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Differentiation of a human eosinophilic leukemia cell line, EoL-1, in response to treatment with sodium n-butyrate and cytokines associated with the induction of CysLT receptor expression. (A) Ten micro grams of protein from control (lane 1: RPMI1640+ 10%FCS only) and stimulated (lane 2: IL-3, IL-5 and GM-CSF, lane 3: n-butyrate, and lane 4: IL-3, IL-5, GM-CSF and n-butyrate) cells was used for western blot analysis of CysLT1 receptor (CysLT1R) and CysLT2 receptor (CysLT2R) expression
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Numerous reports have shown that cysteinyl leukotrienes (CysLTs) contribute to tissue accumulation of eosinophils in allergic airway inflammation. To date, only a few studies have reported that CysLTs promote chemotactic activity of human eosinophils in vitro. The purpose of this study was to investigate whether CysLTs promote chemotaxis in the hum...
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... Eosinophil migration was measured using the Boyden chamber inserts (5 μm, Corning). Briefly, human eosinophilic leukemia cells EoL-1 [51] were added to the upper chamber whereas the conditioned media collected from hepatocytes were added to the lower chamber. In certain experiments, recombinant murine eotaxin (20 ng/ml, R&D) was directly added to the conditioned media. ...
Infiltration of eosinophils is associated with and contributes to liver regeneration. Chemotaxis of eosinophils is orchestrated by the eotaxin family of chemoattractants. We report here that expression of eotaxin-1 (referred to as eotaxin hereafter), but not that of either eotaxin-2 or eotaxin-3, were elevated, as measured by quantitative PCR and ELISA, in the proliferating murine livers compared to the quiescent livers. Similarly, exposure of primary murine hepatocytes to hepatocyte growth factor (HGF) stimulated eotaxin expression. Liver specific deletion of Brahma-related gene 1 (Brg1), a chromatin remodeling protein, attenuated eosinophil infiltration and down-regulated eotaxin expression in mice. Brg1 deficiency also blocked HGF-induced eotaxin expression in cultured hepatocytes. Further analysis revealed that Brg1 could directly bind to the proximal eotaxin promoter to activate its transcription. Mechanistically, Brg1 interacted with nuclear factor kappa B (NF-κB)/RelA to activate eotaxin transcription. NF-κB knockdown or pharmaceutical inhibition disrupted Brg1 recruitment to the eotaxin promoter and blocked eotaxin induction in hepatocytes. Adenoviral mediated over-expression of eotaxin overcame Brg1 deficiency caused delay in liver regeneration in mice. On the contrary, eotaxin depletion with RNAi or neutralizing antibodies retarded liver regeneration in mice. More important, Brg1 expression was detected to be correlated with eotaxin expression and eosinophil infiltration in human liver specimens. In conclusion, our data unveil a novel role of Brg1 as a regulator of eosinophil trafficking by activating eotaxin transcription.
... In recent years, accumulating evidence has shown that CysLTs, among other mediators (cytokines, chemokines, growth factors, alarmins, and lipid mediators), play essential roles in regulating eosinophil recruitment [37]. Indeed, CysLTs display eosinophilotactic activity in vitro via CysLT1 [86,87]. In vivo, involvement of CysLTs in eosinophil influx was first demonstrated in guinea pigs in the 1990s [88], and then in humans [89]. ...
Leukotrienes (LTs) are lipid mediators that play pivotal roles in acute and chronic inflammation and allergic diseases. They exert their biological effects by binding to specific G-protein-coupled receptors. Each LT receptor subtype exhibits unique functions and expression patterns. LTs play roles in various allergic diseases, including asthma (neutrophilic asthma and aspirin-sensitive asthma), allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and anaphylaxis. This review summarizes the biology of LTs and their receptors, recent developments in the area of anti-LT strategies (in settings such as ongoing clinical studies), and prospects for future therapeutic applications.
... EoL-1 exhibits cytological features of myeloblasts under normal culture conditions. They also spontaneously differentiate phenotypically and functionally into mature eosinophils, as well as by stimulation of agents such as tumour necrosis factor (TNF)-a, butyric acid, dimethylsulfoxide, n-butyrate, interleukin IL3, IL5, and granulocytemacrophage colony-stimulating factor (Mayumi, 1992;Shirasaki et al, 2017). This cell line, unlike other model cell lines, differentiates only to eosinophils and not to other leucocytes. ...
Eosinophils are acidophilic granulocytes that develop in the bone marrow. Although their population contributes only to approximately 1–6% of all leucocytes present in the human blood, they possess a wide range of specific functions. They play a key role in inflammation‐regulating processes, when their numbers can increased to above 5 × 10⁹/l of peripheral blood. Their characteristic feature is the presence of granules containing eosinophil peroxidase (EPO), the release of which can trigger a cascade of events promoting oxidative stress, apoptosis or necrosis, leading finally to cell death. Raman spectroscopy is a powerful technique to detect EPO, which comprises a chromophore protoporphyrin IX. Another cell structure associated with inflammation processes are lipid bodies (lipid‐rich organelles), also well recognized and imaged using high resolution confocal Raman spectroscopy. In this work, eosinophils isolated from the blood of a human donor were analysed versus their model, EoL‐1 human eosinophilic leukaemia cell line, by Raman spectroscopic imaging. We showed that EPO was present only in primary cells and not found in the cell line. Eosinophils were activated using phorbol 12‐myristate 13‐acetate, which resulted in lipid bodies formation. An effect of cells stimulation was studied and compared for eosinophils and EoL‐1.
