Background Many patients with severe asthma require regular treatment with oral glucocorticoids despite the use of high-dose inhaled therapy. However, the regular use of systemic glucocorticoids can result in serious and often irreversible adverse effects. Mepolizumab, a humanized monoclonal antibody that binds to and inactivates interleukin-5, has been shown to reduce asthma exacerbations in patients with severe eosinophilic asthma. Methods In a randomized, double-blind trial involving 135 patients with severe eosinophilic asthma, we compared the glucocorticoid-sparing effect of mepolizumab (at a dose of 100 mg) with that of placebo administered subcutaneously every 4 weeks for 20 weeks. The primary outcome was the degree of reduction in the glucocorticoid dose (90 to 100% reduction, 75 to less than 90% reduction, 50 to less than 75% reduction, more than 0 to less than 50% reduction, or no decrease in oral glucocorticoid dose, a lack of asthma control during weeks 20 to 24, or withdrawal from treatment)....

Oral Glucocorticoid-Sparing Effect of Mepolizumab in Eosinophilic Asthma

Innate production of T[H]2 cytokines by adipose tissue-associated c-Kit[+]Sca-1[+] lymphoid cells

Exosomes have emerged as a novel mode of intercellular communication. Exosomes can shuttle bioactive molecules including proteins, DNA, mRNA, as well as non-coding RNAs from one cell to another, leading to the exchange of genetic information and reprogramming of the recipient cells. Increasing evidence suggests that tumor cells release excessive amount of exosomes, which may influence tumor initiation, growth, progression, metastasis, and drug resistance. In addition, exosomes transfer message from tumor cells to immune cells and stromal cells, contributing to the escape from immune surveillance and the formation of tumor niche. In this review, we highlight the recent advances in the biology of exosomes as cancer communicasomes. We review the multifaceted roles of exosomes, the small secreted particles, in communicating with other cells within tumor microenvironment. Given that exosomes are cell type specific, stable, and accessible from body fluids, exosomes may provide promising biomarkers for cancer diagnosis and represent new targets for cancer therapy.

/pdf/exosomes-in-cancer-small-particle-big-player-1nt0l03b3f.pdf

Exosomes in cancer: small particle, big player

The authors review the current data on the presence and reported biological effects in fish of some of the most commonly detected pharmaceuticals in the aquatic environment; namely nonsteroidal anti-inflammatory drugs (NSAIDs), fibrates, β-blockers, selective serotonin reuptake inhibitors (SSRIs), azoles, and antibioticsReported biological effects in fish in the laboratory have often been shown to be in accordance with known effects of pharmaceuticals in mammalsWater concentrations at which such effects have been reported, however, are generally, between μg L −1 and mg L −1 , typically at least 1 order of magnitude higher than concentrations normally found in surface waters (ng L −1 )� There are exceptions to this, however, as for the case of synthetic oestrogens, which can induce biological effects in the low ng L −1 rangeAlthough generally effect levels for pharmaceuticals are higher than those found in the environment, the risks to wild fish populations have not been thoroughly characterised, and there has been a lack of consideration given to the likely chronic nature of the exposures, or the potential for mixture effectsAs global consumption of pharmaceuticals rises, an inevitable consequence is an increased level of contamination of surface and ground waters with these biologically active drugs, and thus in turn a greater potential for adverse effects in aquatic wildlife �

Pharmaceuticals in the aquatic environment: a critical review of the evidence for health effects in fish.

Bruton's tyrosine kinase (BTK) is a key component of B cell receptor (BCR) signalling and functions as an important regulator of cell proliferation and cell survival in various B cell malignancies. Small-molecule inhibitors of BTK have shown antitumour activity in animal models and, recently, in clinical studies. High response rates were reported in patients with chronic lymphocytic leukaemia and mantle cell lymphoma. Remarkably, BTK inhibitors have molecular effects that cannot be explained by the classic role of BTK in BCR signalling. In this Review, we highlight the importance of BTK in various signalling pathways in the context of its therapeutic inhibition.

/pdf/targeting-bruton-s-tyrosine-kinase-in-b-cell-malignancies-mf0ddw583x.pdf

Targeting Bruton's tyrosine kinase in B cell malignancies

Background Allergic asthma is a chronic disease of the conducting airways characterized by T H 2 inflammation and tissue remodeling after exposure to inhaled allergens. Although the T H 2 profile is undisputed, the underlying molecular mechanisms leading to this abnormal T H 2 profile remain largely unclear. MicroRNAs (miRNAs) are short noncoding RNAs that are important regulators of gene expression in the immune system. However, the role of miRNAs, specifically miR-155, in the regulation of allergic airway inflammation is unexplored. Objectives We sought to assess the contribution of miR-155 in a mouse model of allergic airway inflammation. Methods To investigate a role for miR-155 in the regulation of allergic inflammation in vivo , we used miR-155 knockout (KO) and wild-type (WT) mice sensitized and exposed to ovalbumin. Results miR-155 deficiency resulted in diminished eosinophilic inflammation and mucus hypersecretion in the lungs of allergen-sensitized and allergen-challenged mice compared with WT control animals. This was supported by a reduction in T H 2 cell numbers and airway T H 2 cytokine levels and complete abrogation of allergen-induced airway eotaxin-2/CCL24 and periostin levels in miR-155 KO mice. Intranasal instillation of eotaxin-2/CCL24 before allergen challenge partially restored airway eosinophilia in miR-155 KO mice, and adoptive transfer of CD4 + T cells resulted in a similar degree of airway eosinophilia in miR-155 KO and WT mice. Furthermore, the transcription factor PU.1, a negative regulator of T H 2 cytokine production, was upregulated in the airways of allergen-challenged miR-155 KO mice compared with WT mice. Conclusions Our data provides evidence that miR-155 contributes to the regulation of allergic airway inflammation by modulating T H 2 responses through the transcription factor PU.1.

https://www.jacionline.org/article/S0091-6749(13)01766-1/pdf

MicroRNA-155 is essential for T(H)2-mediated allergen-induced eosinophilic inflammation in the lung.

The multiple roles of phosphoinositide 3-kinase in mast cell biology

The use of N-substituted imidazoles is widespread, and imidazole and triazole fungicides have been detected in the aquatic environment and shown to bioaccumulate in fish. We have investigated effects of the model imidazole, ketoconazole, on drug-metabolizing cytochrome P450 (CYP) forms. We focused on cytochrome P4501A (CYP1A) and cytochrome P4503A (CYP3A) expression and activities in juvenile rainbow trout and in adult killifish. The CYP1A expression (mRNA, protein) and activity was induced in rainbow trout, whereas in killifish no effect of ketoconazole on CYP1A protein expression was observed. A biphasic dose-response relationship was observed between ketoconazole exposure and hepatic CYP1A-mediated ethoxyresorufin O-deethy-lase (EROD) activity in rainbow trout in vitro and in vivo, implying that higher doses of ketoconazole inhibit CYP1A activities. Slight induction of CYP3A protein levels was observed in rainbow trout exposed in vivo to ketoconazole. However, the CYP3A-mediated benzyloxy-4-[trifluoromethyl]-coumarin (BFC) O-debenzyloxylase activity was reduced in rainbow trout and killifish treated with ketoconazole. In vitro inhibition studies confirmed that ketoconazole was a potent inhibitor of both CYP3A and CYP1A enzyme activities in these species. This study showed that ketoconazole induced CYP1A and CYP3A expression in rainbow trout. However, the most pronounced effect of ketoconazole was a 60 to 90% decrease in CYP3A catalytic activities in rainbow trout and in killifish.

Effects of the antifungal imidazole ketoconazole on CYP1A and CYP3A in rainbow trout and killifish.

Mediators released from activated mast cells are responsible for the allergic inflammatory reactions associated with disease states such as anaphylaxis and atopy. These mediators are released as a consequence of immediate degranulation and phospholipid metabolism, upon mast cell activation, followed by delayed cytokine gene expression. Thus, techniques that monitor indices of these events in mast cell culture systems, in association with biochemical analysis of parameters of cell signaling, are critical to our understanding of the molecular mechanisms regulating mast cell-mediated disease. Furthermore, these systems can be adapted for high throughput screens to identify potential inhibitors of mast cell activation which may provide potential leads for novel therapies for these diseases. In this unit, we describe approaches which can be readily used or adapted for a variety of rodent and human mast cell culture systems for the determination of degranulation, phospholipid-derived inflammatory mediator production, and cytokine generation.

/pdf/measuring-mast-cell-mediator-release-12a3wpi1w2.pdf

Measuring Mast Cell Mediator Release

Background: Human cells release nano-sized vesicles called exosomes, containing mRNA, miRNA and specific proteins. Exosomes from one cell can be taken up by another cell, which is a recently discovered cell-to-cell communication mechanism. Also, exosomes can be taken up by different types of cancer cells, but the potential functional effects of mast cell exosomes on tumor cells remain unknown. Methods and results: Exosomes were isolated from the human mast cell line, HMC-1, and uptake of PKH67-labelled exosomes by the lung epithelial cell line, A549, was examined using flow cytometry and fluorescence microscopy. The RNA cargo of the exosomes was analyzed with a Bioanalyzer and absence or presence of the c-KIT mRNA was determined by RT-PCR. The cell proliferation was determined in a BrdU incorporation assay, and proteins in the KIT-SCF signaling pathway were detected by Western blot. Our result demonstrates that exosomes from mast cells can be taken up by lung cancer cells. Furthermore, HMC-1 exosomes contain and transfer KIT protein, but not the c-KIT mRNA to A549 cells and subsequently activate KIT-SCF signal transduction, which increase cyclin D1 expression and accelerate the proliferatio ni n the human lung adenocarcinoma cells. Conclusions: Our results indicate that exosomes can transfer KIT as a protein to tumor cells, which can affect recipient cell signaling events through receptor-ligand interactions.

/pdf/mast-cell-exosomes-promote-lung-adenocarcinoma-cell-3lnnzfl923.pdf

Madeleine Rådinger

Papers

MicroRNA-155 is essential for T(H)2-mediated allergen-induced eosinophilic inflammation in the lung.

The multiple roles of phosphoinositide 3-kinase in mast cell biology

Effects of the antifungal imidazole ketoconazole on CYP1A and CYP3A in rainbow trout and killifish.

Measuring Mast Cell Mediator Release

Mast cell exosomes promote lung adenocarcinoma cell proliferation – role of KIT-stem cell factor signaling