Selected ginsenosides of the prptopanaxdiol series are novel positive allosteric modulators of P2X7 receptors

Background and Purpose The P2X7 receptor is an ATP-gated ion channel predominantly expressed in immune cells and plays a key role in inflammatory processes. Ginseng is a well-known Chinese herb with both pro- and anti-inflammatory properties and many of its actions have been ascribed to constituent ginsenosides. We screened a number of ginsenoside compounds for pharmacological activity at P2X7 receptors, that might contribute to the reported immunomodulatory actions of ginseng. Experimental Approach We used several assays to measure responses of P2X7 receptors, ATP-mediated dye uptake, intracellular calcium measurement and whole-cell patch-clamp recordings. HEK-293 cells stably expressing human P2X7 receptors were used in addition to mouse macrophages endogenously expressing P2X7 receptors. Key Results Four ginsenosides of the protopanaxdiol series, Rb1, Rh2, Rd and the metabolite compound K (CK) potentiated the dye uptake responses of P2X7 receptors, whereas other ginsenosides tested were ineffective (1–10 μM). The potentiation was rapid in onset, required a threshold concentration of ATP (>50 μM) and had an EC50 of 1.08 μM. CK markedly enhanced ATP-activated P2X7 currents, probably via an extracellular site of action. One of the consequences of this potentiation effect is a sustained rise in intracellular Ca2+ that could account for the decrease in cell viability in mouse macrophages after a combination of 500 μM ATP and 10 μM CK that are non-toxic when applied alone. Conclusions and Implications This study identifies selected ginsenosides as novel potent allosteric modulators of P2X7 channels that may account for some of the reported immune modulatory actions of protopanaxdiol ginsenosides in vivo

Automatic Storage Optimization of Arrays Affine Loop Nests

Efficient memory usage is crucial for data-intensive applications as a smaller memory footprint ensures better cache performance and allows one to run a larger problem size given a axed amount of main memory. The solutions found by existing techniques for automatic storage optimization for arrays in a new loop-nests, which minimize the storage requirements for the arrays, are often far from good or optimal and could even miss nearly all storage optimization potential. In this work, we present a new automatic storage optimization framework and techniques that can be used to achieve intra-array as well as inter-array storage reuse within a new loop-nests with a pre-determined schedule. Over the last two decades, several heuristics have been developed for achieving complex transformations of a new loop-nests using the polyhedral model. However, there are no comparably strong heuristics for tackling the problem of automatic memory footprint optimization. We tackle the problem of storage optimization for arrays by formulating it as one of ending the right storage partitioning hyperplanes: each storage partition corresponds to a single storage location. Statement-wise storage partitioning hyperplanes are determined that partition a unit end global array space so that values with overlapping live ranges are not mapped to the same partition. Our integrated heuristic for exploiting intra-array as well as inter-array reuse opportunities is driven by a fourfold objective function that not only minimizes the dimensionality and storage requirements of arrays required for each high-level statement, but also maximizes inter-statement storage reuse. We built an automatic polyhedral storage optimizer called SMO using our storage partitioning approach. Storage reduction factors and other results we report from SMO demon-strate the e activeness of our approach on several benchmarks drawn from the domains of image processing, stencil computations, high-performance computing, and the class of tiled codes in general. The reductions in storage requirement over previous approaches range from a constant factor to asymptotic in the loop blocking factor or array extents { the latter being a dramatic improvement for practical purposes. As an incidental and related topic, we also studied the problem of polyhedral compilation of graphical data programs. While polyhedral techniques for program transformation are now used in several proprietary and open source compilers, most of the research on poly-herald compilation has focused on imperative languages such as C, where the computation is species in terms of statements with zero or more nested loops and other control structures around them. Graphical data ow languages, where there is no notion of statements or a schedule specifying their relative execution order, have so far not been studied using a powerful transformation or optimization approach. The execution semantics and ref-eventual transparency of data ow languages impose a di errant set of challenges. In this work, we attempt to bridge this gap by presenting techniques that can be used to extract polyhedral representation from data ow programs and to synthesize them from their equivalent polyhedral representation. We then describe Polyglot, a framework for automatic transformation of data ow programs that we built using our techniques and other popular research tools such as Clan and Pluto. For the purpose of experimental evaluation, we used our tools to compile LabVIEW, one of the most widely used data ow programming languages. Results show that data ow programs transformed using our framework are able to outperform those compiled otherwise by up to a factor of seventeen, with a mean speed-up of 2.30 while running on an 8-core Intel system

Store-Operated Ca2+ Entry (SOCE) and Purinergic Receptor-Mediated Ca2+ Homeostasis in Murine bv2 Microglia Cells: Early Cellular Responses to ATP-Mediated Microglia Activation

Microglia activation is a neuroinflammatory response to parenchymal damage with release of intracellular metabolites, e.g., purines, and signaling molecules from damaged cells. Extracellular purines can elicit Ca(2+)-mediated microglia activation involving P2X/P2Y receptors with metabotropic (P2Y) and ionotropic (P2X) cell signaling in target cells. Such microglia activation results in increased phagocytic activity, activation of their inflammasome and release of cytokines to sustain neuroinflammatory (so-called M1/M2 polarization). ATP-induced activation of ionotropic P2X4 and P2X7 receptors differentially induces receptor-operated Ca(2+) entry (ROCE). Although store-operated Ca(2+) entry (SOCE) was identified to modulate ROCE in primary microglia, its existence and role in one of the most common murine microglia cell line, BV2, is unknown. To dissect SOCE from ROCE in BV2 cells, we applied high-resolution multiphoton Ca(2+) imaging. After depleting internal Ca(2+) stores, SOCE was clearly detectable. High ATP concentrations (1 mM) elicited sustained increases in intracellular [Ca(2+)]i whereas lower concentrations (≤100 μM) also induced Ca(2+) oscillations. These differential responses were assigned to P2X7 and P2X4 activation, respectively. Pharmacologically inhibiting P2Y and P2X responses did not affect SOCE, and in fact, P2Y-responses were barely detectable in BV2 cells. STIM1S content was significantly upregulated by 1 mM ATP. As P2X-mediated Ca(2+) oscillations were rare events in single cells, we implemented a high-content screening approach that allows to record Ca(2+) signal patterns from a large number of individual cells at lower optical resolution. Using automated classifier analysis, several drugs (minocycline, U73122, U73343, wortmannin, LY294002, AZ10606120) were tested on their profile to act on Ca(2+) oscillations (P2X4) and sustained [Ca(2+)]i increases. We demonstrate specific drug effects on purinergic Ca(2+) pathways and provide new pharmacological insights into Ca(2+) oscillations in BV2 cells. For example, minocycline inhibits both P2X7- and P2X4-mediated Ca(2+)-responses, and this may explain its anti-inflammatory action in neuroinflammatory disease. As a technical result, our novel automated bio-screening approach provides a biomedical engineering platform to allow high-content drug library screens to study neuro-inflammation in vitro

Automatic Storage Optimization for Arrays

International audienceEfficient memory allocation is crucial for data-intensive applications as a smaller memory footprint ensures better cache performance and allows one to run a larger problem size given a fixed amount of main memory. In this paper, we describe a new automatic storage optimization technique to minimize the dimensionality and storage requirements of arrays used in sequences of loop nests with a predetermined schedule. We formulate the problem of intra-array storage optimization as one of finding the right storage partitioning hyperplanes: each storage partition corresponds to a single storage location. Our heuristic is driven by a dual objective function that minimizes both, the dimensionality of the mapping and the extents along those dimensions. The technique is dimension optimal for most codes encountered in practice. The storage requirements of the mappings obtained also are asymptotically better than those obtained by any existing schedule-dependent technique. Storage reduction factors and other results we report from an implementation of our technique demonstrate its effectiveness on several real-world examples drawn from the domains of image processing, stencil computations, high-performance computing, and the class of tiled codes in general

Paroxetine suppresses recombinant human P2X7 responses

P2X7 receptor (P2X7) activity may link inflammation to depressive disorders. Genetic variants of human P2X7 have been linked with major depression and bipolar disorders, and the P2X7 knockout mouse has been shown to exhibit anti-depressive-like behaviour. P2X7 is an ATP-gated ion channel and is a major regulator of the pro-inflammatory cytokine interleukin 1β (IL-1β) secretion from monocytes and microglia. We hypothesised that antidepressants may elicit their mood enhancing effects in part via modulating P2X7 activity and reducing inflammatory responses. In this study, we determined whether common psychoactive drugs could affect recombinant and native human P2X7 responses in vitro. Common antidepressants demonstrated opposing effects on human P2X7-mediated responses; paroxetine inhibited while fluoxetine and clomipramine mildly potentiated ATP-induced dye uptake in HEK-293 cells stably expressing recombinant human P2X7. Paroxetine inhibited dye uptake mediated by human P2X7 in a concentration-dependent manner with an IC50 of 24 μM and significantly reduces ATP-induced inward currents. We confirmed that trifluoperazine hydrochloride suppressed human P2X7 responses (IC50 of 6.4 μM). Both paroxetine and trifluoperazine did not inhibit rodent P2X7 responses, and mutation of a known residue (F 95L) did not alter the effect of either drug, suggesting neither drug binds at this site. Finally, we demonstrate that P2X7-induced IL-1β secretion from lipopolysaccharide (LPS)-primed human CD14+ monocytes was suppressed with trifluoperazine and paroxetine

Dietary administration impact of olive pulp on growth performance, metabolic profile, immune status, and antioxidant potential of gilthead seabream (Sparus aurata L.)

The use of natural immunostimulants in aquaculture is intended to foster overall health and bolster resilience against diseases in farmed fish populations. It constitutes a crucial strategy that can contribute to securing the sustainability of the aquaculture industry, and it is an area that warrants ongoing exploration and development. Therefore, the aim of the present work was to evaluate the effect of dietary administration of olive pulp on growth rate, metabolic profile, serum antioxidant potential, and humoral and cellular innate immune parameters of gilthead seabream (Sparus aurata L.). For this, fish were fed control diet or olive pulp enriched diets (50, 100, and 200 mg kg feed−1) for 4 weeks. Our results demonstrated that the highest inclusion level improved the growth rates and the biological antioxidant potential in the serum of fish. However, after 4 weeks of feeding, most of the assayed metabolic parameters (Ca2+, TP, ALB, K+, and Na+) were increased in the serum of fish fed with a diet containing the lowest level of olive pulp (50 mg kg feed−1). Regarding the innate immune parameters, the IgM levels decreased in the serum of fish fed 50′s diet after 2 and 4 weeks of trial. However, the serum of fish fed with diets containing 100 and 200 showed an increase in hemolytic complement activity after 2 weeks whilst this increase was only sustained in the 200′s group after 4 weeks. After 2 weeks of feeding, the serum of the fish showed an increase in peroxidase activity due to the highest olive inclusion. Concerning cellular innate parameters, peroxidase activity, respiratory burst, and phagocytic ability were increased in head-kidney leucocytes of fish fed 100′s diet at 2 weeks compared to values from control fish. These results suggest that the administration of olive pulp-enriched diets can benefit fish growth, antioxidant, and immune status of gilthead seabream

Probenecid Blocks Human P2X7 Receptor-Induced Dye Uptake via a Pannexin-1 Independent Mechanism

P2X7 is a ligand-gated ion channel which is activated by ATP and displays secondary permeability characteristics. The mechanism of development of the secondary permeability pathway is currently unclear, although a role for the hemichannel protein pannexin-1 has been suggested. In this study we investigated the role of pannexin-1 in P2X7-induced dye uptake and ATP-induced IL-1β secretion from human monocytes. We found no pharmacological evidence for involvement of pannexin-1 in P2X7-mediated dye uptake in transfected HEK-293 cells with no inhibition seen for carbenoxolone and the pannexin-1 mimetic inhibitory peptide, 10Panx1. However, we found that probenecid inhibited P2X7-induced cationic and anionic dye uptake in stably transfected human P2X7 HEK-293 cells. An IC50 value of 203 μM was calculated for blockade of ATP-induced responses at human P2X7. Probenecid also reduced dye uptake and IL-1β secretion from human CD14+ monocytes whereas carbenoxolone and 10Panx1 showed no inhibitory effect. Patch clamp and calcium indicator experiments revealed that probenecid directly blocks the human P2X7 receptor

Model-based investigation into atmospheric freeze drying assisted by power ultrasound

Atmospheric freeze drying consists of a convective drying process using air at a temperature below the freezing point of the processed product, and with a very low relative humidity content. This paper focuses on the use of a simple one-dimensional model considering moving boundary vapor diffusion to describe the ultrasonic assisted atmospheric freeze-drying of foodstuffs. The case study is the drying of apple cubes (8.8 mm) at different air velocities (1, 2, 4 and 6 m/s), temperatures ( 5, 10 and 15 C), without and with (25, 50 and 75 W) power ultrasound application. By fitting the proposed diffusion model to the experimental drying kinetics, the effective diffusivity of water vapor in the dried product was estimated. The model was successfully validated by drying apple samples of different size and geometry (cubes and cylinders). Finally, a 23 factorial design of experiments revealed that the most relevant operating parameter affecting the drying time was the applied ultrasound power level.The authors acknowledge the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO) and of the European Regional Development Fund (ERDF) through the project DPI2012-37466-CO3-03, the FPI fellowship (BES-2010-033460) and the EEBB-I-14-08572 fellowship granted to J.V. Santacatalina for a short stay at Politecnico di Torino.Santacatalina Bonet, JV.; Fissore, D.; Cárcel Carrión, JA.; Mulet Pons, A.; García Pérez, JV. (2015). Model-based investigation into atmospheric freeze drying assisted by power ultrasound. Journal of Food Engineering. 151:7-15. https://doi.org/10.1016/j.jfoodeng.2014.11.013S71515