19 research outputs found

    Macrophage fumarate hydratase restrains mtRNA-mediated interferon production

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    Metabolic rewiring underlies the effector functions of macrophages1-3, but the mechanisms involved remain incompletely defined. Here, using unbiased metabolomics and stable isotope-assisted tracing, we show that an inflammatory aspartate-argininosuccinate shunt is induced following lipopolysaccharide stimulation. The shunt, supported by increased argininosuccinate synthase (ASS1) expression, also leads to increased cytosolic fumarate levels and fumarate-mediated protein succination. Pharmacological inhibition and genetic ablation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) further increases intracellular fumarate levels. Mitochondrial respiration is also suppressed and mitochondrial membrane potential increased. RNA sequencing and proteomics analyses demonstrate that there are strong inflammatory effects resulting from FH inhibition. Notably, acute FH inhibition suppresses interleukin-10 expression, which leads to increased tumour necrosis factor secretion, an effect recapitulated by fumarate esters. Moreover, FH inhibition, but not fumarate esters, increases interferon-ÎČ production through mechanisms that are driven by mitochondrial RNA (mtRNA) release and activation of the RNA sensors TLR7, RIG-I and MDA5. This effect is recapitulated endogenously when FH is suppressed following prolonged lipopolysaccharide stimulation. Furthermore, cells from patients with systemic lupus erythematosus also exhibit FH suppression, which indicates a potential pathogenic role for this process in human disease. We therefore identify a protective role for FH in maintaining appropriate macrophage cytokine and interferon responses

    Whole genome analysis of a schistosomiasis-transmitting freshwater snail

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    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis

    Dexamethasone intravitreal implant in previously treated patients with diabetic macular edema : Subgroup analysis of the MEAD study

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    Background: Dexamethasone intravitreal implant 0.7 mg (DEX 0.7) was approved for treatment of diabetic macular edema (DME) after demonstration of its efficacy and safety in the MEAD registration trials. We performed subgroup analysis of MEAD study results to evaluate the efficacy and safety of DEX 0.7 treatment in patients with previously treated DME. Methods: Three-year, randomized, sham-controlled phase 3 study in patients with DME, best-corrected visual acuity (BCVA) of 34.68 Early Treatment Diabetic Retinopathy Study letters (20/200.20/50 Snellen equivalent), and central retinal thickness (CRT) 65300 \u3bcm measured by time-domain optical coherence tomography. Patients were randomized to 1 of 2 doses of DEX (0.7 mg or 0.35 mg), or to sham procedure, with retreatment no more than every 6 months. The primary endpoint was 6515-letter gain in BCVA at study end. Average change in BCVA and CRT from baseline during the study (area-under-the-curve approach) and adverse events were also evaluated. The present subgroup analysis evaluated outcomes in patients randomized to DEX 0.7 (marketed dose) or sham based on prior treatment for DME at study entry. Results: Baseline characteristics of previously treated DEX 0.7 (n = 247) and sham (n=261) patients were similar. In the previously treated subgroup, mean number of treatments over 3 years was 4.1 for DEX 0.7 and 3.2 for sham, 21.5 % of DEX 0.7 patients versus 11.1 % of sham had 6515-letter BCVA gain from baseline at study end (P = 0.002), mean average BCVA change from baseline was +3.2 letters with DEX 0.7 versus +1.5 letters with sham (P = 0.024), and mean average CRT change from baseline was -126.1 \u3bcm with DEX 0.7 versus -39.0 \u3bcm with sham(P < 0.001). Cataract-related adverse events were reported in 70.3 % of baseline phakic patients in the previously treated DEX 0.7 subgroup; vision gains were restored following cataract surgery. Conclusions: DEX 0.7 significantly improved visual and anatomic outcomes in patients with DME previously treated with laser, intravitreal anti-vascular endothelial growth factor, intravitreal triamcinolone acetonide, or a combination of these therapies. The safety profile of DEX 0.7 in previously treated patients was similar to its safety profile in the total study population

    Stranding continental crustal fragments during continent breakup: Mantle suture reactivation in the Nain Province of Eastern Canada

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    Earth’s continental crust has evolved through a series of supercontinent cycles, resulting in a patchwork of Archean cores surrounded by terranes, fragments, and slivers of younger crustal additions. However, the dispersal (and/or stranding) of continental fragments during breakup is not well understood. Inherited structures from previous tectonic activity may explain the generation of continental terranes by controlling first-order deformation during rifting. Here, we explored the influence of lithospheric deformation related to ancient orogenesis, focusing on the impact of the Torngat orogen in the genesis of the Nain Province continental fragment in Eastern Canada. We present three-dimensional continental extension models in the presence of an inherited lithospheric structure and show that a narrow continental terrane could be separated and stranded by deep lithospheric scarring. The results show that continental terranes formed by this method would be limited to a width of 100–150 km, imposed by tectonic conditions during continental suturing. The findings have broad implications, demonstrating an original theory on the fundamental geologic problem of terrane generation and continent breakup

    Amino Acid Analysis

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    Amino acid analysis is used to determine the amino acid content of amino acid–, peptide- and protein-containing samples. With minor exceptions, proteins are long linear polymers of amino acids connected to each other via peptide bonds. The first step of amino acid analysis involves hydrolyzing these peptide bonds. The liberated amino acids are then separated, detected, and quantified. The method was first developed by Moore, Stein and coworkers in the 1950s using HCl acid hydrolysis, and, despite considerable effort by many workers, the basic methodology remains relatively unchanged. This unit provides an overview and strategic planning for amino acid analysis, discussing a range of methodologies and issues. In addition, several common methods used for analysis of l-amino acids are described in detail, including: HCl acid hydrolysis, performic acid oxidation for methionine and cysteine analysis, base hydrolysis for tryptophan analysis, analysis of free amino acids, and analysis of reactive lysine

    Aspectos da biologia reprodutiva de Jatropha curcas L Reproductive biology aspects of Jatropha curcas L

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    O conhecimento da estrutura floral e da biologia reprodutiva numa cultura Ă© bĂĄsico para que o melhorista desenvolva tĂ©cnicas de castração e polinização adequadas. Objetivando obter dados de biologia reprodutiva de pinhĂŁo manso, inflorescĂȘncias emasculadas, foram observadas sem isolamento (controle positivo) e isoladas com tecido "nylon" tipo voal para posterior realização dos tratamentos de geitonogamia e xenogamia apĂłs a antese. Os tratamentos consistiram de controle positivo (flores nĂŁo isoladas), e a partir das flores isoladas foram obtidos os demais tratamentos: controle negativo (sem polinização); xenogamia (receberam pĂłlen de outra planta); geitonogamia 1 (receberam pĂłlen da mesma inflorescĂȘncia); geitonogamia 2 (receberam pĂłlen de outra inflorescĂȘncia da mesma planta). Os resultados indicam que a espĂ©cie nĂŁo apresenta problemas de autoincompatibilidade, sendo os Ă­ndices de fecundação bastante elevados e indiferentes estatisticamente em todos os tratamentos, com valores acima de 80%, exceto para o controle negativo em que as inflorescĂȘncias foram isoladas e nĂŁo polinizadas, resultando em ausĂȘncia de fecundação e de frutos. Esse Ășltimo resultado mostra a importĂąncia da visitação de insetos para a obtenção de sucesso no processo reprodutivo da espĂ©cie. As flores masculinas, doadoras de pĂłlen, abrem no perĂ­odo da manhĂŁ, assim como as femininas. Sendo assim, embora haja visitação de insetos durante todo o dia, o processo de polinização ocorre no perĂ­odo matutino, em razĂŁo da quase total ausĂȘncia de pĂłlen no perĂ­odo vespertino.<br>The knowledge of the floral structure and reproductive biology are basic to a more successful for the development of techniques of castration and pollination in plant species. Aiming to obtain data about reproductive biology of physyc nut, free and enclosed inflorescences were observed without isolation (positive control) and isolation with nylon for posterior treatment of geitonogamy and xenogamy. So, treatments were positive control (free or unbagged inflorescences), and all other treatments obtained from isolated immature inflorescences enclosed within of fine nylon bags: negative control (without pollination), xenogamy (receiving pollen from another plant); geitonogamy 1 (received pollen from the same inflorescence), geitonogamy 2 (received pollen from another inflorescence of the same plant). The results indicate that the species does not present problems of self-incompatibility resulting in high fertilization and statistically indifferent in all treatments, presenting values above 80%, except for negative control in which the inflorescences were isolated and not pollinated resulting in lack of fertilization and fruit development. These results show the importance insects for success in the reproductive process of this species. The male flowers, pollen donors, opened in the morning, just like the female ones. Thus, although there is visitation of insects during all the day, the process of pollination occurs in the morning, and almost total absence of pollen was observed after noon
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