Mechanisms for Vascular Cell Adhesion Molecule-1 Activation of ERK1/2 during Leukocyte Transendothelial Migration

Background: During inflammation, adhesion molecules regulate recruitment of leukocytes to inflamed tissues. It is reported that vascular cell adhesion molecule-1 (VCAM-1) activates extracellular regulated kinases 1 and 2 (ERK1/2), but the mechanism for this activation is not known. Pharmacological inhibitors of ERK1/2 partially inhibit leukocyte transendothelial migration in a multi-receptor system but it is not known whether VCAM-1 activation of ERK1/2 is required for leukocyte transendothelial migration (TEM) on VCAM-1. Methodology/Principal Findings: In this study, we identified a mechanism for VCAM-1 activation of ERK1/2 in human and mouse endothelial cells. VCAM-1 signaling, which occurs through endothelial cell NADPH oxidase, protein kinase Ca (PKCa), and protein tyrosine phosphatase 1B (PTP1B), activates endothelial cell ERK1/2. Inhibition of these signals blocked VCAM-1 activation of ERK1/2, indicating that ERK1/2 is activated downstream of PTP1B during VCAM-1 signaling. Furthermore, VCAM-1-specific leukocyte migration under physiological laminar flow of 2 dynes/cm 2 was blocked by pretreatment of endothelial cells with dominant-negative ERK2 K52R or the MEK/ERK inhibitors, PD98059 and U0126, indicating for the first time that ERK regulates VCAM-1-dependent leukocyte transendothelial migration. Conclusions/Significance: VCAM-1 activation of endothelial cell NADPH oxidase/PKCa/PTP1B induces transient ERK1/2 activation that is necessary for VCAM-1-dependent leukocyte TEM

Association of citrulline concentration at birth with lower respiratory tract infection in infancy: Findings from a multi-site birth cohort study

Assessing the association of the newborn metabolic state with severity of subsequent respiratory tract infection may provide important insights on infection pathogenesis. In this multi-site birth cohort study, we identified newborn metabolites associated with lower respiratory tract infection (LRTI) in the first year of life in a discovery cohort and assessed for replication in two independent cohorts. Increased citrulline concentration was associated with decreased odds of LRTI (discovery cohort: aOR 0.83 [95% CI 0.70-0.99], p = 0.04; replication cohorts: aOR 0.58 [95% CI 0.28-1.22], p = 0.15). While our findings require further replication and investigation of mechanisms of action, they identify a novel target for LRTI prevention and treatment

Nonclassical Ly6C(-) Monocytes Drive the Development of Inflammatory Arthritis in Mice

Different subsets and/or polarized phenotypes of monocytes and macrophages may play distinct roles during the development and resolution of inflammation. Here, we demonstrate in a murine model of rheumatoid arthritis that non-classical Ly6C(−) monocytes are required for the initiation and progression of sterile joint inflammation. Moreover, non-classical Ly6C(−) monocytes differentiate into inflammatory macrophages (M1), which drive disease pathogenesis and display plasticity during the resolution phase. During the development of arthritis, these cells polarize toward an alternatively activated phenotype (M2), promoting the resolution of joint inflammation. The influx of Ly6C(−) monocytes and their subsequent classical and then alternative activation occurs without changes in synovial tissue-resident macrophages, which express markers of M2 polarization throughout the course of the arthritis and attenuate joint inflammation during the initiation phase. These data suggest that circulating Ly6C(−) monocytes recruited to the joint upon injury orchestrate the development and resolution of autoimmune joint inflammation

Peculiarities of the Translation of Fantasy Genre: A. Sapkowski's "The Witcher: The Last Wish".

Fantāzijas literatūras tulkošanas īpatnības: A. Sapkovska “Pēdējā vēlēšanās”: bakalaura darbs. – Rīga, 2018. – 47 lpp. Bakalaura darbs tiek veltīts fantāzijas literatūras tulkošanas īpatnību izpētei, par piemēru ņemot Andžeja Sapkovska romānu “Pēdējā vēlēšanās”. Pētījuma mērķis ir atklāt un raksturot fantāzijas žanra literatūras tulkošanas īpatnības. Autors noskaidro daiļdarba tulkošanas procesa īpatnības un salīdzina romāna tekstu oriģinālvalodā un krievu tulkojumā. Liela uzmanība tiek pievērsta bezekvivalenta leksikai, galvenokārt personvārdiem, kas ir raksturīga dotajam literatūras žanram. Darbs sastāv no divām nodaļām. Pirmā nodaļa sniedz pārskatu par šā pētījuma svarīgākajiem teorētiskajiem jautājumiem. Otrā nodaļa ir veltīta romāna oriģinālvalodas un krievu tulkojuma teksta salīdzināšanai un analīzei. Darbs var ieinteresēt filologus, kas nodarbojas ar līdzīgu problemātiku, kā arī citus interesentus.Peculiarities of the Translation of Fantasy Genre: A. Sapkowski's "The Witcher: The Last Wish": bachelor’s thesis. – Riga, 2018. – 47 p. The thesis focuses on fantasy translation’s features based on example of A. Sapkowski’s “The Witcher: The Last Wish”. The goal of this research is to determine the peculiarities of the translation of fantasy genre. The paper’s author compiles features of a literature translation, compares original novel’s text with its translated version and determines fantasy translation features. Lexical units that don’t have an equivalent counterpart in language which the text is translated to require a special attention in this research. The emphasis was laid upon the examination of proper nouns. This thesis is divided into two parts. The first part examines the theoretical part of the question. The second part is focused on translation analysis and further determination of the fantasy literature translation’s peculiarities. This thesis may be of interest to philologists researching literature translation

Endocrine Disruptor Bisphenol A (BPA) Triggers Systemic Para-Inflammation and is Sufficient to Induce Airway Allergic Sensitization in Mice

Allergic airway diseases are accompanied by increased permeability and an inflammatory state of epithelial barriers, which are thought to be susceptible to allergen sensitization. Although exogenous drivers (proteases, allergens) of epithelial barrier disruption and sensitization are well studied, endogenous contributors (diet, xenobiotics, hormones, and metabolism) to allergic sensitization are much less understood. Xenoestrogens are synthetic or natural chemical compounds that have the ability to mimic estrogen and are ubiquitous in the food and water supply of developed countries. By interfering with the estrogen produced by the endocrine system, these compounds have the systemic potential to disrupt the homeostasis of multiple tissues. Our study examined the potential of prototypical xenoestrogen bisphenol A (BPA) to disrupt epithelial homeostasis in vitro and promote allergic responses in vivo. We found that BPA exposure in epithelial cultures in vitro significantly inhibited epithelial cell proliferation and wound healing, as well as promoted the expression of the innate alarmin cytokine TSLP in a time-and dose-dependent manner. In vivo, the exposure to BPA through water supply or inhalation induced a systemic para-inflammatory response by promoting the expression of innate inflammatory mediators in the skin, gut, and airway. In a murine tolerogenic antigen challenge model, chronic systemic exposure to BPA was sufficient to induce airway sensitization to innocuous chicken egg ovalbumin in the complete absence of adjuvants. Mechanistic studies are needed to test conclusively whether endocrine disruptors may play an upstream role in allergic sensitization via their ability to promote a para-inflammatory state

Vitamin E isoforms differentially regulate intercellular adhesion molecule-1 activation of PKCα in human microvascular endothelial cells.

ICAM-1-dependent leukocyte recruitment in vivo is inhibited by the vitamin E isoform d-α-tocopherol and elevated by d-γ-tocopherol. ICAM-1 is reported to activate endothelial cell signals including protein kinase C (PKC), but the PKC isoform and the mechanism for ICAM-1 activation of PKC are not known. It is also not known whether ICAM-1 signaling in endothelial cells is regulated by tocopherol isoforms. We hypothesized that d-α-tocopherol and d-γ-tocopherol differentially regulate ICAM-1 activation of endothelial cell PKC.ICAM-1 crosslinking activated the PKC isoform PKCα but not PKCβ in TNFα-pretreated human microvascular endothelial cells. ICAM-1 activation of PKCα was blocked by the PLC inhibitor U73122, ERK1/2 inhibitor PD98059, and xanthine oxidase inhibitor allopurinol. ERK1/2 activation was blocked by inhibition of XO and PLC but not by inhibition of PKCα, indicating that ERK1/2 is downstream of XO and upstream of PKCα during ICAM-1 signaling. During ICAM-1 activation of PKCα, the XO-generated ROS did not oxidize PKCα. Interestingly, d-α-tocopherol inhibited ICAM-1 activation of PKCα but not the upstream signal ERK1/2. The d-α-tocopherol inhibition of PKCα was ablated by the addition of d-γ-tocopherol.Crosslinking ICAM-1 stimulated XO/ROS which activated ERK1/2 that then activated PKCα. ICAM-1 activation of PKCα was inhibited by d-α-tocopherol and this inhibition was ablated by the addition of d-γ-tocopherol. These tocopherols regulated ICAM-1 activation of PKCα without altering the upstream signal ERK1/2. Thus, we identified a mechanism for ICAM-1 activation of PKC and determined that d-α-tocopherol and d-γ-tocopherol have opposing regulatory functions for ICAM-1-activated PKCα in endothelial cells

Vitamin E Isoforms as Modulators of Lung Inflammation

Asthma and allergic diseases are complex conditions caused by a combination of genetic and environmental factors. Clinical studies suggest a number of protective dietary factors for asthma, including vitamin E. However, studies of vitamin E in allergy commonly result in seemingly conflicting outcomes. Recent work indicates that allergic inflammation is inhibited by supplementation with the purified natural vitamin E isoform α-tocopherol but elevated by the isoform γ-tocopherol when administered at physiological tissue concentrations. In this review, we discuss opposing regulatory effects of α-tocopherol and γ-tocopherol on allergic lung inflammation in clinical trials and in animal studies. A better understanding of the differential regulation of inflammation by isoforms of vitamin E provides a basis towards the design of clinical studies and diets that would effectively modulate inflammatory pathways in lung disease

Comparative Study of SARS-CoV-2, SARS-CoV-1, MERS-CoV, HCoV-229E and Influenza Host Gene Expression in Asthma: Importance of Sex, Disease Severity, and Epithelial Heterogeneity

Epithelial characteristics underlying the differential susceptibility of chronic asthma to SARS-CoV-2 (COVID-19) and other viral infections are currently unclear. By revisiting transcriptomic data from patients with Th2 low versus Th2 high asthma, as well as mild, moderate, and severe asthmatics, we characterized the changes in expression of human coronavirus and influenza viral entry genes relative to sex, airway location, and disease endotype. We found sexual dimorphism in the expression of SARS-CoV-2-related genes ACE2, TMPRSS2, TMPRSS4, and SLC6A19. ACE2 receptor downregulation occurred specifically in females in Th2 high asthma, while proteases broadly assisting coronavirus and influenza viral entry, TMPRSS2, and TMPRSS4, were highly upregulated in both sexes. Overall, changes in SARS-CoV-2-related gene expression were specific to the Th2 high molecular endotype of asthma and different by asthma severity and airway location. The downregulation of ACE2 (COVID-19, SARS) and ANPEP (HCoV-229E) viral receptors wascorrelated with loss of club and ciliated cells in Th2 high asthma. Meanwhile, the increase in DPP4 (MERS-CoV), ST3GAL4, and ST6GAL1 (influenza) was associated with increased goblet and basal activated cells. Overall, this study elucidates sex, airway location, disease endotype, and changes in epithelial heterogeneity as potential factors underlying asthmatic susceptibility, or lack thereof, to SARS-CoV-2

Mechanisms for VCAM-1 activation of ERK1/2 in endothelial cell lines.

<p>Monolayers of mHEVa cells were nontreated (NT) or incubated for 30 minutes with apocynin (4 mM), PD98059 (30uM), U0126 (40 µM), Gö-6976 (2.3 nM), CinnGEL 2-methylester (10 µM), or catalase (5000 U/ml) where indicated. These are the optimal doses for these inhibitors as we have previously described <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026706#pone.0026706-Matheny1" target="_blank">[5]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026706#pone.0026706-Deem1" target="_blank">[7]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0026706#pone.0026706-AbdalaValencia1" target="_blank">[8]</a>. At these concentrations, none of the inhibitors had any significant effects on the basal level of ERK1/2 in the absence of anti-VCAM-1 stimulation (data not shown). After treatement with the inhibitor, the endothelial cells were stimulated with anti-VCAM-1 antibody plus a secondary antibody to crosslink VCAM-1 for 30 min under static conditions. We examined phosphorylation of <b>A,B,F</b>) ERK1/2 Thr202/Tyr204 (P-ERK1/2), <b>C</b>) PKCα Thr638 (P-PKCα), or <b>D</b>) MEK1/2 Ser217/221 (P-MEK1/2) by western blot. <b>E</b>) mHEVa cells were treated with exogenous 1 µM H₂O₂ for 10–60 minutes and ERK1/2 Ser217/221 phosphorylation was determined by western blot. The phosphorylation status of ERK1/2 Thr202/Tyr204, PKCα Thr638, or MEK1/2 Ser217/221 is presented as the fold increase in the ratio of the relative intensity of the phosphorylated enzyme to total ERK1/2, total PKCα or total MEK1/2 expression. Representative western blots are shown and data are presented as the mean ± standard deviation from 3 experiments. (<b>A</b>, <b>B</b>) *, p<0.05 less than anti-VCAM-1-treated group. (<b>C–F</b>) *, p<0.05 greater than NT.</p

Tocopherol treatment of TNFα-stimulated HMVECLs was not cytotoxic and did not alter ICAM-1 expression.

<p>70% confluent monolayers of HMVECLs were pretreated for 6 hrs with TNFα (10 ng/ml) to induce ICAM-1 expression. Then, the endothelial cells were treated for 16 hrs with α-tocopherol (α-toc) (40, 60 or 80 µM), γ-tocopherol (γ-toc) (1, 2 or 4 µM) or the vehicle control DMSO (0.01%). The cells were examined for cytotoxicity with the <b>A</b>) Vybrant Cytotoxicity Assay or examined by <b>B,C</b>) immunolabeling with FITC-labeled anti-ICAM-1 and flow cytometry. Shown are the means ± SEM from 3 experiments. MFI, mean fluorescence intensity. *, p<0.05 compared with non-treated (NT) cells.</p