Antigen and Thapsigargin Promote Influx of Ca2+ in Rat Basophilic RBL-2H3 Cells by Ostensibly Similar Mechanisms That Allow Filling of Inositol 1,4,5-Trisphosphate-Sensitive and Mitochondrial Ca2+ Stores

In single, Fura 2-loaded RBL-2H3 cells, antigen and thapsigargin depleted the same intracellular pool of Ca2+ in the absence of external Ca2+; provision of external Ca2+ induced immediate increases in levels of free Ca2+ ([Ca2+](i)). These increases were dependent on the presence of external Ca2+ and, presumably, on influx of Ca2+ across the cell membrane. Both stimulants enhanced intracellular accumulation of 45Ca2+ through ostensibly similar mechanisms because accumulation was blocked to similar extents by various multivalent cations or by depolarization with K+. Because thapsigargin blocked reuptake of Ca2+ into inositol 1,4,5-trisphosphate sensitive stores, uptake occurred independently of the refilling of these stores. Uptake was dependent instead on sequestration of 45Ca2+ in a pool of high capacity that was insensitive to thapsigargin, caffeine, GTP and inositol 1,4,5-trisphosphate but sensitive to ionomycin and mitochondrial inhibitors. The existence of an inositol 1,4,5-trisphosphate-insensitive pool was also apparent in permeabilized cells; at 0.1 μM [Ca2+](i), uptake of 45Ca2+ was largely confined (\u3e 80%) to the inositol 1,4,5-trisphosphate-sensitive pool, but at 2 μM [Ca2+](i) uptake was largely (\u3e 60%) into the inositol 1,4,5-trisphosphate-insensitive pool. Provision of mitochondrial inhibitors along with thapsigargin to block uptake into both pools, did not impair the thapsigargin-induced increase in [Ca2+](i) or influx of Ca2+, as indicated by changes in Fura 2 fluorescence, but did block the intracellular accumulation of 45Ca2+. The studies illustrate the utility of simultaneous measurements of [Ca2+](i) and 45Ca2+ uptake for a full accounting of Ca2+ homoeostasis as exemplified by the ability to distinguish between influx and mitochondrial uptake of Ca2+

Plasma beta dependence of turbulent transport suggesting an advantage of weak magnetic shear from local and global gyrokinetic simulations

A higher plasma β is desirable for realizing high performance fusion reactor, in fact, one of the three goals of JT-60SA project is to achieve a high-β regime. We investigate key physical processes that regulate the β dependence of turbulent transport in L-mode plasmas by means of both local and global gyrokinetic simulations. From local simulations, we found that the turbulent transport does not decrease as β increases, because the electromagnetic stabilizing effect is canceled out by the increase of the Shafranov shift. This influence of the Shafranov shift is suppressed when the magnetic shear is weak, and thus the electromagnetic stabilization is prominent in weak shear plasmas, suggesting an advantage of weak magnetic shear plasmas for achieving a high-β regime. In high β regime, local gyrokinetic simulations are suffered from the non-saturation of turbulence level. In global simulations, by contrast, the electromagnetic turbulence gets saturated by the entropy advection in the radial direction to avoid the zonal flow erosion due to magnetic fluctuations. This breakthrough enables us to explore turbulent transport at a higher β regime by gyrokinetic simulations

Effects of Flavonoids Isolated From Orange Jasmine (Murraya Paniculata [L.] Jack.) on Histamine Release From Mast Cells

Murraya paniculata [L.] Jack. (Kemuning) is a plant that grows widely in some areas of Indonesia. Studies related to this plant have been widely explored especially isolation of its active compounds. The plant contents several active compounds such as flanovoids. In the study, three flavonoid isolated from M. paniculata were evaluated for their effect on histamine release from mast cells (RBL-2H3 cells). These compounds were 3,3',4',5,5',6,7,8-octamethoxyflavone; 3,3',4',5,5',6,7-heptamethoxyflavone and 3, 3', 4', 5, 5', 7–hexamethoxyflavone. The histamine inducers used in the study were DNP24-BSA dan thapsigargin, inducing the histamine release immunologically and non-immunologically, respectively. In the study, heptamethoxyflavone and hexamethoxyflavone did not influence the histamine release from mast cells significantly. However, octamethoxyflavone could increase the histamine release from RBL-2H3 cells in absence and presence the histamine inducers. The flavanoid could increase the release of histamine up to 50 %. Based on the results, polymethoxy moieties at the structure of flavonoid have a significant role to emerge the histamine-release stimulating effect from mast cells

On the triad transfer analysis of plasma turbulence : symmetrization, coarse graining, and directional representation

This article discusses triad transfer analysis via quadratic nonlinearity. To avoid fictitious interactions, symmetrization of the triad transfer is reviewed, including arbitrary orthogonal decomposition and coarse graining. The directional representation of the symmetrized triad transfer is proposed by minimizing the number of edges in a network graph of triad interactions with keeping the energy consistency. The directional representation simplifies visualization and allows us to reduce the energy transfer into a one-to-one relation, while eliminating fictitious interactions in non-symmetrized triad transfer functions. Energy transfer processes among plasma turbulent fluctuations that decompose by the singular value decomposition are analyzed as an application. A network graph visualization clearly demonstrates the importance of symmetrization and the consistency between the symmetrized triad transfer and its directional representation

Antihistamines suppress upregulation of histidine decarboxylase gene expression with potencies different from their binding affinities for histamine H1 receptor in toluene 2,4-diisocyanate-sensitized rats

Antihistamines inhibit histamine signaling by blocking histamine H1 receptor (H1R) or suppressing H1R signaling as inverse agonists. The H1R gene is upregulated in patients with pollinosis, and its expression level is correlated with the severity of nasal symptoms. Here, we show that antihistamine suppressed upregulation of histidine decarboxylase (HDC) mRNA expression in patients with pollinosis, and its expression level was correlated with that of H1R mRNA. Certain antihistamines, including mepyramine and diphenhydramine, suppress toluene-2,4-diisocyanate (TDI)-induced upregulation of HDC gene expression and increase HDC activity in TDI-sensitized rats. However, d-chlorpheniramine did not demonstrate any effect. The potencies of antihistamine suppressive effects on HDC mRNA elevation were different from their H1R receptor binding affinities. In TDI-sensitized rats, the potencies of antihistamine inhibitory effects on sneezing in the early phase were related to H1R binding. In contrast, the potencies of their inhibitory effects on sneezing in the late phase were correlated with those of suppressive effects on HDC mRNA elevation. Data suggest that in addition to the antihistaminic and inverse agonistic activities, certain antihistamines possess additional properties unrelated to receptor binding and alleviate nasal symptoms in the late phase by inhibiting synthesis and release of histamine by suppressing HDC gene transcription

TGF-beta 1 induces human alveolar epithelial to mesenchymal cell transition (EMT)

Background: Fibroblastic foci are characteristic features in lung parenchyma of patients with idiopathic pulmonary fibrosis (IPF). They comprise aggregates of mesenchymal cells which underlie sites of unresolved epithelial injury and are associated with progression of fibrosis. However, the cellular origins of these mesenchymal phenotypes remain unclear. We examined whether the potent fibrogenic cytokine TGF-β1 could induce epithelial mesenchymal transition (EMT) in the human alveolar epithelial cell line, A549, and investigated the signaling pathway of TGF-β1-mediated EMT. Methods: A549 cells were examined for evidence of EMT after treatment with TGF-β1. EMT was assessed by: morphology under phase-contrast microscopy; Western analysis of cell lysates for expression of mesenchymal phenotypic markers including fibronectin EDA (Fn-EDA), and expression of epithelial phenotypic markers including E-cadherin (E-cad). Markers of fibrogenesis, including collagens and connective tissue growth factor (CTGF) were also evaluated by measuring mRNA level using RT-PCR, and protein by immunofluorescence or Western blotting. Signaling pathways for EMT were characterized by Western analysis of cell lysates using monoclonal antibodies to detect phosphorylated Erk1/2 and Smad2 after TGF-β1 treatment in the presence or absence of MEK inhibitors. The role of Smad2 in TGF-β1-mediated EMT was investigated using siRNA. Results: The data showed that TGF-β1, but not TNF-α or IL-1β, induced A549 cells with an alveolar epithelial type II cell phenotype to undergo EMT in a time-and concentration-dependent manner. The process of EMT was accompanied by morphological alteration and expression of the fibroblast phenotypic markers Fn-EDA and vimentin, concomitant with a downregulation of the epithelial phenotype marker E-cad. Furthermore, cells that had undergone EMT showed enhanced expression of markers of fibrogenesis including collagens type I and III and CTGF. MMP-2 expression was also evidenced. TGF-β1-induced EMT occurred through phosphorylation of Smad2 and was inhibited by Smad2 gene silencing; MEK inhibitors failed to attenuate either EMT-associated Smad2 phosphorylation or the observed phenotypic changes. Conclusion: Our study shows that TGF-β1 induces A549 alveolar epithelial cells to undergo EMT via Smad2 activation. Our data support the concept of EMT in lung epithelial cells, and suggest the need for further studies to investigate the phenomenon