Tratamento de sementes armazenadas com pós inertes à base de terra de diatomáceas.

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Pós inertes no controle das principais pragas de grãos armazenados.

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Eficácia de Spinosad e IGR Plus no controle das pragas de grãos armazenados Rhyzopertha dominica e Sitophilus zeamais.

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P2X7 Receptor Primes IL-1β and the NLRP3 Inflammasome in Astrocytes Subjected to Mechanical Strain

Inflammatory responses play a key role in many neural pathologies, with localized signaling from non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. Stimulation of the NLRP3 inflammasome is a two-stage process. The priming stage involves upregulation of the biosynthesis of the structural components while activation results in their assembly into the actual inflammasome complex and subsequent activation. The priming step can be rate limiting and can connect insult to chronic inflammation but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammatory conditions is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure (IOP) increased mRNA for inflammasome components IL-1β, NLRP3, ASC, CASP1 and IL-6 in rat and mouse retinas. The P2X7 receptor was implicated in the in vivo mechanosensitive priming of IL-1β and IL-6 transcription and translation. In vitro experiments with optic nerve head astrocytes demonstrated enhanced expression of the IL-1β and IL-6 genes following stretching or swelling. The increase in IL-1β expression was inhibited by degradation of extracellular ATP with apyrase, blocking pannexin hemichannels with carbenoxolone, probenecid or 10Panx1 peptide, P2X7 receptor antagonists (BBG, A839977 or A740003) as well inhibition of the NFκB transcription factor with Bay 11-7082. The swelling-dependent fall in expression of the NFκB inhibitor IκB-α was reduced by treatment of cells with A839977 and in P2X7 knockout mice. In summary, our data suggest that mechanical trauma to the retina results in priming of the NLRP3 inflammasome components and upregulated IL-6 expression and release. This was dependent upon ATP release through pannexin hemichannels and autostimulation of the P2X7 receptor. Since the P2X7 receptor can also trigger inflammasome activation it appears to have a central role in linking mechanical strain to neuroinflammation

Polarized Cytokine Release Triggered by P2X7 Receptor from Retinal Pigmented Epithelial Cells Dependent on Calcium Influx

Cytokine release from non-inflammatory cells is a key step in innate immunity, and agonists triggering cytokine release are central in coordinating responses. P2X7 receptor (P2X7R) stimulation by extracellular ATP is best known to active the NLRP3 inflammasome and release IL-1β, but stimulation also leads to release of other cytokines. As cytokine signaling by retinal pigmented epithelial (RPE) cells is implicated in retinal neurodegeneration, the role of P2X7R in release of cytokine IL-6 from RPE cells was investigated. P2X7R stimulation triggered IL-6 release from primary mouse RPE, human iPS-RPE and human ARPE-19 cells. IL-6 release was polarized, with predominant rise across apical membranes. IL-6 release was inhibited by P2X7R antagonists A438079, A839977, and AZ10606120, but not the NRTI lamivudine (3TC), P2X1R antagonist NF279, or P2Y1R antagonist MRS2179. P2X7R-mediated IL-6 release required extracellular Ca2+ and was blocked by Ca2+ chelator BAPTA. IL-6 release and Ca2+ elevation occurred rapidly, consistent with vesicular IL-6 staining in unstimulated cells. P2X7R stimulation did not trigger IL-1β release in these unprimed cells. P2X7R-mediated IL-6 release was enhanced in RPE cells from the ABCA4-/- mouse model of retinal degeneration. In summary, P2X7R stimulation triggers rapid Ca2+-dependent IL-6 release across the apical membrane of RPE cells

Approaches for Detecting Lysosomal Alkalinization and Impaired Degradation in Fresh and Cultured RPE Cells: Evidence for a Role in Retinal Degenerations

Lysosomes contribute to a multitude of cellular processes, and the pH of the lysosomal lumen plays a central mechanistic role in many of these functions. In addition to controlling the rate of enzymatic degradation for material delivered through autophagic or phagocytotic pathways, lysosomal pH regulates events such as lysosomal fusion with autophagosomes and the release of lysosomal calcium into the cytoplasm. Disruption of either the steady state lysosomal pH or of the regulated manipulations to lysosomal pH may be pathological. For example, chloroquine elevates the lysosomal pH of retinal pigmented epithelial (RPE) cells and triggers a retinopathy characterized by the accumulation of lipofuscin-like material in both humans and animals. Compensatory responses to restore lysosomal pH are observed; new data illustrate that chronic chloroquine treatment increases mRNA expression of the lysosomal/autophagy master transcription factor TcFEB and of the vesicular proton pump vHATPase in the RPE/choroid of mice. An elevated lysosomal pH with upregulation of TcFEB and vHATPase resembles the pathology in fibroblasts of patients with mutant presenilin 1 (PS1), suggesting a common link between age-related macular degeneration (AMD) and Alzheimer\u27s disease. While the absolute rise in pH is often small in these disorders, elevations of only a few tenths of a pH unit can have a major impact on both lysosomal function and the accumulation of waste over decades. Accurate measurement of lysosomal pH can be complex, and imprecise measurements have clouded the field. Protocols to optimize pH measurement from fresh and cultured cells are discussed, and indirect measurements to confirm changes in lysosomal pH and degradative capacity are addressed. The ability of reacidifying treatments to restore degradative function confirms the central role of lysosomal pH in these disorders and identifies potential approaches to treat diseases of lysosomal accumulation like AMD and Alzheimer\u27s disease. In summary, various approaches to determine lysosomal pH in fresh and cultured cells, as well as the potential to restore pH levels to an optimal range, can help identify and repair pathologies associated with lysosomal defects in RPE cells and perhaps also suggest new approaches to treat lysosomal storage diseases throughout the body. © 2014 Elsevier Ltd

Manejo integrado de pragas de grãos armazenados.

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Stimulation of TLR3 Triggers Release of Lysosomal ATP in Astrocytes and Epithelial cells that Requires TRPML1 Channels

Cross-reactions between innate immunity, lysosomal function, and purinergic pathways may link signaling systems in cellular pathologies. We found activation of toll-like receptor 3 (TLR3) triggers lysosomal ATP release from both astrocytes and retinal pigmented epithelial (RPE) cells. ATP efflux was accompanied by lysosomal acid phosphatase and beta hexosaminidase release. Poly(I:C) alkalinized lysosomes, and lysosomal alkalization with bafilomycin or chloroquine triggered ATP release. Lysosomal rupture with glycyl-L-phenylalanine-2-naphthylamide (GPN) eliminated both ATP and acid phosphatase release. Secretory lysosome marker LAMP3 colocalized with VNUT, while MANT-ATP colocalized with LysoTracker. Unmodified membrane-impermeant 21-nt and “non-targeting” scrambled 21-nt siRNA triggered ATP and acid phosphatase release, while smaller 16-nt RNA was ineffective. Poly(I:C)-dependent ATP release was reduced by TBK-1 block and in TRPML1−/− cells, while TRPML activation with ML-SA1 was sufficient to release both ATP and acid phosphatase. The ability of poly(I:C) to raise cytoplasmic Ca2+ was abolished by removing extracellular ATP with apyrase, suggesting ATP release by poly(I:C) increased cellular signaling. Starvation but not rapamycin prevented lysosomal ATP release. In summary, stimulation of TLR3 triggers lysosomal alkalization and release of lysosomal ATP through activation of TRPML1; this links innate immunity to purinergic signaling via lysosomal physiology, and suggests even scrambled siRNA can influence these pathways