellular carcinoma, and its inhibitor monastrol may become a clinical antitumor drug.

Identification and validation of core genes in tumor-educated platelets for human gastrointestinal tumor diagnosis using network-based transcriptomic analysis.

Gastrointestinal (GI) tumors have increasing incidence worldwide with their underlying mechanisms still not being fully understood. The use of tumor-educated platelets (TEPs) in liquid biopsy is a newly-emerged blood-based cancer diagnostic method. Herein, we aimed to investigate the genomic changes of TEPs in GI tumor development and their potential functions using network-based meta-analysis combined with bioinformatic methods. We used a total of three eligible RNA-seq datasets, which were integrated using multiple meta-analysis methods on the NetworkAnalyst website, and identified 775 DEGs (differentially expressed genes; 51 up-regulated and 724 down-regulated genes) in GI tumor relative to healthy control (HC) samples. These TEP DEGs were mostly enriched in bone marrow-derived cell types and associated with gene ontology (GO) of "carcinoma" and could affect pathways of "Integrated Cancer Pathway" and "Generic transcription pathway" respectively for highly and lowly expressed DEGs. Combined network-based meta-analysis and protein-protein interaction (PPI) analysis identified cyclin dependent kinase 1 (CDK1) and heat shock protein family A (Hsp70) member 5 (HSPA5) to be the hub genes with the highest degree centrality (DC), being up-regulated and down-regulated in TEPs, respectively. GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that the hub genes were primarily related to cell cycle and division, nucleobase-containing compound and carbohydrate transport, and endoplasmic reticulum unfolded protein response. Additionally, the nomogram model suggested that the two-gene signature owns extraordinary predictive power for GI tumor diagnosis. Further, the two-gene signature was demonstrated to have potential value for metastatic GI tumor diagnosis. The expression levels of CDK1 and HSPA5 in clinical platelet samples were verified to be consistent with the results from bioinformatic analysis. This study identified a two-gene signature encompassing CDK1 and HSPA5 that can be used as a biomarker for GI tumor diagnosis and maybe even cancer-associated thrombosis (CAT)-related prognosis.

What is the context? Gastrointestinal (GI) tumors are now responsible for the majority of cancer-related mortalities worldwide.In the majority of cases of cancer, curative treatments are not recommended at the time of diagnosis. In this case, early screening and diagnosis is very important for overall tumor prognosis. Liquid biopsy emerged as a newly introduced minimally invasive approach for cancer diagnosis by detecting blood analytes as tumor-educated platelets (TEPs). Compared to tissue-based biopsies, liquid biopsies are less invasive, easy to access, convenient for serial tracking and better in eliminating intratumoral spatial heterogeneity. In recent years, specific gene signatures have been identified for cancer diagnosis, prognosis and prediction based on gene profiling data of TEPs. However, most of these studies were performed on the independent platelet profile datasets published on the Gene Expression Omnibus (GEO) database, which may harbor enormous heterogeneity. Additionally, few study revealed TEP mRNA functions and roles in GI tumors. Therefore, there's the need of using an integrated method to re-analyze these data, so we can gain new insights for GI tumor diagnosis.What is new? Herein, through network-based RNA-seq meta-analysis, we identified the CDK1-HSPA5 signature in TEPs that has the potential as a biomarker for diagnosing GI tumors. This is the first time, to our knowledge, that a shared transcriptional signature of tumor-educated platelets has been identified in human GI tumor patients based on meta-analysis. Additionally, we found the two-gene signature has potential value for metastatic GI tumor diagnosis. We also demonstrated that HSPA5 may have different roles in blood and tumor cells, so its expression deregulation in distinct types of tissue may have opposing diagnostic and prognostic values.What is the impact? Our work provides a novel biomarker for platelet-based GI tumor prediction and diagnosis, which may also be used as novel targets for thrombosis prevention during cancer development in the future.

Residential surrounding greenness is associated with improved lung function in adults: a cross-sectional study in eastern China.

BACKGROUND: While benefits of greenness exposure to health have been reported, findings specific to lung function are inconsistent. The purpose of this study is to assess the correlations of greenness exposure with multiple lung function indicators based on chronic obstructive pulmonary disease (COPD) monitoring database from multiple cities of Anhui province in China. METHODS: We assessed the greenness using the annual average of normalized difference vegetation index (NDVI) with a distance of 1000-meter buffer around each local community or village. Three types of lung function indicators were considered, namely indicators of obstructive ventilatory dysfunction (FVC, FEV1, FEV1/FVC, and FEV1/FEV3); an indicator of large-airway dysfunction (PEF); indicators of small-airway dysfunction (FEF25%, FEF50%, FEF75%, MMEF, FEV3, FEV6, and FEV3/FVC). Linear mixed effects model was used to analyze associations of greenness exposure with lung function through adjusting age, sex, educational level, occupation, residence, smoking status, history of tuberculosis, family history of lung disease, indoor air pollution, occupational exposure, PM2.5, and body mass index. RESULTS: A total of 2768 participants were recruited for the investigations. An interquartile range (IQR) increase in NDVI was associated with better FVC (153.33mL, 95%CI: 44.07mL, 262.59mL), FEV1 (109.09mL, 95%CI: 30.31mL, 187.88mL), FEV3 (138.04mL, 95%CI: 39.43mL, 236.65mL), FEV6 (145.42mL, 95%CI: 42.36mL, 248.47mL). However, there were no significant associations with PEF, FEF25%, FEF50%, FEF75%, MMEF, FEV1/FVC, FEV1/FEV6, FEV3/FVC. The stratified analysis displayed that an IQR increase in NDVI was related with improved lung function in less than 60 years, females, urban populations, nonsmokers, areas with medium concentrations of PM2.5 and individuals with BMI of less than 28 kg/m2. Sensitivity analyses based on another greenness indice (enhanced vegetation index, EVI) and annual maximum of NDVI remained consistent with the main analysis. CONCLUSIONS: Our findings supported that exposure to greenness was strongly related with improved lung function.

3D matrix promotes cell dedifferentiation into colorectal cancer stem cells via integrin/cytoskeleton/glycolysis signaling.

The potential for tumor occurrence triggered by cancer stem cells (CSCs) has emerged as a significant challenge for human colorectal cancer therapy. However, the underlying mechanism of CSC development remains controversial. Our study provided evidence that the bulk of tumor cells could dedifferentiate to CSCs and reacquire CSC-like phenotypes if cultured in the presence of extracellular matrix reagents, such as Matrigel and fibrin gels. In these 3D gels, CD133- colorectal cancer cells can regain tumorigenic potential and stem-like phenotypes. Mechanistically, the 3D extracellular matrix could mediate cytoskeletal F-actin bundling through biomechanical force associated receptors integrin ß1 (ITGB1), contributing to the release of E3 ligase tripartite motif protein 11 (TRIM11) from cytoskeleton and degradation of the glycolytic rate-limiting enzyme phosphofructokinase (PFK). Consequently, PFK inhibition resulted in enhanced glycolysis and upregulation of hypoxia-inducible factor 1 (HIF1α), thereby promoting the reprogramming of stem cell transcription factors and facilitating tumor progression in patients. This study provided novel insights into the role of the extracellular matrix in the regulation of CSC dedifferentiation in a cytoskeleton/glycolysis-dependent manner.

Probing Friction Properties of Hydrogen-Free DLC Films in a Nitrogen Environment Based on ReaxFF Molecular Dynamics.

In this paper, ReaxFF molecular dynamics simulations were used to look at how load and the number of nitrogen molecules affect how friction behavior in hydrogen-free diamond-like carbon (DLC). The presence of nitrogen molecules will inhibit the formation of C-C covalent bonds between the contact surfaces of the upper and lower DLC, thereby effectively suppressing the increase in friction during the initial friction phase. After the initial friction stage, the mechanical mixing of the contact surfaces brought on by the diffusion of nitrogen molecules results in considerable shear stress, which has significant impacts on the friction force. In addition, due to the existence of nitrogen molecules, the effect of graphitization of hydrogen-free DLC on friction is almost negligible.

Quantum Chemical Prediction of the Acidities of Sulfonamide Inhibitors of Carbonic Anhydrase.

This study examined two pKa calculation approaches (direct and proton exchange schemes) that employ high-level quantum chemical methods and implicit solvent models to predict aqueous Brønsted acidities of a large set of sulfonamides. For gas-phase deprotonation energies, the DSD-PBEP86-D3(BJ) double-hybrid functional provided the best agreement with the LNO-CCSD(T)/CBS benchmark with a mean absolute deviation less than 2 kJ mol-1 when the aug-cc-pVTZ or larger basis sets are used. For a large test set of 54 primary and secondary sulfonamides, the use of the DSD-PBEP86-D3(BJ)/aug-cc-pVTZ level of theory in conjunction with SM12 solvation free energies predict their pKa values with a mean accuracy of 0.9 units. In comparison, the SMD and ADF-COSMO-RS models have slightly higher mean errors of 1.4 and 1.1 pKa units provided that the proton exchange scheme was employed to cancel the systematic errors in these models. The performance of these protocols was less ideal when applied to sulfonic acids, sulfamates, and N-substituted sulfonamides, indicating that the degree of error cancellation is sensitive to the chemical environment around the -NH2 head group. The validated protocols were then used to estimate the pKa values of arylsulfonamide carbonic anhydrase inhibitors, which are used to correct their experimentally measured binding free energies to account for deprotonation of the sulfonamide group upon binding to the enzyme. These corrected values did not have a significant impact on the correlation with MMGBSA binding free energies obtained from classical MD simulations where the ligand is usually considered in the deprotonated form.

Inhibitor of apoptosis-stimulating p53 protein protects against inflammatory bowel disease in mice models by inhibiting the nuclear factor kappa B signaling.

Drugs and therapies available for the treatment of inflammatory bowel disease (IBD) are not satisfactory. Our previous study has established the inhibitor of apoptosis-stimulating p53 protein (iASPP) as an oncogenic regulator in colorectal cancer by forming a regulatory axis or feedback loop with miR-124, p53, or p63. As iASPP could target and inhibit nuclear factor kappa B (NF-κB) activation, in this study the role and mechanism of iASPP in IBD was investigated. The aberrant up-regulation of iASPP in IBD was subsequently confirmed, based on online data sets, clinical sample examinations and 2,4,6-trinitrobenzene sulfonic acid (TNBS)- and dextran sulfate sodium (DSS)-induced colitis mice models. TNBS or DSS stimulation successfully induced colon shortness, body weight loss, mice colon oxidative stress and inflammation. In both types of colitis mice models, iASPP over-expression improved, whereas iASPP knockdown aggravated TNBS or DSS stimulation-caused colon shortness, body weight loss and mice colon oxidative stress and inflammation. Meanwhile, in both types of colitis mice models, iASPP over-expression inhibited p65 phosphorylation and decreased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, C-X-C motif chemokine ligand (CXCL)1 and CXCL2 in mice colons, whereas iASPP knockdown exerted opposite effects.

Elevated glycosylated hemoglobin levels and their interactive effects on hypertension risk in nondiabetic Chinese population: a cross-sectional survey.

BACKGROUND: Abnormal glucose metabolism has been suggested to be involved in the development of hypertension. This study investigated the effect of the association and potential interaction of glycosylated hemoglobin (HbA1c) and other factors on the risk of hypertension among Chinese nondiabetic adults. METHODS: As a cross-sectional survey, the current work deployed a questionnaire survey, anthropometric tests, and biochemical measures for each of the eligible participants. The HbA1c levels were quantified and grouped by quartiles. Correlations between HbA1c and hypertension, isolated systolic hypertension (ISH), and isolated diastolic hypertension (IDH) risk were investigated by logistic analyses. For evaluating the interactive effects, the parameters of relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP), and synergy index (SI) were calculated, respectively. RESULTS: In the current study, 1462 nondiabetic subjects were enrolled. In total, the prevalence rates of hypertension, ISH and IDH were 22.4, 9.6 and 4.5%, respectively. When HbA1c levels were grouped by quartile, it was revealed that the prevalence rates of hypertension and ISH were substantially elevated across groups (Pfor trend < 0.001). In the multivariable logistic regression analyses, in comparison with the first quartile of HbA1c, the normalized OR for hypertension risk was 1.90 (95% CI: 1.28-2.80) for the highest quartile. Also, the risk of ISH was significantly increased with HbA1c level in the highest quartile relative to in the bottom quartile (OR: 2.23,95% CI:1.47-3.71). However, no significant relationship between the HbA1c level and IDH risk was observed (OR: 1.78, 95% CI: 0.82-3.84). Eventually, it was demonstrated from the interactive effect analysis that HbA1c significantly interacted with abdominal obesity (RERI: 1.48, 95% CI: 0.38-2.58; AP: 0.37, 95% CI: 0.14-0.60 and SI: 1.96, 95% CI: 1.06-3.62) and family history of hypertension (AP: 0.37, 95% CI: 0.05-0.70) in influencing the risk of hypertension in nondiabetic participants. CONCLUSION: Higher HbA1c levels significantly enhanced the risk of hypertension and ISH, but not IDH among Chinese nondiabetic adults. Moreover, the risk of hypertension was also aggravated by the upregulated HbA1c in a synergistic manner alongside abdominal obesity and family history of hypertension.

A Potent Antagonist of Protease-Activated Receptor 2 That Inhibits Multiple Signaling Functions in Human Cancer Cells.

Protease-activated receptor 2 (PAR2) is a cell surface protein linked to G-protein dependent and independent intracellular signaling pathways that produce a wide range of physiological responses, including those related to metabolism, inflammation, pain, and cancer. Certain proteases, peptides, and nonpeptides are known to potently activate PAR2. However, no effective potent PAR2 antagonists have been reported yet despite their anticipated therapeutic potential. This study investigates antagonism of key PAR2-dependent signaling properties and functions by the imidazopyridazine compound I-191 (4-(8-(tert-butyl)-6-(4-fluorophenyl)imidazo[1,2-b]pyridazine-2-carbonyl)-3,3-dimethylpiperazin-2-one) in cancer cells. At nanomolar concentrations, I-191 inhibited PAR2 binding of and activation by structurally distinct PAR2 agonists (trypsin, peptide, nonpeptide) in a concentration-dependent manner in cells of the human colon adenocarcinoma grade II cell line (HT29). I-191 potently attenuated multiple PAR2-mediated intracellular signaling pathways leading to Ca2+ release, extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, Ras homologue gene family, member A (RhoA) activation, and inhibition of forskolin-induced cAMP accumulation. The mechanism of action of I-191 was investigated using binding and calcium mobilization studies in HT29 cells where I-191 was shown to be noncompetitive and a negative allosteric modulator of the agonist 2f-LIGRL-NH2 The compound alone did not activate these PAR2-mediated pathways, even at high micromolar concentrations, indicating no bias in these signaling properties. I-191 also potently inhibited PAR2-mediated downstream functional responses, including expression and secretion of inflammatory cytokines and cell apoptosis and migration, in human colon adenocarcinoma grade II cell line (HT29) and human breast adenocarcinoma cells (MDA-MB-231). These findings indicate that I-191 is a potent PAR2 antagonist that inhibits multiple PAR2-induced signaling pathways and functional responses. I-191 may be a valuable tool for characterizing PAR2 functions in cancer and in other cellular, physiological, and disease settings.

Rapid and selective updating of the target template in visual search.

Frequent target stimuli are detected more rapidly than infrequent ones. Here, we examined whether the frequency effect reflected durable attentional biases toward frequent target features, and whether the effect was confined to featural properties that defined the target. Participants searched for two specific target colors among distractors of heterogeneous colors and reported the line orientation of the target. The target was more often in one specific feature (e.g., a specific color or a specific orientation) than another in a training phase. This frequency difference was removed or reversed in a testing phase. Experiments 1 and 2 showed that when frequency differences were introduced to the target's defining feature, participants more rapidly found the high-frequency target than the low-frequency target. However, changes in attention were not durable-the search advantage vanished immediately when the frequency differences were removed. Experiments 3-5 showed that only featural properties that defined the target facilitated search of the more frequent feature. Features that did not define the target, such as the target feature that participants reported, sped up response but did not facilitate search. These data showed that when searching for multiple targets in a feature search task, people selectively and rapidly adapt to the frequency in the target's defining feature.

Identification and Characterization of Lipopolysaccharide Induced TNFα Factor from Blunt Snout Bream, Megalobrama amblycephala.

Lipopolysaccharide induced TNFα factor (LITAF) is an important transcription factor responsible for regulation of tumor necrosis factor α. In this study, a novel litaf gene (designated as Malitaf) was identified and characterized from blunt snout bream, Megalobrama amblycephala. The full-length cDNA of Malitaf was of 956 bp, encoding a polypeptide of 161 amino acids with high similarity to other known LITAFs. A phylogenetic tree also showed that Malitaf significantly clustered with those of other teleost, indicating that Malitaf was a new member of fish LITAF family. The putative maLITAF protein possessed a highly conserved LITAF domain with two CXXC motifs. The mRNA transcripts of Malitaf were detected in all examined tissues of healthy M. amblycephala, including kidney, head kidney, muscle, liver, spleen, gill, and heart, and with the highest expression in immune organs: spleen and head kidney. The expression level of Malitaf in spleen was rapidly up-regulated and peaked (1.29-fold, p < 0.05) at 2 h after lipopolysaccharide (LPS) stimulation. Followed the stimulation of Malitaf, Matnfα transcriptional level was also transiently induced to a high level (51.74-fold, p < 0.001) at 4 h after LPS stimulation. Taken together, we have identified a putative fish LITAF ortholog, which was a constitutive and inducible immune response gene involved in M. amblycephala innate immunity during the course of a pathogenic infection.

Intranasal Vaccination against HIV-1 with Adenoviral Vector-Based Nanocomplex Using Synthetic TLR-4 Agonist Peptide as Adjuvant.

Recombinant type 5 adenovirus (rAd5) vaccines hold the promise to prevent HIV-1 infections. Intranasal vaccination not only stimulates systemic immunity but also elicits mucosal immunity that provides first defense for mucosally transmitted diseases like HIV-1. Adjuvants such as TLR agonists are usually codelivered with antigens to enhance the immunogenicity of vaccines. Here, we present a rAd5 vaccine delivery system using DEG-PEI as the carrier. Adenovirus encoding HIV gag was used as antigen, and was complexed with DEG-PEI polymer via electrostatic interaction. A novel synthetic TLR-4 agonist, RS09, was either chemically linked with DEG-PEI (DP-RS09) or physically mixed with it(DP/RS09) to enhance the immunogenticity of rAd5 vaccine. After intranasal immunization, the systemic antigen-specific immune responses and cytotoxicity T lymphocytes responses induced by DP-RS09-rAd5 and DP/RS09-rAd5 were analyzed. The mucosal secretory IgA level was detected in both nasal and vaginal washes to determine the mucosal immunity. Furthermore, cytokine productions on RAW264.7 cells were tested after preincubation with TLR-4 pathway inhibitors. The results indicated that DEG-PEI could facilitate the intranasal delivery of rAd5 vaccine. Both chemically linked (DP-RS09) and physically mixed RS09 (DP/RS09) could further enhance the mucosal immunity of rAd5 vaccine via TLR-4 pathway. This RS09 adjuvanted DEG-PEI polymer represents a potential intranasal vaccine delivery system and may have a wider application for other viral vectors.

Identification and characterization of a novel Toll-like receptor 4 homologue in blunt snout bream, Megalobrama amblycephala.

Toll-like receptors (TLRs) are central players in the innate immune system in response to a wide range of pathogen infection. Among various TLRs, TLR4 plays a key role in recognition of bacterial lipopolysaccharides (LPS). In the present study, we identified and characterized a novel TLR4 homologue (maTLR4b) in blunt snout bream (Megalobrama amblycephala) which was significantly distinct from previously reported M. amblycephala TLR4 (tentatively named maTLR4a). The results showed that the complete cDNA sequence of maTLR4b was 3261 bp with an open reading frame encoding a polypeptide of 820 amino acids, and that its genomic sequence was 3793 bp, which had 3 exons. Structurally, the deduced maTLR4b protein showed a typical TLR domain architecture, including a signal peptide, eight leucine-rich repeats (LRRs) in the extracellular region, a transmembrane domain, and a Toll-Interleukin 1 receptor (TIR) domain in the cytoplasmic region. Phylogenetic analysis revealed that all TLR4s from teleost fish formed a monophyletic clade. Both maTLR4a and maTLR4b were divided into two distinct branches, and showed the highest level of similarity with the grass carp TLR4.2 and TLR4.4 homologue, respectively. MaTLR4b was constitutively expressed in all healthy tissues tested although at different levels. After LPS stimulation, the expression levels were significantly up-regulated in spleen, and peaked at 4 h between maTLR4a and maTLR4b, but with a distinct and complementary expression patterns. Taken together, these results suggested that maTLR4b is indeed a functional homologue of TLR4 in other species, which may play vital role in innate immune.

Identification and expression analysis on bactericidal permeability-increasing protein/lipopolysaccharide-binding protein of blunt snout bream, Megalobrama amblycephala.

Bactericidal permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP) belong to the lipid transfer protein/lipopolysaccharide-binding protein family and play a critical role in the innate immune response to Gram-negative bacteria. In the present study, a novel BPI/LBP from blunt snout bream, Megalobrama amblycephala (maBPI/LBP) was isolated by RACE techniques. The open reading frame (ORF) of maBPI/LBP gene encoded a polypeptide of 474 amino acids with a putative 18-aa hydrophobic signal peptide. Structurally, the maBPI/LBP showed highly similar to those of BPI/LBPs from invertebrate and teleost, LBPs and BPIs from mammal, which contained an N-terminal BPI/LBP/CETP domain BPI1 with a LPS-binding domain, a C-terminal BPI/LBP/CETP domain BPI2, and proline-rich domain. The homologous identities of deduced amino acid sequences displayed that the maBPI/LBP possessed significant similarity (96.61% and 90.07%) with those of grass carp and common carp, respectively. The recombinant protein of maBPI/LBP showed effectively kill Gram-negative bacteria. The maBPI/LBP gene was expressed in a wide range of normal tested tissues, with the highest expression levels in the kidney. The experiments revealed that the mRNA expression of maBPI/LBP in spleen considerably up-regulated from 2 h to 8 h post LPS stimulation, and peaked rapidly at 2 h (7.40-fold, P < 0.05), which confirmed that maBPI/LBP was the absolute sensitive to LPS stimulation. Furthermore, the level of maBPI/LBP mRNA expression reached the maximum for a second time at 24 h after LPS stimulation. These results suggested that maBPI/LBP was a constitutive and inducible acute-phase protein contributing to the host immune defense against pathogenic bacterial infection in M. amblycephala. This study will further our understanding of the function of BPI/LBP and the molecular mechanism of innate immunity in teleost.

Repurposing Registered Drugs as Antagonists for Protease-Activated Receptor 2.

Virtual screening of a drug database identified Carvedilol, Loratadine, Nefazodone and Astemizole as PAR2 antagonists, after ligand docking and molecular dynamics simulations using a PAR2 homology model and a putative binding mode of a known PAR2 ligand. The drugs demonstrated competitive binding and antagonism of calcium mobilization and ERK1/2 phosphorylation in CHO-hPAR2 transfected cells, while inhibiting IL-6 secretion in PAR2 expressing MDA-MB-231 breast cancer cells. This research highlights opportunities for GPCR hit-finding from FDA-approved drugs.