57 research outputs found

    Role of CFTR expressed by neutrophils in modulating acute lung inflammation and injury in mice

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    Objective and designCystic fibrosis transmembrane conductance regulator (CFTR) regulates infection and inflammation. In this study, we investigated whether a lack of functional CFTR in neutrophils would promote lipopolysaccharide (LPS)-induced lung inflammation and injury.Materials and methodsCFTR-inhibited or F508del-CFTR-mutated neutrophils were stimulated with LPS and cultured to evaluate production of cytokines and NF-κB activation. Wild-type mice were reconstituted with F508del neutrophils or bone marrow and then intratracheally challenged with LPS to observe lung inflammatory response.ResultsPharmacologic inhibition and genetic mutation of CFTR in neutrophils activated NF-κB and facilitated macrophage inflammatory protein-2 (MIP-2) and tumor necrosis factor-α (TNF-α) production. Wild-type mice reconstituted with F508del neutrophils and bone marrow had more severe lung inflammation and injury after LPS challenge compared to wild-type mice receiving wild-type neutrophils or bone marrow reconstitution.ConclusionsLack of functional CFTR in neutrophils can promote LPS-induced acute lung inflammation and injury

    Inactivation of VCP/ter94 Suppresses Retinal Pathology Caused by Misfolded Rhodopsin in Drosophila

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    The most common Rhodopsin (Rh) mutation associated with autosomal dominant retinitis pigmentosa (ADRP) in North America is the substitution of proline 23 by histidine (RhP23H). Unlike the wild-type Rh, mutant RhP23H exhibits folding defects and forms intracellular aggregates. The mechanisms responsible for the recognition and clearance of misfolded RhP23H and their relevance to photoreceptor neuron (PN) degeneration are poorly understood. Folding-deficient membrane proteins are subjected to Endoplasmic Reticulum (ER) quality control, and we have recently shown that RhP23H is a substrate of the ER–associated degradation (ERAD) effector VCP/ter94, a chaperone that extracts misfolded proteins from the ER (a process called retrotranslocation) and facilitates their proteasomal degradation. Here, we used Drosophila, in which Rh1P37H (the equivalent of mammalian RhP23H) is expressed in PNs, and found that the endogenous Rh1 is required for Rh1P37H toxicity. Genetic inactivation of VCP increased the levels of misfolded Rh1P37H and further activated the Ire1/Xbp1 ER stress pathway in the Rh1P37H retina. Despite this, Rh1P37H flies with decreased VCP function displayed a potent suppression of retinal degeneration and blindness, indicating that VCP activity promotes neurodegeneration in the Rh1P37H retina. Pharmacological treatment of Rh1P37H flies with the VCP/ERAD inhibitor Eeyarestatin I or with the proteasome inhibitor MG132 also led to a strong suppression of retinal degeneration. Collectively, our findings raise the possibility that excessive retrotranslocation and/or degradation of visual pigment is a primary cause of PN degeneration

    Trace Levels of Innate Immune Response Modulating Impurities (IIRMIs) Synergize to Break Tolerance to Therapeutic Proteins

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    Therapeutic proteins such as monoclonal antibodies, replacement enzymes and toxins have significantly improved the therapeutic options for multiple diseases, including cancer and inflammatory diseases as well as enzyme deficiencies and inborn errors of metabolism. However, immune responses to these products are frequent and can seriously impact their safety and efficacy. Of the many factors that can impact protein immunogenicity, this study focuses on the role of innate immune response modulating impurities (IIRMIs) that could be present despite product purification and whether these impurities can synergize to facilitate an immunogenic response to therapeutic proteins. Using lipopolysaccharide (LPS) and CpG ODN as IIRMIs we showed that trace levels of these impurities synergized to induce IgM, IFNγ, TNFα and IL-6 expression. In vivo, trace levels of these impurities synergized to increase antigen-specific IgG antibodies to ovalbumin. Further, whereas mice treated with human erythropoietin showed a transient increase in hematocrit, those that received human erythropoietin containing low levels of IIRMIs had reduced response to erythropoietin after the 1st dose and developed long-lasting anemia following subsequent doses. This suggests that the presence of IIRMIs facilitated a breach in tolerance to the endogenous mouse erythropoietin. Overall, these studies indicate that the risk of enhancing immunogenicity should be considered when establishing acceptance limits of IIRMIs for therapeutic proteins

    Perturbation of Host Nuclear Membrane Component RanBP2 Impairs the Nuclear Import of Human Immunodeficiency Virus -1 Preintegration Complex (DNA)

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    HIV-1 is a RNA virus that requires an intermediate DNA phase via reverse transcription (RT) step in order to establish productive infection in the host cell. The nascent viral DNA synthesized via RT step and the preformed viral proteins are assembled into pre-integration complex (PIC) in the cell cytoplasm. To integrate the viral DNA into the host genome, the PIC must cross cell nuclear membrane through the nuclear pore complex (NPC). RanBP2, also known as Nup358, is a major component of the cytoplasmic filaments that emanates from the nuclear pore complex and has been implicated in various nucleo-cytoplasmic transport pathways including those for HIV Rev-protein. We sought to investigate the role of RanBP2 in HIV-1 replication. In our investigations, we found that RanBP2 depletion via RNAi resulted in profound inhibition of HIV-1 infection and played a pivotal role in the nuclear entry of HIV DNA. More precisely, there was a profound decline in 2-LTR DNA copies (marker for nuclear entry of HIV DNA) and an unchanged level of viral reverse transcription in RanBP2-ablated HIV-infected cells compared to RanBP3-depleted or non-specific siRNA controls. We further demonstrated that the function of Rev was unaffected in RanBP2-depleted latently HIV infected cells (reactivated). We also serendipitously found that RanBP2 depletion inhibited the global ectopic gene expression. In conclusion, RanBP2 is a host factor that is involved in the nuclear import of HIV-1 PIC (DNA), but is not critical to the nuclear export of the viral mRNAs or nucleo-cytoplasmic shuttling of Rev. RanBP2 could be a potential target for efficient inhibition of HIV

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    Not AvailableOrchids account for a large share of global floriculture trade and are estimated around 10% of international fresh cut flower trade. They have taken a significant position in cut flower industry due to its attractiveness, diversity in forms, shape and color, high productivity, right season of bloom, and easy packing and transportation. Postharvest life of orchid cut flowers is influenced by pre-harvest factors like varietal or species differences light intensity, sugar level of flowers, temperature and water loss. It is also affected by harvest factors such as time and stage of harvest and postharvest factors viz. ethylene production, precooling, pulsing, use of preservatives, packaging and storage. The hybrids of Dendrobium, Vanda and Mokara remain perfect from 7 days to 30 days. The flowers of Cattleya and Phalaenopsis remain fresh for 1 to 4 weeks whereas Aranda lasts for 18 to 28 days. Higher sugar levels of flowers improve longevity of cut flowers. The optimum harvesting stage of commercial orchids is fully open and mature flowers. In Cymbidium hyb. ‘PCMV’, harvest at two buds opened stage had maximum vase life (66.8 days). Ethylene is the main factor responsible for early senescence. In Cymbidium hybrid ‘Red Princess’ pulsing with 5% sucrose increases vase life upto 56 days. Pulsing with 4 mM STS for 10 minutes in Aranda and 0.5 mM STS for 24 hours in Phalaenopsis blocks the deleterious effect of ethylene. In tropical orchids like Dendrobium and Oncidium, AgNO3 (10-30 ppm) and HQS (50-100 ppm) extends vase life and bud opening of cut flowers. In Cymbidium, 1-MCP and AVG are superior to STS in prolonging the vase life of cut flowers. In Cymbidium ‘PCMV’, highest per cent of fully opened buds (75%) and maximum vase life (45 days) were recorded with the chemical combination of sugar 4% + salicylic acid 200 ppm. In orchids, cut spikes are inserted in tube containing water or water with preservatives and bunch of 5 or more or individual spikes are placed inside the CFB box in alternate fashion. Cool growing orchids are stored at lower temperature even at 5°C in cold chambers whereas tropical and subtropical orchids are stored at 7-10°C and 90-95% relative humidity.Not Availabl

    Not Available

    No full text
    Not AvailableOrchids account for a large share of global floriculture trade and are estimated around 10% of international fresh cut flower trade. They have taken a significant position in cut flower industry due to its attractiveness, diversity in forms, shape and color, high productivity, right season of bloom, and easy packing and transportation. Postharvest life of orchid cut flowers is influenced by pre-harvest factors like varietal or species differences, light intensity, sugar level of flowers, temperature and water loss. It is also affected by harvest factors such as time and stage of harvest and postharvest factors viz. ethylene production, precooling, pulsing, use of preservatives, packaging and storage. The hybrids of Dendrobium, Vanda and Mokara remain perfect from 7 days to 30 days. The flowers of Cattleya and Phalaenopsis remain fresh for 1 to 4 weeks whereas Aranda lasts for 18 to 28 days. Higher sugar levels of flowers improve longevity of cut flowers. The optimum harvesting stage of commercial orchids is fully open and mature flowers. In Cymbidium hyb. ‘PCMV’, harvest at two buds opened stage had maximum vase life (66.8 days). Ethylene is the main factor responsible for early senescence. In Cymbidium hybrid ‘Red Princess’ pulsing with 5% sucrose increases vase life upto 56 days. Pulsing with 4 mM STS for 10 minutes in Aranda and 0.5 mM STS for 24 hours in Phalaenopsis blocks the deleterious effect of ethylene. In tropical orchids like Dendrobium and Oncidium, AgNO3 (10-30 ppm) and HQS (50-100 ppm) extends vase life and bud opening of cut flowers. In Cymbidium, 1-MCP and AVG are superior to STS in prolonging the vase life of cut flowers. In Cymbidium ‘PCMV’, highest per cent of fully opened buds (75%) and maximum vase life (45 days) were recorded with the chemical combination of sugar 4% + salicylic acid 200 ppm. In orchids, cut spikes are inserted in tube containing water or water with preservatives and bunch of 5 or more or individual spikes are placed inside the CFB box in alternate fashion. Cool growing orchids are stored at lower temperature even at 5°C in cold chambers whereas tropical and subtropical orchids are stored at 7-10°C and 90-95% relative humidity.Not Availabl

    Stereochemical Rules Govern the Soft Self‐Assembly of Achiral Compounds: Understanding the Heliconical Liquid‐Crystalline Phases of Bent‐Core Mesogens

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    A series of bent‐shaped 4‐cyanoresorcinol bisterephthalates is reported. Some of these achiral compounds spontaneously form a short‐pitch heliconical lamellar liquid‐crystalline phase with incommensurate 3‐layer pitch and the helix axis parallel to the layer normal. It is observed at the paraelectric‐(anti)ferroelectric transition, if it coincides with the transition from random to uniform tilt and with the transition from anticlinic to synclinic tilt correlation of the molecules in the layers of the developing tilted smectic phase. For compounds with long chains the heliconical phase is only field‐induced, but once formed it is stable in a distinct temperature range, even after switching off the field. The presence of the helix changes the phase properties and the switching mechanism from the naturally preferred rotation around the molecular long axis, which reverses the chirality, to a precession on a cone, which retains the chirality. These observations are explained by diastereomeric relations between two coexisting modes of superstructural chirality. One is the layer chirality, resulting from the combination of tilt and polar order, and the other one is the helical twist evolving between the layers. At lower temperature the helical structure is replaced by a non‐tilted and ferreoelectric switching lamellar phase, providing an alternative non‐chiral way for the transition from anticlinic to synclinic tilt
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