Assessment of chemotherapy resistance changes in human colorectal cancer xenografts in rats based on MRI histogram features.

Purpose: We investigated the value of magnetic resonance imaging (MRI) histogram features, a non-invasive method, in assessing the changes in chemoresistance of colorectal cancer xenografts in rats. Methods: A total of 50 tumor-bearing mice with colorectal cancer were randomly divided into two groups: control group and 5-fluorouracil (5-FU) group. The MRI histogram characteristics and the expression levels of p53 protein and MRP1 were obtained at 24 h, 48 h, 72 h, 120 h, and 168 h after treatment. Results: Sixty highly repeatable MRI histogram features were obtained. There were 16 MRI histogram parameters and MRP1 resistance protein differences between groups. At 24 h after treatment, the MRI histogram texture parameters of T2-weighted imaging (T2WI) images (10%, 90%, median, energy, and RootMeanSquared) and D images (10% and Range) were positively correlated with MRP1 (r = 0.925, p = 0.005). At 48 h after treatment, histogram texture parameters of apparent diffusion coefficient (ADC) images (Energy) were positively correlated with the presence of MRP1 resistance protein (r = 0.900, p = 0.037). There was no statistically significant difference between MRI histogram features and p53 protein expression level. Conclusions: MRI histogram texture parameters based on T2WI, D, and ADC maps can help to predict the change of 5-FU resistance in colorectal cancer in the early stage and provide important reference significance for clinical treatment.

Mitochondria-targeted fluorophores for in vivo NIR-II imaging-guided PDT/PTT.

A simple yet powerful D-A type-based NIR-II fluorophore (MTF) with mitochondria targeting was constructed. This mitochondrial targeting dye MTF exhibited not only a photothermal effect but also photodynamic performance, and was further fabricated with DSPE-mPEG to generate nanodots for in vivo experiments, achieving strong NIR-II fluorescence tracing of tumors and impressive NIR-II image-guided photodynamic therapy (PDT) and photothermal therapy (PTT).

Chaotic Mapping-Based Anti-Sorting Radio Frequency Stealth Signals and Compressed Sensing-Based Echo Signal Processing Technology.

Radio frequency (RF) stealth anti-sorting technology can improve the battlefield survival rate of radar and is one of the research hotspots in the radar field. In this study, the signal design principle of anti-sequential difference histogram (SDIF) sorting was explored for the main sorting algorithm of the SDIF. Furthermore, we designed a piecewise linear chaotic system with interval number parameterization based on random disturbance and proposed a method to modulate the repetition period of widely spaced signal pulses using a chaotic system. Then, considering the difficulty of the traditional signal processing method to measure the velocity of the highly random anti-sorting signals designed in this paper, we used compressed sensing (CS) technology to process the echoes of the signals to solve the velocity and distance of the detection targets. Finally, simulation verification was performed from the correctness of the signal design principle, the performance of the chaotic system, the anti-sorting performance of the designed signals and the recovery and reconstruction performance of the signals by CS. The results show that: (a) the signal design principle presented in this paper can guide the signal design correctly; (b) the performance of the piecewise linear chaotic system with interval number parameterization is better than that of the classical one-dimensional chaotic system; (c) the anti-sorting signal modulated by the chaotic system can achieve anti-SDIF sorting, and the anti-sorting signals designed in this paper can be processed to obtain the velocity and distance of the targets.

Development and validation of a prognostic nomogram for predicting cancer-specific survival in patients with metastatic clear cell renal carcinoma: A study based on SEER database.

Objectives: Clear cell renal cell carcinoma (ccRCC) is highly prevalent, prone to metastasis, and has a poor prognosis after metastasis. Therefore, this study aimed to develop a prognostic model to predict the individualized prognosis of patients with metastatic clear cell renal cell carcinoma (mccRCC). Patients and Methods: Data of 1790 patients with mccRCC, registered from 2010 to 2015, were extracted from the Surveillance, Epidemiology and End Results (SEER) database. The included patients were randomly divided into a training set (n = 1253) and a validation set (n = 537) based on the ratio of 7:3. The univariate and multivariate Cox regression analyses were used to identify the important independent prognostic factors. A nomogram was then constructed to predict cancer specific survival (CSS). The performance of the nomogram was internally validated by using the concordance index (C-index), calibration plots, receiver operating characteristic curves, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). We compared the nomogram with the TNM staging system. Kaplan-Meier survival analysis was applied to validate the application of the risk stratification system. Results: Diagnostic age, T-stage, N-stage, bone metastases, brain metastases, liver metastases, lung metastases, chemotherapy, radiotherapy, surgery, and histological grade were identified as independent predictors of CSS. The C-index of training and validation sets are 0.707 and 0.650 respectively. In the training set, the AUC of CSS predicted by nomogram in patients with mccRCC at 1-, 3- and 5-years were 0.770, 0.758, and 0.757, respectively. And that in the validation set were 0.717, 0.700, and 0.700 respectively. Calibration plots also showed great prediction accuracy. Compared with the TNM staging system, NRI and IDI results showed that the predictive ability of the nomogram was greatly improved, and DCA showed that patients obtained clinical benefits. The risk stratification system can significantly distinguish the patients with different survival risks. Conclusion: In this study, we developed and validated a nomogram to predict the CSS rate in patients with mccRCC. It showed consistent reliability and clinical applicability. Nomogram may assist clinicians in evaluating the risk factors of patients and formulating an optimal individualized treatment strategy.

Influenza A virus activates cellular Tropomyosin receptor kinase A (TrkA) signaling to promote viral replication and lung inflammation.

Influenza A virus (IAV) infection causes acute respiratory disease with potential severe and deadly complications. Viral pathogenesis is not only due to the direct cytopathic effect of viral infections but also to the exacerbated host inflammatory responses. Influenza viral infection can activate various host signaling pathways that function to activate or inhibit viral replication. Our previous studies have shown that a receptor tyrosine kinase TrkA plays an important role in the replication of influenza viruses in vitro, but its biological roles and functional mechanisms in influenza viral infection have not been characterized. Here we show that IAV infection strongly activates TrkA in vitro and in vivo. Using a chemical-genetic approach to specifically control TrkA kinase activity through a small molecule compound 1NMPP1 in a TrkA knock-in (TrkA KI) mouse model, we show that 1NMPP1-mediated TrkA inhibition completely protected mice from a lethal IAV infection by significantly reducing viral loads and lung inflammation. Using primary lung cells isolated from the TrkA KI mice, we show that specific TrkA inhibition reduced IAV viral RNA synthesis in airway epithelial cells (AECs) but not in alveolar macrophages (AMs). Transcriptomic analysis confirmed the cell-type-specific role of TrkA in viral RNA synthesis, and identified distinct gene expression patterns under the TrkA regulation in IAV-infected AECs and AMs. Among the TrkA-activated targets are various proinflammatory cytokines and chemokines such as IL6, IL-1ß, IFNs, CCL-5, and CXCL9, supporting the role of TrkA in mediating lung inflammation. Indeed, while TrkA inhibitor 1NMPP1 administered after the peak of IAV replication had no effect on viral load, it was able to decrease lung inflammation and provided partial protection in mice. Taken together, our results have demonstrated for the first time an important biological role of TrkA signaling in IAV infection, identified its cell-type-specific contribution to viral replication, and revealed its functional mechanism in virus-induced lung inflammation. This study suggests TrkA as a novel host target for therapeutic development against influenza viral disease.

Value of IVIM in Differential Diagnoses between Benign and Malignant Solitary Lung Nodules and Masses: A Meta-analysis.

Purpose: This study aims to evaluate the accuracy of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in distinguishing malignant and benign solitary pulmonary nodules and masses. Methods: Studies investigating the diagnostic accuracy of IVIM-DWI in lung lesions published through December 2020 were searched. The standardized mean differences (SMDs) of the apparent diffusion coefficient (ADC), tissue diffusivity (D), pseudo-diffusivity (D*), and perfusion fraction (f) were calculated. The sensitivity, specificity, area under the curve (AUC), publication bias, and heterogeneity were then summarized, and the source of heterogeneity and the reliability of combined results were explored by meta-regression and sensitivity analysis. Results: A total of 16 studies including 714 malignant and 355 benign lesions were included. Significantly lower ADC, D, and f values were found in malignant pulmonary lesions compared to those in benign lesions. The D value showed the best diagnostic performance (sensitivity = 0.90, specificity = 0.71, AUC = 0.91), followed by ADC (sensitivity = 0.84, specificity = 0.75, AUC = 0.88), f (sensitivity = 0.70, specificity = 0.62, AUC = 0.71), and D * (sensitivity = 0.67, specificity = 0.61, AUC = 0.67). There was an inconspicuous publication bias in ADC, D, D* and f values, moderate heterogeneity in ADC, and high heterogeneity in D, D*, and f values. Subgroup analysis suggested that both ADC and D values had a significant higher sensitivity in "nodules or masses" than that in "nodules." Conclusions: The parameters derived from IVIM-DWI, especially the D value, could further improve the differential diagnosis between malignant and benign solitary pulmonary nodules and masses.Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier: CRD42021226664.

Resveratrol in Intestinal Health and Disease: Focusing on Intestinal Barrier.

The integrity of intestinal barrier determines intestinal homeostasis, which could be affected by various factors, like physical, chemical, and biological stimuli. Therefore, it is of considerable interest and importance to maintain intestinal barrier function. Fortunately, many plant polyphenols, including resveratrol, could affect the health of intestinal barrier. Resveratrol has many biological functions, such as antioxidant, anti-inflammation, anti-tumor, and anti-cardiovascular diseases. Accumulating studies have shown that resveratrol affects intestinal tight junction, microbial composition, and inflammation. In this review, we summarize the effects of resveratrol on intestinal barriers as well as the potential mechanisms (e.g., inhibiting the growth of pathogenic bacteria and fungi, regulating the expression of tight junction proteins, and increasing anti-inflammatory T cells while reducing pro-inflammatory T cells), and highlight the applications of resveratrol in ameliorating various intestinal diseases.

Progress of proteomics-driven precision medicine: From a glycosylation view.

Currently, cancer is one of the leading causes of death worldwide, partially owing to the lack of early diagnosis methods and effective therapies. With the rapid development of various omics, the precision medicine strategy becomes a promising way to increase the survival rates by considering individual differences. Glycosylation is one of the most essential protein post-translational modifications and plays important roles in a variety of biological processes. Therefore, it is highly possible to acquire understanding of the molecular mechanisms as well as discover novel potential markers for diagnosis and prognosis based on glycoproteomics research. This review summarizes the recent glycoproteomics studies about N-glycosylation of several cancer types, mainly in the past 5 years. We also highlight corresponding mass spectrometry-based analytical methods to give a brief overview on the main techniques applied in glycoproteomics.

A transcriptomic analysis based on aberrant methylation levels revealed potential novel therapeutic targets for nasopharyngeal carcinoma.

Background: This study aimed to identify potential novel therapeutic targets for nasopharyngeal carcinoma (NPC) by identifying aberrantly methylated-differentially expressed genes (DEGs) and pathways based on a comprehensive bioinformatics analysis. Methods: Eight gene expression data sets and 2 methylation microarray data sets that included NPC and control groups from the Gene Expression Omnibus were identified. Meta-analyses of the DEGs were performed using the online analysis database "NetworkAnalyst". Aberrantly methylated gene loci were obtained from the GEO2R. Aberrantly methylated DEGs were obtained from Venn diagrams. The enrichment analysis was carried out on the "Metascape" website, and the protein-protein interaction (PPI) network construction, network analysis, and visualization of the analysis results were carried out on the "String" website using "Cytoscape" software. Results: In total, 544 hypomethylation high-expression genes and 164 hypermethylation low-expression genes were obtained. The enrichment and PPI network analyses suggested that several pathways and hub genes with abnormal gene expression accompanied by methylation change, including inositol-trisphosphate 3-kinase B (ITPKB), G protein subunit beta 5 (GNB5), FYN proto-oncogene, Src family tyrosine kinase (FYN), LCK proto-oncogene, Src family tyrosine kinase (LCK), nuclear factor of activated T cells 1 (NFATC1), GNAS complex locus (GNAS), protein kinase C beta (PRKCB), zeta chain of T cell receptor associated protein kinase 70 (ZAP70), lysophosphatidic acid receptor 1 (LPAR1), protein kinase C epsilon (PRKCE), tumor protein p53 (TP53), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), fibronectin 1 (FN1), cyclin D1 (CCND1), vascular endothelial growth factor A (VEGFA), HRas proto-oncogene, GTPase (HRAS), signal transducer and activator of transcription 3 (STAT3), fibroblast growth factor 2 (FGF2), amyloid beta precursor protein (APP), and matrix metallopeptidase 2 (MMP2), may be related to the occurrence of nasopharyngeal carcinoma . Conclusions: The identification of novel and important pathways and hub genes and their roles in the occurrence and development of NPC will guide clinical research and the development of pharmaceutical targets.

RIG-I and MDA5 Protect Mice From Pichinde Virus Infection by Controlling Viral Replication and Regulating Immune Responses to the Infection.

RIG-I and MDA5 are major cytoplasmic innate-immune sensor proteins that recognize aberrant double-stranded RNAs generated during virus infection to activate type 1 interferon (IFN-I) and IFN-stimulated gene (ISG) expressions to control virus infection. The roles of RIG-I and MDA5 in controlling replication of Pichinde virus (PICV), a mammarenavirus, in mice have not been examined. Here, we showed that MDA5 single knockout (SKO) and RIG-I/MDA5 double knockout (DKO) mice are highly susceptible to PICV infection as evidenced by their significant reduction in body weights during the course of the infection, validating the important roles of these innate-immune sensor proteins in controlling PICV infection. Compared to the wildtype mice, SKO and DKO mice infected with PICV had significantly higher virus titers and lower IFN-I expressions early in the infection but appeared to exhibit a late and heightened level of adaptive immune responses to clear the infection. When a recombinant rPICV mutant virus (rPICV-NPmut) that lacks the ability to suppress IFN-I was used to infect mice, as expected, there were heightened levels of IFN-I and ISG expressions in the wild-type mice, whereas infected SKO and DKO mice showed delayed mouse growth kinetics and relatively low, delayed, and transient levels of innate and adaptive immune responses to this viral infection. Taken together, our data suggest that PICV infection triggers activation of immune sensors that include but might not be necessarily limited to RIG-I and MDA5 to stimulate effective innate and adaptive immune responses to control virus infection in mice.

Pre-operative Prediction of Ki-67 Expression in Various Histological Subtypes of Lung Adenocarcinoma Based on CT Radiomic Features.

Purpose: The aims of this study were to combine CT images with Ki-67 expression to distinguish various subtypes of lung adenocarcinoma and to pre-operatively predict the Ki-67 expression level based on CT radiomic features. Methods: Data from 215 patients with 237 pathologically proven lung adenocarcinoma lesions who underwent CT and immunohistochemical Ki-67 from January 2019 to April 2021 were retrospectively analyzed. The receiver operating curve (ROC) identified the Ki-67 cut-off value for differentiating subtypes of lung adenocarcinoma. A chi-square test or t-test analyzed the differences in the CT images between the negative expression group (n = 132) and the positive expression group (n = 105), and then the risk factors affecting the expression level of Ki-67 were evaluated. Patients were randomly divided into a training dataset (n = 165) and a validation dataset (n = 72) in a ratio of 7:3. A total of 1,316 quantitative radiomic features were extracted from the Analysis Kinetics (A.K.) software. Radiomic feature selection and radiomic classifier were generated through a least absolute shrinkage and selection operator (LASSO) regression and logistic regression analysis model. The predictive capacity of the radiomic classifiers for the Ki-67 levels was investigated through the ROC curves in the training and testing groups. Results: The cut-off value of the Ki-67 to distinguish subtypes of lung adenocarcinoma was 5%. A comparison of clinical data and imaging features between the two groups showed that histopathological subtypes and air bronchograms could be used as risk factors to evaluate the expression of Ki-67 in lung adenocarcinoma (p = 0.005, p = 0.045, respectively). Through radiomic feature selection, eight top-class features constructed the radiomic model to pre-operatively predict the expression of Ki-67, and the area under the ROC curves of the training group and the testing group were 0.871 and 0.8, respectively. Conclusion: Ki-67 expression level with a cut-off value of 5% could be used to differentiate non-invasive lung adenocarcinomas from invasive lung adenocarcinomas. It is feasible and reliable to pre-operatively predict the expression level of Ki-67 in lung adenocarcinomas based on CT radiomic features, as a non-invasive biomarker to predict the degree of malignant invasion of lung adenocarcinoma, and to evaluate the prognosis of the tumor.

Inhibition of Arenaviruses by Combinations of Orally Available Approved Drugs.

Neglected diseases caused by arenaviruses such as Lassa virus (LASV) and filoviruses like Ebola virus (EBOV) primarily afflict resource-limited countries, where antiviral drug development is often minimal. Previous studies have shown that many approved drugs developed for other clinical indications inhibit EBOV and LASV and that combinations of these drugs provide synergistic suppression of EBOV, often by blocking discrete steps in virus entry. We hypothesize that repurposing of combinations of orally administered approved drugs provides effective suppression of arenaviruses. In this report, we demonstrate that arbidol, an approved influenza antiviral previously shown to inhibit EBOV, LASV, and many other viruses, inhibits murine leukemia virus (MLV) reporter viruses pseudotyped with the fusion glycoproteins (GPs) of other arenaviruses (Junin virus [JUNV], lymphocytic choriomeningitis virus [LCMV], and Pichinde virus [PICV]). Arbidol and other approved drugs, including aripiprazole, amodiaquine, sertraline, and niclosamide, also inhibit infection of cells by infectious PICV, and arbidol, sertraline, and niclosamide inhibit infectious LASV. Combining arbidol with aripiprazole or sertraline results in the synergistic suppression of LASV and JUNV GP-bearing pseudoviruses. This proof-of-concept study shows that arenavirus infection in vitro can be synergistically inhibited by combinations of approved drugs. This approach may lead to a proactive strategy with which to prepare for and control known and new arenavirus outbreaks.

Chinese doctors' views on workplace-based assessment: trainee and supervisor perspectives of the mini-CEX.

Purpose: This study investigated whether the mini-clinical evaluation exercise (mini-CEX) has been successfully integrated into the Chinese context, following its introduction as part of the national general training programme. Materials and methods: Online questionnaires (N = 91) and interviews (N = 22) were conducted with Year 1 trainee doctors and clinical supervisors at a cancer hospital in China to explore users' experiences, attitudes and opinions of the mini-CEX. Results" Trainees were more likely than supervisors to report understanding the purpose of the mini-CEX and agree that it encouraged reflection and helped improve overall performance. Both trainees and supervisors felt that it provided a framework for learning, that it was useful in identifying underperformance, and that it informed learning progression. Groups were equally positive about the commitment of their counterpart in the process and valued the focus on detailed feedback. It was perceived as cultivating the learner-teacher relationship. Overall, both groups felt they 'bought in' to using the mini-CEX. However, concerns were raised about subjectivity of ratings and lack of benchmarking with expected standards of care. Conclusions: Chinese trainees and supervisors generally perceived the mini-CEX as an acceptable and valuable medical training tool, although both groups suggested enhancements to improve its efficacy.

Development and Applications of Viral Vectored Vaccines to Combat Zoonotic and Emerging Public Health Threats.

Vaccination is arguably the most cost-effective preventative measure against infectious diseases. While vaccines have been successfully developed against certain viruses (e.g., yellow fever virus, polio virus, and human papilloma virus HPV), those against a number of other important public health threats, such as HIV-1, hepatitis C, and respiratory syncytial virus (RSV), have so far had very limited success. The global pandemic of COVID-19, caused by the SARS-CoV-2 virus, highlights the urgency of vaccine development against this and other constant threats of zoonotic infection. While some traditional methods of producing vaccines have proven to be successful, new concepts have emerged in recent years to produce more cost-effective and less time-consuming vaccines that rely on viral vectors to deliver the desired immunogens. This review discusses the advantages and disadvantages of different viral vaccine vectors and their general strategies and applications in both human and veterinary medicines. A careful review of these issues is necessary as they can provide important insights into how some of these viral vaccine vectors can induce robust and long-lasting immune responses in order to provide protective efficacy against a variety of infectious disease threats to humans and animals, including those with zoonotic potential to cause global pandemics.

Emerging Concepts and Technologies in Vaccine Development.

Despite the success of vaccination to greatly mitigate or eliminate threat of diseases caused by pathogens, there are still known diseases and emerging pathogens for which the development of successful vaccines against them is inherently difficult. In addition, vaccine development for people with compromised immunity and other pre-existing medical conditions has remained a major challenge. Besides the traditional inactivated or live attenuated, virus-vectored and subunit vaccines, emerging non-viral vaccine technologies, such as viral-like particle and nanoparticle vaccines, DNA/RNA vaccines, and rational vaccine design, offer innovative approaches to address existing challenges of vaccine development. They have also significantly advanced our understanding of vaccine immunology and can guide future vaccine development for many diseases, including rapidly emerging infectious diseases, such as COVID-19, and diseases that have not traditionally been addressed by vaccination, such as cancers and substance abuse. This review provides an integrative discussion of new non-viral vaccine development technologies and their use to address the most fundamental and ongoing challenges of vaccine development.

Effect of Strain Variations on Lassa Virus Z Protein-Mediated Human RIG-I Inhibition.

Mammarenaviruses include several known human pathogens, such as the prototypic lymphocytic choriomeningitis virus (LCMV) that can cause neurological diseases and Lassa virus (LASV) that causes endemic hemorrhagic fever infection. LASV-infected patients show diverse clinical manifestations ranging from asymptomatic infection to hemorrhage, multi-organ failures and death, the mechanisms of which have not been well characterized. We have previously shown that the matrix protein Z of pathogenic arenaviruses, including LASV and LCMV, can strongly inhibit the ability of the innate immune protein RIG-I to suppress type I interferon (IFN-I) expression, which serves as a mechanism of viral immune evasion and virulence. Here, we show that Z proteins of diverse LASV isolates derived from rodents and humans have a high degree of sequence variations at their N- and C-terminal regions and produce variable degrees of inhibition of human RIG-I (hRIG-I) function in an established IFN-ß promoter-driven luciferase (LUC) reporter assay. Additionally, we show that Z proteins of four known LCMV strains can also inhibit hRIG-I at variable degrees of efficiency. Collectively, our results confirm that Z proteins of pathogenic LASV and LCMV can inhibit hRIG-I and suggest that strain variations of the Z proteins can influence their efficiency to suppress host innate immunity that might contribute to viral virulence and disease heterogeneity.

Intervertebral disc degeneration associated with vertebral marrow fat, assessed using quantitative magnetic resonance imaging.

OBJECTIVE: To investigate the potential clinical application of quantitative MRI in assessing the correlation between lumbar vertebrae bone marrow fat deposition and intervertebral disc degeneration. MATERIALS AND METHODS: A total of 104 chronic lower-back pain volunteers underwent 3.0-T MRI with T2-weighted imaging, T2 mapping, and iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL-IQ) between August 2018 and June 2019. Each disc was assessed with T2 value by T2 mapping, and the L1-S1 vertebral bone marrow fat fraction was assessed by IDEAL-IQ. The differences and relationship between T2 value and the adjacent vertebral bone marrow fat fraction values within the five Pfirrmann groups, five age groups, and five lumbar levels were statistically analyzed. RESULTS: The vertebral bone marrow fat fraction had a significant negative correlation with T2 values of nucleus pulposus' T2 values (p < 0.001). However, the significant negative correlation was only found between T2 values of nucleus pulposus and adjacent vertebral bone marrow fat in Pfirrmann II-III, L1/2-L5/S1 level, and 40-49 years' age groups. Pfirrmann grades of the intervertebral disc were positively correlated with adjacent vertebrae bone marrow fat fraction (p < 0.05). CONCLUSION: Lumbar bone marrow fat deposition significantly increases during the early stages of intervertebral disc degeneration. Quantitative measurements of bone marrow fat deposition and water content of intervertebral discs have a predictive value and are an important supplement to the qualitative traditional classification strategies for the early stages of intervertebral disc degeneration.

Regulation of Eosinophil Recruitment and Allergic Airway Inflammation by Tropomyosin Receptor Kinase A.

Eosinophilia is a hallmark of allergic airway inflammation (AAI). Identifying key molecules and specific signaling pathways that regulate eosinophilic inflammation is critical for development of novel therapeutics. Tropomycin receptor kinase A (TrkA) is the high-affinity receptor for nerve growth factor. AAI is associated with increased expression of TrkA by eosinophils; however, the functional role of TrkA in regulating eosinophil recruitment and contributing to AAI is poorly understood. This study identifies, to our knowledge, a novel mechanism of eotaxin-mediated activation of TrkA and its role in regulating eosinophil recruitment by using a chemical-genetic approach to specifically inhibit TrkA kinase activity with 1-NM-PP1 in TrkAF592A-knock-in (TrkA-KI) eosinophils. Blockade of TrkA by 1-NM-PP1 enhanced eosinophil spreading on VCAM-1 but inhibited eotaxin-1 (CCL11)-mediated eosinophil migration, calcium flux, cell polarization, and ERK1/2 activation, suggesting that TrkA is an important player in the signaling pathway activated by eotaxin-1 during eosinophil migration. Further, blockade of matrix metalloprotease with BB-94 inhibited eotaxin-1-induced TrkA activation and eosinophil migration, additively with 1-NM-PP1, indicating a role for matrix metalloproteases in TrkA activation. TrkA inhibition in Alternaria alternata-challenged TrkA-KI mice markedly inhibited eosinophilia and attenuated various features of AAI. These findings are indicative of a distinctive eotaxin-mediated TrkA-dependent signaling pathway, which, in addition to other TrkA-activating mediators, contributes to eosinophil recruitment during AAI and suggests that targeting the TrkA signaling pathway to inhibit eosinophil recruitment may serve as a therapeutic strategy for management of eosinophilic inflammation in allergic airway disease, including asthma.

Genome-wide profiling of prognosis-related alternative splicing signatures in sarcoma.

BACKGROUND: Sarcomas (SARCs) are rare malignant tumors with poor prognosis. Increasing evidence has suggested that aberrant alternative splicing (AS) is strongly associated with tumor initiation and progression. We considered whether survival-related AS events might serve as prognosis predictors and underlying targeted molecules in SARC treatment. METHODS: RNA-Seq data of the SARC cohort were downloaded from The Cancer Genome Atlas (TCGA) database. Survival-related AS events were selected by univariate and multivariate Cox regression analyses. Metascape was used for constructing a gene interaction network and performing functional enrichment analysis. Then, prognosis predictors were established based on statistically significant survival-related AS events and evaluated by receiver operator characteristic (ROC) curve analysis. Finally, the potential regulatory network was analyzed via Pearson's correlation between survival-related AS events and splicing factors (SFs). RESULTS: A total of 3,610 AS events and 2,291 genes were found to be prognosis-related in 261 SARC samples. The focal adhesion pathway was identified as the most critical molecular mechanism corresponding to poor prognosis. Notably, several prognosis predictors based on survival-related AS events showed excellent performance in prognosis prediction. The area under the curve of the ROC of the risk score was 0.85 in the integrated predictor. The splicing network proved complicated regulation between prognosis-related SFs and AS events. Also, driver gene mutations were significantly associated with AS in SARC patients. CONCLUSIONS: Survival-related AS events may become ideal indictors for the prognosis prediction of SARCs. Corresponding splicing regulatory mechanisms are worth further exploration.

Biological Characterization of Conserved Residues within the Cytoplasmic Tail of the Pichinde Arenaviral Glycoprotein Subunit 2 (GP2).

Several mammarenaviruses can cause deadly hemorrhagic fever infections in humans, with limited preventative and therapeutic measures available. Arenavirus cell entry is mediated by the viral glycoprotein (GP) complex, which consists of the stable signal peptide (SSP), the receptor-binding subunit GP1, and the transmembrane subunit GP2. The GP2 cytoplasmic tail (CT) is relatively conserved among arenaviruses and is known to interact with the SSP to regulate GP processing and membrane fusion, but its biological role in the context of an infectious virus has not been fully characterized. Using a Pichinde virus (PICV) GP expression vector and a PICV reverse genetics system, we systematically characterized the functional roles of 12 conserved residues within the GP2 CT in GP processing, trafficking, assembly, and fusion, as well as in viral replication. Except for P478A and K505A R508A, alanine substitutions at conserved residues abolished GP processing and membrane fusion in plasmid-transfected cells. Six invariant H and C residues and W503 are essential for viral replication, as evidenced by the fact that their mutant viruses could not be rescued. Both P480A and R482A mutant viruses were rescued, grew similarly to wild-type (WT) virus, and produced evidently processed GP1 and GP2 subunits in virus-infected cells, despite the fact that the same mutations abolished GP processing and membrane fusion in a plasmid-based protein expression system, illustrating the importance of using an infectious-virus system for analyzing viral glycoprotein function. In summary, our results demonstrate an essential biological role of the GP2 CT in arenavirus replication and suggest it as a potential novel target for developing antivirals and/or attenuated viral vaccine candidates.IMPORTANCE Several arenaviruses, such as Lassa virus (LASV), can cause severe and lethal hemorrhagic fever diseases with high mortality and morbidity, for which no FDA-approved vaccines or therapeutics are available. Viral entry is mediated by the arenavirus GP complex, which consists of the stable signal peptide (SSP), the receptor-binding subunit GP1, and the transmembrane subunit GP2. The cytoplasmic tail (CT) of GP2 is highly conserved among arenaviruses, but its functional role in viral replication is not completely understood. Using a reverse genetics system of a prototypic arenavirus, Pichinde virus (PICV), we show that the GP2 CT contains certain conserved residues that are essential for virus replication, implicating it as a potentially good target for developing antivirals and live-attenuated viral vaccines against deadly arenavirus pathogens.